JP3886093B2 - Boom work vehicle safety device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a safety device for a boom working vehicle having a boom that can be raised and lowered on a vehicle body.
[0002]
[Prior art]
As an example of such a boom working vehicle, a boom type aerial work vehicle in which a work platform is attached to the tip of the crane vehicle or the boom is known, and in such a boom working vehicle, a fall that acts on the vehicle body is known. A safety device is provided to prevent the vehicle body from falling due to an excessive moment. There are various types of such safety devices. For example, a moment limiter system that prohibits boom operation (boom collapse and extension operations) in a direction in which the overturning moment increases after the overturning moment has reached a limit value. In addition, there is a movement range regulation method that prohibits boom operation (boom collapse operation and extension operation) in a direction in which the tip of the boom deviates from an allowable movement range determined in accordance with the load.
[0003]
[Problems to be solved by the invention]
However, in these safety devices, the boom is lifted up by pushing up the structure (for example, the lower surface of the bridge) at the tip of the boom (the work platform in the case of an aerial work vehicle). When the load load increases and the overturning moment reaches the limit value (or the position of the tip of the boom reaches the limit position of the permissible movement range), the boom collapses and the extension operation is prohibited. There is no method for moving the work platform other than the above, and there may be a case where the boom cannot be moved at all in a situation in which the boom cannot be contracted, and the robot may get stuck. In such a case, if the boom operation restriction is canceled and the boom is fallen over, etc., it is possible to escape from the stuck state, but it is preferable to avoid such restriction release by the operator as much as possible.
[0004]
The present invention has been made in view of such problems, and the load load at the tip of the boom is increased by the lifting operation of the boom such as pushing up the structure, whereby the overturning moment reaches the limit value, or the boom Boom operation that enables the boom to be safely moved by the operator without releasing the operation restriction when the position of the tip of the arm reaches the limit position of the allowable movement range and the boom operation restriction has been activated The purpose is to provide a car safety device.
[0005]
[Means for Solving the Problems]
In order to achieve such an object, the first aspect of the present invention provides a vehicle body, a boom that is provided on the vehicle body so as to be able to be raised and lowered, and an operation input from the outside (for example, an operation from the boom operation lever 51 in the embodiment). The boom operation control means (for example, the valve drive signal generation unit 61, the valve drive unit 62, and the control valves V1 to V3 of the controller 60 in the embodiment) that controls the boom to move up and down according to the input) and the vehicle body Whether the overturning moment detected by the overturning moment detecting means (for example, the axial force detector 71 in the embodiment and the overturning moment calculating unit 63 of the controller 60) and the overturning moment detecting means detected by the overturning moment detecting means has reached a limit value. Determination means for determining whether or not (for example, the determination unit 64 of the controller 60 in the embodiment); When the means determines that the overturning moment has reached the limit value, the boom operation control means prohibits the boom operation in the direction in which the overturning moment exceeds the limit value (for example, the controller 60 in the embodiment). In a safety device for a boom work vehicle (for example, an aerial work vehicle 1 in the embodiment) having a restriction unit 65 and a valve drive signal generation unit 61), it is determined by the determination means that the overturning moment has reached a limit value. Boom operation detecting means (for example, the operation signal storage unit 66 and the boom operation detecting unit 67 of the controller 60 in the embodiment) for detecting the boom operation immediately before the determination by the determining unit is made, and the boom operation is performed. Immediately before the detection means determines that the overturning moment has reached the limit value by the determination means. When the boom operation that is detected that were Okoshiossha operation without extension of the boom Determines that the tip of the boom is stuck or pressed against the structure, The regulating means ends the state where the judging means judges that the overturning moment has reached the limit value. Up to If it is a lying down operation without boom extension by the boom operation control means, it is allowed.
[0006]
In this safety device, the overturning moment acting on the vehicle body is detected by the overturning moment detecting means, and it is judged by the judging means whether or not the overturning moment detected by the overturning moment detecting means has reached a limit value. When the determination means determines that the overturning moment has reached the limit value, the operation of the boom in the direction in which the overturning moment exceeds the limit value is restricted by the restriction means. When the determination means determines that the overturning moment has reached the limit value, the boom operation detection means detects the boom operation immediately before the determination means makes the determination, and the boom operation detection means detects this. If the boom operation is a lifting operation that does not involve boom extension, the regulating means will extend the boom until the judgment means determines that the overturning moment has reached the limit value. Try to allow the lodging without accompanying.
[0007]
As described above, in the safety device for a boom working vehicle according to the first aspect of the present invention, when the overturning moment acting on the vehicle body has reached the limit value, the boom operation in the direction in which the overturning moment exceeds the limit value is performed. The situation where the vehicle body is toppled by being prohibited is prevented.However, if the boom operation just before the tipping moment reaches the limit value is a lifting operation without boom extension, the tipping moment will reach the limit value. Until the reaching state is completed, the overturning operation without extending the boom, that is, the operation of simply overturning the boom and the overturning operation while contracting the boom are allowed. For this reason, even if the structure is pushed up by the raising and lowering operation of the boom and the overturning moment reaches the limit value and the operation restriction works, the operator must release the action restriction as before. You can safely move the boom and get out of the way.
[0008]
Further, in such a restricted state, the boom overturning operation is allowed until the state where the overturning moment has reached the limit value, that is, until the restriction itself is released. Alternatively, when the boom operation with extension is performed and the restriction state is reached, the original restriction works and the boom collapse and extension operation is prohibited to prevent the vehicle body from falling, but part of such operation restriction Since the treatment corresponding to the release is not performed by the operator's own will, the restriction release state is not left forgotten as it is, and the safety is high.
[0009]
In the second aspect of the present invention, a boom is provided in accordance with a vehicle body, a boom that is provided on the vehicle body so that it can be raised and lowered, and an operation input from the outside (for example, an operation input from the boom operation lever 51 in the embodiment). Boom operation control means (for example, the valve drive signal generation unit 161, the valve drive unit 162, and the control valves V1 to V3 of the controller 160 in the embodiment) that performs the control of raising and lowering or expanding and contracting, and the load load ( Load detecting means (for example, load detector 74 in the embodiment) for detecting a downward load), position detecting means for detecting the position of the tip of the boom relative to the vehicle body (for example, the undulation angle detector 75 in the embodiment, length) Detector 76, turning angle detector 72, position calculation unit 163 of controller 160, and boom detected by the position detection means. Judgment means for judging whether or not the position of the end portion has reached the limit position of the allowable movement range determined in accordance with the load load detected by the load detection means (for example, the judgment unit 164 of the controller 160 in the embodiment). ) And the direction in which the position of the tip of the boom deviates from the allowable movement range by the boom operation control means when the determination means determines that the position of the tip of the boom has reached the limit position of the allowable movement range. In a safety device for a boom working vehicle having restriction means (for example, the restriction part 165 of the controller 160 and the valve drive signal generation part 161 in the embodiment) that prohibits the operation of the boom of the vehicle, the position of the tip of the boom is determined by the judgment means When it is determined that has reached the limit position of the allowable movement range, the boom operation immediately before the determination by the determination means is performed. Boom operation detection means (for example, the operation signal storage unit 166 and the boom operation detection unit 167 of the controller 160 in the embodiment) are provided, and the boom operation detection unit allows the position of the tip of the boom to be within the allowable movement range by the determination unit. When it is detected that the movement of the boom immediately before it is determined that the limit position has been reached is a lifting movement that does not extend the boom Determines that the tip of the boom is stuck or pressed against the structure, The restricting means ends the state where the judging means judges that the position of the tip of the boom has reached the limit position of the allowable movement range. Up to If it is a lying down operation without boom extension by the boom operation control means, it is allowed.
[0010]
In this safety device, the position of the boom tip with respect to the vehicle body is detected by the position detection means, and the detected position of the boom tip is applied to the load applied to the boom tip detected by the load detection means. It is judged by the judging means whether or not the limit position of the permissible movement range determined correspondingly has been reached. When it is determined by the determining means that the position of the tip of the boom has reached the limit position of the allowable movement range, the operation of the boom in a direction in which the position of the tip of the boom deviates from the allowable movement range is regulated. To regulate. Further, when it is determined by the determining means that the position of the tip of the boom has reached the limit position of the allowable movement range, the boom operation detecting means detects the boom operation immediately before the determination by the determining means, When the boom motion detected by the boom motion detection means is a lifting motion without boom extension, the restriction means causes the judgment means to bring the position of the tip of the boom to the limit position of the allowable movement range. Until the state judged to have reached is completed, the fall operation without the extension of the boom is allowed.
[0011]
As described above, in the safety device for a boom working vehicle according to the second aspect of the present invention, the position of the tip of the boom relative to the vehicle body is set to the limit position of the allowable movement range determined in accordance with the load applied to the tip of the boom. In this case, the boom operation is prohibited in a direction in which the position of the tip end of the boom deviates from the allowable movement range and the vehicle body falls. If the boom operation just before reaching the limit position is a lifting operation without boom extension, the boom position is not reached until the end of the boom reaches the limit position of the allowable movement range. An overturning operation without extension, that is, an operation of simply overturning the boom and an operation of overturning while contracting the boom are allowed. Thereby, the same effect as the safety device according to the first aspect of the present invention can be obtained.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows a boom type aerial work vehicle equipped with a safety device according to the first aspect of the present invention, and FIG. 1 is a block diagram showing the configuration of the safety device. The aerial work vehicle 1 includes a vehicle body 10 having a tire wheel 11 and capable of traveling on a road, a boom 30 attached to a swivel base 20 provided on the vehicle body 10 in a undulating manner, and a tip portion of the boom 30. And a work table 40 that is mounted so as to be able to swing horizontally (swing).
[0013]
The swivel base 20 is attached to the rear portion of the vehicle body 10, and the boom 30 can be swung by rotating around a vertical axis by hydraulically driving a swivel motor 23 built in the vehicle body 10. The boom 30 is pivotally connected to an upper end portion of a support column 21 formed so as to extend above the swivel base 20 by a foot pin 22, and is lifted by hydraulically driving a hoisting cylinder 24 straddling the swivel base 20. It is possible to undulate in the lower surface. Further, the boom 30 is configured to be nested, and can be expanded and contracted in the longitudinal direction by hydraulically driving a built-in telescopic cylinder 31.
[0014]
A vertical post 32 is attached to the tip of the boom 30, and a bracket 41 of the work table 40 is attached so as to surround the periphery of the vertical post 32. The vertical post 32 is always held vertically by a hydraulic cylinder (not shown), and the floor surface of the work table 40 is always kept horizontal. Further, the bracket 41 of the work table 40 is provided with an electric swing motor 42, and the work table 40 can be swung around the vertical post 32 by electrically driving the swing motor 42. It is.
[0015]
Outrigger jacks 12 are provided at four positions in the front, rear, left and right of the vehicle body 10 so that they can be used by projecting sideways. In this way, by using the outrigger jacks 12 protruding to the side of the vehicle body 10, the vehicle body 10 in operation can be stabilized, and a large overturning moment acting on the vehicle body 10 can be resisted. .
[0016]
The operation box 50 provided in the work table 40 is provided with a boom operation lever 51 and a swing operation lever (not shown). The boom operation lever 51 is a so-called joystick-type lever, and can be tilted in any direction including 360 degrees including front, rear, left and right with respect to the neutral position, and clockwise and counterclockwise with respect to the neutral position. It is possible to perform a twisting operation. The swing operation lever can be tilted in the front-rear direction from the neutral position. By such tilting operation in the front-rear direction, the swing motor 42 can be rotated in both forward and reverse directions to swing the work table 40. Is possible.
[0017]
As shown in FIG. 1, the operation signal of the boom operation lever 51 is input to the valve drive signal generation unit 61 of the controller 60. The valve drive signal generation unit 61 outputs a signal for extending and retracting the hoisting cylinder 24 in response to the tilting operation of the boom operation lever 51 in the front-rear direction to the valve drive unit 62, and the boom operation lever 51 is tilted in the left-right direction. In response to this, a signal for expanding and contracting the telescopic cylinder 31 is output to the valve driving unit 62. In addition, a signal for rotating the turning motor 23 in the forward / reverse direction according to the twisting operation of the boom operation lever 51 around the axis is output to the valve drive unit 62.
[0018]
The valve drive unit 62 electromagnetically drives the control valves V <b> 1 to V <b> 3 corresponding to the hoisting cylinder 24, the telescopic cylinder 31, and the swing motor 23 based on the valve drive signal input from the valve drive signal generation unit 61. As a result, the hydraulic oil supplied from the hydraulic pump P to the hoisting cylinder 24, the telescopic cylinder 31, and the swing motor 23 is controlled, and the boom 30 performs hoisting, telescopic, and pivoting operations according to the operation of the boom operation lever 51.
[0019]
For this reason, the operator who has boarded the work table 40 operates the boom operation lever 51 and the swing operation lever from the operation box 50 to raise and lower the boom 30, to swing and turn the work table 40. The operator can move to a desired position and perform the work by himself / herself. However, the work vehicle 10 is to be overturned by the overturning moment acting on the vehicle body 10. A safety device is provided to prevent this, and the safety device will be described in detail below.
[0020]
This safety device is configured to detect the overturning moment acting on the vehicle body 10 and to regulate the operation of the boom 30 so that the detected overturning moment does not exceed the limit value. This limit value is variably set according to the turning angle of the swivel base 20 (that is, the turning angle of the boom 30) and the overhanging width of the outrigger jack 12, and the boom 30 is positioned in the front-rear direction of the vehicle body 10. When the boom 30 is located on the side of the vehicle body 10 or when the outrigger jack 12 is small, a small value is set. In addition, the overturning moment is affected by the undulation angle of the boom 30 and the length of the boom 30 in addition to the load applied to the tip of the boom 30 (loading weight of the work table 40), and acts on the tip of the boom 30. The larger the load load, the smaller the undulation angle of the boom 30, and the longer the boom 30, the greater the value.
[0021]
The overturning moment acting on the vehicle body 10 is obtained based on the magnitude of the axial force of the hoisting cylinder 24. For this reason, an axial force detector 71 for detecting the axial force acting on the hoisting cylinder 24 is provided at the lower end of the hoisting cylinder 24 (see FIG. 2), and the detected information is sent to the falling moment calculating unit 63 of the controller 60. It is designed to be entered. The overturning moment calculation unit 63 calculates the overturning moment acting on the vehicle body 10 based on the axial force of the undulation cylinder 24 detected by the axial force detector 71, and outputs this to the determination unit 64 of the controller 60.
[0022]
The determination unit 64 of the controller 60 determines whether or not the fall moment acting on the vehicle body 10 calculated by the fall moment calculating unit 63 has reached a limit value determined within a range in which the vehicle body 10 does not fall. The result is output to the restriction unit 65 of the controller 60. Here, the limit value is variably set according to the value of the turning angle of the swivel base 20 and the overhanging width of the outrigger jack 12 as described above. The rotation angle detector 72 (see also FIG. 2) provided and the overhang width detector 73 (not shown in FIG. 2) provided in the vicinity of each outrigger jack 12 are provided.
[0023]
When the determining unit 64 determines that the overturning moment has reached the limit value, the restricting unit 65 of the controller 60 generates a control signal for prohibiting the boom operation in the direction in which the overturning moment exceeds the limit value. To 61. Here, the boom operation in the direction in which the overturning moment exceeds the limit value is specifically the boom collapse and extension operations.
[0024]
When such a restriction signal is input from the restriction unit 65, the valve drive signal generation unit 61 first outputs a valve drive signal for stopping the operation of the boom 30 to the valve drive unit 62 to stop the operation of the boom 30. Subsequently, as shown in the table of FIG. 5, the fall and extension operations of the boom 30 that may further increase the falling moment are prohibited. That is, after the operation of the boom 30 is stopped, even if an operation signal for tilting or extending the boom 30 is output by operating the boom operation lever 51, these operation signals are ignored and a simple raising operation is performed. Only the operation signals corresponding to the operation (the operation only by the expansion operation of the hoisting cylinder 24), the simple contraction operation (the operation only by the contraction operation of the expansion cylinder 31) and the operation of rising while contracting are received. For this reason, when the operation is stopped during the operation of the boom 30, the operator starts from the restricted state, that is, from the state in which the determination unit 64 determines that the overturning moment has reached the limit value. I need to get out. Further, once the control state is exited, all the above control is released, and the normal boom operation becomes possible.
[0025]
FIG. 3 exemplifies a region R in which the distal end portion of the boom 30 that is set on the side of the vehicle body 10 can be moved corresponding to the turning angle of a certain boom 30 and the overhanging width of the outrigger jack 12. As shown in this figure, the limit line that makes it impossible to move the tip of the boom 30 when the overturning moment reaches the limit value is the substantially vertical line L on the outermost side of the region R. Then, when the tip of the boom 30 is positioned on the limit line L due to an operation accompanied by the fall or extension of the boom 30, the restriction is applied to the boom 30.
[0026]
In addition, the controller 60 determines that the overturning moment has reached the limit value in the operation signal storage unit 66 that sequentially updates the operation signal history of the boom operation lever 51 while storing the history of the operation signal, and the determination unit 64. Immediately before the determination by the determination unit 64 (determination that the overturning moment has reached the limit value) is made based on the history of the operation signal of the boom operation lever 51 stored in the operation signal storage unit 66. And a boom operation detecting unit 67 for detecting the operation of the boom 30 at the same time. When the determination unit 64 determines that the overturning moment has reached the limit value, the restriction unit 65 outputs the restriction signal to the valve drive signal generation unit 61 and the boom 30 detected by the boom operation detection unit 67. When the operation (the operation of the boom 30 immediately before the overturning moment reaches the limit value) is the raising operation without the boom 30 being extended, the determination unit 64 determines that the overturning moment has reached the limit value. Until the finished state is completed, an allowance signal that allows the lying down operation without the extension of the boom 30 is output to the valve drive signal generator 61.
[0027]
When the allowable signal is input together with the restriction signal from the restriction unit 65, the valve drive signal generation unit 61 first outputs a valve drive signal for stopping the operation of the boom 30 to the valve drive unit 62 to operate the boom 30. Next, as shown in the table of FIG. 5, the extension operation of the boom 30 that may increase the overturning moment is prohibited. Thereby, although the extension operation of the boom 30 is prohibited, the overturning operation without the extension becomes possible, and the operator reaches the limit value in the restricted state, that is, the judgment unit 64 by the overturning operation without the extension. It is possible to get out of the state judged to be. Further, if the regulation state is escaped, all the regulations are released, and the normal boom operation becomes possible.
[0028]
Here, the lifting operation without the boom 30 being extended is a simple lifting operation of the boom 30 and a lifting operation performed while the boom 30 is contracted. In the former case, the tip of the boom 30 ( The workbench 40) moves while drawing an arc orbit around the foot pin 22. Further, the case where the overturning moment reaches the limit value by the simple raising operation of the boom 30 is a case where the work table 40 is caught on the structure during the raising operation of the boom 30, or For example, the work table 40 may be pressed against the lower surface of a structure (for example, a bridge) during the raising operation of the boom 30.
[0029]
FIG. 4 shows that when the tip of the boom 30 (work table 40) is moved from the point P while the boom 30 is simply raised, the tip of the boom 30 is pressed against the lower surface S of the structure at the point Q. This shows an example in which the overturning moment has reached a limit value. Note that the tipping moment of the boom 30 does not always reach the limit value when the tip of the boom 30 is pressed against the lower surface S of the structure, and does not occur even after the tip of the boom 30 is pressed against the lower surface S of the structure. If the axial force of the hoisting cylinder 24 detected by the axial force detector 71 is increased, the possibility that the overturning moment will reach the limit value is raised.
[0030]
Thus, in the first aspect of the present invention, when the overturning moment acting on the vehicle body 10 increases and reaches the limit value, the operation of the boom 30 in the direction in which the overturning moment exceeds the limit value is prohibited, and the vehicle body 10 Although a situation of falling is prevented, if the operation of the boom 30 immediately before the falling moment reaches the limit value is a lifting operation that does not involve the extension of the boom 30, the falling moment has reached the limit value. Until the state is finished, the overturning operation without the boom 30 extending, that is, the operation of simply overturning the boom 30 and the operation of overturning the boom 30 while contracting are permitted. For this reason, even when the structure is pushed up by the raising operation of the boom 30 and the overturning moment reaches the limit value and the operation restriction of the boom 30 is activated, the operator restricts the operation as in the conventional case. It is possible to safely move the boom 30 without releasing the movement and escape from the stuck state.
[0031]
Further, in such a restricted state, the boom 30 is allowed to fall down until the state in which the overturning moment reaches the limit value, that is, until the restriction itself is released. When the boom operation accompanied by overturning or extending is performed and the restricted state is established, the original restriction works, and the overturning and extending operation of the boom 30 is prohibited to prevent the vehicle body 10 from falling over. The treatment corresponding to the partial release is not performed by the operator's own will, so the regulation release state is not left forgotten as it is, and the safety is high.
[0032]
Next, the safety device according to the second aspect of the present invention will be described. Since this safety device only changes the configuration of the controller in the safety device according to the first aspect of the present invention, the application target of the safety device according to the second aspect of the present invention is the aerial work vehicle 1, The description of the part will be omitted.
[0033]
As shown in FIG. 6, the operation signal of the boom operation lever 51 is input to the valve drive signal generation unit 161 of the controller 160, and the valve drive signal generation unit 161 responds to the tilting operation of the boom operation lever 51 in the front-rear direction. Then, a signal for extending and retracting the hoisting cylinder 24 is output to the valve drive unit 162, and a signal for extending and retracting the extendable cylinder 31 according to the tilting operation of the boom operation lever 51 in the left and right direction is output to the valve drive unit 162. Further, a signal for rotating the turning motor 23 in the forward / reverse direction according to the twisting operation of the boom operation lever 51 around the axis is output to the valve drive unit 162.
[0034]
The valve drive unit 162 electromagnetically drives the control valves V <b> 1 to V <b> 3 corresponding to the hoisting cylinder 24, the telescopic cylinder 31, and the swing motor 23 based on the valve drive signal input from the valve drive signal generation unit 161. As a result, the hydraulic oil supplied from the hydraulic pump P to the hoisting cylinder 24, the telescopic cylinder 31, and the swing motor 23 is controlled, and the boom 30 performs hoisting, telescopic, and pivoting operations according to the operation of the boom operation lever 51. As a result, the worker who has boarded the work table 40 can move to a desired position and perform work.
[0035]
In the safety device according to the second aspect of the present invention, the position of the tip of the boom 30 relative to the vehicle body 10 is detected, and the boom 30 is detected so that the detected position of the tip of the boom does not deviate from the set allowable movement range. The operation is restricted. This allowable movement range is set corresponding to the load applied to the tip of the boom 30 (downward load such as the worktable 40 load weight), the turning angle of the turntable 20 (that is, the turning angle of the boom 30) and the outrigger. Different areas are formed for each overhang width of the jack 12. Specifically, a narrower region is set as the load applied to the tip of the boom 30 is larger, and the narrower the region is, the smaller the boom 30 is located on the side of the vehicle body 10 and the smaller the overhanging width of the outrigger jack 12 is. . Here, the position of the tip of the boom 30 with respect to the vehicle body 10 is determined from the undulation angle detector 75 for detecting the undulation angle of the boom 30, the length detector 76 for detecting the length of the boom 30, and the aforementioned turning angle detector 72. The load load that is obtained by the position calculation unit 163 of the controller 160 that performs the calculation based on the detected information and acts on the tip of the boom 30 is detected by the load detector 74 provided at the tip of the boom 30.
[0036]
Based on information from the load detector 74, the turning angle detector 72, and the overhang detector 73, the determination unit 164 of the controller 160 determines the turning angle of the boom 30 and the overhang width of the outrigger jack 12 at that time, and the boom 30. The movement allowable region corresponding to the load applied to the front end of the vehicle (region where the front end of the boom 30 can be moved without overturning the vehicle body 10) is set, and the position of the front end of the boom 30 calculated by the position calculation unit 163 is Then, it is determined whether or not the limit position of the set movement allowable region has been reached, and the determination result is output to the restriction unit 165 of the controller 160. When the determining unit 164 determines that the position of the tip of the boom 30 has reached the limit position of the allowable movement range, the restricting unit 165 of the controller 160 deviates from the allowable moving range. The control signal for prohibiting the boom operation in the direction to be output is output to the valve drive signal generator 161. Here, the boom operation in the direction in which the position of the tip portion of the boom 30 deviates from the allowable movement range is specifically a boom collapse and extension operation. Note that the allowable movement range set in the determination unit 164 is substantially the region shown in FIG. 3 described above, and the limit position of the movement allowable region is a position corresponding to the line L in this figure.
[0037]
When such a restriction signal is input from the restriction unit 165, the valve drive signal generation unit 161 first outputs a valve drive signal for stopping the operation of the boom 30 to the valve drive unit 162 to stop the operation of the boom 30. As shown in the table of FIG. 5 described above, the boom 30 is prohibited from falling and extending, which may further increase the falling moment. That is, after the operation of the boom 30 is stopped, even if an operation signal for tilting or extending the boom 30 is output by operating the boom operation lever 51, these operation signals are ignored and a simple raising operation is performed. Only the operation signals corresponding to the operation (the operation only by the expansion operation of the hoisting cylinder 24), the simple contraction operation (the operation only by the contraction operation of the expansion cylinder 31) and the operation of rising while contracting are received. For this reason, when the operation is stopped during the operation of the boom 30, the operation is stopped by any of these boom operations, that is, the position of the tip of the boom 30 is set to the limit position of the allowable movement range in the determination unit 164. It is necessary to get out of the state judged to have reached. Further, once the control state is exited, all the above control is released, and the normal boom operation becomes possible.
[0038]
The controller 160 also includes an operation signal storage unit 166 that sequentially updates the operation signal history of the boom operation lever 51 while storing the history of the operation signal, and the position of the tip of the boom 30 in the determination unit 164 is within the allowable movement range. When it is determined that the limit position has been reached, the determination by the determination unit 164 (the position of the tip of the boom 30 is determined based on the history of the operation signal of the boom operation lever 51 stored in the operation signal storage unit 166). And a boom operation detector 167 that detects the operation of the boom 30 immediately before the determination that the limit position of the allowable movement range has been reached. When the determining unit 164 determines that the position of the tip of the boom 30 has reached the limit position of the set allowable movement range, the restricting unit 165 outputs the restricting signal to the valve drive signal generating unit 161. The operation of the boom 30 detected by the boom operation detection unit 167 (the operation of the boom 30 immediately before the position of the tip of the boom 30 reaches the limit position of the allowable movement range) is an ascending operation without the boom 30 being extended. If there is, the lowering operation without the extension of the boom 30 is allowed until the state where the determination unit 164 determines that the position of the tip of the boom 30 has reached the limit position of the allowable movement range is completed. The allowable signal is output to the valve drive signal generator 161.
[0039]
When the allowable signal is input together with the restriction signal from the restriction unit 165, the valve drive signal generation unit 161 first outputs a valve drive signal for stopping the operation of the boom 30 to the valve drive unit 162 to operate the boom 30. Next, as shown in the table of FIG. 5, the extension operation of the boom 30 that may cause the position of the tip of the boom 30 to deviate from the allowable movement range is prohibited. Thereby, although the extension operation of the boom 30 is prohibited, the overturning operation without extension is possible, and the operator can operate in this restricted state, that is, the position of the tip of the boom 30 in the determination unit 164 by the overturning operation without extension. Can exit from the state where it is determined that the limit position of the allowable movement range has been reached. Further, if the regulation state is escaped, all the regulations are released, and the normal boom operation becomes possible. Here, the raising operation without extension of the boom 30 is a simple raising operation of the boom 30 and a raising operation performed while the boom 30 is contracted as described above.
[0040]
As described above, in the second aspect of the present invention, when the position of the tip of the boom 30 with respect to the vehicle body 10 has reached the limit position of the allowable movement range determined corresponding to the load applied to the tip of the boom 30, Although the operation of the boom 30 in a direction in which the position of the tip of the boom 30 deviates from the allowable movement range is prohibited and the vehicle body 10 is prevented from falling, the position of the tip of the boom 30 is the limit of the allowable movement range. When the operation of the boom 30 immediately before reaching the position is a raising operation without the extension of the boom 30, the state in which the position of the tip of the boom 30 reaches the limit position of the allowable movement range is completed. An overturning operation that does not involve extension of the boom 30, that is, an operation of simply overturning the boom 30 and an operation of overturning the boom 30 while contracting is permitted. Thereby, the same effect as the safety device according to the first aspect of the present invention described above can be obtained.
[0041]
Although the embodiment of the present invention has been described so far, the scope of the present invention is not limited to the above. For example, in the first embodiment of the present invention, the means for detecting the overturning moment is configured to calculate the overturning moment based on the axial force of the hoisting cylinder 24. For example, the position of the base 40 relative to the vehicle body 10 may be detected, and the falling moment may be calculated based on these values. In the embodiments corresponding to the first and second aspects of the present invention, the operation of the controller 60 (160) is performed to detect the motion of the boom immediately before it is determined whether or not the overturning moment has reached the limit value. The history of the operation signal of the boom operation lever 51 stored in the signal storage unit 66 (166) is used, but instead of such a configuration, the operation state of the boom operation lever 51 or the operation of the hoisting cylinder 24 is related. It may be performed by detecting the operating state of the control valve V1.
[0042]
In the embodiment of the second aspect of the present invention, the allowable movement range of the tip of the boom 30 includes not only the load applied to the tip of the boom 30 but also the turning angle of the boom 30 and the overhanging width of the outrigger jack 12. Although the configuration is set as a parameter, it is only necessary that the allowable movement range be set in accordance with the load applied to the tip of the boom 30, and the turning angle of the boom 30 and the outrigger jack are not necessarily limited. It is not necessary to be variably set according to the overhang width of 12.
[0043]
In the above embodiment, the boom work vehicle (the aerial work vehicle 1) is driven by tire wheels, but may be driven by these crawler devices. Moreover, in the said embodiment, although the safety device of this invention was applied to the boom type aerial work vehicle, this invention is not restricted to such an aerial work vehicle, It is applied also to other boom work vehicles, such as a crane. Is possible. Furthermore, although the aerial work vehicle shown in the above embodiment is configured to turn the boom 30, the boom work vehicle to which the present invention is applied may not necessarily be capable of turning the boom 30.
[0044]
In the above embodiment, the overturning moment is the limit value due to the lifting operation of the boom 30 that pushes up the structure or the lifting operation of the boom 30 in a state where the heavy object is suspended by the winch provided on the work table 40. Even when the position of the tip of the boom 30 reaches the limit position of the allowable movement range, the operation of raising the boom 30 was possible, but in such a case, an excessive force is applied to the boom 30. Or a part of the tire wheel 11 may be lifted, so that when the boom 30 is lifted, the boom 30 may be lifted.
[0045]
【The invention's effect】
As described above, in the safety device for a boom working vehicle according to the first aspect of the present invention, when the overturning moment acting on the vehicle body reaches a limit value, the boom in a direction in which the overturning moment exceeds the limit value. However, if the boom operation just before the falling moment reaches the limit value is a rising motion without boom extension, the falling moment will be Until the state where the limit value has been reached is completed, the overturning operation without extension of the boom, that is, the operation of simply overturning the boom and the overturning operation while contracting the boom is allowed. For this reason, even if the boom is lifted up and the structure is pushed up, and the overturning moment reaches the limit value and the operation restriction is applied to the boom, the operator releases the operation restriction as before. You can safely move the boom without having to do it, and you can escape from being stuck.
[0046]
Further, in such a restricted state, the boom overturning operation is allowed until the state where the overturning moment has reached the limit value, that is, until the restriction itself is released. Alternatively, when the boom operation with extension is performed and the restriction state is reached, the original restriction works and the boom collapse and extension operation is prohibited to prevent the vehicle body from falling, but part of such operation restriction Since the treatment corresponding to the release is not performed by the operator's own will, the restriction release state is not left forgotten as it is, and the safety is high.
[0047]
In the safety device for a boom working vehicle according to the second aspect of the present invention, the position of the tip of the boom relative to the vehicle body reaches the limit position of the allowable movement range determined in accordance with the load applied to the tip of the boom. When the boom is in a position where the position of the boom tip departs from the allowable movement range, the movement of the boom is prohibited and the vehicle body is prevented from falling over. If the boom operation just before reaching the position was a lifting operation without boom extension, the boom extension was completed until the end of the boom reached the limit position of the allowable movement range. A tilting operation not accompanied by a boom, that is, an operation of simply tilting the boom and an operation of tilting the boom while contracting is permitted. Thereby, the same effect as the safety device according to the first aspect of the present invention can be obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a safety device for a boom working vehicle according to a first aspect of the present invention.
FIG. 2 is a side view of an aerial work vehicle that is an example of a boom work vehicle equipped with the safety device.
FIG. 3 is a rear view of an aerial work vehicle showing a region R in which the tip of the boom can move and a limit line L that makes it impossible to move the tip of the boom when the tipping moment reaches a limit value.
FIG. 4 is a rear view of an aerial work vehicle showing a state in which the boom tip is moved from a point P to a point Q while the boom is simply raised.
FIG. 5 is a chart showing the details of boom operation restrictions in the safety device according to the present invention for each boom action before restriction;
FIG. 6 is a block diagram showing a configuration of a safety device for a boom working vehicle according to a second aspect of the present invention.
[Explanation of symbols]
1 High-altitude work vehicle (boom work vehicle)
10 body
30 boom
40 workbench
60 controller
61 Valve drive signal generator (boom operation control means, regulation means)
62 Valve drive (boom operation control means)
63 Falling moment calculation unit (falling moment detection means)
64 Judgment part (judgment means)
65 Regulatory Department (regulatory means)
66 Operation signal storage unit (boom motion detection means)
67 Boom motion detection unit (boom motion detection means)
71 Axial force detector (falling moment detection means)
V1-V3 control valve (boom operation control means)

Claims (2)

The car body,
A boom provided on the vehicle body so as to be undulating and telescopic;
Boom operation control means for performing control to raise or lower the boom according to an operation input from the outside;
A fall moment detecting means for detecting a fall moment acting on the vehicle body;
Determining means for determining whether or not the overturning moment detected by the overturning moment detecting means has reached a limit value;
Restricting means for prohibiting the boom operation control means from operating the boom in a direction in which the overturning moment exceeds the limit value when the determining means determines that the overturning moment has reached the limit value. In a safety device for a boom working vehicle having
A boom operation detecting means for detecting an operation of the boom immediately before the judgment by the judging means when the judging means judges that the overturning moment has reached the limit value;
The boom motion detecting means detects that the boom motion immediately before the judgment means judges that the overturning moment has reached the limit value is a rising motion that does not involve extension of the boom. If it is determined that the tip of the boom is caught or pressed against the structure, the restricting means determines that the overturning moment has reached the limit value by the determining means. safety device for a boom work vehicle that state is characterized by allowing if lodging operation without extension of the boom by previous SL boom operation control means ends until. The car body,
A boom provided on the vehicle body so as to be undulating and telescopic;
Boom operation control means for performing control to raise or lower the boom according to an operation input from the outside;
Load detecting means for detecting a load applied to the tip of the boom; and
Position detecting means for detecting the position of the tip of the boom with respect to the vehicle body;
It is determined whether or not the position of the tip of the boom detected by the position detection means has reached a limit position of an allowable movement range determined corresponding to the load load detected by the load detection means. Judgment means,
When the determination means determines that the position of the tip of the boom has reached the limit position of the allowable movement range, the position of the tip of the boom by the boom operation control means is the allowable value. A safety device for a boom working vehicle having a restricting means for prohibiting the operation of the boom in a direction deviating from a moving range,
When the determination means determines that the position of the tip of the boom has reached the limit position of the allowable movement range, the operation of the boom immediately before the determination by the determination means is detected. A boom operation detecting means;
The boom operation detection means does not involve the extension of the boom immediately before the determination means determines that the position of the tip of the boom has reached the limit position of the allowable movement range. When it is detected that the lifting operation has been performed, it is determined that the tip of the boom is caught or pressed against a structure, and the restricting means is configured to detect the tip of the boom by the determining means. that the state in which the position of the part is determined to have reached the limit position of the allowable movement range is acceptable as long as lodging operation without extension of the boom by previous SL boom operation control means ends until Boom working vehicle safety device.

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