JP2006151599A - Safety control device for working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safety control device for a working vehicle allowing a worker to easily determine whether the jack reaction force regulation type safety control device works normally or not. <P>SOLUTION: The safety control device for a working vehicle is structured of a reaction force detecting means 70, which is mounted on a working vehicle having a working device provided on a car body and a plurality of jacks for supporting the car body by grounding at a lower part thereof with extension of built-in hydraulic cylinders 64 and which detects corresponding grounding reaction force to be applied to the plurality of jacks, and an operation regulating means 92 for regulating operation of the working device when the grounding reaction force detected by the reaction force detecting means 70 lowers to the predetermined allowable grounding reaction force. Furthermore, the safety control device for a working vehicle is provided with a pressure detecting means 80 for detecting operating fluid pressure during the extending/shrinking operation of the hydraulic cylinders 64 and a pressure determining means 93 for determining whether the detected pressure detected by the pressure detecting means 80 exists within a proper pressure range or not when the predetermined grounding reaction force is detected by the reaction force detecting means 70. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a safety control device for a work vehicle including a jack that supports a traveling body by grounding a lower end portion.

  As a work vehicle equipped with the jack, for example, there is an aerial work vehicle. An aerial work platform consists of a traveling body equipped with a crawler device or tire wheels, etc., and a boom that can be swung, extended, retracted and raised, and a work table for operator boarding is attached to the end of the boom. Thus, it is possible to work on a work table moved to a desired height. When the boom is operated, the center of gravity of the vehicle moves and the vehicle becomes unstable, so that the lower end is grounded to the left and right sides of the traveling body, and the traveling body is lifted and supported. A jack is provided. Furthermore, there is a risk that the vehicle may fall over depending on the operating posture of the boom even if it is supported by a jack, and a safety device is provided that regulates the operation of the boom if a predetermined condition is met to avoid such danger. It is done.

  By grounding and supporting the traveling body by grounding the lower end portion of the jack, a corresponding grounding reaction force acts on each of the four jacks by lifting the traveling body in a stable support state. Here, as the safety device, for example, the ground reaction force acting on the jack is detected, and when the detected ground reaction force falls to a preset allowable ground reaction force, the operation of the work device such as a boom is regulated. (Jack reaction force regulation type).

In addition, as a means for detecting the ground reaction force provided in the jack reaction force regulation type safety device, the upper end of the hydraulic cylinder built in the jack is attached so as to allow the vertical movement, and the ground reaction force is reduced. Thus, means (for example, Patent Document 1) for detecting whether or not the allowable ground reaction force has been lowered by a limit switch that operates when the upper end of the hydraulic cylinder moves by a predetermined amount or more is provided.
Noto 2553246

  In such a jack reaction force regulation type regulation mode, the ground reaction force is detected for each of the four jacks, and the traveling body falls when the two adjacent ground reaction forces are reduced to the allowable ground reaction force. Some are configured to regulate the operation of the work equipment because of the high risk. In the safety control device having such a configuration, it is assumed that the ground reaction force detection means is normal. However, if even one of the four jacks has an abnormality in the detection means, the safety control device For example, the vehicle may fall over without restricting the operation of the work device. However, the limit switch used as a means for detecting the ground reaction force has an internal configuration such as a jack, and there is a problem that an operator cannot always easily determine an abnormality. For this reason, there exists a problem that abnormality may be overlooked and the vehicle may fall down.

  Further, in such a jack reaction force regulation type regulation form, it is necessary to set the allowable ground reaction force when the limit switch is operated to take a desired appropriate value, and this setting is performed appropriately. There is a high demand for a means for confirming whether or not there is a means for easily making an appropriate setting.

  In view of the above circumstances, an object of the present invention is to provide a safety control device for a work vehicle that allows an operator to easily determine whether or not a safety control device using a jack reaction force regulation type is functioning normally. .

  In order to achieve the above object, a safety control device for a work vehicle according to the present invention includes a traveling body, a working device provided on the traveling body, and a hydraulic cylinder provided on a side portion of the traveling body and incorporated therein (for example, an embodiment). The jack cylinder 64) is mounted on a work vehicle having a plurality of jacks that support the traveling body by extending the lower end of the jack cylinder 64), and the ground reaction force acting on the plurality of jacks corresponds to each of the plurality of jacks. The safety of a work vehicle comprising: a reaction force detecting means for detecting the operation force; and an operation restricting means for restricting the operation of the work device when the ground reaction force detected by the reaction force detecting means becomes a predetermined condition. In the control device, when a predetermined ground reaction force is detected by the pressure detection means for detecting the hydraulic pressure during the expansion / contraction operation of the hydraulic cylinder and the reaction force detection means during the expansion / contraction operation of the hydraulic cylinder. The pressure to be detected is constituted by a pressure determining means for determining whether or not within an appropriate pressure range which is predetermined based on a predetermined ground reaction force by the pressure detecting means.

  A safety control device according to the present invention is a jack reaction force regulation type safety control device that regulates the operation of a work device when the ground reaction force acting on the jack decreases to a preset allowable ground reaction force. Pressure detecting means for detecting the pressure of the hydraulic cylinder that is extended and retracted is provided, and whether or not the pressure detected by the pressure detecting means is within an appropriate pressure range when a predetermined ground reaction force is detected by the reaction force detecting means. A pressure determining means for determining is provided. Here, the appropriate pressure range is obtained corresponding to the ground reaction force, and if the pressure detected at the time of the predetermined ground reaction force action is not within the range determined based on the ground reaction force, It will be recognized that the reaction force detection means is abnormal and the correct ground reaction force is not detected. Therefore, by providing such a pressure detection means, it is possible to determine whether or not there is an abnormality in the reaction force detection means that is assumed to be normal when regulating the operation of the work device.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an aerial work vehicle 1 shown as an example of a work vehicle equipped with a safety control device according to the present invention. The aerial work vehicle 1 includes tire-type wheels 11, 11, a truck-type vehicle body 10 that can be driven and operated from a driving cabin 12, a work device 2 provided on the vehicle body 10, and a side portion of the vehicle body 10. The jacks 60, 60,. The work device 2 includes a swing body 20, a boom 30 whose base end portion is pivotally connected to a support bracket 29 provided so as to extend above the swing body 20, and an operator boarding work attached to the distal end portion of the boom 30. It is comprised from the stand 40 grade | etc.,.

  The swivel base 20 is attached to the rear portion of the vehicle body 10 so as to be rotatable about a vertical axis, and can be horizontally swiveled by hydraulically driving a swivel motor 21 built in the vehicle body 10. The boom 30 is configured by nesting a proximal boom 30a, an intermediate boom 30b, and a distal boom 30c. The boom 30 can be expanded and contracted by hydraulically driving an expansion / contraction cylinder 31 provided therein, The undulation cylinder 32 straddled between the base end boom 30a and the support bracket 29 can be undulated on the upper and lower surfaces by hydraulically driving. A vertical post 33 is attached to the tip of the tip boom 30c, and the vertical post 33 is always maintained in a vertical posture by a leveling device (not shown) regardless of the undulation angle of the boom 30.

  The work table 40 includes a box-like bucket 41 on which an operator boardes, a work table holding bracket 42 attached to the bucket 41, and the like. The work table holding bracket 42 is provided with a vertical post 33 and a vertical post 33. It is attached so that it can swing freely. A swing motor 43 is provided inside the worktable holding bracket 42, and the worktable 40 can be swung around the vertical post 33 by hydraulically driving the swing motor 43. Yes. As described above, since the vertical post 33 is always kept in the vertical posture, as a result, the floor surface of the bucket 41 is always kept horizontal.

  The bucket 41 is provided with an operation unit 50 for operating the swivel base 20, the boom 30, the work table 40, and the like. As shown in FIG. 2, the operation unit 50 is provided with a boom operation lever 51 for performing the swing operation, expansion / contraction operation, and raising / lowering operation of the boom 30, and a swing operation lever 52 for performing the swing operation of the work table 40. Thus, the boom 30 and the work table 40 can be operated so as to perform a desired operation by a lever tilting operation and a lever twisting operation in the directions indicated by the arrows. In the present embodiment, the base of the boom operation lever 51 is provided with a turning potentiometer 51a that detects a boom turning operation, an expansion / contraction potentiometer 51b that detects a boom expansion / contraction operation, and a hoisting potentiometer 51c that detects a boom raising / lowering operation. At the base of the swing operation lever 52, a swing potentiometer 52a for detecting the swing operation is provided. The swing operation lever 52 may be configured by providing a three-position switch at the base.

  In addition to the alarm buzzer 57 that emits an alarm sound, the alarm lamp 58 that is turned on at the time of warning, the operation unit 50 has an alarm buzzer 57 that emits an alarm sound. A display panel 59 capable of displaying the status is provided.

  Four jacks 60, 60,... Are provided on the side of the vehicle body 10 to support the vehicle in operation in a stable state. Each jack 60 includes an outer post 61 that extends in the vertical direction, an inner post 62 that is inserted into the outer post 61 so as to be extendable in the vertical direction, a jack pad 63 that is swingably attached to the lower end of the inner post 62, and the like. The inner post 62 can be expanded and contracted in the vertical direction by hydraulically driving a jack cylinder 64 straddled between the inner post 61 and the inner post 62, and the inner post 62 of each jack 60, 60,. Thus, the jack pad 63 can be grounded to support the vehicle body 10 in the lifted state. Moreover, each jack 60,60, ... is comprised so that extension to the side of the vehicle body 10 is possible, and the vehicle body 10 can be supported more stably now by the grounding in the state extended sideways. . The laterally extending and retracting operations of the jacks 60, 60,... And the inner posts 62, 62,... Are extended and retracted by operating the jack operating lever 13 provided at the rear portion of the vehicle body 10. Is called. The upper surface 61a of the outer post 61 is attached so as to be openable and closable.

  The internal structure of the jack 60 will be described with reference to a cross-sectional view of the outer post 61 shown in FIG. The jack cylinder 64 is held with respect to the outer post 61 by passing a holding pin 61a attached so as to be bridged between side plates facing each other in the outer post 61 in a holding hole 64b formed in the upper end portion of the cylinder tube 64a. Is done. The inner diameter of the holding hole 64b is set to be larger than the outer diameter of the holding pin 61a, and the jack cylinder 64 is held at the upper end with a backlash that allows the outer post 61 to move in the vertical direction. Will be.

  .. Are disposed inside the outer posts 61 of the jacks 60, 60,..., And the reaction force detecting device 70 is fixed to the outer post 61. A member 71, a movable member 72 attached so as to be movable in the vertical direction, a first reaction force detection switch 73 and a second reaction force detection switch 74 including limit switches, and an operation arm 75 for pushing the switches 73 and 74. Etc. The fixing member 71 is disposed above the cylinder tube 64 a of the jack cylinder 64 and is fixed to the outer post 61. Further, a through-hole 71 a penetrating vertically is formed at the center of the fixing member 71.

  The movable member 72 is disposed between the fixed member 71 and the upper end portion of the cylinder tube 64a, and is movably provided in the vertical direction while being urged downward by a double spring 76 disposed between the movable member 72 and the fixed member 71. ing. In addition, a through-hole 72a that penetrates vertically is formed in the center of the movable member 72, and a single stopper bolt 77 extends below the head portion of the through-hole 71a of the fixed member 71 and the through-hole 72a of the movable member 72. Has been inserted. A stopper nut 78 is fastened to the upper end of the stopper bolt 77, and below the fixed position of the movable member 72 urged downward by the double spring 76 due to the contact between the stopper nut 78 and the fixed member 71. Movement to is prevented.

  The first reaction force detection switch 73 is attached to the outer peripheral surface of the spring cover 71b that extends downward in a cylindrical shape from the lower surface of the fixing member 71, and turns on when the switch rod 73a is pushed upward to generate a detection signal. It consists of a limit switch that outputs and turns off when upward pushing is released. Similarly, the second reaction force detection switch 74 is attached to the outer peripheral surface of the spring cover 71b. When the switch rod 74a is pushed downward, it is turned on to output a detection signal, and the downward push is released. It consists of a limit switch that turns off.

  The operation arm 75 is integrally attached to the lower surface of the movable member 72 and moves up and down together with the movable member 72. The right end of the operation arm 75 extends to the lower side of the first reaction force detection switch 73, and a screw 75a is attached to the tip of the operation arm 75 so as to face the lower end of the switch rod 73a of the first reaction force detection switch 73. Yes. The left end of the operation arm 75 is bent and extends to above the second reaction force detection switch 74, and a screw 75b is provided at the tip of the operation arm 75 so as to face the upper end of the switch rod 74a of the second reaction force detection switch 74. It is attached.

  The jack 60 and the reaction force detection device 70 configured as described above are configured such that the upper end of the jack cylinder 64 is in a state where the vehicle body 10 is stably supported, that is, a sufficient ground reaction force is acting on the jack 60. Will move upward with respect to the holding pin 61a. Therefore, the operating arm 75 is positioned upward against the urging force of the double spring 76 along with the stopper nut 77 and the movable member 72, and the switch rod 73a of the first reaction force detection switch 73 is moved upward by the screw 75a. The first reaction force detection switch 73 is turned on to output a detection signal, and the switch rod 74a of the second reaction force detection switch 74 is detached from the screw 75b and turned off. When the jack 60 is not grounded, the upper end of the jack cylinder 64 moves downward with respect to the holding pin 61a. For this reason, the operating arm 75 is positioned downward along with the movable member 72 urged downward by the double spring 76, the switch rod 73a of the first reaction force detection switch 73 and the screw 75a are detached, and the first. The reaction force detection switch 73 is turned off, the switch rod 74a of the second reaction force detection switch 74 is pushed downward by the screw 75b, the second reaction force detection switch 74 is turned on, and a detection signal is output.

  The separation of the switch rod 73a and the screw 75a of the first reaction force detection switch 73 is set so as to be detached when the ground reaction force becomes a predetermined value (for example, 500 kg weight) or less. The switch rods 73a and 74a of the reaction force detection switch 73 and the second reaction force detection switch 74 are both configured to be separated from the screws 75a and 75b of the operation arm 75. The predetermined value of the ground reaction force can be changed by changing the set length of the double spring 76 that changes with the downward tightening length of the stopper nut 78 with respect to the stopper bolt 77. Further, an edge portion 79 edged by a marker or the like is provided at the upper end portion of the stopper bolt 77, and the upper end portion of the stopper bolt 78 can be visually recognized by opening the upper surface 61a of the outer post 61.

  FIG. 4 is a block diagram showing a configuration related to the controller 90 of the aerial work vehicle 1. The controller 90 is connected to the potentiometers 51 a to 51 c and 52 a and the detection switches 73 and 74, and detection signals from the respective potentiometers 51 a to 51 c and 52 a are output to the controller 90.

  Operation signals from the potentiometers 51a to 51c, 52a, and 13a provided on the levers 51 and 52 of the operation unit 50 and the jack operation lever 13 at the rear of the vehicle body 10 are output to the valve control unit 91 of the controller 90, respectively. It has become. The valve controller 91 electromagnetically drives the first control valve V1 corresponding to the turning motor 21 based on the turning operation signal from the turning potentiometer 51a, and corresponds to the raising / lowering cylinder 32 based on the raising / lowering operation signal from the raising / lowering potentiometer 51b. The second control valve V2 is electromagnetically driven, and the third control valve V3 corresponding to the expansion / contraction cylinder 31 is electromagnetically driven based on a turning operation signal from the expansion / contraction potentiometer 51c. The fourth control valve V4 corresponding to the swing motor 43 is electromagnetically driven based on the swing operation signal from the swing potentiometer 52a, and the jack cylinder 64 is based on the jack operation signal from the jack potentiometer 13a. The fifth control valve V5 corresponding to is configured to be electromagnetically driven.

  The hydraulic fluid discharged from the hydraulic pump P provided in the vehicle body 10 is supplied to the hydraulic actuators 21, 31, 32, 43, and 64 via the first to fifth control valves V1 to V5. Thus, the boom 30, the work table 40, and the jack 60 are operated according to the lever operation of the operator.

  Further, the pressure of the hydraulic oil supplied to the jack cylinder 64 of each jack 60, 60,... Is detected by the pressure sensor 81. Hereinafter, the pressure sensor 81 together with the hydraulic circuit configuration of the jack cylinder 64 will be described. Briefly described. Here, the jack cylinder 64 is a double-acting cylinder as shown in the figure, and has two ports, a tube side port 641 and a rod side port 642.

  The hydraulic circuit for driving the jacks 60, 60,... Is driven by a fifth control valve V5 that operates according to the lever operation of the jack operation lever 13 provided corresponding to each jack 60. It is configured to be able to switch which port of the jack cylinder 64 is supplied. The fifth control valve V5 is provided corresponding to each of the jack cylinders 64 of the jacks 60, 60,. The jack cylinder 64 moves up and down the jack 60 by switching the port. If hydraulic pressure is supplied to the tube side port 641, the cylinder rod 64c extends to operate the jack 60 in the grounding direction. If hydraulic pressure is supplied to the rod side port, the cylinder rod 64c is contracted to operate the jack 60 in the retracted direction. A double pilot check valve PCV (hereinafter also referred to as a check valve PCV) is attached to each port of the jack cylinder 64 in order to prevent the vehicle body from tilting due to hydraulic leakage when the jack operation is stopped. And the pressure sensor 81 is provided in the oil path L1 which connects the 5th control valve V5 and the tube side port in the hydraulic pump P side with respect to this check valve PCV, and hydraulic oil flows through the oil path L1. In this state, the hydraulic pressure supplied to the tube side port can be detected. Such a pressure sensor 81 is provided corresponding to each of the jack cylinders 64, 64,.

  , Detection signals from the first reaction force detection switch 73 and the second reaction force detection switch 74 of the reaction force detection devices 70, 70,... Provided in each jack 60, 60,. It is output. When the first reaction force detection switch 73 is turned on and the detection signal is output, the operation restricting portion 92 is assumed that the vehicle body 10 is stably supported by the four jacks 60, 60,. Control is performed so that the boom 30 can be continuously operated. Here, if the first reaction force detection switch 73 provided in two adjacent jacks 60, 60 among the pressure detection switches 71 provided in the jacks 60, 60,... Is turned off, the jacks 60, 60,. , The boom operation restriction signal is output to the valve control unit 91 assuming that the stable support by the jacks 60, 60,... Is not performed.

  When the boom operation restriction signal is output to the valve control unit 91 by the operation restriction unit 92, the valve control unit 91 operates in a direction in which the overturning moment acting on the boom 30 increases in the operation of the boom 30 ( Even if an operation signal for operating in such a direction from the telescopic potentiometer 51b and the hoisting potentiometer 51c of the boom operation lever 51 is output to the valve control unit 91, it is based on this signal. The second and third control valves V2 and V3 are not electromagnetically driven. By restricting the operating direction of the boom 30 in this way, the vehicle can be prevented from tipping over.

  Also, an alarm buzzer 57, an alarm lamp 58, and a display panel 59 provided in the operation unit 50 are connected to the controller 90, and in synchronization with the boom operation restriction signal output from the operation restriction unit 92 to the valve control unit 91. It comes to work. Accordingly, it is possible to notify the operator who operates both levers 51 and 52 that the operation restriction of the boom 30 has been performed. The display panel 59 can display which jack 60's ground reaction force has fallen to an allowable ground reaction force.

  The controller 90 configured to include such an operation regulating unit 92 is provided with a determination unit 93 and a storage unit 94 for performing control for performing abnormality determination based on the pressure value detected by the pressure sensor 81. Yes. Hereinafter, control of abnormality determination performed in the determination unit 93 will be described.

  Assume that an operation of extending the inner post 62 from the retracted posture and grounding the jack 60 is performed. First, it is confirmed whether or not the upper surface of the outer post 61 is opened and the stopper nut 78 is tightened to the vicinity of the edge portion 79 provided on the stopper bolt 77. Here, when the stopper nut 78 is not tightened to the rim 79, or when tightening is excessive, the tightening amount is adjusted respectively.

  Until the inner post 62 extends and the jack pad 63 is grounded, the second reaction force detection switch 74 is on and a detection signal is output to the operation restricting portion 92. When the jack pad 63 is grounded, the upper end of the jack cylinder 64 is moved upward, the second reaction force detection switch 74 and the screw 75b are detached, the second reaction force detection switch 74 is turned off, and the ground reaction force is applied to the jack 60. Will act. When this grounding reaction force reaches a preset allowable grounding reaction force, the first reaction force detection switch 73 is pressed by the screw 75a to be turned on, and a detection signal is output to the operation restricting portion 92. Become.

  In the reaction force detection device 70 of any jack 60, the first reaction force detection switch 73 is turned on when the first reaction force detection switch 73 and the second reaction force detection switch 74 are both turned off. When the detection signal is output to the operation restricting unit 92, the pressure of the oil supplied to the jack cylinder 64 detected by the pressure sensor 81 of the pressure detecting device 80 of the jack 60 corresponding to the determining unit 93 is output and detected. A determination is made as to whether or not the pressure is within the appropriate pressure range read from the storage unit 94. Here, the appropriate pressure range is generally determined according to the ground reaction force acting on the jack 60. In the present embodiment, the proper pressure range acts on the jack 60 when the first reaction force detection switch 73 is turned on. An appropriate pressure range corresponding to when the ground reaction force is an allowable ground reaction force is stored.

  When the pressure detected by the pressure sensor 81 is within the appropriate pressure range, the reaction force detection device 70 is recognized to be normal, and the reaction force detection device 70 together with the pressure value detected by the display panel 59. Is displayed indicating that is normal.

  When the pressure detected by the pressure sensor 81 is not within the appropriate pressure range, it is recognized that the reaction force detection device 70 provided in the jack 60 corresponding thereto has an abnormality. At this time, on the display panel 59, a display indicating that the reaction force detection device 70 is abnormal together with the detected pressure value is made, and in synchronization with a warning display on the display panel 59, As with the display panel 59, the alarm buzzer 57 and the alarm lamp 58 connected to the controller 90 are actuated to emit an alarm and to turn on an alarm.

  According to the configuration of the present embodiment, the pressure detection for detecting the pressure of the jack cylinder 64 in the aerial work vehicle 1 in which safety control is performed by the jack reaction force regulation configured using the reaction force detection device 70. The apparatus 80 is provided, and the determination unit 93 determines whether or not the pressure detected by the pressure detection device 80 is within an appropriate pressure range stored in the storage unit 94 in advance, and the determination result is notified by the display panel 57 or the like. It is configured. Accordingly, the determination unit 92 determines whether or not the reaction force detection device 70 needs to be normal in order to regulate the operation of the boom 30, and the determination result is notified to the operator by the display panel 59 or the like. Will be able to. As a result, when it is determined that the detected pressure is within the appropriate pressure range and is normal, the operator can again recognize that the reaction force detector 70 is operating normally. Is not within the appropriate pressure range, and it is determined that the reaction force detection device 70 is abnormal, this is not overlooked and the response to the abnormality can be speeded up and the vehicle can be prevented from falling over. Can be carried out effectively.

  Further, such abnormality determination control is performed when a predetermined ground reaction force is detected, for example, in the present embodiment, when the jack 60 is extended, that is, before the work at a high place using the work device 2 is performed. Yes. As a result, it is possible to notify the operator of this abnormality before starting the work, prompt the worker to perform a safe work with the abnormality in mind, and more effectively prevent the vehicle from falling over. Can do.

  Furthermore, the detected pressure value can be displayed. For this reason, when it is determined that an abnormality has occurred, it is possible to take a response to the abnormality of the reaction force detection device with reference to the displayed pressure value, and to promptly deal with the abnormality. be able to.

  Further, the reaction force detection device 70 of the present embodiment has a grounding reaction that acts on the jack 60 when the first detection switch 73 is operated in a state where the stopper nut 78 is tightened to the edge 79 provided on the stopper bolt 77. An edge 79 is provided so that the force is set to an appropriate ground reaction force. The upper surface 61a of the outer post 61 is attached so as to be openable and closable, and the stopper nut 78 and the edge portion 79 can be visually recognized by opening the upper surface 61a. Thereby, it is possible to confirm whether or not the setting of the allowable grounding reaction force used as a threshold value for regulating the operation of the boom 30 with the edging portion 79 as a mark is appropriate. It is possible to easily determine whether the abnormality of the reaction force detection device 80 is caused by the setting of the allowable grounding reaction force being inappropriate, and the stopper nut 78 is tightened with reference to the edge 79. By doing so, an appropriate setting of the allowable setting reaction force can be easily performed.

  The appropriate pressure range is generally determined according to the ground reaction force. In this embodiment, the ground reaction force assumed when setting and storing the proper pressure range in the storage unit 94 is the first reaction force. This is an allowable ground reaction force that turns on the detection switch 73. For this reason, it is ensured that the first reaction force detection switch 73 operates according to the action of the grounding reaction force as expected, as described above, by tightening the stopper nut 78 to the edge portion 79. In addition to this, it is possible to ensure the accuracy of the abnormality determination control by comparing the pressure detected at this time with the appropriate pressure range. In addition, after an abnormality is determined, a quick response with reference to the border 79 can be taken.

  In the above embodiment, the pressure sensor 81 detects the pressure when the ground reaction force acting during the expansion / contraction operation of the jack reaches the allowable ground reaction force, and compares it with the appropriate pressure range stored in advance. However, it is not necessarily limited to this, it constitutes a limit switch that operates according to a predetermined ground reaction force different from the allowable ground reaction force, and the appropriate pressure according to this ground reaction force is stored in the storage unit, This can be similarly implemented by obtaining a comparison between the pressure detected by the pressure sensor 81 when the limit switch is operated and the appropriate pressure stored in the storage unit 94, and the same effect can be obtained. Further, this abnormality determination is not limited to when the jack 60 is extended, and the pressure detected by the pressure sensor 81 and the appropriate pressure stored in the storage unit 94 are similarly detected even when the predetermined ground reaction force is reduced. By carrying out the comparison judgment with the range, it can be similarly implemented and the same effect can be obtained.

  Further, the pressure sensor 81 is individually provided on the fifth control valve V5 side with respect to the check valve PCV provided in the jack cylinder 64 of each jack 60, 60,... (That is, four pressure sensors 81, 81,...). However, the present invention is not necessarily limited to this, and any structure may be used as long as it does not cause a hydraulic leak of the jack cylinder 64 when the operation is stopped. For example, instead of the four pressure sensors 81, 81,... Provided in the vicinity of each jack cylinder 64, 64,..., One pressure sensor 81p is represented in the pump line Lp as shown by a broken line in FIG. It is good also as a structure provided. The hydraulic pressure during the expansion / contraction operation in the jack cylinder 64 is affected by pressure loss or the like until the hydraulic pressure is supplied from the hydraulic pump P to the jack cylinder 64, and therefore, is different from the pressure detected in the pump line Lp. The difference amount (decrease amount) has an individual difference in each jack cylinder 64, 64,. For this reason, in the case of a configuration represented by the pressure sensor 81p provided in the pump line Lp, the pressure detected by the pressure sensor 81p when a predetermined ground reaction force is detected in each jack 60, 60,. The operating pressure in the jack cylinder 64 in which the predetermined ground reaction force is detected is corrected and calculated in the determining unit 93 in consideration of the reduction amount and the individual difference, and the corrected detected pressure is stored in the storage unit 94. By determining whether or not the pressure is within the stored appropriate pressure range, it can be implemented in the same manner as in the above-described embodiment, and the same effect can be obtained. Moreover, according to such a structure, since the installation quantity of the pressure sensor 81 can be decreased, the safety control apparatus of the working vehicle which concerns on this invention can be comprised simply.

  In the above-described embodiment, the safety control device according to the present invention is configured to have only a jack reaction force regulation type regulation form, but has a jack reaction force regulation type regulation form. A mode in which the applied overturning moment is sequentially detected and the operation of the boom 30 is regulated when the detected overturning moment reaches a preset allowable overturning moment, or the position of the work table 40 is sequentially detected, and preset allowable work is performed. The operation control of the boom 30 is controlled by two control modes, together with the mode of controlling the operation of the boom 30 when the detection position of the work table 40 reaches the limit of the allowable work range set in advance within the range. It may be configured. Even in the safety control device configured as described above, it is possible to obtain the same effect by performing the control performed by the operation restriction unit, and the operation restriction or work performed by detecting the overturning moment. Even if the operation regulation performed by detecting the position of the base 40 is abnormal, the operator can confirm whether or not the jack reaction force regulation type control device is functioning normally. It is possible to prevent falls.

  Further, as an example of the work vehicle equipped with the safety control device according to the present invention, the aerial work vehicle 1 in the form of providing the jacks 60, 60,... Can be similarly applied to a working vehicle in which jacks are provided at two positions on the left and right sides of the vehicle body 10 or a working vehicle in which jacks are provided at five positions on the front part of the vehicle body and front, rear, left and right. Can be obtained.

  In addition, as an example of a work vehicle equipped with the safety control device according to the present invention, a boom 30 and a work table 40 that can turn, extend and retract, and have a work table 40 based on a vehicle body 10 having tire wheels 11, 11,. However, as long as the work vehicle is configured with a jack, the vehicle body 10 may be based on, for example, a vehicle equipped with a crawler device. A crane device or the like may be mounted, which can be implemented in the same manner and can obtain the same effect.

It is a perspective view of an aerial work vehicle shown as an example of a work vehicle equipped with a safety control device according to the present invention. It is a perspective view which shows the operation part of the said aerial work vehicle. It is sectional drawing of the outer post of the aerial work vehicle. It is a block diagram which shows the structure which concerns on the controller with which the said aerial work vehicle is equipped.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High-altitude work vehicle 2 Working apparatus 10 Traveling body 20 Swivel base 30 Boom 40 Working base 50 Operation part 57 Alarm buzzer 58 Alarm lamp 59 Display panel 60 Jack 61 Outer post 62 Inner post 63 Jack pad 64 Jack cylinder 70 Reaction force detection apparatus 73 , 74 Reaction force detection switch 80 Pressure detection device 81 Pressure sensor 90 Controller 91 Valve control unit 92 Operation regulation unit 93 Judgment unit 94 Storage unit

Claims (1)

A traveling body, a working device provided on the traveling body, and a plurality of jacks that are provided on a side portion of the traveling body and support the traveling body by grounding a lower end by an extension operation of a built-in hydraulic cylinder. Mounted on a working vehicle having
Reaction force detection means for detecting a ground reaction force acting on the plurality of jacks corresponding to each of the plurality of jacks;
In a safety control device for a work vehicle configured to include operation restriction means for restricting the operation of the work device when a ground reaction force detected by the reaction force detection means becomes a predetermined condition,
Pressure detecting means for detecting the hydraulic pressure during expansion and contraction of the hydraulic cylinder;
When a predetermined ground reaction force is detected by the reaction force detection means during the expansion and contraction operation of the hydraulic cylinder, the pressure detected by the pressure detection means is determined in advance based on the predetermined ground reaction force. A safety control device for a work vehicle, comprising: pressure determination means for determining whether or not the pressure is within a pressure range.

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