JP6507790B2 - Work vehicle - Google Patents

Description

  The present invention relates to a work vehicle capable of simultaneously performing turning of a turning body and raising and lowering of a boom.

  BACKGROUND ART A crane vehicle is conventionally known that includes a lower traveling body, an upper swing body rotatably supported by the lower running body, and a boom supported by the upper swing body so as to be able to move up and down (for example, Patent Document 1) , See 2). In addition, in the crane vehicle described in Patent Documents 1 and 2, for example, in order to prevent the crane vehicle from tipping over or to prevent contact with an obstacle, a work limit area and a turning gentle stop area are set. There is.

  The work limit area is an area where entry of the tip of the boom is prohibited. The swing slow stop region is a region that gradually reduces the swing speed of the upper swing body so that the tip end of the boom does not enter the work limit region. Then, when the tip of the boom enters the turning gentle stop area during turning of the upper turning body, the crane vehicle gradually reduces the turning speed so that turning of the upper turning body stops before the working limit area ( Hereinafter, it is described as "slow stop."

Japanese Patent Application Laid-Open No. 11-139771 Patent No. 3252007

  However, the above-mentioned gentle stop control presupposes that the turning of the upper structure is performed alone. Therefore, when the swing of the upper swing body and the fall of the boom are simultaneously performed, it may be necessary to stop the swing or the fall suddenly. As a result, the hanging load may swing significantly or damage to the boom may occur.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a tip end of the boom without rapidly stopping the turning and the falling even when the turning of the turning body and the falling of the boom are simultaneously performed. An object of the present invention is to provide a work vehicle capable of suppressing entry into the work limit area.

  (1) A working vehicle according to the present invention includes: a traveling body; a swing body rotatably supported by the traveling body; a boom supported by the swing body so as to be able to be raised and lowered; and a swing actuator pivoting the swing body A hoisting actuator for hoisting the boom, a first operation unit for receiving an operation for instructing the turning of the swing body, a second operation unit for receiving an operation for instructing the falling of the boom, and a control unit. The control unit causes the turning actuator to turn the turning body and causes the turning actuator to turn the boom in response to simultaneous operation of the first operation unit and the second operation unit. And a first determination process for determining a limit line indicating the boundary of the workable area in which the entry of the tip of the boom is permitted and the work limit area in which the approach is prohibited; At least one of the swing actuator and the relief actuator in accordance with the second determination process of determining the restricted area for restricting the swing-down process and the tip of the boom entering the restricted area by the swing-down process. Perform a slow stop process to make a slow stop. The control unit is the limit line indicating the boundary of the work limit area where the approach of the tip of the fallen boom is prohibited in the first determination process, and the control unit is an arc having a first radius. (1) A second falling limit line of a second radius adjacent to the first falling limit line in the turning direction and smaller than the first radius in the turning direction, and entry of the tip of the boom by turning of the turning body is prohibited The limit line indicating the boundary of the work limit area, and a turning limit line connecting the adjacent ends of the first and second lodging limit lines is determined. In the determination process, an intersection point of the second falling limit line and the turning limit line is one of apexes, an extension line of a predetermined length of the second falling limit line is a first contour line, and the turning limit line is Let extension line of predetermined length be the second outline The shape region is determined as the restriction region, and in the slow stop processing, the extension line of the movement trajectory of the tip of the boom moved by the swing and lodging processing intersects the first outline. The pivoting actuator is gently stopped so that the tip of the boom stops at the pivot limit line, and the tip of the boom is inclined at the second position in response to the extension of the movement locus intersecting the second outline. The relief actuator is gently stopped to stop at the limit line.

  According to the above configuration, one of the swing actuator and the relief actuator is loosely stopped according to the positional relationship between the extension line of the movement trajectory of the tip of the boom and the restriction area. And since the above-mentioned judgment is performed at the timing in which the tip of the boom entered into the control area, it is possible to secure the distance necessary for the slow stop of the actuator. As a result, it is possible to suppress the tip end of the boom from entering the working limit area without stopping the turning and falling suddenly.

  (2) Preferably, in the slow stop process, the control unit causes the swing actuator to stop at the intersection of the tip of the boom in response to the extension line of the movement trajectory passing through the intersection. And gently stop the relief actuator.

  According to the above configuration, it is possible to prevent the tip end of the boom from entering the work limit area through the intersection of the second fall limit line and the turning limit line.

  (3) Preferably, in the second determination process, the control unit lengthens the first outline as the turning speed of the swing body increases, and the control unit adjusts the second outline as the falling speed of the boom increases. Lengthen.

  According to the above-mentioned configuration, it is possible to secure a distance necessary to safely and gently stop the turning of the turning body and the falling of the boom.

  (4) As an example, in the first determination process, the control unit extends side by side with the first displacement limit line on the workable area side from the first displacement limit line, and stops the boom from relaxing slowly. A first lodging loose stop line indicating the border of the lodging loose stop area and a second lodging limit line extending along the workable area from the second lodging limit line, and a border indicating the border of the lodging loose stop area (2) a loose suspension stop line and a swing loose stop line extending along the swing limit line on the workable area side from the swing limit line and indicating the boundary of the swing loose stop region for slow stop of the swing of the swing body decide. Then, in the second determination process, the control unit performs the first outline, the second outline, and a third outline that is an extension of a predetermined length of the second loose relaxation stop line The figure area surrounded by the fourth outline, which is an extension line of the predetermined length of the turning loose stop line, is determined as the restriction area.

  (5) As another example, in the second determination process, the control unit performs an arc-shaped third contour having a third radius centered on the intersection point with the first contour line, the second contour line, and the intersection point. The figure area surrounded by the line is determined as the restriction area.

  According to the present invention, at the timing when the tip of the boom enters the control area, at least one of the swing actuator and the relief actuator is gently stopped according to the positional relationship between the extension line of the movement trajectory of the tip of the boom and the control area. Therefore, it is possible to prevent the tip of the boom from entering the working limit area without stopping the turning and the fall.

FIG. 1 is a schematic view of a rough terrain crane 10 according to the present embodiment. FIG. 2 is a functional block diagram of the rough terrain crane 10. FIG. 3 is a flowchart of the operation control process. FIG. 4 is a flowchart of the slow stop process. FIG. 5 is a diagram showing an example of limit lines 61 to 64 and slow stop lines 66 to 69. In FIG. FIG. 6 is a diagram showing an example of a control area in the present embodiment. FIG. 7 is a view showing the relationship between extension lines 71 ′ to 73 ′ of movement trajectories 71 to 73 of the tip of the telescopic boom 32 and the restriction area.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as appropriate. It is needless to say that the present embodiment is only one aspect of the present invention, and the embodiment may be modified without departing from the scope of the present invention.

[Rough terrain crane 10]
The rough terrain crane 10 according to the present embodiment mainly includes a lower traveling body 20 and an upper revolving body 30, as shown in FIG. The rough terrain crane 10 is an example of a work vehicle. However, the specific example of the work vehicle is not limited to the rough terrain crane 10, and may be, for example, an all terrain crane, a cargo crane, a work at a high place, or the like.

[Lower traveling body 20]
The lower traveling body 20 has a pair of left and right front wheels 21 and a pair of left and right rear wheels 22 (in FIG. 1, only the right side is shown). The front wheel 21 and the rear wheel 22 are rotated by the driving force of an engine (not shown) transmitted through a transmission (not shown). The lower traveling body 20 travels by the operator operating a steering wheel, an accelerator pedal, a brake pedal and the like installed in a cabin 34 described later.

  The lower traveling body 20 also has a pair of left and right outriggers 23 provided on the front side of the lower traveling body 20 and a pair of left and right outriggers 24 provided on the rear side of the lower traveling body 20 (in FIG. 1) Only the right side is shown). The outriggers 23 and 24 can be changed between an extended state in which the ground contacts the ground at a position protruding in the left and right direction from the lower traveling body 20 and a stored state stored in the lower traveling body 20 while separated from the ground is there.

  The attitude of the rough terrain crane 10 is stabilized by bringing the outriggers 23 and 24 into the overhanging state when the upper swing body 30 is in operation. On the other hand, the outriggers 23 and 24 are stored when the lower traveling body 20 travels. Moreover, the rough terrain crane 10 can make the overhang | projection amount of the outriggers 23 and 24 differ by right and left. In the example of FIG. 5, the overhanging amount of the outriggers 23 and 24 on the right side is smaller than the overhanging amount of the outriggers 23 and 24 on the left side.

[Upper swing body 30]
The upper swing body 30 is swingably supported by the lower traveling body 20 via a swing bearing (not shown). The upper swing body 30 is swung by a swing motor 31 (see FIG. 2). The swing motor 31 is an example of a swing actuator. Further, as shown in FIG. 1, the upper swing body 30 mainly includes the telescopic boom 32, the hooks 33, and the cabin 34.

  The telescopic boom 32 is supported by the upper rotating body 30 so as to be able to move up and down. The telescopic boom 32 is raised and lowered by a raising and lowering cylinder 35 and is expanded and contracted by a telescopic cylinder 36 (see FIG. 2). The telescopic boom 32 is not limited to a box-type boom, and may be a lattice jib. The relief cylinder 35 is an example of a relief actuator. The hooks 33 are suspended on a rope 38 extended downward from the tip of the telescopic boom 32. The hooks 33 are raised and lowered by winding and feeding the rope 38 by a winch 39 (see FIG. 2). Furthermore, the cabin 34 has an operation unit 56 (see FIG. 2) for operating the lower traveling body 20 and the upper swing body 30.

[Control unit 50]
The rough telelane crane 10 includes a control unit 50 as shown in FIG. The control unit 50 controls the operation of the rough terrain crane 10. The control unit 50 may be realized by a CPU (Central Processing Unit) that executes a program stored in the memory, may be realized by a hardware circuit, or a combination of these.

  As shown in FIG. 2, the control unit 50 acquires various signals output from the turning angle sensor 51, the elevation angle sensor 52, the boom length sensor 53, the suspension load sensor 54, the outrigger sensor 55, and the operation unit 56. Do. Further, the control unit 50 controls the swing motor 31, the relief cylinder 35, the extension cylinder 36, the winch 39, and the outriggers 23 and 24 based on the acquired various signals.

  The swing angle sensor 51 outputs a detection signal according to the swing angle of the upper swing body 30 (for example, the angle in the clockwise direction with the forward direction of the lower traveling vehicle 20 set to 0 °). The elevation angle sensor 52 outputs a detection signal according to the elevation angle of the telescopic boom 32 (the angle between the horizontal direction and the telescopic boom 32). The boom length sensor 53 outputs a detection signal according to the length of the telescopic boom 32. The hanging load sensor 54 outputs a detection signal according to the weight of the hanging load 40 hung on the hook 33. The outrigger sensor 55 outputs a detection signal according to the state of the outriggers 23 and 24 and the overhang amount.

  The operation unit 56 receives an operation of a user for operating the rough terrain crane 10. Then, the operation unit 56 outputs an operation signal according to the received user operation. That is, based on the user's operation received through the operation unit 56, the control unit 50 causes the lower traveling unit 20 to travel and causes the upper swinging unit 30 to operate. The operation unit 56 includes a lever for operating the rough terrain crane 10, a steering, a pedal, an operation panel, and the like.

  The operation unit 56 according to the present embodiment includes a swing lever that drives the swing motor 31 and a raising and lowering lever that drives the raising and lowering cylinder 35. The user can turn the upper swing body 30 by operating the turning lever, and can raise and lower the telescopic boom 32 by operating the raising and lowering lever. The swing lever is an example of a first operation unit that receives an operation for instructing the swing of the upper swing body 30. The hoisting lever is an example of a second operation unit that receives an operation to instruct the telescopic boom 32 to fall.

  The control unit 50, for example, specifies the turning direction according to the direction in which the turning lever is falling, and specifies the turning speed according to the amount of movement of the turning lever. Then, the control unit 50 drives the swing motor 31 so that the upper swing body 30 is turned at the swing speed specified in the specified swing direction. Further, for example, the control unit 50 specifies the direction of ups and downs (raising or falling) in accordance with the direction of movement of the ups and downs, and specifies the rate of ups and downs according to the amount of movement of the ups and downs. Then, the control unit 50 drives the relief cylinder 35 such that the telescopic boom 32 is undulated at the relief speed specified in the specified relief direction. In addition, according to operation of the control lever of each above-mentioned turning, raising and lowering, a turning motor and a raising and lowering cylinder may be driven, and speed may be specified by each amount of angle change.

  Further, the swing motor 31, the relief cylinder 35, the extension cylinder 36, and the winch 39 according to the present embodiment are hydraulic actuators. That is, the control unit 50 drives each actuator by controlling the direction and flow rate of the supplied hydraulic oil. However, the actuator of the present invention is not limited to the hydraulic type, and may be an electric type or the like.

[Operation of rough terrain crane 10]
Next, the operation of the rough terrain crane 10 will be described with reference to FIGS. 3 to 7. The control unit 50 starts the operation control process shown in FIG. 3 in response to, for example, the operation signal being output from both the turning lever and the raising and lowering lever. The user can operate both the turning lever and the raising and lowering lever at the same time (hereinafter referred to as "combination operation"). In the present specification, the processing in the case where only one of the turning lever and the raising and lowering lever is operated alone (hereinafter referred to as "single operation") is omitted. Further, in the present specification, the process in which the telescopic boom 32 is raised and lowered, and the process in which the telescopic boom 32 is expanded and contracted are omitted.

  First, the control unit 50 executes a first determination process (S11). The first determination process is a process of determining a limit line indicating the boundary of the workable area and the work limit area, and a slow stop line indicating the boundary of the slow stop area. The workable area is an area where entry of the tip of the telescopic boom 32 is permitted. The work limit area is an area in which the approach of the tip of the telescopic boom 32 is prohibited. The loose stop area is an area in which the operation of the upper swing body 30 or the telescopic boom 32 is made to gently stop. The workable area, the work limit area, the gradual stop area, and the restriction area described later are virtual areas on the horizontal plane including the rough terrain crane 10.

  The limit line includes, as shown in FIG. 5, lodging limit lines 61 and 62 and turning limit lines 63 and 64. The lodging limit lines 61, 62 indicate the boundaries of the working limit area in which the entering of the telescopic boom 32 which has been lodged is prohibited. The turning limit lines 63 and 64 indicate the boundaries of the working limit area in which the entry of the telescopic boom 32 by the turning of the upper swing body 30 is prohibited. In addition, the slow stop lines include falling slow stop lines 66, 67 and turning slow stop lines 68, 69. Falling loose stop lines 66, 67 indicate the boundaries of the falling loose stop area where the falling of the telescopic boom 32 is gently stopped. The swinging loose stop lines 68, 69 indicate the boundaries of the swinging loose stop area where the swing of the upper swing body 30 is stopped gently. The limit line and the slow stop line are imaginary lines on the horizontal plane including the rough terrain crane 10.

The control unit 50 determines the lodging limit lines 61, 62 based on, for example, the amount of overhang of the outriggers 23, 24, the weight of the hanging load 40, and the like. Lodging limit line 61 is a circular arc shape of radius R ₁ centered on the rotation center of the upper rotating body 30. The lodging limit line 62 is an arc having a radius R ₂ (<R ₁ ) centered on the turning center of the upper swing body 30. In addition, the lodging limit lines 61 and 62 are adjacent to each other in the turning direction of the upper swing body 30. The lodging limit line 61 is an example of a first lodging limit line, the lodging limit line 62 is an example of a second lodging limit line, the radius R ₁ is an example of a first radius, and the radius R ₂ is a second radius. It is an example.

Then, in the example of FIG. 5, the control unit 50 arranges the slope limit lines 61 in front of, to the left and to the rear of the rough terrain crane 10, and the right overhang of the rough terrain crane 10 is small. Arrange the fall limit line 62 in the direction. The control unit 50 includes, for example, set to a small enough radius _R 1, _{R 2} overhang of the outriggers 23 and 24 is small, setting a small radius _R 1, _{R 2} as the weight of the suspended load 40 is large.

  Next, the control unit 50 determines turning limit lines 63, 64 connecting the adjacent ends of the falling limit lines 61, 62. In the example of FIG. 5, the turning limit line 63 is a part of a straight line passing through the turning center of the upper swing body 30 and extending diagonally forward to the right of the rough terrain crane 10. Further, the turning limit line 64 is a part of a straight line passing through the turning center of the upper swing body 30 and extending diagonally rearward to the right of the rough terrain crane 10.

Next, the control unit 50 determines the falling slope stop lines 66 and 67 based on, for example, the falling speed of the telescopic boom 32 or the like. The falling relaxation stop lines 66, 67 extend parallel to the falling limit lines 61, 62 on the working area side of the falling limit lines 61, 62. In the example of FIG. 5, the falling gentle stop line 66 is an arc having a radius R ₃ (<R ₁ ) centered on the turning center of the upper swing body 30. The falling loose stop line 67 is an arc having a radius R ₄ (<R ₂ ) centered on the turning center of the upper swing body 30.

  Note that “two lines extend side by side” means that the distance between the two lines hardly changes depending on the place. Typically, two lines are "parallel" if they are straight and concentric if they are arcs, but they need not be strictly parallel or concentric arcs. That is, as shown in FIG. 5, it means that the lodging limit lines 61, 62 and the laid loose stop lines 66, 67 extend in substantially the same direction without crossing each other. The same applies to the relationship between the turning limit lines 63 and 64 and the turning gentle stop lines 68 and 69 described later.

Next, the control unit 50 determines the swing loose stop lines 68 and 69 based on, for example, the swing speed of the upper swing body 30 and the like. The swinging loose stop lines 68, 69 extend parallel to the swing limit lines 63, 64 on the workable area side of the swing limit lines 63, 64. In the example of FIG. 5, the turning slow stop line 68 passes through the rotation center of the upper rotating body 30, the inclination angle theta ₁ inclined by linearly from turning limit line 63 in the counterclockwise direction. The swinging loose stop line 69 is a straight line passing through the swinging center of the upper swing body 30 and being inclined clockwise by a tilt angle θ ₂ from the swing limit line 64.

The control unit 50 reduces the radii R ₃ and R ₄ as the lodging speed of the telescopic boom 32 is faster. Alternatively, the control unit 50 may determine the radii R ₃ and R ₄ based on the maximum falling speed of the telescopic boom 32. Similarly, the control unit 50 increases the tilt angles θ ₁ and θ ₂ as the swing speed of the upper swing body 30 increases. Alternatively, the control unit 50 may determine the inclination angles θ ₁ and θ ₂ based on the maximum pivoting speed of the upper swing body 30.

  As a result, the area surrounded by the lodging limit lines 61 and 62 and the turning limit lines 63 and 64 becomes the workable area. Moreover, the area | region of the fall limit line 61,62 and the outer side of the turning limit line 63,64 turns into a working limit area. Also, an area surrounded by the falling limit line 61, the falling loose stop line 66, and the turning limit lines 63 and 64, and an extension of the falling limit line 62, the falling loose stop line 67 and the turning limit lines 63 and 64. The falling area is the falling relaxation stop area. Further, an area surrounded by the turning limit line 63, the turning loose stop line 68, the falling limit line 61, and the extension of the falling limit line 62, the turning limit line 64, the turning loose stop line 69, the falling limit line 61, and The area surrounded by the extension of the lodging limit line 62 is the turning gentle stop area.

  According to the first determination process described above, the falling loose stop area or the swing loose stop area is provided between the workable area and the work limit area. As a result, the swing of the upper swing body 30 and the fall of the telescopic boom 32 can be safely and gently stopped. However, at the positions of the intersection points A and B of the falling limit line 62 and the turning limit line 63, the turnable area and the work limit area are in contact with each other. That is, when the tip end of the telescopic boom 32 passes near the intersection points A and B by the combined operation, there is a possibility that the swing of the upper swing body 30 and the falling of the telescopic boom 32 may be suddenly stopped.

  Then, the control unit 50 executes a second determination process (S12). The second determination process is a process of determining a control area. The restriction area is an area that restricts simultaneous execution of the process of turning the upper swing body 30 and the process of laying the telescopic boom 32. The restricted area is, for example, an area different from the falling gentle stop area and the turning gentle stop area in the workable area. The restricted area according to the present embodiment is an area circumscribed to the falling gentle stop area and the turning gentle stop area. However, a part of the restriction area may overlap with the fall gentle stop area or the turn gentle stop area.

  The restriction area in the present embodiment is an area formed around the intersection point A of the falling limit line 62 and the turning limit line 63. More specifically, as shown in FIG. 6, in the restriction area in the present embodiment, the intersection point A is one of the apexes, and an extension of the predetermined length of the lodging limit line 62 is a first outline 62 '. , A graphic region in which an extension of a predetermined length of the turning limit line 63 is a second outline 63 '. Similarly, a restriction area is also formed around the intersection point B of the falling limit line 62 and the turning limit line 64.

  As an example, as shown in FIG. 6A, the control unit 50 has a first outline 62 'which is an extension of a predetermined length of the lodging limit line 62, and a predetermined length of the turning limit line 63. A second contour 63 'which is an extension of the second contour 67', a third contour 67 'which is an extension of the predetermined length of the falling relief stop 67, and an extension of a predetermined length of the turning relief stop 68 A graphic region surrounded by a certain fourth contour 68 'may be determined as a restricted region.

As described above, the inclination angle theta ₁ of the turning slow stop line 68 increases with increasing turning speed, the first contour line 62 ', the turning speed becomes higher the longer faster. In other words, the magnitude of the turning direction of the restricted area increases as the turning speed increases. Further, as described above, lodging radius R ₄ of slow stop line 67 becomes smaller with increasing lodging speed, the second contour line 63 'becomes longer as the lodging speed increases. In other words, the size in the turning radial direction of the restricted area increases as the lodging speed increases.

As another example, as shown in FIG. 6 (B), the control unit 50 sets a first outline 62 'which is an extension of a predetermined length of the lodging limit line 62 and a predetermined outline of the turning limit line 63. a second contour 63 'is a long extension of a graphic region surrounded by the third contour line 70 of the arc shape of radius R ₅ centered on the intersection point a, it may be determined and regulatory region . Control unit 50, as laid down speed is higher, and / or, as the rotation speed is high, may be increased radius R _5. That is, the first contour line 62 'and the second contour line 63' of the restricted area shown in FIG. 6B become longer as the lodging speed is higher and / or the turning speed is higher. Radius R ₅ is an example of a third radius.

  Next, the control unit 50 drives the swing motor 31 and the relief cylinder 35 (S13). Specifically, the control unit 50 supplies hydraulic fluid at a flow rate corresponding to the amount of inclination of the turning lever in the direction corresponding to the direction of inclination of the turning lever to the turning motor 31 to turn the upper turning body 30. In addition, the control unit 50 supplies the hydraulic cylinder 32 with hydraulic oil at a flow rate corresponding to the amount of inclination of the elevation lever in the direction corresponding to the direction of inclination of the elevation lever to cause the telescopic boom 32 to fall. The process of step S13 is an example of the turning and lodging process.

  The control unit 50 continues the swing and lodging process until the operation of the operation unit 56 is completed (S14: No). Moreover, although illustration is abbreviate | omitted, the control part 50 re-executes step S11, S12 according to having changed the amount of operation of a turning lever and an up-and-down lever, or having changed the weight of the hanging load 40. You may On the other hand, when the operation unit 56 is not operated (S14: Yes), the control unit 50 stops the swing motor 31 and the raising and lowering cylinder 35, and ends the operation control process.

  Further, the control unit 50 monitors the position of the tip of the telescopic boom 32 moved by the swing and fall process (S15, S16). The control unit 50 may use, for example, a known method based on the swing angle obtained from the swing angle sensor 51, the elevation angle obtained from the elevation angle sensor 52, and the length of the telescopic boom 32 obtained from the boom length sensor 53. The position of the tip of the telescopic boom 32 can be identified. Then, when the tip end of the telescopic boom 32 is within the workable area (S15: Yes), the control unit 50 continues the swing and lodging process (S13).

  In addition, the control unit 50 causes the swing motor 31 to stop gently (S17) in response to the tip of the telescopic boom 32 being within the swing loose stop region (S15: No & S16: swing loose stop region). The control unit 50 gradually reduces the swing speed of the upper swing body 30 so that the tip of the telescopic boom 32 stops on the swing limit lines 63, 64. More specifically, the control unit 50 gradually reduces the amount of hydraulic oil supplied to the swing motor 31. That is, when the tip end of the telescopic boom 32 is positioned in the swing loose stop area, the control unit 50 does not drive the swing motor 31 according to the operation of the swing lever.

  Further, in response to the tip end of the telescopic boom 32 being within the loose movement stop area (S15: No & S16: loose movement stop area), the control unit 50 causes the relief cylinder 35 to stop gently (S18). The control unit 50 gradually reduces the falling speed of the telescopic boom 32 so that the tip end of the telescopic boom 32 stops on the fall limit lines 61, 62. More specifically, the control unit 50 gradually reduces the amount of hydraulic oil supplied to the relief cylinder 35. That is, when the tip end of the telescopic boom 32 is positioned in the lodging gradual stop area, the control unit 50 does not drive the hoisting cylinder 35 according to the operation of the hoisting lever.

  In step S17, when the tip of the telescopic boom 32 stops on the turning limit lines 63 and 64, the control unit 50 causes the swing speed of the swing motor 31 to have a speed pattern such that the load 40 does not swing in the swing direction. It is desirable to slow down. Similarly, in step S18, when the tip of the telescopic boom 32 is stopped on the turning limit lines 63 and 64, the control unit 50 causes the hanging load 40 to fall down in the turning radial direction so that the lifting cylinder 35 falls down. It is desirable to reduce the speed. Such a speed pattern is determined, for example, by a swing cycle specified by the length from the tip of the telescopic boom 32 to the load 40.

  Furthermore, the control unit 50 executes the slow stop process (S19) in response to the tip of the telescopic boom 32 being the restricted area (S15: No & S16: restricted area). The slow stop process is a process of slow stopping at least one of the swing motor 31 and the relief cylinder 35. Typically, the control unit 50 sets the timing at which the distal end of the telescopic boom 32 enters the restriction area, that is, the distal end of the telescopic boom 32 has a third contour 67 ', a fourth contour 68', or a third contour. The slow stop processing is performed at the timing of passing the intersection point C of the 67 'and the fourth contour 68'. Details of the regulation process will be described with reference to FIG.

  First, the control unit 50 executes notification processing (S31). The notification process is a process of notifying an operator that the tip of the telescopic boom 32 is located within the restriction area. In other words, the notification process is a process of notifying the operator that the swing of the upper swing body 30 and the fall of the telescopic boom 32 should not be simultaneously performed. Although the specific method of notification is not particularly limited, for example, a message may be displayed on a display (not shown) of the overload prevention device, or a warning sound may be output from a speaker (not shown). You may make LED (illustration omitted) etc. light.

  Next, the control unit 50 determines the relationship between the extension line of the movement trajectory of the tip of the telescopic boom 32 moved by the swing and lodging process and the restriction area (S32). The extension line of the movement trajectory of the tip of the telescopic boom 32 can be estimated by the position of the tip of the telescopic boom 32 specified in steps S18 and S19, and the swing speed and the fall speed. The process according to the relationship between the extension line of the estimated movement locus and the restriction area will be described with reference to the example of FIG. 7.

  As shown in FIG. 7A, the control unit 50 determines that the extension line 71 'of the movement trajectory 71 of the telescopic boom 32 intersects the first outline 62' (S32: first The swing motor 31 is gently stopped so that the tip of the telescopic boom 32 is stopped on the swing limit line 63 (S33). The slow stop of the swing motor 31 is common to step S17. Further, the control unit 50 continues driving of the relief cylinder 35 in accordance with the operation signal from the relief lever.

  Further, as shown in FIG. 7B, the control unit 50 determines that the extension line 72 ′ of the movement trajectory 72 of the telescopic boom 32 intersects the second outline 63 ′ (S32: The relief cylinder 35 is gently stopped so that the tip of the telescopic boom 32 stops on the fall limit line 62) (S34). The slow stop of the relief cylinder 35 is common to step S18. Further, the control unit 50 continues driving of the swing motor 31 in accordance with the operation signal from the swing lever.

  Further, as shown in FIG. 7C, the control unit 50 determines that the extension line 73 'of the movement trajectory 73 of the telescopic boom 32 intersects with the intersection point A (S32: intersection point A), The swing motor 31 and the relief cylinder 35 are gently stopped so that the tip end of the telescopic boom 32 stops on the intersection point A (S35). The slow stop of the swing motor 31 is common to step S17, and the slow stop of the relief cylinder 35 is common to step S18.

[Operation and effect of this embodiment]
According to the above-described embodiment, one or both of the swing motor 31 and the raising and lowering cylinder 35 are provided depending on the positional relationship between the extension lines 71 'to 73' of the movement loci 71 to 73 of the tip of the telescopic boom 32 and the restriction area. It is stopped slowly. Then, since the slow stop process is performed at the timing when the tip end of the telescopic boom 32 enters the restriction area, it is possible to secure the distance necessary to safely stop the actuator. As a result, it is possible to suppress the tip end of the telescopic boom 32 from entering the working limit area without stopping the turning and falling suddenly.

  Further, according to the second determination process according to the above-described embodiment, it is possible to determine the restricted area having a size corresponding to the swing speed of the upper swing body 30 and the falling speed of the telescopic boom 32. It is possible to secure the necessary distance for safely stopping the fall of the telescopic boom 32 safely. However, the method of determining the control area is not limited to the above-described example. The restricted region may be, for example, a portion surrounded by the first outline 62 'and the second outline 63' in a rectangular shape having the intersection points A and B as the center of gravity or center.

  7A shows an example in which the movement locus 71 of the tip of the telescopic boom 32 intersects the fourth contour 68 ', and the extension line 71' of the movement locus 71 intersects the first contour 71 '. However, the combination of intersecting edges (or vertices) is not limited to this. For example, in the example of FIG. 7A, the movement locus 71 may intersect the third outline 67 'or the intersection point C, and the extension line 71' of the movement locus 71 may intersect the first outline 62 '. The same applies to FIG. 7 (B) and FIG. 7 (C).

  Further, in the case where the left and right overhang amounts of the outriggers 23 and 24 are the same, the boundaries of the lodging limit lines 61 and 62 are different from the example of FIG. 5. The control unit 50 in this case is, for example, a region sandwiched by a straight line extending from the swing center of the upper swing body 30 to the outrigger 23 on the front side and a straight line extending from the swing center of the upper swing body 30 to the outrigger 24 on the rear side. A first fall limit line is set in the sandwiched area. Further, the control unit 50 is sandwiched by a straight line extending from the turning center of the upper swing body 30 to a straight line extending from the turning center of the upper swing body 30 to the outrigger 23, 24 and a straight line extending from the turning center of the upper swing body 30 to the left outriggers 23, 24 Set a second fall limit line in the Furthermore, of the straight lines extending from the upper swing body 30 to the respective outriggers 23 and 24, the control unit 50 sets a portion sandwiched by the falling limit lines 61 and 62 as the swing limit line.

DESCRIPTION OF SYMBOLS 10 ... Rough terrain crane 20 ... Lower traveling body 30 ... Upper revolving body 31 ... Swing motor 32 ... Telescopic boom 36 ... Irregular cylinder 37 ... Telescopic cylinder 38 ... Rope 50: Control unit 57: Operation unit

Claims (5)

The traveling body,
A rotating body rotatably supported by the traveling body;
A boom supported in an undulating manner on the rotating body;
A pivoting actuator for pivoting the pivoting body;
A relief actuator for raising and lowering the boom;
A first operation unit configured to receive an operation instructing rotation of the rotating body;
A second operation unit that receives an operation to instruct the falling of the boom;
A working vehicle including a control unit,
The control unit
A swing and falldown process for causing the swing actuator to swing the swing body and the lift actuator to tilt the boom in response to simultaneous operation of the first operation unit and the second operation unit;
A first determination process of determining a limit line indicating a boundary of a workable area where entry of the tip of the boom is permitted and a work limit area where entry is prohibited;
A second determination process of determining a control area for restricting the swing lodging process on the workable area side from the limit line;
Performing a gentle stop process to gently stop at least one of the swing actuator and the up and down actuator in response to the tip of the boom entering the restricted area by the swing and fall process;
In the first determination process,
The limit line indicating the boundary of the working limit area where the tip of the collapsed boom is inhibited from entering, the first fall limit line of the arc shape of the first radius, and the first limit in the turning direction A second displacement limit line of a second radius adjacent to the line and smaller than the first radius;
It is the above-mentioned limit line which shows the boundary of the above-mentioned operation limit field by which approach of the tip of the above-mentioned boom by turning of the above-mentioned revolving unit is prohibited, and the mutually adjacent end of the 1st fall limit line and the 2nd fall limit line Determine the turning limit line connecting the
In the second determination process, an intersection of the second falling limit line and the turning limit line is one of apexes, and an extension line of a predetermined length of the second falling limit line is a first contour line, and the turning A graphic area having an extension line of a predetermined length of the limit line as a second outline is determined as the restriction area,
In the above-mentioned slow stop process,
The swing actuator is set so that the tip of the boom stops at the turning limit line in response to the extension line of the movement trajectory of the tip of the boom moved by the turning and laying process crossing the first outline. Stop it slowly,
The work vehicle, according to the extension line of the movement locus crossing the second contour line, gently stopping the relief actuator such that the tip end of the boom stops at the second fall limit line.   The controller looses the swing actuator and the relief actuator such that the tip of the boom stops at the intersection in response to the extension line of the movement trajectory passing the intersection in the slow stop process. The work vehicle according to claim 1, wherein the work vehicle is stopped. The control unit is configured to:
The first outline is made longer as the turning speed of the turning body is higher,
The work vehicle according to claim 1 or 2, wherein the second contour line is lengthened as the lodging speed of the boom is higher. The control unit
In the first determination process,
A first lodging loose stop line extending along the first seating limit line on the workable area side from the first seating limit line and indicating a boundary of a heading suspension stop area for stopping the heading of the boom loosely;
A second lodging loose stop line extending along the second seating limit line on the workable area side from the second seating limit line and indicating the boundary of the lodging loose stop area;
From the turning limit line, extending parallel to the turning limit line on the workable area side, and determining a turning loose stop line indicating the boundary of the turning loose stop area for gently stopping the turning of the turning body;
In the second determination process, the first contour line, the second contour line, and a third contour line which is an extension line of a predetermined length of the second falling loose stop line, and the turning loose stop line. The work vehicle according to any one of claims 1 to 3, wherein the figure area surrounded by the fourth outline which is an extension line of a predetermined length is determined as the restriction area.   In the second determination process, the control unit is configured as the figure surrounded by the first outline, the second outline, and a third outline of an arc shape having a third radius centered on the intersection point. The work vehicle according to any one of claims 1 to 3, wherein an area is determined as the restricted area.

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