JP2006176242A - Safety device of crane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safety device of a crane capable of preventing breakage of a component such as a boom and a jib during the boom collapsing operation. <P>SOLUTION: The safety device comprises a ground contact detection means to detect the ground contact of a tip of a jib 19, and a safety countermeasures taking means to take safety countermeasures for limiting the boom collapsing operation based on the result of detection of the ground contact detection means. The ground contact detection means has a detection body to be displaced according to the ground contact of the tip of the jib 19, and a detector to detect the displacement of the detector. The detection body and the detector are provided on a boom 17, and the detection body is displaced in an interlocking manner with a hanger pin of the jib. The safety countermeasures include an alarm, a stop of the boom collapsing operation, or the like. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a safety device applied to a crane having a boom and a jib.

Conventionally, in a crane equipped with a boom and a jib such as a crawler tower crane, as disclosed in the following Patent Documents 1 and 2, I am trying to fold it. Specifically, as shown in FIG. 17, when the boom 201 is laid down, first, the jib 202 is rotated in a direction in which the tip part descends with the boom 201 standing up, and the jib 202 is moved to the boom 201. It is held (state A in the figure). In this state, the boom 201 is laid down, and when the strut 203 provided at the tip of the boom 201 is grounded, the boom 201 is laid down (state B in the figure). In this way, the strut 203 supports the weight of the boom 201 and the jib 202 so that the overturning operation of the boom 201 is completed.
JP 2002-46981 A JP 2001-302180 A

  However, in the conventional crane, since the boom 201 is laid down with the jib 202 held by the boom 201, the boom 201 depends on the length relationship between the boom 201 and the jib 202 that are actually mounted. There is a risk that the tip of the jib 202 will be grounded before the strut 203 is grounded during the tilting operation, and if the boom 201 continues to fall after the tip of the jib 202 is grounded in this case, the boom 201, the jib 202, etc. There was a risk of breaking the constituent members.

  Therefore, the present invention has been made in view of such a point, and an object of the present invention is to prevent breakage of constituent members such as a boom and a jib during a boom overturning operation.

  To achieve the above object, the present invention is based on a crane safety device including a boom supported by a crane body so as to be raised and lowered, and a jib whose base end is pivotally supported by the boom. A grounding detecting means for detecting the grounding of the tip of the jib during a boom overturning operation, and a safety measure implementing means for implementing a safety measure for limiting the boom overturning operation based on a detection result of the grounding detecting means. It has.

  In this configuration, even if the tip of the jib is grounded, safety measures are implemented in that case, so that it is possible to limit further boom collapse operation. As a result, the boom overturning operation until the boom or jib breaks can be suppressed, and the boom or jib can be prevented from breaking.

  Here, it is preferable that the grounding detection means includes a detection body that is displaced according to the grounding of the tip of the jib and a detection unit that detects the displacement of the detection body. By doing so, the detection unit detects the contact of the tip of the jib by the displacement of the detection body, so that the safety measures can be surely performed before the boom or the like is broken.

  As a specific configuration, if the detection body is arranged at a position where the grounding is possible at the tip of the jib, the detection body can directly detect the grounding of the tip of the jib and reliably detect the grounding. Can be.

  In addition, when the jib is configured to be rotatable to a facing position facing the boom below the boom at the time of lying down, the detection body can be displaced in a direction in which the boom and the jib come into contact with or separate from each other. When the gap between the boom and the jib is narrower than a predetermined width due to the grounding of the tip of the jib that is provided on the boom, the detector is displaced by the pressing of the pressing portion fixed to the jib. It may be configured to. In this configuration, since it is possible to detect a change in the distance between the boom and the jib due to the grounding of the jib tip, safety measures can be surely executed before the boom and the jib collide when lying down.

  In this configuration, the boom is movable between a retaining position that engages with the pressing portion at a portion facing the boom to prevent the boom from being detached, and a separation position that is pulled out from the retaining position. A latching pin is preferably provided. In this configuration, the pressing portion and the latch pin constitute a latch mechanism for holding the boom and the jib at the opposing positions. Therefore, while the boom and jib can be held in an opposed position by this latch mechanism, the boom overturning operation can be performed, while the detection body can be displaced using the pressing portion constituting the latch mechanism. An increase in the number of parts can be suppressed.

  The ground contact detection means includes a boom angle detector, a storage unit for storing data including data relating to the specifications of the boom and jib, a boom angle derived based on the stored data, and the boom angle detector. An arithmetic unit that detects grounding of the tip of the jib based on the detection angle may be provided. In this structure, since the detection result of the boom angle detector normally mounted on the crane can be used, it is possible to suppress an increase in the number of parts such as the detection body.

  The safety measure implementing means may be constituted by an alarm means for issuing an alarm when the grounding of the tip of the jib is detected. By doing so, it is possible to promptly notify the operator that the tip of the jib has contacted the ground, and it is possible to prompt the stop of the boom overturning work before the boom or the like is broken.

  On the other hand, if the safety measure execution means is constituted by a stop means that stops the falling operation of the boom when the contact of the tip of the jib is detected, the boom or the like can be surely obtained regardless of the skill of the operator. Breakage can be prevented.

  In addition, a forecasting unit that emits a forecast sound may be provided when the angle detected by the boom angle detector reaches a predetermined boom angle before the tip of the jib contacts the ground during the boom overturning operation. With this configuration, it is possible to alert the operator in advance and perform a careful operation before entering a dangerous state. As a result, it is possible to prevent danger due to delay in the response of the operator.

  Further, if the detection angle by the boom angle detector reaches a predetermined boom angle before the tip of the jib contacts the ground during the boom overturning operation, if the speed reducing means for reducing the boom overturning speed is provided, the operator's Even if there is a delay in the response, it is easy to avoid danger, and if the jib is grounded, the tripping operation is stopped before the danger is reached. Will be able to.

  In addition, based on data including specifications of the mounted boom and jib, there is provided determination means for determining whether or not there is a boom collapse angle at which the tip of the jib contacts the ground, and the determination means When it is determined that there is a boom overturning angle at which the tip of the jib contacts the ground, the safety measures are implemented, while in other cases the safety measures are not implemented, if necessary Therefore, it is possible to prevent the operability from deteriorating.

  The jib includes a lower jib connected to the boom, an intermediate jib connected to the lower jib, and an upper jib connected to the intermediate jib. While the jib is fixed, a connecting pin that allows the upper jib to bend with respect to the intermediate jib by grounding when pulled out, a pull-out detecting means that detects that the connecting pin has been pulled out, and the connecting pin is pulled out And a safety measure releasing means for restricting the implementation of the safety measure may be provided. In this configuration, if the connecting pin is pulled out, the upper jib is allowed to bend, so that it is possible to further perform the boom overturning operation after the safety measures are implemented. As a result, even when the jib tip is grounded before the strut during the boom overturning operation, the boom or jib can be prevented from being damaged and the safety of the work can be improved.

  As described above, according to the present invention, when it is detected that the tip of the jib is grounded, safety measures for restricting the boom overturning operation are performed. It is possible to prevent the constituent members from being broken.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

Embodiment 1
1 and 2 show an overall configuration of a crane 10 to which a safety device according to an embodiment of the present invention is applied. The crane includes a crane main body 11 and an attachment 12 attached to the crane main body 11. The crane body 11 includes a crawler-type lower traveling body 14 and an upper revolving body 15 mounted on the lower traveling body 14 so as to be rotatable about a vertical axis.

  The attachment 12 includes a boom (tower boom) 17 attached to the crane main body 11 and a jib 19 attached to the distal end portion of the boom 17.

  A boom hoisting rope 23 driven by a boom hoisting winch 21 is joined to the tip of the boom 17 via a spreader 24 and a boom guy line 25. The boom 17 is moved out and retracted by the boom hoisting rope 23. It is designed to move up and down.

  A jib hoisting rope 29 wound and driven by a jib hoisting winch 27 is joined to the tip of the jib 19 via a jib hoisting device (strut) 30 and a jib guy line 31, and the jib 19 is connected to the jib hoisting rope 29. It is designed to rotate by drawing out and retracting. The center of rotation of the jib 19 is the front end on the front side which is the lower side when the boom 17 is laid down. The jib 19 is configured to rotate until it is in a folded state that is substantially parallel to the boom 17 below the boom 17 when lying down.

  The jib 19 is configured by connecting a lower jib 36, an intermediate jib 35, and an upper jib 37. One end of the lower jib 36 is connected to the boom 17, and the other end of the lower jib 36 is connected to one end of the intermediate jib 35. The other end of the intermediate jib 35 is connected to the upper jib 37. A connecting pin 33 is provided at a connecting portion between the intermediate jib 35 and the upper jib 37. The connecting pin 33 pins the intermediate jib 35 and the upper jib 37 at a position opposite to the boom 17 in a state where the jib 19 is folded. A connecting pin is also provided at the position on the boom 17 side. Then, the jib 19 in a state where the connecting pin 33 on the side opposite to the boom 17 (the lower side in FIG. 3) is pulled out is connected to the connecting pin 33 on the boom 17 side when the upper jib 37 is grounded as shown in FIG. It is allowed to bend with respect to the intermediate jib 35 as a center.

  As shown in FIG. 4, the attachment 12 is provided with a latch mechanism 41 that holds the jib 19 in a folded state. Note that when the jib 19 is folded and the boom 17 is laid down, the jib 19 is positioned below the boom 17, so the vertical relationship in FIG. 4 matches the vertical relationship in that state.

  The configuration of the latch mechanism 41 will be specifically described. A boom side bracket 43 is installed between the main columns 17a of the boom 17, and a jib side bracket 45 is installed between the main columns 35a of the intermediate jib 35. Both brackets 43, 45 are arranged in a parallel state when folded.

  The boom side bracket 43 is comprised by a pair of angle material 43a arrange | positioned at predetermined intervals in the length direction of the boom 17, as shown in FIGS. A lock frame 47 is fixed between the angle members 43a. The lock frame 47 is provided with a guide chamber 49 that is open on one side (lower side in FIG. 5 and the like). A side wall portion 49a, 49b facing the boom length direction constituting the guide chamber 49 is provided with a pin guide hole 49c and a lock hole 49d. The pin guide hole 49c is formed through the one side wall portion 49a, and the lock hole 49d is formed through the other side wall portion 49b. And this pin guide hole 49c and the lock hole 49d are arrange | positioned so that the length direction of the boom 17 may be opposed by the lower part of side wall part 49a, 49b.

  In the guide chamber 49, a block member 51 as an example of a receiving portion is disposed so as to be movable in the vertical direction. The block member 51 is provided with a rod member 53 extending upward. A through hole is formed in the upper surface portion 49e of the guide chamber 49, and the rod member 53 protrudes upward from the upper surface portion 49e through the through hole.

  A coil spring 55 is disposed between the upper surface portion 49 e of the guide chamber 49 and the block member 51 so as to be fitted on the rod member 53. The coil spring 55 is provided to reliably block the pin guide hole 49c and the lock hole 49d by positioning the block member 51 downward during normal operation.

  A support member 57 protrudes from the lock frame 47, and a lever 59 is supported on the support member 57 so as to be swingable. One end (lower end) of the lever 59 is provided with a latch pin 61 whose tip is inserted into the pin guide hole 49c. The latch pin 61 is disposed so as to extend in the boom length direction. The latch pin 61 is inserted into the pin guide hole 49c only by the swing of the lever 59 (FIG. 5). It moves forward and backward between a pinning hole 49c and a locking position (FIGS. 6 and 7) straddling the lock hole 49d.

  Between the lever 59 and the lock frame 47, an urging member 63 that urges the latch pin 61 in a direction to enter the pin guide hole 49c is disposed.

  On the other hand, the jib side bracket 45 is provided with a pair of leg members 66, 66 protruding toward the boom side bracket 43. The leg members 66 and 66 are arranged at intervals in a direction orthogonal to the jib length direction, and a hanger pin 68 is provided between the tip portions of the leg members 66 and 66. The hanger pin 68 constitutes a pressing portion referred to in the present invention. Since the hanger pin 68 is fixed in a posture extending in a direction orthogonal to the length direction of the jib 19, the hanger pin 68 is in an orthogonal arrangement relationship with the latch pin 61 when the jib 19 is folded. When the jib 19 is in the folded state, the hanger pin 68 approaches the boom side bracket 43 beyond the position of the latch pin 61, pushes up against the block member 51, and the pin guide hole 49c opens to latch. The pin 61 is moved forward to the retaining position so that the hanger pin 68 is retained (see FIG. 6). In this state, the hanger pin 68 is positioned above the latch pin 61, and a portion of the latch pin 61 facing the boom 17 is engaged with the hanger pin 68. The block member 51 is placed on the hanger pin 68.

  When the tip of the jib 19 is grounded in this state, the upper jib 37 is pushed to the ground and the jib side bracket 45 approaches the boom side bracket 43. At this time, the hanger pin 68 is moved as shown in FIG. It will rise further. And if the fall operation of the boom 17 is continued, the hanger pin 68 will operate | move so that the block member 51 may be pushed up. Along with this, the rod member 53 also rises.

  As shown in FIG. 4, the boom-side bracket 43 is provided with a stopper 70 that protrudes toward the jib-side bracket 45. This stopper 70 is for preventing the space | interval between both brackets 43 and 45 from approaching the grade which the structural member breaks.

  As shown in FIG. 4, the attachment 12 is provided with a grounding detection means 72 that detects the grounding of the tip of the jib 19 when lying down. The ground detection means 72 includes a detection body 73 attached to the rod member 53 and a detector 74 as an example of a detection unit that detects the displacement of the detection body 73.

  A screw hole penetrating vertically is formed in the detection body 73, and a male screw is cut at the tip of the rod member 53. The detection body 73 is attached to the rod member 53 by being screwed to the male screw, and the upper and lower sides thereof are sandwiched between the double nuts, and the detection body 73 is attached to the rod member 53 while allowing the vertical position adjustment. It is fixed. Thereby, the detection body 73 moves integrally with the block member 51.

  The detection body 73 is formed in a shape in which a through hole provided in the upper surface portion 49e of the guide chamber 49 cannot pass. Accordingly, the state where the detection body 73 is placed on the upper surface portion 49e of the guide chamber 49 becomes the lower end position.

  The detector 74 is constituted by a limit switch, and this detector 74 is attached to an attachment plate 77 fixed to the angle member 43a. When the detection body 73 is displaced to a detection position that is a predetermined distance away from the lower end position, the detector 74 is configured to push up the sensor unit to be turned on and output a detection signal.

  Next, a control system of the crane 10 to which the safety device according to the first embodiment is applied will be described with reference to FIG.

  As illustrated in FIG. 8, the crane 10 includes a controller 80, and the controller 80 includes an input unit 81, a calculation unit 82, a memory unit 83, and an output unit 84. The memory unit 83 stores control maps, data, and programs. When the calculation unit 82 executes these control maps, data, and programs, the controller 80 has a determination unit 86, a deceleration unit 87, and a forecast. Means 88, alarm means 89, and stop means 90 are functionally included (see FIG. 9).

  The controller 80 receives a detection signal from the boom angle detector 92, a detection signal from the detector 74, and a signal from the attachment specification input device 94, and outputs a boom collapse deceleration signal, a boom stop signal, a forecast signal, and an alarm signal. Output. The boom angle detector 92 is a known one and is installed on the boom 17.

  Based on the data including the boom length data, the jib length data, the strut 30 shape data, etc., input to the attachment specification input device 94, the determination means 86 makes contact with the tip end of the jib 19 when the boom falls. It is determined whether or not there is an overturning angle, and the overturning angle is derived. That is, it is calculated whether or not the tip end of the jib 19 is grounded before the strut 30 is grounded when lying down, and the fall angle at which the tip of the jib 19 is grounded is derived. In addition, as the controller 80 and the attachment specification input device 94, an overload prevention device mounted on the crane 10 can be used.

  The deceleration means 87 outputs a boom fall deceleration signal when the boom angle detector 92 detects a predetermined angle (for example, 15 degrees) when the boom 17 is fallen. The boom raising and lowering electromagnetic proportional valve 96 is configured to decelerate the falling speed of the boom 17 when this signal is input.

  The forecast means 88 outputs a forecast signal when the angle detected by the boom angle detector 92 reaches the predetermined angle (for example, 15 degrees). The forecast alarm 98 is configured to emit a forecast sound when a forecast signal is input.

  The alarm means 89 outputs an alarm signal when the detection signal output from the detector 74 is input. The forecast alarm 98 is configured to emit an alarm sound when an alarm signal is input.

  The stop means 90 outputs a boom stop signal when the detection signal output from the detector 74 is input. The boom 17 raising and lowering electromagnetic proportional valve 96 is configured to stop the falling operation of the boom 17 when this signal is input.

  The operation of the crane configured as described above will be described with reference to FIG.

  First, in step S1, data including boom length data, jib length data, strut 30 shape data, etc. stored in the memory unit 83 is read. In step S2, the jib 19 It is determined based on the data read out in step S1 whether or not there is an inclining angle at which the front end of the ground contacts. If it is determined that the boom 17 or the like does not have such a tilt angle, the process ends without executing the following control. On the other hand, if it is determined in step S2 that the combination has a lying angle at which the tip of the jib 19 contacts the ground, the process proceeds to step S3. That is, the safety measures for limiting the boom overturning operation described below are performed only when it is determined that there is an overturning angle at which the tip of the jib 19 contacts the ground.

  In step S3, the boom angle detected by the boom angle detector 92 is read, and in step S4, it is determined whether or not the detected angle is 15 degrees or less during the lying down operation. The process returns to step S3 until it reaches 15 degrees, but if it becomes 15 degrees or less, the process proceeds to step S5, where the falling speed of the boom 17 is reduced and a forecast sound is emitted. At this time, the rate of deceleration is gradually increased according to the amount of change in the detection angle of the boom angle detector 92. In this manner, the operator can detect the danger of the tip of the jib 19 coming into contact with the deceleration of the lodging speed and the forecast sound, and can prompt the operator to carefully perform the lodging operation.

  Then, when the inclining operation of the boom 17 is continued thereafter, it is determined whether or not the detector 74 is turned on in step S6. That is, when the tip of the jib 19 is grounded and the boom 17 is subsequently laid down, the hanger pin 68 of the latch mechanism 41 pushes up the block member 51 (see FIGS. 6 and 7). As 73 rises, the detector 74 monitors the rise of the detection body 73.

  When the detector 74 is turned on, the process proceeds from step S6 to step S7, where an alarm sound is generated instead of the forecast sound, and control for stopping the overturning operation of the boom 17 is executed. At this time, the jib side bracket 45 is in a state immediately before it abuts against the stopper 70.

  Thereafter, in step S8, it is determined whether or not the detector 74 is turned off. The process returns to step S7 until the detector 74 is turned off. On the other hand, if the detector 74 is turned off, the process proceeds to step S9. This is because when the connecting pin 33 that connects the intermediate jib 35 and the upper jib 37 is pulled out and the upper jib 37 can be bent with respect to the intermediate jib 35 (see FIG. 3), the intermediate jib 35 is lowered. Since the space | interval of the boom 17 and the intermediate jib 35 spreads, it has detected. When the detector 74 is turned off, the alarm is released and the stop control of the lodging operation is released. As a result, further overturning operation is possible, the operator can further lower the boom 17, and the strut 30 can be placed on the ground.

  As described above, according to the first embodiment, even if the tip of the jib 19 is grounded, safety measures are performed in that case, so that further boom collapse operation can be restricted. As a result, the boom overturning operation until the boom 17 and the jib 19 are broken can be suppressed, and the components such as the boom 17 and the jib 19 can be prevented from being broken.

  Furthermore, in this Embodiment 1, since it is the structure which detects that the space | interval between the boom 17 and the intermediate jib 35 changes by the earthing | grounding of the jib 19 front-end | tip part, the boom 17 and the intermediate jib 35 collide at the time of a fall. Safety measures can be reliably implemented before.

  Further, in the first embodiment, the boom overturning operation can be performed in a state where the boom 17 and the jib 19 are held at the opposing positions by the latch mechanism 41, while the hanger pins 68 constituting the latch mechanism 41 are used. Since the detection body 73 can be displaced, it can suppress that a number of parts increases. In addition, by detecting the displacement of the detection body 73, it is possible to prevent breakage of parts constituting the latch mechanism 41.

  In the first embodiment, an alarm is issued when the grounding of the tip of the jib 19 is detected, so that the operator can be quickly notified that the tip of the jib 19 is grounded. As a result, the boom overturning operation can be stopped before the boom 17 or the like is broken.

  Further, in the first embodiment, when the ground contact of the tip of the jib 19 is detected, the control for stopping the lying down operation is performed, so that the breakage of the boom 17 and the like is surely prevented regardless of the skill of the operator. be able to.

  In the first embodiment, the forecast sound is generated before the ground contact of the tip of the jib 19 is detected. Therefore, the operator is warned in advance and a careful operation is performed before the dangerous state is reached. It becomes possible. As a result, it is possible to prevent danger due to delay in the response of the operator.

  In the first embodiment, since deceleration control is performed before the contact of the tip of the jib 19 is detected, even if there is a delay in the response of the operator, it is easy to avoid from danger. In addition, when the overturning operation is stopped when the jib 19 is grounded, the overturning operation of the boom 17 can be surely stopped before reaching danger.

  Further, in the first embodiment, since the safety measures are implemented only when it is determined that there is an inclining angle at which the tip of the jib 19 contacts, it is possible to prevent the operability from deteriorating.

  If the connecting pin 33 is pulled out when the tip end of the jib 19 is in the grounded position, the upper jib 37 is bent and the distance between the boom 17 and the intermediate jib 35 is changed. Since the displacement of the gap between the intermediate jib 35 and the intermediate jib 35 is detected, the detection of the displacement of the detection body 73 can be used to detect whether or not the connecting pin 33 has been pulled out.

  In the first embodiment, when the detector 74 is turned on, the control for generating an alarm sound and the control for stopping the falling operation of the boom 17 are executed. Instead, as shown in FIG. Two detectors 74A and 74B may be provided on the mounting plate 77. In this configuration, both detectors 74A and 74B are arranged so as to be displaced in the moving direction of the detection body 73, and the displacement amount of the detection body 73 can be detected in two stages. That is, the first detector 74A detects that the detector 73 has been displaced to a first position that is a first predetermined distance away from the lower end position. On the other hand, the second detector 74B detects that the detector 73 has been displaced to a second position separated from the lower end position by a second predetermined distance that is longer than the first predetermined distance. The first detector 74A and the second detector 74B are configured to output a detection signal when the detection body 73 is in an on state in which the sensor unit is pushed up. In this configuration, control is performed to issue an alarm when the first detector 74A is turned on, and the stop operation of the lodging operation is stopped when the detector 73 is displaced and the second detector 74B is turned on. Can be configured.

<< Embodiment 2 >>
In the second embodiment of the present invention, the contact of the tip of the jib 19 is directly detected at the tip of the upper jib 37. That is, as shown in FIG. 12, a detector 73 and a detector 74 are provided at the tip of the upper jib 37. Here, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  A pair of hoisting rope sheaves 101 and 102 are disposed at the tip of the upper jib 37. The winding rope sheaves 101 and 102 are respectively installed on the front side which is the hook side and the back side which is the winding winch side with the upper jib 37 interposed therebetween. Here, FIG. 12 shows a state when the boom 17 is laid down with the jib 19 folded, and the upper sheave in FIG. 12 becomes the front sheave 101, and the lower sheave in FIG. It is a back side sheave 102. The bracket 104 that supports the back side sheave 102 is provided with a support 106 that prevents the back side sheave 102 from being grounded.

  The support 106 includes a base portion 106a fixed to the bracket 104. The base portion 106a includes a side wall portion 106b having a U-shaped cross section as shown in FIGS. 13 (a) and 13 (b). A support plate 106c is fixed inside the character. A detection body 73 is supported by the base portion 106a so as to be displaceable with respect to the base portion 106a. Similarly to the base portion 106a, the detector 73 has a side wall portion having a U-shaped cross section. Is fixed. And the spring member 108 which consists of a coil spring is interposing between the top-plate part 73a and the support plate 106c, and when the grounding surface part 73b earth | grounds the detection body 73, the spring member 108 will shrink | contract with respect to the base part 106a. Relative displacement is achieved. As described above, the support 106 includes the base 106 a and the detection body 73.

  The detector 74 is constituted by a limit switch and is attached to the side wall portion 106b of the base portion 106a. And when the detection body 73 approaches the base 106a by a predetermined distance from the stationary state due to grounding, the detection body 73 is turned on and outputs a detection signal.

  As shown in FIGS. 14 (a) and 14 (b), the attachment 12 is provided with a pull-out detection means 110 for detecting that the connecting pin 33 has been pulled out. That is, in the second embodiment, since the configuration in which the tip of the upper jib 37 is directly grounded is detected, the detection body 73 constituting the support 106 is grounded regardless of whether or not the connecting pin 33 is pulled out. As long as it is, the detection body 73 is not displaced. For this reason, when the connecting pin 33 is pulled out as in the first embodiment, the detection body 73 is not displaced in conjunction with it, so in the second embodiment, the pulling-out detection means 110 is provided.

  The extraction detection unit 110 includes a storage unit 112 for storing the extracted connection pin 33 and a storage detection unit 114 for detecting that the connection pin 33 is stored in the storage unit 112. The storage portion 112 is formed of a cylindrical body through which the connecting pin 33 can be inserted, for example, and is fixed to the intermediate jib 35. The storage detection unit 114 is configured by a limit switch fixed to the intermediate jib 35 and disposed below the storage unit 112. When the connection pin 33 is stored in the storage unit 112, the tip of the connection pin 33 is stored. It arrange | positions in the position which a part contact | abuts. When the connecting pin 33 comes into contact and is turned on, a detection signal is output. As a result, it is possible to detect that the connecting pin 33 has been pulled out.

  In the second embodiment, unlike the first embodiment, the latch mechanism 41 is not provided with the detector 73 and the detector 74.

  As shown in FIG. 15, the controller 80 functionally includes a determination unit 86, a deceleration unit 87, a forecast unit 88, an alarm unit 89, a stop unit 90, and a safety measure release unit 117. Yes. The determination unit 86, the deceleration unit 87, the forecast unit 88, the alarm unit 89, and the stop unit 90 are the same as those in the first embodiment.

  The safety measure canceling means 117 is configured to stop the forecast sound and the alarm sound and cancel the stop control of the boom 17 when the detection signal from the storage detection unit 114 is input.

  Operation | movement of the crane 10 of this Embodiment 2 is demonstrated based on FIG.

  Steps S10 to S14 are performed in the same manner as steps S1 to S5 in the first embodiment, and the process proceeds to step S15. In step S15, it is determined whether or not the detector 74 is turned on. In other words, if the boom 17 continues to fall even after the detector 73 at the tip of the upper jib 37 is grounded, the detector 74 will monitor it because the base 106a of the support 106 is displaced more than a predetermined value. ing.

  Then, when the detector 74 is turned on, the process proceeds from step S15 to step S16, where an alarm sound is generated instead of the forecast sound, and control for stopping the inclining operation of the boom 17 is executed. Then, the process proceeds to step S17, where it is determined whether or not the connecting pin 33 has been pulled out and stored in the storage unit 112. The process returns to step S16 until the storage in the storage unit 112 is detected, and when the storage is detected, the process proceeds to step S18. In step S18, the alarm is released and the stop control of the boom 17 is released. That is, since the upper jib 37 can be bent with respect to the intermediate jib 35 when the connecting pin 33 is pulled out, the boom 17 can be further lowered by releasing the stop control of the boom 17.

  As described above, according to the second embodiment, the detection body 73 can directly detect the ground contact at the tip of the jib 19 and can ensure the ground contact detection.

  In the second embodiment, the detection body 73 is provided at the tip of the jib 19 and the grounding of the tip of the jib 19 is detected by the displacement of the detection body 73. Even in the broken state, unlike the first embodiment, the withdrawal of the connecting pin 33 cannot be directly detected by the displacement of the detection body 73. However, it is possible to detect whether or not the connecting pin 33 has been pulled out by providing the pull-out detecting means 110. Since the implementation of the safety measure is canceled when the connecting pin 33 is pulled out, it is possible to further perform the boom overturning operation even after the safety measure is once implemented. As a result, even when the tip of the jib 19 is grounded earlier than the strut 30 during the boom overturning operation, the boom 17 and the jib 19 can be prevented from being damaged, and the safety of work can be improved.

  Other configurations, operations, and effects are the same as those in the first embodiment although the description thereof is omitted.

  As another embodiment, the ground contact detection means 72 includes a boom angle detector 92, a memory unit 83 as an example of a storage unit that stores data including data regarding the specifications of the boom 17 and the jib 19, and the memory unit 83. It is good also as a structure provided with the calculating part which detects the earthing | grounding of the jib 19 front-end | tip based on the boom angle derived | led-out based on the data memorize | stored in, and the detection angle of the boom angle detector 92. That is, the fall angle at which the tip of the jib 19 is grounded is derived from the data of the boom 17 and the like input by the operator and the tip of the jib 19 is reached when the detected angle by the boom angle detector 92 is reached. It is good also as a structure which determines with having earth | grounded.

It is the schematic which shows the whole structure of the crane with which the safety device which concerns on Embodiment 1 of this invention was applied. It is the schematic which shows the state by which the boom of the said crane was laid down. It is a figure which shows the state which the connection pin was pulled out in the fall state in the said crane, and the upper jib broke. It is a figure which shows the structure of the latch mechanism and grounding detection means which were provided in the said crane. It is a figure which shows the said latch mechanism in the state which has the pin for latch in a detachment position. It is a figure which shows the said latch mechanism in the state which has a pin for latch in a removal prevention position. It is a figure which shows the said latch mechanism in the state which the hanger pin raised further from the state of FIG. It is a block diagram which shows the structure of the control system of the said controller. It is a figure which shows the structure of the function contained in the said controller. It is a flowchart which shows the control action of the said crane. It is a figure which shows the structure of the earthing | grounding detection means in another embodiment of this invention. It is a figure which shows the structure of the upper jib front-end | tip part in Embodiment 2 of this invention. The support arrange | positioned at the upper jib front-end | tip part of FIG. 12 is shown, (a) is a rear view, (b) is a bottom view. The drawing detection means is shown, (a) is a state before the connection pin is stored, and (b) is a state after the connection pin is stored. It is a figure which shows the structure of the function contained in the controller in Embodiment 2 of this invention. It is a flowchart which shows the control action of the crane with which the safety device which concerns on Embodiment 2 of this invention was applied. It is a figure which shows the whole structure of the conventional crane.

Explanation of symbols

11 Crane body 17 Boom 19 Jib 33 Connecting pin 35 Intermediate jib 36 Lower jib 37 Upper jib 51 Block member (an example of receiving part)
61 Pin for latch 68 Hanger pin (example of pressing part)
72 Ground detection means 73 Detector 74 Detector (an example of a detector)
74A 1st detector (an example of a detection part)
74B 2nd detector (an example of a detection part)
82 arithmetic unit 83 memory unit (an example of a storage unit)
86 Judgment means 87 Deceleration means 88 Forecast means 89 Alarm means (an example of safety measure means)
90 Stopping means (an example of safety measure means)
92 Boom angle detector 110 Pull-out detection means 117 Safety measure release means

Claims (12)

A crane safety device comprising a boom supported by a crane body so as to be raised and lowered, and a jib whose base end is rotatably supported by the boom,
A grounding detecting means for detecting the grounding of the tip of the jib during boom overturning operation;
A crane safety device comprising: safety measure implementing means for implementing a safety measure for restricting boom overturning operation based on a detection result of the ground contact detection means.   2. The crane according to claim 1, wherein the grounding detection unit includes a detection body that is displaced according to the grounding of the tip of the jib and a detection unit that detects the displacement of the detection body. Safety equipment.   The crane safety device according to claim 2, wherein the detection body is disposed at a position at which a tip of the jib can be grounded. The jib is configured to be rotatable to a facing position facing the boom below the boom when lying down,
The detection body is provided on the boom so as to be displaceable in a direction in which the boom and the jib come into contact with and away from each other.
When the distance between the boom and the jib becomes narrower than a predetermined width due to the grounding of the tip of the jib at the opposing position, the detection body is displaced by the pressing of the pressing portion fixed to the jib. The crane safety device according to claim 2.   The boom has a latch pin that is movable between a retaining position that engages with the pressing portion at a portion facing the boom to prevent the boom from being detached, and a disengagement position that is pulled out from the retaining position. The crane safety device according to claim 4, wherein the crane safety device is provided.   The ground contact detection means includes a boom angle detector, a storage unit for storing data including data relating to specifications of the boom and jib, a boom angle derived based on the stored data, and the boom angle detector. The crane safety device according to claim 1, further comprising a calculation unit that detects grounding of the tip of the jib based on the detection angle.   The crane safety according to any one of claims 1 to 6, wherein the safety measure executing means is configured by an alarm means that issues an alarm when the grounding of the tip of the jib is detected. apparatus.   7. The safety measure implementing means according to any one of claims 1 to 6, characterized in that the safety measure implementing means is constituted by stop means for stopping the boom overturning operation when the grounding of the tip of the jib is detected. Crane safety device as described.   9. A forecasting means for generating a forecasting sound is provided when a detected angle by the boom angle detector reaches a predetermined boom angle before the tip of the jib contacts the ground during a boom overturning operation. The safety device for a crane according to any one of the above.   A decelerating means is provided for decelerating the boom fall speed when the angle detected by the boom angle detector reaches a predetermined boom angle before the tip of the jib contacts the ground during boom collapse operation. Item 10. The crane safety device according to any one of Items 1 to 9. Based on data including specifications of the mounted boom and jib, there is provided determination means for determining whether or not there is a boom collapse angle at which the tip of the jib contacts the ground,
The safety measures are implemented when it is determined by the judging means that there is a boom overturning angle at which the tip of the jib contacts the ground, while in other cases the safety measures are not implemented. The crane safety device according to any one of claims 1 to 10, wherein: The jib comprises a lower jib connected to the boom, an intermediate jib connected to the lower jib, and an upper jib connected to the intermediate jib.
A connecting pin that fixes the upper jib relative to the intermediate jib, while allowing the upper jib to bend against the intermediate jib when grounded,
A pull-out detecting means for detecting that the connecting pin has been pulled out;
The crane safety device according to any one of claims 1 to 11, further comprising safety measure release means for restricting execution of the safety measure when the connecting pin is pulled out.

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