JP6237721B2 - Crane and method for removing crane's telescopic member - Google Patents

Description

  The present invention relates to a crane and a method for removing a telescopic member of the crane.

  Conventionally, a lower traveling body that can travel, an upper revolving body that is pivotably attached to the lower traveling body, a boom that is removably attached to the upper revolving body, and a boom suspended from the tip of the boom In a crane provided with a hook, in order to prevent the boom from falling toward the ground, a counterweight disposed behind the upper swing body and connected to the boom is connected to the upper swing body and the counterweight. A device further provided with a support is known (for example, see Patent Document 1). In the crane of Patent Document 1, the boom and the counterweight are balanced by the expansion and contraction of the support so that the separation distance between the upper swing body and the counterweight changes according to the boom undulation state. Falling down is suppressed.

JP 2011-162306 A

  In the crane of Patent Document 1, when the telescopic member corresponding to the support is removed from the upper swing body and the counterweight and transported, it is preferable that the telescopic member is contracted to the shortest length.

  However, when the telescopic member expands and contracts by receiving a driving force from the upper swing body or the counterweight, the telescopic member is removed from the upper swing body and the counterweight after being contracted by the driving force and then transported. Since it is necessary, it may be difficult to shrink the elastic member to the shortest length. Specifically, it is as follows.

  General cranes are equipped with an overload prevention device. If the total rated load of the crane becomes 0 due to a decrease in the distance between the upper swing body and the counterweight, the crane's safety is taken into consideration. The overload prevention device prohibits the separation distance between the upper swing body and the counterweight from being shortened further. For this reason, when the rated total load of the crane becomes 0 in the middle of the expansion member when the expansion member is to be shortened to the shortest length, the overload prevention device is activated, whereby the expansion member can be shortened to a shorter length. become unable.

  This invention is made | formed in view of said point, The objective is to provide the crane which can shrink an expansion-contraction member, ensuring safety | security, and the removal method of the expansion-contraction member of a crane.

  A crane according to the present invention includes a fuselage, a front attachment attached to the fuselage so as to be able to undulate in front of the fuselage and capable of hanging a suspended load, and disposed at the rear of the fuselage and the front attachment. A counterweight connected to the front attachment so as to be balanced with each other, and a telescopic member that connects the machine body and the counterweight and can be expanded and contracted so as to change a separation distance between the machine body and the counterweight. An operation unit that performs a contracting operation to contract the expansion / contraction member to a predetermined length between a maximum length of the expansion / contraction member and a minimum length of the expansion / contraction member by a driving force from the machine body or the counterweight; and the front attachment The front door at the predetermined length based on the posture of the A calculation unit for calculating a rated total load of the stitching, and allowing the contraction operation in the operation unit when the rated total load calculated in the calculation unit exceeds a predetermined value, while calculating the calculation unit in the calculation unit A contraction operation prohibition unit that prohibits the contraction operation in the operation unit when a rated total load is a predetermined value or less, a measurement unit that measures a suspension load in the front attachment, and the suspension load measured in the measurement unit And a contraction operation prohibition control unit that cancels the prohibition of the contraction operation by the contraction operation prohibition unit and permits the contraction operation when the load is equal to or less than a preset allowable load.

  In the crane described above, the telescopic member can be shortened to a predetermined length while ensuring safety. Specifically, it is as follows.

  In the crane described above, when a contracting operation for contracting the telescopic member to a predetermined length is performed in the operating unit, the contracting operation prohibiting unit allows the contracting operation when the rated total load calculated by the calculating unit exceeds a predetermined value. On the other hand, the shrinking operation is prohibited when the rated total load is not more than a predetermined value. Thereby, an expansion-contraction member can be shortened to predetermined length only in the state where the safety of the crane was ensured because the rated total load exceeded a predetermined value.

  By the way, even if the rated total load when the elastic member is contracted to a predetermined length is not more than a predetermined value, the safety is ensured in the case where the front attachment is not substantially hanging the suspended load. It is possible to shrink the elastic member to a predetermined length.

  Accordingly, the contraction operation prohibition control unit cancels the prohibition of the contraction operation and allows the contraction operation when the suspension load measured by the measurement unit is equal to or less than the allowable load. As a result, even if the rated total load at a predetermined length is less than or equal to a predetermined value, when the front attachment is in a state of not substantially hanging a suspended load, the contraction operation is permitted and the expansion / contraction member has a predetermined length. It can be shrunk. For this reason, the elastic member can be shortened to a predetermined length while ensuring safety.

  The allowable load is set to the maximum suspended load when the front attachment is not substantially suspended from the suspended load.

The front attachment includes a hanging tool for hanging the suspended load, and the hanging load measured by the measuring unit includes a weight of the hanging tool, and is set in advance in the contraction operation prohibition control unit. It is preferable that the allowable load thus set is set to a value exceeding the weight of the suspension tool.

  In the above crane, since the suspension load includes the weight of the suspension tool and the allowable load is set to a value exceeding the weight of the suspension tool, the front attachment substantially suspends the suspension load in the contraction operation prohibition control unit. Thus, it is possible to more accurately determine whether or not there is a state in which the elastic member can be shortened to a predetermined length while ensuring safety.

  The crane telescopic device removal method according to the present invention includes an airframe, a front attachment attached to the airframe so that it can be raised and lowered in front of the airframe, and capable of hanging a suspended load, and disposed behind the airframe. The counter weight connected to the front attachment is connected to the front attachment so as to be balanced with the front attachment, and the machine body and the counter weight are connected to each other, and the distance between the machine body and the counter weight is changed. Based on the posture of the front attachment, a possible expansion member, an operation unit that performs a contraction operation to contract the expansion member to a predetermined length between a longest length and a shortest length by a driving force from the machine body or the counterweight The front attach at the predetermined length A calculation unit that calculates the rated total load of the control unit, and the contraction operation in the operation unit when the rated total load calculated in the calculation unit exceeds a predetermined value, while the calculation unit calculates the A method for removing the contraction member after contracting to the predetermined length in a crane including a contraction operation prohibition unit that prohibits the contraction operation in the operation unit when the rated total load is a predetermined value or less, The measurement process of measuring the suspension load in the front attachment is compared with the suspension load measured in the measurement process and a preset allowable load, and the suspension load measured in the measurement process is equal to or less than the allowable load. When it is determined, the contraction operation permission step of canceling the prohibition of the contraction operation by the contraction operation prohibition unit and permitting the contraction operation; and After shortened up of, and a removal step of removing the elastic member from the fuselage and the counterweight.

  In the above method for removing the telescopic member of the crane, the telescopic member can be retracted to a predetermined length and removed while ensuring safety. Specifically, it is as follows.

  In the above method for removing the telescopic member of the crane, the contraction operation prohibiting unit allows the contraction operation when the rated total load calculated by the calculation unit exceeds a predetermined value, while the rated total load is equal to or less than the predetermined value. In this case, the shrink operation is prohibited.

  By the way, even if the rated total load when the elastic member is contracted to a predetermined length is not more than a predetermined value, the safety is ensured in the case where the front attachment is not substantially hanging the suspended load. It is possible to shrink the elastic member to a predetermined length.

  Therefore, in the above method for removing the telescopic member of the crane, the suspension load is measured in the measurement step, and the prohibition of the contraction operation is canceled and the contraction operation is permitted only when the suspension load is equal to or less than the allowable load. Thereby, even if the rated total load at the predetermined length is equal to or less than the predetermined value, when the front attachment is in a state of not substantially hanging the suspended load, the elastic member can be contracted to the predetermined length. For this reason, it is possible to remove the telescopic member by contracting it to a predetermined length while ensuring safety.

  The allowable load is set to the maximum suspended load when the front attachment is not substantially suspended from the suspended load.

  The front attachment has a suspension for suspending the suspended load, and in the measurement step, the suspension load including the weight of the suspension is measured, and the suspension load measured in the measurement step It is preferable to compare the allowable load set to a value exceeding the weight of the hanging tool.

  In the above method for removing the telescopic member of the crane, since the suspension load includes the weight of the suspension tool and the allowable load is set to a value exceeding the weight of the suspension tool, the front attachment substantially suspends the suspension load. It is possible to accurately determine whether or not there is a state in which the elastic member is not present, and thereby the elastic member can be shortened to a predetermined length while ensuring safety.

  As described above, according to the present invention, there are provided a crane capable of contracting the telescopic member while ensuring safety, and a method for removing the telescopic member of the crane.

It is a schematic side view which shows the structure of the crane which concerns on this embodiment. It is a block diagram which shows the rear end position control apparatus of the crane which concerns on this embodiment. It is a chart figure which shows the method of shrinking an expansion-contraction member to predetermined length, when removing the expansion-contraction member of the crane concerning this embodiment from the crane concerned.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, for convenience of explanation, the drawings to be referred to below show only the main members among the constituent members of the crane X1 according to the present embodiment in a simplified manner. Therefore, the crane X1 according to the present embodiment may include any constituent member or any process that is not shown in each drawing referred to in this specification.

  FIG. 1 shows a crane X1 according to the present invention. A crane X1 shown in FIG. 1 travels and turns the crane X1, a front attachment 3 that lifts and suspends a suspended load, a mast 4 that supports the front attachment 3, a front attachment 3, and a mast 4 And a boom guy line 5 connecting the two.

  The airframe has a lower traveling body 1 and an upper swing body 2 disposed on the lower traveling body 1. The lower traveling body 1 is configured to be able to travel on the ground G and includes, for example, a pair of left and right crawlers. The upper swing body 2 is configured to be able to swing around an axis extending in a direction perpendicular to the ground G on which the lower travel body 1 travels. The upper swing body 2 includes, for example, a cab on which an operator of the crane X1 is boarded.

  The front attachment 3 performs a lifting work and a hanging work of the luggage. The front attachment 3 includes a boom 31 and a hanging tool 32.

  The boom 31 is attached to the upper swing body 2 so that the boom 31 can be raised and lowered in front of the upper swing body 2.

  The hanging tool 32 has a hook wire rope 32b and a hook 32a. The hook wire rope 32b extends from the proximal end to the distal end of the boom 31 along the longitudinal direction of the boom 31, and is suspended from the distal end. The hook 32 a is attached to a hook wire rope 32 b suspended from the tip of the boom 31.

  The mast 4 supports the boom 31 from behind so that the boom 31 does not fall forward of the upper swing body 2. The mast 4 has a mast main body 41 and a backstop 42.

  The mast main body 41 is attached to the upper swing body 2 so as to incline backward with respect to the boom 31. The tip of the mast body 41 and the tip of the boom 31 are connected by a boom guy line 5. More specifically, a wire rope attached to a spreader is connected to the tip of the mast main body 41, and a boom guy line 5 is connected to the wire rope. Thereby, the boom 31 is supported from the rear by the mast main body 41.

  The backstop 42 supports the mast body 41 so that the mast body 41 does not fall backward. The base end of the backstop 42 is located behind the base end of the mast main body 41 attached to the upper swing body 2 and is attached to the upper swing body 2. The tip of the backstop 42 is attached to a part of the mast body 41 in the longitudinal direction. Thereby, the mast main body 41 is supported from the back by the backstop 42.

  For example, the operator of the crane X1 gets on the cab of the upper swing body 2 and moves the lower travel body 1 and rotates the upper swing body 2 in the cab, so that the crane X1 can be used. Move to the place you want. Then, by driving the hoisting winch mounted on the upper swing body 2 and winding the wire rope connected to the boom guy line 5, the hoisting angle with respect to the ground G of the boom 31 is changed and the upper swing body 2 is mounted. By driving the wound winch and winding the hook wire rope 32b, the suspended load suspended from the hook 32a is moved in the vertical direction.

  Here, the crane X <b> 1 extends / retracts the counterweight 6 that supports the front attachment 3 from behind via the mast 4, the guy line 10 that connects the counterweight 6 and the mast 4, and the counterweight 6 and the upper swing body 2. And a possible elastic member 7.

  In the crane X1, the counterweight 6 that travels on the ground G behind the upper swing body 2 is connected to the tip of the mast 4 via the guy line 10, and the front attachment 3 and the counterweight 6 maintain the balance, The front attachment 3 is prevented from falling forward. At this time, the expansion member 7 expands and contracts in accordance with, for example, the weight of the front attachment 3 or the undulation angle with respect to the ground G, so that the upper swing body 2 is stably kept in balance with the front attachment 3 and the counterweight 6. And the counterweight 6 are changed.

  The counterweight 6 is disposed behind the upper swing body 2. The counterweight 6 includes a weight body 61, a wheel 62 that can roll on the ground G, and a reaction force detector 63 that detects a reaction force received by the wheel 62 from the ground G.

  The weight main body 61 has a weight that allows the counterweight 6 to keep balance with the front attachment 3. The weight main body 61 is connected to the tip of the mast 4 via the guy line 10. The weight main body 61 generates a driving force for changing the direction of the wheel 62 in accordance with, for example, a signal transmitted from the upper swing body 2 or for rolling the wheel 62 in a predetermined direction.

  The wheels 62 are attached to the lower part of the weight body 61 so that the weight body 61 can travel on the ground G. In the present embodiment, the wheel 62 travels on the ground G by receiving the driving force from the weight main body 61.

  The reaction force detector 63 is attached to the weight body 61 in order to determine whether or not the wheel 62 can travel on the ground G, that is, whether or not the wheel 62 is in contact with the ground G. It has been. The reaction force detector 63 detects a reaction force that the wheel 62 receives from the ground G based on, for example, a change in pressure inside the tire that constitutes the wheel 62.

  The elastic member 7 connects the upper swing body 2 and the weight main body 61 of the counterweight 6. Specifically, the elastic member 7 connects the rear end of the upper swing body 2 and the weight main body 61. The telescopic member 7 is configured to be able to expand and contract between the shortest length L1 and the longest length L2 upon receiving a driving force from the counterweight 6 that runs on the ground G. In FIG. 1, the telescopic member 7 is set to the longest length L <b> 2, whereby the counterweight 6 is disposed at the rear end position E <b> 4 where the separation distance from the upper swing body 2 is farthest.

  Here, as shown in FIG. 1 and FIG. 2, the crane X 1 detects the separation distance from the upper swing body 2 to the counter weight 6 according to the expansion / contraction of the expansion / contraction member 7, thereby determining the rear end position of the counter weight 6. A distance detector 8 to be identified and a rear end position control device 9 for changing the rear end position by expanding and contracting the telescopic member 7 are provided.

  The distance detector 8 is attached to the rear end of the upper swing body 2. The distance detector 8 detects a separation distance from the rear end of the upper swing body 2 to the counterweight 6. In the present embodiment, since the elastic member 7 connects the rear end of the upper swing body 2 and the counterweight 6, the separation distance detected by the distance detector 8 is the same as the length of the elastic member 7.

  As shown in FIG. 2, the rear end position control device 9 functionally includes an operation unit 91, an operation prohibition unit 92, a calculation unit 93, a measurement unit 94, and a contraction operation prohibition restriction unit 95. Yes. In addition, the function of each part 91-95 in the rear end position control apparatus 9 may be implement | achieved by an individual functional component, and may be implement | achieved by a common functional component.

  Below, each part 91-95 contained in the rear-end position control apparatus 9 is demonstrated concretely, referring FIG.

  The operation unit 91 performs an operation of changing the rear end position of the counterweight 6 in accordance with, for example, an input of a rear end position change switch provided in the cab of the upper swing body 2. Specifically, the operation unit 91 changes the direction of the wheel 62 along the longitudinal direction of the telescopic member 7 in accordance with the input of the rear end position change switch, and rolls the wheel 62 to make a counter. A rear end position intended for the counterweight 6 is transmitted by transmitting an expansion / contraction signal that causes the weight 6 to move forward or backward, and thereby expanding / contracting the expansion / contraction member 7 that receives the driving force from the counterweight 6 to a predetermined length. To move. In the present embodiment, as shown in FIG. 1, the operation unit 91 receives an input from the rear end position change switch and moves the counterweight 6 to one of the four rear end positions E1 to E4. Is transmitted to the operation prohibition unit 92 described later. For example, when a rear end position change switch for moving the counterweight 6 to the rear end position E3 is input, the operation unit 91 expands / contracts the telescopic member 7 to a predetermined length corresponding to the rear end position E3. A signal is transmitted to the operation prohibition unit 92.

  The operation prohibition unit 92 that has received the expansion / contraction signal from the operation unit 91 receives various types of information from the reaction force detector 63, the distance detector 8, the calculation unit 93, and the measurement unit 94. Based on the expansion / contraction signal, it is determined whether expansion / contraction of the expansion / contraction member 7 is permitted or prohibited. Specifically, the operation prohibition unit 92 transmits a signal for driving the counterweight 6 to the weight main body 61 when the received various information and the expansion / contraction signal satisfy a specific condition, thereby causing the operation unit 91 to The expansion / contraction operation is allowed, and when the received various information and the expansion / contraction signal do not satisfy a specific condition, the expansion / contraction operation of the operation unit is prohibited by invalidating the expansion / contraction signal. In more detail, it is as follows.

  The operation prohibition unit 92 receives reaction force information received from the ground G by the wheel 62 detected by the reaction force detector 63 of the counterweight 6 when receiving an expansion / contraction signal from the operation unit 91. When the reaction force received by the wheel 62 from the ground G is 0, the operation prohibiting unit 92 that has received the reaction force information is in a state in which the counterweight 6 cannot self-run due to the wheel 62 floating from the ground G. By determining and invalidating the expansion / contraction signal received from the operation unit, expansion / contraction of the expansion / contraction member 7 is prohibited. On the other hand, when the reaction force that the wheel 62 receives from the ground G exceeds 0, it is determined that the counterweight 6 is in a self-propellable state because the wheel 62 is in contact with the ground G.

  When the operation prohibition unit 92 determines that the counterweight 6 is in a self-propellable state, the operation prohibition unit 92 receives the separation distance information between the upper swing body 2 and the counterweight 6 detected by the distance detector 8, and the separation distance information Based on the above, the current rear end position of the counterweight 6 is specified. The operation prohibiting unit 92 that has identified the current rear end position moves the expansion / contraction member 7 from the current state based on the target rear end position and the current rear end position according to the expansion / contraction signal received from the operation unit 91. Determine whether to stretch or shrink.

  The operation prohibiting unit 92 that has determined that the telescopic member 7 should be stretched from the current state sends an extension signal for stretching the telescopic member 7 to the weight main body 61 until the counterweight 6 reaches the target rear end position. The telescopic member 7 receiving the driving force from the weight main body 61 extends to a predetermined length corresponding to the target rear end position.

  On the other hand, the operation prohibiting unit 92 that has determined that the telescopic member 7 should be contracted from the current state receives the estimation information of the rated total load of the crane X1 from the calculating unit 93 and the suspension load of the front attachment 3 from the measuring unit 94. The measurement information is received, and it is determined whether to allow or prohibit the contraction of the expansion / contraction member 7 based on the received estimated total load load information and suspension load measurement information.

  The calculation unit 93 receives a command from the operation prohibition unit 92 and calculates the rated total load of the front attachment 3. Specifically, the calculation unit 93 receives a command from the operation prohibition unit 92, and based on the undulation angle of the boom 31 with respect to the ground G when the operation prohibition unit 92 receives an expansion / contraction signal from the operation unit 91, The total rated load of the front attachment 3 when the counterweight 6 is at any one of the rear end positions E1 to E4 is estimated. And the estimated information of the rated total load in each rear end position E1-E4 is transmitted to the operation prohibition part 92.

  The measuring unit 94 receives a command from the operation prohibiting unit 92 and measures the suspension load on the front attachment 3. Specifically, the measurement unit 94 receives a command from the operation prohibition unit 92, measures the suspension load of the front attachment 3 when the operation prohibition unit 92 receives an expansion / contraction signal from the operation unit 91, and measures the measurement. The suspension load measurement information is transmitted to the operation prohibition unit 92. In the present embodiment, the suspended load includes the weight of the hanging tool 32 in addition to the weight of the suspended load suspended from the hook 32a.

  The operation prohibition unit 92 that has received the measurement information of the suspension load from the measurement unit 94 includes the current rear end position and the target rear end position among the rated total loads at the rear end positions E1 to E4 received from the calculation unit 93. Based on each of the rated total loads, when these satisfy a specific condition, a reduced signal for moving the counterweight 6 to the target rear end position is transmitted to the weight body 61, thereby On the other hand, the contraction operation for contracting the expansion / contraction member 7 to a predetermined length corresponding to the rear end position to be performed is allowed, but if the specific condition is not satisfied, the contraction operation is prohibited. When the contraction operation is prohibited, the operation prohibition unit 92 transmits the measurement information of the suspended load received from the measurement unit 94 and the contraction signal to the contraction operation prohibition restriction unit 95.

  When the suspension load measured by the measurement unit 94 is equal to or less than a preset allowable load, the contraction operation prohibition restriction unit 95 cancels the prohibition of the contraction operation by the operation prohibition unit 92 and allows the contraction operation. Here, the allowable load is set to the maximum suspended load when the hook 32a of the front attachment 3 is not substantially suspended from the suspended load. This allowable load is set based on the weight of the hanger 32. The allowable load is set larger than the weight of the hanger 32. The allowable load is set to, for example, twice the weight of the hook 32a. When the suspended load is equal to or less than the allowable load, it can be determined that the suspended load is not substantially suspended from the hook 32a.

  Upon receiving the suspension load measurement information and the contraction signal from the operation prohibition unit 92, the contraction operation prohibition restriction unit 95 compares the suspension load with the allowable load stored in advance in the contraction operation prohibition restriction unit 95. Only when it is determined that the load is less than or equal to the allowable load, the contraction signal is transmitted to the weight main body 61 so as to cancel the prohibition of the contraction operation by the operation prohibition unit 92, so that the predetermined length corresponding to the target rear end position is reached The elastic member 7 is contracted.

  Thus, in the crane X1, according to the expansion / contraction operation of the expansion / contraction member 7 in the operation unit 91, it is determined whether the operation prohibition unit 92 permits or prohibits the expansion / contraction operation. The operation prohibiting unit 92 allows the extension member 7 to be extended when it is necessary to extend the extension member 7 when moving the counterweight 6 from the current rear end position to the target rear end position. When the expansion member 7 needs to be contracted, the contraction operation of the expansion member 7 is allowed when a specific condition is satisfied, while the contraction operation is prohibited when the specific condition is not satisfied. When the operation prohibition unit 92 prohibits the contraction operation, the contraction operation prohibition restriction unit 95 determines whether or not the suspended load is substantially suspended from the hook 32a, and determines that the suspended load is not suspended. Only when it is done, the prohibition of the contraction operation is released, and the contraction operation of the telescopic member 7 is allowed.

  Next, in the above-described crane X1, with respect to the removal method for removing the telescopic member 7 from the upper swing body 2 and the counterweight 6 after the telescopic member 7 is contracted to a predetermined length, the telescopic member 7 shown in FIG. This will be described with reference to a flowchart.

  The elastic member 7 is detached from the upper swing body 2 and the counterweight 6 by the following removal method. In addition, below, only the main processes are demonstrated among the removal methods of the expansion-contraction member 7 of the crane X1 which concerns on this embodiment. Therefore, the removal method of the expansion-contraction member 7 of the crane X1 according to the present embodiment may include an arbitrary step that is omitted in this specification.

  First, the expansion / contraction operation of the expansion / contraction member 7 is performed. Specifically, when an operator of the crane X1 inputs a rear end position change switch in the cab of the upper swing body 2, an expansion / contraction signal corresponding to the input is transmitted from the operation unit 91 to the operation prohibition unit 92. (Yes in step ST1). In the present embodiment, in the state where the counter weight 6 is disposed at the rear end position E3, an expansion / contraction signal for moving the counter weight 6 to the rear end position E2 is operated by inputting a rear end position change switch. It is assumed that data is transmitted from the unit 91 to the operation prohibition unit 92.

  Next, it is determined whether or not the expansion / contraction member 7 is extendable / contractible in the current crane X1. Specifically, it is as follows.

  The operation prohibition unit 92 that has received the expansion / contraction signal for moving the counterweight 6 to the target rear end position from the operation unit 91 sends a command to the calculation unit 93 so as to calculate the rated total load of the crane X1. Upon receiving the command, the calculation unit 93 calculates the rated total load when the counterweight 6 is positioned at each of the rear end positions E1 to E4 based on the inclination angle of the boom 31 with respect to the ground G in the current crane X1. Estimate. The calculation unit 93 that has estimated the rated total load at each of the rear end positions E1 to E4 transmits the estimation result to the operation prohibition unit 92. The operation prohibition unit 92 that has received the estimation result determines whether or not all the rated total loads at the respective rear end positions E1 to E4 are 0 (step ST2). When the rated total load at each of the rear end positions E1 to E4 is 0, the operation prohibiting unit 92 determines that the crane X1 does not have the lifting ability, invalidates the expansion / contraction signal received from the operating unit 91, and performs step ST1. (No in step ST2). On the other hand, when at least one of the rated total loads at each of the rear end positions E1 to E4 exceeds 0, the process proceeds to the next step ST3 (Yes in step ST2).

  In step ST2, the operation prohibiting unit 92, which has determined that at least one rated total load among the rated total loads at each of the rear end positions E1 to E4 exceeds 0, indicates that the wheel 62 is grounded with respect to the reaction force detector 63. A command is sent to detect the reaction force received from G. Receiving the command, the reaction force detector 63 detects the reaction force and transmits information on the reaction force to the operation prohibiting unit 92. Then, the operation prohibition unit 92 that has received the reaction force information from the reaction force detector 63 determines whether or not the reaction force is 0 (step ST3). When the reaction force is 0, the operation prohibition unit 92 determines that the counterweight 6 is in a self-propelled state because the wheel 62 is floating from the ground G, and invalidates the expansion / contraction signal received from the operation unit 91. And return to step ST1 (No in step ST3). On the other hand, when the reaction force exceeds 0, it is determined that the expandable member 7 can be expanded and contracted, and the process proceeds to the next step ST4 (Yes in step ST3).

  Next, it is determined whether the expansion / contraction operation in the expansion / contraction operation step is an expansion operation for extending the expansion / contraction member 7 or a contraction operation for contracting the expansion / contraction member 7. Specifically, it is as follows.

  The operation prohibiting unit 92 that determines that the reaction force that the wheel 62 receives from the ground G exceeds 0 in step ST <b> 3 detects the separation distance from the upper swing body 2 to the counterweight 6 with respect to the distance detector 8. Send a command. The distance detector 8 that has received the command detects the separation distance and transmits the detection information to the distance detector 8. Then, the operation prohibition unit 92 that has received the detection information of the separation distance from the distance detector 8 specifies which rear end position E1 to E4 the current counterweight 6 is arranged based on the separation distance. . In the present embodiment, the operation prohibition unit 92 receives the information on the separation distance from the distance detector 8 and specifies that the current counterweight 6 is disposed at the rear end position E3.

  The operation prohibition unit 92 that has specified the current rear end position of the counterweight 6 is based on the current rear end position and the target rear end position specified based on the expansion / contraction signal received from the operation unit 91. Then, it is determined whether the expansion / contraction signal is an expansion signal for extending the expansion / contraction member 7 or a contraction signal for contracting the expansion / contraction member 7 (step ST4). In the present embodiment, the current counterweight 6 is disposed at the rear end position E3, and the counterweight 6 is moved to the rear end position E2. This is a contraction signal for contracting the telescopic member 7, and the process proceeds to step ST5 (Yes in step ST4). If the counter weight 6 is moved to the rear end position E4, the expansion / contraction signal received by the operation prohibition unit 92 from the operation unit 91 is an expansion signal for extending the expansion / contraction member 7 (No in step ST4). Then, the operation prohibiting section 92 sends the extension signal to the weight main body 61, thereby moving the counterweight 6 to the target rear end position E4 while extending the telescopic member 7 (step ST7).

  The operation prohibition unit 92 that has determined that the expansion / contraction operation in the operation unit 91 is a contraction operation for contracting the expansion / contraction member 7 in step ST4 is included in the rated total loads at the rear end positions E1 to E4 received from the calculation unit 93. Then, it is determined whether or not the rated total load at the target rear end position is 0 (step ST5). In the present embodiment, the operation prohibiting unit 92 determines whether or not the rated total load at the rear end position E2 is zero.

  When the rated total load at the target rear end position in step ST5 exceeds 0 (Yes in step ST5), the operation prohibiting unit 92 transmits the contracted signal received from the operating unit 91 to the weight main body 61. Thus, the contraction operation is allowed, and thereby the telescopic member 7 is contracted and the counterweight 6 is moved to the target rear end position (step ST6).

  On the other hand, when the rated total load at the target rear end position is 0 (No in step ST5), the operation prohibiting unit 92 invalidates the contraction signal received from the operation unit 91 and contracts the telescopic member 7. Ban. Specifically, the operation prohibition unit 92 transmits the contracted signal received from the operation unit 91 to the contraction operation prohibition limiting unit 95 without transmitting it to the weight main body 61. Thereby, when it determines with No in step ST5, the said shrinking operation will be prohibited once.

  The contraction operation prohibition limiting unit 95 that has received the contraction signal from the operation prohibition unit 92 sends a command to the measurement unit 94 to measure the suspension load in the front attachment 3. The measurement unit 94 that has received the command measures the suspension load and transmits the measurement information to the operation prohibition unit 92.

  The contraction operation prohibition restriction unit 95 that has received the measurement information of the suspension load from the measurement unit 94 compares the suspension load in the front attachment 3 with the allowable load stored in advance in the contraction operation prohibition restriction unit 95 (step ST7).

  Based on the measurement information of the suspension load received from the operation prohibition unit 92, the contraction operation prohibition restriction unit 95 that determines that the suspension load is less than the allowable load (Yes in step ST7) is substantially suspended from the hook 32a. It is judged that the load is not hung, and the prohibition of the contraction operation is canceled, and the contraction signal received from the operation prohibition unit 92 is transmitted to the weight main body 61, so that the counterweight 6 is targeted while the contracting member 7 is contracted. Move to the rear end position (step ST6).

  On the other hand, the contraction operation prohibition limiting unit 95 that has determined that the suspension load is greater than or equal to the allowable load based on the measurement information of the suspension load received from the operation prohibition unit 92 (No in step ST7) is substantially applied to the hook 32a. It is determined that the suspended load is suspended, and the prohibition of the shrinking operation is continued (step ST8). That is, when it is determined No in step ST7, the contraction operation prohibition limiting unit 95 invalidates the contraction signal received from the operation prohibition unit 92 and completely prohibits the contraction of the telescopic member 7.

  As described above, in this embodiment, the counterweight 6 is safely moved from the rear end position E3 to the rear end position E2 by allowing the contraction operation through the above-described steps, and accordingly, the telescopic member 7 is moved. Reduce the length of. Then, by repeating this step, the counterweight 6 is safely moved to the rear end position E1, and thereby the elastic member 7 is shortened to the shortest length L1.

  In addition, when it becomes necessary to prohibit the shrinking operation in the middle of the above step, for example, after changing the hoisting angle of the boom 31 with respect to the ground G, or lowering the suspended load suspended from the hook 32a, Repeat the above steps again. Thereby, the counterweight 6 is safely moved to the rear end position E1, and the elastic member 7 is shortened to the shortest length L1.

  Then, by repeating the above steps, the elastic member 7 is shortened to the shortest length L1, and then the elastic member 7 is removed from the counterweight 6 and the upper swing body 2.

  As described above, the telescopic member 7 can be removed from the crane X1 after the telescopic member 7 is contracted to the shortest length.

  Thus, in the crane X1 which concerns on this embodiment, the expansion-contraction member 7 can be shortened to predetermined length, ensuring safety | security. Specifically, it is as follows.

  In the crane X1, when the contracting operation for contracting the telescopic member 7 to a predetermined length is performed in the operation unit 91, the operation prohibiting unit 92 allows the contracting operation when the rated total load calculated by the calculating unit 93 exceeds zero. On the other hand, when the rated total load is 0, the shrinking operation is prohibited. Thereby, the expansion-contraction member 7 can be shortened to predetermined length only in the state in which the safety | security of the crane X1 was ensured because the rated total load exceeded zero.

  By the way, even if the rated total load when the telescopic member 7 is contracted to a predetermined length is 0, when the front attachment 3 is in a state of not substantially hanging a suspended load, while ensuring safety. The elastic member 7 can be shortened to a predetermined length.

  Therefore, the contraction operation prohibition restriction unit 95 cancels the prohibition of the contraction operation and allows the contraction operation when the suspension load measured by the measurement unit 94 is equal to or less than the allowable load. As a result, even if the total rated load when the stretchable member 7 reaches a predetermined length is 0, the contraction operation is allowed when the front attachment 3 is not substantially suspended from the suspended load. The elastic member 7 is contracted to a predetermined length. For this reason, the elastic member 7 can be shortened to a predetermined length while ensuring safety.

  Further, in the crane X1 according to the present embodiment, the suspension load includes the weight of the suspension tool, and the allowable load is set to a value exceeding the weight of the suspension tool. It is possible to more accurately determine whether or not the suspended load is substantially suspended, and thereby the elastic member 7 can be shortened to a predetermined length while ensuring safety.

  Moreover, in the removal method of the expansion / contraction member 7 of the crane X1 which concerns on this embodiment, the expansion / contraction member 7 can be shrunk | removed and removed to predetermined | prescribed length, ensuring safety | security. Specifically, it is as follows.

  In the method of removing the telescopic member 7 of the crane X1, the operation prohibiting unit 92 allows the contracting operation when the rated total load calculated by the calculating unit 93 exceeds 0, while the rated total load is 0. The shrink operation is prohibited.

  Therefore, in the method of removing the telescopic member 7 of the crane X1, the suspension load on the front attachment 3 is measured in the measurement step, and the prohibition of the contraction operation is canceled only when the suspension load is equal to or less than the allowable load, and the contraction operation is performed. Allow. Thereby, even if the rated total load is 0 when the elastic member 7 reaches a predetermined length, if the front attachment 3 is not in a substantially suspended state, the elastic member 7 is reduced to the predetermined length. Can be shortened. For this reason, the elastic member 7 can be retracted to a predetermined length and removed while ensuring safety.

  The above-described embodiment described above should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

  For example, the counterweight of the crane according to the present invention may be connected to the front attachment 3 so as to be balanced with the front attachment 3, and the shape and structure thereof are not particularly limited. In the above-described embodiment, the counterweight 6 has the wheels 62 and travels by the wheels 62 rolling on the ground G, but is not limited thereto. The counterweight 6 may not have the wheels 62, for example, and may be fixed to the upper swing body 2 via the elastic member 7 in a state of floating from the ground G. In this case, whether or not the expansion / contraction member 7 in step ST3 in the flowchart shown in FIG. If the expansion / contraction member 7 is floating from the ground G, it is determined that the expansion / contraction member 7 is in an expandable / contractible state, and the process proceeds to step ST4. If the expansion / contraction member 7 is in contact with the ground G, the expansion / contraction member 7 is expanded / contracted. Returning to step ST1 because it is impossible.

  Moreover, the expansion-contraction member of the crane which concerns on this invention should just be comprised so that it may expand-contract with the driving force of a body or a counterweight. In the above embodiment, the expansion and contraction member 7 expands and contracts by the driving force of the counterweight 6, but is not limited thereto. For example, the expansion / contraction member 7 may be configured to expand and contract by a driving force from the upper swing body 2. In this case, the counterweight 6 may not be configured to be able to run on its own.

  Further, the allowable load set in advance in the crane according to the present invention may be a value similar to the maximum suspended load when the front attachment is not substantially suspended from the suspended load. It may be set. In the present embodiment, the allowable load is set based on the weight of the hanger 32, but is not limited thereto. For example, the allowable load may be set to a value twice the weight of the hook 32a based only on the weight of the hook 32a in the hanging tool 32.

  Further, the contraction operation prohibition unit of the crane according to the present invention may permit or prohibit the contraction operation in the operation unit depending on whether or not the rated total load calculated in the calculation unit exceeds a predetermined value. It may be set to a value at which it can be determined that the crane does not have a lifting capacity. In this embodiment, the operation prohibiting unit 92 allows or prohibits the contraction operation depending on whether or not the rated total load calculated by the calculating unit 93 is 0. Therefore, the predetermined value is set to 0. Not limited to this. The predetermined value may be set to a value slightly larger than 0, for example.

  Moreover, the predetermined length of the telescopic member in the crane according to the present invention may not be set in advance, and the operator can freely determine between the longest length and the shortest length. In the present embodiment, it is set in advance that the counterweight 6 is disposed only at any one of the rear end positions E1 to E4. According to this, the predetermined length is also set to four. Not exclusively. For example, the counter weight 6 may be disposed at a position between each of the rear end positions E1 to E4, and the rear end position at which the counter weight 6 is disposed may not be set in advance.

  Further, the rear end position of the counterweight 6 may be determined by any means. In the above embodiment, the rear end position of the counterweight 6 is determined based on the separation distance between the upper swing body 2 and the counterweight 6 detected by the distance detector 8, but the present invention is not limited to this. For example, when the rear end position of the counterweight 6 is arranged at any one of the rear end positions E1 to E4 as in the present embodiment, the counterweight 6 is set to any one of the rear end positions E1 to E4. The telescopic member 7 may be provided with a signal sending unit so that the rear end position of the counterweight 6 can be determined by sending a signal from the telescopic member 7 to the operation prohibiting unit 92 at a later stage.

  Moreover, in the removal method of the expansion-contraction member of the crane which concerns on this invention, each of a measurement process, a shrinking operation permission process, and a removal process may be performed mechanically or may be performed manually. In the above embodiment, step ST7 for determining whether or not the suspension load measured in the measurement process exceeds the allowable load is performed by the contraction operation prohibition limiting unit 95, but is not limited thereto. For example, the suspension load measured in the measurement process may be displayed on a monitor mounted in the cab of the upper swing body 2, and the operator may determine whether the suspension load exceeds the allowable load based on the display. . In this case, an operator who has determined that the suspension load does not exceed the allowable load, for example, by inputting a contraction operation prohibition release switch mounted in the cab, cancels the prohibition of the contraction operation and allows the contraction operation. To do. According to such a method, the contraction operation prohibition limiting unit 95 becomes unnecessary.

  In the present embodiment, the main body that determines whether to permit or prohibit the shrinking operation in each of steps ST6 and ST10 is the operation prohibiting unit 92, but is not limited thereto. For example, the operation prohibiting portion 92 prohibits the telescopic member 7 from contracting so that the counterweight 6 moves to the rear end position where the rated total load becomes 0, and the monitor mounted in the cab of the upper swing body 2 The suspension load measured in the measurement process and the rated total load calculated in the calculation unit are displayed, and based on the display, the worker may cancel the prohibition only when the safety of the crane X1 is ensured. . In this case, the worker who has determined that the safety of the crane X1 is secured, for example, by inputting a contraction operation prohibition release switch mounted in the cab, cancels the contraction operation prohibition and performs the contraction operation. Allow.

X1 Crane 1 Lower traveling body (airframe)
2 Upper swing body (airframe)
3 Front Attachment 6 Counterweight 7 Stretchable Member 32 Lifting Tool 91 Operation Unit 92 Operation Prohibited Unit (Shrinking Operation Prohibited Unit, Overload Judgment Unit)
93 Calculation unit 94 Measurement unit 95 Reduction operation prohibition restriction unit

Claims (4)

The aircraft,
A front attachment that is attached to the aircraft so as to be able to undulate in front of the aircraft and can suspend suspended loads;
A counterweight disposed behind the aircraft and connected to the front attachment so as to be balanced with the front attachment;
A telescopic member that connects the machine body and the counterweight and can be expanded and contracted so as to change a separation distance between the machine body and the counterweight;
An operation unit that performs a contracting operation to contract the expansion / contraction member to a predetermined length between the longest length of the expansion / contraction member and the shortest length of the expansion / contraction member by a driving force from the machine body or the counterweight;
A calculating unit that calculates a rated total load of the front attachment at the predetermined length based on a posture of the front attachment;
When the rated total load calculated in the calculation unit exceeds a predetermined value, the contraction operation in the operation unit is allowed, while the rated total load calculated in the calculation unit is equal to or less than a predetermined value. A contraction operation prohibition unit that prohibits the contraction operation in the operation unit;
A measurement unit for measuring a suspended load in the front attachment;
A contraction operation prohibition control unit for canceling the prohibition of the contraction operation by the contraction operation prohibition unit and allowing the contraction operation when the suspension load measured in the measurement unit is equal to or less than a preset allowable load; Crane with. The front attachment has a hanging tool for hanging the suspended load,
The suspension load measured in the measurement unit includes the weight of the suspension tool,
The crane according to claim 1, wherein the allowable load set in advance in the contraction operation prohibition control unit is set to a value exceeding the weight of the hoisting tool. A balance is established between the airframe, a front attachment that is attached to the airframe so as to be able to undulate in front of the airframe, and can suspend a suspended load, and is disposed behind the airframe and the front attachment. A counterweight connected to the front attachment, an extendable / contractible member for connecting the machine body and the counterweight and changing a separation distance between the machine body and the counterweight, and the machine body or the counterweight. An operating portion that performs a contracting operation to contract the expansion / contraction member to a predetermined length between the longest length and the shortest length by a driving force, and a rated total load of the front attachment at the predetermined length based on a posture of the front attachment. Calculation unit for calculating, and calculation When the total rated load calculated in step S1 exceeds a predetermined value, the contraction operation in the operation unit is permitted, while in the operation unit when the total rated load calculated in the calculation unit is equal to or less than a predetermined value. A method for removing the contraction member after contracting to the predetermined length in a crane including a contraction operation prohibition unit that prohibits the contraction operation;
A measuring step for measuring a suspended load in the front attachment;
When the suspension load measured in the measurement step is compared with a preset allowable load and it is determined that the suspension load measured in the measurement step is equal to or less than the allowable load, the reduction operation by the reduction operation prohibiting unit is performed. A contraction operation permission step for canceling the prohibition of operation and allowing the contraction operation;
A method for removing the telescopic member of the crane, comprising: removing the telescopic member from the machine body and the counterweight after the telescopic member is contracted to the predetermined length. The front attachment has a hanging tool for hanging the suspended load,
In the measuring step, the suspension load including the weight of the suspension tool is measured,
The method according to claim 3, wherein, in the contraction operation permission step, the suspension load measured in the measurement step is compared with the allowable load set to a value exceeding the weight of the suspension tool. .

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