JP2012131635A - Crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically stop an engine when an attachment is in a safe state.SOLUTION: A controller 75 (engine control means) stops the engine 51 (step S5), when a state where a sensor 71 (actuator operation detecting means) detects that none of plurality of actuators 60 is operated continues for a given time (step S2 and step S3), and when a load detected by a load detection means 72 is smaller than the empty weight of the attachment 30 (step S4).

Description

  The present invention relates to a crane that stops an engine when a predetermined condition is satisfied.

  Conventionally, there is a crane having an idling stop function (for example, Patent Document 1). In this type of crane, the engine is automatically stopped when a predetermined condition is satisfied, thereby reducing the fuel consumption of the crane, reducing exhaust and noise, and the like.

  In the technique disclosed in Patent Document 1, the engine is stopped when “the state where there is no crane operation” and “the state where there is no suspended load” continue for a preset time at the same time (the state where there is no accelerator operation) In some cases).

  In the above technique, the state where there is no suspended load is the condition for the automatic stop of the engine. Thereby, the danger that an engine stops automatically in the state which suspended the suspended load is avoided. In the above technique, “the state where there is no suspended load” is a state where the lifting load applied to the tip of the boom is the same as the weight of the hanging load hook (see paragraph 0015 of Patent Document 1). The hook is one of various types of attachments (details will be described later).

JP 2006-62782 A

  With the technique described in Patent Document 1, there is a risk that the engine will automatically stop despite the possibility of the attachment being beaten.

  More specifically, an attachment suspended from a boom (not landing) may be beaten by, for example, wind. In particular, in a crane that performs work at a high place, such as a tower crane, the attachment may be greatly beaten. If there is an operator around the beaten attachment, the attachment may pose a danger to the operator. In order to avoid this danger, it is conceivable to perform operations such as turning the crane, hoisting or lowering the attachment. However, in the above technique, even when the attachment is suspended from the boom (not landing or the like), the engine may automatically stop while satisfying the predetermined condition. When the engine is automatically stopped, an operation for avoiding the above danger cannot be performed quickly.

  Further, with the technique described in Patent Document 1, there is a risk that the engine will automatically stop despite the attachment being in a free fall state.

  More specifically, in the above technique, a state where there is no crane operation is set as one of the conditions for stopping the engine. The “state where there is no crane operation” in the above technique is a state where there is no operation of crane operation means (specifically, an operation lever) (see claim 1 and paragraph 0016 of Patent Document 1). The crane operating means is operated when the actuator is driven using the engine as a power source (see the same part).

  Here, the attachment may be in a free fall state (details will be described later). In this case, the crane operating means is not operated (the operating lever is in the neutral state). At this time, the above technique satisfies the condition of “no crane operation”. Further, when other conditions are also satisfied, the engine automatically stops despite the attachment being in the free fall state. In particular, when the attachment is brought into a free-fall state from a state where the attachment head is high, the state in which the crane operating means is not operated continues for a relatively long time, so that the condition of “when the preset time is continued” of the above technique is satisfied. As a result, the engine may automatically stop in a free fall state.

  Then, an object of this invention is to provide the crane which can perform an engine automatic stop when an attachment is a safe state.

Means and effects for solving the problems

A crane according to a first aspect of the present invention includes a crane body, an engine provided in the crane body, a plurality of actuators driven by using the engine as a power source, a boom attached to the crane body, and the plurality of actuators An attachment that is suspended from the boom via a hoisting rope wound around some of the actuators, an actuator operation detecting means that detects whether or not the plurality of actuators are moving, and a load on the attachment is detected Load detecting means for controlling the engine, and engine control means for controlling the engine. In the engine control means, a state in which the actuator operation detecting means detects that none of the plurality of actuators is moving continues for a predetermined time, and the load detected by the load detecting means is the weight of the attachment. If it is smaller, the engine is stopped.
“Actuator is moving” means not only the state where the actuator is driven with the engine as a power source, but also that the actuator is operated without using the engine as a power source, as in the case of the attachment in a free fall state. Including the state.

This crane includes an attachment that is suspended from a boom via a hoisting rope wound around some of the plurality of actuators. Further, “the actuator operation detection means detects that none of the plurality of actuators is moving” is included in the engine stop condition by the engine control means. When this condition is satisfied, the actuator wound with the hoisting rope does not move, so the attachment suspended from the boom via the hoisting rope does not move. That is, when this condition is satisfied, the attachment is not in a free fall state (state A).
The crane also includes load detection means for detecting the load on the attachment. Further, “the load detected by the load detection means is smaller than the weight of the attachment” is included in the engine stop condition by the engine control means. When this condition is satisfied, the attachment head is in a state of 0, so the attachment is not beaten (state B).
In this crane, the engine control means stops the engine when the above state A and state B are satisfied. Therefore, the engine can be automatically stopped when the attachment is in a safe state.

  A crane according to a second aspect of the present invention includes attachment weight setting means for setting the weight of the attachment.

  In this crane, even when the specification of the attachment is changed, the first invention can be reliably implemented by setting the weight of the attachment with the attachment weight setting means.

1 is an overall view of a crane. It is a block diagram around the engine control means with which the crane shown in FIG. 1 is provided. It is a flowchart of operation | movement of the engine control means shown in FIG.

Hereinafter, an embodiment of the crane 1 will be described with reference to FIGS. 1 to 3.
As shown in FIG. 1, the crane 1 is a hydraulic mobile crane, and specifically, for example, a lattice boom crawler crane (LBCC). The crane 1 has a function (idling stop function) that automatically stops the engine 51 when a predetermined condition is satisfied. The crane 1 includes a crane body 10, a boom 20 attached to the crane body 10, an attachment 30 suspended from the boom 20, and a gantry 40 attached to the crane body 10. As shown in FIG. 2, the crane 1 includes an engine 51 provided in the crane body 10 (see FIG. 1), a hydraulic pump 52 driven by the engine 51, and a control valve 53 connected to the hydraulic pump 52. And a plurality of actuators 60 (only one is shown in FIG. 2) connected to the control valve 53, and a controller 75 (engine control means) for controlling the engine 51. Furthermore, the crane 1 (see FIG. 1) includes a sensor 71 (actuator operation detection means), a load detection means 72, and an attachment weight setting means 73, which are connected to the controller 75, respectively.

  As shown in FIG. 1, the crane body 10 includes a lower body 11 and an upper body 13 attached above the lower body 11. The lower main body 11 is, for example, a crawler type traveling body (may be a wheel type traveling body). The upper main body 13 is attached to the upper side of the lower main body 11 via a swivel bearing 12 and can be swiveled with respect to the lower main body 11.

  The boom 20 is attached to the crane body 10. The boom 20 is a member that suspends the attachment 30 via the hoisting rope 25, and is, for example, a lattice boom (a box-type telescopic boom may be used). The boom 20 is attached to the front end portion of the upper body 13 so as to be raised and lowered. A supplementary jib (not shown) may be attached to the tip of the boom 20. The boom 20 includes a boom sheave 21 at the tip.

  The boom sheave 21 is a pulley for passing and winding the winding rope 25, and a plurality of boom sheaves 21 are provided on the boom 20. The plurality of boom sheaves 21 include an idler sheave 22 disposed on the back surface of the boom 20 and a point sheave 23 disposed on the front surface side of the tip of the boom 20.

  The hoisting rope 25 is a wire for hoisting and lowering the attachment 30. One end side of the hoisting rope 25 is wound around a winch drum 61d (see FIG. 2) of a winch assembly 61 (a part of a plurality of actuators 60). The other end of the hoisting rope 25 is hung between a sheave (not shown) included in the attachment 30 and the point sheave 23 (the portion of the hoisting rope 25 that is suspended from the point sheave 23 is referred to as “the hoisting rope”). 25a "). The hoisting rope 25 is stretched over the idler sheave 22.

  The attachment 30 is a member that is suspended from the boom 20 via the hoisting rope 25 (25a). The attachment 30 includes a hook for hanging a suspended load for crane work, an attachment for civil engineering work (not shown), and the like. There are various types of hooks according to the lifting capacity of the crane 1 and the like. Examples of the attachment for civil engineering work include a vibratory hammer and a clamshell bucket.

  This attachment 30 is wound up and down. That is, the lifting height 25 of the attachment 30 is changed by the winding rope 25 being wound and unwound by the winch assembly 61. The head H of the attachment 30 is a height (amount of change) from the reference plane D immediately below the attachment 30 to the lower end of the attachment 30. Specifically, the reference plane D is the ground (ground or underground), the sea surface, and the like. In addition, the reference plane D1 and the lift H1 when the ground directly under the attachment 30 is in the basement (below the lower main body 11) are indicated by a two-dot chain line in FIG.

  The gantry 40 is a member for raising and lowering the boom 20, and is configured by a box-shaped structure, for example. The gantry 40 is disposed on the rear side of the boom 20 and is attached to the crane body 10. The tip of the gantry 40 and the tip of the boom 20 are connected by a hoisting rope 45 and a guy line 46. A gantry sheave 41 is provided at the tip of the gantry 40 to hang the hoisting rope 45. Then, the boom 20 is raised and lowered by winding and unwinding the hoisting rope 45 with the hoisting winch assembly 62 (a part of the plurality of actuators 60). The configuration for raising and lowering the boom 20 may be modified to other configurations.

  The engine 51 (see FIG. 2) is a power source for the plurality of actuators 60 and is installed in the crane body 10. As shown in FIG. 2, the engine 51 drives a hydraulic pump 52. The hydraulic pump 52 supplies (discharges) hydraulic oil to the actuator 60 via the control valve 53.

  The control valve 53 controls the flow rate of hydraulic oil supplied from the hydraulic pump 52 to a plurality of actuators 60 (only one is shown in FIG. 2). The control valve 53 operates in response to an operation of a crane operation means (such as an operation lever) not shown. That is, the plurality of actuators 60 are operated in accordance with the operation of the crane operation means.

  The plurality of actuators 60 are hydraulic actuators that are driven using the engine 51 as a power source. As shown in FIG. 1, a plurality of actuators 60 include, for example, a winch assembly 61, a hoisting winch assembly 62, a hydraulic motor for turning the upper body 13 (not shown), and a hydraulic pressure for traveling the lower body 11. There is a motor (not shown).

  The winch assembly 61 (a part of the plurality of actuators 60) is an actuator that winds and unwinds the hoisting rope 25. The winch assembly 61 is disposed, for example, on the upper body 13 (may be disposed on the boom 20). As shown in FIG. 2, the winch assembly 61 includes a hydraulic motor 61m (winding motor) and a winch drum 61d (winding drum) connectable to the hydraulic motor 61m. The hydraulic motor 61m is driven by hydraulic fluid discharged from the hydraulic pump 52. A winding rope 25 (see FIG. 1) is wound around the winch drum 61d.

The winch assembly 61 operates as follows.
When the hydraulic motor 61m is driven in a state where the hydraulic motor 61m and the winch drum 61d are connected, the winch drum 61d rotates. As a result, the hoisting rope 25 (see FIG. 1) wound around the winch drum 61d is wound and unwound.
Further, when the connection between the hydraulic motor 61m and the winch drum 61d is disconnected, the winch drum 61d is freely rotatable. At this time, when the head H of the attachment 30 shown in FIG. 1 is not 0, the attachment 30 enters a free fall state (free fall). That is, the winch assembly 61 (actuator 60) is moving without using the power of the engine 51 (power of the hydraulic motor 61m) shown in FIG.

  The hoisting winch assembly 62 (actuator) is an actuator for winding and unwinding the hoisting rope 45 as shown in FIG. The hoisting winch assembly 62 includes a hydraulic motor (boom motor, not shown) and a winch drum (boom drum, not shown) connected to the hydraulic motor. The hoisting winch assembly 62 for undulation is disposed, for example, on the upper body 13 (may be attached to the gantry 40).

  The sensor 71 (actuator operation detection means) is a device that detects whether or not a plurality of actuators 60 are moving, as shown in FIG. The sensor 71 detects for each of the plurality of actuators 60 whether or not the actuator 60 is moving relative to the crane body 10 (see FIG. 1). Each of the plurality of sensors 71 is connected to the controller 75 and outputs a detection result to the controller 75 (only one of the plurality of sensors 71 is shown in FIG. 2). The sensor 71 detects the rotation of the winch drum 61 d when the actuator 60 is the winch assembly 61. The sensor 71 in this case is, for example, a proximity sensor (rotation sensor) that detects the rotation of the winch drum 61d in a non-contact manner.

The “actuator 60 is moving” state detected by the sensor 71 is not only the state in which the actuator 60 is driven with the engine 51 as a power source, but also the actuator 60 is operated without using the engine 51 as a power source. Including state. Specifically, when the actuator 60 is a winch assembly 61, the hydraulic motor 61m is not driven but the winch drum 61d is rotating, that is, when the attachment 30 shown in FIG. The assembly 61 is in a moving state.
It should be noted that an actuator 60 (for example, a hoisting winch assembly 62, a turning or traveling actuator, etc.) that does not move unless a crane operating means (such as an operating lever) is operated during the operation of the crane 1 The presence or absence of an operation signal output from the operation means may be detected, and as a result, it may be detected whether or not the actuator 60 is moving.

  The load detection means 72 (refer FIG. 2) detects the load of the attachment 30 (refer FIG. 1). As shown in FIG. 2, the load detection unit 72 is connected to the controller 75 and outputs the detected load to the controller 75. For example, the load detection means 72 includes a device that detects the tension of the hoisting rope 25 illustrated in FIG. 1, and specifically includes, for example, a load cell provided on the idler sheave 22. Further, for example, the load detection means 72 (see FIG. 2) includes a device that detects the tension of the hoisting rope 45 and the guy line 46, and specifically includes, for example, a load cell provided in the gantry sheave 41. The load of the attachment 30 detected by the load detecting means 72 (see FIG. 2) is obtained by subtracting the load due to the weight of the rope (the load of the hoisting rope 25a, etc.) from the tension detected by the load cell or the like. Value. However, when the load due to the weight of the rope is sufficiently smaller than the load of the attachment 30, the load due to the weight of the rope may be ignored.

  The attachment weight setting means 73 sets “the weight of the attachment 30 (see FIG. 1)”. As shown in FIG. 2, the attachment weight setting means 73 is connected to the controller 75 and sets (sets) the weight of the attachment 30 (see FIG. 1) in the controller 75. The attachment weight setting means 73 is used as follows, for example. When changing the specifications of the attachment 30 shown in FIG. 1 (before work), the changed attachment 30 is lifted from the boom 20 (the lift H is greater than 0). In this state, the load of the attachment 30 after the change is detected by the load detection means 72 shown in FIG. The load detection means 72 outputs the detection result to the attachment weight setting means 73. The attachment weight setting means 73 sets the weight of the attachment 30 in the controller 75 based on the input detection result. The attachment weight setting means 73 may be a device that sets the weight of the attachment 30 manually input in the controller 75.

  The controller 75 (engine control means) is a device that controls the engine 51. The controller 75 is connected to the engine 51 and outputs a stop command to the engine 51. The controller 75 has a function (idling stop function) for stopping the engine 51 when a predetermined condition is satisfied.

(Operation of engine control means)
A flowchart of the operation of the controller 75 is shown in FIG. 3 (refer to FIG. 1 and FIG. 2 for each component of the crane 1 described above). The outline of the operation of the controller 75 is as follows. That is, when the state where the sensor 71 detects that the actuator 60 is not moving continues for a predetermined time (steps S2 and S3) and the load detected by the load detection means 72 is smaller than the weight of the attachment 30 ( In step S4), the engine 51 is stopped (step S5). Hereinafter, the operation of the engine 51 will be described as an initial condition (see step S1).

  In step S2, it is determined whether the actuator 60 is not moving. More specifically, in step S2, it is determined whether or not the sensor 71 detects that none of the plurality of actuators 60 is moving (the details of the “actuator 60 is moving” state are described in the explanation of the sensor 71). See). Specifically, in step S2, the attachment 30 is not hoisted or lowered (not in a free fall state), and other crane operations (such as raising / lowering the boom 20, turning or running) are not performed. It is determined whether or not it is in a state. If the actuator 60 is not moving, the process proceeds to step S3. When the actuator 60 is moving, the rotation of the engine 51 is continued (step S6). Note that “continue rotation of the engine 51” means that the engine 51 is not stopped based on the idling stop function (for example, the engine 51 may be stopped by operating an engine key or the like).

  In step S3, it is determined whether or not a state satisfying the condition of step S2 (a state in which the sensor 71 detects that none of the plurality of actuators 60 is moving) continues for a predetermined time. If the predetermined time has not been continued, the rotation of the engine 51 is continued (step S6). If it continues for a predetermined time, the process proceeds to step S4.

In step S <b> 4, it is determined whether or not the load of the attachment 30 detected by the load detection unit 72 is smaller than the weight of the attachment 30. That is, in step S4, it is determined whether or not the head H of the attachment 30 is zero. If the load on the attachment 30 is greater than or equal to the weight of the attachment 30, the rotation of the engine 51 is continued (step S6). If the load is smaller than the own weight, the engine is stopped (step S5) and the process is terminated.
In step S4, it may be determined whether or not the load on the attachment 30 is smaller than a predetermined value. The predetermined value is a value smaller than the weight of the attachment 30 (a value determined based on the weight of the attachment 30). That is, in step S <b> 4, it may be determined whether or not the load of the attachment 30 is largely less than the weight of the attachment 30. When such determination is performed, it can be determined more reliably that the head H of the attachment 30 is zero.

(Characteristics of crane of this embodiment)
(Feature 1)
As shown in FIG. 1, the crane 1 includes an attachment 30 that is suspended from the boom 20 via a hoisting rope 25 that is wound around a winch drum 61 d (see FIG. 2) of the winch assembly 61. Further, the determination in step S2 (hereinafter, refer to FIG. 3 for steps S2 to S5) is performed. That is, the condition for stopping the engine 51 by the controller 75 (step S5) includes “the sensor 71 detects that none of the plurality of actuators 60 is moving” shown in FIG.
When the condition of step S2 is satisfied, the winch drum 61d (see FIG. 2) of the winch assembly 61 shown in FIG. Absent. That is, when the condition of step S2 is satisfied, the attachment 30 is not in a free fall state (state A).

The crane 1 also includes load detection means 72 (see FIG. 2) that detects the load of the attachment 30. Further, the determination in step S4 is performed. That is, the condition for stopping the engine 51 by the controller 75 includes that “the load detected by the load detecting means 72 is smaller than the weight of the attachment 30 (see FIG. 1)” shown in FIG.
When the condition of step S4 is satisfied, the head H of the attachment 30 shown in FIG. That is, the attachment 30 is deposited on a reference plane D (such as the ground). In other words, the attachment 30 is not supported only by being suspended from the boom 20 via the hoisting rope 25 but is supported by the reference plane D. In this state, the attachment 30 is not beaten (state B).

  In the crane 1, when the state A and the state B are satisfied, the controller 75 shown in FIG. 2 stops the engine 51 (step S5). Therefore, the engine 51 can be automatically stopped when the attachment 30 (see FIG. 1) is in a safe state.

In addition, this crane 1 is provided with the idling stop function similar to the prior art. More specifically, the crane 1 includes a plurality of actuators 60 that are driven using the engine 51 as a power source. In addition, determinations in steps S2 and S3 are performed. That is, the condition for stopping the engine 51 by the controller 75 includes “a state in which the sensor 71 detects that none of the plurality of actuators 60 is moving for a predetermined time”.
When the condition of step S2 is satisfied, since the plurality of actuators 60 are not moving, the operation of the engine 51 for driving the plurality of actuators 60 is not necessary. Furthermore, when this state continues for a predetermined time (step S3), there is a high possibility that the operator (operator) of the crane 1 does not intend to operate the actuator 60. The engine 51 may automatically stop when the conditions of these steps S2 and S3 are satisfied (step S5). Therefore, idling of the engine 51 can be stopped at an appropriate time. As a result, the fuel consumption of the crane 1 can be reduced (power reduction), and exhaust and noise can be reduced.

In addition, the crane 1 also has the above-described effect even when it is provided with an attachment 30 (see FIG. 1) for civil engineering work.
In the prior art described in Patent Document 1, the condition of automatic stop of the engine 51 (see FIG. 2) includes “a state where there is no suspended load”. In the above-described prior art, if the portion (for example, a vibro hammer) other than the hook of the attachment 30 for civil engineering work is considered as a “hanging load”, the engine 51 does not automatically stop because the above condition is not satisfied. Moreover, even if the said part is considered as a part of attachment 30, there exists a possibility that the danger that the attachment 30 may be beaten as mentioned above may arise.

(Feature 2)
The crane 1 includes attachment weight setting means 73 (see FIG. 2) for setting the weight of the attachment 30 (see FIG. 1). Therefore, even when the specification of the attachment 30 is changed, if the weight of the attachment 30 is set by the attachment weight setting means 73, the effect described in the feature 1 is surely produced.

(Modification)
In the above embodiment, the condition determination in steps S2 to S4 shown in FIG. 3 is performed. However, the order and contents of the condition determination may be changed within a range in which the effect of the present invention is achieved. For example, there are two conditions: a condition that the actuator 60 (see FIG. 1) is not moving (step S2) and a condition that the detected load is less than the weight of the attachment 30 (see FIG. 1) (step S4). It may be considered that the controller 75 shown in FIG. 2 stops the engine 51 when the state that is satisfied simultaneously continues for a predetermined time. This modified example and the above embodiment are substantially the same (because the condition of step S4 is not switched in a state where the condition of step S2 is satisfied).

  As shown in FIG. 1, in the said embodiment, although the boom 20 was raised and lowered using the gantry 40, the structure which raises and lowers the boom 20 can be variously deformed. Specifically, for example, the box-shaped boom 20 may be raised and lowered by a cylinder (not shown). In this case, for example, the load on the attachment 30 is detected by detecting the load applied to the cylinder. Further, for example, the boom 20 may be raised and lowered with a mast (not shown) provided between the gantry 40 and the boom 20. In this case, for example, the load on the attachment 30 is detected by detecting the tension of a guy line (not shown) connecting the mast and the boom 20.

DESCRIPTION OF SYMBOLS 1 Crane 10 Crane main body 51 Engine 60 Several actuators 20 Boom 61 Winch assen (some actuators among several actuators)
25 Hoisting rope 30 Attachment 71 Sensor (Actuator operation detection means)
72 Load detection means 75 Controller (engine control means)
73 Attachment weight setting means

Claims (2)

The crane body,
An engine provided in the crane body;
A plurality of actuators driven using the engine as a power source;
A boom attached to the crane body;
An attachment suspended from the boom via a hoisting rope wound around some of the plurality of actuators;
An actuator operation detecting means for detecting whether or not the plurality of actuators are moving;
Load detection means for detecting the load of the attachment;
Engine control means for controlling the engine,
The engine control means includes
When the state in which the actuator operation detecting means detects that none of the plurality of actuators is moving continues for a predetermined time and the load detected by the load detecting means is smaller than the weight of the attachment, the engine Stop the crane. The crane according to claim 1, further comprising attachment weight setting means for setting the weight of the attachment.

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