JP2017024825A - Mobile crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile crane enabling proper travel of a counter weight carriage in a plurality of carriage travel modes.SOLUTION: A mobile crane comprises: a crane body 3 including a lower traveling body 10 and an upper revolving body 12; a traveling drive device for running the lower traveling body 10; a revolving drive device for revolving the upper revolving body 12; a revolving brake device for applying a brake force to the revolution of the upper revolving body 12 while varying the brake force; a self-propelled counter weight carriage 14; a connection member 26 connecting the upper revolving body 12 and the counter weight carriage 14; a mode designation part for designating a specific carriage travel mode from a plurality of carriage travel modes; a carriage control part for controlling the movement of the counter weight carriage 14 according to the designated carriage travel mode; and a revolving brake control part for switching the brake force applied to the revolution of the upper revolving body 12 by the revolving brake device according to the designated carriage travel mode.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a mobile crane provided with a counterweight carriage.

  2. Description of the Related Art Conventionally, a mobile crane is known that includes a crane body that can travel and a counterweight carriage that can travel following the crane body. The counterweight carriage is connected to the crane main body via a connecting member, and is equipped with a counterweight. The weight of the counterweight increases the stability of the crane main body and improves its suspension capacity.

  As such a mobile crane, Patent Document 1 discloses a lower traveling body, an upper revolving body mounted on the lower traveling body so as to be able to swivel around a vertical turning center axis, and the upper revolving body. A counterweight carriage connected to the rear part via a connecting member is disclosed. The lower traveling body constitutes a crane body together with the upper revolving body, and self-travels according to the operation of the operating lever for traveling. The counterweight trolley includes a plurality of wheels and a trolley travel motor, and the trolley travel motor rotationally drives the wheels in response to an operation of the operation lever, whereby the counterweight trolley is It is possible to drive following the road.

  Each wheel of the counterweight carriage can turn around a vertical axis parallel to the turning center axis of the upper turning body, and the direction of the wheel is changed, that is, steered by the turning. This steering allows the counterweight carriage to travel in various postures. For example, in Patent Document 1, as a running mode of the counterweight carriage, the wheel of the counterweight carriage is directed in the turning direction of the upper turning body, and the counterweight carriage follows the turning of the upper turning body. Disclosed are turning traveling that travels in the turning direction and transverse traveling in which the wheels of the counterweight carriage are directed in the traveling direction of the lower traveling body and the counterweight carriage travels in synchronization with the traveling of the lower traveling body. Has been.

Japanese Patent Laid-Open No. 5-208796

  Patent Document 1 describes the synchronous control for causing the counterweight carriage to follow the movement of the lower traveling body and the upper swing body, but the braking of the upper swing body during the synchronous control is described. Is not mentioned at all. Even if the same synchronous control is performed, an excessive load may be applied to the connecting member or other members depending on the braking force applied to the turning of the upper turning body.

  An object of this invention is to provide the mobile crane which can solve the above subjects. The mobile crane provided is a crane main body including a self-propelled lower traveling body and an upper revolving body mounted on the lower traveling body so as to be capable of swiveling, and a traveling drive for causing the lower traveling body to travel. An apparatus, a turning drive device for turning the upper turning body, a turning braking device capable of applying a braking force to the turning of the upper turning body and changing the braking force, and a counterweight A counterweight carriage capable of self-propelling, a connecting member that connects the upper swing body and the counterweight carriage, and a plurality of carriage running modes that are set in advance for running of the counterweight carriage are specified. It follows the movement of the crane body in a mode specification section for specifying a truck travel mode and a truck travel mode in which the counterweight cart is designated. In this way, a cart controller that controls the movement of the counterweight cart according to the cart running mode, and the control that the turning braking device gives to the turning of the upper turning body according to the designated cart running mode. A turning braking control unit for switching power.

  Specifically, the counterweight carriage is connected to the upper swing body via the connecting member and supports the counterweight, a plurality of wheels attached to the carriage body, and the counterweight A wheel drive device that rotationally drives at least a part of the plurality of wheels so that the cart travels, and a steering device that changes the direction of the plurality of wheels, and the cart control unit includes a counterweight cart of the counterweight cart What controls the operation | movement of the said wheel drive device and the said steering device so that the some trolley | bogie driving mode preset about driving | running | working is each implement | achieved is suitable.

  According to the mobile crane, the braking force applied by the turning braking device to the turning of the upper turning body is variable, and the braking force is switched by the designated carriage traveling mode. The upper revolving unit can be restrained in accordance with the counter weight, thereby reducing the load applied to the connecting member for connecting the upper revolving unit and the counterweight carriage or the surrounding members while reducing the counterweight in each carriage traveling mode. The cart can run.

  Examples of the plurality of carriage running modes include a turning running mode in which the counterweight carriage runs in the turning direction following the turning of the upper turning body, and the lower running following the running of the lower traveling body. A translation mode in which the counterweight carriage travels so as to translate with the body is included. In this case, when the turning stop holding command is given in the turning traveling mode, the turning braking control unit gives a turning stop holding braking force to the turning of the upper turning body, and at least in the translation running mode, When the counterweight carriage translates with the lower traveling body in a state of being positioned on the side of the lower traveling body, a translational traveling braking force weaker than the turning stop holding braking force is applied to the turning of the upper revolving body. Thus, it is preferable to switch the braking force.

  Here, “translate with the lower traveling body in a state where the counterweight carriage is located on the side of the lower traveling body” means that the counterweight carriage is in the width direction of the lower traveling body (perpendicular to the traveling direction of the lower traveling body). (Translation direction) is a translation in a state located outside the both ends of the direction. Hereinafter, the translation in this state is referred to as a lateral translation. The braking force in translation other than the side translation is not particularly limited.

  According to this braking control, when the turning stop holding command is given, the upper turning body can be reliably held in the turning stopped state by the turning stop holding braking force, while at least the counterweight carriage is When translating sideways with respect to the lower traveling body, the upper revolving body is restrained by the translational traveling braking force that is weaker than the turning stop holding braking force, so that the traveling speed of the lower traveling body and the traveling speed of the counterweight carriage are reduced. It is possible to prevent an excessive load from being applied to the connecting member or the like due to a slight deviation between the two. For example, if a braking force is not applied to the turning of the upper swing body during the lateral translation, the counterweight cart connected to the upper swing body while turning the upper swing body due to the shift of the traveling speed may be a crane. Although the relative displacement with respect to the main body is attempted, since the length of the connecting member is fixed, the larger the relative displacement is, the more the load acting on the connecting member or its surrounding members (particularly the connecting member is bent). There is a risk that the load in such a direction will increase significantly. On the other hand, when a large braking force such as the turning stop holding braking force is applied to the turning of the upper turning body, the entire crane including the crane body and the counterweight carriage becomes rigid. A large load acts on the surrounding members. On the other hand, by providing a translational braking force that is weaker than the turning stop holding braking force during the lateral translation, a deviation in the traveling speed of the counterweight carriage with respect to the traveling speed of the lower traveling body is reduced. It can be absorbed by a moderate turn (a turn that is not a free turn but a restriction with a moderate braking force applied), and a large load acts on the connecting member and other parts. Can be deterred.

  The turning braking device may include a plurality of types of turning brakes that each exert different braking force, or may include only a single turning brake with variable braking force, and the braking force may be in a cart travel mode. It may be adjusted by. For example, a turning parking brake that is selectively switched between a state in which a first braking force is applied to the turning of the upper turning body and a state in which the first braking force is released is different from the turning parking brake. A brake positive brake that applies a braking force corresponding to the input braking force command to the turning of the upper swing body, and a control corresponding to the operation in response to an operation for inputting the braking force command. A braking operation unit that inputs a power command to the turning positive brake, and a first braking force applied to the upper turning body regardless of an operation that a braking force command applied to the turning positive brake is applied to the braking operation unit. And a forced braking switching unit that forcibly switches to a braking force command that gives a weaker second braking force. Using the key, with only a simple structure of adding the forced braking switching unit thereto, it is possible to switch the braking force between said second braking force to the first braking force.

  In the case where such a turning braking device is provided, and the plurality of bogie driving modes include the turning driving mode and the translation driving mode, the turning braking control unit controls the turning stop holding command in the turning driving mode. Is applied to at least the turning parking brake, and in the translation mode, at least the counterweight carriage is in translation with the lower traveling body in a state of being located on the side of the lower traveling body. When the turning brake is applied, the application of the first braking force by the turning parking brake is canceled and the forced braking switching unit is operated to turn the upper turning body against the turning of the upper turning body regardless of the operation given to the braking operation unit. By applying the second braking force to the brake, the turning traveling mode and the translation traveling mode are applied. It can be applied braking force which is suitable for de (the first and second braking force) to the turning of the upper rotating body.

  As described above, according to the present invention, by switching the braking force applied to the upper-part turning body according to the bogie running mode of the counterweight bogie, it is possible to run an appropriate counterweight bogie in each bogie running mode. effective.

It is a side view of the mobile crane which concerns on embodiment of this invention. FIG. 5 is a plan view schematically showing a state in which the turning angle of the upper turning body with respect to the lower running body is 0 ° and the counterweight carriage is in the translation running mode in the mobile crane. It is the top view which showed typically the state in which the turning angle of the said upper turning body with respect to the said lower running body is 45 degrees, and a counterweight trolley | bogie is in translation running mode. It is the top view which showed typically the state in which the turning angle of the said upper turning body with respect to the said lower running body is 90 degrees, and a counterweight trolley | bogie is in translation driving mode. It is the top view which showed typically the state in which the said counterweight trolley | bogie is in turning driving mode. It is a block diagram which shows the drive control system of the said mobile crane. It is a hydraulic circuit diagram which shows the turning drive device and turning brake device of the said mobile crane. It is a block diagram which shows the function regarding switching control of a bogie driving mode, and turning braking control among the functions which the main body side control part of the said mobile crane has. It is a flowchart which shows the content of the said turning braking control.

  Preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a mobile crane according to an embodiment of the present invention. This mobile crane includes a crane body 3 and a counterweight carriage 14. The crane body 3 includes a lower traveling body 10 and an upper swing body 12. The counterweight carriage 14 increases the stability of the crane body 3 and improves its suspension capacity, and travels following the movement of the crane main body 3 while being connected to the crane body 3. Is possible.

  The lower traveling body 10 includes a traveling frame 13 and a pair of crawlers 11 positioned on both outer sides of the traveling frame 13 in the left-right direction, that is, in the vehicle width direction. 2 to 5 travels on the traveling surface G along the front-rear direction of the lower traveling body 10 as indicated by the arrow A1. The front-rear direction is a direction that coincides with the longitudinal direction of each of the crawlers 11, and is a direction that is orthogonal to the vehicle width direction.

  The upper revolving structure 12 has a revolving frame 15, a boom 16 and a mast 18 as shown in FIG.

  The turning frame 15 is mounted on the lower traveling body 10 so as to be turnable. The turning frame 15 according to this embodiment can turn about a turning center axis C1 in a vertical direction orthogonal to the traveling direction of the lower traveling body 10 (for example, orthogonal to the traveling surface G). Thus, it is attached to the traveling frame 13. As shown by an arrow A <b> 2 in FIGS. 2 to 5, the revolving frame 15 is set with a front / rear direction independent of the front / rear direction of the lower traveling body 10 (the front / rear direction of the upper revolving body 12).

  The boom 16 can perform the hoisting operation by turning around the hoisting and turning shaft parallel to the left and right direction (direction orthogonal to the front and rear direction) of the upper turning body 12. Installed at the front end. In other words, the boom 16 has a base end portion that is connected to the front end portion of the revolving frame 15 so as to be rotatable around the undulation rotation shaft, and a distal end portion that is the opposite end portion. A suspension tool 20 is suspended from the tip portion via a rope 19, and a suspended load is engaged with the suspension tool 20.

  The mast 18 is a member for raising and lowering the boom 16. The mast 18 is raised and lowered by a not-illustrated mast raising and lowering device mounted on the upper swing body 12, and the boom 16 is raised and lowered in conjunction therewith. Specifically, the mast 18 has a base end portion that is rotatably connected to an intermediate portion in the front-rear direction of the revolving frame 15, and a distal end portion on the opposite side, and the distal end portion is a boom guy line 22. It is connected to the tip part of the boom 16 via. Therefore, the mast 18 can support the boom 16 in the standing state from behind via the boom guy line 22.

  The counterweight carriage 14 includes a carriage body 27, a counterweight 28 mounted on the carriage body 27, and a pair of wheel units 30 </ b> A and 30 </ b> B disposed on the lower side of the carriage body 27. The upper revolving unit 12 is disposed behind the revolving frame 15.

  The bogie main body 27 is connected to the tip of the mast 18 via an up-down bogie guide line 24 as shown in FIG. 1, and the upper revolving body 12 is connected via a connecting beam 26 that is a connecting member. It is connected to the rear portion of the swing frame 15, thereby improving the stability of the crane 2 by balancing the suspension load applied to the front portion of the upper swing body 12 and the load of the boom 16 during the suspension work, thereby improving the crane 2. Improve the suspension capacity of

  The connection beam 26 has a structure that can be expanded and contracted in the longitudinal direction, for example, a telescopic structure, and the distance between the turning frame 15 and the counterweight carriage 14 can be changed by the expansion and contraction. The length of the connecting beam 26 is fixed when the counterweight carriage 14 is traveling. For example, when the connecting beam 26 has the telescopic structure, that is, a structure composed of a plurality of box members that can slide in the longitudinal direction of the connecting beam 26 while being fitted to each other, Is carried out by fastening with bolts or the like.

  Each of the wheel units 30 </ b> A and 30 </ b> B includes a plurality of wheels 32 that face in the same direction and a wheel support frame (not shown) that supports these wheels 32. Each wheel 32 can rotate such that the counterweight carriage 14 is self-propelled independently of the lower traveling body 10. Specifically, each wheel 32 is rotated around a rotation center axis parallel to the reference surface (for example, parallel to the traveling surface G) so that the wheel 32 can roll on a reference surface orthogonal to the turning center axis C1. It is supported by the wheel support frame so as to rotate.

  Further, each of the wheel units 30A and 30B can be operated so as to collectively change the direction of the wheels 32, and can have a plurality of bogie travel modes by changing the direction. . Specifically, the wheel units 30A and 30B are attached to the carriage main body 27 so as to be able to turn around a vertical steering axis C2 parallel to the turning central axis C1, and the steering axis C2 By turning around, the directions of the wheels 32 are collectively changed.

  In this embodiment, the plurality of bogie travel modes include A) a translation travel mode as shown in FIGS. 2 to 4, B) a turning travel mode as shown in FIG. 5, and C) a single travel mode, including.

  A) In the translational travel mode, the upper revolving unit 12 is rotated at an arbitrary angle, and the wheels 32 are rotationally driven in a state where the direction of each wheel 32 matches the front-rear direction of the lower revolving unit 10. This is a mode in which the counterweight carriage 14 travels following the traveling of the lower traveling body 10. That is, in this translation travel mode, the counterweight carriage 14 is driven so as to travel in the same direction as the lower traveling body 10, that is, translate.

  B) In the turning mode, the wheel 32 is rotationally driven in a state where the direction of each wheel 32 matches the turning direction of the upper turning body 12, so that the counter follows the turning of the upper turning body 12. In this mode, the weight carriage 14 travels. That is, in this turning traveling mode, the counterweight carriage 14 is driven so as to travel along an arcuate track centering on the turning center axis C <b> 1 of the upper turning body 12.

  C) The single travel mode is a mode in which only the counterweight carriage 14 travels alone with the crane main body 3 stopped, and the telescopic boom 26 is expanded and contracted (that is, between the turning frame 15 and the counterweight carriage 14). Used to change the distance). In addition to this single traveling mode, a mode in which only the traveling of the lower traveling body 10 is performed while the counterweight carriage 14 is stopped in the D) carriage stopping mode may be set. This mode can also be used to extend and retract the telescopic boom 26.

  Next, a drive control system mounted on the mobile crane will be described with reference to FIG.

  The crane body 3 includes a crawler driving device 33, a traveling operation device 34, a turning operation device 36, a turning driving device 38, a turning angle detector 39, a turning braking device 40, a turning stop holding switch 41, as shown in FIG. A mode selection device 42 and a main body side control unit 44 are mounted.

  The crawler drive device 33 is a travel drive device that travels the lower traveling body 10, and drives the lower traveling body 10 by driving the pair of crawlers 11.

  The traveling operation device 34 is used for instructing traveling (forward or backward) and traveling stop of the crane body 3, and is provided in an unillustrated cab included in the upper swing body 12. The travel operation device 34 includes a travel operation lever 34a and an operation device main body 34b. The traveling operation lever 34a is given a rotation operation for designating the traveling direction and traveling speed of the lower traveling body 10. The operation device main body 34 b generates a command signal regarding the travel direction corresponding to the direction of operation given to the travel operation lever 34 a and the travel speed corresponding to the amount of the operation, and inputs the command signal to the main body side control unit 44.

  The turning operation device 36 is used for instructing turning driving and turning stop of the upper turning body 12 and is provided in the driver's cab. The turning operation device 36 includes a turning operation lever 36a and an operation device main body 36b. A turning operation for designating the turning direction and turning speed of the upper turning body 12 is given to the turning operation lever 36a. The operating device main body 36 b generates a command signal regarding the turning direction corresponding to the direction of the operation given to the turning operation lever 36 a and the turning speed corresponding to the amount of the operation, and inputs the command signal to the main body side control unit 44.

  The turning drive device 38 is a device for turning the upper turning body 12 (the turning frame 15 thereof) around the turning center axis C1, and includes a turning motor 58, a speed reducer 60, a hydraulic pump 62, and turning control as shown in FIG. A circuit 64 is included.

  The turning motor 58 is a hydraulic motor having a pair of ports and an output shaft, and the output shaft is connected to the turning frame 15 via the speed reducer 60. When the hydraulic oil is supplied from the hydraulic pump 62 to any port of the swing motor 58 through the swing control circuit 64, the output shaft rotates in a direction corresponding to the supplied port. The swivel frame 15 is swung in the direction. At the same time, the turning motor 58 discharges hydraulic oil from the other port, and this hydraulic oil is returned to the tank T through the turning control circuit 64.

  The turning control circuit 64 is interposed between the turning motor 58 and the hydraulic pump 62, receives an instruction signal from the main body side control unit 44, and operates from the hydraulic pump 62 to the turning motor 58. Change the oil supply direction and flow rate. The turning control circuit 64 includes, for example, a control valve including a pilot switching valve for switching an oil path between the hydraulic pump 62 and the turning motor 58, a pilot line for supplying pilot pressure to the control valve, Including an electromagnetic proportional pressure reducing valve provided in the pilot line, and a speed command signal from the main body side control unit 44 is input to the electromagnetic proportional pressure reducing valve, thereby controlling the supply direction and supply flow rate of the hydraulic oil, that is, the The turning direction and the turning flow rate of the turning frame 15 are controlled.

  The turning angle detector 39 generates a detection signal corresponding to the turning angle of the turning frame 15 and inputs the detection signal to the main body side control unit 44. This detection signal is used for controlling the turning drive by the turning drive device 38.

  The turning braking device 40 is a device for braking the turning of the upper turning body 12, and in this embodiment, a turning parking brake 66, a turning positive brake 68, and a parking brake hydraulic source as shown in FIG. 70, a parking brake switching valve 72, a positive brake hydraulic power source 74, a brake pedal 75, and a positive brake mode switching circuit 76.

  The turning parking brake 66 is a so-called negative brake, and when the hydraulic oil is not supplied from the parking brake hydraulic power source 70, the turning motor 58 (for example, the turning output shaft) turns the upper turning body 12 to turn. A first braking force Fb1 (for example, 120 kgf · m) that is a braking force for holding the turning stop of a predetermined magnitude for holding the stop is applied (brake ON), and the braking force is applied when the hydraulic oil is supplied. Is released (brake OFF). The parking brake switching valve 72 is, for example, an electromagnetic switching valve, and is interposed between the turning parking brake 66 and the parking brake hydraulic pressure source 70. The parking brake switching valve 72 opens and closes in response to a switching command signal input from the main body side control unit 44. That is, the state is switched between a state where the supply of the hydraulic oil from the parking brake hydraulic power source 70 to the turning parking brake 66 is permitted and a state where the hydraulic fluid is blocked.

  The swing positive brake 68 receives a supply of hydraulic oil from the positive brake hydraulic power source 74, that is, receives a brake pressure as a braking force command, and engages with an output shaft of the swing motor 58. A braking force with a magnitude corresponding to the brake pressure and against the turning of the upper turning body 12 is applied to the disk 73.

  The brake pedal 75 is provided in the driver's cab and receives an operation (for example, a stepping operation) for commanding a braking force by the turning positive brake 68.

  The positive brake mode switching circuit 76 has a mode for giving a braking force command (brake pressure) to the turning positive brake 68, a normal operation mode for giving a braking force command corresponding to an operation given to the brake pedal 75, and Regardless of the amount of operation of the brake pedal 75, the mode is switched to a forced command mode in which the braking force command (brake pressure) given to the brake pedal 75 is forcibly switched to a preset braking force command. Specifically, the positive brake mode switching circuit 76 has both a first brake pressure supply line 78A used in the normal operation mode and a second brake pressure supply line 78B used in the forced command mode. Both supply lines 78A and 78B are arranged in parallel with each other between the positive brake hydraulic power source 74 and the turning positive brake 68.

  The first brake pressure supply line 78A is provided with a brake valve 80 and a first on-off valve 82A in order from the upstream side.

  The brake valve 80 is a manually operated pressure reducing valve, mechanically connected to the brake pedal 75, and a secondary pressure (brake pressure) of the brake valve 80 corresponding to an operation amount of the brake pedal 75. Adjust to. Therefore, the brake valve 80 and the brake pedal 75 constitute a braking operation unit that causes the braking positive brake 68 to input a braking force command corresponding to an operation given to the brake pedal.

  The first on-off valve 82A is a two-position pilot switching valve, and has an open position for opening the first brake pressure supply line 78A and a closed position for blocking. The first on-off valve 82A maintains the open position when a pilot pressure above a certain level is not supplied to the first on-off valve 82A, and is switched to the closed position when the pilot pressure above a certain level is supplied.

  The second brake pressure supply line 78B is provided with a throttle 84, a line switching valve 86, and a second on-off valve 82B in this order from the upstream side, and a line switching pilot circuit 88 on the secondary side of the line switching valve 86. Is connected.

  The throttle 84 restricts the flow rate in the second brake pressure supply line 78B, so that the brake pressure supplied to the turning positive brake 68 through the second brake pressure supply line 78B is supplied to the positive brake hydraulic power source 74. The brake pressure is adjusted to a predetermined brake pressure lower than the discharge pressure. The brake pressure is a translation travel brake pressure used in the translation travel mode, and the translation travel brake pressure is a braking force applied to the swing motor 58 by the swing positive brake 68. 66 is a brake pressure for making a translational braking force which is a second braking force Fb2 (<Fb1) lower than the first braking force Fb1 applied to the turning motor 58 by 66. The second braking force Fb2 is a braking force (for example, 90 kgf · m) that is suitable for restraining the turning of the upper turning body 12 to an appropriate degree during translation, which will be described later, particularly during lateral translation. Specific values of the second braking force Fb2 and the first braking force Fb1 are appropriately set according to the specifications of the crane.

  In the example shown in FIG. 7, the line switching valve 86 includes a two-position electromagnetic switching valve 86, and the first selection position (the left-side position in FIG. 7) according to the switching command signal input from the main body side control unit 44. ) And the second selection position (right position in FIG. 7). In the first selected position, the line switching valve 86 shuts off the second brake pressure supply line 78B and uses the secondary side line of the line switching valve 86 in the second brake pressure supply line 78B as a tank. In communication, the second brake pressure supply line 78B is opened at the second selected position.

  The second on-off valve 82B is a two-position pilot switching valve, and has an open position for opening the second brake pressure supply line 78B and a closed position for blocking. The second on-off valve 82B maintains the closed position when a pilot pressure exceeding a certain level is not supplied to the second on-off valve 82B, and is switched to the open position when the pilot pressure above a certain level is supplied.

  The line switching pilot circuit 88 is linked to the position switching of the line switching valve 86 by guiding the secondary pressure of the line switching valve 86 as a pilot pressure to the first and second on-off valves 82A and 82B. Then, the first and second on-off valves 82A and 82B are opened and closed. That is, when the line switching valve 86 is in the first selection position, the line switching pilot circuit 88 supplies the pilot pressure supplied to the first and second on-off valves 82A and 82B to the second of the line switching valve 86. By reducing the pressure to the pressure corresponding to the secondary pressure, that is, the tank pressure, the first on-off valve 82A is kept in the open position and the second on-off valve 82B is kept in the closed position, thereby supplying the first brake pressure. While the line 78A is put into use, when the line switching valve 86 is in the second selected position, the pilot pressure supplied to the first and second on-off valves 82A and 82B is set to the line switching valve 86. By raising the pressure on the secondary side, that is, the pressure corresponding to the brake pressure for translation travel, the first on-off valve 82A is switched to the closed position and the second A state where the switching valve closing 82B in the open position the second brake pressure supply line 78B is used.

  Therefore, in the turning braking device 40 according to this embodiment, the throttle 84, the line switching valve 86, the first and second on-off valves 82A and 82B, and the line switching pilot circuit 88 are connected to the brake pedal 75. A forced braking switching unit is configured to forcibly switch the brake pressure, which is a braking force command applied to the turning positive brake 68, to the brake pressure for translation regardless of the operation.

  The turning stop holding switch 41 is provided in the driver's cab and inputs a turning stop holding command to the main body side control unit 44 when receiving an ON operation.

  The mode selection device 42 allows the operator to select from a plurality of bogie driving modes set as described above for the running of the counterweight bogie 14, that is, the turning mode, the translation mode, the single mode, and the driven mode. This mode designation unit is used for selecting a desired bogie travel mode, that is, designating a bogie travel mode to be executed. Specifically, the mode selection device 42 includes a selection unit 46 and a transmission unit 48. The selection unit 46 includes, for example, a plurality of selection buttons, and receives an operation performed by an operator to select the cart traveling mode. The transmission unit 48 inputs a mode selection signal for designating the bogie travel mode selected by the operation of the selection unit 46 to the main body side control unit 44.

  The main body side control unit 44 controls the crane main body 3 based on signals input from the traveling operation device 34, the turning operation device 36, the turning angle detector 39, the turning stop holding switch 41, and the mode selection device 42, respectively. Various controls are performed. Specifically, the following control is performed.

1) Body-side travel drive control The body-side controller 44 generates a travel control signal based on a command signal (travel command signal) input from the travel operation device 34 and inputs the travel control signal to the crawler drive device 33. The crawler device 11 is operated so that the lower traveling body 10 travels at a traveling speed corresponding to the operation in the traveling direction corresponding to the operation given to the traveling operation lever 34a of the traveling operation device 34.

2) Turning Drive Control The main body side control unit 44 generates a turning control signal based on a command signal (turning command signal) input from the turning operation device 36 and sends it to the turning drive device 38 (for example, the turning control circuit 64). Thus, the turning drive device 38 turns the upper turning body 12 in the turning direction corresponding to the operation given to the turning operation lever 36a of the turning operation device 36 at the turning speed corresponding to the operation. Is activated.

3) Mode switching control and turning braking control The main body side control unit 44 inputs a mode command signal to the cart side control unit 56 so as to realize the cart running mode selected by the operator using the mode selection device 42. Further, a braking control signal is input to the turning braking device 40 so that the turning braking device 40 switches the braking force applied to the turning of the upper turning body 12 in accordance with the selected cart traveling mode. These mode switching control and turning braking control will be described in detail later.

  On the other hand, the counterweight carriage 14 has a first steering angle detector 50A, a second steering angle detector 50B, a first steering device 52A, and a second steering as shown in FIG. 6 as the drive control system. The apparatus further includes a device 52B, a first travel drive device 54A, a second travel drive device 54B, and a cart side controller 56.

  The first and second steering angle detectors 50A and 50B detect the steering angle of the first and second wheel units 30A and 30B, that is, the rotation angle around the steering center axis C2, respectively. . Specifically, the first and second steering angle detectors 50 </ b> A and 50 </ b> B generate detection signals related to the steering angles of the corresponding wheel units 30 </ b> A and 30 </ b> B and input them to the carriage side control unit 56.

  The first and second steering devices 52A and 52B are attached to the pair of wheel units 30A and 30B, respectively, and the corresponding wheel unit 30A or 30B is moved around the steering center axis C2 with respect to the carriage main body 27. The plurality of wheels 32 included in the wheel unit are steered integrally. Each steering device 52A, 52B receives a steering motor for turning the wheel units 30A, 30B and a command signal input from the cart side controller 56, and controls the operation of the steering motor. Direction control circuit. The counterweight carriage 14 is provided with a plurality of jack devices, and the jack apparatus jacks up the counterweight carriage 14, that is, each wheel 32 is lifted from the running surface G, and the first and first It is preferable that the steering by the two steering devices 52A and 52B is performed.

  The first and second wheel drive devices 54A and 54B are attached to the first and second wheel units 30A and 30B, respectively, and at least a part of the wheels 32 belonging to the corresponding wheel unit is used as a cart side control unit 56. Is rotated at a speed corresponding to the command signal in a direction corresponding to the command signal input from.

  The cart side control unit 56 realizes the cart traveling mode based on the mode command signal input from the main body side control unit 44, that is, based on the cart traveling mode selected using the mode selection device 42. The operation of the steering devices 52A and 52B and the wheel driving devices 54A and 54B is controlled.

  Specifically, when the A) translational travel mode is selected, the cart side controller 56 causes the first and second operations to match the direction of each wheel 32 with the longitudinal direction of the lower traveling body 10. Direction devices 52A and 52B are operated, and the first and second wheel drive devices 54A and 54B are operated so that the counterweight carriage 14 travels at a speed equal to the traveling speed of the lower traveling body 10.

  When the above-mentioned B) turning mode is selected, the cart-side control unit 56 causes the first and second steering devices 52A, 52A, 52 to match the direction of each wheel 32 with the turning direction of the upper turning body 12. 52B is operated, and the first and second wheel drive devices 54A and 54B are operated so that the counterweight carriage 14 is turned at a turning angular velocity equal to the turning angular velocity of the upper turning body 12.

  When the C) independent traveling mode, that is, the mode for extending / contracting the connecting beam 26 is selected, the cart side control unit 56 makes the direction of each wheel 32 parallel to the extending / contracting direction of the connecting beam 26. The first and second steering devices 52A and 52B are operated so as to match the direction (that is, the turning radius direction), and the counter is operated at a speed corresponding to the operation in a direction corresponding to the operation given to the traveling operation device 34. The first and second wheel drive devices 54A and 54B are operated so that the weight carriage 14 travels straight. Further, when the D) cart stop mode is selected, the rotation of each wheel 32 is prevented.

  Next, the 3) mode switching control and turning braking control performed by the main body side control unit 44 will be described with reference to FIGS.

  The main body side control unit 44 includes a carriage command unit 90 and a turning braking control unit 92 shown in FIG. 8 as functions for performing the mode switching control and the turning braking control.

  The cart command unit 90 determines the selected cart travel mode based on the mode selection signal input from the mode selection device 42, generates a mode command signal for the cart travel mode, and controls the cart side control. Input to the unit 56. Therefore, the cart command unit 90 and the cart side control unit 56 control the movement of the counterweight cart 14 so that the counterweight cart 14 follows the movement of the crane body 3 in the designated cart traveling mode. A cart control unit is configured.

  The turning braking control unit 92 causes the turning braking device 40 to turn the upper turning body 12 according to the carriage traveling mode determined by the carriage command unit 90 and the turning stop holding command input from the turning stop holding switch 41. A braking command signal is input to the turning braking device 40 so as to switch the braking force applied thereto. Specifically, the turning braking control unit 92 sends a switching command signal to the parking brake switching valve 72 and the line switching valve 86 of the turning braking device 40 shown in FIG. 6 according to the selected cart traveling mode. input.

  The control operation performed by the turning braking control unit 92 is shown in FIG. The control operation shown in the flowchart of FIG. 9 is a control operation when the counterweight carriage 14 is connected to the crane body 3, and when the counterweight carriage 14 is not connected, it is the same as that of a normal crane. A braking control operation is executed.

  In FIG. 9, when the turning traveling mode is selected as the bogie traveling mode (YES in step S1), the turning braking control unit 92 switches the braking state according to the operation content of the turning stop holding switch 41 (step S2). I do.

  Specifically, when the turning stop holding switch 41 is turned on, that is, when a turning stop holding command is input (YES in step S2), the turning braking control unit 92 opens the parking brake switching valve 72. The turning parking brake 66 is applied with the first braking force Fb1 with respect to the upper turning body 12 and the line switching valve 86 is set to the second selected position, so that the turning positive brake can be applied regardless of the operation of the brake pedal 75. The brake pressure for translation travel is applied to 68, and the turning positive brake 68 applies the second braking force Fb2 to the upper turning body 12 (forced braking state) (step S3). Thereby, the upper turning body 12 is held in a turning stopped state with a sufficient braking force. In addition, when the turning stop state of the upper swing body 12 can be sufficiently maintained only by the first braking force Fb1, the swing positive brake 68 is in the normal state (the braking force corresponding to the operation of the brake pedal 75 is applied to the upper swing body 12). May be maintained).

  When the turning mode is selected and the turning stop holding command is released, that is, when the turning stop holding switch 41 is not turned on (NO in step S2), the turning braking control unit 92 is The parking brake switching valve 72 is closed to release the braking by the turning parking brake 66 and the line switching valve 86 is set to the first selected position, so that the normal braking state, that is, the turning positive brake 68 is set to the brake pedal. The brake pressure corresponding to the operation 75 is applied, and the turning positive brake 68 is in a state of applying the braking force corresponding to the brake pressure to the upper turning body 12 (step S4). Thereby, the turning drive of the upper turning body 12 is allowed, and braking by the operator's operation of the brake pedal 75 is effective.

  On the other hand, when the translation travel mode is selected as the cart travel mode (NO in step S1 and YES in step S5), the turning braking control unit 92 switches the parking brake regardless of the operation of the turning stop holding switch 41. The valve 72 is closed and the braking by the turning parking brake 66 is released, and the line switching valve 86 is switched to the second selection position, so that the brake pressure for translation travel is applied to the turning positive brake 68 regardless of the operation of the brake pedal 75. A state in which the turning positive brake 68 applies a second braking force Fb2 weaker than the first braking force Fb1 by the turning parking brake 66 to the turning of the upper turning body 12 (forced braking state) ( Step S6). The application of the second braking force Fb2 makes it possible to perform a favorable translation while preventing an excessive load from being applied to the connecting beam 26 or other part as a connecting member.

  As an example, in a state where the counterweight carriage 14 is located on the side of the lower traveling body 10 as shown in FIG. 4 (in FIG. 4, the turning angle of the upper revolving body 12 with respect to the lower traveling body 10 is 90 °). Let us assume translational travel, that is, lateral translation in which the lower traveling body 10 and the counterweight carriage 14 travel in the same direction (the longitudinal direction of the lower traveling body 10). In this case, there is no problem when the traveling speed of the lower traveling body 10 and the traveling speed of the counterweight carriage 14 are always completely coincident with each other. The counterweight carriage 14 tends to be relatively displaced with respect to the lower traveling body 10 by this amount, and this may cause a large load to be applied to the connecting beam 26 or other members depending on the turning braking state of the upper turning body 12. is there.

  For example, when no braking force is applied to the turning of the upper turning body 12 during the lateral translation, the upper turning body 12 is connected to the upper turning body 12 while turning due to the shift in the traveling speed. The counterweight carriage 14 tends to be displaced relative to the lower traveling body 10. However, since the length of the connecting beam 26 during driving is fixed, the larger the relative displacement is, the more the load acting on the connecting beam 26 or its surrounding members (particularly, the connecting beam 26 is bent). There is a risk that the load in the direction will increase significantly.

  On the other hand, when a large braking force such as the first braking force Fb1 by the turning parking brake 66 is applied to the turning of the upper turning body 12, the entire crane including the crane body 3 and the counterweight carriage 14 is rigid. Therefore, the shift in the traveling speed also causes a large load to act on the connecting beam 26 or its surrounding members. This phenomenon becomes more remarkable as the turning angle of the upper turning body 12 is 90 ° or an angle close thereto as shown in FIG.

  On the other hand, when the second braking force Fb2 having an appropriate strength weaker than the first braking force Fb1 is applied to the turning of the upper turning body 12 during the lateral translation, a counter for the running speed of the lower running body 10 is provided. The shift of the running speed of the weight carriage 14 is not limited to an appropriate turning of the upper revolving body 12, that is, a free turning in a state where no braking force is applied, but is limited in a state where an appropriate braking force is applied. This can be absorbed by the swirling, and it is possible to prevent a large load from acting on the connecting beam 26 and other parts.

  In this embodiment, when the selected cart travel mode is neither the turning travel mode nor the translation travel mode (NO in steps S1 and S5), that is, the single travel mode or the cart stop mode is selected. When the connecting beam 26 is expanded and contracted, the turning braking control unit 92 releases the braking by the turning parking brake 66 and sets the turning positive brake 68 in the normal braking state, that is, the braking force corresponding to the brake pedal 75 is increased. The state is given to the swivel body 12 (step S4). The setting of the braking force in these modes can be changed as appropriate. In addition, the stand-alone travel mode and the cart stop mode may not necessarily be included in the cart travel mode.

  As described above, according to the mobile crane disclosed in FIGS. 1 to 9, the connecting beam 26 and other members are provided by applying the braking force according to the carriage traveling mode to the turning of the upper turning body 12. It is possible to satisfactorily execute each carriage traveling mode while preventing an excessive load from acting on the vehicle.

  However, the mobile crane according to the present invention is not limited to that disclosed in FIGS. The present invention can take the following forms, for example.

a) Turning Braking Device The turning braking device is not limited to the combination of the turning parking brake 66 and the turning positive brake 68 as described above. The turning braking device can change the braking force applied to the turning of the upper turning body by the turning braking device, in other words, the turning braking device can exhibit at least two kinds of braking forces having different sizes. I just need it. For example, a plurality of negative brakes each exhibiting different braking force may be combined, or conversely, a single positive brake whose braking force can be continuously changed is provided. It may be a thing. For example, by providing an electromagnetic proportional pressure reducing valve in place of the throttle 84 in the hydraulic circuit shown in FIG. 7, it is possible to freely change the braking force while using a single turning positive brake 68. However, the turning braking device 40 shown in FIG. 7 has an advantage that the braking force can be switched using the existing turning parking brake 66 and the turning positive brake 68 for manual operation.

b) Regarding the application of the braking force for translational travel The application of the braking force for translational travel is at least during lateral translation in which a particularly large bending load is likely to occur even in the translational travel mode, that is, in the width direction of the lower traveling body. What is necessary is just to carry out at the time of the translation driving | running | working in the state in which the counterweight trolley | bogie is located in the outer side of the said width direction rather than both ends. In other translational traveling, for example, when traveling with the counterweight carriage positioned immediately behind the lower traveling body, the bending load acting on the connecting member due to the shift in traveling speed is very small, Since the load generated as a whole is relatively small as compared with the side translation, a large braking force, for example, a braking force by the turning parking brake 66 may be applied to the upper turning body. Alternatively, the braking force may be completely released.

c) Turning Stop Holding Command The turning stop holding command is not limited to being input by a dedicated input unit such as the turning stop holding switch 41. For example, when the turning operation lever 36a of the turning operation device 36 is held at the neutral position for a predetermined time or more is regarded as a turning stop holding command, the turning operation lever 36a is operated from the neutral position by a certain amount or more. This may be regarded as cancellation of the turning stop holding command.

3 Crane body 10 Lower traveling body 12 Upper turning body 14 Counterweight carriage 26 Connection beam (connection member)
27 Carriage body 28 Counterweight 30A, 30B Wheel unit 32 Wheel 33 Crawler drive device (travel drive device)
DESCRIPTION OF SYMBOLS 38 Turning drive device 40 Turning brake device 41 Turning stop holding switch 42 Mode selection device 44 Main body side control part 52A, 52B Steering device 54A, 54B Wheel drive device 56 Carriage side control part (comprising a cart control part)
66 Turning parking brake 68 Turning positive brake 75 Brake pedal
80 Brake valve (comprising a braking operation unit)
82A, 82B On-off valve (composed of forced braking switching unit)
86 Line selector valve (composed of forced braking selector)
88 Pilot circuit for line switching (composed of forced braking switching part)
90 Cart command section
92 Turning braking control unit

Claims (5)

A mobile crane,
A crane body including a self-propelled lower traveling body and an upper revolving body mounted on the lower traveling body so as to be able to swivel;
A traveling drive device for traveling the lower traveling body;
A turning drive device for turning the upper turning body;
A turning braking device capable of applying a braking force to the turning of the upper turning body and changing the braking force;
A counterweight cart that can be self-propelled while being equipped with a counterweight;
A connecting member that connects the upper swing body and the counterweight carriage;
A mode designating unit for designating a specific cart running mode from a plurality of cart running modes set in advance for running of the counterweight cart;
A carriage control unit that controls movement of the counterweight carriage according to the carriage running mode so that the counterweight carriage runs following the movement of the crane body in the designated carriage running mode;
A swing crane comprising: a swing braking control unit that switches the braking force that the swing braking device applies to the turning of the upper swing body in accordance with a designated cart traveling mode.   2. The mobile crane according to claim 1, wherein the counterweight carriage is connected to the upper swing body via the connecting member and supports the counterweight, and a plurality of counterweight carriages attached to the carriage body. A wheel drive device that rotationally drives at least some of the plurality of wheels so that the counterweight cart travels, and a steering device that changes the direction of the plurality of wheels, the cart control unit Is a mobile crane that controls the operation of the wheel drive device and the steering device so as to realize a plurality of cart travel modes preset for the travel of the counterweight cart, respectively.   3. The mobile crane according to claim 1, wherein the plurality of bogie travel modes include a swivel travel mode in which the counterweight bogie travels in a turning direction following the turn of the upper swing body, and the lower A translational travel mode in which the counterweight carriage travels so as to translate with the lower traveling body following the traveling of the traveling body, and the turning braking control unit gives a turning stop holding command in the turning traveling mode. When the upper traveling body is turned, a braking force for holding the turning stop is applied to the turning of the upper traveling body, and at least the counterweight carriage is positioned on the side of the lower traveling body in the translational traveling mode. When the translation is performed, the braking force is reduced so that a translational braking force that is weaker than the turning stop holding braking force is applied to the turning of the upper turning body. Perform, mobile crane.   3. The mobile crane according to claim 1, wherein the swing braking device is configured to apply a first braking force to a swing of the upper swing body and to release the first braking force. 4. A turn parking brake that is selectively switched, a turn positive brake that is a brake different from the turn parking brake, and that applies a braking force corresponding to the input braking force command to the turn of the upper turning body; A braking operation unit that receives an operation for inputting a braking force command and inputs a braking force command corresponding to the operation to the turning positive brake, and a braking force command applied to the turning positive brake is applied to the braking operation unit. A forced braking switching unit that forcibly switches to a braking force command that applies a second braking force that is weaker than the first braking force to the upper swing body regardless of the operation performed. Mobile crane.   5. The mobile crane according to claim 4, wherein the plurality of bogie travel modes include a swivel travel mode in which the counterweight bogie travels in a turning direction following the turning of the upper revolving body and the lower traveling body. A translation traveling mode in which the counterweight carriage travels so as to translate with the lower traveling body following the traveling, and the turning braking control unit is at least when a turning stop holding command is given in the turning traveling mode. When the first braking force is applied to the turning parking brake, and the at least the counterweight carriage is translated with the lower traveling body in the translation traveling mode, the turning parking brake is used. Release the application of the first braking force and actuate the forced braking switching unit to perform the braking operation It said pivoting said the positive brake is applied the second braking force, mobile crane with respect to the pivot of the upper rotating body irrespective of the operation given to.

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