JP2006298524A - Telescopic boom type crawler crane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a telescopic boom type crawler crane structured possible to safely attach/detach a crawler. <P>SOLUTION: This telescopic boom type crawler crane has a lower traveling body capable of travelling with crawlers and an upper turning body provided with a telescopic boom. The crawler can be attached/detached by hoisting the crawler with the telescopic boom in the condition wherein a machine body is floated by a jack-up device provided in the lower travelling body. A hydraulic circuit is provided to supply operating fluid for telescoping a jack-up cylinder 12 of the jack-up device. This telescopic boom type crawler crane has an operation selector valve 17 provided in the hydraulic circuit to switch operation between supply and shut-off of the operating fluid in relation to the jack-up cylinder 11, and has selector means 22, 23 and 24 for switching the operation selector valve by detecting condition of the telescopic boom. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a telescopic boom type crawler crane that does not require the boom to be disassembled even during transportation, and in particular, avoids the danger of falling in a jacked up state when disassembling the crawler or the like using its own telescopic boom. In addition, the present invention relates to a telescopic boom type crawler crane for safely removing and attaching a crawler or the like.

  A crawler traveling type construction machine equipped with a crawler as a traveling means is subjected to size restrictions and weight restrictions when transported by a trailer or the like, and the problem becomes more serious as the machine becomes larger. Therefore, the ordinary lattice boom type crawler crane is configured to be disassembled into a transportable state such that the side frame provided with the crawler can be attached to and detached from the track frame. In general, the boom is disassembled to limit dimensions, the counter is removed for weight restrictions, the boom is removed if not enough, and finally the left and right crawlers are removed. At that time, if another crane for disassembling the crawler crane is required, it is necessary to prepare a crane only for transportation and secure a space for disassembling work. Therefore, a crawler crane that can be attached and detached by itself has been proposed in order to eliminate such a wasteful cost and a work space.

  Here, FIG. 8 is a view showing a crawler crane disclosed in Japanese Patent Laid-Open No. 2003-54876. In the crawler crane, an upper swing body 102 is mounted on a lower traveling body disassembled in the drawing, and a boom 103 is supported on the upper swing body 102 so as to be raised and lowered. In the lower traveling body, a track frame 111 is connected to the upper swing body 102, and a crawler belt is wound around a pair of side frames on both sides of the track frame 111 and a crawler 112 is detachably attached. The boom 103 includes a lower boom 103A and an upper boom (not shown), and the upper boom is divided into a state shown in the figure.

  A winding drum 104 and a undulation drum 105 are mounted on the upper swing body 102. Usually, the hoisting rope 104a wound around the hoisting drum 104 is fed forward through a sheave at the tip of the upper boom and connected to a work hook. Further, the hoisting rope 105 a wound around the hoisting drum 105 is wound around the intermediate sheave (middle sheave) a plurality of times and used for hoisting the boom 103. However, when the crawler 112 is removed and disassembled for transportation, the middle sheave may be pivotally attached to the upper surface of the lower boom, and the lower boom may be raised and lowered.

That is, as for the boom 103, the upper boom is removed from the lower boom 103A, and the hoisting rope 105a is connected in the vicinity of the coupling portion 103a of the lower boom 103A. Then, the hoisting rope 104a of the hoisting drum 104 is stretched through a sheave 106, and a hook 107 is connected to the tip of the rope 104a. In this way, the lifting work near the aircraft can be performed.
In this state, the jack-up cylinder 113 is extended so that the crawler 112 floats from the ground and can be detached from the track frame 111. The position of the sheave 106 is adjusted by the expansion and contraction of the hydraulic cylinder 108, and the crawler 112 is lifted by the hoisting rope 104a through a sling rope (not shown) and separated from the track frame.

The crawler 112 away from the track frame 111 drives the hoisting drum 104 and the undulating drum 105, and the crawler 112 is mounted on a trailer or the like. Subsequently, the upper turning body 102 is turned 180 °, and the other crawler 112 is similarly removed. When the removal of both the crawlers 112 is completed, the trailer bed is placed under the track frame 111, the jackup cylinder 113 is contracted to mount the airframe on the trailer, and the upper swing body 102 faces the longitudinal direction of the trailer. To complete the preparation for transportation.
JP 2003-54876 A (page 3-4, FIG. 5)

  By the way, such a lattice boom type crawler crane has a small working radius if the upper boom is removed and only the lower boom 103A is removed as described above, and a crawler 112 or the like close to the machine body can be suspended. Even in an unstable state that is supported, the work can be performed while preventing overturning. Therefore, the lattice boom type crawler crane can attach and detach the crawler 112 and the like from the truck frame 111 for transportation without using another crane. On the other hand, the lattice boom type crawler crane has to disassemble the boom and has to re-hang the hoisting rope 4a, so that the work is troublesome.

  Therefore, there is an extendable boom type crawler crane that can extend and retract the boom as a solution to the problem of the lattice boom type crawler crane. This crawler crane can suppress the overall length by contracting the boom, and can satisfy the dimensional restrictions in transportation. However, conventional telescoping boom type crawler cranes are limited to those having a weight limit or less so that disassembly is not necessary in transportation in order to take advantage of the advantages. Therefore, since it was only small and medium-sized compared to the lattice boom type crawler crane, there was a limitation in the work content.

  However, the telescopic boom type crawler crane in which the boom can be extended and contracted is more advantageous in the operation of attaching and detaching the crawler during transportation than the lattice boom type crawler crane. This is because when the boom is contracted, the working radius becomes small, and when performing the attaching / detaching operation of the crawler or the like, it is not necessary to disassemble the boom for the disassembling work unlike the lattice boom type crawler crane. Then, by not disassembling the boom, it is not necessary to perform the troublesome work of re-hanging the wire rope from the winding drum. Therefore, conventionally, there has been a great demand for using a large telescopic boom type crawler crane because of the convenience of not having to divide the boom. However, large telescopic boom type crawler cranes are heavy, and the weight of the telescopic boom is heavy, so it is unstable to jack up the main body even in a no-load state where the load is not suspended. When it was lifted with its own telescopic boom, it became more unstable and there was a risk of falling.

  Then, this invention aims at providing the telescopic boom type crawler crane for performing attachment or detachment of a crawler etc. safely in order to solve this subject.

  The telescopic boom type crawler crane according to the present invention has a lower traveling body that can be traveled by a crawler and an upper revolving body provided with an telescopic boom, and the aircraft body is floated by a jack-up device provided on the lower traveling body. The crawler is lifted by a telescopic boom so that it can be attached and detached, and is provided with a hydraulic circuit that supplies hydraulic oil for expanding and contracting the jackup cylinder of the jackup device. And an operation switching valve provided in the hydraulic circuit for switching between supply and shutoff of the hydraulic oil, and switching means for detecting the state of the telescopic boom and switching the operation switching valve.

In the telescopic boom type crawler crane according to the present invention, the switching means preferably detects the length of the telescopic boom, or detects the length and angle of the telescopic boom.
Moreover, it is preferable that the telescopic boom type crawler crane according to the present invention alarms or automatically stops with respect to an overload state of the crane capacity in a state where the jack-up cylinder is extended.
Further, the telescopic boom type crawler crane according to the present invention has a moment limiter capable of switching the overturning fulcrum by switching between the normal work mode and the disassembly work mode, and the switching means detects the mode switching. It is preferable that

  Therefore, according to the telescopic boom type crawler crane according to the present invention, the jack-up cylinder is extended to lift the airframe, and in such a state, the crawler is lifted with its telescopic boom to perform the attaching / detaching operation. Even in the relatively unstable state supported by the jack-up device, the switching means detects the length and angle of the telescopic boom and switches the supply and shut-off of hydraulic oil to the jack-up cylinder by the operation switching valve. When there is a danger of falling in an unloaded condition, the jackup cylinder does not extend and cannot be disassembled.Also, after jacking up, a warning is issued when a load exceeding the crane capacity in that condition is lifted. Or automatically stop the operation on the dangerous side, so the crawler can be disassembled only in a safe state.

Next, one embodiment of the telescopic boom type crawler crane according to the present invention will be described below with reference to the drawings. FIG. 1 to FIG. 5 are views showing an assembly state of the telescopic boom type crawler crane transported to the construction site by a trailer.
First, the structure of the telescopic boom type crawler crane will be described with reference to FIG. An extendable boom type crawler crane (hereinafter simply referred to as a “crawler crane”) 1 is provided with an upper swing body 3 that can pivot on a lower traveling body 2. The upper swing body 3 is configured to be rotatable with respect to the lower traveling body 2 by a swing device, and the partial swing body 3 is provided with a driver's cab, a winch, a power device, and the like.

  Further, the upper revolving body 3 is provided with a telescopic telescopic boom 5 supported by a hoisting cylinder 4, and the hoisting cylinder 5 elongates and stands up as shown by a two-dot chain line in FIG. It is possible to undulate between states. The telescopic boom 5 is configured such that four-stage booms having a box-shaped cross section are overlapped and contracted as shown in the figure, and are slid and extended. The lower traveling body 2 is provided with outriggers as jack-up devices at four locations on the front, rear, left and right sides so as to project from both sides in the left-right direction.

  The outrigger is expanded and contracted by a jack-up cylinder, and is used to lift the airframe when the crawler is removed during transportation. On the other hand, there is no need to remove the crawler when transporting the premises, so the crawler is loaded directly onto the trailer for transport. At that time, the crawler width (span) is related to the load width of the trailer. Need to be narrowed. For this reason, a crawler expansion / contraction cylinder is provided so that the position of the crawler in the width direction can be adjusted, and the crawler can be pulled toward the machine body according to the loading width of the trailer. FIG. 6 is a diagram showing a hydraulic circuit for operating such a jack-up cylinder and a crawler expansion / contraction cylinder.

  The lower traveling body 2 includes a pair of left and right crawler expansion / contraction cylinders 11A and 11B ("crawler expansion / contraction cylinder 11" when collectively described) and front and rear, left and right jack-up cylinders 12A, 12B, and 12C as illustrated. , 12D (“jack-up cylinder 12” when collectively described) is provided. The crawler expansion / contraction cylinder 11 and the jackup cylinder 12 are hydraulic cylinders, and the lower traveling body 2 on the right side of the drawing is provided with various valves for switching the supply of hydraulic oil to them. On the other hand, a hydraulic pump 31 and a tank 32 are provided in the upper revolving unit 3 on the left side of the drawing, and a rotary joint (not shown) is provided between the upper revolving unit 1 and the lower traveling unit 2, and is configured via the rotary joint. They are connected by three lines 51, 52, 53.

  On the upper swing body 3 side, there are provided a hydraulic pump 31 for feeding hydraulic oil to various hydraulic devices and a tank 32 for storing hydraulic oil for driving various hydraulic devices. Such hydraulic pump 31 and tank 32 and crawler expansion / contraction A main switching circuit 33 is provided between various hydraulic devices such as the cylinder 11 and the jack-up cylinder 12. The main switching circuit 33 is provided with a plurality of main switching valves 34, of which the uppermost one shown corresponds to the crawler expansion / contraction cylinder 11 and jackup cylinder 12, and is connected via lines 51, 52, 53. ing.

  The main switching valve 34 is provided with four switching ports, and is configured to operate the spool by switching the pilot solenoid valves 34m and 34n to switch between the illustrated cross port connection and parallel port connection. . This is because the pilot solenoid valves 34m and 34n are operated by an operation from the cab, thereby switching the main switching valve 34. A supply line 54 from the hydraulic pump 31 is connected to a line 51 directly connected to the tank 32 via a relief valve 35, while a plurality of main switching valves 34 are respectively connected via check valves 36. It is connected. Lines 52 and 53 are connected to the main switching valve 34, and the switching of the hydraulic pump 31 with respect to the lines 52 and 53 is switched by a cross port connection and a parallel port connection.

By the way, the crawler crane 1 of this embodiment is configured to manually perform the expansion / contraction operation of the jack-up cylinder 12, and the expansion / contraction operation of the crawler expansion / contraction cylinder 11 is performed not only manually but also from the driver's seat. It is configured to be able to. Therefore, on the lower swing body 2 side, the operation valves 13A and 13B connected to the crawler expansion / contraction cylinder 11 for manual operation (referred to as “operation valve 13” when collectively described) and the lockup cylinder 12 are provided. Connected operation valves 14A, 14B, 14C, and 14D (when collectively described, they are referred to as “operation valve 14”) are provided.
The crawler expansion / contraction cylinder 11 and the check-up cylinder 12 have pilot check valves 15a1, 15a2, 15b1, 15b2 and pilot check valves 16a, 16b that control the flow of hydraulic oil during expansion / contraction operation and maintain the stroke during non-extension / contraction. , 16c, 16d are provided.

  Further, in the present embodiment, an operation switching valve 17 that switches operation between the crawler expansion / contraction cylinder 11 and the lockup cylinder 12 is provided. The operation switching valve 17 is a four-port solenoid valve, and can be switched between a cross port connection and a parallel port connection shown in the figure. The operation switching valve 17 is in the normal position when the illustrated parallel port connection is not energized, and the circuit is configured so that hydraulic oil does not flow to the jack-up cylinder 12 side in this state. Between the operation switching valve 17 and the power source 21, a length detection switch 22 for detecting the length of the telescopic boom 5, an angle detection switch 23 for detecting the angle of the telescopic boom 5, and a crawler are attached and detached. Disassembly mode switch 24 is provided in series.

When the crawler crane 1 is supported by the outriggers, if the telescopic boom 5 is extended or falls over a certain angle, the center of gravity moves to the outside and there is a risk of falling. The length detection switch 22 and the like are provided to detect such a risk of falling and prevent the hydraulic oil from flowing to the jackup cylinder 12 side.
The length detection switch 22 and the angle detection switch 23 are installed so that, for example, when the telescopic boom 5 is less than a predetermined length or when it stands up more than a predetermined angle, it is turned on. It is a limit switch. When the crawler is attached or detached, the telescopic boom 5 is usually the shortest length, and the crawler crane 1 of this embodiment has the telescopic boom 5 as shown by a two-dot chain line in FIG. There is no risk of falling even if it is level. Therefore, if the telescopic boom 5 is operated only when it has the shortest length, only the length detection switch 22 may be used.

  Further, the danger of the crawler crane 1 falling over is not only during the crawler disassembly work but also during normal work with the crawler attached. On the other hand, the crawler crane 1 has conventionally been provided with a moment limiter as a safety device, and is also installed in the crawler crane 1 of the present embodiment. Since this moment limiter performs safety control based on the overturning fulcrum of the crawler crane 1 in the normal work state with the crawler mounted, it cannot be used as it is when the crawler is supported by the outrigger. Therefore, in this embodiment, by switching between the normal work mode and the disassembly work mode, the overturning fulcrum of the moment limiter can be changed to the position of the outrigger by the mode switch during disassembly work. The disassembly mode switch 24 is interlocked with such a mode changeover switch (not shown) so as to be turned on in the disassembly mode.

Next, the operation of the crawler crane 1 of the present embodiment will be described, particularly the crawler detachment associated with transportation. Here, the operation | work at the time of mounting | wearing of the crawler by the crawler crane 1 is demonstrated based on FIG. 1 thru | or FIG.
The crawler crane 1 transported by the trailer 60 is mounted with the left and right crawlers removed and the track frame placed directly on the trailer 60. Immediately after carrying in, the telescopic boom 5 is tilted horizontally as shown by a two-dot chain line in FIG. 1, but the hoisting cylinder 4 is extended and raised as shown by a solid line in preparation for mounting the crawler. The front, rear, left and right jackup cylinders 12 are extended in a state in which safety against falling is ensured. The safety confirmation accompanying the extension of the jackup cylinder 12 will be described later.

  The crawler crane 1 supported by the jack-up cylinder 12 is in a state where the machine body is lifted from the trailer 60. Therefore, the trailer 60 is moved as shown in FIG. In this way, when the space under the crawler crane 1 is empty, the jack-up cylinder 12 is contracted, and the machine body is lowered to an appropriate height for mounting the crawler. Therefore, as shown in FIGS. 3 and 4, the crawler 6 is suspended while the telescopic boom 5 is set to the shortest length, and is moved and set with respect to the track frame 7. When both the crawlers 6 have been mounted, the jack-up cylinder 12 is contracted to the shortest length as shown in FIG. On the other hand, in order to obtain the transport state shown in FIG. 1 with the crawler 6 removed from the working state, the above operation may be performed in reverse.

  The jack-up cylinder 12 is extended to support the crawler crane 1 with respect to the attachment / detachment of the crawler 6, but in this embodiment, the work can be safely performed even in a relatively unstable state with the crawler 6 removed. ing. In other words, the jack-up cylinder is configured not to extend in a state where there is a possibility of falling, and in the state where the crawler is lifted, if the crane capacity at the working radius is exceeded, an alarm is sounded or the danger side This is because the operation is automatically stopped. Next, the expansion and contraction of the jackup cylinder 12 will be described with reference to FIG.

  The expansion and contraction of the jack-up cylinder 12 is performed while adjusting a small amount manually. That is, the jack-up cylinder 12 can be extended or contracted or stopped at a predetermined stroke by the switching operation of the operation valve 14. For this purpose, the main switching valve 34 is switched to the parallel port connection on the upper swing body 3 side. Accordingly, the hydraulic oil sent from the tank 32 by the hydraulic pump 31 and flowing to the supply line 54 is pressure-adjusted by the relief valve 35 and flows through the supply line 54a to be sent from the check valve 36 to the main switching valve 34. Since the switching valve 34 has a parallel port connection, the hydraulic oil flows to the line 53 and is sent to the operation switching valve 17 of the lower swing body 2.

  At this time, if any one of the length detection switch 22, the angle detection switch 23, and the disassembly mode switch 24 between the operation switching valve 17 and the power source 21 is in the OFF state, the operation switching valve 17 is in the normal state shown in the figure. It remains in position, ie parallel port connection. Such a situation is a case where the telescopic boom 5 is not the shortest length but is extended or the operator does not turn on the disassembly mode switch 24. In such a case, the hydraulic oil flowing through the line 53 flows to the line 55 and is supplied only to the crawler expansion / contraction cylinder 11 side. Accordingly, the hydraulic oil is not supplied to the jack-up cylinder 12, so that the crawler 6 cannot be detached.

  Therefore, when the telescopic boom 5 is extended, it is shortened to the shortest length as shown in FIG. As a result, the length detection switch 22 and the angle detection switch 23 are turned on. Further, when the disassembly mode switch 24 is turned on by the operator and turned on, the solenoid of the operation switching valve 17 is energized and switched from the no-pal position to establish a cross-port connection. Therefore, the hydraulic oil fed from the line 53 by the hydraulic pump 31 flows to the line 56 connected to the operation valves 13 and 14 by the cross port connection of the operation switching valve 17. The flow rate and fluid pressure of the hydraulic oil flowing through the line 56 are adjusted by the flow rate adjustment valve 25 and the relief valve 26.

  The jack-up cylinder 12 performs stroke adjustment by switching the port connection from the neutral state shown in the figure by manual operation of the operation valve 14. Therefore, when the jackup cylinder 12 is extended, the operation valve 14 is switched to the cross port connection. When looking at the jack-up cylinder 12D and the operation valve 14D (the same applies to the other jack-up cylinders 12), the working fluid whose flow rate and pressure are adjusted through the line 56 is operated through the check valve 27. Enter valve 14D and flow to line 57. The hydraulic oil flows through the pilot check valve 16d as it is to pressurize the head side of the jackup cylinder 12D, and the piston is pressurized to extend the jackup cylinder 12D. Accordingly, the hydraulic oil discharged from the rod side flows through the line 58 to the operation valve 14D because the pilot check valve 16d is opened by the fluid pressure. Then, the discharged hydraulic oil flows from the operation valve 14D through the line 59 and flows to the tank 32 through the connected line 51.

  On the other hand, when the jackup cylinder 12 is contracted, the operation valve 14 is switched to the parallel port connection. Therefore, when looking at the jack-up cylinder 12D and the operation valve 14D (the same applies to the other jack-up cylinders 12), the working fluid whose flow rate and pressure are adjusted through the line 56 is operated through the check valve 27. It enters valve 14D and flows to line 58. The hydraulic oil flows through the pilot check valve 16d as it is to pressurize the rod side of the jackup cylinder 12D, and the piston is pressurized to contract the jackup cylinder 12D. Accordingly, the hydraulic oil discharged from the head side flows through the line 57 to the operation valve 14D because the pilot check valve 16d is opened by the fluid pressure. Then, the discharged hydraulic oil flows from the operation valve 14D through the line 59 and flows to the tank 32 through the connected line 51.

In this way, all the jack-up cylinders 12 are expanded and contracted by manual operation of the operation valve 14, and the operation valve 14 is neutralized with an appropriate length and stopped at a predetermined stroke. 1 to 5, the operation of extending the jack-up cylinder 12 in FIG. 1, contracting in FIG. 2, and contracting to the shortest length in FIG. 5 is performed.
During the disassembly operation, the moment limiter is switched from the normal operation mode to the disassembly operation mode, the overturning fulcrum is changed to the outrigger position, and the telescopic boom 5 can be tilted only to a safe angle even when the crawler is lifted, and the winch However, it will not wind up any further.

Therefore, in the crawler crane 1 of the present embodiment, the length detection switch 22 and the angle detection switch 23 are not turned on and the operation switching valve 17 cannot be switched unless the length and angle of the telescopic boom 5 satisfy predetermined conditions. In a state where there is a risk of falling, the jackup cylinder 12 cannot extend and support the machine body, and the crawler 6 and the like can be disassembled in a safe state.
In addition, since the length detecting switch 22 and the angle detecting switch 23 are configured by using limit switches as switching means for switching the operation switching valve 17, the above effect can be achieved with an inexpensive device. .

  In the crawler crane 1 of the present embodiment, the disassembly mode switch 24 is linked to a mode change switch (not shown), and the operation switching valve 17 cannot be switched unless the operator switches the mode in the disassembly mode. The moment limiter is always switched from the normal operation mode to the disassembly operation mode. Therefore, when the work is disassembled, the overturning fulcrum of the moment limiter is changed to the outrigger position so that the jackup cylinder does not extend when there is a possibility of overturning in a no-load condition, and the crawler is lifted after jacking up. In a state where the crane capacity at the working radius is exceeded, the dangerous side operation (boom down and winch hoisting) is automatically stopped, and the crawler 6 and the like can be disassembled in a safe state. .

  Next, the expansion / contraction operation of the crawler expansion / contraction cylinder 11 will be described based on the hydraulic circuit shown in FIG. During the disassembling operation described above, the main switching valve 34 on the upper swing body 3 side is switched to the parallel port connection. Therefore, the hydraulic oil sent from the tank 32 by the hydraulic pump 31 and flowing through the line 54 a is sent to the line 53 through the main switching valve 34 and flows to the operation switching valve 17 of the lower swing body 2. At the time of the above-described disassembling operation, since the operation switching valve 17 is switched to be in a cross-port connection, the hydraulic oil flowing through the line 53 is sent to the line 56, and the neutral operation valve shown in the figure via the line 56a. It flows to 13A and 13B.

  Therefore, when the operation valves 13A and 13B are switched to the cross port connection, the working fluid whose flow rate and pressure are adjusted through the line 56 flows to the lines 61 and 63 through the operation valves 13A and 13B, respectively. The hydraulic fluid flows through the pilot check valves 15a2 and 15b2 as it is to pressurize the head side of the crawler expansion / contraction cylinders 11A and 11B, and the piston is pressurized to extend the crawler expansion / contraction cylinders 11A and 11B. Accordingly, the hydraulic oil discharged from the rod side flows to the operation valves 13A and 13B through the lines 62 and 64 because the pilot check valves 15a2 and 15b2 are opened by the fluid pressure. The discharged hydraulic oil flows through the line 59 and flows to the tank 32 through the connected line 51.

  Conversely, when the operation valves 13A and 13B are switched to the parallel port connection, the working fluid whose flow rate and pressure are adjusted through the line 56 flows to the lines 62 and 64 through the operation valves 13A and 13B, respectively. The hydraulic fluid flows through the pilot check valves 15a2 and 15b2 as it is to pressurize the rod side of the crawler expansion / contraction cylinders 11A and 11B, and the piston is pressurized to contract the crawler expansion / contraction cylinders 11A and 11B. Accordingly, the hydraulic oil discharged from the head side flows to the operation valves 13A and 13B through the lines 61 and 63 because the pilot check valves 15a2 and 15b2 are opened by the fluid pressure. The discharged hydraulic oil flows through the line 59 and flows to the tank 32 through the connected line 51.

Next, a case where the crawler expansion / contraction cylinders 11A and 11B are operated at the driver's seat during normal work with the crawler mounted to change the left and right intervals of the crawler 6 will be described. In this case, the pilot solenoid valves 34m and 34n can be operated by an operation from the cab and the main switching valve 34 can be switched. It should be noted that the operation switching valve 17 on the lower traveling body 2 side remains in the illustrated normal position.
Therefore, when the crawler expansion / contraction cylinders 11A and 11B are extended, the main switching valve 34 is switched to the cross port connection. Then, the hydraulic oil sent from the tank 32 by the hydraulic pump 31 and flowing through the line 54 a is sent to the line 52 through the main switching valve 34.

  The hydraulic fluid flowing through the line 52 flows through the directly connected line 65 to the pilot check valves 15a1 and 15b1. In the pilot check valves 15a1 and 15b1, the hydraulic fluid flows as it is to pressurize the head side of the crawler expansion / contraction cylinders 11A and 11B, and the piston is pressurized to extend the crawler expansion / contraction cylinders 11A and 11B. Accordingly, the hydraulic oil discharged from the rod side flows to the operation switching valve 17 through the line 55 because the pilot check valves 15a1, 15b1 are opened by the fluid pressure. Then, the hydraulic oil flows through the line 53, is sent from the main switching valve 34 of the upper swing body 3 to the line 66, and further flows through the line 51 to the tank 32.

  On the other hand, when the crawler expansion / contraction cylinders 11A and 11B are extended, the main switching valve 34 is switched to the parallel port connection. Then, the hydraulic oil sent from the tank 32 by the hydraulic pump 31 flows to the line 53 through the main switching valve 34. Then, it flows to the line 55 through the operation switching valve 17 in the normal position shown in the figure, pressurizes the rod side of the crawler expansion / contraction cylinders 11A, 11B via the pilot check valves 15a1, 15b1, and pressurizes the piston to crawler expansion / contraction cylinder. 11A and 11B contract. Accordingly, the hydraulic oil discharged from the head side flows to the line 65 because the pilot check valves 15a1 and 15b1 are opened by the fluid pressure. Then, it flows to the line 52 directly connected to the line 65, is sent from the main switching valve 34 of the upper swing body 3 to the line 66, and flows to the tank 32 through the line 51.

In the above embodiment, as shown in FIG. 6, the operation switching valve 17 and the length detection switch 22 serving as switching means are provided on the lower traveling body 2 side. It can also be provided on the side. FIG. 7 is a diagram showing a hydraulic circuit for operating a jack-up cylinder or a crawler expansion / contraction cylinder having another configuration. The same components as those in the embodiment shown in FIG.
Here, the main switching valve 34 of FIG. 6 is an operation switching valve (hereinafter referred to as “operation switching valve 34”), and a manual valve 18 is provided in place of the operation switching valve 17. The pilot solenoid valves 34m and 34n of the operation switching valve 34 are connected to the power source 21 via a spanner switch 28 that can be switched in the cab. In particular, a length detection switch 22, an angle detection switch 23, and a disassembly mode switch 24, which are switching means, are connected in series to the electromagnetic valve 34n.

The expansion / contraction of the jack-up cylinder 12 can be extended or contracted by stopping the operation valve 14 or stopped at a predetermined stroke. To this end, the spanner switch 28 is switched to the electromagnetic valve 34n side on the upper swing body 3 side, and the manual valve 18 is switched to the cross port connection on the lower traveling body 2 side.
At this time, if any one of the length detection switch 22, the angle detection switch 23, and the disassembly mode switch 24 between the electromagnetic valve 34n and the power source 21 is in the OFF state, the operation switching valve 34 is in the normal position shown in the figure. That is, the port is left disconnected. Accordingly, the hydraulic oil is not supplied to the lower traveling body 2 side, so that the crawler 6 cannot be detached.

  On the other hand, when the length detection switch 22, the angle detection switch 23, and the disassembly mode switch 24 are turned on, the solenoid of the electromagnetic valve 34n is energized and the operation switching valve 34 is switched to the parallel port connection. Therefore, the working fluid supplied by the hydraulic pump 31 flows to the line 53 through the operation switching valve 34 and flows to the line 56 connected to the operation valves 13 and 14 by the cross port connection of the manual valve 18. In this way, the jack-up cylinder 12 performs stroke adjustment by switching the port connection from the neutral state shown in the figure by manual operation of the operation valve 14. When the jackup cylinder 12 is extended, the operation valve 14 is switched to the cross port connection. On the other hand, when the jackup cylinder 12 is contracted, the operation valve 14 is switched to the parallel port connection.

As mentioned above, although one Embodiment of the telescopic boom type crawler crane which concerns on this invention was described, this invention is not limited to this, A various change is possible in the range which does not deviate from the meaning.
In the above embodiment, the length detection switch 22 and the angle detection switch 23 are used to support the machine body with the jack-up cylinder 12 from the expansion and contraction state and angle of the telescopic boom 5. However, as described above, when the telescopic boom 5 has the shortest length, there is a possibility that there is no danger of falling out of balance even when the boom 5 is lying down. Therefore, the determination may be made only by the length detection switch 22.

Further, for example, in the above-described embodiment, the normal position of the operation switching valve 17 on the lower traveling body 2 side is configured as a parallel port connection, but the normal position is configured as a flat cross port connection, and the length detection switch 22 and the angle detection switch are configured. You may make it comprise 23 as b contact.
In the above embodiment, the length detection switch 22 and the angle detection switch 23 are configured using reed switches. However, the length and angle of the telescopic boom are measured by measuring the state of the telescopic boom using a length meter and an angle meter. It is also possible to switch the operation switching valve 17 based on a composite determination.

It is the figure which showed the time of jackup cylinder extension at the time of the assembly operation of the telescopic boom type crawler crane conveyed to the construction site. It is the figure which showed the support state by the jackup apparatus at the time of the assembly operation of the telescopic boom type crawler crane conveyed to the construction site. It is the figure which showed the crawler lifting state at the time of the assembly operation of the telescopic boom type crawler crane transported to the construction site. It is the figure which showed the crawler mounting state at the time of the assembly operation of the telescopic boom type crawler crane conveyed to the construction site. It is the figure which showed the state at the time of the assembly completion of the expansion-contraction boom type crawler crane conveyed to the construction site. It is the figure which showed the hydraulic circuit which operates the jackup cylinder and the crawler expansion-contraction cylinder in the telescopic boom type crawler crane of embodiment. It is the figure which showed the hydraulic circuit which operates the jackup cylinder and the crawler expansion-contraction cylinder in the telescopic boom type crawler crane of embodiment. It is the figure which showed the conventional lattice boom type crawler crane.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Telescopic boom type crawler crane 2 Lower traveling body 3 Upper turning body 4 Hoisting cylinder 5 Telescopic boom 11 (11A, 11B) Crawler expansion / contraction cylinder 11 (12A, 12B, 12C, 12D) Jack up cylinder 13 (13A, 13B) Operation valve 14 (14A, 14B, 14C, 14D) Operating valve 15a1, 15a2, 15b1, 15b2 Pilot check valve 16a, 16b, 16c, 16d Pilot check valve 17 Operation switching valve 21 Power supply 22 Length detection switch 23 Angle detection switch 24 Disassembly mode Switch 31 Hydraulic pump 32 Tank 34 Main switching valve

Claims (4)

The crawler has a lower traveling body that can travel by a crawler and an upper revolving body with a telescopic boom, and the crawler can be lifted and removed by the telescopic boom in a state where the airframe is lifted by a jackup device provided on the lower traveling body In a telescopic boom type crawler crane provided with a hydraulic circuit for supplying hydraulic oil for expanding and contracting the jack-up cylinder of the jack-up device,
An operation switching valve provided in the hydraulic circuit for switching between supplying and shutting off hydraulic oil to the jackup cylinder, and switching means for detecting the state of the telescopic boom and switching the operation switching valve. A telescoping boom type crawler crane. In the telescopic boom type crawler crane according to claim 1,
The switching means detects the length of the telescopic boom, or detects the length and angle of the telescopic boom. In the telescopic boom type crawler crane according to claim 1 or 2,
A telescopic boom type crawler crane that warns or automatically stops when an overload of the crane capacity occurs when the jack-up cylinder is extended. In the telescopic boom type crawler crane according to any one of claims 1 to 3,
A telescopic boom type crawler having a moment limiter capable of switching overturning fulcrums by switching between a normal work mode and a disassembly work mode, wherein the switching means is also adapted to detect mode switching. crane.

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