JPH10139377A - Safety device of walking crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent a fall accident of a jib by controlling to stop crane work or a part of the operation, or give a warning by a warning means according to the status of a lock pin insert detector, a jib housing completion detector, and an upper part work mode switch for selecting a work mode. SOLUTION: One of a single top mode, a jib mode, a preparation mode is selected by an upper work mode switch 71, lock pin insertion is detected by a lock pin insert detector 70, and it is detected by a jib housing completion detector 33b that the jib is located in the housing position. According to the status of the switch 71 and the detectors 70, 33b depending on the detection signals, crane work or partial operation is stopped by a moment limiter controller 52 or a warning is given by a buzzer and displayed on a moment limiter display panel 40. Thus, it is possible to prevent a fall of a jib due to forgetting to insert a pin while the jib is projected and housed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for a mobile crane, and more particularly to a mobile crane that checks the erroneous operation of a work mode switch and the working condition of the mobile crane to prevent the jib from falling. The present invention relates to a safety device for a crane.

[0002]

2. Description of the Related Art A mobile crane is provided with a telescopic boom on a vehicle body so as to be able to move up and down and swing freely. However, when it is necessary to expand the workable range by each of the above-mentioned expansion, contraction, undulation, and turning operations, a jib-mounted mobile crane that can expand the workable range by attaching a jib to the end of the boom is used. used. As a prior art of such a jib-mounted mobile crane, for example, as shown in FIGS. 24 to 33, as a first prior art, Japanese Utility Model Laid-Open No. 5-44990, and as a second prior art There is "Japanese Utility Model Laid-Open No. 6-76283".

In the first and second prior arts, an upper revolving structure 8 is provided so as to be rotatable at an upper portion substantially at the center of a lower traveling structure 1 having wheels in front, rear, left and right in FIG. A flexible boom 3 is provided so that it can be raised and lowered. Also,
A driver's cab 9 in which a traveling operation and a work machine operation can be performed is disposed on a front side surface of the upper revolving superstructure 8. The boom 3 is a multi-stage telescopic boom, and includes a base boom 4 to a top boom 6. A jib 7 is mounted on the side surface of the boom 3 when the mobile crane travels. This jib 7
At the time of work, it is rotated around the lock pin (19a) shown in FIG. 29 as necessary, so that it protrudes from the side surface of the boom 3 to the boom tip and is connected to the boom tip as shown in FIG. Has become.

The extension and storage of the jib 7 in such a jib-mounted mobile crane will be described in detail with reference to the drawings. 25 is a plan view showing the stored state of the jib 7, FIG. 26 is a detailed plan view of the connecting portion between the top boom 6 and the jib 7 in FIG. 25, and FIG. 27 is a side view of the connecting portion in the extended state. A lug 81 for fixing the jib 7 is provided at a rear portion of the side surface of the base boom 4, and a lug 82 provided at the tip of the jib 7 is connected to the lug 81 by a pin 83. A lug 85 is provided at the center of the side surface of the base boom 4, and two lugs 84 provided at the center of the jib 7 are locked to the lug 85 and connected by pins 80.

As shown in FIG. 26, lugs 87a and 87b are provided on the left and right sides of the tip side of the top boom 6, and lugs 87a and 87b of the top boom 6 are connected to the jib 7 at the base end of the jib 7. Lock pins 19a and 19b are provided. Lock cylinders 17 and 18 for attaching and removing the lock pins 19a and 19b are attached. On the upper surface of the base end of the jib 7, the rotation cylinder 63 for swinging out the jib 7 (rotating the jib 7 around the pin 80), extending and storing the tube is rotated by the pin 99 on the tube side. It is provided freely. The rod side of the rotary cylinder 63 is rotatably connected to a link between the link 92 and the link 93 by a pin 96. Link 9
The other end of 3 is rotatably attached to the upper surface of jib 7 by a pin 97, and the other end of link 92 is rotatably attached to the upper surface of jib 7 by a pin 94 during storage.

A switch box 89 is provided on the top surface of the top boom 6. The switch box 89 houses switches (not shown) for operating the lock cylinders 17 and 18 and the rotating cylinder 63. Further, a pin 83 for fixing the jib 7 to the base boom 4, a pin 80, and a pin 9 for fixing the link 92.
4. The pins 98 and the like are positioned so that they can be easily inserted and removed from the upper surface of the top boom 6.

[0007] The second prior art is different from the first prior art in that a lug 85 provided on the side surface of the base boom 4 and a jib 7 as shown in FIG. A limit switch 86 for detecting a pin 80 connecting the pinion 84 is installed on the base boom 4. Further, as shown in FIG. 32B, a limit switch 88 for detecting a pin 83 connecting a lug 81 provided on the side surface of the base boom 4 and a lug 82 provided on the jib 7 as shown in FIG. Is installed on the base boom 4. As shown in FIG. 33, the drive circuit of the telescopic cylinder 141 for the top boom 6 includes a direction switching valve 1 on the extension side of the top boom 6.
A solenoid valve 147 for opening and closing the 43 pilot circuit is provided. These limit switches 86, 88
A circuit in which normally open contacts and normally closed contacts are connected in series, respectively, is connected in parallel, and a circuit is connected between the power supply 90 and the solenoid valve 147 in series.

[0008] The first prior art and the second prior art operate as follows. As shown in FIG. 26, when the jib is overhanging, the operator first gets on the upper surface of the top boom 6 and pulls out the pin 94 attaching the link 92 to the jib 7. Then, the switch of the switch box 89 is operated to operate the rotary cylinder 63 so that the hole at the distal end of the link 92 matches the hole 95 provided at the upper surface side end of the top boom 6,
The pin 98 is inserted into the hole 95 to connect the link 92 to the top boom 6. Next, the pin 83 that fixes the tip end of the jib 7 shown in FIG. 25 to the base boom 4 is pulled out, and the rotating cylinder 63 is operated by the switch box 89, and FIG.
8. As shown in FIG. 29, the jib 7 is swung around the pin 80, and the lock pin 19a at the base end of the jib 7 is aligned with the hole of the lug 87a at the tip of the top boom 6. In this state, the lock pin 19a is inserted by operating the lock cylinder 17 shown in FIG. 27, and the lug 87a is connected to the jib 7. Thereafter, the pin 80 fixing the two pieces 84 at the center of the jib 7 is pulled out, and the boom 3 is extended by the operation lever in the cab 9 as shown in FIG. Remove 84 from lug 85. As a result, the jib 7 is supported by the lock pin 19a and the pin 98.

Next, the operating lever in the driver's seat 9 or the switch in the switch box 89 is operated to operate the rotating cylinder 63 to rotate the jib 7 around the lock pin 19a, as shown in FIG. To the front of the boom 3 as shown. Lock cylinder 18 by switch box 89
To lock the lock pin 19b to the lug 8 of the top boom 6.
7b. Thereby, the connection work between the jib 7 and the top boom 6 is completed. The work of storing jib 7
Perform the procedure in the reverse order. In this way, the operator operates the cylinders and the working machines in the operator's cab 9 or on the top of the top boom 6 to extend and store the jib 7. At the same time, the worker completes each work process, for example, the lock pin 19a
After confirming at the upper part of the top boom 6 that the plug has been securely inserted into the hole, the process proceeds to the next step.

In FIG. 33, when one of the pins 80 and 83 is inserted, the telescopic cylinder 15 never extends, so that the jib 7 and the lug 81 are operated even if the operation valve of the top boom 6 is erroneously operated. , 82, 84, 85, etc., are prevented.

[0011] A third prior art is different from the first and second prior arts in that two pieces 84 of the jib 7 are installed on the upper and lower sides, and each hole through which the two pieces 84 penetrate is installed on the lug 85. The configuration is such that the pins 80 are omitted, thereby greatly simplifying the operation of extending and storing the jib 7.

[0012]

However, the first and second prior arts have the following problems. (1) In the case of the jib overhanging and storage device, the worker often needs to be on the boom 3 and work.
There is always the danger of working at heights and in narrow places. (2) For some work processes, it is very important to confirm the completion of the process. For example, if the pin 80 is pulled out and the boom 3 is extended in a state where the lock pin 19a is not completely inserted when the lock pin 19a is inserted into the hole of the lug 87a by operating the lock cylinder 17, the connection between the boom 3 and the jib 7 is released. There is a risk that the jib 7 will fall. (3) When the jib 7 is stored, the two pins 84 and the lugs 85
If the lock pin 19a is pulled out in a state where the jib 7 is not connected, there is a danger that the jib 7 will similarly fall. (4) In such a process, it is necessary to securely confirm the completion of the process (pin insertion completed). However, since the conventional method relies on the confirmation of the operator, the burden on the operator becomes too large, In addition to increasing fatigue, if this confirmation is insufficient by mistake, the above-mentioned accident may occur.

The third conventional technique has the following problems. (5) When the jib 7 is retracted, the jib foot pin 83 is pulled out, and then the jib storage pin 83 is forgotten to be inserted. (6) When the jib is stored during maintenance, the jib storage pin 83 is pulled out for work. (7) If the jib storage pin 83 has been pulled out due to mischief when the jib is stored, in this case, the jib 7 is dropped when the boom 3 is extended since the interlock is not detected by detecting this. There was a fear of doing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. The present invention has been made to improve the safety by reducing the work of the operator on the boom and to improve the jib by insufficiently confirming the completion of the pin connection. An object of the present invention is to provide a safety device for a mobile crane that prevents the occurrence of a fall accident or the like and that checks the crane working state.

[0015]

To achieve the above object, a safety device for a mobile crane according to the first invention of the present invention comprises a telescopic boom 3 and a side of the boom 3. The jib 7 supported and stored by the fixing means 30 and the bracket 7 and the boom 3 of the jib 7
A lock pin 19a which enters and exits one of the right and left brackets 61, and is stored on the side of the boom 3 around the lock pin 19a inserted into the bracket 15 and the bracket 61 when the jib 7 is used. In a safety device for a mobile crane that rotates the extended jib 7 in front of the boom 3 to extend it,

The lock pins 19a are connected to the brackets 15,16.
Lock pin insertion detector 70 for detecting insertion into
And a jib storage pin 33 inserted into the hole 31a of the fixing means 30 to fix the jib 7 stored in the boom 3.
Jib storage completion detectors 33b and 33c for detecting that the jib storage pin 33 is inserted into the hole 31a or that the jib 7 is at the jib storage position, and a boom or single top at the storage position of the jib 7 Mode, the jib mode at the overhang position of the jib 7, the overhang of the jib 7,
An upper operation mode switch 71 for selecting one of the operation modes of the preparation mode for performing the storing operation;
0, 33b, and 33c, and a controller 52 that stops the crane operation or a partial operation thereof according to the state of the switch 71, or warns by an alarm unit.

According to the first aspect, the jib 7 is prevented from falling due to forgetting to insert the storage pin 33 when the jib is stored. Prevents the jib 7 from falling due to forgetting to insert the lock pin 19a and the storage pin 33 during the jib overhang and the storage operation. It warns that the upper work mode switch 71 has been incorrectly set to the boom mode with the jib extended. The controller 52 automatically controls the upper work mode switch 71 to prevent the erroneous setting of the jib mode when the jib 7 is stored.
Therefore, since the fall accident of the jib 7 can be reliably prevented, the safety of the crane operation is improved, and the checking operation is not required, and the fatigue of the operator can be greatly reduced.

In the safety device for a mobile crane according to the second invention of the present invention, in the first invention, in each work mode selected by the work mode switch 71, the controller 52 controls the lock pin insertion detector 70 and the jib storage completion. A controller 52 is provided for warning when at least one of the detection signals from the detectors 33b and 33c is not input, by turning on an alarm lamp, issuing an alarm buzzer, or displaying characters on a monitor panel. It is characterized by having.

According to the second invention, the controller 52 includes the lock pin insertion detector 70 and the jib storage completion detector 3
When neither of the detection signals from 3b and 33c is input, an alarm lamp is turned on, an alarm buzzer is sounded, a warning is displayed by at least one of characters displayed on a monitor panel, or a boom 3 is extended. Automatically disables the operating valve for crane operation. Therefore, accidents such as the jib 7 dropping from the boom 3 can be prevented by performing crane operations such as extending the boom 3 carelessly in a state where the jib 7 is not completely stored in the boom 3, and the safety is improved. Can be greatly improved.

The safety device for a mobile crane according to the third invention of the present invention is the safety device according to the first invention, wherein a selection switch for selecting the traveling operation of the mobile crane and the operation of the work machine is installed, and the selection switch is driven. If the detection signal of the jib storage completion detectors 33b and 33c is not input when the operation is selected, the controller 52 warns the danger of the jib 7 falling during traveling by an alarm lamp, an alarm buzzer, a message output, or the like. It is characterized by having.

According to the third invention, when the controller 52 does not input the detection signals from the jib storage completion detectors 33b and 33c, the alarm lamp is turned on, the alarm buzzer is sounded, or the display is made on the monitor panel. The danger of the jib 7 dropping from the boom 3 is warned by, for example. Therefore, when the jib 7 is not completely stored in the boom 3 and the mobile crane runs carelessly,
Can be prevented from falling down from boom 3,
Safety can be greatly improved.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.
This will be described with reference to FIG. FIG. 1 is an overall side view of a mobile crane according to the present invention, and shows a stored state of a jib 7. In FIG. 1, the same members as those of the above-described conventional technology are denoted by the same reference numerals, and the description thereof will be omitted. The jib 7 is stored on the left side (or right side) of the boom 3 mounted on the vehicle body 1 so as to be able to undulate. The jib 7 includes a jib bracket 11 on the proximal end side and a jib body 12 on the distal end side. The jib bracket 11 and the jib body 12 are connected by a horizontal pin 13 so as to be able to move up and down, and can be raised and lowered around the pin 13 by a tilt cylinder 14.

The jib body 12 is secured by a locking means 20 as shown in detail in FIGS. 3, 5 and 7 and a fixing means 30 as shown in FIGS. 3, 5 and 8 to 12 in detail.
It is fixed to the left side surface of the base boom 4. An idler sheave 123 is provided on the upper surface of the distal end of the jib body 12, and a jib sheave 124 is provided at the distal end. The left and right sides of the base end of the jib bracket 11 are shown in FIGS.
As shown in detail in FIG. 1, left and right brackets 15 and 15 for connecting to the boom 3 and a right bracket 1
6 and 16 (the left and right sides are determined from the base end of the boom 3 toward the distal end. The same applies hereinafter). Lock cylinders 17, 18 are provided for inserting the 19b. Further, a top sheave (hereinafter, referred to as a single top) 125 is provided at a distal end of the top boom 6, and a single top 12 is provided.
5 is an auxiliary hook 1 provided at the tip of the auxiliary rope 121 via
22 are provided.

FIG. 2 is a plan view of the tip of the top boom 6 and the connecting portion of the jib bracket 11 when the jib 7 is stored. A turning cylinder 63 is provided on the upper part of the jib bracket 11.
The tube side is rotatably attached to the upper surface of the jib bracket 11, and the rod side is rotatably attached to the center of the second link 65. One end of the second link 65 is rotatably attached to the upper surface of the jib bracket 11, and the other end is rotatably connected to one end of the first link 64. The other end of the first link 64 is rotatably connected to one end of a third link 66, and the other end of the third link 66 is a boss 131 of a lock pin 19a (hereinafter referred to as "left pin 19a"), which will be described later. Are rotatably connected.

At the top and bottom of the left end of the top boom 6,
A left bracket 61 for connecting the jib 7 is provided.
The upper and lower left brackets 61 are provided with holes 61a for connecting the left bracket 15 of the jib 7 respectively. The upper left bracket 61 is further provided with a connection hole 61b into which a pin 67 of a connection portion between the first link 64 and the third link 66 is inserted. A right bracket 62 for connecting the jib 7 is provided above and below the right side of the tip end of the top boom 6, and a hole 62 a for connecting is provided in each of the upper and lower right brackets 62. Further, a first stopper 39 is fixed to the upper surface of the upper left bracket 61 over the hole 61a, and similarly, the first stopper 39 is secured to the lower surface of the lower bracket 61 below the hole 61a. It is fixed. A second stopper 42 b is provided on the left side surface of the top boom 6 so as to protrude toward the jib 7.

On the upper and lower sides of the base end of the jib bracket 11 on the boom side, left pins 19 for connecting to the top boom 6 are provided.
A left bracket 15 having a hole 15a into which a is inserted is provided, and lock pins 19b are provided on the upper and lower sides opposite to the boom side.
There is provided a right bracket 16 having a hole 16a into which (referred to as "right pin 19b") is inserted. Further, a boss 131 is provided on the upper surface of the upper bracket 15 and in the hole 15a, and the hole 15a penetrates the boss 131. Similarly, the lower surface of the bracket 15 and the boss 13 through which the hole 15a passes
1 is provided. A second stopper 42a is provided on the boom side surface of the jib bracket 11 so as to protrude toward the top boom 6 side. When connecting the jib, the upper and lower bosses 131 are connected to the upper and lower brackets 61 on the top boom 6 side.
Is pressed against the first stopper 39, and the second stopper 42a is brought into contact with the second stopper 42b on the top boom 6 side, so that the positions of the hole 15a and the hole 61a coincide. The second stopper 42a and the second stopper 42b may be either one.

FIG. 3 is a plan view of the center of the base boom 4 and the jib body 12 and the tip side thereof. At a substantially central portion of the jib body 12, a locking means 20 between the jib 7 and the base boom 4 as shown in detail in FIG. Also, a jib 7 as shown in detail in FIGS.
And a fixing means 30 for fixing the boom 4 to the base boom 4.

The details of the locking means 20 will be described with reference to FIG. 6, which is a sectional view taken along line XX of FIG. 3, and FIG. 7, which is a sectional view taken along line YY of FIG. Locking pins 21 projecting in the longitudinal direction of the boom 3 are provided above and below the side surface of the jib body 12 on the boom 3 side. The upper and lower locking pins 21 are respectively inserted and locked into locking holes 22a of a locking bracket 22 provided on the base boom 4 side. A hole 22b in the longitudinal direction of the boom 3 is provided at a lower portion of the locking bracket 22, and a pin 23 penetrates the hole 22b. Vertical holes are provided at both ends in the longitudinal direction of the pin 23, and a screw 24 passes through both holes. A nut 24a is inserted substantially at the center of both screws 24 and below the pin 23, and the upper and lower portions of the screw 24 are supported by the lower portion of the side surface of the base boom 4. Thus, the locking bracket 22 is supported by the nuts 24a via the pins 23. And nut 24
By adjusting the position a along the direction of the screw 24, the vertical position of the boom 3 of the locking bracket 22 can be adjusted.

A bracket 25 is provided on the upper side surface of the boom 3 and above the pin 23, and a pair of screws 26 are provided on the upper surface of the bracket 25 to face each other. Both screws 26 face in a direction perpendicular to the side surface of the boom 3 and their tips face each other. A nut 26a is inserted into each of the screws 26. And the upper part of the locking bracket 22 has both screws 2
6 is supported in a state of being sandwiched between the tip portions. Thus, by adjusting the position of the nut 26a,
The inclination of the locking bracket 22 around the pin 23 can be adjusted.

A support plate 28 extending downward is attached to the tip of the bracket 25, and a jib storage detector 29 is attached to a lower portion of the support plate 28. Jib storage detector 29
Indicates that the jib 7 has been retracted, that is, the locking pin 21
Is completely inserted into the hole 22a of the locking bracket 22. In the present embodiment, an example is shown in which a proximity switch is used as one of the jib storage detectors 29, and a detection plate 29a is attached to the jib body 12 for detecting the proximity switch. Although the proximity switch is used as the jib storage detector 29, the invention is not limited to this. For example, a limit switch may be used.

FIG. 8 is a detailed plan view showing a first embodiment of the fixing means 30 when the jib 7 is stored in the boom 3, and FIG.
FIG. 9 is a side view of FIG. At the lower side of the base boom 4, a bracket 34 protruding to the side is provided.
Is supported and fixed above the bracket 34 in the retracted state. A bracket 31 having a hole 31a for fixing the jib 7 is fixed to the side surface of the bracket 34 and to the base end side of the jib 7, and the side surface of the bracket 34 and the distal end portion of the jib 7. Jib 7 on the side
A bracket 35 having a guide hole 35a is attached. The position of the guide hole 35a is determined by the fixing hole 3a.
It is provided closer to the jib 7 than the position 1a.

A bracket 32 is provided on the side surface of the jib body 12 so as to protrude to the side of the boom 3, and the bracket 32 is provided with a hole 32 a for fixing the jib 7. A bracket 38 is provided on the side surface of the jib main body 12 and also protrudes to the side of the boom 3 side.
A pin 38a is provided at an upper portion of a substantially central portion of the bracket 34. A bracket 36 is provided on a side surface on the jib tip side of the bracket 38. When storing Jib 7,
The position of the hole 31a of the bracket 31 and the position of the hole 32a of the bracket 32 match by contacting the end face of the bracket 38 on the boom 3 side with the pin 38a. At this time, the pins 3 are inserted into the holes 31a and 32a.
3 is inserted and fixed. In the retracted state, the jib storage pin 33a is inserted into the tip of the pin 33. A shock absorbing buffer member may be provided at the tip of the pin 38a that contacts the bracket 38, and the buffer member is made of rubber, a spring, or the like.

In FIG. 9, the lower end surface 36a of the bracket 36 has an inclination, and this inclination is
The height of the lower end surface 36a with respect to the upper surface of the lower end is smoothly reduced from the front end portion to the base end portion. 8, the distal end of the bracket 36 has an inclined portion 36b from the distal end to the side surface 36c on the boom side, and the side surface 36c at the base end of the bracket 36 is substantially parallel to the side surface of the jib body 12. . Further, the lower end 36 of the bracket 36 is provided on the upper end of the side face on the jib base end side of the bracket 34.
The guide bar 37 a is fixed in parallel to the upper surface of the bracket 34. On the side of the bracket 34 near the base end of the jib 7, a detector 33b with a jib storage pin 33b for detecting that the jib storage pin 33 is inserted as shown in detail in FIG. I have.

FIG. 10 is a detailed plan view showing a second embodiment of the fixing means 30 when the jib 7 is stored in the boom 3, and the bracket 34 shown in FIG. A jib storage position detector 33c that detects that the jib 7 is at the storage position is provided instead of the installed detector 33b with a storage pin. Other configurations are the same as those in FIG.

FIG. 11 shows that when the jib 7 in the retracted state as shown in FIGS. 8 and 9 is extended toward the front of the top boom 6, the jib 7 is rotated around the locking means 20 as shown in FIG. FIG. 1 is a detailed plan view of the fixing means 30 when it is swung, and FIG.
2 is a side view of FIG. "Swinging out" the jib 7 means that the jib 7 is rotated around the locking pin 21 by moving the distal end of the jib 7 away from the boom 3 and the hole of the bracket 15 at the base end of the jib 7 is formed. This refers to the operation of aligning 15a with the hole 61a of the bracket 61 of the top boom 6.

The pin 33 is removed from the holes 31a and 32a, and the tip of the jib 7 is separated from the boom 3. The pin 33 is inserted into the hole 35 a of the bracket 35, and in this state, the side surface of the pin 33 contacts the side surface 36 c of the base end of the bracket 36 on the boom 3 side. by this,
The tip of the jib 7 is fixed by a pin 33 so as not to return to the boom 3 side. At this time, the boss 131 of the bracket 15 in FIG. 2 abuts on the first stopper of the top boom 6 to perform positioning in the front-rear direction, and the second stopper 42a on the jib 7 side becomes the second stopper 42b on the top boom 6 side. The hole 15a can be easily aligned with the hole 61a of the top boom 6 by being positioned in the left-right direction by contacting the hole.

FIG. 13 shows the jib 7 shown in FIG. 4 being swung clockwise by the cylinder 63 around the left and right pins 19a inserted in the holes 15a and 61a from the swinging state of the jib 7 to completely stretch the boom 3 forward. The right and left pins 19b are inserted and fixed in the holes 16a and 62a in the same manner as the left and right pins 19a.

FIG. 14 is a Z view in FIG. 2, and is a side view of the lock cylinder 17 and the connecting pin 19a between the upper and lower brackets 15. FIG. Lock cylinder 1
One end of a third link 66 is rotatably attached to the tube at the upper end of 7, and an upper left pin 19a is attached by a pin 19c. The axis of the left pin 19a coincides with the axis of the lock cylinder 17. The first link 6 is provided on the upper surface on the other end side of the third link 66.
A pin 67 for connecting the bracket 4 to the hole 61b of the bracket 61 of the top boom 6 is fixed. Further, a lower left pin 1 is provided on the rod side at the lower end of the lock cylinder 17.
9a is attached by a pin 19d.

The upper and lower brackets 15 each have a U-shape, and the upper and lower plates 15b, 15c and 1
Upper and lower brackets 61 each having a hole 15a provided on the top boom 6 side are sandwiched between 5d and 15e. The upper surface of the upper plate 15b and the hole 15
A portion is provided with a boss 131 through which the hole 15a passes. Similarly, on the lower surface of the lower plate 15e,
A boss 131 through which the hole 15a passes is provided in the hole 15a. Also, the third link 66 of the first link 64
Similarly, the connecting portion side is constituted by upper and lower plates 64a and 64b, and the hole 61b of the bracket 61 above the top boom 6 is sandwiched between the upper and lower plates 64a and 64b.

When the lock cylinder 17 is contracted to the shortest, the bracket 71 is provided to project from the base end of the jib bracket 11 toward the lock cylinder 17.
Of the lock cylinder 17 is sandwiched between the tube and the rod. In this state, the tip of the upper left pin 19a is hooked on the plate 15c of the upper bracket 15, and the tip of the pin 67 is hooked on the lower plate 64b of the first link 64. The tip of the lower left pin 19a is hooked on the plate 15d of the lower bracket 15.
Thereby, the lock cylinder 17, the first link 64,
The upper and lower left pins 19a and the pins 67 are connected to the jib bracket 11.
Not to come off.

A bracket 69 extending upward is attached to the rod of the lock cylinder 17.
A lock pin insertion detector 70 for detecting completion of the insertion of the upper and lower left pins 19a is attached to the upper end of 9. In the present embodiment, a proximity switch is employed as an example of the lock pin insertion detector 70, and the detection surface of the proximity switch faces downward in the direction of expansion and contraction of the lock cylinder 17.
A pole 68 extending downward is attached to the lower end of the tube of the lock cylinder 17, and a detection piece 68a of the proximity switch is attached to the lower end of the pole 68.

FIG. 15 is a view taken in the direction of the arrow A in FIG. 13, and is a view of the state in which the lock cylinder 17 is extended to connect the jib 7 and the top boom 6 as viewed from the side of the top boom 6. When the lock cylinder 17 is extended and the upper and lower left pins 19a are completely inserted into the holes 15a of the upper and lower brackets 15,
The proximity switch of the lock pin insertion detector 70 is
a is detected at a predetermined distance to operate. When the jib 7 is extended, the boss 131 of the bracket 15 is pressed against the upper and lower first stoppers 39 provided on the upper surface of the upper bracket 61 and the lower surface of the lower bracket 61. As a result, the positions of the hole 15a and the hole 61a match, and the left pin 19a can be inserted smoothly.

Although not shown, the bracket 15
Similarly, a lock cylinder 18 is provided between the upper and lower brackets 16, an upper right pin 19 b is provided at the upper end of the lock cylinder 18 on the tube side, and a lower pin 19 is provided at the lower end of the lock cylinder 18 on the rod side. The right pin 19b is attached. Similarly, when the lock cylinder 18 is contracted to the shortest position, the distal end of a bracket (corresponding to the bracket 71) provided to protrude from the base end of the jib bracket 11 toward the lock cylinder 18. The ends of the upper and lower right pins 19b are respectively connected to the cylinder side plates (plate 15c, plate 15c) of the U-shaped plates of the upper and lower brackets 16 respectively.
d). As a result, the lock cylinder 18 and the upper and lower right pins 19 b are connected to the jib bracket 11.
Not to come off.

FIG. 16 shows a front panel 4 for operating the extension / retraction of the jib of the mobile crane according to the present invention.
0a, and the front panel 40a is provided in the cab 9. The jib overhang / storage switch 41 for selecting the overhang / storage operation of the jib 7 is a seesaw type changeover switch. When the jib extension / retraction switch 41 is operated, the corresponding output contact shown in FIGS. 17 and 20 is turned on. Further, a left pin lock completion indicator 43 displayed when the bracket 61 on the left side of the top boom 6 and the bracket 15 of the jib 7 are completely connected by the left pin 19a, and the jib 7
When the lock pin 21 is retracted, the locking pin 21
A jib storage position indicator 67 is provided to indicate that the jib has been completely inserted into a. A jib storage completion indicator 44 is provided to display that the jib 7 is fixed to the boom 3 and detected by the jib storage completion detectors 33b and 33c.

The front panel 40a is provided with a mode changeover switch 45 for switching the operation mode. The lock cylinder 17 (left pin) is operated only by one operation of one operating lever 56a shown in FIG. ,
The rotation cylinder 63 and the lock cylinder 18 (right pin) can be operated. Therefore, it is possible to select which of these cylinders is to be used for the operation by the mode changeover switch 45. The operation direction of the cylinder is determined by the jib extension / retraction switch 4.
1 is switched.

A first embodiment of the electric control circuit and the hydraulic control circuit of the present invention shown in FIGS. 17 to 19 will be described. The electric control circuit shown in FIG. 17 includes a moment limiter controller 52 and other interlock means. The moment limiter controller 52 controls the extension of the boom 3 by judging whether or not the extension of the boom 3 is possible when the jib is extended, and is constituted by, for example, a microcomputer or the like. The moment limiter controller 52 is set in the preparation (jib extension / retraction) mode, jib mode, boom / boom mode by the upper operation mode switch 71 of the moment limiter display panel 40 as shown in FIG. 21 and FIG. Each upper work mode signal of the single top mode is input, and an ON / OFF command is output to the coil 46c of the jib automatic extension mode relay 46 based on the preparation (jib extension / retraction) mode signal. The output terminal of the lock pin insertion detector 70 is connected in parallel to the moment limiter controller 52 and the left pin lock completion indicator 43 via the cable drum 72. The left pin lock completion indicator 43 of the present embodiment is composed of a resistor and a light emitting diode (hereinafter, referred to as an LED), but may be a lamp or the like. Also,
The power terminal of the lock pin insertion detector 70 is connected to a battery power line (not shown) mounted on the vehicle via a power switch (not shown), a fuse F and the like, and a cable drum 72.

The output of the storage pin entry detector 33b turns on the jib storage completion indicator 44 and is output to the moment limiter controller 52. When the output of the storage pin input detector 33b and the output of the lock pin insertion detector 70 are simultaneously input or not input, the moment limiter controller 52 extends the switching operation valve 143 of the boom cylinder 141 shown in FIG. The solenoid 50a of the unload valve 50 connected to the side pilot operation unit is energized. Solenoid 50a
Since the unload valve 50 is unloaded by the energization of, the operation of the boom cylinder 141 on the boom extension side becomes impossible.

The common terminal of the a-contact output 46a of the jib automatic extension mode relay 46 is connected to the battery power supply line via the fuse F or the like as described above, and the a-contact output terminal is the common terminal of the jib extension / storage switch 41. c, power supply terminals of the jib storage position detector 29 and storage pin input detector 33b, and a contact outputs 47a of relays 47 and 48
1, 48a1 are connected in parallel to the common terminals. The output terminal a of the jib extension / retraction switch 41 when the extension is selected is connected to the coil 47c of the relay 47, and the output terminal b when the storage is selected is connected to the coil 48c of the relay 48 and the relay 51 via the cable drum 72. It is connected in parallel with the coil 51c. The output terminal of the jib storage position detector 29 is connected to a jib storage position indicator 67 and a relay 4 in parallel with the jib storage position indicator 67.
8, the coil 4 of the relay 49 via the contact output 48a2
9c. The output terminal of the storage pin input detector 33b is connected to a jib storage completion indicator 44 and to a moment limiter controller 52 in parallel with the jib storage completion indicator 44.

The other terminal side of the parallel circuit of the contact outputs 47a1 and 48a1 is connected to the common terminal d of the mode changeover switch 45.
And the jib side switching valve 73 via the cable drum 72
Is connected in parallel to the solenoid 73c. The output terminal a of the mode changeover switch 45 when the left pin is selected is a contact output 47a2 of the relay 47 and a contact output 4a of the relay 49.
9a1 and a cable drum 72
Is connected to the common terminal 51c1 of the relay 51 via the. Similarly, the output terminal b when the mode changeover switch 45 is selected for rotation and the output terminal c when the right pin is selected are connected to the other common terminals 51c2 and 51c3 of the relay 51 via the cable drum 72, respectively. .
The b-contact output 51b1 and the a-contact output 51a1 corresponding to the common terminal 51c1 are provided by a solenoid 53 of a left lock cylinder switching valve 53 for driving the lock cylinder 17, respectively.
d, 53e. Similarly, the b-contact output 51b2 and the a-contact output 51a2 corresponding to the common terminal 51c2 are connected to the solenoids 54d and 54e of the rotary cylinder switching valve 54 for driving the rotary cylinder 63, respectively, and correspond to the common terminal 51c3. B contact output 51
The b3 and a contact outputs 51a3 are connected to solenoids 55d and 55e of the right lock cylinder switching valve 55 that drives the lock cylinder 18, respectively.

The other end of the coil, indicator (LED), solenoid, detector (proximity switch), etc. of each relay is connected to the ground line of the battery. The cable drum 72 makes the cable connecting the boom tip side and the vehicle body side extendable and contractible.

In the hydraulic control circuit shown in FIG. 18, a pilot pipe from an operation valve 56 having an operation lever 56a for operating the tilt cylinder 14 is connected to a pilot operation section of a direction switching valve 57. The pressure oil discharged from the hydraulic pump 58 is guided to the P port of the direction switching valve 57, and the T port of the direction switching valve 57 is connected to the tank 59.
The A port of the direction switching valve 57 is connected to the pipeline 76, the reel 74a,
The port B is connected to the head side of the tilt cylinder 14 via a pipe 101 and a pilot operation check valve 78, and the B port is connected to a direction switching valve 73 via a pipe 77 and a reel 74b.

The directional control valve 73 supplies pressure oil to the tilt cylinder 1
It switches between supplying to the 4 side and supplying to the lock cylinders 17 and 18 and the rotating cylinder 63 for jib extension / retraction. The A port of the direction switching valve 73 is connected to the bottom side of the tilt cylinder 14 via a pipeline 102 and a counterbalance valve 79. The B port of the direction switching valve 73 is connected to the P port of the rotary cylinder switching valve 54 via the pipe 103, and the T port of the rotary cylinder switching valve 54 is connected to the right lock cylinder switching valve 55 via the pipe 104. The P port, the T port of the right lock cylinder switching valve 55 is connected to the P port of the left lock cylinder switching valve 53 via the line 105, and the T port of the left lock cylinder switching valve 53 is connected to the line 106 and the check valve 75. It is connected to the pipe line 101 via. At the neutral position b of each of the left lock cylinder switching valve 53, the rotary cylinder switching valve 54, and the right lock cylinder switching valve 55, the P port and the T port communicate with each other inside.

The A and B ports of the left lock cylinder switching valve 53 are connected to the bottom side and the head side of the lock cylinder 17 via a pipe 107 and a pipe 108, respectively. Further, the A and B ports of the right lock cylinder switching valve 55 are connected to the bottom side and the head side of the lock cylinder 18 via a pipe 109 and a pipe 110, respectively. Further, the A and B ports of the rotary cylinder switching valve 54 are connected to the bottom side and the head side of the rotary cylinder 63 via a pipe 111 and a pipe 112, respectively.

The boom operation hydraulic circuit shown in FIG. 19 includes a boom lever 14 for operating a boom cylinder 141.
The pilot pipe from the boom operation valve 142 having 2a is connected to the pilot operation part of the direction switching valve 143. The pressure oil discharged from the hydraulic pump 58 is supplied to the directional control valve 1
The directional control valve 143 is guided to the P port 43 and the T port of the directional control valve 143 is connected to the tank 59. A of the direction switching valve 143
The port is connected to the head side of the boom cylinder 141,
The B port is connected to the bottom side of the boom cylinder 141 via the counter balance valve 144.

An unload valve 50 operated by a solenoid 50a is connected to one pilot operation part of the direction switching valve 143. The pipeline 145 connecting the pilot pump 58a and the boom operation valve 142 is maintained at a constant pilot base pressure by the pressure control valve 146.

FIG. 20 is a diagram showing a second embodiment of the electric control circuit of the present invention. Components common to those in the first embodiment shown in FIG. 17 are denoted by the same reference numerals, and description thereof will be omitted. Only different portions will be described. When the insertion of the left pin 19a is completed, the lock pin insertion detector 70 detects the detection piece 68a, and the output of the lock pin insertion detector 70 turns on the left pin lock completion indicator 43, and the coil of the alarm switch 69 As it is energized, it becomes a B contact and the alarm buzzer 69a
And the alarm lamp 69b is not energized. On the other hand, storage pin 3
The output of the storage pin insertion detector 33b which detects the entry of 3 is also energized to the coil of the alarm switch 69, so that it becomes a B contact and is not energized to the alarm buzzer 69a and the alarm lamp 69b. Therefore, when the insertion of the left pin 19a is not completed and the storage pin 33 is not in the ON state, the coil of the alarm switch 69 is not energized, so that the contact becomes the A contact and the alarm buzzer 69a and the alarm lamp 69b are energized. Have been.

FIG. 21 is a view showing a moment limiter display panel 40 of the mobile crane according to the present invention. The moment limiter display panel 40 includes a jib operation, a boom / single top operation, and a preparation (jib extension / retraction). )
An upper operation mode switch 71 for selecting each upper operation mode of the operation is provided. FIG. 22 shows FIG.
It is an enlarged detail of a P part.

Next, the operation of the electric control circuit and the hydraulic control circuit shown in FIGS. 17 to 19 will be described. FIG.
At 7, the upper work mode switch 71 prepares the moment limiter controller 52 (jib extension / retraction).
When the mode signal is output, the coil 46c of the jib automatic extension mode relay 46 is energized from the moment limiter controller 52, and the a contact output 46a is turned on. (1) Preparation mode (operation of dibutyl cylinder) When the jib extension / retraction switch 41 on the front panel 40a in FIG. 15 is not operated on either the extension side or the storage side, the common terminal c of this switch is used. Is not connected to the output terminal a and the output terminal b. Therefore, relay 4
The coils 47c, 48c of Nos. 7, 48 are not energized, the a-contact outputs 47a1, 48a1 remain off, and the solenoid 73c of the direction switching valve 73 is not energized. Therefore, the direction switching valve 73 is at the position a, and the tilt lever 5
The operation of 6 causes the tilt cylinder 14 to expand and contract.

For example, when the tilt lever 56 is pulled forward, the direction switching valve 57 is switched to the position a, and the flow rate of the hydraulic oil discharged from the hydraulic pump 58 according to the tilt lever operation amount is changed to the pipeline 77 and the reel 74b. Via the direction switching valve 73
From the position a of the directional control valve 73,
2 and flows into the bottom side of the tilt cylinder 14 via the counter balance valve 79. The oil that has flowed out from the head side of the tilt cylinder 14 drains from the direction switching valve 57 to the tank 59 via the pilot operation check valve 78, the pipeline 101, the reel 74a, and the pipeline 76. by this,
Tilt cylinder 14 at a speed corresponding to the amount of tilt lever operation
Extends. When the tilt lever 56 is operated in the opposite direction, the direction switching valve 57 is switched to the position c, and the pressure oil discharged from the hydraulic pump 58 flows in the opposite direction, and the tilt cylinder 14 is moved at a speed corresponding to the tilt lever operation amount. Shrinks. At this time, the pressure oil in the pipeline 101 is prevented from flowing into the pipeline 106 by the check valve 75.

(2) Preparation mode (jib overhang operation) When the jib overhang / restore switch 41 is operated to the overhang side, the common terminal c of this switch is connected to the output terminal a. Therefore, the coil 47c of the relay 47 is energized, the a contact output 47a1 is turned on, and the solenoid 73c of the direction switching valve 73 is energized. Further, since the coil 51c of the relay 51 is not energized, each of the b-contact outputs 51b1,
51b2, 51b3 are common terminals 51c1, 51c2,
51c3. For this reason, the direction switching valve 73
Is switched to the position b, and the operation of the jib extension can be performed by operating the tilt lever 56.

(I) When the mode changeover switch 45 on the front panel 40a is switched to the "left pin" side, the common terminal d and the terminal a of the mode changeover switch 45 are connected.
Further, since the a-contact output 47a2 of the relay 47 is on, the solenoid 53d of the left lock cylinder switching valve 53
Is energized. As a result, the left lock cylinder switching valve 53 switches to the position a. At this time, tilt lever 5
6, the direction switching valve 57 is switched to the position "a", and the flow rate corresponding to the tilt lever operation amount of the pressure oil discharged from the hydraulic pump 58 is changed via the pipe 77 and the reel 74b to the direction switching valve 73. It is led to.

Further, from the position b of the direction switching valve 73, the line 103, the position b of the rotary cylinder switching valve 54, the line 10
4. Position b of right lock cylinder switching valve 55 and conduit 10
The liquid is guided to the position a of the left lock cylinder switching valve 53 through the valve 5 and flows into the bottom side of the lock cylinder 17 from the pipe 107. The oil flowing out from the head side of the lock cylinder 17 is supplied to the pipeline 108, the left lock cylinder switching valve 53, the pipeline 1
06, drain from the directional control valve 57 to the tank 59 via the check valve 75, the pipeline 101, the reel 74a and the pipeline 76. As a result, the lock cylinder 17 is extended at a speed corresponding to the tilt lever pull amount, and the upper and lower left pins 19a are inserted.

(Ii) When the mode changeover switch 45 is switched to the "rotation" side, the common terminal d and the terminal b of the mode changeover switch 45 are connected.
The fourth solenoid 54d is energized. As a result, the rotary cylinder switching valve 54 switches to the position a. At this time, when the tilt lever 56 is pulled forward, the hydraulic pump 58
Is discharged from the directional control valve 57 to the directional control valve 73 via the position a, and from the b position of the directional control valve 73 to the a position of the rotary cylinder switching valve 54 via the conduit 103. Then, it flows into the bottom side of the rotary cylinder 63 from the pipe line 111. The oil flowing out from the head side of the rotary cylinder 63 is supplied to the pipe 112, the rotary cylinder switching valve 54, the pipe 10
4. Drain from the directional control valve 57 to the tank 59 via the check valve 75, the pipe 101 and the pipe 76. As a result, the rotation cylinder 6 is rotated at a speed corresponding to the tilt lever pull amount.
3 is extended, and the jib 7 is pivoted forward and downward around the left and right pins 19a from the side of the boom 3.

(Iii) When the mode changeover switch 45 is switched to the "right pin" side, the common terminal d and the terminal c of the mode changeover switch 45 are connected, so that the solenoid 55d of the right lock cylinder changeover valve 55 is energized. You. Thereby, the right lock cylinder switching valve 55 switches to the position a. At this time, when the tilt lever 56 is pulled forward, similarly, the pressure oil discharged from the hydraulic pump 58 is guided to the direction switching valve 73 via the position a of the direction switching valve 57, and the b From the position, it is guided to the a position of the right lock cylinder switching valve 55 via the pipes 103 and 104 and flows from the pipe 109 to the bottom side of the lock cylinder 18. The oil flowing out from the head side of the lock cylinder 18 is
Pipe 110, right lock cylinder switching valve 55, pipe 10
5. Drain from the directional control valve 57 to the tank 59 via the check valve 75, the pipe 101 and the pipe 76. As a result, the lock cylinder 18 extends at a speed corresponding to the tilt lever pull amount, and the upper and lower right pins 19b are inserted.

When the tilt lever 56 is operated in the opposite direction at the time described above, the direction switching valve 57 is switched to the position c, and the pressure oil discharged from the hydraulic pump 58 is supplied to the pipeline 76,
It is led to the conduit 101. However, since the pressure oil in the pipeline 101 does not flow into the pipeline 106 by the check valve 75, the above-described cylinders are not reduced. Therefore, erroneous operation can be prevented.

(3) Preparation mode (jib storage operation) Next, when the jib extension / retraction switch 41 is operated to the storage side, the common terminal c of this switch is connected to the output terminal b. Therefore, the coil 48c of the relay 48 is energized, the contact a output 48a1 is turned on, and the directional control valve 7
The third solenoid 73c is energized. Further, since the coil 51c of the relay 51 is energized at the same time, the a contact outputs 51a1, 51a2, 51a3 are connected to the common terminal 51c1,
Connected to 51c2, 51c3. For this reason, the direction switching valve 73 switches to the position b, and the operation of the jib storage can be performed by operating the tilt lever 56.

(I) When the mode changeover switch 45 on the front panel 40a is switched to the “right pin” side, the common terminal d and the terminal c of the mode changeover switch 45 are connected,
The solenoid 55e of the right lock cylinder switching valve 55 is energized. As a result, the right lock cylinder switching valve 55 switches to the position c. At this time, when the operation lever 56 is pulled forward, similarly, the pressure oil discharged from the hydraulic pump 58 is guided to the direction switching valve 73 via the position a of the direction switching valve 57, and the position b of the direction switching valve 73 is similarly moved. From the pipe 103, the c position of the right lock cylinder switching valve 55, and the pipe 110 into the head side of the lock cylinder 18. Lock cylinder 1
The oil that has flowed out from the bottom side of line 8 is connected to line 109, right lock cylinder switching valve 55, line 105, check valve 75, line 1
01 and the directional control valve 57 to the tank 5
Drain to 9. Thus, the lock cylinder 18 contracts at a speed corresponding to the operation lever pull amount, and the upper and lower right pins 19b are pulled out.

(Ii) The mode switch 45 is turned.
Side, the solenoid 54e of the rotary cylinder switching valve 54 is energized. As a result, the rotary cylinder switching valve 54 switches to the position c. At this time, when the operating lever 56 is pulled forward, the pressure oil discharged from the hydraulic pump 58 is moved to the position a of the direction switching valve 57 and the position b of the direction switching valve 73.
Position, c of the rotary cylinder switching valve 54 via the conduit 103
It is guided to the position, and flows into the head side of the rotary cylinder 63 from the conduit 112. The oil flowing out from the bottom side of the rotary cylinder 63 drains from the direction switching valve 57 to the tank 59 via the pipe 111, the check valve 75, and the pipe 76. As a result, the rotary cylinder 63 contracts at a speed corresponding to the operation lever pull amount, and the jib 7 rotates around the upper and lower left pins 19a from the front of the boom 3 to the side.

(Iii) When the mode switch 45 is switched to the “left pin” side, the common terminal d and the terminal a of the mode switch 45 are connected. At this time, relay 4
Since the contact output 47a2 of the relay 7 is off, the relay 4
Whether the solenoid 53e of the left lock cylinder switching valve 53 is energized is determined by the on / off of the a contact output 49a1 of No. 9. That is, when the proximity switch as an example of the jib storage detector 29 detects the detection plate 29a, the output of the jib storage detector 29 turns on the coil 49c of the relay 49 via the a contact output 48a2, and only at this time. , The left lock cylinder switching valve 53 is turned on by turning on the contact output 49a1.
Is energized. Thereby, the left lock cylinder switching valve 53 switches to the position c.

Here, when the operation lever 56 is pulled forward,
The directional control valve 57 switches to the position a, and the hydraulic pump 58
From the pipe 77, the b-position of the direction switching valve 73, the pipe 103, the pipe 105, the c-position of the left lock cylinder switching valve 53, and the pipe 108 flow into the head side of the lock cylinder 17 from the pipe 108. . The oil flowing out from the bottom side of the lock cylinder 17 is supplied to the pipe 107, the check valve 75, and the pipe 76.
Through the directional control valve 57 to the tank 59. As a result, the lock cylinder 17 contracts at a speed corresponding to the operation lever pull amount, and the upper and lower left pins 19a are pulled out.

In FIG. 17, when a jib mode or a boom / single top mode signal is output from the upper work mode switch 71 to the moment limiter controller 52, the momentary limiter controller and the jib automatic extension mode relay 4 are output from the moment limiter controller.
6 is not energized, so that the a contact output 46
a turns off. At this time, normal jib work or boom / single top work becomes possible.

The procedure of the preparation (jib extension / storage) work will be described. (1) Preparation (jib overhang / retraction) work (i) Jib overhang work procedure 1) The operator pulls out the pin 33 of the fixing means 30 of the jib 7,
After the tip of the jib 7 is swung outward around the locking pin 21, the pin 33 is inserted into the guide hole 35a of the bracket 35 to prevent the jib 7 from swinging back. Accordingly, the left side surface of the top boom 6 is placed between the upper and lower plates 15b and 15c of the upper and lower brackets 15 at the base end of the jib 7 and between the upper and lower plates 15d and 15e. The upper and lower brackets 61 are sandwiched between the holes 15a and the holes 6 of each other.
1a is matched. The upper and lower plates 64 of the first link 64
a, 64b between the bracket 61 and the pin 67
And the hole 61b of the bracket 61 are matched.

2) Set the jib extension / retraction switch 41 of the operation panel in the cab 9 to the “extension” side, and set the mode changeover switch 4
5 is switched to the “left pin” side. In this state, the operation lever 56 is pulled. As described above, the lock cylinder 17 extends, and the upper and lower left pins 19 a are inserted into the holes 15 a of the upper and lower brackets 15 and the 61 a of the bracket 61. At the same time, the pin 67 of the third link 66 is
4 and the hole 61b of the upper bracket 61. 3) Wait until the insertion of the upper and lower left pins 19a is completed. When the insertion of the left pin 19a is completed, the lock pin insertion detector 7
0, the proximity switch detects the detection piece 68a,
The output of the lock pin insertion detector 70 turns on the left pin lock completion display 43. At the same time, the detection signal is input to the moment limiter controller 52.

4) After confirming that the above-mentioned left pin lock completion indicator 43 is lit, the operator turns off the "extension" of the jib extension / retraction switch 41 (this sets the jib mode). . Further, after operating the boom raising / lowering lever (not shown) to raise the boom by a predetermined angle, the user operates the boom extension / retraction lever (not shown) to extend the boom to a predetermined length. At this time, the moment limiter controller 52
Is designed to extend the boom 3 only when the detection signal of the lock pin insertion detector 70 is input. Therefore, since the boom 3 does not extend without the insertion of the left pin 19a being completed, a fall accident of the jib 7 can be prevented, and work safety can be improved. 5) The jib 7 is gradually lowered by the operation lever 56 while raising the boom 3 further. When the boom angle becomes a predetermined angle and the jib 7 becomes vertical, the auxiliary hoisting rope 121 is loosened and the auxiliary hook 122 is laid on the ground. Supplementary rope 121
Through the idler sheave 123 and the jib sheave 124 at the tip of the jib 7, the auxiliary rope 121 is slightly wound up to lift the auxiliary hook 122 from the ground, and the operation lever 56 maximizes the jib 7 (substantially with respect to the boom 3). Right angle) Prone.

6) Set the jib extension / storage switch 41 to "extension".
Side, the mode changeover switch 45 is switched to the “rotation” side, and the operation lever 56 is pulled in this state. As aforementioned,
The rotation cylinder 63 extends, and the jib 7 rotates forward of the boom 3. FIG. 13 shows a state in which the rotating cylinder 63 is extended and the jib 7 is rotated forward of the boom 3 and extended. 7) Switch the mode changeover switch 45 to the “right pin” side,
Pull the operation lever 56. The lock cylinder 18 extends,
The right pin 19b is connected to the upper and lower brackets 16 and 62.
In the holes 16a and 62a. 8) The "extension" of the jib extension / retraction switch 41 is turned off (this results in a jib mode), and the jib 7 is raised by the operation lever 56, and the boom 3 is lowered to the maximum until it is substantially horizontal. 9) Thereafter, replacement of the auxiliary hoisting rope 121 is performed.

As described above, the insertion of the left pin 19a after the swing of the jib 7, the raising and extension of the boom 3, the downward and rotation of the jib 7, the insertion of the right pin 19b, the raising of the jib 7,
Since each operation such as prone boom 3 can be performed in the cab 9,
Safety during work is increased. Further, the operator is confirmed by the display that the insertion of the left pin 19a has been completed, and when the insertion of the left pin 19a has not been completed, the moment limiter controller 52 does not extend the boom 3. Accordingly, it is possible to prevent the jib 7 from dropping due to the extension of the boom 3 when the insertion is incomplete.

(Ii) Procedure for Jib Storage Work It is possible to perform the work procedure and operation at the time of overhang described above substantially in reverse. Here, when storing the jib,
The jib overhang / store switch 41 is set to "store". However,
There are some procedures that are different from those at the time of overhang, and only this procedure will be described below. Reverse the above procedure for storing the jib, and
Is turned laterally from the front of the boom 3 and the jib 7 is further raised to be substantially parallel to the boom 3. (Up to this point, the reverse procedure of the above 9) to 5) is performed.) Then, as a work corresponding to the procedure 4), the boom 3 is contracted and the locking pin 21 of the jib 7 is
2a. FIG. 11 shows a state in which the tip of the jib 7 is guided at this time. As the boom 3 shrinks, the jib 7 moves along the side surface of the boom 3 toward the base end of the boom 3. Bracket 3 on the side of the jib 7
The lower surface 36a of the end 6 contacts the bar 37 of the bracket 34 of the boom 3. When the jib 7 moves toward the base end of the boom 3, the lower end surface 36 a is guided by the bar 37, and the bracket 36 rides on the bracket 34.

The inclined portion 36 at the tip of the bracket 36
The bracket 36 moves while the b contacts the side surface of the pin 33, and finally the side surface 36 c of the bracket 36
The bracket 36 is guided in a state of contact with the side surface of the bracket 36. In this state, the positional relationship between the locking pin 21 and the hole 22a is adjusted so that the locking pin 21 of the jib 7 is just inserted into the hole 22a of the locking bracket 22. This can be performed by adjusting the nut 24a in the vertical direction and adjusting the nut 26a in the horizontal direction. (See FIGS. 6 and 7.) As a result, as the boom 3 is reduced, the lower end surface 36a and the inclined portion 36b of the bracket 36 of the jib 7 are guided by the bar 37 and the pin 33, respectively, and the locking pin 21 is smoothly engaged. Stop bracket 22
Into the hole 22a.

As a procedure corresponding to 3), the process waits until the locking pin 21 is completely inserted into the hole 22a of the locking bracket 22. When the insertion of the locking pin 21 into the hole 22a is completed, the jib storage position detector 29 detects the detection plate 29a, and the detection output of the jib storage position detector 29 outputs the coil 49 of the relay 49.
Power on c. Then, the contact 49a1 is connected to connect the left pin 19
The operation of a is enabled. As a procedure corresponding to 2), when the jib extension / retract switch 41 is set to the “retracted” side and the mode changeover switch 45 is set to the “left pin”, the lock cylinder 17 is reduced by pulling the operation lever 56 as described above. The left pin 19a can be pulled out. As a result, if the locking pin 21 is completely inserted into the hole 22a and the jib storage position is not detected, the left pin 19a cannot be pulled out and the jib 7 can be prevented from dropping, and work safety can be reduced. improves.

The operation of the second embodiment of the electric control circuit shown in FIG. 20 will be described. Components common to those in the first embodiment shown in FIG. 17 are denoted by the same reference numerals, and description thereof will be omitted. Only different portions will be described. When the insertion of the left pin 19a is completed, the lock pin insertion detector 70 detects the detection piece 68a, the output of the lock pin insertion detector 70 turns on the left pin lock completion indicator 43, and the alarm switch 69
And the alarm buzzer 69a and the alarm lamp 69b do not operate.

On the other hand, the output of the storage pin insertion detector 33b which detects the insertion of the jib storage pin 33 is also used for the alarm switch 69.
And the alarm buzzer 69a and the alarm lamp 69b do not operate. That is, when the left pin 19a has been locked and the storage pin 33 has been extended.
The alarm switch 69 is switched to the contact B at the time of storage to detect the entry of the alarm, so that the alarm buzzer 68a and the alarm lamp 68
Does not work with b. That is, when the lock of the left pin 19a is not completed and the insertion of the jib storage pin 33 is not detected, the alarm switch 69 is switched to the A contact.
The alarm buzzer 69a and the alarm lamp 69b are activated to notify that it is dangerous. That is, these two pins 19a,
It warns that both 33 are missing. In this case, the alarm buzzer 69a and the alarm lamp 69b indicate that it is dangerous even if the unload valve 50 having the solenoid 50a as in the first embodiment shown in FIG. 16 is not required.

Next, the control for detecting the working state of the mobile crane according to the present invention will be described with reference to the control flowchart of the safety device for the mobile crane shown in FIG. 23 and Table 1.

[0083]

[Table 1]

(1) Running When "running" is selected by a PTO switch (not shown) installed in the cab 9, step S1 in FIG.
To S2. (i) In step S2, when the jib storage position detector 33b shown in FIG. 11 detects that the storage pin 33 is inserted, the process proceeds from step S2 to S3, and normal traveling is performed. In this case, as shown by the detection item m in Table 1, the crane vehicle is in a normal state and does not warn with a buzzer. However, it is set such that crane work such as a boom is always impossible in a traveling state of a crane truck. (ii) In step S2, the jib storage position detector 33b
If it is not detected that the storage pin 33 is inserted, the process proceeds from step S2 to S4, and the vehicle can run. However, an alarm buzzer is issued at the time of driving, and it is determined that the storage pin 33 is not inserted. It is displayed on the moment limiter display panel 40 of FIG. In this case, there is a danger of the jib 7 dropping as shown in the detection item;

(2) During operation (jib mode, boom mode,
When "operation" is selected by a PTO switch (not shown) installed in the operator's cab 9 in step S1 in FIG.
To S5. (i) In step S5, if the left and right pins 19a, the jib storing pin 33, and the work mode switch 71 are normal, the process proceeds from step S5 to S6, and the jib work, boom / single top work shown in Table 1 and Each normal operation of the preparation (jib extension / storage) operation is performed. In this case, as shown in the detection items in Table 1, a, f, i, and j, the state of the crane vehicle is normal. Work becomes possible. However, in the detection term j, a warning is continuously given by a buzzer to perform a preparatory operation for the jib extension and storage, and a crane operation such as a boom is disabled.

(Ii) In step S5, the left and right pins 19
If a, the storage pin 33, and the work mode switch 71 are abnormal, the process proceeds from step S5 to S7. . If the selection of the work mode switch 71 is correct in step S7, the process proceeds from step S7 to S8. (a) If both the left and right pins 19a and the storage pin 33 are disconnected in step S8, the process proceeds from step S8 to S9, and FIG.
19 from the moment limiter controller 52 shown in FIG.
, The solenoid 50a of the unload valve 50 is energized, and the operation of the boom switching operation valve becomes impossible, so that the extension operation of the boom is stopped, an alarm buzzer is issued, and the moment limiter display panel 40 "Dangerous jib drop", "Confirmation jib left pin", or "Confirmation" as shown in the detection items in Table 1 on the display; d, h, l
Displays one of the “storage pins”. (b) If the left and right pins 19a and the storage pin 33 are in the same position in step S8, the process proceeds from step S8 to S10. Since such a phenomenon is not actually possible, it is a failure of the controller 52 or the like. In such a case, the detection term in Table 1; c,
As shown in g and k, the solenoid 50a of the unload valve 50 in FIG. 19 is energized to stop the boom operation, intermittently warn for 10 seconds with a buzzer, and an "error" code is displayed on the display.

[0087] If the selection of the work mode switch 71 is not correct in step S7, steps S7 to S
11 and the detection terms in Table 1;
One of “Confirmation work mode switch”, “Confirmation jib left pin” or “Confirmation storage pin” is displayed on the moment limiter display panel, and 1
Alarm intermittently for 0 seconds.

The following erroneous operations can be prevented by the control shown in Table 1, which is safe. (1) Prevent the jib from dropping due to forgetting to insert the pin while the jib is overhanging and storing (jib preparation mode), and to prevent damage due to forgetting to pull out. (2) Prevent the jib from falling due to forgetting to insert the pin when the jib is stored on the side of the boom. (3) Warning of work mode selection error, such as performing boom work with the jib extended forward of the boom. (4) Prevents jib from falling due to forgetting to insert jib pin during running.

In each of the above embodiments, the operation of extending the boom 3 has been described. In addition to the operation of extending the boom 3, the boom 3 is contracted, the boom 3 is raised and lowered, the jib 7 is raised and lowered, and the main winch is raised. It is also possible to control the work of the mobile crane 11 in total for lowering, raising and lowering the auxiliary winch, and turning left and right.

[Brief description of the drawings]

FIG. 1 is a side view of a mobile crane according to one embodiment of the present invention.

FIG. 2 is a plan view showing a connecting portion when the jib is stored in one embodiment of the present invention.

FIG. 3 is a plan view of the jib retracted state in one embodiment of the present invention.

FIG. 4 is a plan view showing a connecting portion when the jib is swung out according to the embodiment of the present invention.

FIG. 5 is a plan view showing a jib projecting state in one embodiment of the present invention.

FIG. 6 is a sectional view taken along line XX of FIG. 3;

FIG. 7 is a sectional view taken along line YY of FIG. 6;

8 is a detailed view of a portion P in FIG. 3, wherein (A) is an overall plan view of the jib fixing means, and (B) is a view taken in the direction of arrow V in (A).

FIG. 9 is a side view of FIG.

FIG. 10 is a plan view showing a second embodiment of the jib storage detecting means corresponding to FIG.

FIG. 11 is a plan view showing a state immediately before swinging of a Q portion in FIG. 5;

FIG. 12 is a side view of FIG. 11;

FIG. 13 is a plan view showing a jib overhang state in one embodiment of the present invention.

14 is a view as viewed in the direction of the arrow Z in FIG. 2;

FIG. 15 is a view as viewed from the direction indicated by the arrow A in FIG. 12;

FIG. 16 is a plan view showing a front panel according to one embodiment of the present invention.

FIG. 17 is a diagram showing an electric control circuit according to one embodiment of the present invention.

FIG. 18 is a diagram showing a hydraulic control circuit according to one embodiment of the present invention.

FIG. 19 is a diagram showing a hydraulic control circuit according to one embodiment of the present invention.

FIG. 20 is a diagram corresponding to FIG. 17, showing a second embodiment of the present invention.

FIG. 21 is a diagram showing a moment limiter display panel in one embodiment of the present invention.

FIG. 22 is a detailed view of an R part in FIG. 21;

FIG. 23 is a diagram showing a control flowchart of the safety device in one embodiment of the present invention.

FIG. 24 is an overall side view of a mobile crane explaining a conventional technique.

FIG. 25 is a plan view of the movable crane of the related art in the jib retracted state of the boom and the jib.

FIG. 26 is a detailed plan view of the boom and jib connecting portion of FIG. 23.

FIG. 27 is a side view of the boom and the jib connection portion of the conventional mobile crane when the jib overhang is completed.

FIG. 28 is a plan view of a movable crane of the related art in a jib swinging state of a boom and a jib.

FIG. 29 is a detailed plan view of the boom and jib connecting portion of FIG. 28.

FIG. 30 is a plan view of a prior art mobile crane during jib extension.

FIG. 31 is a plan view of a mobile crane of the related art in a state where a jib overhang is completed.

32 is a detailed cross-sectional view around a pin in FIG. 25, (A) is a cross-sectional view taken along AA, and (B) is a cross-sectional view taken along BB.

FIG. 33 is a control circuit diagram of a boom telescopic cylinder of a conventional mobile crane.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Body, 3 ... Boom, 4 ... Base boom, 6 ... Top boom, 7 ... Jib, 8 ... Upper swing body, 9 ... Driver's cab, 11 ...
Jib bracket, 12 ... jib body, 13, 23, 33,
38, 80, 83, 94, 96, 97, 98, 99 ... pins, 14 ... tilt cylinders, 15, 16, 25, 31,
32, 34, 35, 36, 38, 61, 62,..., Brackets 15a, 16a, 22a, 22b, 31a, 32
a, 35a, 61a, 61b, 62a, 95 ... hole, 1
7, 18: lock cylinder, 19a: left pin (lock pin in claims), 19b: right pin, 15b, 15c, 1
5d, 15e: plate, 20: locking means, 21: locking pin,
22: locking bracket, 24, 26: screw, 24a, 2
6a: nut, 28: support plate, 29: jib storage position detector, 29a: detection plate, 30: fixing means, 33: jib storage pin, 33a: pin retaining pin, 33b: detector with storage pin (claim) , Jib storage completion detector), 33c ... jib storage completion detector, 36a ... lower end surface, 36b ... inclined portion, 36c ... side surface, 37 ... bar, 39 ... first stopper,
40: Moment limiter display panel, 40a: Front panel, 41: Jib extension / retract switch, 42a, 4
2b: second stopper, 43: left pin lock completion indicator,
44: Jib storage completion indicator, 45: Mode changeover switch, 46, 47, 48, 49, 51: Relay, 50: Unload valve, 52: Moment limiter controller,
53: Left lock cylinder switching valve, 54: Rotating cylinder switching valve, 55: Right lock cylinder switching valve, 56a: Operating lever, 56: Operating valve, 57, 73: Directional switching valve, 58 ...
Hydraulic pump, 58a pilot pump, 59 ... tank,
63: rotating cylinder, 64: first link, 65: second link, 66: third link, 67: jib storage position indicator,
68 ... pole, 68a ... detection piece, 69 ... alarm switch,
69a: alarm buzzer, 69b: alarm lamp, 70: lock pin insertion detector, 71: upper working mode switch, 7
2. Cable drum, 74a, 74b ... reel, 75 ...
Check valve, 76, 77, 101, 102, 103, 10
4, 105, 106, 107, 108, 109, 11
0, 111, 112: pipeline, 78: pilot operated check valve, 79: counterbalance valve, 81, 82, 85, 8
7a, 87b: lug, 84: one, 89: switch box, 92, 93: link, 121: auxiliary rope, 12
2: supplementary hook, 123: idle sheave, 124: jib sheave, 125: single top, 131: boss, 14
DESCRIPTION OF SYMBOLS 1 ... Boom cylinder, 142 ... Boom operation valve, 142a
.. Boom lever, 143 direction switching valve, 144 counterbalance valve, 145 pipe line, 146 pressure control valve.

Claims (3)

[Claims] A telescopic boom (3) and this boom
The jib (7) supported and stored by the fixing means (30) on the side of (3), the bracket (15) and the boom of this jib (7)
(3) A lock pin (19a) which goes into and out of one of the left and right brackets (61) at the tip, and a lock inserted into the bracket (15) and the bracket (61) when the jib (7) is used. In the safety device of a mobile crane that extends the jib (7) stored on the side of the boom (3) around the pin (19a) and extends it in front of the boom (3), the lock pin (19a) Was inserted into the bracket (15), (61) and the lock pin insertion detector (70), which was inserted into the hole (31a) of the fixing means (30), and stored in the boom (3). Jib storage pin (33) to secure jib (7)
A jib storage completion detector (33b, 33c) for detecting that the jib storage pin (33) is inserted into the hole (31a) or that the jib (7) is at the jib storage position; Upper work to select one of the boom or single top mode at the storage position of 7), the jib mode at the overhang position of the jib (7), and the preparation mode for extending and storing the jib (7). Mode switch (7
1), these detectors (70, 33b, 33c), and a controller (52) that stops or warns the crane operation or a part of its operation depending on the status of the switch (71). Safety devices in mobile cranes. 2. The work mode switch according to claim 1,
In each work mode selected in (71), the controller 5
2 does not input the detection signals from the lock pin insertion detector (70) and the jib storage completion detector (33b, 33c), either turn on the alarm lamp, issue the alarm buzzer, or A safety device for a mobile crane, comprising: a controller (52) for giving a warning by at least one of displaying by text. 3. A jib storing completion detector (33b, 3b), wherein a selection switch for selecting a traveling operation and a work machine operation of the mobile crane is installed, and when the selection switch selects the traveling operation. 33c) A mobile crane characterized by comprising a controller (52) that warns of the danger of falling of the jib while driving by using an alarm lamp, an alarm buzzer, or a message output when the detection signal from the controller 33c) is not input. Safety devices in the.