JP2009203615A - Safety device of hydraulic excavator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device which maintains a held state even if an oil pressure switch for maintaining the holding of a material is turned off by a driver's false operation. <P>SOLUTION: A chuck 15 is opened/closed by a hydraulic cylinder 20. When the chuck 15 is opened, oil is pumped up from a tank 36 by a pump 37, and sent to the hydraulic cylinder 20 through an hose 32 for opening; and the hydraulic cylinder 20 is operated by its oil pressure. A stop valve 34 is installed in the hose 32. The closing operation of the stop valve 34 prevents the inflow of the oil even if it is forced to flow into the hose 32 so as to open the chuck 15, because a chuck opening/closing switch is accidentally pushed. The chuck 15 maintains a closed state, and the fall of the held material is prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a safety device for a hydraulic excavator, and more particularly to a safety device for a hydraulic excavator to which an attachment having a gripping function is attached.

  2. Description of the Related Art Conventionally, mobile trolleys such as hydraulic excavators (power shovels) are used for civil works and construction works by attaching various attachments to arms. Among the attachments, grapples and pile punching machines are used to grip, move, destroy, pile out, etc. building materials and objects to be disassembled. When using an attachment that grips such materials, if the hydraulic hose is cut while gripping the material and the gripping force decreases due to a decrease in hydraulic pressure, the material falls from the attachment. It is very dangerous.

In order to avoid such a risk, in Patent Document 1, the piston of the hydraulic cylinder device has a double structure, and a check valve device is provided in the middle of a pipe line connected to the piston so that oil from the check valve device can be removed. A tightening and holding device is disclosed in which the amount of leakage is small and the oil leaked from the check valve device is supplemented by oil accumulated in a cavity formed by sliding a small piston.
JP 56-119033 A

  The device disclosed in Patent Document 1 is a device that responds to an abnormal situation in which a hydraulic hose is cut due to some accident, but the driver is holding a hydraulic switch by holding the body by shaking the carriage. I couldn't cope with the situation where the oil pressure dropped because I hit the tool or the tool, or pushed it by mistake. The accident from the driver is more likely to occur than the hydraulic hose disconnection accident, and in this case too, it is very dangerous for people in the workplace because the material falls, but such an accident from the driver So far there has been no device to deal with.

  The present invention has been made in view of such points, and an object of the present invention is to provide a device that maintains a gripping state even if a hydraulic switch that holds the gripping of the material is turned off due to a malfunction of the driver. There is.

  In order to solve the above problems, a safety device for a hydraulic excavator according to the present invention is a safety device for a hydraulic excavator to which an attachment having a gripping function is attached, and the attachment is opened and closed by a hydraulic cylinder. The cylinder is connected to an opening hose to which oil is sent when the attachment is opened and a closing hose to which oil is sent when the attachment is closed, and the opening hose has a stop valve for preventing the oil flow. It was set as the structure provided. Here, the hydraulic excavator is a kind of construction machine, and can be used for various purposes by attaching and replacing various attachments at the tip of the arm. In many cases, a downward bucket is attached as an attachment and used as a backhoe. However, as an attachment, a breaker, a lifting magnet, a grapple, a cutter, a crusher, or the like may be attached. An attachment having a gripping function is a grapple, a pile punching machine, or the like, which grips construction materials or objects to be disassembled and moves, destroys, piles, or the like.

  With the above configuration, even if the hydraulic switch for holding the material grip is erroneously turned off, the attachment is kept closed if the oil flow is stopped by the stop valve.

  The stop valve is preferably provided in the operation chamber of the hydraulic excavator.

  The stop valve preferably includes a lock that holds the valve closed.

  The attachment can be a pile punching machine.

  Since the safety device of the present invention has a stop valve attached to the opening hose, if the flow of oil in the opening hose is stopped with the stop valve when the attachment is closed, the opening hose may become oiled due to malfunction. Even if oil is sent from the pump so that the oil flows, the oil is blocked by the stop valve, the attachment is not opened, and safety is ensured without the gripping material falling.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following drawings, components having substantially the same function are denoted by the same reference numerals for the sake of brevity.

(Embodiment 1)
FIG. 1 is a view showing a hydraulic excavator 1 to which a pile punching machine 2 is attached as an attachment. The excavator 1 has a boom 3 and an arm 4 attached to the tip of the boom 3, and a pile punching machine 2 is attached to the tip of the arm 4 via an extension arm 5.

  As shown in FIG. 2, the pile punching machine 2 includes a bracket 11 connected to the extension arm 5, a swivel frame 13 that is pivotably attached to the swivel unit 12 below the bracket 11 via a swivel unit 12, and a swivel frame 13. It is comprised by the vibration part 21 attached to the inner side through the rocking | fluctuation frame 14, and the chuck | zipper 15 attached under the vibration part 21. FIG. The vibration generating unit 21 generates vibration by rotating an eccentric weight in a box that is swingably attached to the swing frame 14 by a hydraulic motor 22.

  The chuck 15 includes a cylinder case 16, a fixed side chuck holder 17 attached to the cylinder case 16, an open / close side chuck holder 18, a chuck claw 19 attached so as to face both chuck holders 17, 18, and a cylinder case. 16 and a hydraulic cylinder 20 that opens and closes the open / close side chuck holder 18. Here, a hose that supplies oil to the hydraulic motor 22 and the hydraulic cylinder 20 is not shown.

  The pile punching machine 2 of this embodiment pinches the sheet pile 40 with the chuck | zipper 15 as shown in FIG. At this time, vibration is generated by the vibration generating unit 21, and the sheet pile 40 is driven into the ground by the vibration, the weight of the pile punching machine 2, and the pressing force of the hydraulic excavator 1. Or conversely, the sheet pile 40 driven into the ground is sandwiched between the chucks 15, and the sheet pile 40 is pulled up from the ground by pulling up the sheet pile 40 upward with the hydraulic excavator 1 while applying vibration by the exciter 21.

  During such driving or drawing operation or during preparation, when the chuck 15 sandwiching the sheet pile 40 opens or the gripping force decreases, the sheet pile 40 is dropped or the pile punching machine 2 turns in an unexpected direction. Or become very dangerous.

  The opening and closing of the chuck 15 is performed by the hydraulic cylinder 20 as described above. As shown in FIG. 3, oil is sent from a tank 36 through a solenoid valve 35 by a pump 37. When oil is sent to the hydraulic cylinder 20 from the opening hose 32 connected to the hydraulic cylinder 20, the link 33 moves the open / close side chuck holder 18 in the opening direction, and oil is sent to the hydraulic cylinder 20 from the closing hose 31. Conversely, the link 33 moves the open / close side chuck holder 18 in the closing direction. In the present embodiment, a stop valve 34 is provided on the opening hose 32 to securely close the opening hose 32 so that the chuck 15 is not opened carelessly.

  Next, the operation of the pile punching machine 2 of this embodiment will be described with reference to the driver seat of the excavator 1 shown in FIG.

  In order to pinch (chuck) the sheet pile 40 with the pile punching machine 2, first, the hydraulic excavator 1 is operated and the chuck 15 is held near the end of the sheet pile 40, and the fixed side chuck holder 17 is placed at the end of the sheet pile 40. Hit it. At this time, it is confirmed that the chuck 15 is open.

  The end portion of the sheet pile 40 is slid between the chuck holders 17 and 18, and the chuck opening / closing switch 53 is turned ON to the closed side. The stop valve 34 is kept open. Then, when the first axle 51 is stepped on, the pump 37 is operated, oil is sent to the closing hose 31 side through the solenoid valve 35, the hydraulic cylinder 20 is operated, the chuck 15 is closed, and the sheet pile 40 is sandwiched.

  Then, the stop valve 34 is closed and the lock 55 is pushed to lock. The stop valve 34 is a manual type and is opened when pulled to the near side and closed when pushed to the opposite side. The lock 55 is a push-in switch. Since the stop valve 34 is closed and locked in this way, the opening hose 32 is closed by the stop valve 34 even if the chuck opening / closing switch 53 is accidentally opened by hitting an arm or the like. Oil does not flow and the chuck 15 does not open. In order to open the chuck 15, it is first necessary to release the lock and manually move the stop valve 34 to the open side. Therefore, there is no possibility that the chuck 15 will be accidentally opened during the operation and the object being gripped will fall, and the surrounding people and the driver can work safely.

  Thereafter, the boom 3 and the arm 4 are operated to bring the sheet pile 40 to a predetermined position, and the second axle 52 is stepped on to feed oil to the hydraulic motor 22 to be vibrated and driven into the ground. Or you may pull out the piled sheet pile 40 by giving a vibration.

  When the driving operation is completed, the lock is released, the stop valve 15 is manually moved to the open side, and the chuck opening / closing switch 53 is turned ON to the open side. Then, the first axle 51 is stepped on to open the chuck 15 and release the sheet pile 40.

  In this embodiment, the stop valve 34 is manually closed after the sheet pile 40 is pinched by the chuck 15 and the lock is applied. Therefore, even if the driver accidentally touches the chuck opening / closing switch 53 and opens the chuck, The oil is stopped by the stop valve 34 and does not reach the hydraulic cylinder 20, and the chuck 15 does not open. Therefore, the safety of surrounding workers is ensured. Even if the stop valve 34 is accidentally hit by an arm or the like, the lock is applied, so the stop valve 34 is not opened and is very safe.

(Other embodiments)
The said embodiment is an illustration of this application, and this application is not limited to this example. The stop valve 34 may have any shape, structure, or the like as long as the flow of oil in the opening hose 32 can be reliably stopped. In order to avoid malfunction, the stop valve 34 is preferably not a switch but a valve having a structure in which a lever or a knob is manually operated. Further, the stop valve 34 may be installed anywhere. For example, it may be installed in the vicinity of the chuck 15 and the valve may be closed after the object to be gripped is chucked. However, it is preferable that the valve is installed in the driver's seat as in the first embodiment because work efficiency is improved.

  Further, the stop valve 34 may not be provided with the lock 55. In this case, the safety is slightly reduced, but it is rarely caused that the chuck opening / closing switch 53 malfunctions further to the open side after the stop valve 34 is erroneously operated to the open side. It is.

  Although the pile punching machine has been described in the above embodiment, the same safety device is useful when an attachment having a gripping function such as a grapple or fork is attached to the hydraulic excavator 1 for use.

  As described above, the safety device for a hydraulic excavator according to the present invention is useful as a safety device for pile punching machines, grapples and the like because it reliably prevents an attachment having a gripping function from being erroneously solved.

It is a schematic diagram of a hydraulic excavator equipped with a pile punching machine. (A) is a front view of a pile punching machine, (b) is a side view. It is a schematic diagram of the opening and closing mechanism of the chuck. It is a schematic diagram of the driver's seat of a hydraulic excavator.

Explanation of symbols

1 Hydraulic excavator 2 Pile punching machine 20 Hydraulic cylinder 32 Opening hose 34 Stop valve

Claims (4)

A safety device for a hydraulic excavator to which an attachment having a gripping function is attached,
The attachment is opened and closed by a hydraulic cylinder,
The hydraulic cylinder is connected to an opening hose to which oil is sent when opening the attachment and a closing hose to which oil is sent when closing the attachment.
A safety device for a hydraulic excavator, wherein the opening hose is provided with a stop valve for blocking the flow of the oil.   2. The excavator safety device according to claim 1, wherein the stop valve is provided in an operation chamber of the excavator.   The safety device for a hydraulic excavator according to claim 1 or 2, wherein the stop valve includes a lock.   The safety device for a hydraulic excavator according to any one of claims 1 to 3, wherein the attachment is a pile punching machine.

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