JPS5972327A - Oil-pressure circuit for clamshell with expandible arm - Google Patents

Abstract

PURPOSE:To roll up a hose by operating an arm only by a method in which a circuit to shorten an arm having a clamshell bucket at its tip is branched, and an oil-pressure motor to roll up a hose and to operate the bucket is operated at the branched circuit. CONSTITUTION:When a switch valve 19 is switched from neutral position to right position by an operator and an expandible arm 2 is contracted, an oil- pressure cylinder 5 and he expandilbe arm 2 are contracted through a pipeline 20. In this case, working oil flows from a port P1 even into an oil-pressure motor 16 through a pipeline 24 with a check valve 23, the oil-pressue motor 16 turns in the direction of winding the hose, and the hoses 11 and 12 of the working cylinder 10 of a bucket 8 are rolled up, whereby preventing the loosening of the hoses. On the contrary, when the oil-pressure cylinder 5 and the expandible arm 2 extend, the oil-pressure motor 16 serves as a pump, oil is circulated in a close circuit of the pipeline 26 with an oil tank 27, the pipeline 28, the oil-pressure motor 16, the pipeline 24, and a relief valve 25, and the inertial rotation of the stoppage of the motor 16 is prevented by the valve 25.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes a telescoping arm in which a plurality of arms are telescopically combined and extended and contracted by a hydraulic cylinder,
A clamshell bucket is attached to the lower end of the tip arm of the telescoping arm, and the clamshell bucket is equipped with an opening/closing hydraulic cylinder.This invention relates to a hydraulic circuit for a clamshell with a telescoping arm.

This type of Kushimshiel is equipped with a hose reel that winds up and lets out a hose for supplying and discharging hydraulic oil to and from a hydraulic cylinder for opening and closing the clamshell bucket to prevent the hose from sagging, and a means for operating the hydraulic cylinder and the hose reel. were prepared separately for each. However, when the operator extends and retracts the telescoping arm, the operator must also take up and unwind the hose reel, which is a disadvantage in that the operation is troublesome.

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks, it is an object of the present invention to provide a hydraulic circuit configured to facilitate operation of a clamshell with a telescoping arm.

In order to achieve this object, the hydraulic circuit of the clamshell with a telescoping arm of the present invention has a hose for supplying and discharging hydraulic oil to and from the hydraulic cylinder for opening and closing the clamshell packet. A hose reel with a hydraulic motor that is fixed to the packet frame and that winds up and lets out the hose is attached to the upper part of the base end arm of the telescoping arm, and the switching pulp for the telescoping arm and the hydraulic pressure for the telescoping arm are connected to each other.
A pipe line between the cylinder and the rod chamber is connected to a port that serves as a hydraulic oil inlet when the hose of the hydraulic motor is wound up, through a pipe line having a check valve, and the hose is connected to the hydraulic arm when the hydraulic arm is extended. When tension is applied, the hydraulic motor operates as a hydraulic pump, and conversely, when the telescopic arm 1 is contracted, the hydraulic oil introduced through the conduit having the check valve moves the hydraulic motor in the hose winding direction. An embodiment of the present invention will be described below with reference to the drawings.

2 is a boom attached to the clamshell main body (not shown) so that it can be raised and lowered freely; 2 is a telescopic arm that is rotatably attached to the tip of the boom 1 via a pin 3 by an arm cylinder 4; The arm shown is a two-stage type consisting of a proximal arm 2a and a distal arm 2b, but 3
It may also be constructed by combining steps of arms. Reference numeral 5 designates a hydraulic cylinder for extending and retracting the arm, the tube side of which is connected near the upper end of the proximal arm 2a with a pin 6, and the rod side of the cylinder connected to the vicinity of the lower end of the distal arm 2b with a pin 7, so that it can be extended into the telescopic arm. It is installed on. Reference numeral 8 denotes a clamshell packet rotatably attached to the lower end of the tip arm 2b, but still fixedly via an attachment frame 9 as shown in the figure, and within the attachment frame 9 is a hydraulic cylinder 10 for opening and closing the packet. Installation. Reference numeral 11.12 denotes a hose for supplying and discharging hydraulic oil to the bucket opening/closing hydraulic cylinder 10, and the hose near the lower end penetrates from the side near the lower end of the tip arm 2b and is fixed with a clamp 13.
Its upper part passes through the telescopic arm 2, passes through the hole 14 at the upper end of the proximal arm 2a so as to be movable above the base arm, is wound onto a hose reel 15 attached to the upper part of the proximal arm 2a, and is further attached to the boom 1. It is clamped along and connected to a hydraulic circuit (not shown) on the main body. 16 is a hydraulic motor for driving the hose reel 15. 17 is a hydraulic pump installed on the main body, 18 is a relief valve that sets the maximum discharge pressure, and 19 is a switching pulp for operating the hydraulic cylinder 5 for the telescopic arm, which is installed in the driver's cab. Reference numerals 20 and 21 denote pipes connecting the two secondary ports of the switching pulp 19 and the rod chamber and bottom chamber of the hydraulic cylinder 5, respectively, and the pipes on the rod chamber side, that is, the pipes to which pressure oil is supplied when the telescopic arm is contracted. A conduit 24 having a check valve 23 connects the passage 20 and the port P+ of the hose reel hydraulic motor 16 to which pressure oil is supplied at the time of hose winding 9. The line 24 is connected to an IJ line 26 with an IJ-F valve 25.
is connected to the oil tank 27 via the hydraulic motor 16
The other port P2 is connected to the oil tank 27 via a pipe line 28, thereby forming a closed circuit when the hydraulic motor 16 operates as a hydraulic pump.

In this circuit, when the operator switches the switching pulp 19 from the neutral position to the right position to retract the telescopic arm 2, hydraulic oil is supplied to the rod chamber of the hydraulic cylinder 5 via the pipe 20, and the hydraulic oil is supplied to the rod chamber of the hydraulic cylinder 5 and The telescopic arm 2 contracts. At this time, hydraulic oil flows into the hydraulic motor 16 from the port P through the conduit 24 having the check valve 23, and the hydraulic motor 16 rotates in the hose winding direction.
1.degree. 12 is wound onto the hose reel 15, thereby preventing the hose from sagging.

On the other hand, when the operator switches the switching pulp 19 to the left position, hydraulic oil is supplied to the bottom chamber of the hydraulic cylinder 5 through the conduit 21, and the hydraulic cylinder 5 and the telescopic arm 2 are extended. At this time, since the hoses 1], , 12 are fixed to the distal end arm 2b by the clamps 13, the hoses 11, 12 are tensed, causing the hose reel 15 and the hydraulic motor 16 to rotate in the hose reeling direction. At this time, the hydraulic motor 16 acts as a pump, and the hydraulic oil is transferred to the oil tank 27, the pipe line 28, the hydraulic motor 16, the pipe line 24,
It circulates in a closed circuit of a conduit 26 having a relief valve 25, and the relief valve 25 prevents rotation due to inertia when the hydraulic motor 16 is stopped.

In the above embodiment, the hoses 11 and 12 are passed through the telescopic arm 2, but they may also be located outside the telescopic arm 2, and the fixing portions of the hoses 11 and 12 are not provided at the end arm 2b. It may also be the frame 9 of the bucket 8 or the like.

As described above, according to the present invention, the hose reel that winds the hose that supplies and discharges hydraulic oil to and from the hydraulic cylinder for opening and closing the bucket is linked to the telescoping arm, so when the telescoping arm is extended and contracted, The operator only has to operate the switching valve for the telescopic arm, which greatly reduces the operator's workload and facilitates operation.

[Brief explanation of the drawing]

The drawing is a hydraulic circuit diagram showing an embodiment of the present invention. 0 2...Telescopic arm, 2a... Base end arm, 2b...
Tip arm, 5.10...Hydraulic cylinder, 8...Clamshell bucket, 11.12...Hose, 15...
・Hose reel, 16...Hydraulic motor, 19...Switching valve, 20, 21.24...Pipe line, 23...Check valve Patent applicant Hitachi Construction Machinery Co., Ltd. Agent Patent attorney Akimoto Masaru Actual agent Patent attorney Young 1) Masaru -

Claims (1)

[Claims] It is equipped with a telescoping arm in which a plurality of arms are combined into a telescopic pink and extended and retracted by a hydraulic cylinder, a clamshell bucket is attached to the lower end of the tip arm of the telescoping arm, and the clam shell bucket is equipped with a hydraulic cylinder for opening and closing. In the hydraulic circuit of the clamshell with a telescoping arm, a hose for supplying and discharging hydraulic oil to the hydraulic cylinder for opening and closing the clamshell bucket is fixed to the end of the distal arm of the telescoping arm, and the hose is connected to the packet frame. A hose reel connected to the hydraulic motor for winding and unwinding is installed at the upper part of the base end of the telescopic arm, and a pipe line between the switching valve for the telescopic arm and the rod chamber of the hydraulic cylinder for the telescopic arm is connected to the hydraulic motor. When the motor hose is wound up, it is connected to a boat that serves as a hydraulic oil inlet through a pipe line having a check valve, and when the oil field arm is extended, the hose is tensed to operate the hydraulic motor as a hydraulic pump, and vice versa. A clamshell with a telescoping arm, characterized in that, when the telescoping arm is contracted, the hydraulic motor is operated in the hose winding direction by hydraulic oil introduced through the conduit having the check valve. Hydraulic circuit.