KR101142667B1 - Hydraulic shovel - Google Patents

Abstract

A hydraulic excavator 1 rotatably mounted to the traveling body 6, a boom 3 rotatably connected to the vehicle body 2, and an arm 4 rotatably connected to the boom 3. And a bucket 5 rotatably connected to the arm 4, a boom hydraulic cylinder 10 for driving the boom 3, an arm hydraulic cylinder 9 for driving the arm 4, and a bucket ( 5) Bucket hydraulic cylinder (8) for driving, boom control valve (15), arm control valve (35) and bucket for controlling the flow rate of hydraulic oil delivered to each hydraulic cylinder (8, 9, 10), respectively. The control valve 45 is provided, the boom 3 is formed in a hollow shape, and the bucket control valve 45 is disposed inside the boom 3.

Body, Hydraulic Shovel, Boom, Hydraulic Cylinder, Control Valve

Description

Hydraulic Shovel {HYDRAULIC SHOVEL}

This invention relates to the hydraulic excavator which drives the front attachment which consists of a boom, an arm, and a bucket with a hydraulic cylinder.

As a conventional hydraulic excavator, a control valve of a distributed arrangement type is provided in the front attachment, and the flow rate of the hydraulic oil delivered to each hydraulic cylinder is controlled by each control valve (Japanese Patent Application Laid-Open No. 2004). -293089, see Japanese Patent Application Laid-Open No. 2005-68718.

The hydraulic excavator disclosed in Japanese Patent Application Laid-Open No. 2004-293089 is arranged in the vicinity of each hydraulic cylinder in which each control valve drives the front attachment.

In the hydraulic excavator disclosed in Japanese Patent Application Laid-Open No. 2005-68718, each control valve is arranged side by side on the outside of the boom, respectively.

However, in such a conventional hydraulic excavator, since the control valve is provided in the front attachment, there is a problem that the weight balance of the front attachment is deteriorated by the weight of the control valve.

In addition, since the control valve is provided outside the front attachment, there is a possibility that the control valve, its pipes, or the like may come in contact with the obstacle and be damaged during operation.

The present invention has been made in view of the above problems, and an object thereof is to provide a hydraulic excavator capable of improving the weight balance of the front attachment and preventing damage to the control valve and the pipe.

The present invention relates to a hydraulic excavator rotatably mounted to a traveling body, a boom rotatably connected to the vehicle body, an arm rotatably connected to the boom, a bucket rotatably connected to the arm, and the boom. Hydraulic cylinder for boom to drive, Hydraulic cylinder for arms to drive the arm, Hydraulic cylinder for buckets to drive the bucket, Control valve for booms to control the flow rate of hydraulic oil delivered to each hydraulic cylinder, Control for arms And a valve and a control valve for the bucket, wherein the boom is formed in a hollow shape, and the control valve for the bucket is disposed inside the boom.

According to the present invention, the weight of the control valve for the bucket can be avoided from being caught by the arm, the weight balance of the front attachment is improved, and the operation of the front attachment is stabilized. In addition, the control valve for the bucket and the pipe connected to the bucket are prevented from coming in contact with the obstacle and being damaged.

BRIEF DESCRIPTION OF THE DRAWINGS It is a side view which shows the hydraulic excavator which concerns on embodiment of this invention.

2 is a hydraulic circuit for supplying and supplying hydraulic oil to a hydraulic cylinder for a bucket.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings.

As shown in FIG. 1, the hydraulic excavator (construction machine) 1 which concerns on embodiment of this invention is a vehicle body (revolving body) 2 provided in the upper part of the traveling body 6 which travels so that rotation is possible. .

The hydraulic excavator 1 includes a boom 3 rotatably connected to the vehicle body 2 via a boom support shaft 7, two hydraulic cylinders 10 for driving the boom 3, and a boom 3. An arm 4 rotatably connected to an end of the arm via an arm support shaft 38, one hydraulic cylinder 9 for driving the arm 4, and a bucket support shaft to the tip of the arm 4; A bucket 5 rotatably connected via 51 and one bucket hydraulic cylinder 8 for driving the bucket 5;

The hydraulic source unit 21 is mounted on the vehicle body 2. Each hydraulic cylinder 8 to 10 is stretched and operated by hydraulic oil guided from the hydraulic pressure source unit 21. When the hydraulic cylinders 8 to 10 are stretched and operated, each of the bucket 5, the arm 4, and the boom 3 rotates, and the excavation of the ground by the hydraulic excavator, the conveyance work of the earth and sand, etc. are performed.

The boom 3, the arm 4, and the bucket 5 form a multi-joint front attachment. In addition, the bucket 5 connected to the front-end | tip part of the arm 4 is not limited to carrying out excavation of the ground and conveyance of earth and sand, but may perform another operation.

The boom hydraulic cylinders (actuators) 10 installed in pairs are arranged with the boom 3 interposed therebetween. The hydraulic cylinders 10 for each boom are moved by the piston rod 12 with respect to the cylinder tube 11 by the hydraulic pressure which the internal piston (not shown) receives. The proximal end of each cylinder tube 11 is rotatably connected to the vehicle body 2 via the support shaft 13, and the distal end of each piston rod 12 is rotatable to the boom 3 via the support shaft 14. Is connected. The two hydraulic cylinders for booms 10 extend and contract in synchronism with each other by the operating hydraulic pressure supplied through the control valve 15 to drive the booms 3.

An arm hydraulic cylinder (actuator) 9 for driving the arm 4 is disposed at the rear portion of the boom 3. In the arm hydraulic cylinder 9, the piston rod 32 is moved relative to the cylinder tube 31 by the hydraulic pressure received by a piston (not shown) to expand and contract. The proximal end of the cylinder tube 31 is rotatably connected to the boom 3 via the support shaft 33, and the distal end of the piston rod 32 is rotatably connected to the arm 4 via the support shaft 34. do. The hydraulic cylinder 9 for the arm expands and contracts with the operating hydraulic pressure rapidly delivered through the control valve 35 to drive the arm 4.

The bucket hydraulic cylinder (actuator) 8 which drives the bucket 5 is arrange | positioned at the back part of the arm 4. As shown in FIG. The proximal end of the cylinder tube 41 is rotatably connected to the arm 4 via the support shaft 43, and the distal end of the piston rod 42 is rotatably connected to the bucket 5 via the support shaft 44. do.

2 is a hydraulic circuit for supplying and supplying hydraulic oil to the hydraulic cylinder 8 for a bucket.

The piston rod 42 is inserted into the cylinder tube 41 of the bucket hydraulic cylinder 8 so as to be retractable, and the piston 46 is connected to the proximal end of the piston rod 42. The piston 46 is interposed so as to be slidable along the inner circumference of the cylinder tube 41 and partitions the oil chamber 47 opposite the rod and the oil chamber 48 on the rod side in the cylinder tube 41. Hydraulic oil is supplied to the oil chamber 47 on the opposite side of the rod and the oil chamber 48 on the rod side through the control valve 45, and the hydraulic cylinder 8 for the bucket expands and contracts according to this hydraulic pressure. Drive.

The control valve 45 is composed of four electromagnetic valves V1 to V4 interposed in the bridge circuit. The electromagnetic valves V1 to V4 open and close by the output signal from the controller 30, and expand and operate the hydraulic cylinder 8.

To the discharge side of the hydraulic pump 22, a supply passage 25 through which the hydraulic oil supplied to the hydraulic cylinder 8 flows is connected, and the supply passage 25 is connected to branch passages 26 and 27 divided in two directions. . The branch passages 26 and 27 are again connected to the return passage 23 through which the hydraulic oil discharged from the hydraulic cylinder 8 flows. The return passage 23 is connected to the suction side of the hydraulic pump 22.

The branch passages 26 and 27 have a meter-in electromagnetic valve V1 for controlling the flow rate of the hydraulic oil supplied to the oil chamber 47 opposite the rod of the hydraulic cylinder 8, and the rod side oil chamber ( A metered electromagnetic valve V3 for controlling the flow rate of the hydraulic oil supplied to 48 is interposed in parallel.

The branch passages 26 and 27 also have a meter-out electromagnetic valve V2 for controlling the flow rate of the hydraulic oil discharged from the oil chamber 47 opposite the rod of the hydraulic cylinder 8, and the rod side oil. The meter-out electromagnetic valve V4 which controls the flow volume of the hydraulic fluid discharged | emitted from the chamber 48 is interposed in parallel.

Thus, the branch passage 26 is interposed with the metered electromagnetic valve V1 and the metered out electromagnetic valve V2 in series, and the branch passage 27 is provided with the metered electromagnetic valve V3 and the metered out electromagnetic valve. The valve V4 is interposed in series.

Between the quoting electromagnetic valve V1 and the meter-out electromagnetic valve V2 in the branch passage 26 are communicated with the oil chamber 47 opposite the rod via the first supply / discharge passage 28. The metered electromagnetic valve V3 in the branch passage 27 and the electromagnetic valve V4 for metering out are communicated with the rod side oil chamber 48 via the second supply / discharge passage 29.

The metered electromagnetic valve V1, the metered out electromagnetic valve V2, the metered electromagnetic valve V3 and the metered out electromagnetic valve V4 are electromagnetic control valves (flow control valves). Each electromagnetic valve V1-V4 is driven by the control current output from the controller 30, and an opening area is adjusted according to this control current. In this manner, the controller 30 individually adjusts the opening areas of the electromagnetic valves V1 to V4, and individually controls the flow rate of the hydraulic oil passing through the electromagnetic valves V1 to V4. The controller 30 receives signals from the pressure sensors 18 and 19 for detecting the pressures of the first supply and drain passages 28 and 29, respectively.

The boom control valve 15 and the arm control valve 35 also have the same configuration as the bucket control valve 45 and are controlled by the control current output from the controller 30. For this reason, in the hydraulic excavator 1, it becomes possible to disperse | distribute each control valve 15, 35, 45, respectively.

In the conventional hydraulic excavator, each control valve of the distributed arrangement type is provided in the vicinity of each hydraulic cylinder, and the length of the hydraulic pipe connecting the control valve and the hydraulic cylinder is shortened.

However, when the bucket control valve is installed in the vicinity of the bucket hydraulic cylinder, the weight balance of the front attachment consisting of the boom, the arm and the bucket is deteriorated by the weight of the bucket control valve. That is, the center of gravity of the hydraulic excavator 1 moves forward, and the hydraulic excavator 1 becomes unstable.

In addition, since the bucket control valve is moved together with the arm by providing the bucket control valve in the vicinity of the hydraulic cylinder for the bucket, there is a possibility that the bucket control valve, the pipe connected to it, and the like come into contact with the obstacle.

As a countermeasure, the present invention provides a distribution control type bucket control valve 45 inside the boom 3 to improve the weight balance of the front attachment, and to connect the bucket control valve 45 or the pipe to it. The main idea is to prevent damage.

In this embodiment, each control valve 15, 35, 45 of a distributed arrangement type is provided in the inside of the boom 3, respectively.

The boom 3 is formed in the hollow box shape by the steel plate, and each control valve 15, 35, 45 is accommodated and arrange | positioned in the space inside. Each control valve 15, 35, 45 is supported via a support member (not shown).

Each control valve 15, 35, 45 is arrange | positioned above the boom support shaft 7 which rotatably supports the boom 3 to the vehicle body 2. That is, the control valves 15, 35, 45 are disposed at a position higher than the boom support shaft 7, which is the rotation axis of the front attachment, regardless of the rotational position of the boom 3, and the control valves 15, 35, 45 is disposed so as to be located vertically above the boom support shaft 7 by the rotational position of the boom 3. This weakens the force in the direction in which the front attachment rotates. That is, the weight balance of the front attachment becomes good, and operation is stabilized.

Each control valve 15, 35, 45 is accommodated in the rear part of the boom 3, ie, the position close to the turning center axis O of the vehicle body 2. As shown in FIG. As a result, the free end side becomes lighter and the side closer to the vehicle body 2 becomes heavy, so that the front attachment has a good weight balance and stable operation. Further, since the center of gravity of the hydraulic excavator 1 is closer to the pivotal center axis O, the running stability of the hydraulic excavator 1 is improved. Moreover, the direction which extends from the boom support shaft 7 to the arm support shaft 38 in the boom 3 is made into the front of the boom 3, and the opposite direction is made into the rear of the boom 3.

As an arrangement | positioning of the bucket control valve 45, as shown in FIG. 1, the arrangement located in the perpendicular | vertical upper direction of the boom support shaft 7 near the neutral position of the hydraulic cylinder 10 for booms is preferable. By arranging the bucket control valve 45 in this manner, the weight balance of the front attachment is further improved.

Each control valve 15, 35, 45 is arranged side by side in the front-rear direction of the boom 3. The bucket control valve 45 is disposed between the boom control valve 15 and the arm control valve 35. The boom control valve 15 is arranged behind the bucket control valve 45, and the arm control valve 35 is arranged in front of the bucket control valve 45.

A part of each supply and drain passage 16, 17, 36, 37, 28, 29 extending from each control valve 15, 35, 45 to each hydraulic cylinder 10, 9, 8 is provided inside the boom 3. Are accepted.

The hydraulic excavator 1 is configured as described above, and switches the supply and drainage of the hydraulic oil to the hydraulic cylinders 10, 9, and 8 from the respective control valves 15, 35, and 45, respectively. ) Is telescopically driven and drives a multi-joint front attachment constituted by the boom (3), arm (4) and bucket (5), and grounded via bucket (5) connected to the distal end of arm (4). Excavation and conveyance work of earth and sand are carried out.

According to this embodiment above, the effect shown below is exhibited.

Since the bucket control valve 45 is disposed inside the boom 3 formed in the hollow box shape, the weight of the bucket control valve can be avoided from being caught by the arm 4. Therefore, the weight balance of the front attachment becomes good, and the operation of the front attachment is stabilized. In addition, it is possible to prevent the bucket control valve 45 and the pipe connected to the bucket from contacting and damaging the obstacle.

Moreover, since the bucket control valve 45 is arrange | positioned above the boom support shaft 7, the weight balance of a front attachment becomes favorable and operation is stabilized.

In addition, since the boom control valve 15 and the arm control valve 35 are arranged inside the boom 3 in parallel with the bucket control valve 45, the weight balance of the front attachment is further improved. Therefore, the operation of the front attachment is stabilized and damage to the control valves 45, 15, 35 and piping connected thereto is prevented.

In addition, since the bucket control valve 45 is constituted by the electromagnetic valves V1 to V4 that are individually opened and closed by the control current output from the controller 30, there are few restrictions on the arrangement, so that the inside of the boom 3 is limited. It becomes possible to arrange.

The present invention is not limited to the above-described embodiments, and it is obvious that various changes can be made within the scope of the technical idea.

INDUSTRIAL APPLICABILITY The present invention can be applied to a hydraulic excavator for carrying out excavation of ground and conveyance work of earth and sand.

Claims (4)

delete delete It is a hydraulic excavator 1 provided in the traveling body 6 so that the vehicle body 2 can turn. A boom 3 rotatably connected to the vehicle body 2, An arm 4 rotatably connected to the boom 3, A bucket 5 rotatably connected to the arm 4, A boom hydraulic cylinder 10 for driving the boom 3; An arm hydraulic cylinder 9 for driving the arm 4, A bucket hydraulic cylinder 8 for driving the bucket 5; A boom control valve 15, an arm control valve 35, and a bucket control valve 45 for respectively controlling the flow rates of the hydraulic oil delivered to the hydraulic cylinders 8, 9, and 10, respectively; A boom support shaft (7) rotatably supporting the boom (3) to the vehicle body (2), The boom 3 is formed in a hollow shape, Inside the boom 3, the control valve 15 for the boom and the control valve 35 for the arm are disposed in parallel with the control valve 45 for the bucket. The bucket control valve (45) is disposed above the boom support shaft (7), the hydraulic excavator. 4. The bucket hydraulic cylinder (8) according to claim 3, wherein the hydraulic cylinder (8) for the bucket has an oil chamber (47) opposite to the rod and a oil rod (48) on the opposite side, which is partitioned by a piston (46). The bucket control valve 45, A first metric electromagnetic valve (V1) for controlling the flow rate of the hydraulic oil supplied to the oil chamber 47 opposite the rod, A first meter-out electromagnetic valve V2 for controlling the flow rate of the hydraulic oil discharged from the oil chamber 47 opposite the rod; A second metric electromagnetic valve (V3) for controlling the flow rate of the hydraulic oil supplied to the rod side oil chamber (48), A second meter-out electromagnetic valve V4 for controlling the flow rate of the hydraulic oil discharged from the rod side oil chamber 48; A hydraulic excavator, characterized in that it comprises a controller (30) for individually controlling the flow rates of the hydraulic oil passing through the metered electromagnetic valves (V1, V3) and the metered out electromagnetic valves (V2, V4).

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