JP2008045365A - Working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To separate a counter weight 5 from a machine main body in such a way that an accumulator 10 provided for the counter weight 5 may be in a state left in the counter weight 5 in the case of separating the counter weight 5 when a hybrid type hydraulic excavator in which potential energy at the time when a boom is lowered is accumulated in the accumulator 10 and reused is transported and at other times. <P>SOLUTION: A mounting base 21A for mounting the accumulator 10 is provided with check valves 30 and 36 required for the installation of the accumulator 10 and preferable to be maintained together. By separating the check valves from piping on the side of the machine main body, the check valves are left together in the counter weight. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention belongs to the technical field of a hybrid work machine that can accumulate and reuse the potential energy of a working unit in an accumulator.

Generally, in a working machine such as a hydraulic excavator, a front working part for performing various operations such as excavation and loading is mounted on the front part of the machine body, and the balance between the weight of the front working part itself and the work load performed by the front working part. Some have counterweights at the rear of the aircraft. Such a counterweight is generally formed by filling a hollow outer shell made of a steel plate with a filler made of iron, cement, or the like.
By the way, in recent years, in a working machine such as a hydraulic excavator, from the viewpoint of environmental problems, a hybrid system has been developed in which the potential energy of the working unit is accumulated (accumulated) in an accumulator and can be reused. . However, when using such a type of work machine, it is necessary to secure a space for storing the accumulator.
Therefore, conventionally, a technique has been proposed in which an accumulator and other devices are accommodated in the internal space of the counterweight (see, for example, Patent Documents 1, 2, and 3).
JP 2004-116676 A JP 2003-328392 A JP 2001-40705 A

By the way, since work machines such as hydraulic excavators are not suitable for long-distance travel and high-speed travel, they are often transported by transport vehicles to the work site.In this case, considering legal regulations and ease of transport, etc. The counterweight may be removed from the aircraft for transport. In such a case, when the accumulator is stored in the counterweight as in the conventional case, the accumulator is connected to a pipe connected to the hydraulic device on the side of the machine body. As a result, the accumulator is connected to the counterweight. It is necessary to attach the accumulator to the counterweight again when it arrives at the site, which is cumbersome, cumbersome and inferior in workability.
In addition, when accumulators are installed, valves are required to control the supply and discharge of pressure oil to the accumulator and to control the discharge of pressure oil to the oil tank. However, since these valves are conventionally provided on the main body side, there is a problem that the workability is inferior, and there is a problem to be solved by the present invention.

The present invention has been created in view of the above-described circumstances and has been created for the purpose of solving these problems. The invention of claim 1 is directed to a counterweight provided in the body of the machine body with potential energy possessed by the working unit. In a working machine configured with an accumulator that accumulates pressure to recycle, an installation base is provided in a storage space formed in the counterweight, and the installation base includes , An input / output control valve for controlling input / output of pressure oil to / from the accumulator, a discharge control valve for controlling discharge of pressure oil to the oil tank, and an oil passage necessary for connecting the control valve and the accumulator. And a supply pipe to which pressure oil for accumulating the accumulator is supplied, and discharging the pressure oil from the accumulated accumulator The installation base is equipped with a drain pipe for draining oil and a drain pipe for draining oil to the oil tank, and these pipes are detachably connected via external pipes connected to the corresponding devices. Is a working machine characterized by
The invention according to claim 2 is the work machine according to claim 1, wherein an externally connected pipe provided on the installation base is provided with a stop valve that can be freely opened and closed.

According to the first aspect of the present invention, when the counterweight is removed from the main body for transportation or the like, the accumulator is installed on the counterweight side together with the control valve to be placed in the vicinity in order to improve the maintainability of the accumulator. In this way, the counterweight can be separated and the workability is improved.
According to the invention of claim 2, when the counterweight is separated, it is possible to prevent oil from leaking from the pipe for connecting the external pipe provided on the installation base.

  Next, embodiments of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a hydraulic excavator as an example of a work machine. The hydraulic excavator 1 includes a crawler-type lower traveling body 2, an upper revolving body 3 that is pivotably supported above the lower traveling body 2, The front working unit 4 is mounted on the front part of the upper swing body 3 and the rear part of the upper swing body 3 includes the weight of the front work unit 4 itself and the work load performed by the front work unit 4. A counterweight 5 is mounted for balancing.

  The front working unit 4 includes a boom 6 whose base end is supported by the upper swing body 3 so as to be swingable up and down, an arm 7 supported at the tip of the boom 6 so as to be swingable back and forth, and a tip of the arm 7 It is comprised from the bucket 8 etc. which are attached to a part. The potential energy of the front working unit 4 increases as the boom 6 is raised, but the potential energy is obtained by guiding oil discharged from the boom cylinder 9 to the accumulator 10 when the boom 6 is lowered. While being accumulated as hydraulic energy, the hydraulic energy accumulated in the accumulator 10 is configured to be supplied to the boom cylinder 9 when the boom 6 is raised, and thus the potential energy of the front working unit 4 is provided. Can be recovered and reused.

  In the present embodiment, three accumulators that are optimal for accumulating hydraulic energy are used as the accumulator 10, but these three accumulators 10 are provided inside the counterweight 5 as will be described later. Are stored in the left and right accumulator storage spaces 11A and 11B. The accumulator 10 is not limited to the bladder type but may be a piston type.

  The counterweight 5 is attached to the rear portion of the upper swing body 3 as described above. In order to move the counterweight 5 up and down so that the counterweight 5 can be easily attached and detached during transportation or the like. The weight moving device 12 is attached to the rear center portion of the rear surface portion of the upper swing body 3 so as to protrude rearward from the rear surface portion.

  The weight moving device 12 includes a hydraulic cylinder 13, a sprocket 14 that moves up and down based on the expansion and contraction operation of the hydraulic cylinder 13, and a chain 15 that is suspended around the sprocket 14. One end side is fixed to the rear surface part 3 a side of the upper swing body 3, while the other end side is detachably fixed to the central portion in the left-right direction of the counterweight 5. Then, with the other end of the chain 15 fixed to the counterweight 5, the hydraulic cylinder 13 is expanded and contracted to move the sprocket 14 up and down, so that the counterweight 5 suspended from the chain 15 is moved upward. It is comprised so that it can be moved up and down with respect to the turning body 3. FIG. The counterweight 5 is detachably fixed to the upper swing body 3 by fixing means such as a bolt (not shown), and the vertical movement of the counterweight 5 by the weight moving device 12 is fixed by the fixing means. It is performed in the state that is released.

  On the other hand, the counterweight 5 is filled with a filler 17 mainly composed of iron, water, cement, etc. in a hollow outer shell 16 made of a steel plate that forms the outer shell of the counterweight 5. In the central portion of the counterweight 5 in the left-right direction, a weight moving device storage space 18 for storing the weight moving device 12 protruding rearward from the rear surface portion of the upper swing body 3 is formed. Left and right accumulator storage spaces 11A and 11B in which the accumulator 10 is stored are formed on the left and right sides of the weight moving device storage space 18, respectively. The weight moving device storage space 18 and the left and right accumulator storage spaces 11A and 11B are open on the front side (side facing the rear surface of the upper swing body 3), while the left and right side surfaces and the back side are surrounded by the filler 17. Thus, the storage spaces 18, 11 </ b> A, and 11 </ b> B are separated by the filler 17. 20A and 20B are partition plates for partitioning the left and right accumulator storage spaces 11A and 11B from the filler 17, and these partition plates 20A and 20B are integrally fixed to the outer shell 16 by welding or the like. ing.

  In the left and right accumulator storage spaces 11A and 11B, three accumulators 10 are stored as described above. In the present embodiment, one accumulator 10 is stored in one accumulator storage space 11A and the other is stored in the other accumulator storage space 11A. In the accumulator storage space 11B, two accumulators 10 are stored in a state of being installed on installation bases (installation blocks) 21A and 21B, respectively. The accumulators 10 stored in the left and right accumulator storage spaces 11A are connected to each other via a hydraulic pipe (hydraulic hose) 22. The hydraulic pipe 22 is disposed through the hollow pipe 23. Yes. The accumulator 10 is connected to the hydraulic pipe 22 through an oil passage (described later) formed in the installation bases 21A and 21B, and the two accumulators 10 stored in the other accumulator storage space 11B are They are connected by an oil passage formed in the installation table 21B.

  Further, a recovery oil passage 24 is formed by branching from the head side oil passage 25 of the boom cylinder 9, and a recovery valve (recovery valve) 26 is disposed in the recovery oil passage 24. A downstream oil passage 26 a of the recovery valve 26 is connected to an accumulator oil passage 27 and a suction oil passage 29 of the boom pump 28. Further, the recovery oil passage 24 is provided with a check valve 45 that allows oil flow from the cylinder head side oil passage 25 to the accumulator oil passage 27 and the suction oil passage 29 but prevents reverse flow. . Thus, the oil discharged from the head side oil chamber 9 a of the boom cylinder 9 to the cylinder head side oil passage 24 can be supplied to the accumulator oil passage 27 and the suction oil passage 29 via the recovery oil passage 24. It can be done.

  The recovery valve 26 is an open / close valve in which the spool moves based on an operation signal output from a controller (not shown). When the operation signal is not input, the recovery valve 26 is positioned at a closed position N where the recovery oil passage 24 is closed. However, when the operation signal is input, the spool is moved to switch to the open position X where the recovery oil passage 24 is opened.

  The movement stroke of the spool of the recovery valve 26 is controlled to increase / decrease by the signal value of the operation signal of the controller, and the head side oil chamber of the boom cylinder 9 is controlled by the increase / decrease control of the movement stroke of the spool. The flow rate of oil flowing from 9 a to the accumulator oil passage 27 and the suction oil passage 29 via the recovery oil passage 24 is controlled.

  On the other hand, the accumulator oil passage 27 is an oil passage extending from the recovered oil passage 24 to the accumulator 10 via an accumulator check valve (corresponding to an input / output control valve for controlling input / output of pressure oil to / from the accumulator 10) 30. Thus, the maximum pressure in the accumulator oil passage 27 is limited by a relief valve 31 connected to the accumulator oil passage 27. In this embodiment, the accumulator 10 is a bladder type that is optimal for accumulating hydraulic energy, but is not limited thereto, and may be a piston type, for example.

  The accumulator check valve 30 includes a poppet valve 32 and an accumulator check valve electromagnetic switching valve 33 that switches from the OFF position N to the ON position X based on an ON signal output from the controller. The poppet valve 32 allows the flow of oil from the recovered oil passage 24 to the accumulator 10 regardless of whether the accumulator check valve electromagnetic switching valve 33 is in the OFF position N or the ON position X. The flow of oil from 10 to the suction oil passage 29 is blocked when the accumulator check valve electromagnetic switching valve 33 is located at the OFF position N and allowed only when it is located at the ON position X. Has been. Note that the flow of oil from the recovered oil passage 24 to the accumulator 10 is allowed regardless of whether the accumulator check valve electromagnetic switching valve 33 is in the OFF position N or the ON position X as described above, but the accumulator check valve When the electromagnetic switching valve 33 is in the ON position X, the pressure in the accumulator oil passage 27 does not act in the direction to close the valve passage of the poppet valve 32, so that the recovery oil passage 24 has almost no pressure loss. Oil can flow into the accumulator oil passage 27.

Further, 34 is a discharge oil passage that is branched from the suction oil passage 29 and reaches the oil tank 35, and a tank check valve 36 is disposed in the discharge oil passage 34.
The tank check valve (corresponding to a discharge control valve for controlling the discharge of pressure oil to the oil tank 35) 36 is changed from the OFF position N to the ON position X based on the poppet valve 37 and the ON signal output from the controller. A tank check valve electromagnetic switching valve 38 to be switched is used. The poppet valve 37 allows oil flow from the suction oil passage 29 to the oil tank 35 only when the tank check valve electromagnetic switching valve 38 is located at the ON position X, and is located at the OFF position N. It is designed to stop when you are. For example, when the excavator 1 is finished or maintained, the accumulator check valve electromagnetic switching valve 33 and the tank check valve electromagnetic switching valve 38 are both switched to the ON position X to accumulate pressure in the accumulator 10. The pressurized oil can be discharged to the oil tank 35. In FIG. 5, E is an engine, and 39 is an electromagnetic proportional switching control valve for expanding and contracting the boom cylinder 9.

  By the way, a valve assembly 40 including an accumulator check valve 30, a relief valve 31, and a tank check valve 36 is incorporated in an installation base 21A to which one accumulator 10 disposed in the storage space 11A of the counterweight 5 is attached. The above-mentioned piping necessary for connecting is formed. The installation base 21A includes an external pipe 41 for the recovery valve downstream side oil path 26a, an external pipe 42 for the discharge oil path 34, and an external pipe 43 for the suction oil path 29 respectively corresponding to the oil paths 26a, 34, 29 pipes can be detachably connected via male and female couplers 41a, 42a and 43a. The installation table 21A is provided with stop valves 26b, 29a, 34a for closing the recovery valve downstream oil passage 26a, the suction oil passage 29, and the discharge oil passage 34 so as to be freely opened and closed. The valves 26b, 29a, and 34a can be opened and closed simultaneously by operating the lever 44.

  In the embodiment of the present invention configured as described above, an accumulator 10 for accumulating pressure oil in the counterweight 5 and reusing it is provided on the installation bases 21A and 21B, and the one installation base 21A includes , An accumulator check valve 30 for controlling input / output of pressure oil to / from the accumulator 10, a tank check valve 36 for controlling discharge of the pressure oil to the oil tank 35, and an oil passage for connecting them. Thus, the maintenance of the accumulator 10 can be performed simultaneously with the maintenance of the check valves 30 and 36, and the maintainability is improved.

In addition, the accumulator 10 is provided with the check valves 30 and 36, and the external pipes 41, 42, and 43 are left on the counterweight 5 side together with the installation bases 21A and 21B provided with oil passages for connecting them. The counterweight 5 is removed from the fuselage main body by removing from the piping for the recovery valve downstream oil passage 26a formed on the installation base 21A side, the piping for the discharge oil passage 34, and the piping for the suction oil passage 29, respectively. It can be easily separated. As a result, when the excavator is transported, the accumulator 10 can be left on the counterweight 5 together with the installation paths 21A and 21B provided with the oil passages and the check valves 30 and 36, and on the counterweight side. The piping can be easily detached from the body side.
Moreover, when the pipes are separated, the stop valves 26b, 29a, and 34a are provided on the installation base 21A side, so that it is possible to prevent oil from leaking from the accumulator side when the pipes are separated.

It is a side view of a hydraulic excavator. It is a perspective view of the counterweight part which shows the state in which the accumulator was accommodated. It is a top view of the counterweight which shows the state in which the accumulator was accommodated. It is side surface sectional drawing of the counterweight which shows the state in which the accumulator was accommodated. It is a hydraulic circuit diagram which shows the piping state with respect to an accumulator.

Explanation of symbols

5 Counterweight 10 Accumulator 21A, 21B Installation stand 30 Accumulator check valve 36 Tank check valve

Claims (2)

In a work machine configured to include an accumulator that accumulates pressure to reuse the potential energy of the working unit on a counterweight provided in the machine body,
In installing an installation stand in the storage space formed in the counterweight, and installing an accumulator on the installation stand,
Necessary for connecting the input / output control valve for controlling the input / output of the pressure oil to the accumulator, the discharge control valve for controlling the discharge of the pressure oil to the oil tank, and the accumulator. And an oil passage
A supply pipe for supplying pressure oil for accumulating the accumulator, a discharge pipe for discharging the pressure oil from the accumulated accumulator, and an oil discharge pipe for discharging the oil to the oil tank. A work machine characterized in that these pipes are detachably connected to each other through external pipes connected to corresponding devices.   2. The work machine according to claim 1, wherein an externally connected pipe provided on the installation base is provided with a stop valve that can be freely opened and closed.

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