Construction machine

Abstract

A base part (4A1) of a lower movable arm (4A) forming a working device (4), an engine (7) serving as a power source, a cab (9), a cover part (10) serving as a right side structure, a fuel tank (11), and a frame upper space part (14) surrounded by a working oil tank (12) are formed on a rotating frame (5), and an energy accumulator (15) and a safety valve (20) are arranged in the frame upper space part (14), wherein the base part (4A1), the engine (7), the cab (9), the cover part (10), the fuel tank (11) and the working oil tank (12) form the base part (4A1) of a lower movable arm (4A) of the working device (4). On this basis, the relief valve (20) is disposed at a position higher than a piping connection section (15A) of the accumulator (15).

Description

Technical Field

[0001] The present invention relates to a construction machine such as a hydraulic excavator equipped with an accumulator. Background Art

[0002] A hydraulic excavator, which is a representative example of an engineering machine, includes a self-propelled lower traveling body, an upper revolving body mounted on the lower traveling body in a revolving manner, and a working device provided on the front side of the upper revolving body. The working device includes a boom, an arm, and a bucket. A base portion, which is the base end side of the boom, is rotatably mounted on the front side of a revolving frame.

[0003] The upper revolving body includes: a revolving frame of a base part with a working device mounted on the front side, a power source such as an engine and an electric motor which is installed on the rear side of the revolving frame and drives a hydraulic pump, a cab which is located on the left side of the base part and installed on the revolving frame, and a right side structure which is located on the right side of the base part and installed on the revolving frame. The right side structure is composed of, for example, a fuel tank, a working oil tank, a cover member for storing a control valve device, etc.

[0004] Some hydraulic excavators include an accumulator connected to a hydraulic cylinder to store hydraulic pressure (energy), a safety valve connected to a hydraulic oil tank, and a connecting pipe connecting the accumulator and the safety valve (Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2016-188544 Summary of the invention

[0008] However, in addition to the above-mentioned equipment, a plurality of hydraulic devices are provided on the upper slewing body of the hydraulic excavator, and a plurality of hydraulic pipes are arranged to connect these hydraulic devices. Therefore, when installing an accumulator or a safety valve behind the vehicle body, the accumulator and the safety valve must be arranged at a position avoiding the existing hydraulic devices and hydraulic pipes, or the hydraulic pipes must be arranged in a roundabout way. Therefore, the hydraulic excavator of Patent Document 1 has the following problems: it is difficult to easily maintain the accumulator, the safety valve, the hydraulic pipes, etc. or to arrange them at a position where they can be easily installed, resulting in reduced maintainability and increased installation costs.

[0009] The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a construction machine capable of improving maintainability and reducing installation costs by arranging an accumulator, a safety valve, and hydraulic piping at appropriate positions.

[0010] In the present invention, the construction machinery includes: a self-propelled lower traveling body; an upper rotating body, which is mounted on the lower traveling body in a rotating manner; and a working device, which is arranged on the front side of the upper rotating body and driven by a hydraulic cylinder, and the upper rotating body has: a rotating frame, on the front side of which a base of the working device is installed; a power source, which is arranged on the rear side of the rotating frame and is used to drive a hydraulic pump; a cab, which is located on the left side of the base and is arranged on the rotating frame; a right structural body, which is located on the right side of the base and is arranged on the rotating frame The slewing frame is provided with a working oil tank for storing working oil supplied to the hydraulic pump; an accumulator connected to the hydraulic cylinder; a safety valve connected to the working oil tank; and a connecting pipe connecting a pipe connecting portion of the accumulator and the safety valve, wherein a space portion on the frame is formed on the revolving frame and is surrounded by the base portion of the working device, the power source, the cab and the right side structure in front, back, left and right directions, the accumulator and the safety valve are arranged in the space portion on the frame, and the safety valve is arranged at a position higher than the pipe connecting portion of the accumulator.

[0011] According to the present invention, the accumulator, the safety valve, and the hydraulic pipe can be arranged at appropriate positions, and the maintainability can be improved and the installation cost can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a left side view showing a wheeled hydraulic excavator to which the embodiment of the present invention is applied.

[0013] Figure 2 It is a perspective view showing the front side portion of the upper revolving body with the cab omitted.

[0014] Figure 3 It is a cross-sectional view of the upper rotating body.

[0015] Figure 4 This is a perspective view showing an accumulator and a safety valve in an enlarged manner.

[0016] Figure 5 It is a plan view showing the accumulator and the surrounding area of ​​the safety valve in an enlarged manner.

[0017] Figure 6 It is a perspective view showing the mounting structure of the accumulator with respect to the right vertical plate. DETAILED DESCRIPTION

[0018] In the following, a wheeled hydraulic excavator is used as a representative example of a construction machine according to an embodiment of the present invention. Figures 1 to 6 In addition, in this embodiment, the description is made using the front-rear direction and the left-right direction viewed from the operator sitting on the driver's seat in the cab.

[0019] exist Figure 1 In the figure, the hydraulic excavator 1 is a wheeled hydraulic excavator having a self-propelled wheeled lower traveling body 2, and the lower traveling body 2 has left and right front wheels 2A and left and right rear wheels 2B (only the left side is shown in the figure). The hydraulic excavator 1 has an upper revolving body 3 mounted on the lower traveling body 2 in a revolving manner, and a working device 4 provided on the front side of the upper revolving body 3.

[0020] The working device 4 is provided at the front side of the upper revolving body 3. The working device 4 is composed of a lower boom 4A, an upper boom 4B, an arm 4C, a bucket 4D, and an arm cylinder 4E, a positioning cylinder 4F, an arm cylinder 4G, and a bucket cylinder 4H for driving (rotating) the lower boom 4A, the upper boom 4B, the arm 4C, and the bucket 4D. The lower boom 4A is mounted on the front side of the revolving frame 5 of the upper revolving body 3 in such a manner that a base portion 4A1 at the base end side can be rotated in the up-down direction, the upper boom 4B is mounted on the front end side of the lower boom 4A in a rotatable manner, the arm 4C is mounted on the front end side of the upper boom 4B in a rotatable manner, and the bucket 4D is mounted on the front end side of the arm 4C in a rotatable manner.

[0021] The working device 4 is equipped with a bucket 4D as an attachment (working tool), but an attachment other than the bucket 4D such as a grapple may be installed instead of the bucket 4D. In addition, as the boom of the working device, a boom composed of one member bent into an L-shape may be used instead of a boom composed of two members, the lower boom 4A and the upper boom 4B.

[0022] The revolving frame 5 is formed as a supporting structure that expands in the left-right direction and extends in the front-back direction. Figure 2 As shown, the revolving frame 5 is composed of: a thick-walled bottom plate 5A extending in the front-to-back direction; a left longitudinal plate 5B and a right longitudinal plate 5C erected on the bottom plate 5A and extending in the front-to-back direction at predetermined intervals in the left-right direction; a plurality of left extension beams 5D extending to the left from the bottom plate 5A and the left longitudinal plate 5B; a plurality of right extension beams (not shown) extending to the right from the bottom plate 5A and the right longitudinal plate 5C; a left frame 5E extending in the front-to-back direction at the front ends of the plurality of left extension beams 5D; and a right frame (not shown) extending in the front-to-back direction at the front ends of the plurality of right extension beams. The base 4A1 constituting the lower boom 4A of the working device 4 is rotatably mounted to the front of the left longitudinal plate 5B and the right longitudinal plate 5C.

[0023] like Figure 1 As shown, the counterweight 6 is provided at the rear portion of the revolving frame 5. The counterweight 6 is configured as a weight that is balanced with the weight of the working device 4.

[0024] The engine 7 as a power source is arranged on the rear side of the revolving frame 5 (in front of the counterweight 6). The engine 7 is arranged in front of the counterweight 6 at a predetermined distance from the base 4A1 of the lower boom 4A to the rear side. The engine 7 is configured as an internal combustion engine and is mounted in a horizontal state extending in the left-right direction. In addition, as a power source, an electric motor or a hybrid engine composed of an engine and an electric motor may be used instead of the engine 7.

[0025] The hydraulic pump 8 is installed, for example, on the left side of the engine 7 (at Figure 1 As a result, the hydraulic pump 8 is driven by the engine 7 to discharge the hydraulic oil from the hydraulic oil tank 12 described later as pressure oil.

[0026] The cab 9 is provided on the left front side of the revolving frame 5. The cab 9 is arranged on the left side of the base 4A1 of the lower boom 4A, specifically, at the frontmost part between the left vertical plate 5B and the left side frame 5E of the revolving frame 5. The cab 9 forms an operating room for the operator therein. The cab 9 is provided with a driver's seat for the operator, a steering wheel for driving, an operating lever for operation, etc. (all not shown).

[0027] like Figure 2 , Figure 3 As shown, the cover member 10 is provided on the right front side of the revolving frame 5. The cover member 10 has a hollow box structure, and contains control valve devices for supplying and discharging pressure oil to various hydraulic actuators, tools for maintenance, etc. (all not shown). In addition, the cover member 10 has a stepped upper surface 10A, and the upper revolving body 3 can be raised and lowered by placing a foot on the stepped upper surface 10A.

[0028] The fuel tank 11 is located immediately after the cover member 10 and is provided on the right side of the revolving frame 5. The fuel tank 11 is formed as a rectangular parallelepiped container that is long in the vertical direction, and stores fuel supplied to the engine 7 therein. In addition, the upper surface 11A of the fuel tank 11 serves as a scaffold for operators to carry when performing maintenance work or the like.

[0029] The hydraulic oil tank 12 is located immediately after the fuel tank 11 and is provided on the right side of the revolving frame 5. The hydraulic oil tank 12 is formed as a vertically elongated rectangular parallelepiped container similarly to the fuel tank 11, and hydraulic oil supplied to the hydraulic pump 8 is stored therein.

[0030] Here, the cover member 10, the fuel tank 11, and the hydraulic oil tank 12, which are arranged on the front side of the engine 7 and on the right side of the right vertical plate 5C of the revolving frame 5, constitute the right structural body. In addition, when an electric motor is used as a power source, the fuel tank 11 can be eliminated and other structural bodies, such as a battery case for storing a battery for the electric motor, can be arranged.

[0031] The rear cover 13 is provided between the counterweight 6 and the hydraulic oil tank 12 so as to cover the engine 7, the hydraulic pump 8, etc. The front side portion of the upper surface 13A of the rear cover 13 serves as a scaffold on which an operator mounts when performing maintenance work or the like.

[0032] The frame upper space portion 14 is provided at the front side portion of the revolving frame 5. Specifically, in the frame upper space portion 14, the base portion 4A1 of the lower boom 4A constituting the working device 4 becomes the front wall, the engine 7 becomes the rear wall, the right surface of the cab 9 becomes the left wall, and the left surface of the right structural body constituted by the cover member 10, the fuel tank 11, and the working oil tank 12 becomes the right wall. Thus, the frame upper space portion 14 is formed into a rectangular space extending in the front-rear direction and surrounded by the front, rear, left, and right sides. The frame upper space portion 14 is provided with the accumulator 15, the safety valve 20, the connecting pipe 21, etc., which will be described later.

[0033] The accumulator 15 is connected to the boom cylinder 4E as a hydraulic cylinder via, for example, a safety valve 20 described later. The accumulator 15 is formed as a cylindrical container with pressure resistance, and is arranged in a longitudinal state extending in the up-down direction. The accumulator 15 is located on the right side of the frame upper space portion 14 and is arranged at a position lower than the upper surface 11A of the fuel tank 11 constituting the right structural body. In detail, the accumulator 15 is arranged on the left side of the right longitudinal plate 5C of the revolving frame 5, between the position of the axis when the base 4A1 of the lower boom 4A is rotatably mounted on the left longitudinal plate 5B and the right longitudinal plate 5C and the upper surface 11A of the fuel tank 11. As a result, the accumulator 15 does not hinder the vision of the operator in the cab 9 when observing the right side, and can make the appearance of the upper revolving body 3 good, and does not become an obstacle when the operator moves on the upper surface 11A of the fuel tank 11 and the upper surface 13A of the rear cover 13, which serve as a scaffold.

[0034] On the other hand, a pipe connection portion 15A is provided at the bottom of the accumulator 15. The pipe connection portion 15A is composed of a hose joint called an elbow in which the direction of installation to the bottom surface of the accumulator 15 and the connection port 15A1 connected to the connection pipe 21 are arranged at right angles. Figure 3 , Figure 6 As shown, the pipe connection portion 15A is installed so that the connection port 15A1 faces the side opposite to the safety valve 20 , and is installed so as to face the front side in the embodiment.

[0035] The accumulator 15 allows the working oil (pressure oil) discharged from the boom cylinder 4E to flow into the accumulator 15, thereby storing the pressure (energy) of the pressure oil. On the other hand, the accumulator 15 controls the flow rate of the pressure oil flowing from the boom cylinder 4E during travel, thereby suppressing the shaking of the working device 4 during travel.

[0036] The bracket support member 16 is located near the rear side of the lower boom 4A and is attached to the right side surface of the right vertical plate 5C. The bracket support member 16 is composed of a long thick plate extending upward from the right side surface of the right vertical plate 5C. An upper support portion 16A to which the upper part of the accumulator mounting bracket 18 is attached is provided in a manner protruding to the left at the upper part of the bracket support member 16. In addition, a lower support portion 17 to which the lower part of the accumulator mounting bracket 18 is attached is provided in a manner extending upward on the left side surface of the right vertical plate 5C directly below the upper support portion 16A.

[0037] The accumulator mounting bracket 18 is formed as a plate body facing the bracket support member 16 at a predetermined interval in the left-right direction. The upper portion of the accumulator mounting bracket 18 is mounted to the upper support portion 16A, and the lower portion is mounted to the lower support portion 17. The accumulator 15 is mounted on the left side surface of the accumulator mounting bracket 18 in a state extending in the up-down direction (vertical direction).

[0038] The insertion space 19 is formed between the bracket support member 16 and the accumulator mounting bracket 18. Figure 4 As shown, the insertion space 19 is a space for inserting a plurality of hydraulic pipes 24 to 27 described later. Thus, the plurality of hydraulic pipes 24 to 27 do not need to bypass the accumulator 15 and can be laid out in a short and simple manner.

[0039] The safety valve 20 is disposed at the rear side of the frame upper space portion 14 and is connected to the hydraulic oil tank 12. The safety valve 20 opens when the pressure of the hydraulic oil returned from the boom cylinder 4E exceeds a preset pressure, and discharges the hydraulic oil to the hydraulic oil tank 12. Figure 5 As shown in FIG. 1 , the safety valve 20 is arranged at a position rearward of the accumulator 15 and offset to the left with respect to the accumulator 15 .

[0040] On this basis, if Figure 3 As shown in FIG. 1 , the safety valve 20 is arranged at a position higher than the piping connection portion 15A of the accumulator 15 by a dimension H. Thus, even if air is mixed into the hydraulic circuit when the accumulator 15 is installed, the air can be discharged from the safety valve 20 at a position higher than the piping connection portion 15A of the accumulator 15 to the hydraulic oil tank 12 when the driving control system described later is activated. That is, the exhaust work when forming the driving control system can be omitted.

[0041] The connecting pipe 21 connects the pipe connection portion 15A of the accumulator 15 to the safety valve 20. The connecting pipe 21 is formed of a bendable pressure-resistant hose having strength to withstand the high pressure of the pressure oil. One end of the connecting pipe 21 is connected to the safety valve 20, and the other end is connected to the connection port 15A1 of the pipe connection portion 15A.

[0042] Here, the pressure-resistant hose has a multi-layer structure to withstand high pressure, so the bending radius becomes large. Therefore, considering the bending radius of the connecting pipe, the positional relationship between the accumulator and the safety valve is limited to a position where they can be connected through the connecting pipe composed of the pressure-resistant hose. Therefore, the accumulator and the safety valve cannot be arranged at a relatively close position.

[0043] In contrast, the connection pipe 21 of the present embodiment extends from the safety valve 20 toward the accumulator 15, and is connected to the connection port 15A1 of the pipe connection portion 15A at a position passing through the left side of the accumulator 15. As a result, the distance from the safety valve 20 to the connection port 15A1 of the pipe connection portion 15A can be increased. In other words, the accumulator 15 and the safety valve 20 can be arranged at relatively close positions while keeping the bending radius of the connection pipe 21 unchanged.

[0044] The driving control system is described. The driving control system is a system that reduces vibration during driving by making the working device 4 move actively during driving, and reduces the load overflow from the bucket 4D and the fatigue of the operator. The driving control system connects the hydraulic circuit on the bottom side of the boom cylinder 4E supporting the working device 4 to the accumulator 15, and connects the hydraulic circuit on the rod side of the boom cylinder 4E to the discharge part (working oil tank 12), thereby using the accumulator 15 to alleviate the vibration when the working device 4 moves up and down due to the unevenness of the ground.

[0045] The driving control system is composed of the accumulator 15, the safety valve 20, the bottom side valve 22 connected to the bottom side of the boom cylinder 4E, and the rod side valve 23 connected to the rod side of the boom cylinder 4E (see Figure 5 ) and so on.

[0046] In addition, the hydraulic pipes 24 to 27 are connected to the control valve device in the cover member 10. The hydraulic pipes 24 to 27 are formed of metal pipes or pressure-resistant hoses. The hydraulic pipes 24 to 27 extend in the front-rear direction through the insertion space 19 between the bracket support member 16 and the accumulator mounting bracket 18. The hydraulic pipes 24 to 27 are inserted into the insertion space 19, so there is no need to bypass the accumulator 15, so they can be formed shorter and can be laid with a simple fixing structure.

[0047] The hydraulic excavator 1 according to the present embodiment has the above-described configuration, and the operation thereof will be described below.

[0048] The operator gets on the cab 9, sits on the driver's seat and starts the engine 7. In this state, the operator can operate the steering wheel for driving, etc. to make the lower driving body 2 travel. In addition, the operator can perform a rotation operation of the upper revolving body 3, an excavation operation of sand and soil by the working device 4, etc. by operating the operating lever for operation, etc.

[0049] Here, the driving control system is operated when the working device 4 is traveling while digging sand and soil with the bucket 4D. The driving control system can alleviate the vibration of the working device 4 by pumping pressure oil between the boom cylinder 4E and the accumulator 15 when the lower boom 4A of the working device 4 moves up and down due to the unevenness of the ground.

[0050] Thus, according to the present embodiment, a frame upper space portion 14 is formed on the revolving frame 5, which is surrounded by the base portion 4A1 of the lower boom 4A constituting the working device 4, the engine 7 as a power source, the cab 9, and the cover member 10 as a right structural body, the fuel tank 11, and the working oil tank 12, and the accumulator 15 and the safety valve 20 are arranged in the frame upper space portion 14. On this basis, the safety valve 20 is arranged at a position higher than the piping connection portion 15A of the accumulator 15.

[0051] Therefore, the accumulator 15 and the safety valve 20 can be arranged at an appropriate position where the safety valve 20 is higher than the piping connection portion 15A of the accumulator 15. Therefore, even if air is mixed into the hydraulic circuit when the accumulator 15 is installed, the air can be discharged from the safety valve 20 at a position higher than the piping connection portion 15A of the accumulator 15 to the hydraulic oil tank 12 when the driving control system is activated. As a result, the exhaust work when forming the driving control system can be omitted, and the maintainability can be improved and the installation cost can be reduced.

[0052] The connection port 15A1 of the pipe connection portion 15A of the accumulator 15 is disposed toward the front side, which is opposite to the safety valve 20 . The connection pipe 21 extends toward the front side from the safety valve 20 toward the accumulator 15 , and is connected to the connection port 15A1 at a position passing the side of the accumulator 15 .

[0053] Therefore, even when the accumulator 15 and the safety valve 20 are connected via the connecting pipe 21 composed of a pressure-resistant hose whose bending radius cannot be reduced, the accumulator 15 and the safety valve 20 can be arranged at a relatively close position, and the interval between the connection positions based on the connecting pipe 21 can be increased. As a result, the accumulator 15 and the safety valve 20 can be arranged at a relatively close position while maintaining the bending radius of the connecting pipe 21. As a result, the accumulator 15 and the safety valve 20 can be installed at a position where maintenance can be easily performed and a position where installation can be easily performed, and the maintainability can be improved and the installation cost can be reduced.

[0054] Furthermore, the revolving frame 5 has a left vertical plate 5B and a right vertical plate 5C, which are erected and extended in the front-rear direction at intervals in the left-right direction, and are installed with a base 4A1 of the lower boom 4A constituting the working device 4, and the right vertical plate 5C is provided with a bracket support member 16 extending upward, and an accumulator mounting bracket 18 mounted on the bracket support member 16 and having the accumulator 15 mounted thereon, and an insertion space 19 for inserting the hydraulic pipes 24 to 27 is formed between the bracket support member 16 and the accumulator mounting bracket 18. Thus, the plurality of hydraulic pipes 24 to 27 are inserted into the insertion space 19, and do not need to bypass the accumulator 15, so they can be formed shorter and can be laid out with a simple fixed structure. In this regard, it is also possible to achieve improved maintainability and reduced installation costs.

[0055] In the embodiment, the wheeled hydraulic excavator 1 is described as an example of a construction machine. However, the present invention is not limited to this, and can be widely applied to other construction machines such as crawler hydraulic excavators.

[0056] Explanation of symbols

[0057] 1—Hydraulic excavator (construction machinery); 2—lower traveling body; 3—upper rotating body; 4—working device; 4A—lower boom (boom); 4A1—base; 4E—boom cylinder (hydraulic cylinder); 5—rotating frame; 5A—bottom plate; 5B—left longitudinal plate; 5C—right longitudinal plate; 7—engine (power source); 8—hydraulic pump; 9—operating cab; 10—hood component (right structural body); 11—fuel tank (right structural body); 12—working oil tank (right structural body); 14—space portion on frame; 15—accumulator; 15A—piping connection portion; 15A1—connection port; 16—bracket supporting component; 18—accumulator mounting bracket; 19—insertion space portion; 20—safety valve; 21—connecting piping; 24~27—hydraulic piping.

Claims

1. An engineering machine, comprising: A lower traveling body capable of self-propelled movement; an upper rotating body mounted on the lower traveling body in a rotatable manner; as well as A working device is arranged at the front side of the upper rotating body and driven by a hydraulic cylinder, The upper rotating body comprises: A revolving frame having a base of the working device mounted on the front side thereof; A power source, which is arranged at the rear side of the revolving frame and is used to drive a hydraulic pump; A cab, which is located on the left side of the base portion and is arranged on the revolving frame; a right structural body, which is located on the right side of the base portion, is provided on the revolving frame, and includes a working oil tank storing working oil supplied to the hydraulic pump; an accumulator connected to the hydraulic cylinder; a safety valve connected to the working oil tank; and a connecting pipe connecting a pipe connection portion of the accumulator and the safety valve, The engineering machine is characterized in that: The revolving frame has a frame upper space portion surrounded by the base of the working device, the power source, the cab, and the right structural body in front, back, left, and right directions. The accumulator and the safety valve are arranged in the space above the frame. The safety valve is arranged at a position higher than the pipe connecting portion of the accumulator.

2. The construction machinery according to claim 1, characterized in that: The pipe connection portion of the accumulator is arranged so that the connection port faces the side opposite to the safety valve. The connecting pipe extends from the safety valve toward the accumulator, and is connected to the connecting port at a position passing a side of the accumulator.

3. The construction machine according to claim 1, characterized in that: The revolving frame includes a left vertical plate and a right vertical plate, which are erected in a spaced relationship in the left-right direction and extend in the front-rear direction, and to which the base portion of the working device is mounted. The right vertical plate is provided with a bracket support member extending upward, and an accumulator mounting bracket mounted on the bracket support member and having the accumulator mounted thereon. An insertion space portion for inserting a hydraulic pipe is formed between the bracket support member and the accumulator mounting bracket.

4. The construction machinery according to claim 1, characterized in that: The working device includes a boom having the base portion, The hydraulic cylinder includes a boom cylinder for driving the boom, The accumulator is connected to the boom cylinder.

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