Construction machinery

Abstract

A manifold (33) of a closed-circuit control valve apparatus (32) disposed rearward of a left-side revolving hydraulic motor (8) comprises: a valve attachment area (33E) that is provided in a left-right-direction central portion of the manifold (33) and in which a control valve (34) is attached; and a pipe attachment area (33F) that is provided outward of the valve attachment area (33E) in the left-right direction and in which a closed-circuit actuator side pipe (47) is attached. A manifold (42) of an open-circuit control valve apparatus (41) disposed rearward of a right-side revolving hydraulic motor (9) comprises: a valve attachment area (42E) that is provided in a left-right-direction central portion of the manifold (42) and in which a control valve (43) is attached; and a pipe attachment area (42F) that is provided outward of the valve attachment area (42E) in the left-right direction and in which an open-circuit actuator side pipe (48) is attached.

Description

Technical Field

[0001] The present invention relates to construction machinery such as a hydraulic excavator, and more particularly to construction machinery provided with a plurality of control valves for controlling hydraulic actuators.

Background Art

[0002] Generally, a hydraulic excavator, which is a typical example of construction machinery, includes a self-propelled lower traveling body, an upper revolving body rotatably provided on the lower traveling body via a slewing device, and a working device provided at the front of the upper revolving body. Further, the hydraulic excavator is provided with hydraulic actuators such as a traveling hydraulic motor for driving the lower traveling body, a slewing hydraulic motor of the slewing device for slewing the upper revolving body, a boom cylinder, an arm cylinder, and a bucket cylinder for operating the working device. Furthermore, the upper revolving body of the hydraulic excavator includes a slewing frame rotatably supported on the lower traveling body via a slewing device, an engine as a prime mover provided on the rear side of the slewing frame, a hydraulic pump provided on the engine, and a control valve device provided on the slewing frame in front of the engine for controlling the hydraulic actuator. The hydraulic excavator also includes a plurality of pump-side pipes connecting the hydraulic pump and the control valve device, and a plurality of actuator-side pipes connecting the control valve device and a plurality of actuators (the traveling hydraulic motor of the traveling device, each hydraulic cylinder of the working device, and the slewing hydraulic motor of the slewing device).

[0003] Then, the hydraulic excavator drives the hydraulic pump with the engine and supplies the hydraulic oil (pressure oil) discharged from the hydraulic pump to the hydraulic actuator through the control valve device and each pipe. Thereby, the hydraulic excavator operates the traveling device, the slewing device, and the working device.

[0004] In recent years, it has been desired to reduce energy losses (flow losses and pressure losses) in hydraulic excavators to achieve energy savings. Therefore, as a hydraulic system for supplying hydraulic oil from a hydraulic pump to a hydraulic actuator, a closed-circuit system is used in which a dedicated closed-circuit hydraulic pump is connected to the hydraulic actuator and hydraulic oil is supplied and discharged between the hydraulic actuator and the dedicated closed-circuit hydraulic pump (Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] In a closed-circuit system, two closed-circuit pipes for circulating hydraulic oil between the hydraulic pump and the hydraulic actuator are required. Specifically, for example, when operating four hydraulic actuators such as a boom cylinder, an arm cylinder, a bucket cylinder, and a swing hydraulic motor of a hydraulic excavator in a closed-circuit system, at least four closed-circuit hydraulic pumps and eight closed-circuit pipes are required. In addition, even when configuring the drive system of the traveling device with an open-circuit pump as disclosed in Patent Document 1, a plurality of open-circuit pipes for operating the traveling hydraulic motor are required.

[0007] Therefore, there are many hydraulic pipes around the control valve device. As a result, it is difficult to secure a space for attaching and detaching each control valve attached to the control valve device and a swing hydraulic motor arranged close to the control valve device and for maintaining them, and there is a problem that the workability of each operation deteriorates.

[0008] The present invention has been made in view of the problems of the above-described prior art, and an object of the present invention is to provide a construction machine capable of improving workability such as detachment work and maintenance of a control valve, a swing hydraulic motor, etc. by securing a space for working around the control valve device.

[0009] The present invention Equipped with crawlers rotated by a traveling hydraulic motor comprises a self-propelled lower traveling body, an upper swing body rotatably provided on the lower traveling body via a swing device, and provided at the front part of the upper swing body Each of which a hydraulic cylinder boom cylinder, arm cylinder and bucket cylinder by which Each is rotated including a boom, an arm and a bucket a working device, a hydraulic system for driving the lower traveling body, the upper slewing body and the working device; and is provided with a swing wheel that rotatably supports the upper swing body on the lower traveling body, and a swing hydraulic motor that is provided on the upper swing body and swings the upper swing body along the swing wheel on the lower traveling body. The upper swing body includes a swing frame rotatably supported on the lower traveling body via the swing wheel, a prime mover provided on the rear side of the swing frame, a hydraulic pump driven by the prime mover, and a control valve device in which a plurality of control valves are attached to a manifold provided on the swing frame in front of the prime mover. A plurality of pump-side pipes connecting the hydraulic pump and the control valve device, and a plurality of actuator-side pipes connecting the control valve device and the cylinder of the working device and the swing hydraulic motor of the swing device. In the construction machine, the control valve device includes the plurality of control valves located on the front surface facing the front of the manifold, and a plurality of pipe connection ports located on the front surface of the manifold to which the plurality of actuator-side pipes are connected, and the front surface of the manifold is arranged behind the swing hydraulic motor so as to face the swing hydraulic motor, and a valve mounting area where the plurality of control valves are attached is located at the center in the left-right direction of the front surface of the manifold. The hydraulic system includes a closed circuit system that uses the boom cylinder, the arm cylinder and the bucket cylinder, and the slewing hydraulic motor as hydraulic actuators respectively, and supplies and discharges hydraulic oil to and from each of the hydraulic actuators, and an open circuit system that supplies hydraulic oil to the closed circuit system, uses the traveling hydraulic motor as a hydraulic actuator, and supplies hydraulic oil from an oil tank to each of the hydraulic actuators; The upper swing body includes a swing frame rotatably supported on the lower traveling body via the swing wheel, a prime mover provided on the rear side of the swing frame, a hydraulic pump driven by the prime mover, and a control valve device in which a plurality of control valves are attached to a manifold provided on the swing frame in front of the prime mover. A plurality of pump-side pipes connecting the hydraulic pump and the control valve device, and a plurality of actuator-side pipes connecting the control valve device and the cylinder of the working device and the swing hydraulic motor of the swing device. In the construction machine, the control valve device includes the plurality of control valves located on the front surface facing the front of the manifold, and a plurality of pipe connection ports located on the front surface of the manifold to which the plurality of actuator-side pipes are connected, and the front surface of the manifold is arranged behind the swing hydraulic motor so as to face the swing hydraulic motor, and a valve mounting area where the plurality of control valves are attached is located at the center in the left-right direction of the front surface of the manifold. , a plurality of hydraulic pumps for the closed circuit and a plurality of open circuits respectively included in the closed circuit system and the open circuit system a hydraulic pump and the prime mover , the plurality of hydraulic pumps for the closed circuit and the plurality of hydraulic pumps for the open circuit is located on the front side of and provided on the swing frame Rectangular parallelepiped-shaped a control valve device in which a plurality of control valves are attached to a manifold, and a plurality of hydraulic pumps for the closed circuit and the plurality of open circuits a plurality of pump-side pipes connecting the hydraulic pump and the control valve device, and the control valve device and the boom cylinder, the arm cylinder and the bucket cylinder of the working device, the swing hydraulic motor of the swing device , and the traveling hydraulic motor and a plurality of actuator-side pipes connecting them. In the construction machine, the control valve device includes the plurality of control valves located on the front surface facing the front of the manifold, and a plurality of pipe connection ports located on the front surface of the manifold to which the plurality of actuator-side pipes are connected, and the front surface of the manifold is arranged behind the swing hydraulic motor so as to face the swing hydraulic motor, and the front surface of the manifold In at the center in the left-right direction is a valve mounting area where the plurality of control valves are attached is provided ,On the front surface of the manifold the valve mounting area With the valve mounting area sandwiched therebetween on the outer sides in the left - right direction Each is the pipe connection port is provided and to , extending forward toward the front of the manifold the pipe mounting area where the plurality of actuator - side pipes are mounted is provided , On the upper surface of the manifold, the plurality of pump-side pipes are connected from above .

[0010] According to the present invention, around the control valve device, a space for performing work can be secured, and the workability of attaching / detaching operations such as control valves and swing hydraulic motors, and maintenance can be improved.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0012] Hereinafter, as a representative example of a construction machine according to an embodiment of the present invention, a hydraulic excavator will be taken as an example and described in detail with reference to FIGS. 1 to 5.

[0013] In FIG. 1, a hydraulic excavator 1, which is a representative example of a construction machine, is used for earth - and - sand excavation work and the like. The hydraulic excavator 1 includes a crawler - type lower traveling body 2 that can travel by itself, an upper swing body 5 that is rotatably provided on the lower traveling body 2 and constitutes a vehicle body together with the lower traveling body 2, and a working device 20 provided at the front of the upper swing body 5. The hydraulic excavator 1 performs earth - and - sand excavation work and the like using the working device 20.

[0014] The lower traveling body 2 includes a track frame 2A, drive wheels 2B provided on both left and right sides of the track frame 2A, idler wheels 2C provided on both left and right sides of the track frame 2A on the opposite side of the drive wheels 2B in the front-rear direction, and a crawler belt 2D wound around the drive wheels 2B and the idler wheels 2C (only the right side is shown in the figure). The left drive wheel is rotationally driven by a left traveling hydraulic motor 3 (see Fig. 5). Also, the right drive wheel 2B is rotationally driven by a right traveling hydraulic motor 4 (see Fig. 5). The traveling hydraulic motors 3 and 4 constitute a hydraulic actuator.

[0015] The slewing device 6 is a device for slewing the upper slewing body 5 on the lower traveling body 2. The slewing device 6 includes a slewing ring 7 (see Fig. 1) consisting of a large-diameter bearing that rotatably supports the upper slewing body 5 on the lower traveling body 2, and one or more, for example, two slewing hydraulic motors 8 and 9 (see Fig. 5) provided on the upper slewing body 5 and configured to slewing the upper slewing body 5 along the slewing ring 7 on the lower traveling body 2. The two slewing hydraulic motors 8 and 9 constitute a hydraulic actuator.

[0016] The two slewing hydraulic motors 8 and 9 are provided on the slewing frame 10 via a speed reduction device (not shown). As shown in Fig. 2, the two slewing hydraulic motors 8 and 9 are arranged side by side in the left-right direction between a center joint 17, a closed-circuit control valve device 32, and an open-circuit control valve device 41, which will be described later.

[0017] As shown in Fig. 3, the left slewing hydraulic motor 8 is arranged in front of the closed-circuit control valve device 32. Specifically, the left slewing hydraulic motor 8 is arranged in front of a valve mounting area 33E (see Fig. 4) located at the center in the left-right direction of the manifold 33, that is, in a first space 49 (see Fig. 3) which will be described later. Also, the right slewing hydraulic motor 9 is arranged in front of the open-circuit control valve device 41. Specifically, the right slewing hydraulic motor 9 is arranged in front of a pipe mounting area 42F (see Fig. 4) located on the left outer side of the manifold 42, that is, in a second space 50 (see Fig. 3) which will be described later. A closed-circuit actuator-side pipe 47, which will be described later, is connected to the two slewing hydraulic motors 8 and 9.

[0018] As shown in FIGS. 1 and 2, the upper swing body 5 includes a swing frame 10 forming a support structure with a working device 20 provided on the front side, a cab 11 mounted on the left front side of the swing frame 10 and forming a driver's cab inside, a counterweight 12 attached to the rear of the swing frame 10 to balance the weight with the working device 20, and a building 19 located between the cab 11 and the counterweight 12 and mounted on the swing frame 10 for housing an engine 14 and the like, which will be described later.

[0019] Here, inside the cab 11, a driver's seat (not shown) on which the operator sits is provided. Also, on the front, left, and right sides of the driver's seat, an operating device 13 (see FIG. 5) for operating the hydraulic excavator 1 is provided. As an example of the combination of the operation target and the lever operation, the operating device 13 includes a left operating lever 13A for operating the swing hydraulic motors 8 and 9 and an arm cylinder 25, which will be described later, a right operating lever 13B for operating a boom cylinder 24 and a bucket cylinder 26, which will be described later, and left and right travel levers and pedals 13C and 13D for operating the left travel hydraulic motor 3 and the right travel hydraulic motor 4.

[0020] The operating device 13 is connected to a controller 55, which will be described later, via a signal line or the like. By operating the operating device 13, the operator can swing the upper swing body 5, rotate the working device 20, or make the lower traveling body 2 travel.

[0021] As shown in Fig. 2, the engine 14 as the prime mover is provided on the slewing frame 10 and is located on the front side of the counterweight 12. The engine 14 is configured as, for example, a diesel engine. One engine 14 is provided in a horizontally mounted state extending in the left - right direction on the rear side of the slewing frame 10. For example, on the right side of the engine 14, a plurality of closed - circuit hydraulic pumps 31, open - circuit hydraulic pumps 40, etc. are attached via a power transmission device 15. The power transmission device 15 has a plurality of gear mechanisms (not shown) that transmit the rotation of the output shaft of the engine 14, and each gear mechanism is connected to a plurality of closed - circuit hydraulic pumps 31, open - circuit hydraulic pumps 40, etc. Further, on the left side of the engine 14, a heat exchange device 16 composed of a radiator, an oil cooler, a capacitor, etc. is arranged.

[0022] Note that as the prime mover, a hybrid prime mover combining a diesel engine and an electric motor or an electric motor alone may be used. On the other hand, the prime mover may be provided in a vertically mounted state extending in the front - rear direction of the upper slewing body 5. Also, the prime mover may be configured to be arranged with two side - by - side in the left - right direction.

[0023] The center joint 17 is located at the center of the slewing ring 7 of the slewing device 6 and is provided between the lower traveling body 2 and the upper slewing body 5. The center joint 17 forms a joint portion that allows hydraulic oil and electricity (signals) to flow between the lower traveling body 2 and the upper slewing body 5 even when the upper slewing body 5 is slewing with respect to the lower traveling body 2. An open - circuit actuator - side pipe 48, etc. is connected to the center joint 17.

[0024] The hydraulic oil tank 18 stores hydraulic oil for supplying to the open - circuit hydraulic pump 40 and the like, and is provided on the slewing frame 10. The hydraulic oil tank 18 is formed, for example, as a rectangular parallelepiped container extending in the front - rear direction, and is disposed on the right side of the slewing frame 10. Specifically, as shown in FIG. 3, the hydraulic oil tank 18 is adjacent to the right side of the open - circuit control valve device 41 described later and is disposed apart from the closed - circuit control valve device 32. Also, one closed - circuit tank - side pipe 53 extending from the closed - circuit control valve device 32 and a plurality of open - circuit tank - side pipes 54 extending from the open - circuit control valve device 41 are connected to the hydraulic oil tank 18.

[0025] The housing 19 is provided on the slewing frame 10 so as to cover devices including the slewing hydraulic motors 8, 9, the engine 14, the heat exchanger 16, the hydraulic oil tank 18, the closed - circuit hydraulic pump 31, and the open - circuit hydraulic pump 40. The housing 19 is formed, for example, in a box shape by attaching an iron plate or the like to a framework made of a plurality of steel materials.

[0026] As shown in FIG. 1, the working device 20 includes a boom 21 rotatably attached to the front side of the slewing frame 10, an arm 22 rotatably attached to the tip side of the boom 21, and a bucket 23 rotatably attached to the tip side of the arm 22. The boom 21, the arm 22, and the bucket 23 are driven by a boom cylinder 24, an arm cylinder 25, and a bucket cylinder 26, respectively, each of which is composed of a hydraulic cylinder. The boom cylinder 24 rotates the boom 21 with respect to the slewing frame 10, the arm cylinder 25 rotates the arm 22 with respect to the boom 21, and the bucket cylinder 26 rotates the bucket 23 with respect to the arm 22.

[0027] The boom cylinder 24, arm cylinder 25, and bucket cylinder 26 as hydraulic actuators extend and contract based on the hydraulic oil (pressure oil) from the closed-circuit hydraulic pump 31 and open-circuit hydraulic pump 40 described later, thereby changing the posture of the working device 20. That is, during excavation work such as earth and sand, for example, based on the operation of the left operation lever 13A and the right operation lever 13B, the boom cylinder 24, arm cylinder 25, and bucket cylinder 26 extend and contract, causing the boom 21, arm 22, and bucket 23 to rotate. Thereby, earth and sand can be excavated by the bucket 23.

[0028] Here, the boom cylinder 24, arm cylinder 25, and bucket cylinder 26 are configured as single-rod hydraulic cylinders and extend and contract based on the supply and discharge of hydraulic oil. That is, the boom cylinder 24, arm cylinder 25, and bucket cylinder 26 are composed of a tube, a piston slidably inserted into the tube and partitioning the inside of the tube into a bottom-side oil chamber and a rod-side oil chamber, and a rod with the base end side attached to the piston and the tip end side protruding outside the tube.

[0029] Next, the configurations of the closed-circuit systems 27 to 30 and the open-circuit systems 36 to 39 will be described with reference to FIG. 5.

[0030] In the present embodiment, the hydraulic system of the hydraulic excavator 1 is configured such that between four closed-circuit hydraulic pumps 31 and four hydraulic actuators, namely, the boom cylinder 24, arm cylinder 25, bucket cylinder 26, and swing hydraulic motors 8, 9, any one of the closed-circuit hydraulic pumps 31 can be connected to any one of the hydraulic actuators in a closed circuit (so as to form a closed circuit) by the closed-circuit control valve device 32. Then, the controller 55 controls the closed-circuit control valve device 32 according to the operation situation and working situation to perform control for switching the connection relationship between each hydraulic actuator and each closed-circuit hydraulic pump 31.

[0031] In this embodiment, a case where each of the hydraulic pumps 31 for a closed circuit is connected to each of the hydraulic actuators on a one-to-one basis to form four closed circuit systems will be described. Specifically, the closed circuit system 27 is a hydraulic system for driving the boom cylinder 24. The closed circuit system 28 is a hydraulic system for driving the arm cylinder 25. The closed circuit system 29 is a hydraulic system for driving the bucket cylinder 26. Further, the closed circuit system 30 is a hydraulic system for driving the swing hydraulic motors 8 and 9. In the following, a case where these four simplest closed circuit systems 27 to 30 are configured will be described.

[0032] The closed circuit system 27 includes a hydraulic pump 31 for a closed circuit driven by the engine 14, a later-described pipe 45 on the pump side for a closed circuit connecting the hydraulic pump 31 for a closed circuit and the boom cylinder 24, and a pipe 47 on the actuator side for a closed circuit.

[0033] Here, the configurations of the closed circuit systems 28 to 30 are substantially the same as the configuration of the closed circuit system 27. For this reason, the closed circuit systems 28 to 30 are given the same reference numerals as those used in the description of the closed circuit system 27, and detailed descriptions thereof are omitted.

[0034] As shown in FIGS. 2 and 5, a plurality of, for example, four hydraulic pumps 31 for a closed circuit that constitute the closed circuit systems 27 to 30 are attached to the right side of the engine 14 (power transmission device 15). The four hydraulic pumps 31 for a closed circuit are constituted by, for example, a variable displacement axial piston type hydraulic pump, an inclined shaft type hydraulic pump, a radial piston type hydraulic pump, or the like. One end of a pipe 45 on the pump side for a closed circuit, which will be described later, is connected to the four hydraulic pumps 31 for a closed circuit.

[0035] Next, the configurations of a control valve device 32 for a closed circuit and a control valve device 41 for an open circuit, which are the characteristic parts of this embodiment, will be described.

[0036] As shown in FIGS. 2 and 3, the control valve device 32 for the closed circuit is located on the front side of the engine 14 and is provided on the swing frame 10. Further, the control valve device 32 for the closed circuit is arranged behind the left swing hydraulic motor 8 in a horizontally placed state extending in the left-right direction. The control valve device 32 for the closed circuit includes a manifold 33, a control valve 34, and a filter 35, which will be described later.

[0037] The manifold 33 serves as the base of the control valve device 32 for the closed circuit and is attached to the swing frame 10. The manifold 33 is formed as a rectangular parallelepiped block body that is flat in the front-rear direction and extends in the left-right direction and the up-down direction. Therefore, the width direction of the manifold 33 is the left-right direction. The lower surface 33A of the manifold 33 is attached to the swing frame 10. Further, a filter 35 is attached to the upper surface 33B of the manifold 33.

[0038] Here, the manifold 33 has a front surface 33C and a rear surface 33D facing opposite sides in the front-rear direction. A control valve 34 for the closed circuit and a closed-circuit actuator-side pipe 47 are attached to the front surface 33C, which is the surface facing the front of the manifold 33. Specifically, the front surface 33C includes a valve attachment area 33E where a plurality of control valves 34 are attached at the central portion in the left-right direction, that is, at the position surrounded by the dashed-dotted line in FIG. 4. This valve attachment area 33E is arranged directly behind the left swing hydraulic motor 8. And a plurality of control valves 34 for the closed circuit are intensively attached to the valve attachment area 33E.

[0039] Further, the front surface 33C of the manifold 33 is provided with left and right pipe attachment areas 33F on the outer sides in the left - right direction than the valve attachment area 33E, that is, in the positions surrounded by the two - dotted - chain lines on both sides sandwiching the valve attachment area 33E in FIG. 4. In the pipe attachment areas 33F, pipe connection ports 33G serving as supply and discharge ports for pressure oil from the control valve 34 to each hydraulic actuator are provided. The separation distance between the left - hand pipe attachment area 33F and the right - hand pipe attachment area 33F is set to be equal to or greater than the dimension in the left - right direction of the left - hand swing hydraulic motor 8. And a plurality of actuator - side pipes 47 for a closed circuit are attached (connected) to the plurality of pipe connection ports 33G in the left and right pipe attachment areas 33F.

[0040] Furthermore, the manifold 33 is provided with a plurality of oil passages (none of which are shown in the figure) that communicate with a plurality of control valves 34 for a closed circuit attached to the valve attachment area 33E, a plurality of actuator - side pipes 47 for a closed circuit attached to the pipe attachment area 33F, and the like.

[0041] The plurality of control valves 34 for a closed circuit control the boom cylinder 24, arm cylinder 25, bucket cylinder 26 of the working device 20, the swing hydraulic motors 8, 9 of the swing device 6, and the like. The plurality of control valves 34 are attached to the front surface 33C and the rear surface 33D of the manifold 33. Specifically, the control valves 34 for a closed circuit attached to the front surface 33C of the manifold 33 are arranged in the valve attachment area 33E. Thus, by concentrating and arranging the plurality of control valves 34 at the central portion of the front surface 33C of the manifold 33, a space where the actuator - side pipes 47 for a closed circuit described later are not arranged (do not exist) in front of the plurality of control valves 34, that is, a first space 49 described later can be formed.

[0042] The filter 35 is attached to the upper surface 33B of the manifold 33. The filter 35 can prevent damage to sliding parts of hydraulic actuators, valves, etc. by capturing foreign matter mixed in the working oil.

[0043] Next, the open circuit system 36 is a hydraulic system for compensating for the excess or deficiency of hydraulic oil with respect to the closed circuit system 27. The open circuit system 37 is a hydraulic system for compensating for the excess or deficiency of hydraulic oil with respect to the closed circuit system 28. The open circuit system 38 is a hydraulic system for compensating for the excess or deficiency of hydraulic oil with respect to the closed circuit system 29. Further, the open circuit system 39 is a hydraulic system for compensating for the excess or deficiency of hydraulic oil with respect to the closed circuit system 30. Additionally, the open circuit systems 36 to 39 also supply hydraulic oil to the left and right traveling hydraulic motors 3 and 4.

[0044] The open circuit system 36 includes an open circuit hydraulic pump 40 driven by the engine 14, and an open circuit pump side pipe 46 (described later) that connects the open circuit hydraulic pump 40 and the closed circuit actuator side pipe 47, and an open circuit actuator side pipe 48. Also, a control valve 43 for the open circuit (described later) is provided in the open circuit system 36 between the open circuit pump side pipe 46 and the open circuit actuator side pipe 48.

[0045] Here, the configurations of the open circuit systems 37 to 39 are substantially the same as the configuration of the open circuit system 36. Therefore, the open circuit systems 37 to 39 are labeled with the same reference numerals used in the description of the open circuit system 36, and detailed descriptions thereof are omitted.

[0046] As shown in FIGS. 1 and 2, a plurality of, for example, four open circuit hydraulic pumps 40 that constitute the open circuit systems 36 to 39 are attached to the right side of the engine 14 (power transmission device 15) together with the closed circuit hydraulic pump 31. The four open circuit hydraulic pumps 40 are constituted by, for example, variable displacement axial piston hydraulic pumps, bent axis hydraulic pumps, radial piston hydraulic pumps, and the like.

[0047] The control valve device 41 for the open circuit is located in front of the engine 14 and is provided on the swing frame 10. Specifically, the control valve device 41 for the open circuit is arranged in a horizontal state extending in the left-right direction, closer to the hydraulic oil tank 18 than the control valve device 32 for the closed circuit, i.e., on the right side of the swing frame 10. Similar to the control valve device 32 for the closed circuit, the control valve device 41 for the open circuit includes a manifold 42, a control valve 43, and a filter 44, which will be described later.

[0048] The manifold 42, similar to the manifold 33, is formed as a rectangular parallelepiped block body that is flat in the front-rear direction and extends in the left-right and up-down directions. The manifold 42 has a lower surface 42A, an upper surface 42B, a front surface 42C, and a rear surface 42D, and the lower surface 42A is attached to the swing frame 10. Also, a filter 44 is attached to the upper surface 42B.

[0049] Here, as shown in FIG. 4, on the front surface 42C, which is the surface facing the front of the manifold 42, there is a valve mounting area 42E surrounded by a dashed line in the central part in the left-right direction, where a plurality of control valves 43 are mounted, and a piping mounting area 42F surrounded by a two-dot chain line in the outer part in the left-right direction outside the valve mounting area 42E, where piping connection ports 42G serving as supply and discharge ports for pressure oil from the plurality of control valves 43 to each hydraulic actuator are provided. A plurality of control valves 43 for the open circuit are mounted in the valve mounting area 42E, and a plurality of actuator-side pipes 48 for the open circuit connected to the plurality of piping connection ports 42G are mounted in the piping mounting area 42F. Also, the manifold 42 includes a plurality of oil passages (none of which are shown) that communicate with the plurality of control valves 43 for the open circuit, the actuator-side pipes 48 for the open circuit, etc.

[0050] A plurality of control valves 43 for the open circuit control the left traveling hydraulic motor 3, the right traveling hydraulic motor 4, etc. The plurality of control valves 43 are mounted on the valve mounting area 42E and the rear surface 42D of the front surface 42C of the manifold 42. In this way, by concentrating and arranging the plurality of control valves 43 at the central portion of the front surface 42C of the manifold 42, a space where the actuator side pipe 48 for the open circuit described later is not arranged, that is, a third space 51 described later can be formed in front of the plurality of control valves 43.

[0051] The filter 44 is mounted on the upper surface 42B of the manifold 42. Similar to the filter 35, the filter 44 can prevent damage to the sliding parts of the hydraulic actuator, valve, etc. by capturing foreign matter mixed in the hydraulic oil. The open circuit pump side pipe 46 described later is connected to the filter 44.

[0052] A plurality of closed circuit pump side pipes 45 connect the closed circuit hydraulic pump 31 and the filter 35 of the closed circuit control valve device 32. That is, as shown in FIGS. 2 and 3, each of the closed circuit pump-side pipes 45 extends forward from the closed circuit hydraulic pump 31, and is connected to the upper surface 33B of the manifold 33 from above the upper surface 33B of the manifold 33 via the filter 35. Also, a plurality of open circuit pump side pipes 46 connect the open circuit hydraulic pump 40 and the filter 44 of the open circuit control valve device 41. That is, as shown in FIGS. 2 and 3, each of the open circuit pump-side pipes 46 extends forward from the open circuit hydraulic pump 40, and is connected to the upper surface 42B of the manifold 42 from above the upper surface 42B of the manifold 42 via the filter 44.

[0053] A plurality of closed circuit actuator side pipes 47 connect the closed circuit control valve device 32 and the boom cylinder 24, arm cylinder 25, bucket cylinder 26 of the working device 20, and the swing hydraulic motors 8, 9 of the swing device 6. One end of the plurality of closed circuit actuator side pipes 47 is mounted on the front surface 33C of the manifold 33, and the other end extending forward from the front surface 33C is connected to the cylinders 24 to 26 of the working device 20 and the swing hydraulic motors 8, 9 of the swing device 6 via a joint block 52 described later.

[0054] Here, the plurality of actuator-side pipes 47 for the closed circuits are distributed and attached to the left and right pipe attachment areas 33F provided on the front surface 33C of the manifold 33. In this case, since the left and right pipe attachment areas 33F are arranged at an interval equal to or greater than the horizontal dimension of the left swing hydraulic motor 8, the plurality of actuator-side pipes 47 for the closed circuits extending forward from the front surface 33C are routed avoiding the left swing hydraulic motor 8. The actuator-side pipe 47 for the closed circuit extending forward from the left pipe attachment area 33F passes to the left side of the left swing hydraulic motor 8, and the actuator-side pipe 47 for the closed circuit extending forward from the right pipe attachment area 33F extends forward passing between the left swing hydraulic motor 8 and the right swing hydraulic motor 9.

[0055] In other words, the plurality of actuator-side pipes 47 for the closed circuits are routed so as not to overlap the left swing hydraulic motor 8 in plan view. As a result, the plurality of actuator-side pipes 47 for the closed circuits do not interfere with the removal and installation work of the left swing hydraulic motor 8. That is, a first space 49 can be formed between the actuator-side pipes 47 for the closed circuits distributed left and right on the front side of the manifold 33.

[0056] The plurality of actuator-side pipes 48 for the open circuits connect the open circuit control valve device 41 and the left travel hydraulic motor 3, the right travel hydraulic motor 4, etc. of the lower traveling body 2. One end of the plurality of actuator-side pipes 48 for the open circuits is attached to the front surface 42C of the manifold 42, and the other end extending forward from the front surface 42C is connected to the center joint 17 (travel hydraulic motors 3, 4), etc. via the joint block 52.

[0057] The plurality of open - circuit actuator - side pipes 48 are distributed to the left and right pipe - mounting areas 42F provided on the front surface 42C of the manifold 42. The plurality of open - circuit actuator - side pipes 48 mounted on the front surface 42C in the left - hand pipe - mounting area 42F are bent to the right and then extend forward through the right - hand side of the right - hand slewing hydraulic motor 9 so as not to overlap the right - hand slewing hydraulic motor 9 in plan view. Thus, the plurality of open - circuit actuator - side pipes 48 do not interfere with the removal and installation work of the right - hand slewing hydraulic motor 9. That is, a second space 50 can be formed between the right - hand closed - circuit actuator - side pipe 47 and the left - hand open - circuit actuator - side pipe 48 on the front side of the manifold 42.

[0058] Furthermore, the open - circuit actuator - side pipe 48 mounted on the front surface 42C in the right - hand pipe - mounting area 42F extends straight forward and then bends to the left. Thereby, a third space 51 can be formed between the left - hand open - circuit actuator - side pipe 48 and the right - hand open - circuit actuator - side pipe 48 on the front side of the manifold 42.

[0059] The first space 49 is provided in front of the closed - circuit control valve device 32. The first space 49 is a space where the removal and installation work of the left - hand slewing hydraulic motor 8 and the maintenance of the control valve 34 of the closed - circuit control valve device 32 can be performed. Specifically, the first space 49 divides the plurality of closed - circuit actuator - side pipes 47 into a left - hand closed - circuit actuator - side pipe 47 extending forward from the left - hand pipe - mounting area 33F of the manifold 33 and a right - hand closed - circuit actuator - side pipe 47 extending forward from the right - hand pipe - mounting area 33F of the manifold 33. Thus, the first space 49 is formed as a space surrounded by the closed - circuit control valve device 32, the left - hand closed - circuit actuator - side pipe 47, and the right - hand closed - circuit actuator - side pipe 47.

[0060] In this case, the space where the detachment operation of the left swing hydraulic motor 8 can be performed is a space where a tool can be applied to the bolts (not shown) fixing the swing hydraulic motor 8 to the speed reducer, and the swing hydraulic motor 8 can be lifted up.

[0061] The second space 50 is provided on the front side to the left of the open circuit control valve device 41. The second space 50 is a space where the detachment operation of the right swing hydraulic motor 9 can be performed. Specifically, the second space 50 is surrounded by the left open circuit actuator side pipe 48 that bends forward from the pipe attachment area 42F on the left side of the manifold 42 and the right closed circuit actuator side pipe 47 described above. The space where the detachment operation of the right swing hydraulic motor 9 can be performed is a space where a tool can be applied to the bolts (not shown) fixing the swing hydraulic motor 9 to the speed reducer, and the swing hydraulic motor 9 can be lifted up, similar to the first space 49.

[0062] The third space 51 is located on the right side of the second space 50 and provided on the front side of the open circuit control valve device 41. The third space 51 is a space where maintenance of the control valve 43 of the open circuit control valve device 41 can be performed. Specifically, the third space 51 divides the plurality of open circuit actuator side pipes 48 into the left open circuit actuator side pipe 48 extending forward from the pipe attachment area 42F on the left side of the manifold 42 and the right open circuit actuator side pipe 48 extending forward from the pipe attachment area 42F on the right side of the manifold 42. Thereby, the third space 51 is formed as a space surrounded by the open circuit control valve device 41, the left open circuit actuator side pipe 48, and the right open circuit actuator side pipe 48.

[0063] The joint block 52 is provided, for example, in the vicinity of the base end portion of the boom 21 of the working device 20. The joint block 52 constitutes a joint that collectively fixes the connection portions of the plurality of closed circuit actuator side pipes 47 and the connection portions of the plurality of open circuit actuator side pipes 48.

[0064] One tank-side pipe 53 for the closed circuit connects the control valve device 32 for the closed circuit and the hydraulic oil tank 18. The tank-side pipe 53 for the closed circuit is a pipe for returning the hydraulic oil to the hydraulic oil tank 18 and is routed through the upper side of the control valve device 41 for the open circuit. Thereby, the tank-side pipe 53 for the closed circuit does not get in the way when working in the third space 51.

[0065] The tank-side pipe 54 for the open circuit connects the control valve device 41 for the open circuit and the hydraulic oil tank 18. The tank-side pipes 54 for the open circuit are pipes for returning the hydraulic oil to the hydraulic oil tank 18 and a plurality of them are provided.

[0066] The controller 55 is connected to the operation device 13, a plurality of control valves 34 of the control valve device 32 for the closed circuit, and the control valve 43 of the control valve device 41 for the open circuit via signal lines. The controller 55 switches the control valves 34, 43 based on signals from the operation device 13.

[0067] The hydraulic excavator 1 according to the present embodiment has the configuration as described above, and next, its operation will be described.

[0068] The operator who gets on the cab 11 starts the engine 14 and drives the hydraulic pump 31 for the closed circuit and the hydraulic pump 40 for the open circuit. In this state, by operating the left and right travel levers and pedals 13C, 13D, the lower travel body 2 can be moved forward or backward. On the other hand, by operating the left operation lever 13A and the right operation lever 13B for work, the work device 20 can be rotated to perform earth and sand excavation work and the like.

[0069] Thus, in the present embodiment, the control valve device 32 for the closed circuit is located on the front surface 33C which is the surface facing the front of the manifold 33, and includes a plurality of control valves 34 for the closed circuit, and a plurality of pipe connection ports 33G located on the front surface 33C of the manifold 33 to which a plurality of actuator-side pipes 47 for the closed circuit are connected. Further, the front surface 33C of the manifold 33 is disposed behind the left swing hydraulic motor 8 so as to face the left swing hydraulic motor 8. The front surface 33C of the manifold 33 includes a valve mounting area 33E provided at the center in the left-right direction and to which a plurality of control valves 34 are attached, and a pipe mounting area 33F provided at the outer side in the left-right direction than the valve mounting area 33E and to which a plurality of actuator-side pipes 47 for the closed circuit are attached to the pipe connection ports 33G.

[0070] On the other hand, the control valve device 41 for the open circuit is located on the front surface 42C which is the surface facing the front of the manifold 42, and includes a plurality of control valves 43 for the open circuit, and a plurality of pipe connection ports 42G located on the front surface 42C of the manifold 42 to which a plurality of actuator-side pipes 48 for the open circuit are connected. Further, the front surface 42C of the manifold 42 is disposed behind the right swing hydraulic motor 9 so as to face the right swing hydraulic motor 9. The front surface 42C of the manifold 42 includes a valve mounting area 42E provided at the center in the left-right direction and to which a plurality of control valves 43 are attached, and a pipe mounting area 42F provided at the outer side in the left-right direction than the valve mounting area 42E and to which a plurality of actuator-side pipes 48 for the open circuit are attached to the pipe connection ports 42G.

[0071] Therefore, the actuator-side pipe 47 for the closed circuit extending forward from the left pipe mounting area 33F of the manifold 33 passes by the left side of the left swing hydraulic motor 8, and the actuator-side pipe 47 for the closed circuit extending forward from the right pipe mounting area 33F of the manifold 33 passes by the right side of the left swing hydraulic motor 8. Thereby, the plurality of actuator-side pipes 47 for the closed circuit can be routed while avoiding the left swing hydraulic motor 8 in plan view.

[0072] In addition, the open - circuit actuator - side pipe 48 extending forward from the pipe - mounting area 42F on the left side of the manifold 42 passes by the right side of the right - hand swing hydraulic motor 9. As a result, a plurality of open - circuit actuator - side pipes 48 can be routed while avoiding the right - hand swing hydraulic motor 9 in plan view.

[0073] Furthermore, the open - circuit actuator - side pipe 48 extending forward from the pipe - mounting area 42F on the right side of the manifold 42 has a lateral spacing from the open - circuit actuator - side pipe 48 extending forward from the pipe - mounting area 42F on the left side of the manifold 42. As a result, a plurality of open - circuit actuator - side pipes 48 can be routed while avoiding the front side of the control valve 43 for the open circuit.

[0074] As a result, it is possible to secure a space for attaching and detaching each control valve 34, 43 attached to the control valve devices 32, 41, the swing hydraulic motors 8, 9 etc. arranged close to the control valve devices 32, 41, and performing maintenance on them. As a result, since the operation of removing a plurality of actuator - side pipes 47, 48 can be omitted, the workability of attaching and detaching the control valves 34, 43, the swing hydraulic motors 8, 9 etc., and maintenance and other operations can be improved.

[0075] A plurality of closed - circuit actuator - side pipes 47 are routed from the pipe - mounting area 33F on the front surface 33C of the manifold 33, bypassing the space above the left - hand swing hydraulic motor 8 and facing forward so that a work space is secured above the left - hand swing hydraulic motor 8 and in front of the valve - mounting area 33E. As a result, a work space can be secured above the left - hand swing hydraulic motor 8 and in front of the valve - mounting area 33E. On the other hand, a plurality of open - circuit actuator - side pipes 48 are routed from the pipe - mounting area 42F on the front surface 42C of the manifold 42, bypassing the space above the right - hand swing hydraulic motor 9 and facing forward so that a work space is secured above the right - hand swing hydraulic motor 9 and in front of the valve - mounting area 42E. As a result, a work space can be secured above the right - hand swing hydraulic motor 9 and in front of the valve - mounting area 42E.

[0076] A closed-circuit system 27 to 30 for supplying and discharging hydraulic oil between a hydraulic pump 31 for a closed circuit and hydraulic actuators including a boom cylinder 24, an arm cylinder 25, a bucket cylinder 26 of a working device 20, and swing hydraulic motors 8 and 9 of a swing device 6, and an open-circuit system 36 to 39 for supplying the hydraulic oil in a hydraulic oil tank 18 provided on a swing frame 10 from an open-circuit hydraulic pump 40 to each of the cylinders 24 to 26 of the working device 20 and the swing hydraulic motors 8 and 9 of the swing device 6 and to traveling hydraulic motors 3 and 4 of a lower traveling body 2 different therefrom are provided. Further, the control valve device includes a control valve device 32 for a closed circuit connected to the closed-circuit system 27 to 30 and a control valve device 41 for an open circuit connected to the open-circuit system 36 to 39. Moreover, the control valve device 41 for an open circuit is arranged at a position closer to the hydraulic oil tank 18 than the control valve device 32 for a closed circuit.

[0077] Here, the control valve device 32 for a closed circuit is connected to the hydraulic oil tank 18 by a single closed-circuit tank-side pipe 53. On the other hand, the control valve device 41 for an open circuit is connected to the hydraulic oil tank 18 by a plurality of open-circuit tank-side pipes 54. Therefore, by arranging the control valve device 41 for an open circuit, to which the number of the open-circuit tank-side pipes 54 connected to the hydraulic oil tank 18 is large, at a position close to the hydraulic oil tank 18, the total length dimension of the closed-circuit tank-side pipe 53 and the plurality of open-circuit tank-side pipes 54 can be shortened. Thereby, the tank-side pipes 53 and 54 can simplify the pipe layout and can reduce the cost.

[0078] The plurality of actuator-side pipes 47 for the closed circuit are routed forward from the pipe attachment area 33F on the front surface 33C of the manifold 33 of the closed-circuit control valve device 32, bypassing the space in front of the valve attachment area 33E and above the left swing hydraulic motor 8, and are routed forward so that a first space 49 where the detachment work of the left swing hydraulic motor 8 and the maintenance of the control valve 34 of the closed-circuit control valve device 32 can be performed is provided in front of the closed-circuit control valve device 32, and a second space 50 where the detachment work of the right swing hydraulic motor 9 can be performed and a third space 51 where the maintenance of the control valve 43 of the open-circuit control valve device 41 can be performed are provided in front of the open-circuit control valve device 41. Similarly, they are routed forward from the pipe attachment area 42F on the front surface 42C of the manifold 42 of the open-circuit control valve device 41, bypassing the space in front of the valve attachment area 42E and above the right swing hydraulic motor 9. As a result, in the first space 49, the detachment work of the left swing hydraulic motor 8 and the maintenance of the control valve 34 of the closed-circuit control valve device 32 can be performed. Also, in the second space 50, the detachment work of the right swing hydraulic motor 9 can be performed. Further, in the third space 51, the maintenance of the control valve 43 of the open-circuit control valve device 41 can be performed.

[0079] A closed-circuit tank-side pipe 53 that connects the closed-circuit control valve device 32 and the hydraulic oil tank 18 is provided. This closed-circuit tank-side pipe 53 is routed through the upper side of the open-circuit control valve device 41. Thereby, since the closed-circuit tank-side pipe 53 does not get in the way when working in the third space 51, the workability when performing the maintenance of the control valve 43 of the open-circuit control valve device 41 in the third space 51 can be improved.

[0080] In the embodiment, the case where the control valve device 32 for the closed circuit and the control valve device 41 for the open circuit are provided side by side in the left - right direction on the slewing frame 10 is illustrated. However, the present invention is not limited to this configuration. For example, a single common manifold may be provided, and the control valve of the control valve device for the closed circuit and the control valve of the control valve device for the open circuit may be attached to this common manifold. Also, a configuration in which three or more control valve devices are provided may be adopted.

[0081] In the embodiment, the hydraulic excavator 1 equipped with the backhoe - type working device 20 as a construction machine has been described as an example. However, the present invention is not limited to this, and it can be widely applied to other construction machines such as hydraulic excavators equipped with a loading - shovel - type working device.

Explanation of Signs

[0082] 1 Hydraulic excavator (construction machine) 2 Lower traveling body 3 Left - hand traveling hydraulic motor (hydraulic actuator) 4 Right - hand traveling hydraulic motor (hydraulic actuator) 5 Upper slewing body 6 Slewing device 8 Left - hand slewing hydraulic motor (hydraulic actuator) 9 Right - hand slewing hydraulic motor (hydraulic actuator) 10 Slewing frame 14 Engine (prime mover) 18 Hydraulic oil tank 20 Working device 24 Boom cylinder (hydraulic actuator) 25 Arm cylinder (hydraulic actuator) 26 Bucket cylinder (hydraulic actuator) 27 - 30 Closed - circuit system 31 Hydraulic pump for closed - circuit 32 Control valve device for closed - circuit (control valve device) 33, 42 Manifold 33C, 42C Front surface 33E, 42E Valve mounting area 33F and 42F Pipe Installation Area 33G and 42G Pipe Connection Ports 34 and 43 Control Valves 36 - 39 Open - Circuit System 40 Open - Circuit Hydraulic Pump 41 Open - Circuit Control Valve Device (Control Valve Device) 45 Closed - Circuit Pump - Side Pipe 46 Open - Circuit Pump - Side Pipe 47 Closed - Circuit Actuator - Side Pipe 48 Open - Circuit Actuator - Side Pipe 49 First Space 50 Second Space 51 Third Space 53 Closed - Circuit Tank - Side Pipe 54 Open - Circuit Tank - Side Pipe

Claims

Claims 1. A construction machine comprising: a lower traveling body having crawlers rotated by a traveling hydraulic motor and capable of self-propelling; an upper slewing body rotatably provided on the lower traveling body via a slewing device; a working device provided at the front of the upper slewing body and including a boom, an arm, and a bucket each rotated by a boom cylinder, an arm cylinder, and a bucket cylinder each composed of a hydraulic cylinder; and a hydraulic system for driving the lower traveling body, the upper slewing body, and the working device. The slewing device includes: a slewing ring that rotatably supports the upper slewing body on the lower traveling body; a slewing hydraulic motor provided on the upper slewing body and configured to slewingly operate the upper slewing body along the slewing ring on the lower traveling body. The hydraulic system includes: a closed circuit system that uses the boom cylinder, the arm cylinder, the bucket cylinder, and the slewing hydraulic motor as hydraulic actuators and supplies and discharges hydraulic oil to and from each of the hydraulic actuators; an open circuit system that supplies hydraulic oil to the closed circuit system and uses the traveling hydraulic motor as a hydraulic actuator to supply hydraulic oil from an oil tank to each of the hydraulic actuators. The upper slewing body includes: a slewing frame rotatably supported on the lower traveling body via the slewing ring; a prime mover provided on the rear side of the slewing frame; a plurality of hydraulic pumps for closed circuits and a plurality of hydraulic pumps for open circuits respectively included in the closed circuit system and the open circuit system and driven by the prime mover; a control valve device having a plurality of control valves attached to a rectangular parallelepiped-shaped manifold provided on the slewing frame and positioned in front of the prime mover, the plurality of hydraulic pumps for closed circuits, and the plurality of hydraulic pumps for open circuits; a plurality of pump-side pipes connecting the plurality of hydraulic pumps for closed circuits, the plurality of hydraulic pumps for open circuits, and the control valve device; a plurality of actuator-side pipes connecting the control valve device to the boom cylinder, the arm cylinder, the bucket cylinder of the working device, the slewing hydraulic motor of the slewing device, and the traveling hydraulic motor. The control valve device includes a plurality of control valves located on the front surface facing the front of the manifold, and a plurality of pipe connection ports located on the front surface of the manifold to which the plurality of actuator-side pipes are connected. The front surface of the manifold is arranged on the rear side of the swing hydraulic motor so as to face the swing hydraulic motor. A valve mounting area where the plurality of control valves are mounted is provided at the center in the left-right direction on the front surface of the manifold. On the outer sides in the left-right direction of the valve mounting area across the valve mounting area on the front surface of the manifold, pipe connection ports are respectively provided, and a pipe mounting area where the plurality of actuator-side pipes extending toward the front of the manifold are mounted is provided. A construction machine characterized in that a plurality of pump-side pipes are connected to the upper surface of the manifold from above.

2. In the construction machine according to claim 1, The plurality of actuator-side pipes are routed from the pipe mounting area on the front surface of the manifold so as to bypass the space above the swing hydraulic motor and be routed forward so that a working space is secured above the swing hydraulic motor and in front of the valve mounting area. A construction machine characterized by this.

3. In the construction machine according to claim 1, The control valve device consists of a closed-circuit control valve device connected to the closed-circuit system and an open-circuit control valve device connected to the open-circuit system. A construction machine characterized in that the open-circuit control valve device is arranged at a position closer to the hydraulic oil tank than the closed-circuit control valve device.

4. In the construction machine according to claim 3, The plurality of actuator-side pipes are On the front side of the closed-circuit control valve device, a first space is provided so that the attachment / detachment work of the swing hydraulic motor and the maintenance of the control valve of the closed-circuit control valve device can be performed. And on the front side of the open-circuit control valve device, a second space where the attachment / detachment work of the swing hydraulic motor can be performed and a third space where the maintenance of the control valve of the open-circuit control valve device can be performed are provided. A construction machine, characterized in that it is routed forward by bypassing a space above the valve mounting area and in front of the swivel hydraulic motor from the piping mounting area on the front surface of the manifold of the closed-circuit control valve device and the open-circuit control valve device.

5. In the construction machine according to claim 3, a closed-circuit tank-side pipe connecting the closed-circuit control valve device and the hydraulic oil tank is provided, the closed-circuit tank-side pipe is routed through the upper side of the open-circuit control valve device.

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