Pump device and hydraulic circuit system for construction machinery

Abstract

To eliminate a hydraulic hose for connecting a plurality of discharge ports to a plurality of switching valves in a pump device provided with two hydraulic pumps capable of independently controlling flow rates of pressure oil discharged from the plurality of discharge ports and a parallel pump in which the plurality of switching valves are arranged.SOLUTION: A parallel pump 30 and a manifold block 40 including four pump elements 11a-11d, 12a-12d capable of independently controlling the flow rate of pressure oil discharged from discharge ports 45a-45d, 46a-46d and mounted with switching valves 41a-41d, 42a-42d are connected to a block surface 13S of a port block 13 by a bolt or the like so that first inlet ports 65a-65d are aligned with the first discharge ports 45a-45d formed in the block surface 13S of the port block 13, and second inlet ports 66a-66d are aligned with the second discharge ports 46a-46d formed in the block surface 13S of the port block 13.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a pump device and a hydraulic circuit system for a hydraulic circuit system mounted on a construction machine such as a hydraulic excavator, and in particular to a pump device and a hydraulic circuit system for a construction machine equipped with a plurality of hydraulic pumps capable of independently controlling the flow rate of each of a plurality of discharge ports. [Background technology]

[0002] Patent Document 1 describes a parallel pump in which two pumps, a drive pump and a driven pump, are arranged in parallel as a pump device used in the hydraulic circuit system of construction machinery such as hydraulic excavators. In this parallel pump, the drive pump and the driven pump share a common head casing, and a discharge port for the drive pump and a discharge port for the driven pump are formed in this head casing, so that the discharge flow rates of the drive pump and the driven pump can be extracted.

[0003] Patent Document 2 describes a hydraulic circuit system equipped with a hydraulic pump containing four pump elements capable of independently controlling the flow rate of pressurized oil discharged from four discharge ports. In this hydraulic circuit system, the four discharge ports of the hydraulic pump are connected to 16 changeover valves via four hydraulic hoses, and the 16 changeover valves are further connected to four load port oil passages, and by switching the 16 changeover valves, the number of discharge ports according to the demand of the actuator is connected to the load port oil passages, making it possible to supply the actuator with a flow rate according to the demand. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6134930 [Patent Document 2] US 2019 / 0211849A1 Summary of the Invention [Problem to be solved by the invention]

[0005] A two-pump, two-valve group system using two hydraulic pumps and a control valve including two valve groups is widely used as a hydraulic circuit system for construction machines that drive multiple actuators, such as hydraulic excavators. When the parallel pump described in Patent Document 1 is used as a hydraulic source for such a hydraulic circuit system, the hydraulic source is composed of one pump (parallel pump), which has the advantage of making the hydraulic source compact.

[0006] By arranging two hydraulic pumps described in Patent Document 2 to form a parallel pump as in Patent Document 1, the hydraulic source can be formed with a single pump (parallel pump), similar to the parallel pump in Patent Document 1, making the hydraulic source compact.

[0007] However, in the hydraulic circuit system described in Patent Document 2, in order to extract four discharge flow rates from the four discharge ports of one hydraulic pump, four hydraulic hoses are used to connect the four discharge ports to multiple switching valves. Therefore, when two hydraulic pumps are used, the number of switching valves and hydraulic hoses doubles, and it becomes necessary to use eight hydraulic hoses to connect the eight discharge ports to multiple switching valves. As a result, although the hydraulic pump body becomes compact, a large number of hydraulic hoses are required to connect the multiple discharge ports of the hydraulic pump to the multiple switching valves, which causes a problem of a complex hose layout and reduced mountability on construction machinery.

[0008] The object of the present invention is to provide a pump device and hydraulic circuit system for construction machinery which has a pump arrangement section formed by arranging two hydraulic pumps capable of independently controlling the flow rate of pressurized oil discharged from multiple discharge ports, and which, when used as a hydraulic source for a hydraulic circuit system, eliminates the hydraulic hoses connecting the multiple discharge ports to multiple switching valves, thereby improving mountability. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a pump device for a construction machine equipped with a pump arrangement having a first hydraulic pump and a second hydraulic pump connected via a gear box to a pump shaft driven and rotated by a prime mover, the first hydraulic pump being configured to form a plurality of first pump elements capable of independently controlling the flow of pressurized oil discharged from a plurality of first discharge ports, the second hydraulic pump being configured to form a plurality of second pump elements capable of independently controlling the flow of pressurized oil discharged from a plurality of second discharge ports, the first hydraulic pump being configured to form a port block in which the plurality of first discharge ports and the plurality of second discharge ports are formed and which is configured as a shared component of the first hydraulic pump and the second hydraulic pump, a plurality of first inlet ports and a plurality of second inlet ports into which pressurized oil flows from the plurality of first discharge ports and the plurality of second discharge ports of the port block, respectively, and a plurality of hydraulic hoses connected to a control valve. the port block further comprises a manifold block incorporating a plurality of first switching valves for switching the flow direction of the pressurized oil flowing in from the plurality of first inlet ports so as to guide the pressurized oil flowing in from the plurality of second inlet ports to any one of the plurality of service ports, and a plurality of first switching valves for switching the flow direction of the pressurized oil flowing in from the plurality of second inlet ports so as to guide the pressurized oil flowing in from the plurality of second inlet ports to any one of the plurality of service ports, the plurality of first discharge ports and the plurality of second discharge ports of the port block are formed to open to a side portion of the port block, and the manifold block is coupled to the side portion of the port block so that the plurality of first discharge ports of the port block are aligned with the plurality of first inlet ports and the plurality of second discharge ports of the port block are aligned with the plurality of second inlet ports.

[0010] Furthermore, in order to achieve the above object, the present invention provides a hydraulic circuit system for a construction machine comprising a prime mover, a pump device driven by the prime mover, a plurality of actuators driven by pressurized oil discharged from the pump device, and a plurality of directional control valves for controlling the flow of pressurized oil supplied from the pump device to the plurality of actuators, the pump device comprising a pump arrangement section having a first hydraulic pump and a second hydraulic pump connected via a gear box to a pump shaft driven and rotated by the prime mover, the first hydraulic pump being configured to form a plurality of first pump elements capable of independently controlling the flow of pressurized oil discharged from a plurality of first discharge ports, the second hydraulic pump being configured to form a plurality of second pump elements capable of independently controlling the flow of pressurized oil discharged from a plurality of second discharge ports, a port block in which the plurality of first discharge ports and the plurality of second discharge ports are formed and which is configured as a shared component of the first hydraulic pump and the second hydraulic pump, and a plurality of first inlet ports and a plurality of second inlet ports into which pressurized oil flows from the plurality of first discharge ports and the plurality of second discharge ports of the port block, respectively. the manifold block is further provided with an inlet port and a plurality of service ports connected to a control valve via a plurality of hydraulic hoses, and a plurality of first switching valves for switching the flow direction of the pressurized oil flowing in from the plurality of first inlet ports so as to guide the pressurized oil flowing in from the plurality of second inlet ports to any one of the plurality of service ports, and a plurality of second switching valves for switching the flow direction of the pressurized oil flowing in from the plurality of second inlet ports so as to guide the pressurized oil flowing in from the plurality of second inlet ports to any one of the plurality of service ports, the plurality of first discharge ports and the plurality of second discharge ports of the port block are formed to open to a side portion of the port block, the manifold block is coupled to the side portion of the port block so that the plurality of first inlet ports are aligned with the plurality of first discharge ports of the port block and the plurality of second inlet ports are aligned with the plurality of second discharge ports of the port block, and the plurality of service ports of the manifold block are connected via a plurality of piping to a control valve having the plurality of directional control valves housed within a valve housing.

[0011] In this way, by forming the multiple first discharge ports and multiple second discharge ports of the port block to open to the side of the port block, and by connecting the manifold block to the side of the port block so that the multiple first discharge ports of the port block are aligned with the multiple first inlet ports of the manifold block and the multiple second discharge ports of the port block are aligned with the multiple second inlet ports of the manifold block, a pump arrangement is formed by arranging two hydraulic pumps that can independently control the flow rate of pressurized oil discharged from the multiple discharge ports, and when used as a hydraulic source for a hydraulic circuit system, it is possible to eliminate all of the numerous hydraulic hoses connecting the multiple first and second discharge ports of the port block to the multiple first and second inlet ports of the manifold block (inlet ports of the multiple first and second switching valves), and to reduce the size of the pump device including the manifold block, thereby improving mountability on construction machinery. Effect of the Invention

[0012] According to the present invention, a pump arrangement is formed by arranging two hydraulic pumps capable of independently controlling the flow rate of pressurized oil discharged from multiple discharge ports, and when used as a hydraulic source for a hydraulic circuit system, it is possible to eliminate all of the numerous hydraulic hoses connecting the multiple discharge ports to the multiple switching valves, and to miniaturize the pump device including the manifold block, thereby improving the ease of installation on construction machinery. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram showing a hydraulic excavator as a representative example of a construction machine equipped with a pump device according to the present invention. [Diagram 2] 1 is an external view of a pump device according to a first embodiment of the present invention, as viewed from above. [Diagram 3] 3 is a horizontal cross-sectional view taken along a pump shaft of the pump device shown in FIG. 2. [Figure 4] 6 is a vertical cross-sectional view of the pump device taken along line VI-VI in FIG. 2. [Diagram 5]FIG. 7 is a vertical cross-sectional view of the pump device taken along line VII-VII in FIG. [Figure 6] 8 is a vertical cross-sectional view of the pump device taken along line VIII-VIII in FIG. 3. [Figure 7] FIG. 2 is a top view of the port block. [Figure 8] FIG. 2 is a top view of the manifold block. [Figure 9] FIG. 4 is a bottom view of the manifold block. [Figure 10] FIG. 4 is a horizontal cross-sectional view of the manifold block taken along line XII-XII of FIG. [Figure 11] 13 is a vertical cross-sectional view of the manifold block taken along line XIII-XIII in FIG. 8. [Figure 12] 13 is a diagram showing a connection state between a first inlet port and two internal passages when the first switching valve is in an initial position. FIG. [Figure 13] 13 is a diagram showing a connection state between the first inlet port and two internal passages when the first switching valve is switched from the initial position to the non-initial position. FIG. [Figure 14] FIG. 4 is a layout diagram showing a state in which the pump device is mounted on an upper rotating body. [Figure 15] 1 is a diagram showing an example of a hydraulic circuit system configured using a pump device according to a first embodiment of the present invention. [Figure 16] FIG. 11 is a top view of a manifold block in a pump device according to a second embodiment of the present invention. [Figure 17] A longitudinal cross-sectional view of the hold block taken along line XVII-XVII in Figure 16, similar to Figure 12, showing the connection state between the first inlet port and two internal passages when the second switching valve is in the initial position. [Figure 18] 14 is a view similar to FIG. 13, showing the connection state between the first inlet port and the two internal passages when the second switching valve is switched from the initial position to the non-initial position. FIG. [Figure 19] 15 is a layout diagram similar to FIG. 14, showing the pump device of this embodiment mounted on an upper rotating body. [Figure 20]FIG. 2 is a schematic diagram showing a part of an electronically controlled hydraulic pump equipped with a pump element, illustrating the operating principle of the first and second hydraulic pumps. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0015] <First embodiment> A first embodiment of the present invention will be described.

[0016] ~Construction machinery~ FIG. 1 is a diagram showing a hydraulic excavator, which is a representative example of construction machinery equipped with the pump device of the present invention.

[0017] The hydraulic excavator 100 shown in Figure 1 is configured such that an upper rotating body 102 equipped with a cab 102a for an operator is mounted via a rotating device 107 on a lower running body 101 equipped with left and right crawler-type running devices 108a, 108b.

[0018] A boom 104 of a front work machine 103 is connected to the front of the upper rotating body 102, and the boom 104 is driven by a boom cylinder 104a, which is a single-rod hydraulic cylinder. An arm 105 is connected to the tip of the boom 104, and the arm 105 is driven by an arm cylinder 105a. A bucket 106 is connected to the tip of the arm 105, and the bucket 106 is driven by a bucket cylinder 106a. The rotating device 107 is driven by a rotating motor 107a, and the traveling devices 108a, 108b are driven by left and right traveling motors 108c, 108d.

[0019] ~Pump equipment~ [External appearance of pump unit] FIG. 2 is an external view of the pump device according to the first embodiment of the present invention, seen from above.

[0020] The pump device 10 comprises a pump shaft 14 which is connected to the output shaft of the engine 1 (see Figure 14) which is the prime mover and which is driven to rotate by the engine 1, a pump arrangement section 30 which is connected to the pump shaft 14 via a gear box 47, and a manifold block 40 which is attached to the upper surface portion of the pump arrangement section 30 on the opposite side to the pump shaft 14.

[0021] In this embodiment, the pump arrangement unit 30 is a parallel pump, and includes a first hydraulic pump 11 and a second hydraulic pump 12 (see FIG. 3) in which first and second driven shafts 14a, 14b (described later) are arranged parallel to each other.

[0022] The pump arrangement section 30 may be structured such that the first driven shaft 14a of the first hydraulic pump 11 is arranged at an inclination inward toward the gear box 47 relative to the pump shaft 14, and the second driven shaft 14b of the second hydraulic pump 12 is arranged at an inclination inward toward the gear box 47 relative to the pump shaft 14.

[0023] The first hydraulic pump 11 and the second hydraulic pump 12 have a common pump casing 48, and the parallel pump 30 further has a port block 13 (see FIG. 3) connected to a side surface of the pump casing 48. The manifold block 40 has four first switching valves 41a to 41d and four second switching valves 42a to 42d mounted thereon, and first and second service ports 43, 44 are formed on an upper surface 40d of the manifold block 40.

[0024] In addition, the first and second hydraulic pumps 11, 12 each have four first discharge ports 45a to 45d which are two or more first discharge ports and four second discharge ports 46a to 46d which are two or more second discharge ports, the first hydraulic pump 11 contains four first pump elements 11a to 11d (see Figure 15) which are two or more first pump elements that can independently control the flow rate of pressurized oil discharged from the four first discharge ports 45a to 45d, and the second hydraulic pump 12 contains four second pump elements 12a to 12d (see Figure 15) which are two or more second pump elements that can independently control the flow rate of pressurized oil discharged from the four second discharge ports 46a to 46d.

[0025] [Operation principle of the first and second hydraulic pumps] The d1 pump elements 11a-11d and the second pump elements 12a-12d of the first and second hydraulic pumps 11, 12 are each composed of a plurality of cylinder working chambers and solenoid valves that vary the net volume (capacity), and the discharge flow rates of the first pump elements 11a-11d and the second pump elements 12a-12d are controlled by switching the solenoid valves and changing the net volume of the cylinder working chambers based on commands output from the controller 57 and the pump controllers 58, 59. A hydraulic pump incorporating such pump elements is sometimes called a digital pump.

[0026] The details of the operating principle of the first hydraulic pump 11 and the second hydraulic pump 12 will be explained using Fig. 20. Fig. 20 is a schematic diagram showing a part of an electronically controlled hydraulic pump 200 that contains multiple pump elements, and the first and second hydraulic pumps 11, 12 each have the same configuration as the hydraulic pump 200.

[0027] The hydraulic pump 200 has a pump shaft 204 and at least three cylinder working chambers (hereinafter simply referred to as working chambers) 202 whose volumes change periodically as the pump shaft 204 rotates.

[0028] The hydraulic pump 200 also has a low pressure valve 209 that controls the flow of pressurized oil between a low pressure manifold 201 connected to a tank port 216 and the working chamber 202, and a high pressure valve 212 that controls the flow of pressurized oil between a high pressure manifold 213 connected to a discharge port 214 and the working chamber 202.

[0029] The hydraulic pump 200 forms a plurality of pump elements by means of working chambers 202, and each pump element has one or more working chambers 202 (typically multiple working chambers 202) and is connected to the aforementioned high-pressure manifold 213 which is common to the multiple working chambers 202 of each pump element.

[0030] The controller 207 corresponds to the pump controllers 58 and 59 shown in Figure 2, and actively controls at least the low-pressure valve in phase correlation with the volume cycle of the working chamber 202, thereby determining whether each working chamber 202 will perform an active cycle in which a net volume of the working chamber 202 is formed between the low-pressure manifold 210 and the high-pressure manifold 213, or an inactive cycle in which a net volume of the working chamber 202 is not formed between the low-pressure manifold 210 and the high-pressure manifold 213, and thereby controlling the net volume of the working chamber 202 of each pump element leading to each discharge port 214 via each high-pressure manifold 213 according to the required flow rate.

[0031] The hydraulic pump 200 includes a plurality of cylinders 201 that form a plurality of working chambers 202 by their inner circumferential surfaces, and a plurality of pistons 203 that are driven by an eccentric cam 205 provided on a pump shaft 204 and reciprocate within the cylinders 201 to periodically change the volume of the working chambers 202 of the cylinders 201. The hydraulic pump 200 also includes a sensor 206 that detects the angular position and / or rotational speed of the shaft 204 at that time, and sends the detection information of the sensor 206 to a controller 207 via a signal line 208, and the controller 207 determines the phase of the volume cycle of each working chamber 202 at that time based on the detection information.

[0032] The working chambers 202 are each associated with a low pressure valve (LPV) 209 configured as an electronically actuated face-sealing poppet valve that is operable to selectively close the flow path from the working chambers 202 to a low pressure manifold 210. The low pressure manifold 210 may thereby connect one or more, or all, of the working chambers 202 associated with each pump element to a tank port 216.

[0033] The LPV 209 is a normally open solenoid valve that is passively open during the intake stroke when the pressure in the working chamber 202 is equal to or less than the pressure in the low pressure manifold 210, placing the working chamber 202 in fluid communication with the low pressure manifold 210, while the LPV 209 is connected to the controller 207 via an LPV control line 211 and can be selectively closed under active control by the controller 207, placing the working chamber 202 out of fluid communication with the low pressure manifold 210. The LPV 209 may alternatively be a normally closed solenoid valve.

[0034] Each of the working chambers 202 is further associated with a high pressure valve (HPV) 212 configured as a pressure actuated discharge valve. The HPV 212 opens outwardly from the respective working chamber 202 and is operable to seal a flow passage extending from the working chamber 202 to the high pressure manifold 213. When the HPV 212 is open, the high pressure manifold 213 connects the working chamber 202 to the discharge port 214, allowing pressurized oil to flow from the working chamber 202 to the discharge port 214. The HPV 212 functions as a normally closed pressure relief check valve that opens passively in balance with the biasing force of a biasing member within the HPV 212 due to a pressure differential across the HPV 212. In some embodiments, the HPV 212 also functions as a normally closed electromagnetic check valve that, once opened by the pressure within the working chamber 202, is selectively held open by the controller 207 via the HPV control line 215. Typically, the HPV 212 cannot be opened by the controller 207 against pressure in the high pressure manifold 213. The HPV 212 may also be open or partially open under the control of the controller 207 when there is pressure in the high pressure manifold 213 and no pressure in the working chamber 202.

[0035] In the discharge mode, the controller 207 selects a net volumetric flow rate from the working chamber 202 to the high pressure manifold 213 by the hydraulic pump 200 by actively closing one or more LPVs 209 near a maximum volumetric point in the volumetric cycle of the associated working chamber 202 to close the flow path to the low pressure manifold 210, thereby allowing hydraulic fluid to flow through the associated HPV 212 (but without actively opening the HPV 212) on the subsequent contraction stroke, resulting in a useful cycle with a net volumetric flow rate of the working chamber 202. Alternatively, the LPV 209 may be left open throughout the entire cycle of the working chamber 202 (or the working chamber 202 may be closed throughout the entire cycle), resulting in a non-useful cycle with no net volumetric flow rate. The controller 207 selects the number and sequence of useful and non-useful cycles to generate flow or generate shaft torque or power to meet the selected net volumetric flow rate of the working chamber 202 of the pump element connected to the same high pressure manifold 213 and discharge port 214, and to meet the flow rate demand of the pump element.

[0036] The controller 207 is operable not only to decide for each cycle whether to close or leave the LPV 209 open, selecting between active and inactive cycles, but also to precisely vary the phase at which the LPV 209 and / or HPV 212 are closed in relation to the changing volume of the working chamber 202, thereby selecting the net volumetric amount from the high pressure manifold 213 to the low pressure manifold 210 or vice versa.

[0037] The arrows on the manifolds 210, 213 indicate the flow of hydraulic fluid in pump mode, with the flow being reversed in motor mode.

[0038] While the illustrated example shows all working chambers 202 connected to the same high pressure manifold 213 and discharge port 214, typically the hydraulic pump 200 further comprises working chambers 202 forming one or more separate pump elements having their own high pressure manifold 213, discharge port 214, and demand signal.

[0039] More specifically, in the first hydraulic pump 11, four high-pressure manifolds 213 and four discharge ports 214 corresponding to the first discharge ports 45a, 45b, 45c, and 45d are provided, and each high-pressure manifold 213 is connected to the working chamber 202 via a high-pressure valve 209. The same is true for the second hydraulic pump 12.

[0040] The demand signal may be expressed in any suitable units. As an example, the demand signal is expressed as a "volume change rate Fd," which is the maximum possible volume change per revolution of the pump shaft 204. The target flow rate is expressed as the product of the volume change rate Fd and the rotational speed of the pump shaft 204.

[0041] [Parallel pump] Next, the structure of the parallel pump 30 according to this embodiment will be described with reference to FIGS.

[0042] Figure 3 is a horizontal cross-sectional view along pump shaft 14 of pump device 10 shown in Figure 2, Figure 4 is a vertical cross-sectional view of pump device 10 along line VI-VI in Figure 2, Figure 5 is a vertical cross-sectional view of pump device 10 along line VII-VII in Figure 2, Figure 6 is a vertical cross-sectional view of pump device 10 along line VIII-VIII in Figure 3, and Figure 7 is a top view of port block 13.

[0043] In FIG. 3, as described above, the parallel pump 30 includes a gearbox 47, a common pump casing 48, a first hydraulic pump 11 and a second hydraulic pump 12 formed within the common pump casing 48, and a port block 13.

[0044] The gear box 47 has a drive gear 47a and driven gears 47b, 47c, and the drive gear 47a is connected to the pump shaft 14. The first hydraulic pump 11 and the second hydraulic pump 12 are connected to the pump shaft 14 via the gear box 47. The port block 13 is a common component of the first hydraulic pump 11 and the second hydraulic pump 12, and is connected to the side surface of the pump casing 48 opposite the gear box 47. As shown in FIG. 7, a plurality of first discharge ports 45a, 45b, 45c, 45d and a plurality of second discharge ports 46a, 46b, 46c, 46d are formed to open on a side portion 13S, which is the upper surface of the port block 13.

[0045] In the illustrated embodiment, the side 13S of the port block 13 has a single block surface, and the first and second discharge ports 45a-45d, 46a-46d open onto that block surface; however, the side 13S of the port block 13 may be formed with multiple stepped surfaces, for example a first surface and a second surface parallel to the first surface, with the first discharge ports 45a-45d formed on the first surface and the second discharge ports 46a-46d formed on the second surface.

[0046] As described above, the first hydraulic pump 11 is configured to form a plurality of first pump elements 11a, 11b, 11c, 11d (see FIG. 15) capable of independently controlling the flow rate of the pressure oil discharged from a plurality of first discharge ports 45a-45d, and the second hydraulic pump 12 is configured to form a plurality of second pump elements 12a, 12b, 12c, 12d (see FIG. 15) capable of independently controlling the flow rate of the pressure oil discharged from a plurality of second discharge ports 46a-46d. In this embodiment, the plurality of first discharge ports 45a-45d and the plurality of second discharge ports 46a-46d are four first discharge ports and four second discharge ports, respectively, and the plurality of first pump elements 11a-11d and the plurality of second pump elements 12a-12d are also four first pump elements and four second pump elements, respectively. The number of first and second pump elements is not limited to four, and may be, for example, two, three, or five, so long as the pump device 10 becomes more compact than before.

[0047] The first and second hydraulic pumps 11, 12 are each connected to the pump shaft 14 via a gear box 47 and have first and second driven shafts 14a, 14b arranged parallel to each other on either side of the extension line of the axis of the pump shaft 14, with the first hydraulic pump 11 having two first radial piston pumps 36a, 36b arranged at intervals in the axial direction of the first driven shaft (hereinafter simply referred to as the first shaft) 14a, and the second hydraulic pump 12 having two second radial piston pumps 37a, 37b arranged at intervals in the axial direction of the second driven shaft (hereinafter simply referred to as the first shaft) 14b.

[0048] The common pump casing 48 of the first and second hydraulic pumps 11, 12 forms a first pump chamber 48a and a second pump chamber 48b, with the first radial piston pumps 36a, 36b being arranged in the first pump chamber 48a and the second radial piston pumps 37a, 37b being arranged in the second pump chamber 48b.

[0049] The shafts 14a and 14b are rotatably supported via bearings in the pump casing 48 and the port block 13, respectively. The ends of the shafts 14a and 14b opposite the port block 13 extend beyond the pump casing 48 into the gear box 47, and are connected to the pump shaft 14 via the driven gears 47b and 47c and the drive gear 47a of the gear box 47.

[0050] As shown in FIGS. 4 and 5, hydraulic oil is introduced from an oil tank 55 into the first and second pump chambers 48a, 48b of the pump casing 48 via a passage formed in the port block 13.

[0051] The first radial piston pump 36a has an eccentric cam 15 that rotates integrally with the shaft 14a, a piston 16 that comes into sliding contact with the outer circumferential surface of the eccentric cam 15, and a cylinder 19 in which the piston 16 reciprocates, and a cylinder chamber 49 is formed by the piston 16 and the cylinder 19. The first radial piston pump 36b also has a shaft 14a, an eccentric cam 15, the piston 16, the cylinder 19, and a cylinder chamber 49.

[0052] The second radial piston pumps 37a, 37b are similar and each include a shaft 14b, an eccentric cam 15, a piston 16, a cylinder 19, and a cylinder chamber 49.

[0053] In addition, the first radial piston pumps 36a, 36b have suction check valves 17a, 17b and discharge check valves 18a, 18b respectively communicating with the cylinder chamber 49, as shown in Figure 4, and the second radial piston pumps 37a, 37b have suction check valves 17c, 17d and discharge check valves 18c, 18d respectively communicating with the cylinder chamber 49, as shown in Figure 5.

[0054] The first radial piston pump 36a forms two of the first pump elements 11a and 11d out of the four first pump elements 11a to 11d described above, and the first radial piston pump 36b forms the remaining two first pump elements 11b and 11c.

[0055] The second radial piston pump 37a forms two of the four second pump elements 12a to 12d, that is, the second pump elements 12a and 12d, and the second radial piston pump 37b forms the remaining two second pump elements 12b and 12c.

[0056] The details will be explained below with reference to FIG.

[0057] As shown on the left side of Fig. 6, the first radial piston pump 36a has six piston pumps 60 each composed of a piston 16 and a cylinder 19 and arranged radially at an equal angle in the circumferential direction with respect to the shaft 14a, and when the eccentric cam 15 integral with the shaft 14a rotates, each piston 16 of the piston pumps 60 reciprocates in the cylinder 19, sucking the hydraulic oil filled in the first pump chamber 48a in the pump casing 48 from the suction check valve 17a (see Fig. 4) into the cylinder chamber 50, pressurizing the hydraulic oil, and discharging it from the discharge check valve 18a as pressurized oil. The discharged pressurized oil passes through the internal passages 61a, 61d of the pump casing 48, flows into the port block 13 from the openings 62a, 62d formed on the side surface of the pump casing 48, and is guided to any one of the first discharge ports 45a to 45d shown in Fig. 7, the first discharge ports 45a, 45d in the illustrated embodiment, and is discharged from the discharge ports 45a, 45d.

[0058] The first radial piston pump 36b is configured in a similar manner, and the pressurized oil discharged from the discharge check valve 18b shown in Figure 4 is guided through the internal passage of the pump casing 48 and the port block 13 to the first discharge ports 45b, 45c shown in Figure 7, and is discharged from the discharge ports 45b, 45c.

[0059] The second radial piston pumps 37a and 37b are similar to the above. That is, the second radial piston pump 37a is also composed of a piston 16 and a cylinder 19, and is arranged in a circumferential direction with respect to the shaft 14b, for example, as shown on the right side of FIG. The second radial piston pump 37b has six piston pumps 60 arranged radially at equal angles, and is similarly configured. In the case of the second radial piston pump 37a, the pressure oil discharged from the discharge check valve 18c passes through the internal passages 63a, 63d of the pump casing 48, flows into the port block 13 from the openings 64a, 64d formed on the side of the pump casing 48, is guided to the first discharge ports 46a, 46d shown in Fig. 7, and is discharged from the discharge ports 46a, 46d. In the case of the second radial piston pump 37b, the pressure oil discharged from the discharge check valve 18d shown in Fig. 5 passes through the internal passages of the pump casing 48 and the port block 13, is guided to the second discharge ports 46b, 46c shown in Fig. 7, and is discharged from the discharge ports 46b, 46c.

[0060] 4 and 5, suction check valve 17a is an electromagnetic on / off valve (hereinafter referred to as solenoid valve), and when the solenoid valve is OFF, the valve is always open by a spring, as shown in suction check valve 17a. Therefore, the hydraulic oil sucked into the cylinder chamber 50 when the piston 16 descends returns from suction check valve 17a to the pump casing 48 when the piston 16 ascends, and is not discharged. By turning the solenoid valve ON when the piston 16 ascends, the valve closes as shown in suction check valve 17b, the cylinder chamber 50 is pressurized, and discharge check valve 18b opens, and discharge is performed. Also, by controlling the timing of turning ON and OFF, the timing of closing the suction check valve is controlled, and the discharge flow rate in one stroke of the piston 16 can be controlled.

[0061] In this way, by controlling the ON / OFF of the solenoid valves and the timing at which they are turned ON / OFF, it is possible to independently control the discharge flow rate of each of the six piston pumps 60 in each of the first radial piston pumps 36a, 36b and the second radial piston pumps 37a, 37b.

[0062] In addition, by dividing the six piston pumps 60 of the first radial piston pump 36a into a plurality of groups and merging the discharge oil of the piston pumps 60 for each group and discharging it from the discharge port, it is possible to discharge a plurality of pressurized oils from the six piston pumps 60 of the first radial piston pump 36a. The same is true for the first radial piston pump 36b and the second radial piston pumps 37a, 37b. In this specification, each of the six piston pumps 60 of each radial piston pump divided into a plurality of groups and the discharge oil of the piston pumps 60 for each group merged and discharged from the discharge port is called a "pump element."

[0063] In this embodiment, in order to reduce pump pulsation, the six piston pumps 60 of each radial piston pump are divided into two groups, and one pump element is formed using three piston pumps 60.

[0064] More specifically, six piston pumps 60 of the first radial piston pump 36a of the first hydraulic pump 11 form two pump elements 11a and 11d, and six piston pumps 60 of the first radial piston pump 36b form two pump elements 11b and 11c, and pressure oil from the pump elements 11a to 11d is discharged from four discharge ports 45a to 45d. Similarly, six piston pumps 60 of the second radial piston pump 37a of the second hydraulic pump 12 form two pump elements 12a and 12d, and six piston pumps 60 of the second radial piston pump 37b of the second hydraulic pump 12 form two pump elements 12b and 12c, and pressure oil from the pump elements 12a to 12d is discharged from four discharge ports 46a to 46d.

[0065] This will be further explained with reference to FIG.

[0066] In Fig. 6, the six piston pumps 60 of the first radial piston pump 36a are indicated by symbols 60a, 60b, 60c, 60d, 60e, and 60f in a clockwise direction. The discharge oils of the piston pumps 60a, 60c, and 60e are merged to form the pump element 11a, and the discharge oils of the piston pumps 60b, 60d, and 60f are merged to form the pump element 11d. The respective merged discharge flow rates flow into the port block 24 from the openings 62a and 62d, and are led to the discharge ports 45a and 45d shown in Fig. 7. Similarly, the first radial piston pump 36b of the first hydraulic pump 11 forms two pump elements 11b and 11c, and the respective merged discharge flow rates are led to the discharge ports 45b and 45c shown in Fig. 7.

[0067] The second radial piston pumps 37a, 37b of the second hydraulic pump 12 are similar, and the second radial piston pump 37a forms two pump elements 12a, 12d, and the combined discharge flow rates of the two pump elements are led to discharge ports 46a, 46d shown in Figure 7, while the second radial piston pump 37b forms two pump elements 12b, 12c, and the combined discharge flow rates of the two pump elements are led to discharge ports 46b, 46c shown in Figure 7.

[0068] In this way, the six piston pumps 60 of each of the two first radial piston pumps 36a, 36b are each divided into two groups, and the pressurized oil discharged from each piston pump 60 for each group is joined together to form four pump elements 11a-11d of the first hydraulic pump 11. Similarly, the six piston pumps 60 of each of the two second radial piston pumps 37a, 37b are each divided into two groups, and the pressurized oil discharged from each piston pump 60 for each group is joined together to form four pump elements 12a-12d of the second hydraulic pump 12.

[0069] In this embodiment, as shown in Fig. 3, the first radial piston pumps 36a, 36b are arranged to be aligned with the second radial piston pumps 37a, 37b in the axial direction of the first and second driven shafts 14a, 14b. However, this is only one example, and the first radial piston pumps 36a, 36b may be arranged to be offset from the second radial piston pumps 37a, 37b in the axial direction of the first and second driven shafts 14a, 14b. In this case, the radial range of the first radial piston pumps 36a, 36b in the direction toward the second driven shaft 14b may extend beyond the radial range of the second radial piston pumps 37a, 37b in the direction toward the first driven shaft 14a. This allows the configuration of the parallel pump 30 to be made compact.

[0070] [Manifold block] Figure 8 is a top view of manifold block 40, Figure 9 is a bottom view of manifold block 40, Figure 10 is a horizontal cross-sectional view of manifold block 40 taken along line XII-XII in Figure 4, and Figure 11 is a vertical cross-sectional view of manifold block 40 taken along line XIII-XIII in Figure 8.

[0071] 8 to 11, the manifold block 40 has a long and narrow rectangular parallelepiped shape with a rectangular cross section, and has a block body 40a with opposing side surfaces 40b, 40c, to which the above-mentioned four first switching valves 41a to 41d and four second switching valves 42a to 42d are attached. The first switching valves 41a to 41d and the second switching valves 42a to 42d are electromagnetic switching valves equipped with solenoid portions 41s, 42s at one end, respectively.

[0072] The first switching valves 41a to 41d are attached to the block body 40a such that their solenoid parts 41s protrude from the side 40b of the block body 40a opposite the gear box 47, which is one of the opposing side surfaces 40b and 40c of the block body 40a, on the side where the first hydraulic pump 11 is located in the longitudinal direction of the block body 40a, as shown in Figures 4, 8, and 10. The second switching valves 42a to 42d are attached to the block body 40a such that their solenoid parts 42s protrude from the side 40c of the block body 40a on the gear box 47 side, which is the other of the opposing side surfaces 40b and 40c of the block body 40a, on the side where the second hydraulic pump 12 is located in the longitudinal direction of the block body 40a, as shown in Figures 5, 8, and 10.

[0073] Furthermore, as shown in FIG. 8, two first and second service ports 43, 44 are formed on the upper surface 40S of the block body 40a of the manifold block 40, which are connected to the control valve 20 (see FIG. 15) via first and second hydraulic hoses 51, 52 (see FIG. 15), and as shown in FIG. 9, four first inlet ports 65a-65d and four second inlet ports 66a-66d are formed on the bottom surface of the block body 40a, into which pressurized oil flows in from the four first discharge ports 45a, 45b, 45c, 45d and the four second discharge ports 46a, 46b, 46c, 46d, respectively.

[0074] As mentioned above, the first discharge ports 45a, 45b, 45c, 45d and the second discharge ports 46a, 46b, 46c, 46d are formed to open to the side (upper surface) 13S of the port block 13, and the manifold block 40 is connected to the side 13S of the port block 13 with bolts or the like so that the four first inlet ports 65a to 65d are aligned with the four first discharge ports 45a to 45d (see Figure 7) formed in the side 13S of the port block 13, and the four second inlet ports 66a to 66d are aligned with the four second discharge ports 46a to 46d (see Figure 7) formed in the side 13S of the port block 13.

[0075] By connecting the manifold block 40 to the side 13S of the port block 13 in this manner, hydraulic hoses are not required to connect the first discharge ports 45a-45d and the second discharge ports 46a-46d of the port block 13 to the first switching valves 41a-41d and the second switching valves 42a-42d, and the pump unit 10 including the manifold block 40 can be made smaller, improving the ease of mounting the pump unit 10 on construction machinery.

[0076] The four first switching valves 41a to 41d are incorporated in the block body 40a of the manifold block 40 to switch the flow direction of the pressurized oil flowing in from the four first inlet ports 65a to 65d so as to guide the pressurized oil flowing in from the four first inlet ports 65a to 65d to one of the two service ports 43, 44, and the four second switching valves 42a to 42d are incorporated in the block body 40a of the manifold block 40 to switch the flow direction of the pressurized oil flowing in from the four second inlet ports 66a to 66d so as to guide the pressurized oil flowing in from the four second inlet ports 66a to 66d to one of the two service ports 43, 44.

[0077] More specifically, a first inlet port 65a formed in the block body 40a is provided as an inlet port of the first switching valve 41a, as shown in FIG. 11, and two outlet ports 67a, 68a are formed on the outlet side of the first switching valve 41a, and the outlet ports 67a, 68a are respectively connected to internal passages 43a, 44a formed in the block body 40a.

[0078] Although not shown, the first inlet ports 65b to 65d are similarly provided as inlet ports of the first switching valves 41b to 41d, respectively, and two outlet ports are formed on the outlet sides of the first switching valves 41b to 41d, and these outlet ports are also respectively connected to the internal passages 43a, 44a formed in the block body 40a.

[0079] The same is true for the second inlet ports 66a to 66d (see Figure 9), which are respectively provided as inlet ports of the second switching valves 42a to 42d, and two outlet ports (not shown) are formed on the outlet sides of the second switching valves 42a to 42d, and these outlet ports are also respectively connected to the internal passages 43a, 44a.

[0080] In Fig. 11, a drain passage 69a communicating with an oil tank 55 communicating with the tank via the first pump chamber 48a is formed at the bottom of the valve chamber into which the spool portion of the first switching valve 41a is inserted, allowing the spool portion to move within the valve chamber. The drain passage is not shown in Figs. 12, 15, etc., which will be described later.

[0081] The two internal passages 43a, 43b are located above the first switching valves 41a-41d and the four second switching valves 42a-42d, and are formed parallel to each other with both ends closed as shown by the dashed lines in Fig. 8. The first and second service ports 43, 44 formed on the upper surface 40S of the block body 40a are formed to communicate with the internal passages 43a, 44a, respectively. One end of the internal passages 43a, 43b may be left open, and the opening may be used as a service port.

[0082] Figure 12 is a diagram showing the connection state between the first inlet port 65a and the two internal passages 43a, 44a when the first switching valve 41a is in the initial position, and Figure 13 is a diagram showing the connection state between the first inlet port 65a and the two internal passages 43a, 44a when the first switching valve 41a is switched from the initial position to the non-initial position.

[0083] As shown in Fig. 12, when the first switching valve 41a is in the initial position, the first inlet port 65a communicates with the internal passage 43a via the linear outlet port 67a, and when the first switching valve 41a is switched from the initial position to the non-initial position, the first inlet port 65a communicates with the internal passage 44a via the L-shaped outlet port 68a, as shown in Fig. 13. Although not shown, the first switching valves 41b to 41d are configured in a similar manner.

[0084] The same is true for the second switching valves 42a to 42d; when in the initial position, the second inlet ports 66b to 66d each communicate with the internal passage 44a via one of two outlet ports (not shown), and when the second switching valves 42a to 42d are switched from the initial position to the non-initial position, the second inlet ports 66b to 66d each communicate with the internal passage 43a via the other of the two outlet ports (not shown).

[0085] However, since the second switching valves 42a-42d are attached so as to protrude from the side surface 40c of the manifold block 40 opposite to the first switching valves 41a-41d, when viewed in the same cross-sectional views as Figures 11-13, the two outlet ports have shapes opposite to those of the outlet ports 67a, 68a shown in Figures 11-13. That is, of the two outlet ports, the outlet port connected to the internal passage 43a is L-shaped, and the outlet port connected to the internal passage 44a is linear.

[0086] In this way, by attaching the first switching valves 41a to 41d to the block body 40a so that their solenoid parts 41s protrude from side 40b, which is one of the opposing side surfaces 40b, 40c of the block body 40a, and attaching the second switching valves 42a to 42d to the block body 40a so that their solenoid parts 42s protrude from side 40c, which is the other of the opposing side surfaces 40b, 40c of the block body 40a, it is possible to configure the manifold block 40 using switching valves with the same spool shape. This makes it easy to manufacture the manifold block 40.

[0087] The pressurized oil discharged from the four pump elements 11a to 11d of the first hydraulic pump 11 flows from the four first discharge ports 45a to 45d (see Figure 7) formed on the upper surface 13S of the port block 13 into the four first inlet ports 65a to 65d of the manifold block 40, and flows into the internal passages 43a and / or 44a through either the outlet port 67a (the other three outlet ports are not shown) or the outlet port 68a (the other three outlet ports are not shown) depending on the switching position of the first switching valves 41b to 41d, and is supplied to the control valve 20 (see Figures 14 and 15) from the first and second service ports 43 and / or 44.

[0088] The pressurized oil discharged from the four pump elements 12a-12d of the second hydraulic pump 12 similarly flows into the internal passages 43a and / or 44a via the four second discharge ports 46a-46d (see Figure 7) formed on the upper surface 13S of the port block 13, the four second inlet ports 66a-66d of the manifold block 40, the second switching valves 42b-42d, and an outlet port not shown, and is supplied from the first and second service ports 43 and / or 44 to the control valve 20 (see Figures 14 and 15).

[0089] ~Pump unit layout for the upper rotating body~ FIG. 14 is a layout diagram showing the state in which the pump device 10 is mounted on an upper rotating body 102. As shown in FIG.

[0090] In Figure 14, the engine 1, which is the prime mover, the pump unit 10, the control valve 20, and the oil tank 55 are mounted on a rotating frame 102b, which is the base of the upper rotating body 102, and an opening / closing cover 102c is provided on the side panel on the left side of the upper rotating body 102 to allow the operator to access the pump room in which the pump unit 10 is located.

[0091] The pump device 10 is located on the opposite side of the cooling fan 1b of the engine 1, and a pump shaft 14 (see FIG. 2) of the parallel pump 30 is connected to the output shaft of the engine 1. In addition, a port block 13 (see FIG. 3) is located on the opposite side of the parallel pump 30 to the output shaft of the engine 1 (the opening and closing cover 102c side), and a manifold block 40 is mounted on an upper surface 13S of this port block 13. The manifold block 40 includes first switching valves 41a-41d and second switching valves 42a-42d, and first and second service ports 43, 44 are formed on the upper surface of the manifold block 40.

[0092] The first switching valves 41a to 41d are mounted on the manifold block 40 so that their respective solenoid portions 41s protrude from the side 40b on the opposite side of the gear box 47 where the pump shaft 14 of the manifold block 40 is located (i.e., the opposite side of the engine 1), and the second switching valves 42a to 42d are mounted on the manifold block 40 so that their respective solenoid portions 42s protrude from the side of the manifold block 40 on the gear box 47 side (i.e., the engine 1 side).

[0093] The control valve 20 is composed of two valve groups, a first valve group 33 of four valves and a second valve group 34 of five valves, and a first service port 43 of the manifold block 40 is connected to the first valve group 33 of the control valve 20 via a first hydraulic hose 51, and a second service port 44 is connected to the second valve group 34 of the control valve 20 via a second hydraulic hose 52. The first and second hydraulic hoses 51, 52 rise upward from the upper surface 40S of the manifold block 40, then extend in the direction of the oil tank 55, and are routed from the manifold block 40 to the control valve 20, passing beside the oil tank 55.

[0094] ~Application examples of hydraulic circuit systems~ [System Configuration] FIG. 15 is a diagram showing an example of a hydraulic circuit system in which the pump device 10 according to the above-described first embodiment of the present invention is applied to a two-pump, two-valve group system.

[0095] In Figure 15, the hydraulic circuit system includes an engine 1 which is the prime mover described above, a pump device 10 driven by the engine 1, a plurality of actuators 104a-108d (see Figure 1 for actuators 106a-108d) driven by pressurized oil discharged from the pump device 10, a plurality of directional control valves 21-29 which control the flow of pressurized oil supplied from the pump device 10 to the plurality of actuators 104a-108d, and a plurality of operating lever devices 56a, 56b, 56c, 56d which switch the plurality of directional control valves 21-29 and operate the plurality of actuators 104a-108d.

[0096] The pump device 10 is the pump device described above, and includes a parallel pump 30 having a first hydraulic pump 11 and a second hydraulic pump 12, and a manifold block 40 that switches the flow direction of the pressurized oil discharged from the parallel pump 30. The first and second hydraulic pumps 11, 12 are driven by the engine 1, and discharge the pressurized oil sucked from the oil tank 55. An electric motor may be used instead of the engine 1.

[0097] The first and second hydraulic pumps 11, 12 each have four first discharge ports 45a-45d and four second discharge ports 46a-46d, and the first hydraulic pump 11 contains four first pump elements 11a-11d that can independently control the flow rate of pressurized oil discharged from the four first discharge ports 45a-45d, and the second hydraulic pump 12 contains four second pump elements 12a-12d that can independently control the flow rate of pressurized oil discharged from the four second discharge ports 46a-46d.

[0098] The manifold block 40 has four first switching valves 41a-41d and four second switching valves 42a-42d, and is configured to switch the flow direction of pressurized oil flowing in from the first discharge ports 45a-45d and the second discharge ports 46a-46d by the first switching valves 41a-41d and the second switching valves 42a-42d, and to guide the pressurized oil to either the first service port 43 or the second service port 44.

[0099] Moreover, the first switching valves 41a-41d and the second switching valves 42a-42d are electromagnetic switching valves that can be switched between a first position which is an initial position and a second position which is a non-initial position, and the first switching valves 41a-41d, in the first position, communicate the first discharge ports 45a-45d with the first service port 43, and in the second position, communicate the first discharge ports 45a-45d with the second service port 44. The hydraulic circuit is configured such that the second switching valves 42a-42d, in the first position, communicate the second discharge ports 46a-46d with the second service port 44, and in the second position, communicate the second discharge ports 46a-46d with the first service port 43.

[0100] The first service port 43 and the second service port 44 of the manifold block 40 are connected via a first hydraulic hose 51 and a second hydraulic hose 52 to a control valve 20 which houses a plurality of directional control valves 21-29 within a valve housing.

[0101] The multiple actuators 104a to 108d are respectively the boom cylinder 104a, the arm cylinder 105a, the bucket cylinder 106a, the swing motor 107a, the left traveling motor 108c, and the right traveling motor 108d shown in Figure 1, and the multiple directional control valves 21 to 29 are respectively the right traveling directional control valve 21, the bucket directional control valve 22, the boom I directional control valve 23, the boom II directional control valve 27, the arm II directional control valve 24, the swing directional control valve 25, the arm I directional control valve 26, the spare directional control valve 28, and the left traveling directional control valve 29.

[0102] The operating lever device 56a is for the boom 104 and bucket 106, the operating lever device 56b is for the arm 105 and swivel device 107, the operating lever device 56c is for the left traveling device 108a, and the operating lever device 56d is for the right traveling device 108b.

[0103] The multiple directional control valves 21-29 are divided into a first valve group 33 of four valves including a boom I directional control valve 23 and a boom II directional control valve 27, which are directional control valves for a specific first actuator that is operated relatively frequently, and a second valve group 34 of five valves including an arm I directional control valve 26 and an arm II directional control valve 24, which are directional control valves for a specific second actuator that is operated relatively frequently. The control valve 20 has first and second pump ports 31, 32 connected to the first and second valve groups 33, 34, and the first and second pump ports 31, 32 are connected to first and second service ports 43, 44 via first and second hydraulic hoses 51, 52.

[0104] The number of the first and second service ports 43, 44 is the same as the number of the valve groups 33, 34 included in the control valve 20 (the number of the first and second pump ports), ie, two.

[0105] Note that the number of the multiple service ports of manifold block 40 only needs to be the same as the number of multiple valve groups included in control valve 20, so for example, if control valve 20 includes three valve groups, the number of multiple service ports of manifold block 40 will also be three. In this case, as the number of service ports increases from two to three, the outlet sides of first switching valves 41a-41d and multiple second switching valves 42a-42d can be connected to three service ports so that the pressure oil discharged from first pump elements 11a-11d and second pump elements 12a-12d is distributed to the three service ports.

[0106] Pressurized oil from the first service port 43 passes through the first hydraulic hose 51 and flows into the control valve 20 from the pump port 31, and is supplied to the right traveling directional control valve 21, the bucket directional control valve 22, the boom I directional control valve 23, and the boom II directional control valve 27 of the first valve group 33. Pressurized oil from the second service port 44 passes through the second hydraulic hose 52 and flows into the control valve 20 from the pump port 32, and is supplied to the swing directional control valve 25, the arm I directional control valve 26, the arm II directional control valve 24, the spare directional control valve 28, and the left traveling directional control valve 29 of the second valve group 34.

[0107] The first valve group 33 is configured as an open center circuit in which the directional control valves 21, 22, 23, 27 are arranged in a center bypass line 33a and the directional control valves 21, 22, 23, 27 are connected in parallel to each other, and the second valve group 34 is configured as an open center circuit in which the directional control valves 24, 25, 26, 28, 29 are arranged in a center bypass line 34a and the directional control valves 24, 25, 26, 28, 29 are connected in parallel to each other.

[0108] The directional control valves 21-29 are electromagnetic control valves that operate based on commands output from the controller 57. When the levers of the operating lever devices 56a, 56b, 56c, and 56d are not operated and there is no command from the controller 57, they are in a neutral state, and the pressure oil flowing in from the pump port 32 flows back to the oil tank 55 through the center bypass lines 33a and 34a. When the levers of the operating lever devices 56a, 56b, 56c, and 56d are operated and a command is generated from the controller 57, the directional control valves 21-29 switch from the neutral state, adjust the flow rate distribution of the pressure oil flowing in from the pump ports 31 and 32, and supply the pressure oil to the respective actuators 104a-108d. Also, when the boom I directional control valve 23 and the boom II directional control valve 27 switch from the neutral state, the pressure oils from these directional control valves 23 and 27 join together and are supplied to the boom cylinder 104a. When the arm I directional control valve 26 and the arm II directional control valve 24 also switch from the neutral state, the pressure oil from these directional control valves 24, 26 joins together and is supplied to the arm cylinder 105a.

[0109] Controller 57 inputs operation signals from operating lever devices 56a-56d and sensor signals such as the RPM of engine 1 and the pressure of each part, such as the discharge pressure of first and second hydraulic pumps 11, 12, and issues commands based on these signals to pump controllers 58, 59, switching valves 41a-41d, 42a-42d, and directional control valves 21-29. Pump controllers 58, 59 control suction check valves 17a, 17b and suction check valves 17c, 17d based on commands from controller 57, and independently control the discharge flow rates of first and second pump elements 11a-11d, 12a-12d.

[0110] The rotation speed of the engine 1 can be detected, for example, by arranging a rotation sensor such as an encoder on the shaft 14 (see FIG. 2) of the first hydraulic pump 11 or the second hydraulic pump 12. The discharge pressure of the first and second hydraulic pumps 11, 12 can be detected, for example, by connecting a pressure sensor to the first and second hydraulic hoses 51, 52. The sensor signal of the rotation sensor is used to control the flow rate of the pressurized oil of the first and second pump elements 11a-11d, 12a-12d, and the sensor signal of the pressure sensor is used to control the horsepower of the pressurized oil of the first and second pump elements 11a-11d, 12a-12d.

[0111] [Operation] Next, an example of the operation of the boom 104 and the arm 105 in the above hydraulic circuit system will be described.

[0112] <<Non-operation>> 15, when the levers of the operating lever devices 56a-56d are not operated and there is no command from the controller 57, the switching valves 41a-41d, 42a-42d are in the positions shown in the figure, the four pump elements 11a-11d in the first hydraulic pump 11 are connected to the first valve group 33, and the four pump elements 12a-12d in the second hydraulic pump 12 are connected to the second valve group 34. In addition, the pump elements 11a-11d, 12a-12d have a discharge flow rate of zero or discharge a very small amount of flow. Since the directional control valves 21-29 are in a neutral state, the pressure oil flows to the oil tank 55 through the center bypass lines 33a, 34a.

[0113] <<Boom independent drive>> When the lever of the operating lever device 56a is operated in the boom drive direction, the boom I directional control valve 23 and the boom II directional control valve 27 are displaced according to the lever operation amount (required flow rate) in response to a command from the controller 57, and the boom cylinder 104a is driven by pressure oil from the first hydraulic pump 11. Also, the flow rate of the first hydraulic pump 11 increases according to the lever operation amount in response to a command from the pump controller 58. That is, first, the discharge flow rate of the pump element 11a starts to increase, and when the pump element 11a reaches its maximum flow rate, the discharge flow rate of the pump element 11b increases. When the pump element 11b reaches its maximum flow rate, the discharge flow rate of the pump element 11c increases, and when the pump element 11c reaches its maximum flow rate, the discharge flow rate of the pump element 11d increases.

[0114] The pressurized oil discharged from the first pump elements 11a-11d is supplied to the boom I directional control valve 23 and the boom II directional control valve 27 via the first discharge ports 45a-45d, the first inlet ports 65a-65d, the first switching valves 41a-41d, the internal passage 43a, the first service port 43, the first hydraulic hose 51, and the first pump port 31, and is further supplied to the boom cylinder 104a.

[0115] If the amount of lever operation increases further and the required flow rate of the boom cylinder 104a cannot be met by the first hydraulic pump 11 alone, the switching valve 42a can be switched to add the flow rate of the pump element 12a, and the full flow rate of the second hydraulic pump 12 can be added by switching the switching valves 42a, 42b, 42c, and 42d.

[0116] The pressurized oil discharged from the second pump elements 12a-12d is supplied to the boom I directional control valve 23 and the boom II directional control valve 27 via the second discharge ports 46a-46d, the second inlet ports 66a-66d, the second switching valves 42a-42d, the internal passage 43a, the first service port 43, the first hydraulic hose 51, and the first pump port 31, and further to the boom cylinder 104a.

[0117] In this way, all eight pump elements 11a to 11d, 12a to 12d can be connected to the boom cylinder 104a, thereby enabling high speed operation of the boom cylinder 104a.

[0118] <<Independent arm drive>> When the lever of the operating lever device 56b is operated in the arm drive direction, the arm I directional control valve 26 and the arm II directional control valve 24 are displaced according to the amount of lever operation by a command from the controller 57, and the arm cylinder 105a is driven by pressure oil from the second hydraulic pump 12. Also, by a command from the pump controller 59, the flow rate of the second hydraulic pump 12 also increases according to the amount of lever operation, and first the discharge flow rate of the pump element 12a starts to increase, and when the pump element 12a reaches its maximum flow rate, the discharge flow rate of the pump element 12b increases. When the pump element 12b reaches its maximum flow rate, the discharge flow rate of the pump element 12c increases, and when the pump element 12c reaches its maximum flow rate, the discharge flow rate of the pump element 12d increases.

[0119] The pressurized oil discharged from the second pump elements 12a-12d is supplied to the arm I directional control valve 26 and the arm II directional control valve 24 via the second discharge ports 46a-46d, the second inlet ports 66a-66d, the second switching valves 42a-42d, the internal passage 44a, the second service port 44, the second hydraulic hose 52, and the second pump port 32, and is further supplied to the brake arm cylinder 105a.

[0120] If the amount of lever operation increases further and the required flow rate of the arm cylinder 105a cannot be met by the second hydraulic pump 12 alone, the switching valve 41a can be switched to add flow rate from the pump element 11a, and the full flow rate of the first hydraulic pump 11 can be added by switching the switching valves 41a, 41b, 41c, and 41d.

[0121] The pressurized oil discharged from the first pump elements 11a-11d is supplied to the boom I directional control valve 23 and the boom II directional control valve 27 via the first discharge ports 45a-45d, the first inlet ports 65a-65d, the first switching valves 41a-41d, the internal passage 44a, the second service port 44, the second hydraulic hose 52, and the second pump port 32, and is further supplied to the arm cylinder 105a.

[0122] In this manner, all eight pump elements 11a to 11d, 12a to 12d can be connected to the arm cylinder 105a, thereby enabling high speed operation of the arm cylinder 105a.

[0123] <<Simultaneous drive of boom and arm>> When the boom 104 and the arm 105 are operated simultaneously, when the lever of the operating lever device 56a is operated in the boom drive direction and the lever of the operating lever device 56b is operated in the arm drive direction, the boom I directional control valve 23 and the boom II directional control valve 27 are displaced according to the lever operation amount (required flow rate) by a command from the controller 57, and the arm I directional control valve 26 and the arm II directional control valve 24 are displaced. Also, at this time, for example, when the lever of the operating lever device 56a is input at 20% of the full operation amount and the lever of the operating lever device 56b is input at 20% of the full operation amount, the pump elements 11a, 11b and the pump elements 12a, 12b discharge pressure oil, and the boom cylinder 104a is driven by the pressure oil from the pump elements 11a, 11b, and the arm cylinder 105a is driven by the pressure oil from the pump elements 12a, 12b. If a demand is input that exceeds the combined maximum flow rate of all eight pump elements 11a to 11d, 12a to 12d, for example if the lever of operating lever device 56a is set at 100% and the lever of operating lever device 56b is set at 60%, pump elements 11a to 11d, 12a to 12d are allocated according to the ratio of the two (100:60 → 5:3), and boom cylinder 104a is driven by the five pump elements 11a, 11b, 11c, 11d, and 12a, and arm cylinder 105a is driven by the three pump elements 12d, 12c, and 12b.

[0124] In this way, the boom cylinder 104a and the arm cylinder 105a are driven independently without the pressure oil supplied from each pump element being divided, so each pump element only needs to supply the boom cylinder 104a and the arm cylinder 105a with a flow rate of the minimum pressure required. Therefore, there is no need to reduce the pressure by throttling the pressure oil with a directional control valve, and the division loss can be reduced.

[0125] ~Effects~ According to this embodiment, the following effects can be obtained.

[0126] 1. If the first and second switching valves 41a-41d, 42a-42d were installed away from the port block 13 of the parallel pump 30 as in the conventional case, eight hydraulic hoses would be required to connect the first and second discharge ports 45a-45d, 46a-46d to the first and second switching valves 41a-41d, 42a-42d, and in order to connect the eight hydraulic hoses to the first and second discharge ports 45a-45d, 46a-46d, the mountability would be reduced in order to secure space for the hydraulic hoses to pass through, and many problems would arise, such as an increase in the number of hose connection steps and a risk of leakage and reliability due to an increase in hydraulic connections. In addition, since it is necessary to increase the distance between the first and second discharge ports 45a-45d, 46a-46d in order to connect the eight hydraulic hoses, the port block 13 would become larger, and the pump device 10 would also become larger, which would also reduce the mountability.

[0127] In this embodiment, the first discharge ports 45a, 45b, 45c, 45d and the second discharge ports 46a, 46b, 46c, 46d are formed to open to the side (top surface) 13S of the port block 13, and the manifold block 40 is connected to the top surface 13S of the port block 13 with bolts or the like so that the four first inlet ports 65a to 65d are aligned with the four first discharge ports 45a to 45d (see Figure 7) formed on the top surface 13S of the port block 13, and the four second inlet ports 66a to 66d are aligned with the four second discharge ports 46a to 46d (see Figure 7) formed on the top surface 13S of the port block 13.

[0128] As a result, when two hydraulic pumps 11, 12 capable of independently controlling the flow rate of pressurized oil discharged from the multiple discharge ports (first and second discharge ports) 45a-45d, 46a-46d are arranged to form a parallel pump 30 and used as a hydraulic source for a hydraulic circuit system, it is possible to eliminate all of the numerous hydraulic hoses for connecting the multiple discharge ports (first and second discharge ports) 45a-45d, 46a-46d to the first switching valves 41a-41d and second switching valves 42a-42d of the manifold block 40, and it is possible to reduce the size of the pump unit 10 including the manifold block 40, thereby improving the mountability of the pump unit 10 on a construction machine.

[0129] Furthermore, since no hydraulic hose connection work is required, the pump device 10 can be easily installed, and since there are fewer leak points, reliability against leaks can be improved.

[0130] Furthermore, in this embodiment, as described above, when the boom 104 is operated alone, the boom cylinder 104a is driven using the eight pump elements 11a-11d, 12a-12d, so the discharge flow rate can be finely controlled according to the lever operation amount, the speed fluctuation of the boom cylinder 104a becomes smooth, and operability is improved. Also, by supplying the discharge flow rates of all eight pump elements 11a-11d, 12a-12d to the boom cylinder 104a, high-speed operation of the boom cylinder 104a is possible, and the amount of work can be secured.

[0131] The same is true when the arm 105 is operated alone; the discharge flow rate can be precisely controlled according to the amount of lever operation, improving operability, and enabling high-speed operation of the arm cylinder 105a, ensuring a sufficient amount of work.

[0132] In this embodiment, the number of pump elements of the first hydraulic pump 11 and the second hydraulic pump 12 is four each, and the corresponding numbers of the discharge ports and the first and second switching valves are also four each, but this is not limited to this. The number of pump elements of the first hydraulic pump 11 and the second hydraulic pump 12 may be two or more, such as two, three, or five, and the corresponding numbers of the discharge ports and the first and second switching valves may also be two or more, which also allows the above-mentioned effects to be obtained in terms of mountability, compactness, reliability, operability, workload, etc.

[0133] 2. The first switching valves 41a to 41d are attached to the block body 40a so that the solenoid parts 41s protrude from the side 40b, which is one of the opposing side surfaces 40b, 40c of the block body 40a, and the second switching valves 42a to 42d are attached to the block body 40a so that the solenoid parts 42s protrude from the side 40c, which is the other of the opposing side surfaces 40b, 40c of the block body 40a. This makes it possible to configure the manifold block 40 using switching valves with the same spool shape, making it easier to manufacture the manifold block 40.

[0134] 3. The number of the multiple service ports 43, 44 of the manifold block 40 is the same as the number of the valve groups 33, 34 included in the control valve 20, and the multiple service ports 43, 44 of the manifold block 40 are formed to open on the upper surface 40S of the manifold block 40. The service ports 43, 44 are connected to the control valve 20 via two hydraulic hoses 51, 52. For this reason, as shown in FIG. 14, by forming the service ports 43, 44 on the upper surface 40S of the manifold block 40 and connecting the two hydraulic hoses 51, 52 to the service ports 43, 44, the two hydraulic hoses 51, 52 can be raised upward from the upper surface 40S of the manifold block 40 and routed to the control valve 20 by passing beside the oil tank 55, and the routing of the hydraulic hoses 51, 52 from the manifold block 40 to the control valve 20 becomes simple and easy, and the mountability of the pump device 10 on the construction machine can be further improved.

[0135] 4. The hydraulic circuit is configured such that, in the first position, the first switching valves 41a to 41d connect the first discharge ports 45a to 45d to the first service port 43, and in the second position, the first discharge ports 45a to 45d connect to the second service port 44, and the second switching valves 42a to 42d connect the second discharge ports 46a to 46d to the second service port 44, and in the second position, the second discharge ports 46a to 46d connect to the first service port 43.

[0136] Therefore, when the pump elements 11a-11d are sequentially connected to the boom cylinder 104a in accordance with the lever operation amount (required flow rate) to supply the discharge flow rate of the pump elements 11a-11d to the boom cylinder 104a, the discharge flow rate can be supplied without switching the switching valves 41a-41d, so that the boom cylinder 104a can be smoothly started or accelerated without causing pressure fluctuations due to switching of the switching valves 41a-41d. The same is true when the pump elements 12a-12d are sequentially connected to the arm cylinder 105a in accordance with the lever operation amount (required flow rate) to supply the discharge flow rate of the pump elements 12a-12d to the arm cylinder 105a, so that the arm cylinder 105a can be smoothly started or accelerated without causing pressure fluctuations due to switching of the switching valves 42a-42d.

[0137] Also, when the eight pump elements 11a-11d, 12a-12d are sequentially connected to the boom cylinder 104a in accordance with the lever operation amount to drive the boom cylinder 104a, none of the switching valves 41a-41d, 42a-42d are switched from the first position until the required flow rate of the boom cylinder 104a can be supplied by only the first hydraulic pump 11, and the switching valves 42a-42d are switched to the second position when the required flow rate of the boom cylinder 104a cannot be supplied by only the first hydraulic pump 11. The same is true when the eight pump elements 11a-11d, 12a-12d are sequentially connected to the arm cylinder 105a in accordance with the lever operation amount to drive the arm cylinder 105a, and the switching valves 41a-41d are switched to the second position when the required flow rate of the arm cylinder 105a cannot be supplied by only the second hydraulic pump 12. Therefore, the number of times the switching valves 41a to 41d, 42a to 42d are switched when driving the boom cylinder 104a or the arm cylinder 105a can be reduced, and the durability of the switching valves 41a to 41d, 42a to 42d can be improved.

[0138] <Second embodiment> A second embodiment of the present invention will now be described.

[0139] FIG. 16 is a top view of a manifold block 40 in a pump device 10 according to the second embodiment of the present invention.

[0140] As shown in Fig. 16, the first switching valves 41a to 41d are attached to the block body 40a in a manner similar to the first embodiment such that the solenoid parts 41s protrude from one of the opposing side surfaces 40b, 40c of the block body 40a. On the other hand, the second switching valves 42a to 42d are attached to the block body 40a in a manner similar to the first embodiment such that the solenoid parts 42s protrude from the same side surface 40b to which the first switching valves 41a to 41d are attached. In this manner, in this embodiment, all of the first switching valves 41a to 41d and the second switching valves 42a to 42d are attached to the block body 40a in a manner that the solenoid parts 42s protrude from the same side surface 40b.

[0141] Figure 17 is a longitudinal cross-sectional view of the manifold block 40 taken along line XVII-XVII in Figure 16, and is a similar view to Figure 12, showing the connection state between the first inlet port and the two internal passages when the second switching valve 42a is in the initial position. Figure 18 is a similar view to Figure 13, showing the connection state between the first inlet port and the two internal passages when the second switching valve 42a is switched from the initial position to the non-initial position.

[0142] As shown in Fig. 17, when the second switching valve 42a is in the initial position, the first inlet port 66a communicates with the internal passage 44a via the L-shaped outlet port 71a, and when the second switching valve 42a is switched from the initial position to the non-initial position, the first inlet port 66a communicates with the internal passage 43a via the linear outlet port 70a as shown in Fig. 18. Although not shown, the second switching valves 42b to 42d are configured in a similar manner. As described above, in the first embodiment, the second switching valves 42a to 42d are mounted so that the solenoid portions 42s of the second switching valves 42a to 42d protrude from the side surface 40c of the manifold block 40 opposite the first switching valves 41a to 41d, so the two outlet ports have the opposite shape to the outlet ports 67a, 68a shown in Figures 11 to 13. However, in this embodiment, the second switching valves 42a to 42d are mounted so as to protrude from the same side surface 40b of the manifold block 40 as the first switching valves 41a to 41d, so the two outlet ports 70a, 71a have the same shape as the first switching valves 41a to 41d and the outlet ports 67a, 68a shown in Figures 11 to 13.

[0143] On the other hand, in the first embodiment, as described above, the second switching valves 42a to 42d have the same spool shape as the first switching valves 41a to 41d, but in this embodiment, as shown in Figures 17 and 18, the second switching valve 42a has a different spool shape from the first switching valve 41a shown in Figures 12 and 13.

[0144] FIG. 19 is a layout diagram similar to FIG. 14, showing the pump device 10 of this embodiment mounted on an upper rotating body 102.

[0145] In FIG. 19, as described above, an opening / closing cover 102c is provided on the side panel on the left side of the upper rotating body 102 to allow an operator to access the pump room in which the pump device 10 is located.

[0146] As in the first embodiment, the port block 13 (see FIG. 3) is located on the opposite side (the opening and closing cover 102c side) of the output shaft of the engine 1 of the parallel pump 30, and the manifold block 40 is mounted on the upper surface 13S of this port block 13. The manifold block 40 includes first switching valves 41a-41d and second switching valves 42a-42d, and first and second service ports 43, 44 are formed on the upper surface of the manifold block 40.

[0147] The first switching valves 41a to 41d are mounted on the manifold block 40 so that their respective solenoid portions 41s protrude from the side 40b of the block body 40a of the manifold block 40 opposite the pump shaft 14 (gear box 47) (i.e., the opposite side of the engine 1), and the second switching valves 42a to 42d are also mounted on the manifold block 40 so that their respective solenoid portions 42s protrude from the side 40b of the block body 40a of the manifold block 40 opposite the pump shaft 14 (gear box 47) (i.e., the opposite side of the engine 1).

[0148] That is, in this embodiment, the first switching valves 41a to 41d and the second switching valves 42a to 42d are attached to the block body 40a of the manifold block 40 so that their respective solenoid sections 41S, 42S protrude from the same side 40b of the block body 40a, and the same side 40b is the side opposite to the gear box 47 side on which the pump shaft 14 is located, i.e., the side on the opening / closing cover 102c side of the left side panel.

[0149] In this embodiment, the first switching valves 41a to 41d and the second switching valves 42a to 42d are mounted so that their respective solenoid sections 41S, 42S protrude from the side surface 40b of the block body 40a of the manifold block 40 on the same opening / closing cover 102c side. Therefore, during maintenance and inspection, a service technician can easily access the solenoid sections 41S, 42S of both the first switching valves 41a to 41d and the second switching valves 42a to 42d by opening the opening / closing cover 102c as shown, thereby improving maintenance workability.

[0150] <Other> In the above embodiments, the construction machine is described as a track-type hydraulic excavator, but the construction machine may be a construction machine other than a track-type hydraulic excavator (for example, a wheel-type hydraulic excavator, a hydraulic crane, a wheel loader, etc.). [Explanation of symbols]

[0151] 1 Engine (prime mover) 10 Pumping equipment 11 First hydraulic pump 12 No. 2 hydraulic pump 13 Port Block 13S Side (top) 14 Pump shaft 14a First driven shaft 14b Second driven shaft 20 Control valve 30 Parallel Pump 31 First pump port 32 Second pump port 33 First Valve Group 34 2nd Valve Group 36a, 36b First radial piston pump 37a, 37b Second radial piston pump 40 Manifold block 40a Block body 40b side 40c side 40S top 41a~41d First switching valve 41s~41s Solenoid section 42a~42d Second switching valve 42s~42s Solenoid part 43 First Service Port 44 Second Service Port 43a, 44a Internal passage 45a, 45b, 45c, 45d First discharge port 46a, 46b, 46c, 46d Second discharge port 47 Gearbox 48 Common pump casing 51 First hydraulic hose 52 No. 2 hydraulic hose 60 Piston Pump 65a~65d First inlet port 66a~66d Second inlet port 102c Opening and closing cover

Claims

1. In a pump system for a construction machine, which includes a pump array section having a first hydraulic pump and a second hydraulic pump connected via a gearbox to a pump shaft that rotates driven by a prime mover, The first hydraulic pump is configured to form a plurality of first pump elements capable of independently controlling the flow of pressurized oil discharged from a plurality of first discharge ports. The second hydraulic pump is configured to form a plurality of second pump elements capable of independently controlling the flow of pressurized oil discharged from a plurality of second discharge ports. A port block formed by the plurality of first discharge ports and the plurality of second discharge ports, configured as a shared component of the first hydraulic pump and the second hydraulic pump, The port block further comprises a plurality of first inlet ports and a plurality of second inlet ports into which pressurized oil flows from the plurality of first discharge ports and the plurality of second discharge ports, respectively, and a plurality of service ports connected to a control valve via a plurality of hydraulic hoses, and a manifold block incorporating a plurality of first switching valves that switch the flow direction of pressurized oil flowing from the plurality of first inlet ports to guide the pressurized oil flowing from the plurality of first inlet ports to one of the plurality of service ports, and a plurality of second switching valves that switch the flow direction of pressurized oil flowing from the plurality of second inlet ports to guide the pressurized oil flowing from the plurality of second inlet ports to one of the plurality of service ports, The plurality of first discharge ports and the plurality of second discharge ports of the port block are formed to open to the side of the port block. A pumping device for construction machinery, characterized in that the manifold block is coupled to the side of the port block such that the plurality of first inlet ports are aligned with the plurality of first discharge ports of the port block, and the plurality of second inlet ports are aligned with the plurality of second discharge ports of the port block.

2. In the pump device for construction machinery described in claim 1, The manifold block has an elongated rectangular parallelepiped shape and comprises a block body with opposing sides. Each of the aforementioned plurality of first switching valves and plurality of second switching valves is an electromagnetic switching valve equipped with a solenoid part at one end. The plurality of first switching valves are mounted on the block body such that the solenoid portions of the plurality of first switching valves protrude from one of the opposing sides of the block body. A pumping device for construction machinery, characterized in that the plurality of second switching valves are mounted on the block body such that the solenoid portions of the plurality of second switching valves protrude from the other of the opposing sides of the block body.

3. In the pump device for construction machinery described in claim 1, The manifold block has an elongated rectangular parallelepiped shape and comprises a block body with opposing sides. Each of the aforementioned plurality of first switching valves and plurality of second switching valves is an electromagnetic switching valve equipped with a solenoid part at one end. The plurality of first switching valves and the plurality of second switching valves are mounted on the block body such that the solenoid portions of the plurality of first switching valves and the solenoid portions of the plurality of second switching valves protrude from the same side of the opposing sides of the block body. A pump device for construction machinery, characterized in that the same one side of the block body is opposite to the pump shaft.

4. In the pump device for construction machinery described in claim 1, A pumping device for construction machinery, characterized in that the plurality of service ports of the manifold block are formed to open to the upper surface of the manifold block.

5. In the pump device for construction machinery described in claim 1, A pumping device for construction machinery, characterized in that the number of service ports of the manifold block is the same as the number of valve groups included in the control valve.

6. In the pump device for construction machinery described in claim 1, The aforementioned plurality of service ports include a first service port and a second service port, The plurality of first switching valves and the plurality of second switching valves are switchable between a first position which is an initial position and a second position which is a non-initial position. The plurality of first switching valves, in the first position, connect the plurality of first inlet ports to the first service port, and in the second position, connect the plurality of first inlet ports to the second service port. A pumping device for construction machinery, characterized in that the plurality of second switching valves, in the first position, connect the plurality of second inlet ports to the second service port, and in the second position, connect the plurality of second inlet ports to the first service port.

7. In the pump device for construction machinery described in claim 1, The first hydraulic pump and the second hydraulic pump are each connected to the pump shaft via the gearbox and have first and second driven shafts arranged parallel to each other with respect to the extension of the axis of the pump shaft. The first hydraulic pump has a plurality of first radial piston pumps arranged at intervals in the axial direction of the first driven shaft, The pumping device for construction machinery is characterized in that the second hydraulic pump has a plurality of second radial piston pumps arranged at intervals in the axial direction of the second driven shaft.

8. In the pump device for construction machinery according to claim 7, Each of the plurality of first radial piston pumps has a plurality of piston pumps arranged radially in the circumferential direction with respect to the first driven shaft, and the plurality of piston pumps of the plurality of first radial piston pumps are divided into a plurality of groups, and by combining the pressurized oil discharged from each piston pump in each group, one of the plurality of first pump elements of the first hydraulic pump is formed. The pumping device for construction machinery is characterized in that each of the plurality of second radial piston pumps has a plurality of piston pumps arranged radially in the circumferential direction with respect to the second driven shaft, and the plurality of piston pumps of the plurality of second radial piston pumps are divided into a plurality of groups, and the pressurized oil discharged from each piston pump of each group is combined to constitute one of the plurality of second pump elements of the second hydraulic pump.

9. In the pump device for construction machinery according to claim 7, A pumping device for construction machinery, characterized in that the plurality of first radial piston pumps are offset axially from each of the plurality of second radial piston pumps, and the radial range of the plurality of first radial piston pumps in the direction toward the second driven shaft extends beyond the radial range of the plurality of second radial piston pumps in the direction toward the first driven shaft.

10. In the pump device for construction machinery described in claim 1, A pump device for construction machinery, characterized in that the plurality of first discharge ports are formed on the first surface of the side portion of the port block, and the plurality of second discharge ports are formed on the first surface of the side portion of the port block or on a second surface parallel to the first surface.

11. In the pump device for construction machinery described in claim 1, The first and second hydraulic pumps are, respectively, It has at least three working chambers whose volume changes periodically in accordance with the rotation of the first and second driven shafts, Each of the working chambers of the first and second hydraulic pumps is A low-pressure valve controls the flow of pressurized oil between the working chamber and the low-pressure manifold, The system includes a high-pressure valve that controls the flow of pressurized oil between the working chamber and the high-pressure manifold, The working chambers of the first and second hydraulic pumps form the plurality of first and second pump elements, each pump element has one or more working chambers, and is connected to the high-pressure manifold which is provided in common to one or more working chambers of each pump element. A pumping device for construction machinery, further comprising a controller, the controller actively controls at least the low-pressure valve in phase correlation with the volume cycle of the working chamber, thereby determining for each volume cycle of the working chamber whether each working chamber performs an effective cycle that forms a net displacement volume of pressurized oil between the low-pressure manifold and the high-pressure manifold, or an ineffective cycle that does not form a net displacement volume of pressurized oil between the low-pressure manifold and the high-pressure manifold, and controlling the net displacement volume of the working chamber of each pump element leading to each of the plurality of discharge ports via each of the high-pressure manifolds according to the respective required flow rate of pressurized oil.

12. In the pump device for construction machinery described in claim 1, The pumping device for construction machinery is characterized in that the pump arrangement section is a parallel pump arrangement section, and the first hydraulic pump is arranged in parallel with the second hydraulic pump.

13. In the pump device for construction machinery described in claim 1, A pumping device for construction machinery, characterized in that the driven shaft of the first hydraulic pump is arranged at an inclination toward the gearbox with respect to the pump shaft, and the driven shaft of the second hydraulic pump is arranged at an inclination toward the gearbox with respect to the pump shaft.

14. Prime engine and, A pump device driven by the aforementioned prime mover, Multiple actuators driven by pressurized oil discharged from the pump device, The system includes a plurality of directional control valves that control the flow of pressurized oil supplied from the pump device to the plurality of actuators, The pump device is A hydraulic circuit system for a construction machine comprising a pump array section having a first hydraulic pump and a second hydraulic pump connected via a gearbox to a pump shaft that rotates driven by the aforementioned prime mover, The first hydraulic pump is configured to form a plurality of first pump elements capable of independently controlling the flow of pressurized oil discharged from a plurality of first discharge ports. The second hydraulic pump is configured to form a plurality of second pump elements capable of independently controlling the flow of pressurized oil discharged from a plurality of second discharge ports. A port block formed by the plurality of first discharge ports and the plurality of second discharge ports, configured as a shared component of the first hydraulic pump and the second hydraulic pump, The port block further comprises a plurality of first inlet ports and a plurality of second inlet ports into which pressurized oil flows from the plurality of first discharge ports and the plurality of second discharge ports, respectively, and a plurality of service ports connected to a control valve via a plurality of hydraulic hoses, and a manifold block incorporating a plurality of first switching valves that switch the flow direction of pressurized oil flowing from the plurality of first inlet ports to guide the pressurized oil flowing from the plurality of first inlet ports to one of the plurality of service ports, and a plurality of second switching valves that switch the flow direction of pressurized oil flowing from the plurality of second inlet ports to guide the pressurized oil flowing from the plurality of second inlet ports to one of the plurality of service ports, The plurality of first discharge ports and the plurality of second discharge ports of the port block are formed to open to the side of the port block. The manifold block is coupled to the side of the port block such that the plurality of first inlet ports are aligned with the plurality of first discharge ports of the port block, and the plurality of second inlet ports are aligned with the plurality of second discharge ports of the port block. A hydraulic circuit system for construction machinery, characterized in that the multiple service ports of the manifold block are connected via multiple pipes to a control valve in which the multiple directional control valves are housed within a valve housing.

15. In the hydraulic circuit system for construction machinery according to claim 14, The multiple service ports of the manifold block are connected to the multiple pump ports provided on the control valve via the multiple pipes. A hydraulic circuit system for construction machinery, characterized in that the number of service ports and the number of pump ports are the same as the number of first and second hydraulic pumps in the pump array.

16. In the hydraulic circuit system for construction machinery according to claim 14, The plurality of actuators include a specific first actuator and a specific second actuator that are operated relatively frequently. The plurality of directional control valves are divided within the control valve into a first valve group including two directional control valves for a specific first actuator, and a second valve group including two directional control valves for a specific second actuator. The plurality of service ports include first and second service ports, and the plurality of piping includes first and second piping, A hydraulic circuit system for construction machinery, characterized in that the control valve has first and second pump ports connected to the first and second valve groups, respectively, and the first and second pump ports are connected to the first and second service ports via the first and second piping.

17. In the hydraulic circuit system for construction machinery according to claim 14, The plurality of service ports include the first and second service ports, The plurality of first and second switching valves are switchable between a first position, which is the initial position, and a second position, which is a non-initial position. The plurality of first switching valves, in the first position, connect the plurality of first discharge ports to the first service port, and in the second position, connect the plurality of first discharge ports to the second service port. A hydraulic circuit system for construction machinery, characterized in that the plurality of second switching valves communicate the plurality of second discharge ports to the second service port in the first position, and the plurality of second discharge ports to the first service port in the second position.

18. In the hydraulic circuit system for construction machinery according to claim 14, The plurality of first and second pump elements of the first and second hydraulic pumps are each four first and second pump elements, and the plurality of first and second discharge ports are each four first and second discharge ports. A hydraulic circuit system for construction machinery, characterized in that the plurality of first and second switching valves in the manifold block are each four first and second switching valves.

19. In the hydraulic circuit system for construction machinery according to claim 14, The first hydraulic pump and the second hydraulic pump are each connected to the pump shaft via the gearbox and have first and second driven shafts arranged parallel to each other with respect to the extension of the axis of the pump shaft. The first hydraulic pump has a plurality of first radial piston pumps arranged at intervals in the axial direction of the first driven shaft, Each of the plurality of first radial piston pumps has a plurality of piston pumps arranged radially with respect to the first driven shaft, and the plurality of piston pumps are divided into a plurality of groups, and the pressurized oil discharged from each piston pump within each group is combined to form one of the plurality of first pump elements of the first hydraulic pump. The second hydraulic pump has a plurality of second radial piston pumps arranged at intervals in the axial direction of the second driven shaft, A hydraulic circuit system for construction machinery, characterized in that each of the plurality of second radial piston pumps has a plurality of piston pumps arranged radially with respect to the second driven shaft, the plurality of piston pumps are divided into a plurality of groups, and the pressurized oil discharged from each piston pump within each group is combined to form one of the plurality of second pump elements of the second hydraulic pump.

20. In the hydraulic circuit system for construction machinery according to claim 14, A hydraulic circuit system for construction machinery, characterized in that the plurality of first discharge ports are formed on the first surface of the side portion of the port block, and the plurality of second discharge ports are formed on the first surface of the side portion of the port block or on a second surface parallel to the first surface.

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