Valve block and hydraulic pump device

Abstract

The technical problem to be solved is to provide the valve block of the hydraulic pump device and the hydraulic pump device provided with the valve block, which can inhibit working liquid from leaking from butt joint surfaces where two pump parts are respectively matched with the valve block. The technical means for solving the problem is that the valve block is arranged between two variable capacity type pump parts in a hydraulic pump device in which the two pump parts are arranged in a first direction, and the valve block is provided with: a block main body in which regulator control flow paths are formed, the regulator control flow paths being respectively connected to regulators provided in the pump parts; and check valves provided in the block main body so as to be interposed in the regulator control flow paths, respectively. The check valve is inserted into the block body from one side in a second direction orthogonal to the first direction.

Description

Technical Field

[0001] The present disclosure relates to a valve block disposed between two pump units in a hydraulic pump device in which two pump units are arranged in parallel, and to a hydraulic pump device including the valve block. Background Art

[0002] As a hydraulic pump device, for example, the pump device of Patent Document 1 is known. In the pump device of Patent Document 1, two pump units are arranged in a form of being arranged on a shaft member shared by each other. A valve block is arranged between the two pump units. In addition, the pump unit is a variable capacity swash plate pump, and the tilting angle of the swash plate is changed by a regulator. Thus, the pump unit can change the discharge capacity.

[0003] Prior art literature:

[0004] Patent Literature:

[0005] Patent Document 1: Japanese Patent Application Publication No. 2007-51553. Utility Model Content

[0006] Problems to be solved by the utility model:

[0007] In the pump device of Patent Document 1, each regulator operates, for example, as follows to change the tilting angle of the swash plate. That is, the regulator has a servo piston, and the control pressure and the selection pressure act on the servo piston in a mutually opposing manner. The servo piston strokes to a position corresponding to the pressure difference between the control pressure and the selection pressure, and changes the tilting angle of the swash plate by the stroke. The control pressure is controlled by a directional control valve included in the regulator. On the other hand, the selection pressure selects a high pressure from the input pressure and the discharge pressure input from the pilot pump.

[0008] In such a pump device, a plurality of check valves are provided in order to select a high pressure from an input pressure and a discharge pressure. The plurality of check valves are arranged in the pump device, for example, as follows. That is, the plurality of check valves are arranged on the valve block, and the valve block is respectively arranged on the butt joint surfaces where the two pump parts are butt jointed with each other. Therefore, when the butt joint surfaces are separated from each other, etc., the working fluid will leak from the check valve.

[0009] Therefore, an object of the present disclosure is to provide a valve block and a hydraulic pump device including the valve block, which can suppress leakage of working fluid from the butt joint surfaces where two pump parts and the valve block respectively cooperate with each other.

[0010] Means of solving the problem:

[0011] The valve block disclosed in the present invention is a valve block interposed between two variable capacity pump parts in a hydraulic pump device arranged along a first direction, and comprises: a block body, which is formed with a regulator control flow path respectively connected to the regulators provided in the pump parts; and a check valve, which is provided on the block body in the form of being respectively interposed in the regulator control flow path; the check valve is inserted from one side of a second direction orthogonal to the first direction and is provided on the block body.

[0012] According to the valve block disclosed in the present invention, the check valve is inserted from one side of the second direction and is arranged on the block body. Therefore, the number of check valves arranged on the docking surfaces of the valve block that are respectively docked with the pump parts is reduced. As a result, it is possible to suppress leakage of working fluid from the check valves arranged on the docking surfaces due to the docking surfaces being separated from the respective pump parts.

[0013] The hydraulic pump device disclosed in the present invention comprises: the aforementioned valve block; two variable capacity type pump units arranged in a first direction with the valve block interposed therebetween; and the regulators respectively arranged in the first direction of the pump units to adjust the discharge capacities of the respective pump units.

[0014] According to the hydraulic pump device of the present disclosure, it is possible to realize a hydraulic pump device that achieves the above-mentioned functions.

[0015] Utility model effect:

[0016] According to the present disclosure, leakage of the working fluid from the butting surface can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a perspective view showing a hydraulic pump device according to an embodiment of the present disclosure;

[0018] Figure 2 Observed from the rear Figure 1 Rear view of the hydraulic pump;

[0019] Figure 3 It is shown Figure 1 Circuit diagram of the hydraulic pump device;

[0020] Figure 4 It is shown Figure 1 A three-dimensional diagram of the valve block provided;

[0021] Figure 5 So Figure 2 The section line VV shown cuts through the valve block to show a partial cross-sectional view;

[0022] Figure 6 Observed from above Figure 4 A top view of the valve block;

[0023] Figure 7 It is shown in an enlarged manner Figure 2 An enlarged cross-sectional view of a region X of a hydraulic pump device;

[0024] Explanation of symbols:

[0025] 1 Hydraulic pump unit

[0026] 2 Valve block

[0027] 3R, 3L pump unit

[0028] 4R, 4L Regulator

[0029] 21 blocks of body

[0030] 21Rb, 21Lb docking surface

[0031] 22a~22b Check valve

[0032] 28R, 28L Regulator control flow path

[0033] 28Ra, 28La first flow path part

[0034] 28Rb, 28Lb Second flow path

[0035] 28Rc, 28Lc Third flow path

[0036] 31L, 31R valve mounting section. DETAILED DESCRIPTION

[0037] Hereinafter, the hydraulic pump device 1 and the valve block 2 provided therewith according to the embodiment of the present disclosure will be described with reference to the above-mentioned drawings. In addition, the directional concepts used in the following description are used for the convenience of description, and the structural orientation of the utility model is not limited to the direction. Furthermore, the hydraulic pump device 1 and the valve block 2 described below are only one embodiment of the present disclosure. Therefore, the present disclosure is not limited to the embodiment, and additions, deletions, and changes can be made within the scope of the utility model without departing from the main purpose of the utility model.

[0038] <Hydraulic pump unit>

[0039] Figure 1 The hydraulic pump device 1 shown is mounted on a hydraulic machine such as an industrial machine or a construction machine. The hydraulic pump device 1 is driven by a tank 5 (see Figure 3 ) sucks in working fluid and discharges it. The hydraulic pump device 1 is connected to hydraulic actuators (for example, hydraulic cylinders and hydraulic motors) provided in industrial machinery and construction machinery. The working fluid discharged from the hydraulic pump device 1 is supplied to each hydraulic actuator. As a result, the hydraulic actuator operates. Figure 2As shown, the hydraulic pump device 1 is a so-called tandem pump, which is a composite pump device composed of two pump units 3R and 3L described later. The hydraulic pump device 1 includes two pump units 3R and 3L, regulators 4R and 4L, and a valve block 2. In the hydraulic pump device 1, the two pump units 3R and 3L are arranged in an axial direction described later, and a valve block 2 is interposed between them. The structure of the hydraulic pump device 1 is described in detail below.

[0040] <Pump unit>

[0041] The pump units 3R and 3L are respectively supplied from the tank 5 (see Figure 3 ) sucks in the working fluid and discharges it. The pump units 3R, 3L are arranged in an axial direction as a first direction at intervals from each other. Here, the axial direction refers to the direction in which the shaft member 11 extends, and in the present embodiment, it is the left-right direction. To explain in more detail, the pump units 3R, 3L share a common shaft member 11. Moreover, the pump units 3R, 3L are arranged in an axial direction at intervals from each other along the shaft member 11. The pump units 3R, 3L are, for example, variable capacity swash plate type piston pumps. The two pump units 3R, 3L are adjusted by changing the swash plates 10R, 10L (see Figure 3 The discharge capacity can be changed by adjusting the tilt angle of the hydraulic circuit.

[0042] The pump sections 3R and 3L are described in further detail below. In addition, the pump sections 3R and 3L have the same structure as each other and are symmetrically (point symmetrically in the present embodiment). Therefore, the following description will focus on the structure of the pump section 3R on one side. Moreover, for the structure of the pump section 3L on the other side, the symbol of the same structure as the pump section 3R on one side is replaced from "R" to "L", and the detailed description is omitted.

[0043] The pump section 3R on one side includes a housing 12R, the aforementioned shaft member 11, and swash plates 10R, 10L. In addition, the housing 12R also contains a cylinder body and a piston, etc., which are not shown in the figure. The housing 12R is open on both sides in the axial direction. The shaft member 11 passes through the housing 12R. That is, one end of the shaft member 11 protrudes outward from the opening 12Ra of the housing 12R, and the other end side extends into the housing 12L on the other side. Moreover, the shaft member 11 is rotatably supported on each housing 12R, 12L. In addition, one end of the shaft member 11 is connected to a driving source (for example, at least one of an engine and an electric motor) E (see Figure 3 hydraulic circuit).

[0044] Furthermore, a cylinder body is provided on the shaft member 11 so as to be non-rotatable relative to it. A plurality of cylinder holes are formed on one end face of the cylinder body. A piston is inserted into each cylinder hole so as to be reciprocating. The swash plates 10R and 10L are arranged to face one end face of the cylinder body and are inclined, and the pistons are supported on the swash plates 10R and 10L via sliding shoes. The pistons slide and rotate on the swash plates around the axis of the shaft member 11, that is, the rotation axis L1, via the sliding shoes. Therefore, in the pump units 3R and 3L, when the shaft member 11 is rotated, the pistons reciprocate in the cylinder holes.

[0045] <Regulator>

[0046] The regulators 4R and 4L are provided at the pump parts 3R and 3L, respectively. To explain in more detail, the regulators 4R and 4L are provided at one side of the second direction (the upper side in the present embodiment) on each pump part 3R and 3L. Moreover, the regulators 4R and 4L are arranged point-symmetrically in the present embodiment. Moreover, the regulators 4R and 4L change the tilting angle of the swash plates 10R and 10L of the pump parts 3R and 3L, respectively. The regulators 4R and 4L include servo pistons 13R and 13L, respectively. In addition, the regulators 4R and 4L each include a directional control valve 14R and 14L and an electromagnetic proportional control valve 15R and 15L, respectively.

[0047] The servo pistons 13R and 13L are accommodated in the upper side of the housings 12R and 12L of the pump units 3R and 3L. The servo pistons 13R and 13L are accommodated in a form that allows them to move in the axial direction. Figure 2 As shown in FIG. 1 , the selection pressure and the control pressure described in detail later act on the servo pistons 13R and 13L in a mutually opposing manner. Furthermore, the servo pistons 13R and 13L are stroked to positions corresponding to the pressure difference between the selection pressure and the control pressure. In addition, the servo pistons 13R and 13L are connected to the swash plates 10R and 10L, respectively, and the tilt angles of the swash plates 10R and 10L are changed by the strokes (see FIG. 1 ). Figure 3 The servo pistons 13R and 13L have position adjustment parts (e.g., adjustment screws) 13Ra and 13La at one end thereof. The positions of the servo pistons 13R and 13L are adjusted by operating the position adjustment parts 13Ra and 13La (in this embodiment, by turning the adjustment screws). One end of the servo pistons 13R and 13L passes through the valve mounting parts 31R and 31L described in detail later and protrudes outward.

[0048] Directional control valves 14R and 14L are provided on the upper part of housings 12R and 12L of pump units 3R and 3L. Directional control valves 14R and 14L output control pressure to servo pistons 13R and 13L. In more detail, a selection pressure is input into the directional control valves 14R and 14L. In addition, the directional control valves 14R and 14L operate the slide valves 14Ra and 14La (see FIG. 1 ) according to the input pilot pressure. Figure 3As a result, the directional control valves 14R and 14L output a control pressure that controls the selection pressure to a pressure corresponding to the pilot pressure.

[0049] The electromagnetic proportional control valves 15R and 15L are provided in the upper part of the housings 12R and 12L of the pump units 3R and 3L. The electromagnetic proportional control valves 15R and 15L output pilot pressures corresponding to the input control signals to the direction control valves 14R and 14L, respectively. Thus, the electromagnetic proportional control valves 15R and 15L can move the servo pistons 13R and 13L to positions corresponding to the input control signals, and adjust the tilting angles of the swash plates 10R and 10L. That is, the electromagnetic proportional control valves 15R and 15L control the tilting angles of the swash plates 10R and 10L to angles corresponding to the input control signals. In addition, the control signal is an electrical signal output from a control device or the like not shown in the figure.

[0050] <Valve block>

[0051] like Figure 1 and Figure 2 As shown, the valve block 2 is interposed between the two pump sections 3R and 3L. To explain in more detail, the valve block 2 is arranged in the axial direction together with the two pump sections 3R and 3L, and is configured to be sandwiched by the two pump sections 3R and 3L. Moreover, the valve block 2 and the two pump sections 3R and 3L are fastened by a plurality of fastening members 16, respectively. In the present embodiment, each pump section 3R and 3L is fastened to the valve block 2 by four fastening members 16, respectively. When viewed from one side or the other side of the axial direction, each fastening member 16 is respectively arranged at the four corners of the valve block 2, and fastens the valve block 2 and each pump section 3R and 3L, respectively. In addition, the valve block 2 includes a block body 21 and a plurality of check valves 22a to 22d. In addition, in the present embodiment, the valve block 2 includes four check valves 22a to 22d.

[0052] like Figure 4 As shown, the block body 21 is formed into a roughly rectangular parallelepiped shape. The block body 21 is arranged between the two pump parts 3R and 3L in such a manner that the docking surfaces 21Rb and 21Lb, which are the two axial side surfaces (i.e., the left and right side surfaces), abut against the axial end surfaces of each pump part 3R and 3L, respectively. To explain in more detail, in one pump part 3R, the left end surface located on the opposite side of the right end surface from which the shaft member 11 protrudes, abuts against the docking surface 21Rb on the right side of the block body 21. In the other pump part 3L, the right end surface abuts against the docking surface 21Lb on the left side of the block body 21. In addition, the block body 21 has valve mounting parts 31R and 31L. In addition, on the block body 21, for example, two plate fixing parts 25, a discharge passage 26, and a suction passage 27 (see Figure 5 ), two regulator control flow paths 28R, 28L and two pilot pressure supply flow paths 29R, 29L.

[0053] The valve mounting parts 31R and 31L are respectively formed on both sides in the left-right direction in a form adjacent to the regulators 4R and 4L. To explain in more detail, the block body 21 forms left and right side edges at the upper part of the block body 21, that is, the top 21a of the block body 21. Moreover, the valve mounting parts 31R and 31L are formed so that the side edges in the axial direction protrude upward. In addition, the valve mounting parts 31R and 31L extend in the front-to-back direction. The valve mounting parts 31R and 31L each have an insertion hole 31a. The insertion hole 31a is formed on the valve mounting parts 31R and 31L, for example, in the middle part in the front-to-back direction. Moreover, the insertion hole 31a is penetrated by the servo pistons 13L and 13R, and the servo pistons 13L and 13R make one end (that is, the position adjustment parts 13Ra and 13La) protrude outward. As will be described in detail later, a part of the regulator control flow paths 28R and 28L is formed in the valve mounting portions 31R and 31L formed in this way, and a plurality of check valves 22a to 22d are mounted on each of them.

[0054] The two plate fixing parts 25 are respectively formed on the docking surfaces 21Rb and 21Lb on the left and right sides of the block body 21. For example, the two plate fixing parts 25 are arranged below the valve mounting parts 31R and 31L. In addition, the plate fixing part 25 formed on the docking surface 21Lb on the left side is not shown. Each plate fixing part 25 is respectively embedded in and fixed with a valve plate 17. A suction port 17a and a discharge port 17b are respectively formed on the valve plate 17. The suction port 17a and the discharge port 17b are respectively connected to each pump part 3R and 3L. Explaining in more detail, the suction port 17a and the discharge port 17b correspond to the multiple cylinder holes of each pump part 3R and 3L, and are formed into a circular arc shape centered on the rotation axis L1. Each cylinder hole is alternately connected to the suction port 17a and the discharge port 17b when the cylinder body rotates.

[0055] The discharge passage 26 is a passage through which the working fluid discharged from each pump unit 3R, 3L flows. In more detail, the discharge passage 26 is connected to the discharge port 17b of each valve plate 17. Figure 5 The discharge port 17b shown in FIG. 1 extends along one side of the third direction and opens at one side of the block body 21 in the third direction (see also FIG. 1 ). Figure 4 ). The third direction is a direction orthogonal to the first direction and the second direction, and is the front-back direction in this embodiment. Moreover, one side of the third direction is the front, and one side of the third direction is the front surface.

[0056] The suction passage 27 is from the tank 5 (see Figure 3 ) is a passage for introducing working fluid. To explain in more detail, the suction passage 27 is connected to the suction port 17a of each valve plate 17. The suction passage 27 extends from the suction port 17a to the other side along the third direction and opens at the other side of the block body 21 in the third direction (not shown). In this embodiment, the other side in the third direction is the rear, and the other side in the third direction is the rear surface.

[0057] The two regulator control flow paths 28R and 28L are as follows Figure 6 As shown, the regulator control flow paths 28R and 28L are formed in the block body 21. In the present embodiment, the regulator control flow paths 28R and 28L are formed on the upper side of the block body 21 (in the present embodiment, the upper side of each passage 26 and 27). The two regulator control flow paths 28R and 28L are connected to the regulators 4L and 4R, respectively. In addition, the regulator control flow paths 28R and 28L are connected to the pump units 3R and 3L, respectively (see also Figure 7 ). To explain in more detail, each regulator control flow path 28R, 28L is connected to the discharge port 17b, and is connected to the pump unit 3R, 3L via the discharge port 17b (see Figure 5 ). In addition, the regulator control flow paths 28R and 28L are as follows Figure 6 As shown, they are connected to the input port 28a respectively. The input port 28a is formed on the rear surface of the block body 21. The input port 28a is connected to a pilot pump (not shown), for example. The hydraulic pressure discharged from the pilot pump, that is, the input pressure, is input into the input port 28a. As a result, each regulator control flow path 28R, 28L can respectively introduce the discharge pressure and input pressure of the pump unit 3R, 3L into each regulator 4L, 4R. Describing in more detail, each regulator control flow path 28R, 28L has a first to third flow path section 28Ra~28Rc, 28La~28Lc, respectively.

[0058] The discharge pressure of each pump unit 3R, 3L is introduced into each first flow path portion 28Ra, 28La. The first flow path portions 28Ra, 28La are connected to each pump unit 3R, 3L. In more detail, the first flow path portions 28Ra, 28La are connected to the discharge port 17b, respectively, and are connected to each pump unit 3R, 3L via the discharge port 17b (see Figure 5 ). In addition, the first flow path portions 28Ra and 28La extend upward from each discharge port 17b in the present embodiment. In addition, the first flow path portions 28Ra and 28La are arranged on the front side of the insertion hole 31a on the valve mounting portions 31R and 31L (see Figure 6 ). Furthermore, the first flow path portions 28Ra and 28La penetrate the valve mounting portions 31R and 31L and have check valve insertion portions 32Ra and 32La on the upper side, respectively. The check valve insertion portions 32Ra and 32La are open on the upper surfaces of the valve mounting portions 31R and 31L.

[0059] Figure 6 The second flow path portions 28Rb and 28Lb shown are introduced with input pressure. The second flow path portions 28Rb and 28Lb are connected to the input port 28a. In more detail, the second flow path portions 28Rb and 28Lb share a portion with each other, that is, they have a common portion 28b. The common portion 28b is connected to the input port 28a. Figure 7 As shown, each second flow path portion 28Rb, 28Lb branches from the common portion 28b toward each pump portion 3L, 3R. The second flow path portion 28Rb, for example, branches from the common portion 28b and then extends in the right direction to reach the valve mounting portion 31R. Also, the second flow path portion 28Lb, for example, branches from the common portion 28b and then extends in the left direction to reach the valve mounting portion 31L (see also Figure 6 ). The second flow path portions 28Rb and 28Lb are arranged on the rear side of the insertion hole 31a on the valve mounting portions 31R and 31L (see Figure 6 ). In addition, the second flow path portions 28Rb and 28Lb extend upward in the form of penetrating the valve mounting portions 31R and 31L, respectively. In addition, the second flow path portions 28Rb and 28Lb have check valve insertion portions 32Ra and 32La on the upper side, respectively. The check valve insertion portions 32Ra and 32La are open on the upper surfaces of the valve mounting portions 31R and 31L.

[0060] The third flow path portions 28Rc and 28Lc are as follows Figure 6 As shown, it is connected to the first flow path portion 28Ra, 28La, the second flow path portion 28Rb, 28Lb and the regulator 4L, 4R. Describing in more detail, the third flow path portion 28Rc, 28Lc has connecting portions 28Rd, 28Ld and connecting portions 28Re, 28Le, respectively. The connecting portions 28Rd, 28Ld are formed on the valve mounting portions 31R, 31L, respectively. The connecting portion 28Rd is connected to the two flow path portions 28Ra, 28Rb, respectively, and the connecting portion 28Ld is connected to the two flow path portions 28La, 28Lb, respectively. In the present embodiment, the connecting portion 28Rd is connected to the check valve insertion portions 32Ra, 32Rb formed on the valve mounting portion 31R. Furthermore, the connecting portion 28Ld is connected to the check valve insertion portions 32La, 32Lb formed on the valve mounting portion 31L (see Figure 5 ).

[0061] like Figure 7 As shown in FIG. 1 , the connection parts 28Re and 28Le are formed on the valve mounting parts 31R and 31L, respectively. The connection parts 28Re and 28Le are connected to the regulators 4L and 4R, respectively. In the present embodiment, the connection parts 28Re and 28Le are connected to the servo pistons 13R and 13L and the directional control valves 14R and 14L, respectively, via the flow paths 12Rb and 12Lb formed on the housings 12R and 12L, respectively. Furthermore, the connection parts 28Re and 28Le are connected to the communication parts 28Rd and 28Ld, respectively. In the present embodiment, the connection part 28Re is as shown in FIG. Figure 6As shown, the connecting portion 28Re is connected to the check valve insertion portion 32Rb of the second flow path portion 28Rb, and is connected to the communication portion 28Rd via the check valve insertion portion 32Rb. In addition, the connecting portion 28Re extends to the right from the check valve insertion portion 32Rb. On the other hand, the connecting portion 28Le is connected to the check valve insertion portion 32La of the first flow path portion 28La, and is connected to the communication portion 28Ld via the check valve insertion portion 32La (see also Figure 7 ). The connection portion 28Le extends leftward from the check valve insertion portion 32Lb. In addition, the connection portions 28Re and 28Le are opened at the left and right sides of the block body 21, respectively, and are connected to the flow paths 12Rb and 12Lb of the housings 12R and 12L, respectively.

[0062] The two pilot pressure supply passages 29R and 29L are as follows Figure 6 As shown, it is formed on the block body 21. The pilot pressure supply flow paths 29R, 29L are connected to the electromagnetic proportional control valves 15R, 15L, respectively. Furthermore, the pilot pressure supply flow paths 29R, 29L are connected to the input port 28a, and are connected to the pilot pump (not shown) via the input port 28a. In the present embodiment, the pilot pressure supply flow paths 29R, 29L are connected to the second flow path portions 28Rb, 28Lb, respectively, and are connected to the input port 28a via the second flow path portions 28Rb, 28Lb. Furthermore, the pilot pressure supply flow paths 29R, 29L extend from the second flow path portions 28Rb, 28Lb to the left and right side surfaces of the block body 21, respectively. Moreover, each pilot pressure supply flow path 29R, 29L is connected to the electromagnetic proportional control valves 15R, 15L via the pilot passages 12Rc, 12Lc formed on the housings 12R, 12L, respectively (see Figure 7 ).

[0063] The check valves 22a to 22d are provided on the block body 21 (see FIG. 2 ) so as to be interposed between the respective regulator control flow passages 28R and 28L. Figure 5 and Figure 7 ). To explain in more detail, the check valves 22a and 22c are respectively disposed in the first flow path portions 28Ra and 28La, and the check valves 22b and 22d are respectively disposed in the second flow path portions 28Rb and 28Lb. Furthermore, the check valves 22a and 22b are respectively disposed in the valve mounting portion 31R of the block body 21, and the check valves 22c and 22d are respectively disposed in the valve mounting portion 31L of the block body 21.

[0064] The check valves 22a to 22d are inserted into the valve mounting portions 31R and 31L from above (see, for example, Figure 5). To explain in more detail, the check valves 22a to 22d are formed into a cylindrical shape, for example. The check valves 22a and 22c are respectively inserted into the check valve insertion portions 32Ra and 32La of the first flow path portions 28Ra and 28La, and the check valves 22a and 22c are respectively inserted into the check valve insertion portions 32Rb and 32Lb of the second flow path portions 28Rb and 28Lb. Moreover, the check valve insertion portions 32Ra, 32Rb, 32La, and 32Lb are respectively closed by the plug 33, so that the check valves 22a to 22d are arranged in each flow path portion 28Ra, 28Rb, 28La, and 28Lb.

[0065] The check valves 22a and 22b allow the flow of the working fluid from the first flow path 28Ra and the second flow path 28Rb to the third flow path 28Rc. In addition, the check valves 22c and 22d allow the flow of the working fluid from the first flow path 28La and the second flow path 28Lb to the third flow path 28Lc. Therefore, the input pressure and the discharge pressure are selected to be high pressure by the check valves 22a to 22d, and the selected pressure after selecting the high pressure is output to the servo pistons 13R and 13L and the directional control valves 14R and 14L, respectively.

[0066] <About the operation of the hydraulic pump unit>

[0067] In the hydraulic pump device 1 thus configured, when the shaft member 11 is rotated by the driving source E, the cylinder bodies of the pump units 3R and 3L rotate. As a result, the plurality of pistons rotate about the axis on the swash plates 10R and 10L and reciprocate in the cylinder bores. As a result, the working fluid is sucked into the cylinder bores through the suction passage 27 and the suction port 17a, and then the working fluid is discharged from the cylinder bores to the discharge passage 26 through the discharge port 17b.

[0068] In the hydraulic pump device 1, the discharge capacity of each pump unit 3R and 3L is controlled as follows. For example, in the pump unit 3R, the discharge pressure and the input pressure are respectively introduced into the first flow path 28Ra and the second flow path 28Rb of the regulator control flow path 28R. The check valves 22a and 22b select the higher pressure between the discharge pressure and the input pressure. And the selected pressure is introduced into the servo piston 13R and the directional control valve 14R.

[0069] A pilot pressure corresponding to the control signal is inputted to the directional control valve 14R from the electromagnetic proportional control valve 15R. As a result, the directional control valve 14R controls the selection pressure to the control pressure corresponding to the control signal and outputs it to the servo piston 13R. The selection pressure and the control pressure act on the servo piston 13R in directions opposing each other, and the servo piston 13R strokes to a position corresponding to the pressure difference between the selection pressure and the control pressure. As a result, the pump unit 3R controls the tilting angle of the swash plate 10R to an angle corresponding to the control signal.

[0070] Similarly, in the pump unit 3L, one of the discharge pressure and the input pressure is selected as a high pressure through the check valves 22b and 22d and introduced into the servo piston 13L and the direction control valve 14L. Then, the direction control valve 14L controls the selected pressure to a control pressure corresponding to the control signal and outputs it to the servo piston 13L. Thus, the pump unit 3L also controls the tilt angle of the swash plate 10R to an angle corresponding to the control signal.

[0071] In the valve block 2 of the present embodiment, four check valves 22a to 22d are inserted from the upper side and provided in the block body 21. Therefore, the number of check valves arranged on the butt joint surfaces 21Rb and 21Lb where the pump parts 3R and 3L are butted against each other in the valve block 2 can be reduced. Thus, it is possible to suppress leakage of the working fluid from the check valves arranged on the butt joint surfaces 21Rb and 21Lb due to the butt joint surfaces 21Rb and 21Lb being separated from the pump parts 3R and 3L.

[0072] In the valve block 2 of the present embodiment, each of the regulator control flow paths 28R and 28L has a third flow path portion 28Rc and 28Lc connected to the first flow path portion 28Ra and 28La, the second flow path portion 28Rb and 28Lb, and the regulator 4R and 4L, respectively. In addition, the check valves 22a to 22d are respectively disposed on the first flow path portion 28Ra and 28La and the second flow path portion 28Rb and 28Lb of each of the regulator control flow paths 28R and 28L. Therefore, the high pressure is selected from the discharge pressure and the input pressure by the check valves 22a to 22d disposed on the first flow path portion 28Ra and 28La and the second flow path portion 28Rb and 28Lb, and is introduced into the regulator 4R and 4L, respectively, through the third flow path portion 28Rc and 28Lc. It is possible to suppress the check valves 22a to 22d having such a function from being disposed on the docking surfaces 21Rb and 21Lb.

[0073] In the valve block 2 of the present embodiment, the valve mounting portions 31R and 31L are respectively formed on the left and right sides in a form adjacent to the regulators 4R and 4L, and are formed to protrude upward on the block body 21. Furthermore, the check valves 22a to 22d are inserted into the valve mounting portions 31R and 31L from the upper side. Therefore, the check valves 22a to 22d can be arranged on the upper side, so the check valves 22a to 22d can be easily inserted into the block body 21.

[0074] Furthermore, in the valve block 2 of the present embodiment, the hydraulic pump device 1 that achieves the above-mentioned functions can be realized.

[0075] <About other implementation methods>

[0076] In the hydraulic pump device 1 of the present embodiment, the number of the check valves 22a to 22d provided in the valve block 2 is four, but may be five or more. Furthermore, all the check valves 22a to 22d do not necessarily need to be formed at places other than the butting surfaces 21Rb and 21Lb. The flow paths formed on the valve block 2 are not limited to the regulator control flow paths 28R and 28L and the pilot pressure supply flow paths 29R and 29L, and flow paths other than these may be formed. Furthermore, the shapes of the regulator control flow paths 28R and 28L and the pilot pressure supply flow paths 29R and 29L are not limited to the aforementioned shapes.

[0077] In the hydraulic pump device 1 of this embodiment, the check valve is inserted from above and provided in the block body 21, but it may be inserted from the front, rear or bottom. In the valve block 2, the valve mounting portions 31R and 31L do not necessarily need to protrude upward.

[0078] <Exemplary embodiment>

[0079] The valve block of the first aspect is a valve block interposed between two variable capacity pump sections in a hydraulic pump device arranged along a first direction, and comprises: a block body, which is formed with a regulator control flow path respectively connected to the regulators provided in the pump sections; and a check valve, which is provided on the block body in the form of being respectively interposed in the regulator control flow path; the check valve is inserted from one side of a second direction orthogonal to the first direction and is provided on the block body.

[0080] According to the above aspect, the check valve is inserted from one side of the second direction and is provided in the block body. Therefore, the number of check valves arranged on the docking surfaces of the valve block that are respectively docked with the pump parts is reduced. Thus, it is possible to suppress leakage of working fluid from the check valves arranged on the docking surfaces due to the docking surfaces being separated from the respective pump parts 3R, 3L.

[0081] The valve block of the second aspect is provided with a plurality of the check valves in the valve block 2 of the first aspect, and each of the flow paths for controlling the regulator respectively comprises: a first flow path portion for guiding the discharge pressure of the pump portion; a second flow path portion for guiding a specified input pressure; and a third flow path portion connected to the first flow path portion, the second flow path portion and the regulator, and the plurality of check valves are respectively arranged on the first flow path portion and the second flow path portion of each of the flow paths for controlling the regulator to allow flow to the third flow path portion.

[0082] According to the above aspect, each regulator control flow path has a third flow path portion connected to the first flow path portion, the second flow path portion and the regulator. In addition, a plurality of check valves are respectively disposed on the first flow path portion and the second flow path portion of each regulator control flow path. Therefore, the high pressure is selected from the discharge pressure and the input pressure by the check valves respectively disposed on the first flow path portion and the second flow path portion, and is respectively guided to the regulator via the third flow path portion. It is possible to suppress the configuration of the check valve having such a function on the docking surface.

[0083] The valve block of the third aspect is two types of valve blocks of the first or second aspect, and has a plurality of the check valves, the block body includes a valve mounting portion, the valve mounting portion is formed on both sides of the first direction in a form adjacent to the regulator arranged on one side of the second direction of the pump part, the valve mounting portion is formed on the block body to protrude to one side of the second direction, and the plurality of check valves are inserted into each of the valve mounting portions from one side of the second direction.

[0084] According to the above aspect, the valve mounting portion is formed on both sides of the first direction in a form adjacent to the regulator, and is formed on the block body to protrude in one side of the second direction. In addition, the plurality of check valves are inserted into the valve mounting portion from one side of the second direction. Therefore, the plurality of check valves can be arranged close to one side of the second direction, so the check valves can be easily inserted into the block body.

[0085] The hydraulic pump device of the fourth aspect comprises: a valve block of any one of the first to third aspects; two variable capacity type pump units arranged in a first direction with the valve block interposed therebetween; and regulators respectively arranged in the first direction of the pump units for adjusting the respective discharge capacities of the pump units.

[0086] According to the above aspect, it is possible to realize the hydraulic pump device that achieves the above-mentioned functions.

Claims

1. A valve block, characterized in that: A valve block is provided between two variable displacement pump units in a hydraulic pump device arranged in a row along a first direction, and comprises: a block body formed with flow paths for regulator control respectively connected to the regulators provided in the pump section; and a check valve provided on the block body in the form of being respectively interposed in the control flow path of the regulator; The check valve is inserted into the block body from one side in a second direction perpendicular to the first direction and is provided.

2. The valve block according to claim 1, characterized in that: A plurality of the check valves are provided; Each of the regulator control flow paths includes: a first flow path portion for guiding the discharge pressure of the pump portion; a second flow path portion for guiding a predetermined input pressure; and a third flow path portion connected to the first flow path portion, the second flow path portion and the regulator; The plurality of check valves are respectively disposed on the first flow path portion and the second flow path portion of each of the regulator control flow paths, and allow flow to the third flow path portion.

3. The valve block according to claim 1, characterized in that: A plurality of the check valves are provided; The block body includes a valve mounting portion, which is formed on both sides in the first direction in a form adjacent to the regulator arranged on one side of the pump portion in the second direction; The valve mounting portion is formed on the block body to protrude toward one side of the second direction; The plurality of check valves are inserted into the valve mounting portions from one side in the second direction.

4. A hydraulic pump device, characterized in that: have: The valve block according to claim 1; two variable capacity type pump units arranged side by side in a first direction with the valve block interposed therebetween; and The regulators are respectively provided in the first direction of the pump units and adjust the discharge capacities of the pump units.

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