Control valves, hydraulic circuits, hydraulic equipment and construction machinery

Abstract

The present invention provides a control valve, a hydraulic circuit, a hydraulic device, and a construction machine. The control valve (30) comprises: a valve body (40) provided with a valve column hole (41) and at least a first port, a second port, and a universal port communicating with the valve column hole (41); a first valve column (60) capable of moving in the valve column hole (41) of the valve body (40) and capable of connecting the first port and the universal port via the valve column hole (41); and a second valve column (70) capable of moving in the valve column hole (41) of the valve body and capable of connecting the second port and the universal port.

Description

Technical Field

[0001] The invention relates to a control valve, a hydraulic circuit, hydraulic equipment and a construction machine. Background Art

[0002] For example, as disclosed in Japanese Patent Application JP1996-170353A, a control valve is known that includes a valve body and a valve spool disposed within a valve spool bore in the valve body. The valve spool is provided with a notch, and the notch-forming portion of the valve spool has a reduced diameter. The notch-forming portion of the valve spool faces two ports connected to the valve spool bore, thereby connecting the two ports via the valve spool bore. Meanwhile, a shoulder portion of the valve spool, where the notch is not formed, is located between the two ports of the valve spool bore, thereby blocking the connection between the two ports. Summary of the Invention

[0003] In conventional control valves, when two ports are connected, the notch formed in the valve spool is located in the spool hole connecting the two ports. Consequently, when fluid flows between the two ports, pressure loss occurs due to the presence of this notch. The present invention was developed with this in mind, with the goal of reducing pressure loss in control valves.

[0004] The first control valve of the present invention comprises:

[0005] a valve body provided with a valve stem hole; and

[0006] A first spool and a second spool are movable in the spool hole of the valve body.

[0007] The second control valve of the present invention comprises:

[0008] a valve body provided with a spool hole and at least two ports communicating with the spool hole; and

[0009] The first spool and the second spool are movable in the spool hole of the valve body and are separated from each other when the two ports are connected via at least the spool hole.

[0010] The third control valve of the present invention comprises:

[0011] a valve body provided with a spool hole and at least two ports communicating with the spool hole; and

[0012] A first spool and a second spool are movable in the spool hole of the valve body and connect the two ports via the spool hole in a state where they are separated from each other.

[0013] The fourth control valve of the present invention comprises:

[0014] a valve body provided with a spool hole and at least a first port, a second port, and a common port communicating with the spool hole;

[0015] a first spool movable in the spool hole of the valve body and capable of connecting the first port and the common port via the spool hole; and

[0016] A second spool is movable in the spool hole of the valve body and is capable of connecting the second port and the common port.

[0017] The fifth control valve of the present invention comprises:

[0018] A valve body provided with: a first valve spool hole and a first port communicating with the first valve spool hole; a second valve spool hole and a second port communicating with the second valve spool hole; and a common port communicating with the first valve spool hole and the second valve spool hole;

[0019] a first spool movable in the first spool hole of the valve body and capable of connecting the first port and the common port via the first spool hole; and

[0020] A second spool is movable in the second spool hole of the valve body and is capable of connecting the second port and the common port.

[0021] In the first to fifth control valves of the present invention, the first spool and the second spool may move synchronously.

[0022] In the first to fifth control valves of the present invention, the first spool and the second spool may move asynchronously.

[0023] In the first to fifth control valves of the present invention, when the two ports are connected, a distance between the first spool and the second spool may be longer than when the connection between the two ports is blocked.

[0024] The first to fifth control valves of the present invention may include a first back pressure chamber communicating with the spool hole via a through hole provided in the first spool, and a second back pressure chamber communicating with the spool hole via a through hole provided in the second spool.

[0025] The first to third control valves of the present invention may include a first movement control unit that controls movement of the first spool and a second movement control unit that controls movement of the second spool.

[0026] The first to third control valves of the present invention may include a first movement control unit that controls the supply of pilot pressure oil for driving the first spool and a second movement control unit that controls the supply of pilot pressure oil for driving the second spool.

[0027] In the first to third control valves of the present invention, when the first spool moves to one side, the second spool also moves to one side, and when the first spool moves to the other side, the second spool remains stationary.

[0028] The first to third control valves of the present invention may include a movement control for controlling the supply of pilot pressure oil for driving the first spool and the second spool.

[0029] The hydraulic circuit of the present invention includes any one of the first to third control valves of the present invention described above.

[0030] The hydraulic equipment of the present invention comprises:

[0031] Any one of the hydraulic circuits of the present invention described above; and

[0032] An actuator is controlled by the hydraulic circuit.

[0033] A construction machine according to the present invention includes any one of the above-described hydraulic circuits according to the present invention.

[0034] According to the present invention, the pressure loss of the control valve can be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a diagram for explaining one embodiment and is a diagram showing a specific example of a control valve incorporated in a construction machine, hydraulic equipment, and a hydraulic circuit.

[0036] Figure 2 It roughly indicates Figure 1 1 is a sectional view of the structure of the control valve, and is a diagram for explaining the operation of the control valve.

[0037] Figure 3 is with Figure 2 The corresponding cross-sectional views are used to explain the operation of the control valve.

[0038] Figure 4 is with Figure 2 The corresponding cross-sectional views are used to explain the operation of the control valve.

[0039] Figure 5 is with Figure 1 The corresponding cross-sectional view is a diagram for explaining a modified example of the control valve.

[0040] Figure 6 It roughly indicates Figure 5 The cross-sectional view of the structure of the control valve is used to illustrate Figure 5 Diagram of the action of the control valve.

[0041] Figure 7 is with Figure 2 This is a corresponding cross-sectional view and is a diagram for explaining another modified example of the control valve.

[0042] Figure 8 is with Figure 2 This is a corresponding cross-sectional view and is a diagram for explaining still another modified example of the control valve. DETAILED DESCRIPTION

[0043] Hereinafter, one embodiment of the present invention will be described with reference to the specific examples shown in the accompanying drawings. In addition, for easy understanding, the elements shown in the drawings may include elements whose sizes and scales are different from the actual sizes and scales.

[0044] The control valve 30 described below is a device that switches the supply of pressurized liquid, particularly pressure oil, and stops the supply. The control valve 30 is installed in a hydraulic circuit including a liquid supply path, for example, a hydraulic circuit 20 including a pressure oil supply path as described below. As an example, the hydraulic circuit and the hydraulic circuit 20 are applicable to a machine used for performing construction work, that is, a construction machine 10. Examples of the construction machine 10 include excavators, cranes, forklifts, etc. The hydraulic circuit 20 applied to the construction machine 10 constitutes a hydraulic device 15 together with an actuator 18 connected to mechanical equipment 13 such as an excavator, crane, forklift, hammer, and travel parts. The hydraulic circuit 20 supplies pressure oil to the actuator 18 and discharges pressure oil from the actuator 18, thereby controlling the operation of the actuator 18. The operation of the actuator 18 drives the mechanical equipment 13.

[0045] The control valve 30 is described in further detail below. Figure 1 As shown, the control valve 30 includes a valve body 40, and a first spool 60 and a second spool 70 that are movable within a spool bore 41 of the valve body 40. The spool bore 41 is provided in the valve body 40. The spool bore 41 is an elongated hole, forming, for example, a cylindrical space. The first spool 60 and the second spool 70 are movable within the spool bore 41 along the central axis CA of the spool bore 41.

[0046] Furthermore, in the control valve 30 of this embodiment, the valve body 40 is provided with a first port 47B, a second port 48B, and a common port 46B that communicate with the spool bore 41. As the first spool 60 moves within the spool bore 41, the connection between the first port 47B and the common port 46B via the spool bore 41 can be switched between being connected and blocked. Furthermore, as the second spool 70 moves within the spool bore 41, the connection between the second port 48B and the common port 46B via the spool bore 41 can be switched between being connected and blocked.

[0047] Hereinafter, the direction parallel to the central axis CA of the valve stem hole 41, that is, the moving direction of the first valve stem 60 and the second valve stem 70 is referred to as the axial direction AD. Figure 1 The right side of the paper) is set as one side SA and the other side ( Figure 1 In order to make the directional relationship between the drawings clear, Figures 1 to 7 In the drawings, the axial direction AD, one side SA, and the other side SB are commonly used. Furthermore, the "outer side" in the axial direction AD refers to the side farther from the center of the control valve 30 in the axial direction AD. Conversely, the "inner side" in the axial direction AD refers to the side closer to the center of the control valve 30 in the axial direction AD.

[0048] The valve body 40 is formed with a supply passage P and a tank passage T. The supply passage P communicates with a pressure oil pressure-feeding component, such as a pump, in the hydraulic circuit 20. The supply passage P is normally filled with or flows with pressure oil maintained at a high pressure. Meanwhile, the tank passage T is a passage for recovering pressure oil not supplied to the actuator 18 or pressure oil discharged from the actuator 18. The tank passage T is normally connected to a tank (not shown). Pressure oil recovered to the tank via the tank passage T is re-fed into the supply passage P by the pressure oil pressure-feeding component.

[0049] The valve body 40 is provided with a first supply port 47A and a second supply port (the aforementioned first port) 47B, which communicate with the supply passage P via the check valve CV. The first supply port 47A and the second supply port 47B open into the spool bore 41 and communicate with the spool bore 41. Furthermore, the valve body 40 is provided with a first discharge port 48A and a second discharge port (the aforementioned second port) 48B, which communicate with the tank passage T. The first discharge port 48A and the second discharge port 48B open into the spool bore 41 and communicate with the spool bore 41.

[0050] The valve body 40 is also provided with a first actuator port 46A and a second actuator port (common port) 46B, which communicate with the actuator 18. The first actuator port 46A and the second actuator port 46B communicate with different chambers of the hydraulic cylinder that constitutes the actuator 18. In the illustrated example, the second actuator port 46B communicates with the rod chamber 18a on the side through which the rod passes. The first actuator port 46A communicates with the piston chamber 18b on the side through which the rod does not pass. The first actuator port 46A and the second actuator port 46B open into the spool bore 41 and communicate with the spool bore 41.

[0051] In the illustrated example, the first discharge port 48A, the first actuator port 46A, and the first supply port 47A communicate with the spool bore 41 in a region located on one side SA in the axial direction AD. The connection positions (opening positions) of the first discharge port 48A, the first actuator port 46A, and the first supply port 47A with respect to the spool bore 41 are listed in order from the one side SA in the axial direction AD. Similarly, in the illustrated example, the second discharge port 48B, the second actuator port 46B, and the second supply port 47B communicate with the spool bore 41 in a region located on the other side SB in the axial direction AD. The connection positions (opening positions) of the second discharge port 48B, the second actuator port 46B, and the second supply port 47B with respect to the spool bore 41 are listed in order from the other side SB in the axial direction AD.

[0052] In addition, Figure 1 In the illustrated example, the valve body 40 includes a valve block 50; a first side block 51X fixed to the valve block 50 from one side SA in the axial direction AD; and a second side block 51Y fixed to the valve block 50 from the other side SB in the axial direction AD. In the illustrated example, the aforementioned passages P and T and ports 46A, 46B, 47A, 47B, 48A, and 48B are formed in the valve block 50. Meanwhile, the spool hole 41 penetrates the valve block 50 and extends from the valve block 50 to the first side block 51X and the second side block 51Y.

[0053] Next, the first spool 60 and the second spool 70 will be described. The first spool 60 and the second spool 70 are independent components. They are rod-shaped. Each spool 60 and the second spool 70 have a cross-section that corresponds to the cross-sectional shape of the spool bore 41. Furthermore, the first spool 60 or the second spool 70 is positioned within the spool bore 41, restricting the flow of pressurized oil in the axial direction AD within that portion of the spool bore 41.

[0054] The first valve spool 60 has a first top end surface 62 facing inward in the axial direction AD and a first base end surface 63 facing outward (on one side SA) in the axial direction AD. A first through-hole 61 extending between the first top end surface 62 and the first base end surface 63 is provided in the first valve spool 60. The first valve spool 60 has a widened (enlarged diameter) first bulged portion 64 in a region on one side SA in the axial direction AD. The first valve spool 60 bulges in a direction perpendicular to the axial direction AD at the first bulged portion 64. The first bulged portion 64 is formed with a first side shoulder 64X facing the one side SA in the axial direction AD and a first other side shoulder 64Y facing the other side SB in the axial direction AD. Furthermore, the first valve spool 60 has a narrowed (reduced diameter) notch-forming portion 65 in the region between the first top end surface 62 and the first bulged portion 64 in the axial direction AD. Specifically, the first valve spool 60 has a notch 65C formed in the notch-forming portion 65, resulting in a recess in a direction perpendicular to the axial direction AD.

[0055] Similarly, the second valve spool 70 has a second top end surface 72 facing inward in the axial direction AD and a second base end surface 73 facing outward (the other side SB) in the axial direction AD. A second through-hole 71 extending between the second top end surface 72 and the second base end surface 73 is provided in the second valve spool 70. In the illustrated example, the first valve spool 60 is located on one side SA of the second valve spool 70 in the axial direction AD. Furthermore, the second top end surface 72 of the second valve spool 70 faces the first top end surface 62 of the first valve spool 60 in the axial direction AD. Furthermore, the second valve spool 70 has a widened (enlarged) second bulged portion 74 in the region on the other side SB in the axial direction AD. Specifically, the second valve spool 70 bulges out in a direction perpendicular to the axial direction AD at the second bulged portion 74. The second bulged portion 74 is formed with a second first shoulder 74X facing the one side SA in the axial direction AD and a second second second shoulder 74Y facing the other side SB in the axial direction AD.

[0056] The first spool 60 and the second spool 70 move in the axial direction AD within the spool bore 41, thereby connecting the two ports via the spool bore 41 or blocking the connection between the two ports via the spool bore 41. In the illustrated example, the two ports that are connected and blocked are two ports that communicate with the spool bore 41 at adjacent positions in the axial direction AD.

[0057] In the illustrated example, the first spool 60 switches between connecting and blocking the first actuator port 46A and the first supply port 47A, and between blocking and connecting the first actuator port 46A and the first discharge port 48A. As described above, the first spool 60 has a cross-section that corresponds to the cross-sectional shape of the spool bore 41. Therefore, when the first spool 60 is located within the spool bore 41, it restricts the flow of pressurized oil within the spool bore 41 in the axial direction AD. Meanwhile, the first spool 60 has a notch 65C formed in the notch-forming portion 65. Furthermore, the notch-forming portion 65 is arranged to overlap with the connection positions (opening positions) of the two ports relative to the spool bore 41 in the axial direction AD, in other words, to face both of the connection positions (opening positions) of the two ports relative to the spool bore 41 in a direction perpendicular to the axial direction AD. This allows two adjacent ports in the axial direction AD to be connected to each other via the notch 65C. That is, by moving the first spool 60 provided with the notch 65C in the axial direction AD, the connection and blockage between the first actuator port 46A and the first supply port 47A can be switched, and the blockage and connection between the first actuator port 46A and the first discharge port 48A can be switched.

[0058] In this embodiment, the first top end surface 62 of the first valve spool 60 and the second valve spool 70 can be separated from each other in the axial direction AD. At this time, a space S is formed between the first top end surface 62 of the first valve spool 60 and the second top end surface 72 of the second valve spool 70. This space S functions in the same way as the notch 65C of the first valve spool 60 to switch between connection and disconnection of the two ports. Specifically, the space S is formed so as to overlap with the connection positions (opening positions) of the two ports relative to the valve spool hole 41 in the axial direction AD, in other words, so as to face both the connection positions (opening positions) of the two ports relative to the valve spool hole 41 in a direction perpendicular to the axial direction AD, thereby connecting two ports adjacent to each other in the axial direction AD via the space S. In the example shown in the figure, the first valve column 60 and the second valve column 70 can switch the connection and blockage between the second actuator port (universal port) 46B and the second supply port (first port) 47B by adjusting the position of the space S, and can switch the blockage and connection between the second actuator port (universal port) 46B and the second discharge port (second port) 48B.

[0059] Next, the structure for moving the first valve stem 60 and the second valve stem 70 in the axial direction AD is described. First, a first side chamber 43AX and a first other side chamber 43AY are provided between the first valve stem 60 and the valve body 40. The first side chamber 43AX is formed on one side SA of the first bulge 64 of the first valve stem 60 in the axial direction AD. The first side shoulder 64X of the first bulge 64 constitutes a portion of the wall portion that defines and forms the first side chamber 43AX. The first side shoulder 64X, which faces the one side SA in the axial direction AD, is pushed toward the other side SB in the axial direction AD by the pressure within the first side chamber 43AX. The valve body 40 is provided with a first side passage 44AX that communicates with the first side chamber 43AX. Similarly, the first other side chamber 43AY is formed on the other side SB of the first bulge 64 of the first valve stem 60 in the axial direction AD. The first other-side shoulder 64Y of the first bulged portion 64 forms part of the wall defining the first other-side chamber 43AY. The first other-side shoulder 64Y, which faces the other side SB in the axial direction AD, is pressed toward the one side SA in the axial direction AD by the pressure within the first other-side chamber 43AY. A first other-side passage 44AY is provided in the valve body 40, communicating with the first other-side chamber 43AY.

[0060] In the example shown in the figure, the first one side chamber 43AX and the first other side chamber 43AY are formed between the first spool 60 and the first side block 51X. In addition, the first one side passage 44AX and the first other side passage 44AY are formed in the first side block 51X.

[0061] The control valve 30 also includes a movement control unit 80 that controls the movement of the first spool 60 in the axial direction AD. In the illustrated example, the movement control unit 80 switches between supplying and stopping the pilot pressure oil to the first one-side passage 44AX and the first other-side passage 44AY. Typically, such a movement control unit 80 can be a switching valve.

[0062] As described above, the first spool 60 is formed with the first through-hole 61. Furthermore, the valve body 40 is provided with a first back-pressure chamber 42A, which communicates with the portion of the first top end surface 62 of the spool bore 41 via the first through-hole 61 of the first spool 60. The first base end surface 63 of the first spool 60 constitutes a portion of the wall defining the first back-pressure chamber 42A. The first base end surface 63, which faces one side SA in the axial direction AD, is pressed toward the other side SB in the axial direction AD by the pressure within the first back-pressure chamber 42A. Meanwhile, the first top end surface 62, which faces the other side SB in the axial direction AD, is pressed toward the one side SA in the axial direction AD by the pressure within the spool bore 41 (space S). The flow of pressurized oil through the first through-hole 61 maintains the pressure within the first back-pressure chamber 42A at the same level as the pressure within the spool bore 41 (space S). Furthermore, by making the areas of the first top end surface 62 and the first base end surface 63 equal, the force applied to the first top end surface 62 and the force applied to the first base end surface 63 can be made equal. Therefore, even when, for example, high-pressure oil flows into the space S, the first spool 60 can be smoothly moved with a small force.

[0063] The valve body 40 also includes a first positioning member 56A for positioning the first valve spool 60 in a neutral state, i.e., when no driving force for movement is applied. In the illustrated example, the first positioning member 56A includes a first side pressing member 57AX disposed within the first side chamber 43AX and a first other side pressing member 57AY disposed within the first other side chamber 43AY. The first side pressing member 57AX is disposed between the valve body 40 and the first side shoulder 64X of the first valve spool 60. The first side pressing member 57AX presses the first valve spool 60 toward the other side SB in the axial direction AD via the first side shoulder 64X. The first other side pressing member 57AY is disposed between the valve body 40 and the first other side shoulder 64Y of the first valve spool 60. The first other side pressing member 57AY presses the first valve spool 60 toward the one side SA in the axial direction AD via the first other side shoulder 64Y. The first valve spool 60, to which no driving force is applied, can be positioned at a position in the axial direction AD at which the force of the first one-side pressing member 57AX pressing the first valve spool 60 is balanced with the force of the first other-side pressing member 57AY pressing the first valve spool 60. The first one-side pressing member 57AX and the first other-side pressing member 57AY can be elastic bodies, typically compression springs, housed in a compressed state in the first one-side chamber 43AX or the first other-side chamber 43AY.

[0064] On the other hand, a second side chamber 43BX and a second other side chamber 43BY are provided between the second valve spool 70 and the valve body 40. The second side chamber 43BX is formed on one side SA of the second bulged portion 74 of the second valve spool 70 in the axial direction AD. The second side shoulder 74X of the second bulged portion 74 constitutes a portion of the wall defining the second side chamber 43BX. The second side shoulder 74X, which faces the one side SA in the axial direction AD, is pushed toward the other side SB in the axial direction AD by the pressure within the second side chamber 43BX. The valve body 40 is provided with a second side passage 44BX that communicates with the second side chamber 43BX. Similarly, the second other side chamber 43BY is formed on the other side SB of the second bulged portion 74 of the second valve spool 70 in the axial direction AD. The second other side shoulder 74Y of the second bulged portion 74 constitutes a portion of the wall defining the second other side chamber 43BY. The second other side shoulder portion 74Y facing the other side SB in the axial direction AD is pressed toward the one side SA in the axial direction AD by the pressure in the second other side chamber 43BY. The valve body 40 is provided with a second other side passage 44BY communicating with the second other side chamber 43BY.

[0065] In the example shown in the figure, the second one side chamber 43BX and the second other side chamber 43BY are formed between the second spool 70 and the second side block 51Y. In addition, the second one side passage 44BX and the second other side passage 44BY are formed in the second side block 51Y.

[0066] The aforementioned movement control unit 80 also controls the movement of the second valve stem 70 in the axial direction AD. The movement control unit 80 switches between supplying and stopping the pilot pressure oil to the second side chamber 43BX. The second side passage 44BX, which communicates with the second side chamber 43BX, communicates with the first side passage 44AX, which communicates with the first side chamber 43AX. Furthermore, when pilot pressure oil is supplied to the first side chamber 43AX under the control of the movement control unit 80, pilot pressure oil is also supplied to the second side chamber 43BX. Furthermore, when the supply of pilot pressure oil to the first side chamber 43AX is stopped under the control of the movement control unit 80, the supply of pilot pressure oil to the second side chamber 43BX is also stopped.

[0067] Similar to the first spool 60, the second spool 70 is formed with a second through-hole 71. Furthermore, the valve body 40 is provided with a second back-pressure chamber 42B, which communicates with the portion of the second top end surface 72 of the spool bore 41 via the second through-hole 71 of the second spool 70. The second base end surface 73 of the second spool 70 forms part of the wall defining the second back-pressure chamber 42B. The second base end surface 73, facing the other side SB in the axial direction AD, is pressed toward the one side SA in the axial direction AD by the pressure within the second back-pressure chamber 42B. Similar to the first spool 60, by making the areas of the second top end surface 72 and the second base end surface 73 equal, the forces applied to the second top end surface 72 and the second base end surface 73 can be made equal. Consequently, even when, for example, high-pressure oil flows into the space S, the second spool 70 can be moved smoothly with minimal force.

[0068] In addition, the valve body 40 has a second positioning component 56B for positioning the second valve spool 70 in a state where no driving force for movement is applied, i.e., in a neutral state. In the illustrated example, the second positioning component 56B has a second other-side pressing member 57BY disposed in the second other-side chamber 43BY. The second other-side pressing member 57BY is disposed between the valve body 40 and the second other-side shoulder 74Y of the second valve spool 70. The second other-side pressing member 57BY presses the second valve spool 70 toward one side SA in the axial direction AD via the second other-side shoulder 74Y. In the illustrated example, the second one-side pressing member is not provided in the second one-side chamber 43BX. The second other-side pressing member 57BY presses the second valve spool 70, thereby enabling the first valve spool 60, to which no driving force is applied, to be positioned toward one side SA in the axial direction AD. That is, in the example shown in the figure, even if the pilot pressure oil is not supplied to the second other-side passage 44BY, the second spool 70 can be moved to the one side SA in the axial direction AD by the second positioning member 56B. The second other-side pressing member 57BY can be an elastic body, typically a compression spring, housed in a compressed state in the second other-side chamber 43BY.

[0069] Next, the main reference Figures 2 to 4 The operation of the control valve 30 composed of the above structure will be described. Figures 2 to 4 It roughly indicates Figure 1 A cross-sectional view of the structural elements of the control valve 30 is shown.

[0070] exist Figure 2 In the state shown, the movement control unit 80 does not supply pilot pressure oil to any of the passages 44AX, 44AY, 44BX, and 44BY. In other words, the movement control unit 80 stops supplying pilot pressure oil to each chamber 43AX, 43AY, 43BX, and 43BY. Figure 2The control valve 30 is shown in a so-called neutral position. At this time, the first spool 60 is positioned at a predetermined position by the first positioning member 56A. Similarly, the second spool 70 is positioned at a predetermined position by the second positioning member 56B.

[0071] exist Figure 2 In this state, the notch-forming portion 65 of the first valve spool 60, which forms the notch 65C, overlaps only with the first actuator port 46A in the axial direction AD and is offset from the other ports in the axial direction AD. In other words, the notch-forming portion 65 faces only the first actuator port 46A in a direction perpendicular to the axial direction AD and does not face the other ports. Therefore, the first actuator port 46A is not connected to either the first supply port 47A or the first discharge port 48A.

[0072] Likewise, in Figure 2 In this state, the space S between the first valve spool 60 and the second valve spool 70 overlaps only with the second actuator port (common port) 46B in the axial direction AD and is offset from the other ports in the axial direction AD. In other words, the space S faces only the second actuator port 46B in a direction perpendicular to the axial direction AD and does not face the other ports. Therefore, the second actuator port (common port) 46B is not connected to either the second supply port (first port) 47B or the second discharge port (second port) 48B. Stated another way, the portion of the first valve spool 60 located in the spool bore 41 between the second actuator port (common port) 46B and the second supply port (first port) 47B blocks the second actuator port (common port) 46B and the second supply port (first port) 47B. The second spool 70 is located in the spool hole 41 between the second actuator port (common port) 46B and the second discharge port (second port) 48B, blocking the second actuator port (common port) 46B and the second discharge port (second port) 48B.

[0073] Then, in Figure 3 In the state shown, the movement control unit 80 supplies pilot pressure oil to the first side passage 44AX and the second side passage 44BX. That is, the pilot pressure oil is supplied to the first side chamber 43AX and the second side chamber 43BX. As a result, the pilot pressure oil is discharged from the first other side chamber 43AY and the second other side chamber 43BY. Figure 3 As shown, the first valve rod 60 and the second valve rod 70 are Figure 2 The neutral position shown is shifted to the other side SB in the axial direction AD.

[0074] exist Figure 3In this state, the notch-forming portion 65 of the first valve spool 60, which forms the notch 65C, overlaps with both the first actuator port 46A and the first supply port 47A in the axial direction AD and is offset from the other ports in the axial direction AD. In other words, the notch-forming portion 65 faces both the first actuator port 46A and the first supply port 47A in a direction perpendicular to the axial direction AD and does not face the other ports. As a result, the first actuator port 46A communicates with the first supply port 47A via the portion of the spool bore 41 where the notch 65C is located. Pressurized oil supplied from the supply passage P then flows into the piston chamber 18b of the actuator 18 through the first supply port 47A and the first actuator port 46A.

[0075] In addition, Figure 3 In this state, the space S between the first spool 60 and the second spool 70 overlaps with both the second actuator port 46B and the second discharge port 48B in the axial direction AD and is offset from the other ports in the axial direction AD. In other words, the space S faces both the second actuator port 46B and the second discharge port 48B in a direction perpendicular to the axial direction AD and does not face the other ports. As a result, the second actuator port 46B communicates with the second discharge port 48B via the portion of the spool bore 41 where the space S is located. Furthermore, the pressurized oil discharged from the rod chamber 18a of the actuator 18 passes through the second actuator port 46B and the second discharge port 48B and is recovered in a tank (not shown).

[0076] Using other expressions, Figure 3 In this state, the first spool 60 is located in the portion of the spool bore 41 between the second actuator port (common port) 46B and the second supply port (first port) 47B, blocking the second actuator port (common port) 46B and the second supply port (first port) 47B. Meanwhile, the second spool 70 is located closer to the second discharge port (second port) 48B than the portion of the spool bore 41 between the second actuator port (common port) 46B and the second discharge port (second port) 48B, leaving the second discharge port (second port) 48B at least partially open in the spool bore 41. Thus, the second spool 70 connects the second actuator port (common port) 46B and the second discharge port (second port) 48B.

[0077] In this embodiment, the first valve rod 60 and the second valve rod 70 are independent components. Figure 3The narrow (thin diameter) connecting portion 90, indicated by the two-dot chain line, is not present between the first spool 60 and the second spool 70. Consequently, the flow path of the pressurized oil from the second actuator port 46B to the second discharge port 48B within the spool bore 41 can be widened. In other words, the cross-sectional area of ​​the flow path for the pressurized oil from the second actuator port 46B to the second discharge port 48B can be increased. Furthermore, the frictional resistance of the pressurized oil from the second actuator port 46B to the second discharge port 48B can be reduced. Consequently, pressure loss within the control valve 30 can be significantly reduced compared to a case where the connecting portion 90 is provided.

[0078] Then, in Figure 4 In the state shown, the movement control unit 80 supplies the pilot pressure oil to the first other side chamber 43AY. That is, the pilot pressure oil is supplied to the first other side chamber 43AY. As a result, the pilot pressure oil is discharged from the first side chamber 43AX. Figure 4 As shown, the first valve column 60 is Figure 2 The neutral position shown is shifted to one side SA in the axial direction AD.

[0079] exist Figure 4 In this state, the notch-forming portion 65 of the first valve spool 60, where the notch 65C is formed, overlaps both the first actuator port 46A and the first discharge port 48A in the axial direction AD and is offset relative to the other ports in the axial direction AD. In other words, the notch-forming portion 65 faces both the first actuator port 46A and the first discharge port 48A in a direction perpendicular to the axial direction AD and does not face the other ports. As a result, the first actuator port 46A communicates with the first discharge port 48A via the portion of the spool bore 41 where the notch 65C is located. Furthermore, the pressurized oil discharged from the piston chamber 18b of the actuator 18 passes through the first actuator port 46A and the first discharge port 48A and is recovered in a tank (not shown).

[0080] exist Figure 4 In this state, the space S between the first spool 60 and the second spool 70 overlaps with both the second actuator port 46B and the second supply port 47B in the axial direction AD, and is offset from the other ports in the axial direction AD. In other words, the space S faces both the second actuator port 46B and the second supply port 47B in a direction perpendicular to the axial direction AD, and does not face the other ports. As a result, the second actuator port 46B communicates with the second supply port 47B via the portion of the spool bore 41 where the space S is located. Furthermore, the pressurized oil supplied from the supply passage P flows into the rod chamber 18a of the actuator 18 through the second supply port 47B and the second actuator port 46B.

[0081] Using other expressions, Figure 4In this state, the first spool 60 is located in the spool bore 41 at a position closer to the second supply port (first port) 47 than the portion between the second actuator port (common port) 46B and the second supply port (first port) 47B, so that the second supply port (first port) 47B is at least partially open in the spool bore 41. Thus, the first spool 60 connects the second actuator port (common port) 46B and the second supply port (first port) 47B.

[0082] In the example shown in the figure, the movement control unit 80 is Figure 4 In the state of , the pilot pressure oil is not supplied to the first side chamber 43AX and the second other side chamber 43BY. At this time, the second valve rod 70 is positioned by the second other side pressing member 57BY of the second positioning component 56B. Figure 4 In the state shown, the first valve column 60 is Figure 2 From the state shown, the second valve stem 70 moves to one side SA along the axial direction AD, but the second valve stem 70 is located at the same position as the second valve stem 70 in the axial direction AD. Figure 2 That is, the first spool 60 and the second spool 70 move asynchronously.

[0083] Furthermore, two ports (specifically, the second actuator port 46B and the second supply port 47B) are connected. Figure 4 The separation distance LD of the first valve stem 60 and the second valve stem 70 along the axial direction AD is greater than the distance LD that blocks the connection between the two ports. Figure 2 In this state, the separation distance LD between the first spool 60 and the second spool 70 along the axial direction AD is long. As a result, at least one of the two connected ports can be more widely exposed to the spool bore 41. In the illustrated example, the connection portion of the second actuator port 46B to the spool bore 41 is not blocked by the second spool 70 and is widely open to the spool bore 41. In other words, in addition to eliminating the aforementioned connecting portion 90, the separation distance LD between the first spool 60 and the second spool 70 is further increased, thereby expanding the space S, thereby further significantly reducing pressure loss within the control valve 30.

[0084] In one embodiment described above, the control valve 30 includes a valve body 40 provided with a valve column hole 41, and a first valve column 60 and a second valve column 70 provided in a manner movable in the valve column hole 41 of the valve body 40. According to such a control valve 30, when two ports communicating with the valve column hole 41 are connected via the valve column hole 41, the first valve column 60 and the second valve column 70 can be separated from each other in the valve column hole 41. Therefore, the first valve column 60 and the second valve column 70 can be moved out of the area between the two ports to be connected of the valve column hole relative to the opening position (connection position) of the valve column hole 41. Thus, the narrow width (thin diameter) portion 90 (refer to Figure 3 ) remains in the region connecting the two ports of the spool hole 41, resulting in a reduction in cross-sectional area and friction at the surface of the portion 90. As a result, the pressure loss in the control valve 30 can be effectively reduced.

[0085] In the above-described embodiment, the control valve 30 includes a valve body having a spool bore 41 and at least a first port (second supply port) 47B, a second port (second discharge port) 48B, and a common port (second actuator port) 46B communicating with the spool bore 41; a first spool 60 that is movable within the spool bore 41 of the valve body 40 and connects the first port (second supply port) 47B and the common port (second actuator port) 46B via the spool bore 41; and a second spool 70 that is movable within the spool bore 41 of the valve body 40 and connects the second port (second discharge port) 48B and the common port (second actuator port) 46B. With this control valve 30, when the two ports communicating with the spool bore 41 are connected via the spool bore 41, the first spool 60 and the second spool 70 can be separated from each other within the spool bore 41. Therefore, the first valve spool 60 and the second valve spool 70 can be moved out of the area between the opening positions (connection positions) of the two ports to be connected to the valve spool hole 41 relative to the valve spool hole 41. Figure 3 ) remains in the region connecting the two ports of the spool hole 41, resulting in a reduction in cross-sectional area and friction at the surface of the portion 90. As a result, the pressure loss in the control valve 30 can be effectively reduced.

[0086] In a specific example of the above-mentioned embodiment, the first spool 60 and the second spool 70 move asynchronously. That is, the first spool 60 and the second spool 70 can be moved independently. According to such an example, pressure loss can be reduced more effectively.

[0087] In a specific example of the aforementioned embodiment, the separation distance LD between the first spool 60 and the second spool 70 when two ports (e.g., the second actuator port 46B and the second supply port 47B) are connected is longer than the separation distance LD when the two ports are disconnected. This example effectively reduces pressure loss when connecting the two ports. Furthermore, when the two ports are disconnected, unintended leakage of pressurized oil can be effectively prevented.

[0088] In a specific example of the aforementioned embodiment, the control valve 30 includes a first backpressure chamber 42A communicating with the spool bore 41 via a first through-hole 61 provided in the first spool 60; and a second backpressure chamber 42B communicating with the spool bore 41 via a second through-hole 71 provided in the second spool 70. This example significantly reduces the driving force required to drive the first spool 60. Furthermore, the driving force required to drive the second spool 70 can be significantly reduced. This simplifies the structure of the control valve 30, resulting in a smaller and lighter control valve 30.

[0089] In a specific example of the above embodiment, when the first valve rod 60 moves to one side (for example, from Figure 2 The state shown is moved to the other side SB along the axial direction AD. Figure 3 When the second valve rod 70 is in the state shown in FIG, the second valve rod 70 also moves to one side. On the other hand, when the first valve rod 60 moves to the other side (for example, from Figure 2 The state shown is moved to one side SA along the axial direction AD. Figure 4 (In the state shown in FIG. 1 ), the second spool 70 is stationary. According to this example, the structure and control for driving the second spool 70 can be simplified. In addition, by moving only the first spool 60 while the second spool 70 is stationary, a larger flow path for the pressurized oil formed by the space S can be ensured, and pressure loss can be more effectively reduced.

[0090] In a specific example of the aforementioned embodiment, the control valve 30 includes a movement control unit (pressure oil supply control unit, pressure oil supply control valve) 80 that controls the supply of pilot pressure oil for driving the first spool 60 and the second spool 70. A single movement control unit 80 controls both the movement of the first spool 60 and the movement of the second spool 70. This example allows the positions of the first and second spools to be controlled by a single drive unit (pressure oil supply control unit, pressure oil supply control valve), thereby reducing the size and weight of the directional control valve.

[0091] While one embodiment has been described with reference to specific examples, the above specific examples are not intended to limit the embodiment. The above embodiment can be implemented with various other specific examples, and various omissions, substitutions, changes, and additions can be made without departing from the scope of the present invention.

[0092] Below, with reference to the attached Figure 1 In the following description and the drawings used in the following description, parts that can be configured similarly to the above-mentioned specific example are denoted by the same reference numerals as those used for corresponding parts in the above-mentioned specific example, and duplicate descriptions are omitted.

[0093] First, the first spool 60 and the second spool 70 may also move synchronously when moving to either side in the axial direction AD. According to such an example, the pressure loss can be effectively reduced with simple control and structure.

[0094] Specifically, the control valve 30 can be constructed as follows. First, the second positioning component 56B, in addition to the second other-side pressing member 57BY, further includes a second one-side pressing member within the second one-side chamber 43BX. This second one-side pressing member is positioned between the valve body 40 and the second one-side shoulder 74X of the second valve spool 70, and presses the second valve spool 70 toward the other side SB in the axial direction AD via the second one-side shoulder 74X. The second valve spool 70, in its neutral position, is positioned so that the force from the second other-side pressing member 57BY and the force from the second one-side pressing member are balanced, and is thus able to move in both directions in the axial direction AD from its neutral position.

[0095] Furthermore, in addition to switching the supply and stop of pilot pressure oil to the second one-side chamber 43BX, the movement control unit 80 also switches the supply and stop of pilot pressure oil to the second other-side chamber 43BY. Specifically, the second other-side passage 44BY communicating with the second other-side chamber 43BY may be connected to the first other-side passage 44AY communicating with the first other-side chamber 43AY. In this example, when pilot pressure oil is supplied to the first other-side chamber 43AY under the control of the movement control unit 80, pilot pressure oil is also supplied to the second other-side chamber 43BY. Furthermore, when the supply of pilot pressure oil to the first other-side chamber 43AY is stopped under the control of the movement control unit 80, the supply of pilot pressure oil to the second other-side chamber 43BY is also stopped.

[0096] According to such an example, it is possible to synchronously move the first spool 60 and the second spool 70. According to this example, it is possible to effectively reduce pressure loss with simple control and structure.

[0097] In the above example, a single movement control unit 80 controls both the movement of the first spool 60 and the movement of the second spool 70. However, the present invention is not limited to this example. The control valve 30 may also independently include a first movement control unit 80A for controlling the movement of the first spool 60 and a second movement control unit 80B for controlling the movement of the second spool 70. This example allows for independent control of the movement of the first spool 60 and the second spool 70. Consequently, pressure loss can be more effectively reduced.

[0098] As an example of such a variation, Figure 5The control valve 30 shown in FIG. 1 independently includes a first movement control unit (first pressure oil supply control unit) 80A, which controls the supply of pilot pressure oil for driving the first spool 60, and a second movement control unit (second pressure oil supply control unit) 80B, which controls the supply of pilot pressure oil for driving the second spool 70. This example allows the movement of the first spool 60 and the second spool 70 to be independently controlled using a simple structure and simple control.

[0099] exist Figure 5 In the example shown, the first movement control unit 80A and the second movement control unit 80B can be constituted by, for example, switching valves for switching flow paths, similarly to the above-mentioned movement control unit 80. Figure 6 The status shown is from Figure 2 From the neutral state shown, the first valve spool 60 and the second valve spool 70 are moved together along the axial direction AD toward the other side SB. However, the amount of movement of the second valve spool 70 toward one side SA along the axial direction AD is longer than the amount of movement of the first valve spool 60 toward one side SA along the axial direction AD. As a result, the valve connecting the two ports (the second actuator port 46B and the second discharge port 48B) is Figure 6 The separation distance LD of the first valve stem 60 and the second valve stem 70 in the axial direction AD is greater than the distance LD that blocks the connection between the two ports. Figure 2 The separation distance LD between the first valve stem 60 and the second valve stem 70 is long in the state. According to such an example, the pressure loss can be reduced more effectively. In addition, Figure 6 The position of the first valve column 60 in Figure 3 The position of the first valve column 60 is the same as that of the first valve column 60. Figure 6 The position of the second valve column 70 indicated by the double-dashed line is Figure 3 The position of the second valve stem 70 in the same. And, the two ports (the second actuator port 46B and the second discharge port 48B) are connected Figure 3 The separation distance LD between the first valve stem 60 and the second valve stem 70 in the axial direction AD and the distance between the first valve stem 60 and the second valve stem 70 in the axial direction AD are the same as the distance between the first valve stem 60 and the second valve stem 70 in the axial direction AD. Figure 2 In the state of , the first spool 60 and the second spool 70 are separated by the same distance LD.

[0100] On the other hand, Figure 5 In the control valve 30 shown in FIG. 1 , when the first spool 60 is moved toward one side SA along the axial direction AD, the second movement control portion 80B can be operated as follows. Figure 4 As in the example shown, the second spool 70 may be kept stationary and the second spool 70 may be moved to one side SA along the axial direction AD by an amount smaller than the amount of movement of the first spool 60 .

[0101] However, depending on the type of actuator being driven, control methods such as single-acting and hammer-type control are used to control the supply and discharge of pressure oil to and from the actuator. In conventional control methods, the supply and discharge of pressure oil to and from the actuator are both performed simultaneously via two pathways within a single control valve. The proportional valve that drives the valve spool is controlled to balance the amount of pressure oil supplied to and discharged from the actuator. However, in control methods such as single-acting and hammer-type control, while pressure oil is supplied to the actuator by driving the valve spool as is conventional, the discharge path for pressure oil from the actuator remains fully open or open to a certain amount. For example, mechanical equipment such as a hammer discharges pressure oil when the pressure of the supplied pressure oil exceeds a predetermined value. Consequently, the amount of pressure oil supplied to the actuator via the control valve differs significantly from the amount of pressure oil discharged. Such discharge of pressure oil from the control valve can damage the control valve. Therefore, in control methods such as the single-acting type and the hammer type, it is necessary to separately provide a dedicated discharge path that does not pass through the control valve, which complicates the hydraulic circuit and increases the size of the hydraulic equipment.

[0102] On the other hand, this embodiment is also very suitable for such control methods as single-action type, hammer type, etc. For example, Figure 6 As shown, by controlling the position of the first spool 60, the amount of pressurized oil supplied to the actuator 18 can be controlled. Meanwhile, by maintaining the second spool 70 at a predetermined position, for example, by maintaining the second spool 70 in a position that fully opens the second discharge port 48B, a pressure oil discharge path capable of always discharging a predetermined amount of pressurized oil can be ensured within the control valve 30 regardless of the position of the first spool 60. This eliminates the need for providing a separate discharge path, leading to a simplified hydraulic circuit 20 and a smaller and lighter hydraulic device 15.

[0103] Moreover, in the above-mentioned specific example, an example is shown in which the movement control unit 80, 80A, 80B is constructed using a pressure oil supply control unit (for example, a pressure oil supply control valve) that switches the supply and stop of the pilot pressure oil, but this is not limited to this example, and other components, such as motors, may also be used.

[0104] In the above example, both the first valve spool 60 and the second valve spool 70 are arranged in a straight line in the valve spool hole 41. In this example, a portion of the first valve spool 60 and a portion of the second valve spool 70 can be arranged at the same position in the valve spool hole 41. However, the present invention is not limited to the above example. For example, Figure 7 and Figure 8 As shown, the first spool 60 may be movable in the first spool hole 41A, and the second spool 70 may be movable in the second spool hole 41B. Figure 7 and Figure 8 In the illustrated example, the central axis CA1 of the first spool hole 41A and the central axis CA2 of the second spool hole 41B are offset from each other and are not located on the same straight line.

[0105] exist Figure 7 and Figure 8 In the illustrated example, the control valve 30 includes a valve body 40 having a first spool bore 41A and a first port (second supply port 47B) communicating with the first spool bore 41A, a second spool bore 41B and a second port (second discharge port 48B) communicating with the second spool bore 41B, and a common port (second actuator port 46B) communicating with the first spool bore 41A and the second spool bore 41B; a first spool 60 that is movable in the first spool bore 41A of the valve body 40 and connects the first port (second supply port 47B) and the common port (second actuator port 46B) via the first spool bore 41A; and a second spool 70 that is movable in the second spool bore 41B of the valve body 40 and connects the second port (second discharge port 48B) and the common port (second actuator port 46B). This control valve 30 can also produce the same effects as those of the above-described embodiment.

[0106] Furthermore, several modified examples of the above-mentioned embodiment have been described above, but it is apparent that a plurality of modified examples can be appropriately combined and used.

Claims

1. A control valve, wherein: The control valve has: a valve body provided with a spool hole and at least a first port, a second port, and a common port communicating with the spool hole; a first spool movable in the spool hole of the valve body and capable of connecting the first port and the common port via the spool hole; a second spool movable in the spool hole of the valve body and capable of connecting the second port and the common port; a first back pressure chamber communicating with the spool hole via a through hole provided in the first spool; and A second back pressure chamber communicates with the spool hole via a through hole provided in the second spool.

2. A control valve, wherein: The control valve has: A valve body provided with: a first valve spool hole and a first port communicating with the first valve spool hole; a second valve spool hole and a second port communicating with the second valve spool hole; and a common port communicating with the first valve spool hole and the second valve spool hole; a first spool movable in the first spool hole of the valve body and capable of connecting the first port and the common port via the first spool hole; a second spool movable in the second spool hole of the valve body and capable of connecting the second port and the common port; a first back pressure chamber communicating with the first spool hole via a through hole provided in the first spool; and A second back pressure chamber communicates with the second spool hole via a through hole provided in the second spool.

3. The control valve according to claim 1 or 2, wherein: The first spool and the second spool move synchronously.

4. The control valve according to claim 1 or 2, wherein: The first spool and the second spool move asynchronously.

5. The control valve according to claim 1 or 2, wherein: In a state where the first port and the common port are connected, a distance between the first spool and the second spool is longer than in a state where the connection between the first port and the common port is blocked.

6. The control valve according to claim 1 or 2, wherein: This control valve includes a first movement control portion that controls movement of the first spool and a second movement control portion that controls movement of the second spool.

7. The control valve according to claim 1 or 2, wherein: This control valve includes: a first movement control portion that controls the supply of pilot pressure oil for driving the first spool; and a second movement control portion that controls the supply of pilot pressure oil for driving the second spool.

8. The control valve according to claim 1 or 2, wherein: When the first valve column moves to one side, the second valve column also moves to one side. When the first spool moves to the other side, the second spool remains stationary.

9. A hydraulic circuit, wherein: This hydraulic circuit includes the control valve according to claim 1 or 2.

10. A hydraulic device, wherein: The hydraulic equipment has: The hydraulic circuit according to claim 9; and An actuator is controlled by the hydraulic circuit.

11. A construction machine, wherein: This construction machine includes the hydraulic circuit according to claim 9.

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