Hydraulic valve device

Abstract

In order to improve the straightness of a work machine provided with two hydraulic devices for travel, provided is a hydraulic valve device (1) which is interposed between a hydraulic device and a hydraulic pump and which controls the supply of oil from the hydraulic pump to the hydraulic device by operating a spool provided in a valve body (20) provided with: a separate spool (34) for travel; the two hydraulic motors (7) are arranged corresponding to the two hydraulic motors (7) for driving; a cylinder spool (33) provided corresponding to the hydraulic cylinders (11, 12); and two pump oil passages (21A, 21B) that are connected to the hydraulic pump via the pump ports (22A, 22B), and the two travel spool valves (34) are connected to the separate pump oil passages (21A, 21B) at positions at which the distances from the two travel spool valves (34) to the pump ports (22A, 22B) are equal to each other without via the other spool valves (33, 35).

Description

Technical Field

[0001] The present invention relates to a hydraulic valve device, and more particularly to a hydraulic valve device including a travel slide valve provided corresponding to a travel hydraulic device and a work implement slide valve provided corresponding to a work implement hydraulic device. Background Art

[0002] For example, a work machine is equipped with a hydraulic motor as a travel hydraulic device and a hydraulic cylinder as a work implement hydraulic device. These hydraulic devices are operated appropriately to perform the desired work. A hydraulic valve device is provided between each hydraulic device and a hydraulic pump, which serves as the oil supply source. This device controls the supply of oil from the hydraulic pump to the hydraulic device. Specifically, the hydraulic valve device includes a separate spool valve within the valve body, corresponding to each hydraulic device. By operating the spool valve, the supply of oil to the hydraulic device can be controlled (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-113809 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In a typical work machine, crawler tracks and other travel devices are installed on each side of the vehicle body, and two hydraulic motors are provided to drive these travel devices. Therefore, by independently driving the left and right travel devices, the work machine can not only move forward and backward, but also change its direction of travel as needed to travel along a desired trajectory. However, in the aforementioned hydraulic valve device, even when the two travel slide valves are operated to ensure the same oil flow rate to the left and right hydraulic motors, the actual oil pressure and flow rate supplied to the hydraulic motors can differ, potentially causing the work machine to not move straight.

[0008] In view of the above-mentioned actual situation, an object of the present invention is to provide a hydraulic valve device capable of improving the straightness of a working machine provided with two hydraulic devices for traveling when applied to the working machine.

[0009] Means for solving problems

[0010] In order to achieve the above-mentioned purpose, the hydraulic valve device of the present invention is interposed between the hydraulic equipment and the hydraulic pump, and controls the supply of oil from the hydraulic pump to the hydraulic equipment by actuating the sliding valve provided on the valve body. The valve body is characterized in that the valve body has: a separate sliding valve for travel, which is provided corresponding to the two hydraulic equipment for travel; a sliding valve for working device, which is provided corresponding to the hydraulic equipment for working device; and two pump oil circuits, which are connected to the hydraulic pump via a pump port, and the two sliding valves for travel are connected to the separate pump oil circuits at positions equal to each other in distance from the pump ports, respectively, without passing through other sliding valves.

[0011] Effects of the Invention

[0012] According to the present invention, since the two travel spool valves are located at the same distance from the pump port, problems caused by differences in the length of the oil path are eliminated. Furthermore, since there are no other spool valves intervening, problems caused by differences in pressure loss are also eliminated. As a result, by operating the travel spool valves so that the oil supply flow rate to both travel hydraulic systems is the same, the oil supply pressure and flow rate to both travel hydraulic systems can be effectively equalized, thereby improving the straightness of the working machine in which it is used. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a transparent perspective view conceptually showing the interior of a hydraulic valve device as an embodiment of the present invention.

[0014] Figure 2 It is conceptually expressed from another perspective Figure 1 A perspective perspective view of the interior of a hydraulic valve arrangement is shown.

[0015] Figure 3A is Figure 1 The hydraulic valve device shown only shows the structure of the slide valve for the working device. Figure 1 Corresponding perspective stereogram.

[0016] Figure 3B is Figure 1 The hydraulic valve device shown only shows the structure of the slide valve for the working device. Figure 2 Corresponding perspective stereogram.

[0017] Figure 4A is Figure 1 The hydraulic valve device shown only shows the structure of the sliding valve for driving. Figure 1 Corresponding perspective stereogram.

[0018] Figure 4B is Figure 1 The hydraulic valve device shown only shows the structure of the sliding valve for driving. Figure 2Corresponding perspective stereogram.

[0019] Figure 5A is Figure 1 The hydraulic valve device shown only shows the structure of the rotary slide valve. Figure 1 Corresponding perspective stereogram.

[0020] Figure 5B is Figure 1 The hydraulic valve device shown only shows the structure of the rotary slide valve. Figure 2 Corresponding perspective stereogram.

[0021] Figure 6A It means to become Figure 1 The hydraulic valve device shown is an application example of a side view of a working machine.

[0022] Figure 6B It means to become Figure 1 The hydraulic valve device shown is an embodiment of a rear view of a working machine.

[0023] Figure 6C It means to become Figure 1 The hydraulic valve device shown is an upper view of a working machine to which it is applied.

[0024] Figure 7 It schematically indicates the application of Figure 1 A top view of the hydraulic circuit of a working machine showing the hydraulic valve arrangement is shown.

[0025] Figure 8 Observed from the front surface Figure 1 The front view of the hydraulic valve device is shown.

[0026] Figure 9 yes Figure 8 Left side view.

[0027] Figure 10 yes Figure 8 Right view of .

[0028] Figure 11 yes Figure 8 rear view.

[0029] Figure 12 yes Figure 8 Top view of .

[0030] Figure 13 yes Figure 8 Bottom view of .

[0031] Figure 14 yes Figure 8 The X1-X1 line section view in.

[0032] Figure 15 yes Figure 8 The X2-X2 line section view in.

[0033] Figure 16 yes Figure 8 The X3-X3 line section view in.

[0034] Figure 17 yes Figure 8 The X4-X4 line section view in. DETAILED DESCRIPTION

[0035] Hereinafter, preferred embodiments of the hydraulic valve device according to the present invention will be described in detail with reference to the accompanying drawings.

[0036] Figures 1 to 5B The hydraulic valve device as an embodiment of the present invention is conceptually shown. Figure 6A 、 Figure 6B 、 Figure 6C 、 Figure 7As shown, the application target is a work machine equipped with an upper slewing structure 3, a boom 4, and an arm 5 above a lower traveling structure 2. The lower traveling structure 2 has crawler tracks 6 on both sides, and a separate travel hydraulic motor (travel hydraulic device) 7 corresponding to each crawler track 6. The crawler tracks 6 are driven by the travel hydraulic motors 7, enabling travel. The upper slewing structure 3 is supported so that it can rotate relative to the lower traveling structure 2 about a vertical rotation axis. A rotation hydraulic motor 8 is provided between the lower traveling structure 2 and the upper slewing structure 3, enabling rotation of the upper slewing structure 3 relative to the lower traveling structure 2. The travel hydraulic motor 7 and the rotation hydraulic motor 8 each have two supply ports 7a and 8a, enabling forward and reverse rotation by changing the direction of oil supply. A hydraulic pump 9 is mounted on the upper slewing structure 3. The hydraulic pump 9 is driven by an engine 10, and two hydraulic pumps with the same maximum discharge flow rate are provided on the upper slewing structure 3. In the example shown in the figure, an engine 10 is mounted on the left side of the rear portion of the upper revolving body 3, and two hydraulic pumps 9 are mounted on the right side of the rear portion of the upper revolving body 3 adjacent to the engine 10. The boom 4 is rotatably supported on the upper revolving body 3 via a base end portion along a horizontal support shaft. The arm 5 is rotatably supported on the front end portion of the boom 4 via a base end portion along a horizontal support shaft. A boom hydraulic cylinder (hydraulic equipment for a working device) 11 is provided between the upper revolving body 3 and the boom 4, and an arm hydraulic cylinder (hydraulic equipment for a working device) 12 is provided between the boom 4 and the arm 5. The boom hydraulic cylinder 11 and the arm hydraulic cylinder 12 are single-rod double-acting hydraulic cylinders each having a single piston rod. The boom hydraulic cylinder 11 is supported on the upper revolving body 3 via a cylinder body 11a and is supported on the boom 4 via a piston rod 11b. The arm hydraulic cylinder 12 is supported by the boom 4 via a cylinder body 12 a and is supported by the arm 5 via a piston rod 12 b.

[0037] The hydraulic valve device 1 is interposed between the travel hydraulic motor 7, the swing hydraulic motor 8, the boom hydraulic cylinder 11, the arm hydraulic cylinder 12 (hereinafter sometimes collectively referred to as hydraulic equipment) and the hydraulic pump 9, and controls the supply of oil from the hydraulic pump 9 to the hydraulic equipment 7, 8, 11, 12. Figure 1 As shown in FIG. 1 , a valve body 20 is provided. The valve body 20 is configured to Figure 1 In the following description, for convenience, Figure 1 The surface located in front of the right side of the valve body 20 is called the front surface 20a, the surface parallel to the front surface 20a is called the rear surface 20b, and the two surfaces located on both sides are called side surfaces 20c and 20d. Figure 1 In the diagram, the surface located above is referred to as an upper surface 20e, and the surface located below is referred to as a lower surface 20f.

[0038] like Figures 1 to 5B 、 Figures 8 to 17 As shown, two pump oil circuits 21A and 21B are provided inside the valve body 20. The pump oil circuits 21A and 21B extend linearly in the vertical direction of the valve body 20 and are formed to have the same inner diameter. In the illustrated example, the two pump oil circuits 21A and 21B are arranged side by side in bilaterally symmetrical positions, with their portions toward the rear surface 20b being parallel to each other. Although not explicitly shown in the figure, the lower ends of both pump oil circuits 21A and 21B are blocked. Even if the lower ends of the pump oil circuits 21A and 21B are blocked, plugs can be installed after the oil circuits are temporarily formed. The upper ends of the two pump oil circuits 21A and 21B open at the upper surface 20e of the valve body 20. In this embodiment, each pump oil circuit 21A and 21B is connected to a separate hydraulic pump 9 via a pump port 22A or 22B. The pump ports 22A and 22B extend linearly rearward from the pump oil passages 21A and 21B and open at the rear surface 20b of the valve body 20. Although not shown, the distances from the pump ports 22A and 22B to the hydraulic pump 9 are equal.

[0039] In each pump oil passage 21A, 21B, two cylinder spool holes 23 are provided above and below the portion connecting to the pump ports 22A, 22B. Furthermore, in each pump oil passage 21A, 21B, a travel spool hole 24 is provided below the portion connecting to the pump ports 22A, 22B. Furthermore, in the pump oil passage 21A, which is positioned on the left side when viewed from the front surface 20a of the valve body 20, a swing spool hole 25 is provided below the travel spool hole 24. The cylinder spool holes 23, travel spool hole 24, and swing spool hole 25 each extend linearly along the front-to-rear direction of each valve body 20, communicating with the corresponding pump oil passage 21A, 21B by penetrating the corresponding pump oil passage 21A, 21B. Both ends of each spool hole 23, 24, and 25 are blocked.

[0040] Cylinder ports 23a are provided in the cylinder spool holes 23 near the front surface 20a of the valve body 20. Each cylinder port 23a extends from the side portions of the cylinder spool holes 23 facing the side surfaces 20c and 20d of the valve body 20, respectively, toward the side surfaces 20c and 20d, then curves toward the front surface 20a to open at the front surface 20a of the valve body 20. The cylinder port 23a opening in the upper right corner when viewed from the front surface 20a of the valve body 20 is connected to the boom rod oil passage 11Ha, which communicates with the rod chamber 11H of the boom hydraulic cylinder 11. The cylinder port 23a opening in the lower right corner when viewed from the front surface 20a of the valve body 20 is connected to the boom bottom oil passage 11Ba, which communicates with the bottom chamber 11B of the boom hydraulic cylinder 11. Similarly, the cylinder port 23a opening at the upper left when viewed from the front surface 20a of the valve body 20 is connected to the boom bottom oil passage 12Ba communicating with the bottom chamber 12B of the boom hydraulic cylinder 12. The cylinder port 23a opening at the lower left when viewed from the front surface 20a of the valve body 20 is connected to the boom rod oil passage 12Ha communicating with the rod chamber 12H of the boom hydraulic cylinder 12.

[0041] The travel spool hole 24 is provided with travel motor ports 24a1 and 24a2 in portions near the middle portion and near the front surface 20a of the valve body 20, respectively. The travel motor port 24a1 provided in the middle portion of the travel spool hole 24 extends from an upper portion facing the upper surface 20e of the valve body 20 toward the upper surface 20e, then curves toward the front surface 20a, and opens at the front surface 20a of the valve body 20. The travel motor port 24a2 provided in a portion near the front surface 20a of the valve body 20 extends from a lateral portion facing the side surfaces 20c and 20d of the valve body 20 toward the side surfaces 20c and 20d, then curves toward the front surface 20a, and opens at the front surface 20a of the valve body 20. The two travel motor ports 24a1 and 24a2, which open on the left side when viewed from the front surface 20a of the valve body 20, are connected to travel hydraulic motor oil passages 24MA1 and 24MA2, respectively. These travel hydraulic motor oil passages 24MA1 and 24MA2 communicate with the supply port 7a of the travel hydraulic motor 7 disposed on the right side of the lower travel structure 2. The two travel motor ports 24a1 and 24a2, which open on the right side when viewed from the front surface 20a of the valve body 20, are connected to travel hydraulic motor oil passages 24MB1 and 24MB2, respectively. These travel hydraulic motor oil passages 24MB1 and 24MB2 communicate with the supply port 7a of the travel hydraulic motor 7 disposed on the left side of the lower travel structure 2. The oil supply conditions to each travel hydraulic motor 7 are the same on both sides. In other words, the path length of the travel hydraulic motor oil circuit 24MA1+24MA2 connected to the travel hydraulic motor 7 on one side and the path length of the travel hydraulic motor oil circuit 24MB1+24MB2 connected to the travel hydraulic motor 7 on the other side are equal to each other, and the inner diameters of the travel hydraulic motor oil circuits 24MA1, 24MA2, 24MB1, and 24MB2 are also the same.

[0042] The swing spool bore 25 is provided with swing motor ports 25a1 and 25a2, respectively, near the middle portion and the front surface 20a of the valve body 20. The swing motor port 25a1, located in the middle portion of the swing spool bore 25, extends from the side portion facing the right side surface 20d (as viewed from the front surface 20a of the valve body 20) toward the side surface 20d, then curves toward the front surface 20a, opening at the front surface 20a of the valve body 20. The swing motor port 25a2, located near the front surface 20a of the valve body 20, extends from the side portion facing the left side surface 20c (as viewed from the front surface 20a of the valve body 20) toward the side surface 20c, then curves toward the front surface 20a of the valve body 20, opening at the front surface 20a of the valve body 20. The two swing motor ports 25a1 and 25a2 are each connected to a swing hydraulic motor oil passage 25M, which communicates with the supply port 8a of the swing hydraulic motor 8.

[0043] Separate spool valves are provided in the cylinder spool bore 23, the travel spool bore 24, and the swing spool bore 25, respectively. Although not explicitly shown in the figure, the spool valves move axially when pilot pressure is applied from a separate EPC valve (electromagnetic proportional control valve). More specifically, the cylinder spool valve (working implement spool valve) 33 provided in the cylinder spool bore 23 switches the connection between the pump oil passages 21A and 21B and the cylinder port 23a by axial movement, forming a cylinder directional switching valve 33V. Similarly, the travel spool valve 34 provided in the travel spool bore 24 switches the connection between the pump oil passages 21A and 21B and the travel motor ports 24a1 and 24a2 by axial movement, forming a travel directional switching valve 34V. The rotary spool valve 35, disposed in the rotary spool valve hole 25, switches the intermittent state between the pump oil passage 21A and the rotary motor ports 25a1 and 25a2 by axial movement, thereby forming a rotary direction switching valve 35V via the rotary spool valve hole 25. Although not explicitly shown in the figure, multiple EPC valves corresponding to the respective spool valves 33, 34, and 35 are housed in a housing box EPCB provided on the rear surface 20b of the valve body 20.

[0044] In addition, a unit block 41 of the merging and diverting switching unit 40 is provided on the upper surface 20e of the valve body 20. The unit block 41 is large enough to simultaneously cover the openings of the two pump oil passages 21A and 21B opening on the upper surface 20e of the valve body 20, and has a merging and diverting oil passage 42 and a valve core hole 43 inside. The merging and diverting oil passages 42 extend in the left-right direction inside the unit block 41, and then each end bends downward and opens on the lower surface of the unit block 41. The merging and diverting oil passages 42 are connected to the upper ends of the pump oil passages 21A and 21B respectively via the lower end opening. The valve core hole 43 extends linearly in the front-to-back direction and is connected to the merging and diverting oil passage 42 by penetrating the middle portion of the portion extending left and right in the merging and diverting oil passage 42. Both ends of the valve core hole 43 are closed. A spool valve 44 for merging and diverting is provided in the valve core hole 43. The merging and splitting spool 44 moves in the axial direction when a pilot pressure is applied from the EPC valve, thereby switching the intermittent state of the merging and splitting oil passage 42 , and forming a merging and splitting switching valve 44V via the spool hole 43 .

[0045] The hydraulic valve device 1 described above is mounted on the upper slewing body 3, forward of the engine 10 and approximately in the left-right center, with the front surface 20a of the valve body 20 facing forward of the work machine and the upper surface 20e facing upward. In a work machine equipped with this hydraulic valve device 1, operating an operating lever (not shown) appropriately actuates the corresponding spool valves 33, 34, 35, and 44 via the EPC valve, changing the supply of oil from the hydraulic pump 9 to the hydraulic devices 7, 8, 11, and 12. For example, when the cylinder spool valve 33, located in the upper right portion when viewed from the front surface 20a of the valve body 20, is actuated to establish communication between the pump oil passage 21B and the cylinder port 23a, oil from the hydraulic pump 9 is supplied to the rod chamber 11H of the boom hydraulic cylinder 11 via the pump oil passage 21B, the cylinder port 23a, and the boom rod oil passage 11Ha. As a result, the boom hydraulic cylinder 11 retracts, enabling the distal end of the boom 4 to move downward relative to the work machine. Similarly, when the cylinder spool valve 33, located in the upper left portion when viewed from the front surface 20a of the valve body 20, is actuated to connect the pump oil passage 21A and the cylinder port 23a, oil from the hydraulic pump 9 is supplied to the bottom chamber 12B of the arm hydraulic cylinder 12 via the pump oil passage 21A, the cylinder port 23a, and the arm bottom oil passage 12Ba. As a result, the arm hydraulic cylinder 12 extends, enabling the distal end of the arm 5 to be pulled closer to the upper swing unit 3 relative to the work implement.

[0046] During this time, while the merging / splitting oil passage 42 is blocked by the merging / splitting spool valve 44, oil is supplied to the hydraulic cylinders 11 and 12 via either pump oil passage 21A or 21B. Conversely, when the merging / splitting oil passage 42 is connected by the merging / splitting spool valve 44, oil supplied from one hydraulic pump 9 to one pump oil passage 21A can be combined with oil supplied from the other hydraulic pump 9 to the other pump oil passage 21B in the valve body 20. This allows oil to be supplied from the other pump oil passage 21B to the cylinder port 23a connected to the one pump oil passage 21A, accelerating the operation of the hydraulic cylinders 11 and 12. Furthermore, according to the hydraulic valve device 1 described above, a merging / diverging switching valve 44V, comprising a merging / diverging spool valve 44, is provided in the merging / diverging oil passage 42 connecting the upper ends of the respective pump oil passages 21A and 21B. Furthermore, a cylinder spool valve 33 is connected to each pump oil passage 21A and 21B at a portion located above the connection with the pump ports 22A and 22B. Therefore, oil passing through the merging / diverging switching valve 44V does not pass through the travel spool valve 34 or the swing spool valve 35, which are located below the connection with the pump ports 22A and 22B, before reaching the target cylinder spool valve 33. Furthermore, oil passing through the merging / diverging switching valve 44V does not merge with oil supplied from the other hydraulic pump 9 before reaching the target cylinder spool valve 33, thereby suppressing pressure loss in the oil passage. As a result, a larger amount of oil can be efficiently supplied to the target cylinder spool valve 33 while minimizing pressure loss.

[0047] On the other hand, operating the operating lever to supply oil to the travel hydraulic motor 7 allows the work machine to travel via the crawler tracks 6. Supplying oil to the swing hydraulic motor 8 allows the upper swing unit 3 to swing relative to the lower travel unit 2. In the hydraulic valve device 1 described above, a travel spool valve 34 is provided in each pump oil passage 21A, 21B, located below the connection with the pump ports 22A, 22B. The oil path from the pump ports 22A, 22B to each travel spool valve 34 is identical. Furthermore, the travel spool valve 34 is initially connected to the portion below the pump ports 22A, 22B, with no other spool valves 33, 35 present. In other words, the hydraulic valve device 1 eliminates problems caused by differences in the length of the oil path through the two travel spool valves 34, nor does it cause problems caused by differences in pressure loss. As a result, when the straight-moving operation is performed by the operating lever, the supply pressure and supply flow rate of oil to the two travel spool valves 34 can be made equal, thereby improving the straight-moving performance of the working machine to which it is applied.

[0048] Furthermore, in the above embodiment, a configuration is illustrated in which four cylinder spool valves 33 are provided as work implement spool valves corresponding to the boom 4 and arm 5 of the work machine. However, other work implement spool valves may be provided to form a hydraulic valve device. For example, in the above-described work machine, a hydraulic valve device may be configured in which bucket spool valves are provided corresponding to the bucket hydraulic cylinder for actuating the bucket 13 provided at the tip of the arm 5.

[0049] Furthermore, in the above-described embodiment, a working implement spool (cylinder spool 33) is provided in the pump oil passages 21A and 21B above the connection with the pump ports 22A and 22B on one side, while a travel spool 34 is provided below the connection with the pump ports 22A and 22B on the other side. However, the present invention is not limited to this configuration. Specifically, as long as the two travel spools 34 are connected to separate pump oil passages 21A and 21B at positions equidistant from the pump ports 22A and 22B without intervening other spools 33 and 35, the two travel spools 34 may be provided above the connection with the pump ports 22A and 22B. Alternatively, one travel spool 34 may be provided above the connection with the pump ports, while the other travel spool 34 may be provided below the connection with the pump ports. Furthermore, although separate hydraulic pumps 9 are connected to the pump oil passages 21A and 21B respectively, oil from a single hydraulic pump may be supplied to the pump oil passages.

[0050] Furthermore, in the above-described embodiment, the two pump oil passages 21A and 21B are connected to each other via the merging / diverging oil passage 42 having the merging / diverging switching valve 44V. However, the present invention does not necessarily require the merging / diverging oil passage 42 .

[0051] Description of reference numerals:

[0052] 1Hydraulic valve device

[0053] 7 Travel hydraulic motor

[0054] 9. Hydraulic pump

[0055] 11Hydraulic cylinder for boom

[0056] 12 Hydraulic cylinder for bucket arm

[0057] 20 valve body

[0058] 21A, 21B pump oil circuit

[0059] 22A, 22B pump ports

[0060] 33 cylinder slide valve

[0061] 34 Travel slide valve

[0062] 42 split oil line

[0063] 44V combining and diverting switching valve.

Claims

1. A hydraulic valve device, which is interposed between a hydraulic device and a hydraulic pump, and controls the supply of oil from the hydraulic pump to the hydraulic device by actuating a slide valve provided in a valve body, wherein: The valve body has: A separate travel slide valve, which is provided corresponding to the two travel hydraulic devices; a working device slide valve provided corresponding to the working device hydraulic device; and Two pump oil circuits connected to the hydraulic pump via pump ports, The two travel slide valves are connected to separate pump oil passages at positions equidistant from the pump port without intervening other slide valves.

2. The hydraulic valve device according to claim 1, characterized in that: The two pump oil passages are provided on the valve body in parallel with each other. The pump port is arranged in the middle of each pump oil circuit. The working implement slide valve is connected to a portion of the pump oil passage located on one side of the pump port, and the travel slide valve is connected to a portion of the pump oil passage located on the other side of the pump port.

3. The hydraulic valve device according to claim 1, characterized in that: The ends of either one of the two pump oil passages are connected to each other via a merging and splitting oil passage having a merging and splitting switching valve.

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