Hydraulic valve apparatus

Abstract

In order to efficiently reclaim oil while suppressing an increase in size, a valve body 30a is provided with a first spool 41A which controls the supply of oil to a bottom chamber 12 of a hydraulic cylinder 10 for an arm and a second spool 41B which controls the supply of oil to a rod chamber 11, the valve body 30a is provided with an axial bottom oil passage portion 43A2 of a bottom oil passage 43A such that the axial bottom oil passage portion 43A2 is parallel to the axial direction of a second arm spool hole 32 and alongside the second arm spool hole 32, the second arm spool hole 32 is provided with a reclamation port 32d, a reclaimed oil passage 46A which allows the passage of oil from the reclamation port 32d to the bottom oil passage 43A is provided between the reclamation port 32d and the axial bottom oil passage portion 43A2, and the reclamation port 32d is connected to a second meter-out port 32c when a first meter-in port 31b is connected to a first pump oil supply port 31a.

Description

Hydraulic Valve Device

[0001] The present invention relates to a hydraulic valve device equipped with a regeneration circuit that supplies oil discharged from one oil chamber of a hydraulic cylinder to the other oil chamber.

[0002] Some hydraulic valve devices that control the supply of oil to hydraulic cylinders are equipped with a regeneration circuit. This type of hydraulic valve device has the advantage that, for example, when retracting the operating rod of a hydraulic cylinder, in addition to the oil supplied from the hydraulic pump, oil discharged from the bottom chamber can be supplied (regenerated) to the rod chamber, enabling the operating rod to be retracted quickly and improving fuel efficiency (see, for example, Patent Document 1).

[0003] Japanese Patent Application Publication No. 8-100803

[0004] In the above-described hydraulic valve device, a first meter in port and a first meter out port are provided at one end of the spool, a first oil passage is provided from the first meter in port along the radial direction of the spool, and the first oil passage is connected to the bottom chamber of the hydraulic cylinder, and a second meter in port and a second meter out port are provided at the other end of the spool, and a second oil passage is provided from the second meter in port along the radial direction of the spool, and the second oil passage is connected to the rod chamber of the hydraulic cylinder.

[0005] The regeneration circuit described above is configured by providing a regeneration port at one end of the spool and a regeneration oil passage connecting the regeneration port and the second meter port. In other words, the regeneration oil passage is provided in a line on the spool from one end to the other along the axial direction of the spool.

[0006] To efficiently supply oil through the regeneration circuit, it is preferable to ensure a large cross-sectional area of ​​the regeneration oil passage while shortening the path length of the regeneration oil passage. However, because the regeneration circuit must be installed from one end of the spool to the other, it is difficult to shorten the path length. In addition, if the cross-sectional area is made large, the external dimensions of the valve body must be increased, which raises concerns about the device becoming larger.

[0007] In view of the above circumstances, an object of the present invention is to provide a hydraulic valve device that can efficiently regenerate oil while suppressing an increase in size.

[0008] In order to achieve the above object, the hydraulic valve device according to the present invention is provided with a valve body provided with a first spool that controls the supply of oil to a first oil chamber of a hydraulic cylinder and a second spool that controls the supply of oil to a second oil chamber of the hydraulic cylinder, a first spool hole that houses the first spool is provided with a first pump oil supply port connected to a hydraulic pump, first meter-in and first meter-out ports that are connected to the first oil chamber through a first oil passage, and a first tank port that is connected to a tank, and a second spool hole that houses the second spool is provided with a second pump oil supply port that is connected to the hydraulic pump, a second meter-in port and a second meter-out port connected to the second oil chamber through a second oil passage, and a second tank port connected to a tank, the first oil passage having a first oil passage portion parallel to the axial direction of the second spool hole and aligned with the second spool hole, a regeneration port being provided in the second spool hole, and a regeneration oil passage being provided between the regeneration port and the first oil passage portion to allow oil to pass from the regeneration port to the first oil passage portion, the regeneration port being connected to the second meter-out port when oil is discharged from the second oil chamber.

[0009] According to the present invention, the first oil passage portion of the first oil passage is arranged parallel to the axial direction of the second spool hole and aligned with the second spool hole, so that the path length of the regeneration oil passage connecting the regeneration port provided in the second spool hole and the first oil passage portion can be shortened. This not only makes it possible to prevent an increase in the external dimensions of the valve body even when a large cross-sectional area of ​​the regeneration oil passage is ensured, but is also preferable from the viewpoint of the strength of the valve body.

[0010] FIG. 1 is a diagram showing a hydraulic drive circuit to which a hydraulic valve device according to an embodiment of the present invention is applied. FIG. 2 is a side view of a work machine equipped with a hydraulic cylinder controlled by the hydraulic drive circuit shown in FIG. 1. FIG. 3 is a perspective view schematically showing a main portion of a hydraulic valve device applied to the hydraulic drive circuit of FIG. 1. FIG. 4 is a perspective view schematically showing a main portion of the hydraulic valve device shown in FIG. 3 from a different angle. FIG. 5 is a perspective view schematically showing a main portion of the hydraulic valve device shown in FIG. 3 from a different angle. FIG. 6 is a diagram schematically showing a main portion of the hydraulic valve device shown in FIG. 3 from the front side. FIG. 7 is a diagram showing the appearance of a hydraulic valve device applied to the hydraulic drive circuit of FIG. 1, as seen from the front side. FIG. 8 is a cross-sectional view taken along line Y-Y in FIG. 7. FIG. 9 is a cross-sectional view taken along line Z-Z in FIG. 7. FIG. 10 is a cross-sectional view taken along line X-X in FIG. 8.

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a hydraulic valve device according to the present invention will be described in detail below with reference to the accompanying drawings.

[0012] 1 shows a hydraulic drive circuit to which a hydraulic valve device according to an embodiment of the present invention is applied. The hydraulic drive circuit shown here is for driving two hydraulic cylinders 10, 20 with oil supplied from two hydraulic pumps 1A, 1B.

[0013] The hydraulic pumps 1A, 1B are variable displacement pumps whose displacement volume changes by changing the tilt angle of the swash plate or inclined axis. The hydraulic drive circuit of this embodiment uses two hydraulic pumps 1A, 1B having the same configuration and the same size. In the following, when distinguishing between the two, the one on the left side of Figure 1 will be referred to as the first hydraulic pump 1A and the one on the right side will be referred to as the second hydraulic pump 1B.

[0014] The hydraulic cylinders 10, 20 reciprocate the actuating rods relative to the cylinder bodies by selectively supplying oil to their respective rod chambers and bottom chambers. In this embodiment, as shown in FIG. 2 , the arm hydraulic cylinder 10 and boom hydraulic cylinder 20 provided on one work machine are the targets of oil supply control. That is, the work machine includes a boom BM and an arm AM. The boom BM is rotatably supported at its base end on an upper rotating body JS by a horizontal boom shaft S1. The arm AM is rotatably supported at its base end on the tip of the boom BM by an arm shaft S2 provided parallel to the boom shaft S1. The arm hydraulic cylinder 10 is interposed between the boom BM and the arm AM, and the boom hydraulic cylinder 20 is interposed between the upper rotating body JS and the boom BM. The arm hydraulic cylinder 10 and the boom hydraulic cylinder 20 are each a single-rod, double-acting type equipped with a single actuating rod.

[0015] As shown in Figure 1, the hydraulic drive circuit is provided with a hydraulic valve device 30 between hydraulic pumps 1A, 1B and hydraulic cylinders 10, 20. The hydraulic valve device 30 has an arm direction switching valve 2A that selectively connects the first hydraulic pump 1A to the rod chamber (second oil chamber) 11 and the bottom chamber (first oil chamber) 12 of the arm hydraulic cylinder 10, and a boom direction switching valve 2B that selectively connects the second hydraulic pump 1B to the rod chamber (first oil chamber) 21 and the bottom chamber (second oil chamber) 22 of the boom hydraulic cylinder 20. In this hydraulic valve device 30, a valve body 30a is provided with two oil supply passages 3A, 3B, a tank oil passage 4, and four spools 41A, 41B, 42A, 42B.

[0016] The valve body 30a is shaped like a single block, and is configured in a substantially rectangular parallelepiped shape, as shown, for example, in FIGS. 3 to 6. The two oil supply passages 3A, 3B are linear cavities formed inside the valve body 30a with the same inner diameter and parallel axes. The two oil supply passages 3A, 3B are connected to the respective hydraulic pumps 1A, 1B described above, and are capable of supplying oil. For convenience, the following description will be given assuming that the two oil supply passages 3A, 3B are arranged along the vertical direction of the valve body 30a and offset toward the rear side of the valve body 30a. When distinguishing between the two oil supply passages 3A, 3B, the one connected to the first hydraulic pump 1A will be referred to as the first oil supply passage 3A, and the one connected to the second hydraulic pump 1B will be referred to as the second oil supply passage 3B. Although not shown in the figure, the tank oil passage 4 is a linear cavity formed inside the valve body 30a, and is provided along the top and bottom of the valve body 30a and in a position offset toward the front side. The tank oil passage 4 is connected to the tank T as shown in Figure 1.

[0017] The four spools 41A, 41B, 42A, and 42B are arranged in pairs to control the supply of oil to one hydraulic cylinder 10 or 20, and are disposed in the valve body 30a as shown in Figures 3 to 6. As shown in Figures 8 and 9, the spools 41A, 41B, 42A, and 42B are cylindrical with multiple lands divided by annular grooves. These spools 41A, 41B, 42A, and 42B are disposed parallel to one another with their respective axes perpendicular to the axial direction of the oil supply passages 3A and 3B, and are disposed in individual spool holes 31, 32, 33, and 34 provided in the valve body 30a so as to be movable along their respective axes.

[0018] 1, 5, and 7, in this embodiment, two spools (hereinafter referred to as arm spools 41A and 41B when distinguished) constituting the arm direction switching valve 2A are arranged vertically side by side along the axial direction of the first oil supply passage 3A, and two spools (hereinafter referred to as boom spools 42A and 42B when distinguished) constituting the boom direction switching valve 2B are arranged vertically side by side along the axial direction of the second oil supply passage 3B. These two arm spools 41A and 41B and two boom spools 42A and 42B are arranged horizontally side by side. Hereinafter, the arm spool located at the upper left when viewed from the front side will be referred to as the first arm spool (first spool) 41A, and the arm spool located at the lower left will be referred to as the second arm spool (second spool) 41B. Similarly, the boom spool located at the upper right when viewed from the front side is called the first boom spool (first spool) 42A, and the boom spool located at the lower right is called the second boom spool (second spool) 42B.

[0019] The first arm spool hole (first spool hole) 31 that houses the first arm spool 41A is provided with a first pump oil supply port 31a, a first meter in port 31b, a first meter-out port 31c, and a first tank port 31d, in this order from the end located on the lower side in Fig. 8. When the first arm spool 41A moves along the axial direction, the connection states of the first pump oil supply port 31a and the first tank port 31d to the first meter in port 31b and the first meter-out port 31c are switched.

[0020] More specifically, when the first arm spool 41A is disposed in the neutral position, the first meter port 31b and the first meter-out port 31c are both disconnected from the first pump oil supply port 31a and the first tank port 31d. When the first arm spool 41A moves from the neutral position to the lower side in FIG. 8 (left side in FIG. 1), the first meter port 31b is connected to the first pump oil supply port 31a, while the first meter-out port 31c and the first tank port 31d remain disconnected. When the first arm spool 41A moves from the neutral position to the upper side in FIG. 8 (right side in FIG. 1), the first meter port 31b remains disconnected, while the first meter-out port 31c and the first tank port 31d are connected.

[0021] The first meter in port 31b and the first meter-out port 31c are each connected to the bottom chamber 12 of the arm hydraulic cylinder 10 through a bottom oil passage (first oil passage) 43A. A load check valve 43Aa that allows oil to pass only to the bottom chamber 12 is provided in the bottom oil passage 43A that leads from the first meter in port 31b to the rod chamber 11. As shown in FIGS. 3 to 6 and 8, the bottom oil passage 43A includes a radial bottom oil passage portion 43A1 that is provided from the first meter in port 31b and the first meter-out port 31c along the radial direction of the first arm spool bore 31, and an axial bottom oil passage portion (first oil passage portion) 43A2 that is provided from the end of the radial bottom oil passage portion 43A1 in parallel to the axial direction of the first arm spool bore 31 and leads to the front surface of the valve body 30a. The axial bottom oil passage portion 43A2 is located above the second arm spool hole (second spool hole) 32 that accommodates the second arm spool 41B, and is arranged side by side with respect to the left and right of the first arm spool hole 31. The first pump oil supply port 31a is connected to the first supply oil passage 3A via a branch oil supply passage 44, and the first tank port 31d is connected to the tank oil passage 4 via a drain oil passage 45.

[0022] The second arm spool hole 32 is provided with a second pump oil supply port 32a, a second meter port 32b, a second meter-out port 32c, a regeneration port 32d, and a second tank port 32e in this order from the end located on the lower side in Fig. 9. When the second arm spool 41B moves along the axial direction, the connection states of the second pump oil supply port 32a and the second tank port 32e to the second meter port 32b and the second meter-out port 32c are switched.

[0023] More specifically, when the second arm spool 41B is positioned in the neutral position, the second meter port 32b and the second meter-out port 32c are all blocked from the second pump oil supply port 32a, the regeneration port 32d, and the second tank port 32e. When the second arm spool 41B moves from the neutral position to the lower side in FIG. 9 (left side in FIG. 1), the second meter-out port 32c is connected to the regeneration port 32d and the second tank port 32e, while the second meter port 32b and the second pump oil supply port 32a remain blocked. When the second arm spool 41B moves from the neutral position to the upper side in FIG. 9 (right side in FIG. 1), the second meter-out port 32c and the regeneration port 32d remain blocked, while the second meter port 32b and the second pump oil supply port 32a are connected.

[0024] The second meter port 32b and the second meter-out port 32c are each connected to the rod chamber 11 of the arm hydraulic cylinder 10 through a rod oil passage (second oil passage) 43B. A load check valve 43Ba that allows oil to pass only to the rod chamber 11 is provided in the rod oil passage 43B from the second meter port 32b to the rod chamber 11. As shown in Figures 3 to 6 and 10, the rod oil passage 43B includes a radial rod oil passage portion 43B1 provided from the second meter port 32b and the second meter-out port 32c along the radial direction of the second arm spool hole 32, and an axial rod oil passage portion (second oil passage portion) 43B2 provided from the end of the radial rod oil passage portion 43B1 in parallel to the axial direction of the second arm spool hole 32 to reach the front surface of the valve body 30a. The axial rod oil passage portion 43B2 is located below the axial bottom oil passage portion 43A2 and is arranged side by side with respect to the second arm spool hole 32. The second pump oil supply port 32a is connected to the first oil supply passage 3A via a branch oil supply passage 44, and the second tank port 32e is connected to the tank oil passage 4 via a drain oil passage 45.

[0025] 3 to 6 and 10, the regeneration port 32d of the second arm spool hole 32 is connected to the axial bottom oil passage portion 43A2 of the bottom oil passage 43A through a regeneration oil passage 46A provided in the valve body 30a. The regeneration oil passage 46A is provided so as to slope upward from the regeneration port 32d in a direction gradually approaching the axial bottom oil passage portion 43A2, and is connected to the bottom oil passage 43A at a portion downstream of the load check valve 43Aa. A regeneration check valve 46Aa is provided in the regeneration oil passage 46A, which only allows oil to pass from the regeneration port 32d to the bottom oil passage 43A.

[0026] The first boom spool hole (first spool hole) 33 that houses the first boom spool 42A is provided with a first pump oil supply port 33a, a first meter in port 33b, a first meter-out port 33c, and a first tank port 33d in this order from the end located on the lower side in Fig. 8. When the first boom spool 42A moves along the axial direction, the connection states of the first pump oil supply port 33a and the first tank port 33d to the first meter in port 33b and the first meter-out port 33c are switched.

[0027] More specifically, when the first boom spool 42A is disposed in the neutral position, the first meter port 33b and the first meter-out port 33c are both disconnected from the first pump oil supply port 33a and the first tank port 33d. When the first boom spool 42A moves from the neutral position to the lower side in FIG. 8 (to the right side in FIG. 1), the first meter port 33b is connected to the first pump oil supply port 33a, while the first meter-out port 33c and the first tank port 33d remain disconnected. When the first boom spool 42A moves from the neutral position to the upper side in FIG. 8 (to the left side in FIG. 1), the first meter port 33b remains disconnected, while the first meter-out port 33c and the first tank port 33d are connected.

[0028] The first meter in port 33b and the first meter-out port 33c are each connected to the rod chamber 21 of the boom hydraulic cylinder 20 through a rod oil passage (first oil passage) 47B. A load check valve 47Ba that allows oil to pass only to the rod chamber 21 is provided in the rod oil passage 47B that leads from the first meter in port 33b to the rod chamber 21. As shown in Figures 3 to 6 and 8, the rod oil passage 47B has a radial rod oil passage portion 47B1 provided from the first meter in port 33b and the first meter-out port 33c along the radial direction of the first boom spool hole 33, and an axial rod oil passage portion (first oil passage portion) 47B2 provided from the end of the radial rod oil passage portion 47B1 in parallel to the axial direction of the first boom spool hole 33 to reach the front surface of the valve body 30a. The axial rod oil passage portion 47B2 is located above the second boom spool hole (second spool hole) 34 that accommodates the second boom spool 42B, and is arranged side by side on the left and right of the first boom spool hole 33. The first pump oil supply port 33a is connected to the second oil supply passage 3B via a branch oil supply passage 48, and the first tank port 33d is connected to the tank oil passage 4 via a drain oil passage 49.

[0029] The second boom spool hole 34 is provided with a second pump oil supply port 34a, a second meter port 34b, a second meter-out port 34c, a regeneration port 34d, and a second tank port 34e, in this order from the end located on the lower side in Fig. 9. When the second boom spool 42B moves in the axial direction, the connection states of the second pump oil supply port 34a and the second tank port 34e to the second meter port 34b and the second meter-out port 34c are switched.

[0030] More specifically, when the second boom spool 42B is disposed in the neutral position, the second meter port 34b and the second meter-out port 34c are all disconnected from the second pump oil supply port 34a, the regeneration port 34d, and the second tank port 34e. When the second boom spool 42B moves from the neutral position to the lower side in FIG. 9 (to the right side in FIG. 1), the second meter-out port 34c is connected to the regeneration port 34d and the second tank port 34e, while the second meter port 34b and the second pump oil supply port 34a remain disconnected. When the second boom spool 42B moves from the neutral position to the upper side in FIG. 9 (to the left side in FIG. 1), the second meter-out port 34c and the regeneration port 34d remain disconnected, while the second meter port 34b and the second pump oil supply port 34a are connected.

[0031] The second meter inlet port 34b and the second meter-out port 34c are each connected to the bottom chamber 22 of the boom hydraulic cylinder 20 via a bottom oil passage (second oil passage) 47A. A load check valve 47Aa that allows oil to pass only to the bottom chamber 22 is provided in the bottom oil passage 47A that leads from the second meter inlet port 34b to the bottom chamber 22. As shown in Figures 3 to 6 and 9, the bottom oil passage 47A has a radial bottom oil passage portion 47A1 that is provided from the second meter inlet port 34b and the second meter-out port 34c along the radial direction of the second boom spool hole 34, and an axial bottom oil passage portion (second oil passage portion) 47A2 that is provided from the end of the radial bottom oil passage portion 47A1 in parallel to the axial direction of the second boom spool hole 34 and leads to the front surface of the valve body 30a. The axial bottom oil passage portion 47A2 is located below the axial rod oil passage portion 47B2, and is arranged side by side on the left and right of the second boom spool hole 34. The second pump oil supply port 34a is connected to the second oil supply passage 3B via a branch oil supply passage 48, and the second tank port 34e is connected to the tank oil passage 4 via a drain oil passage 49.

[0032] 3 to 6 and 10, the regeneration port 34d of the second boom spool hole 34 is connected to the axial rod oil passage portion 47B2 of the rod oil passage 47B through a regeneration oil passage 46B provided in the valve body 30a. The regeneration oil passage 46B is provided so as to incline upward from the regeneration port 34d in a direction gradually approaching the axial rod oil passage portion 47B2, and is connected to the rod oil passage 47B at a portion downstream of the load check valve 47Aa. A regeneration check valve 46Ba is provided in the regeneration oil passage 46B, which only allows oil to pass from the regeneration port 34d to the rod oil passage 47B.

[0033] As is apparent from FIGS. 8 and 9 , each of the four spools 41A, 41B, 42A, and 42B is provided with a neutral spring 80 and a pressure chamber 81 at each end. The neutral spring 80 maintains each of the spools 41A, 41B, 42A, and 42B in a neutral position. The pressure chambers 81 accommodate the ends of the spools 41A, 41B, 42A, and 42B and are filled with oil. Although not shown in the drawings, each pressure chamber 81 is individually connected to a pilot oil passage for applying pilot pressure output from the operating valve. When the pilot pressure output in response to operation of the operating valve is applied to the pressure chamber 81 through the pilot oil passage, it presses the spools 41A, 41B, 42A, and 42B in the axial direction, allowing the spools 41A, 41B, 42A, and 42B to move against the spring force of the neutral spring 80. When the pilot pressure applied to the pressure chamber 81 is removed, the spring force of the neutral spring 80 returns the spools 41A, 41B, 42A, and 42B to their neutral positions. In this embodiment, an arm operation valve is provided so that the two arm spools 41A and 41B move in conjunction with each other in the same direction. Similarly, when the boom operation valve is operated, the two boom spools 42A and 42B move in conjunction with each other in the same direction.

[0034] In the hydraulic drive circuit configured as described above, when the arm spools 41A, 41B are positioned in the neutral position, the first meter port 31b, the first meter-out port 31c, the second meter port 32b, and the second meter-out port 32c are all blocked, as shown in Figure 1. Therefore, no oil flows through the rod chamber 11 and the bottom chamber 12 of the arm hydraulic cylinder 10, and the operating rod 14 maintains its current position relative to the cylinder body 13.

[0035] 1 by operating the operating valve from this state, oil supplied to the first oil supply passage 3A from the first hydraulic pump 1A is supplied to the rod chamber 11 of the arm hydraulic cylinder 10 through the branch oil feed passage 44, the second pump oil supply port 32a of the second arm spool 41B, the second meter port 32b, and the rod oil passage 43B. At the same time, oil in the bottom chamber 12 is discharged to the tank T through the bottom oil passage 43A, the first meter-out port 31c of the first arm spool 41A, the first tank port 31d, and the drain oil passage 45. Therefore, in the work machine, the operating rod 14 is retracted relative to the cylinder body 13 of the arm hydraulic cylinder 10, allowing the arm AM to be dumped.

[0036] Conversely, when the arm spools 41A, 41B are moved to the left in Figure 1 by operation of the operating valve, oil supplied from the first hydraulic pump 1A to the first oil supply passage 3A is supplied to the bottom chamber 12 of the arm hydraulic cylinder 10 through the branch oil feed passage 44, the first pump oil supply port 31a of the first arm spool 41A, the first meter port 31b, and the bottom oil passage 43A. At the same time, oil in the rod chamber 11 is discharged to the tank T through the rod oil passage 43B, the second meter-out port 32c of the second arm spool 41B, the second tank port 32e, and the drain oil passage 45. Therefore, in the work machine, the operating rod 14 advances relative to the cylinder body 13 of the arm hydraulic cylinder 10, allowing the arm AM to perform an excavation operation.

[0037] Similarly, when the boom spools 42A, 42B are disposed in the neutral position, the first meter port 33b, the first meter-out port 33c, the second meter port 34b, and the second meter-out port 34c are all blocked. Therefore, no oil flows through the rod chamber 21 and the bottom chamber 22 of the boom hydraulic cylinder 20, and the operating rod 24 maintains its current position relative to the cylinder body 23.

[0038] 1 by operating the operating valve from this state, oil supplied to second oil supply passage 3B from second hydraulic pump 1B is supplied to bottom chamber 22 of boom hydraulic cylinder 20 through branch oil feed passage 48, second pump oil supply port 34a of second boom spool 42B, second meter port 34b, and bottom oil passage 47A. At the same time, oil in rod chamber 21 is discharged to tank T through rod oil passage 47B, first meter-out port 33c of first boom spool 42A, first tank port 33d, and drain oil passage 49. Therefore, in the work machine, operating rod 24 advances relative to cylinder body 23 of boom hydraulic cylinder 20, allowing the boom BM to be raised.

[0039] Conversely, when boom spools 42A, 42B are moved to the right in Figure 1 by operation of the operating valve, oil supplied from second hydraulic pump 1B to second oil supply passage 3B is supplied to rod chamber 21 of boom hydraulic cylinder 20 through branch oil feed passage 48, first pump oil supply port 33a of first boom spool 42A, first meter port 33b, and rod oil passage 47B. At the same time, oil in bottom chamber 22 is discharged to tank T through bottom oil passage 47A, second meter-out port 34c of second boom spool 42B, second tank port 34e, and drain oil passage 49. Therefore, in the work machine, operating rod 24 is retracted relative to cylinder body 23 of boom hydraulic cylinder 20, allowing the boom BM to be lowered.

[0040] In the hydraulic valve device 30 described above, when the arm spools 41A, 41B move to the left in FIG. 1 , the regeneration port 32d is connected to the second meter-out port 32c. Therefore, oil discharged from the rod chamber 11 passes through the rod oil passage 43B, the second meter-out port 32c, the regeneration port 32d, the regeneration oil passage 46A, and the regeneration check valve 46Aa. This oil is supplied to the bottom chamber 12 in addition to the oil from the first hydraulic pump 1A. This allows the operating rod 14 to advance without generating negative pressure in the bottom chamber 12, enabling the arm AM to quickly perform an excavation operation. When the pressure in the bottom chamber 12 exceeds the pressure in the rod chamber 11, the regeneration check valve 46Aa remains closed, and oil from the rod chamber 11 is discharged to the tank T.

[0041] Similarly, when the boom spools 42A, 42B move to the right in FIG. 1 , the regeneration port 34d becomes connected to the second meter-out port 34c. Therefore, oil discharged from the bottom chamber 22 passes through the bottom oil passage 47A, the second meter-out port 34c, the regeneration port 34d, the regeneration oil passage 46B, and the regeneration check valve 46Ba. This oil is supplied to the rod chamber 21 in addition to the oil from the second hydraulic pump 1B. This allows the operating rod 24 to be retracted without creating negative pressure in the rod chamber 21, enabling the boom BM to be lowered quickly. If the pressure in the bottom chamber 22 exceeds the pressure in the rod chamber 21, the regeneration check valve 46Ba remains closed, and oil from the rod chamber 21 is discharged to the tank T.

[0042] Furthermore, as described above, in the arm direction switching valve 2A, the regeneration oil passage 46A can be provided to achieve the shortest path length by linearly connecting the second arm spool hole 32 and the bottom oil passage 43A (axial bottom oil passage portion 43A2), which are arranged side by side. In the boom direction switching valve 2B, the regeneration oil passage 46B can be provided to achieve the shortest path length by linearly connecting the second boom spool hole 34 and the rod oil passage 47B (axial rod oil passage portion 47B2), which are arranged side by side. As a result, even if the regeneration oil passages 46A and 46B each have a large cross-sectional area, there is no risk of the valve body 30a becoming larger or having strength problems. This reduces pressure loss, allowing for efficient oil regeneration, which also has the advantage of improving fuel efficiency.

[0043] In the above-described embodiment, a hydraulic valve device that controls the supply of oil to an arm hydraulic cylinder and a boom hydraulic cylinder of a work machine is exemplified, but the present invention can also be applied to other hydraulic cylinders. In this case, it is not necessarily required to target multiple hydraulic cylinders, and it may also be required to target a single hydraulic cylinder.

[0044] In the arm direction switching valve 2A, the first arm spool 41A and the axial rod oil passage portion 43B2 are arranged parallel to each other with respect to the axial bottom oil passage portion 43A2 of the bottom oil passage 43A, but it is sufficient that the second arm spool 41B (first arm spool hole 32) is arranged parallel to the axial bottom oil passage portion 43A2. Similarly, in the boom direction switching valve 2B, it is sufficient that the second boom spool 42B (second boom spool hole 34) is arranged parallel to the axial rod oil passage portion 47B2 of the rod oil passage 47B.

[0045] Furthermore, in the above-described embodiment, the two arm spools 41A, 41B are configured to move in the same direction and the two boom spools 42A, 42B are configured to move in the same direction, but the present invention is not limited to this. For example, with respect to the arm hydraulic cylinder 10, the first spool 41A may be positioned in the neutral position, and only the second spool 41B may be moved to the left in FIG. 1 so that the regeneration port 32d is connected to the second meter-out port 32c. In this state, oil is not supplied to the arm hydraulic cylinder 10 from the first hydraulic pump 1A, but oil discharged from the rod chamber 11 is supplied to the bottom chamber 12 through the regeneration oil passage 46A. Therefore, in the work machine, the operating rod 14 advances relative to the cylinder body 13 of the arm hydraulic cylinder 10, allowing the arm AM to perform an excavation operation.

[0046] Similarly, with respect to the boom hydraulic cylinder 20, with the first spool 42A disposed in the neutral position, only the second spool 42B may be moved to the right in Figure 1 so that the regeneration port 34d is connected to the second meter-out port 34c. In this state, oil is not supplied from the second hydraulic pump 1B to the boom hydraulic cylinder 20, but oil discharged from the bottom chamber 22 is supplied to the rod 21 through the regeneration oil passage 46B. Therefore, in the work machine, the operating rod 24 is retracted relative to the cylinder body 23 of the boom hydraulic cylinder 20, allowing the boom BM to be lowered.

[0047] DESCRIPTION OF SYMBOLS 1A, 1B Hydraulic pump 10 Arm hydraulic cylinder 11 Rod chamber (second oil chamber) 12 Bottom chamber (first oil chamber) 20 Boom hydraulic cylinder 21 Rod chamber (first oil chamber) 22 Bottom chamber (second oil chamber) 30 Hydraulic valve device 30a Valve body 31 First arm spool hole (first spool hole) 31a First pump oil supply port 31b First meter in port 31c First meter-out port 31d First tank port 32 Second arm spool hole (second spool hole) 32a Second pump oil supply port 32b Second meter in port 32c Second meter-out port 32d Regeneration port 32e Second tank port 33 First boom spool hole (first spool hole) 33a First pump oil supply port 33b First meter in port 33c First meter-out port 33d First tank port 34 Second boom spool hole (second spool hole) 34a Second pump oil supply port 34b Second meter-out port 34c Second meter-out port 34d Regeneration port 34e Second tank port 41A First arm spool (first spool) 41B Second arm spool (second spool) 42A First boom spool (first spool) 42B Second boom spool (second spool) 43A Bottom oil passage (first oil passage) 43A2 Axial bottom oil passage section (first oil passage section) 43B Rod oil passage (second oil passage) 43B2 Axial rod oil passage section (second oil passage section) 46A Regeneration oil passage 46B Regeneration oil passage 47A Bottom oil passage (second oil passage) 47A2 Axial bottom oil passage section (second oil passage section) 47B Rod oil passage (first oil passage) 47B2 Axial rod oil passage (first oil passage) AM Arm BM Boom T Tank

Claims

1. A valve body is provided with a first spool for controlling the supply of oil to a first oil chamber of a hydraulic cylinder, and a second spool for controlling the supply of oil to a second oil chamber of the hydraulic cylinder; a first spool hole that houses the first spool is provided with a first pump oil supply port connected to a hydraulic pump, a first meter-in port and a first meter-out port connected to the first oil chamber through a first oil passage, and a first tank port connected to a tank; a second spool hole that houses the second spool is provided with a second pump oil supply port connected to a hydraulic pump, a second meter-in port and a second meter-out port connected to the second oil chamber through a second oil passage, and a second tank port connected to a tank; the first oil passage has a first oil passage portion that is parallel to the axial direction of the second spool hole and aligned with the second spool hole; a regeneration port is provided in the second spool hole, and a regeneration oil passage is provided between the regeneration port and the first oil passage portion to allow oil to pass from the regeneration port to the first oil passage portion; The hydraulic valve device according to claim 1, wherein the regeneration port is connected to the second meter-out port when oil is discharged from the second oil chamber.

2. The hydraulic valve device as described in claim 1, characterized in that the first spool hole and the second spool hole are arranged in the valve body with their axes parallel to each other, and the second oil passage has a second oil passage portion that is parallel to the axial direction of the first spool hole and arranged in line with the first spool hole.

3. The hydraulic valve device according to claim 1, wherein the first oil passage is connected to a bottom chamber of an arm hydraulic cylinder that drives an arm of a working machine, and the second oil passage is connected to a rod chamber of the arm hydraulic cylinder.

4. A hydraulic valve device as described in claim 1, characterized in that the first oil passage is connected to a rod chamber of a boom hydraulic cylinder that drives a boom of a work machine, and the second oil passage is connected to a bottom chamber of the boom hydraulic cylinder.

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