Servo valve and fluid device

Abstract

To provide a servo valve and a fluid device, which can smoothly move a spool without widening a gap between a sleeve and the spool.SOLUTION: A servo valve includes a cylindrical sleeve 40, a cylindrical spool that is located inside the sleeve 40 and moves from a closed position to open a supply passage of a fluid, and a spring that is connected to the spool connected and holds the spool in the closed position. The sleeve 40 includes a hole forming portion 47 formed with a hole 47A through which the spring passes, and a groove 48 that makes displacement of the central axis P1 of the sleeve 40 with respect to the central axis of the spool at the time when the sleeve 40 is deformed, less than the gap between the sleeve 40 and the spool.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a servo valve and a fluid device. [Background technology]

[0002] In a servo valve as described in Patent Document 1, a spool is disposed in a sleeve, and the sleeve and the spool are connected by a spring. The spring holds the spool in a closed position. The servo valve is a device in which the supply path of the working fluid opens when the spool moves from the closed position. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 2,884,907 Summary of the Invention [Problem to be solved by the invention]

[0004] However, since servo valves are required to operate stably when pressure and flow rate fluctuate, the spool needs to move smoothly. On the other hand, it is difficult to widen the gap between the sleeve and the spool in order to satisfy the requirement of internal leakage. [Means for solving the problem]

[0005] A servo valve that solves the above problem comprises a cylindrical sleeve, a cylindrical spool located inside the sleeve and moving from a closed position to open a fluid supply path, and a spring that connects to the spool to keep the spool in the closed position, wherein the sleeve comprises a hole forming portion having a hole through which the spring passes, and a deformation suppression portion that suppresses the displacement of the central axis of the sleeve relative to the central axis of the spool when the sleeve is deformed to be less than the gap between the sleeve and the spool.

[0006] According to the above configuration, the deformation of the sleeve is not uniform along the circumference due to the presence of a hole in the sleeve through which the spring passes. Therefore, by providing a deformation suppressing portion in the sleeve, the amount of deformation of the sleeve can be made less than the gap between the sleeve and the spool. Therefore, the spool can be moved smoothly without widening the gap between the sleeve and the spool.

[0007] In the servo valve described above, it is preferable that the deformation suppression portion is provided at the center of the sleeve in the axial direction. In the servo valve described above, it is preferable that the deformation suppression portion includes a groove provided on the side where the hole is located.

[0008] In the servo valve described above, it is preferable that the deformation suppression portion includes a reinforcing portion provided on a side opposite to the side on which the hole is located. A servo valve that solves the above problem comprises a cylindrical sleeve, a cylindrical spool located inside the sleeve, and a spring that connects to the spool to keep the spool in a closed position, the spool comprising a hole forming portion having a hole for connecting the spring, and a deformation suppression portion that keeps the displacement of the central axis of the spool relative to the central axis of the sleeve when the spool is deformed to less than the gap between the sleeve and the spool.

[0009] According to the above configuration, the deformation of the spool is not uniform around the circumference due to the presence of a hole for connecting the spring to the spool. Therefore, by providing a deformation suppressing portion to the spool, the amount of deformation of the spool can be made less than the gap between the sleeve and the spool. Therefore, the spool can be moved smoothly without widening the gap between the sleeve and the spool.

[0010] In the servo valve described above, it is preferable that the deformation suppression portion is provided at the center of the spool in the axial direction. In the servo valve described above, it is preferable that the deformation suppression portion includes a recess provided on the side opposite to the side on which the hole is located.

[0011] In the servo valve described above, it is preferable that the deformation suppression portion includes a reinforcing portion provided on the side where the hole is located. In the servo valve described above, it is preferable that the deformation suppression portion offsets a central axis of the shaft connected to the portion having the hole toward the side having the hole.

[0012] A servo valve that solves the above problem comprises a cylindrical sleeve, a cylindrical spool located inside the sleeve and moving from a closed position to open a fluid supply path, and a spring that connects to the spool to keep the spool in the closed position, wherein the sleeve comprises a first hole forming portion having a first hole through which the spring passes, and a first deformation suppression portion that keeps the displacement of the central axis of the sleeve relative to the central axis of the spool when the sleeve is deformed less than the gap between the sleeve and the spool, and the spool comprises a second hole forming portion having a second hole for connecting the spring, and a second deformation suppression portion that keeps the displacement of the central axis of the spool relative to the central axis of the sleeve when the spool is deformed less than the gap between the sleeve and the spool.

[0013] According to the above configuration, the sleeve has a first hole through which the spring passes, so that the deformation of the sleeve is not uniform on the circumference. Therefore, by providing the first deformation suppressing portion on the sleeve, the deformation of the sleeve can be made less than the gap between the sleeve and the spool. Furthermore, the spool has a second hole through which the spring is connected, so that the deformation of the spool is not uniform on the circumference. Therefore, by providing the second deformation suppressing portion on the spool, the deformation of the spool can be made less than the gap between the sleeve and the spool. Therefore, the spool can be moved smoothly without widening the gap between the sleeve and the spool.

[0014] A fluid device that solves the above problem comprises a servo valve including a cylindrical sleeve, a cylindrical spool located inside the sleeve and moving from a closed position to open a fluid supply path, and a spring connected to the spool to keep the spool in the closed position, and an actuator driven by fluid supplied as the spool moves inside the sleeve, wherein the sleeve includes a hole forming portion having a hole through which the spring passes, and a deformation suppression portion that limits the displacement of the central axis of the sleeve relative to the central axis of the spool when the sleeve is deformed to less than the gap between the sleeve and the spool.

[0015] According to the above configuration, the deformation of the sleeve is not uniform on the circumference due to the presence of a hole in the sleeve through which the spring passes. Therefore, by providing a deformation suppressing portion in the sleeve, the amount of deformation of the sleeve can be made less than the gap between the sleeve and the spool. Therefore, the spool can be moved smoothly without widening the gap between the sleeve and the spool. As a result, the actuator can be driven smoothly.

[0016] A fluid device that solves the above problem comprises a servo valve including a cylindrical sleeve, a cylindrical spool located inside the sleeve, and a spring connected to the spool to keep the spool in a closed position, and an actuator that is driven by fluid supplied as the spool moves inside the sleeve, wherein the spool comprises a hole forming portion in which a hole for connecting the spring is formed, and a deformation suppression portion that keeps the displacement of the central axis of the spool relative to the central axis of the sleeve when the spool is deformed to less than the gap between the sleeve and the spool.

[0017] According to the above configuration, the deformation of the spool is not uniform around the circumference due to the presence of a hole for connecting the spring to the spool. Therefore, by providing a deformation suppressing portion to the spool, the amount of deformation of the spool can be made less than the gap between the sleeve and the spool. Therefore, the spool can be moved smoothly without widening the gap between the sleeve and the spool. As a result, the actuator can be driven smoothly. Effect of the Invention

[0018] According to the present invention, the spool can be moved smoothly without widening the gap between the sleeve and the spool. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of a fluid device including a servo valve. [Diagram 2] FIG. 4 is a perspective view showing a sleeve of a servo valve. [Diagram 3] FIG. 4 is a side view showing a sleeve of the servo valve. [Figure 4] FIG. 4 is a perspective view showing a spool of a servo valve. [Diagram 5] FIG. 4 is a side view showing a spool of a servo valve. [Figure 6] FIG. 4 is an axial cross-sectional view showing a state in which a spool is assembled to a sleeve of a servo valve. [Figure 7] FIG. 4 is a cross-sectional view showing a gap between a sleeve and a spool of a servo valve. [Figure 8] FIG. 13 is a side view showing a modified example of the sleeve of the servo valve. [Figure 9] FIG. 13 is a side view showing a modified example of the sleeve of the servo valve. [Figure 10] FIG. 13 is a side view showing a modified example of the sleeve of the servo valve. [Figure 11] FIG. 13 is a side view showing a modified example of the sleeve of the servo valve. [Figure 12] FIG. 13 is a side view showing a modified example of the spool of the servo valve. [Figure 13] FIG. 13 is a side view showing a modified example of the spool of the servo valve. [Figure 14] FIG. 13 is a side view showing a modified example of the spool of the servo valve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, one embodiment of a fluid device including a servo valve will be described with reference to FIGS. 1, the fluid device 1 includes a servo valve 2 and an actuator 70. The servo valve 2 can steplessly control the drive of the actuator 70 by hydraulic pressure. The servo valve 2 includes a nozzle 10, a receiver 20, a torque motor 30, and a spool valve 4.

[0021] The nozzle 10 has an inlet 11 and a discharge port 12. A first pump 3, which is a supply source that supplies the working fluid, is connected to the inlet 11. The nozzle 10 discharges the supplied working fluid from the discharge port 12 to a receiver 20.

[0022] The receiver 20 is formed with a left inlet 21 and a right inlet 22. The working fluid flows into the left inlet 21 and the right inlet 22 from the discharge port 12 of the nozzle 10. The receiver 20 is formed with a left flow path 23 and a right flow path 24. The left flow path 23 extends downward and left from the left inlet 21 and terminates at a left outlet 25. The right flow path 24 extends downward and right from the right inlet 22 and terminates at a right outlet 26. The left outlet 25 and the right outlet 26 are formed on the outer surface of the receiver 20 and connected to the spool valve 4.

[0023] The torque motor 30 includes a left coil 31, a right coil 32, an upper pole piece 33, a lower pole piece 34, and a magnetic rod 35. The upper pole piece 33 is formed in a substantially cylindrical shape. The lower pole piece 34 is formed in a substantially cylindrical shape, similar to the upper pole piece 33. The left coil 31 is housed in the upper pole piece 33 and the lower pole piece 34. The right coil 32 is housed in the upper pole piece 33 and the lower pole piece 34. The lower edge of the upper pole piece 33 faces the upper edge of the lower pole piece 34. The magnetic rod 35 extends substantially horizontally. The left and right ends of the magnetic rod 35 are located in the gap between the lower edge of the upper pole piece 33 and the upper edge of the lower pole piece 34.

[0024] Current is supplied to the left coil 31 and the right coil 32. Therefore, the upper pole piece 33 and the lower pole piece 34 function as magnets. When current is supplied to the left coil 31 and the right coil 32 such that the left end of the magnetic rod 35 is attracted to the upper pole piece 33 while the right end of the magnetic rod 35 is attracted to the lower pole piece 34, the magnetic rod 35 rotates clockwise. When current is supplied to the left coil 31 and the right coil 32 such that the left end of the magnetic rod 35 is attracted to the lower pole piece 34 while the right end of the magnetic rod 35 is attracted to the upper pole piece 33, the magnetic rod 35 rotates counterclockwise.

[0025] The spool valve 4 is connected to two pumps, a second pump 5A and a third pump 5B, and a tank 6. The spool valve 4 includes a sleeve 40, a spool 50, and a cantilever spring 60.

[0026] The sleeve 40 is a cylindrical member with both ends closed. The spool 50 is a columnar member. The spool 50 is disposed inside the sleeve 40. As a result, a flow path is formed inside the sleeve 40 through which the working fluid flows. The cantilever spring 60 is coupled to the nozzle 10 and is connected to the spool 50 through a hole 47A in the sleeve 40. The cantilever spring 60 applies a force to the spool 50 to keep the spool 50 in the closed position. When the spool 50 is in the closed position, the spool valve 4 blocks the supply path of the working fluid from the second pump 5A and the third pump 5B to the actuator 70. When the spool 50 moves from the closed position to the left or right, the spool valve 4 opens the supply path of the working fluid from the second pump 5A and the third pump 5B to the actuator 70.

[0027] The sleeve 40 has seven ports 61 to 67. The first port 61 is connected to the left outlet 25 of the receiver 20, and the working fluid flows between the first port 61 and the left outlet 25. The second port 62 is connected to the right outlet 26 of the receiver 20, and the working fluid flows between the second port 62 and the right outlet 26. The second pump 5A is connected to the third port 63, and supplies the working fluid. The third pump 5B is connected to the fourth port 64, and supplies the working fluid. The fifth port 65 is connected to the left port 73 of the actuator 70, and the working fluid flows between the fifth port 65 and the left port 73. The sixth port 66 is connected to the right port 74 of the actuator 70, and the working fluid flows between the sixth port 66 and the right port 74. The tank 6 is connected to the seventh port 67, and stores the working fluid.

[0028] The spool 50 includes four partitions 51, 52, 53, and 54 and a connecting shaft 55. The connecting shaft 55 connects the partitions 51, 52, 53, and 54 and extends substantially horizontally. The first partition 51 is formed at the left end of the connecting shaft 55. The second partition 52 is formed at the right end of the connecting shaft 55. The third partition 53 is located between the first partition 51 and the second partition 52. The fourth partition 54 is located between the second partition 52 and the third partition 53.

[0029] The four partitions 51, 52, 53, 54 divide the internal space of the sleeve 40 into five chambers 41, 42, 43, 44, 45. The first chamber 41 is formed at the leftmost part inside the sleeve 40. The second chamber 42 is formed at the rightmost part inside the sleeve 40. The third chamber 43 is formed between the first partition 51 and the third partition 53 inside the sleeve 40. The fourth chamber 44 is formed between the second partition 52 and the fourth partition 54 inside the sleeve 40. The fifth chamber 45 is formed between the third partition 53 and the fourth partition 54 inside the sleeve 40.

[0030] The actuator 70 includes a housing 71 and a movable piece 72. Two ports, a left port 73 and a right port 74, are formed in the housing 71. The left port 73 of the actuator 70 is connected to a fifth port 65 of the sleeve 40, and the working fluid flows between the left port 73 and the fifth port 65. The right port 74 of the actuator 70 is connected to a sixth port 66 of the sleeve 40, and the working fluid flows between the right port 74 and the sixth port 66.

[0031] The movable piece 72 includes a partition wall 72A and a rod 72B. The partition wall 72A divides the internal space of the housing 71 into a left chamber 75 and a right chamber 76. The left port 73 is connected to the left chamber 75. The right port 74 is connected to the right chamber 76. The rod 72B extends rightward from the partition wall 72A and protrudes outside the housing 71. The rod 72B is connected to another external device (not shown) disposed outside the housing 71.

[0032] Next, the structure of the sleeve 40 will be described in detail with reference to FIGS. As shown in Figs. 2 and 3, the sleeve 40 has a hole forming portion 47 in which a hole 47A is formed. The hole forming portion 47 is provided in the axial center portion 46 of the sleeve 40. The cantilever spring 60 passes through the hole 47A. The hole 47A of the hole forming portion 47 opens upward in the figure. Therefore, the hole forming portion 47 is located above the central axis P1 of the sleeve 40 in the figure. The outer diameter of the axial center portion 46 of the sleeve 40 is shorter than the outer diameter of the portion other than the central portion 46. The hole 47A corresponds to the first hole, and the hole forming portion 47 corresponds to the first hole forming portion.

[0033] In the outer periphery of the sleeve 40, a groove 48 is provided between the hole forming portion 47 and the portion other than the central portion 46. That is, the groove 48 is provided in the central portion 46 in the axial direction of the sleeve 40. The groove 48 is provided on the side where the hole 47A is located, in other words, on the upper side of the central axis P1 in the figure. The groove 48 is a portion having an outer diameter shorter than that of the hole forming portion 47. Here, when the hole forming portion 47 and the portion other than the hole forming portion 47 are connected with the same outer diameter, the central portion 46 of the sleeve 40 has a higher rigidity on the side where the hole forming portion 47 is provided, in other words, on the upper side of the central axis P1, than on the lower side of the central axis P1. Therefore, the groove 48 is provided so that the rigidity of the upper side of the central axis P1 of the sleeve 40 approaches the rigidity of the lower side of the central axis P1. As a result, the difference in rigidity between the upper and lower sides of the central axis P1 of the sleeve 40 is reduced, thereby suppressing deformation of the sleeve 40. The groove 48 functions as a deformation suppressing portion and a first deformation suppressing portion. Rigidity is the degree of resistance to deformation (dimensional change) due to force.

[0034] Next, the structure of the spool 50 will be described in detail with reference to FIGS. As shown in Figs. 4 and 5, the spool 50 has a hole forming portion 57 in which a hole 57A is formed. The hole forming portion 57 is provided in the axial center portion 56 of the spool 50. The cantilever spring 60 is connected to the hole 57A. The hole 57A of the hole forming portion 57 opens upward in the figure. The outer diameter of the hole forming portion 57 is longer than the outer diameter of the connecting shaft 55. The hole 57A corresponds to the second hole, and the hole forming portion 57 corresponds to the second hole forming portion.

[0035] The hole forming portion 57 is provided with a recess 58. That is, the recess 58 is provided in a central portion 56 in the axial direction of the spool 50. The recess 58 is provided on the side opposite to the side on which the hole 57A of the hole forming portion 57 is located. The recess 58 functions as a deformation suppressing portion and a second deformation suppressing portion.

[0036] 6, the spool 50 is disposed inside the sleeve 40. A cantilever spring 60 (not shown) is connected to the nozzle 10 and a hole 57A of the spool 50. A fastening screw (not shown) is provided in the center of the central axis P2 of the spool 50. The fastening screw fastens the cantilever spring 60, thereby fixing the cantilever spring 60 to the spool 50. It is noted that the cantilever spring 60 does not necessarily have to be fastened to the spool 50.

[0037] Conventionally, the sleeve and the spool are deformed by external loads and external hydraulic pressure, or by fastening the fastening screw. If the deformation of at least one of the sleeve and the spool becomes large, interference occurs when the spool moves relative to the sleeve, resulting in large resistance. In order to avoid this, it is possible to increase the gap between the sleeve and the spool, but it is preferable not to change the size of the gap in order to suppress leakage of the working fluid.

[0038] Therefore, the sleeve 40 is provided with a groove 48 as a deformation suppression portion. By providing the groove 48 on the side of the sleeve 40 where the hole 47A is located, the rigidity of the side where the hole 47A is located can be reduced. If the hole forming portion 47 is reinforced, the rigidity of the side where the hole 47A is located increases, so by reducing the rigidity with the groove 48, the difference in rigidity between each position in the center of the sleeve 40 in the axial direction can be reduced.

[0039] Further, the spool 50 is provided with a recess 58 as a deformation suppressing portion. By providing the recess 58 on the side opposite to the side where the hole 57A of the spool 50 is located, the rigidity on the side opposite to the side where the hole 57A is located can be reduced. Since the rigidity on the side where the hole 57A is located becomes low due to the presence of the hole 57A, the rigidity can be reduced by the recess 58 on the side opposite to the side where the hole 57A is located, and the difference in rigidity at each position in the axial center of the spool 50 can be reduced.

[0040] As a result, as shown in FIG. 7, when the sleeve 40 is deformed, the displacement D of the central axis P1 of the sleeve 40 with respect to the central axis P2 of the spool 50 becomes less than the gap W between the sleeve 40 and the spool 50 (D < W). Therefore, the groove 48 of the sleeve 40 functions as a deformation suppressing portion. Further, when the spool 50 is deformed, the displacement D of the central axis P2 of the spool 50 with respect to the central axis P1 of the sleeve 40 becomes less than the gap W between the sleeve 40 and the spool 50 (D < W). Therefore, the recess 58 of the spool 50 functions as a deformation suppressing portion. Here, if the displacement of the central axis P1, which is the amount of deformation of the sleeve 40 itself, is "D1", and the displacement of the central axis P2, which is the amount of deformation of the spool 50 itself, is "D2", the sum of the displacement D1 and the displacement D2 is the displacement D. This displacement D is less than the gap W between the sleeve 40 and the spool 50 (D = D1 + D2 < W). Note that the displacement D and the gap W in FIG. 7 are shown enlarged for the purpose of explanation.

[0041] Next, with reference to FIG. 1, the operation of the fluid device 1 including the servo valve 2 configured as described above will be described. As shown in FIG. 1, when the nozzle 10 moves leftward, the working fluid mainly flows from the discharge port 12 of the nozzle 10 into the left inlet 21 of the receiver 20. The working fluid that flows into the left inlet 21 then flows into the first chamber 41 through the left flow passage 23 of the receiver 20, the left outlet 25 of the receiver 20, and the first port 61 of the spool valve 4. As a result, the internal pressure of the first chamber 41 increases, and the spool 50 moves rightward from the closed position. During this time, the working fluid that was present in the second chamber 42 is ejected from the right inlet 22 through the second port 62 of the spool valve 4, the right outlet 26 of the receiver 20, and the right flow passage 24 of the receiver 20.

[0042] Thereafter, when the nozzle 10 returns to the neutral position, the working fluid discharged from the discharge port 12 of the nozzle 10 flows approximately evenly into the left inlet 21 and the right inlet 22 of the receiver 20. During this time, the force acting to the left of the spool 50 is greater than the force acting to the right of the spool 50 by the restoring force of the cantilever spring 60. Therefore, the spool 50 moves to the left and returns to the closed position.

[0043] When the nozzle 10 moves to the right, the working fluid mainly flows from the discharge port 12 of the nozzle 10 into the right inlet 22 of the receiver 20. The working fluid that flows into the right inlet 22 then flows into the second chamber 42 through the right flow passage 24 of the receiver 20, the right outlet 26 of the receiver 20, and the second port 62 of the spool valve 4. As a result, the internal pressure of the second chamber 42 increases, and the spool 50 moves leftward from the closed position. During this time, the working fluid that was present in the first chamber 41 is ejected from the left inlet 21 through the first port 61 of the spool valve 4, the left outlet 25 of the receiver 20, and the left flow passage 23 of the receiver 20.

[0044] Thereafter, when the nozzle 10 returns to the neutral position, the working fluid discharged from the discharge port 12 of the nozzle 10 flows approximately evenly into the left inlet 21 and the right inlet 22 of the receiver 20. During this time, the force acting to the right on the spool 50 is greater than the force acting to the left on the spool 50 by the restoring force of the cantilever spring 60. Therefore, the spool 50 moves to the right and returns to the closed position.

[0045] When the spool 50 is in the closed position, the third partition 53 closes the fifth port 65. At this time, the fourth partition 54 closes the port 66. The second pump 5A supplies high-pressure working fluid to the third chamber 43 through the third port 63. The third pump 5B supplies high-pressure working fluid to the fourth chamber 44 through the fourth port 64. When the spool 50 moves rightward from the closed position, the supply path of the working fluid from the third chamber 43 to the actuator 70 and the discharge path of the working fluid from the actuator 70 to the fifth chamber 45 are opened. When the spool 50 moves leftward from the closed position, the supply path of the working fluid from the fourth chamber 44 to the actuator 70 and the discharge path of the working fluid from the actuator 70 to the fifth chamber 45 are opened. Therefore, the outflow amount of the working fluid from the fifth port 65 and the sixth port 66 to the actuator 70 is adjusted by the left-right movement of the nozzle 10.

[0046] When the spool 50 moves rightward from the closed position, the working fluid supplied from the second pump 5A to the third chamber 43 through the third port 63 flows into the left chamber 75 through the fifth port 65 and the left port 73. Since the internal pressure of the left chamber 75 increases, the movable piece 72 moves rightward. During this time, the right chamber 76 communicates with the fifth chamber 45 through the right port 74 and the sixth port 66. The working fluid present in the right chamber 76 is pushed out of the right chamber 76 by the movable piece 72 moving rightward, and flows into the fifth chamber 45. The working fluid that flows into the fifth chamber 45 is then stored in the tank 6.

[0047] When the spool 50 moves leftward from the closed position, the working fluid supplied from the third pump 5B to the fourth chamber 44 through the fourth port 64 flows into the right chamber 76 through the sixth port 66 and the right port 74. Since the internal pressure of the right chamber 76 increases, the movable piece 72 moves leftward. During this time, the left chamber 75 communicates with the fifth chamber 45 through the left port 73 and the fifth port 65. The working fluid present in the left chamber 75 is pushed out of the left chamber 75 by the movable piece 72 moving leftward, and flows into the fifth chamber 45. The working fluid that has flowed into the fifth chamber 45 is then stored in the tank 6.

[0048] Next, the effects of this embodiment will be described. (1) The sleeve 40 has a hole 47A through which the cantilever spring 60 passes, so that the deformation of the sleeve 40 is not uniform around the circumference. Therefore, by providing the sleeve 40 with a groove 48 as a deformation suppressing portion, the amount of deformation of the sleeve 40 can be made less than the gap W between the sleeve 40 and the spool 50. Therefore, the spool 50 can be moved smoothly without widening the gap W between the sleeve 40 and the spool 50.

[0049] (2) By providing groove 48 in center portion 46 of sleeve 40 as a deformation suppressing portion, deformation of sleeve 40 in the axial direction can be suppressed from the center, and deformation of sleeve 40 in the entire axial direction can be efficiently suppressed.

[0050] (3) The rigidity of the side where the hole 47A is located can be reduced by providing the groove 48 on the side where the hole 47A is located of the sleeve 40. If the hole forming portion 47 is reinforced, the rigidity of the side where the hole 47A is located increases, so the rigidity can be reduced by using the groove 48, thereby reducing the difference in rigidity between each position in the center of the sleeve 40 in the axial direction.

[0051] (4) The deformation of the spool 50 is not uniform around the circumference due to the presence of the hole 57A for connecting the cantilever spring 60 in the spool 50. For this reason, by providing the recess 58 as a deformation suppressing portion in the spool 50, the amount of deformation of the spool 50 can be made less than the gap W between the sleeve 40 and the spool 50. Therefore, the spool 50 can be moved smoothly without widening the gap W between the sleeve 40 and the spool 50.

[0052] (5) By providing the recess 58 as a deformation suppressing portion in the center portion 56 of the spool 50, the axial deformation of the spool 50 can be suppressed from the center, and the deformation of the entire axial direction of the spool 50 can be efficiently suppressed.

[0053] (6) By providing recess 58 on the side opposite to the side where hole 57A of spool 50 is located, it is possible to reduce the rigidity on the side opposite to the side where hole 57A is located. Since the presence of hole 57A reduces the rigidity on the side where hole 57A is located, recess 58 on the side opposite to the side where hole 57A is located can reduce the rigidity and reduce the difference in rigidity between each position in the center of spool 50 in the axial direction.

[0054] (Other embodiments) The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0055] In the above embodiment, instead of the groove 48 provided in the sleeve 40, a plurality of holes may be provided in the sleeve 40 as a deformation suppressing portion. As shown in FIG. 8, the hole forming portion 47 provided in the center portion 46 of the sleeve 40 is connected to the outer circumferential portion other than the center portion 46. A plurality of holes 148 are provided in a line in the circumferential direction on both sides of the hole 47A on the side where the hole 47A of the hole forming portion 47 is located. According to the above configuration, the plurality of holes 148 can reduce the rigidity and reduce the difference in rigidity between each position in the center of the sleeve 40 in the axial direction, and the deformation amount of the sleeve 40 can be made less than the gap W between the sleeve 40 and the spool 50.

[0056] In the above embodiment, instead of the groove 48 provided in the sleeve 40, a long hole may be provided in the sleeve 40 as a deformation suppressing portion. As shown in FIG. 9, the hole forming portion 47 provided in the center portion 46 of the sleeve 40 is connected to the outer circumferential portion other than the center portion 46. On both sides of the hole 47A on the side where the hole 47A of the hole forming portion 47 is located, a long hole 248 extending in the circumferential direction is provided. According to the above configuration, the long hole 248 can reduce the rigidity and reduce the difference in rigidity between each position in the center of the sleeve 40 in the axial direction, and the deformation amount of the sleeve 40 can be made less than the gap W between the sleeve 40 and the spool 50.

[0057] In the above embodiment, instead of the groove 48 provided in the sleeve 40, the hole 47A may be enlarged as a deformation suppression portion. As shown in Fig. 10, the hole forming portion 147 provided in the central portion 46 of the sleeve 40 is connected to the outer periphery other than the central portion 46. An enlarged hole 147A enlarged to a size equivalent to the central portion 46 is provided in the hole forming portion 147. According to the above configuration, the enlarged hole 147A can reduce the rigidity and reduce the difference in rigidity between each position in the axial center of the sleeve 40, and the amount of deformation of the sleeve 40 can be made less than the gap W between the sleeve 40 and the spool 50.

[0058] In the above embodiment, instead of the groove 48 provided in the sleeve 40, a reinforcing portion may be provided on the side opposite to the side where the hole 47A is located as a deformation suppressing portion. As shown in FIG. 11, the hole forming portion 47 provided in the center portion 46 of the sleeve 40 is connected to the outer periphery other than the center portion 46. Since the hole forming portion 47 is provided near the upper side of the sleeve 40 in the figure, the reinforcing portion 149 is provided near the lower side of the sleeve 40 in the figure. The reinforcing portion 149 is indicated by dots in the figure. The reinforcing portion 149 is connected to the outer periphery other than the center portion 46. According to the above configuration, by providing the reinforcing portion 149 on the side opposite to the side where the hole 47A of the sleeve 40 is located, the rigidity of the side opposite to the side where the hole 47A is located can be increased. If the hole forming portion 47 is reinforced, the rigidity of the side where the hole 47A is located increases, so the reinforcing portion 149 can reduce the rigidity of the side opposite to the side where the hole 47A is located, thereby reducing the difference in rigidity between the positions.

[0059] In the above embodiment, instead of the recess 58 provided in the spool 50, a hole may be provided as the deformation suppression portion. As shown in Fig. 12, instead of the recess 58, a hole 158 is provided on the side opposite to the side where the hole 57A of the hole forming portion 57 is located. According to the above configuration, the hole 158 can reduce the rigidity and reduce the difference in rigidity between each position in the center of the spool 50 in the axial direction, and the amount of deformation of the spool 50 can be made less than the gap W between the sleeve 40 and the spool 50.

[0060] In the above embodiment, instead of the recess 58 provided in the spool 50, a reinforcing portion may be provided on the side where the hole 57A is located as a deformation suppressing portion. As shown in FIG. 13, a reinforcing portion 155 is provided on the upper side of the connecting shaft 55 between the hole forming portion 57 and the third partition wall 53 in the figure. The reinforcing portion 155 is integral with the connecting shaft 55 and is connected to the hole forming portion 57 and the third partition wall 53. Similarly, a reinforcing portion 155 is provided on the upper side of the connecting shaft 55 between the hole forming portion 57 and the fourth partition wall 54 in the figure. The reinforcing portion 155 is integral with the connecting shaft 55 and is connected to the hole forming portion 57 and the fourth partition wall 54. According to the above configuration, by providing the reinforcing portion 155 on the side where the hole 57A of the spool 50 is located, the rigidity of the side where the hole 57A is located can be increased. Since the presence of the hole 57A reduces the rigidity of the side where the hole 57A is located, the reinforcing portion 155 can increase the rigidity and reduce the difference in rigidity between the positions.

[0061] In the above embodiment, instead of the recess 58 provided in the spool 50, the central axis of the shaft connected to the hole forming portion 57 having the hole 57A may be eccentric toward the side where the hole 57A is located as a deformation suppressing portion. As shown in FIG. 14, the connecting shaft 255 between the hole forming portion 57 and the third partition wall 53 is eccentric toward the upper side in the figure. The central axis of the connecting shaft 255 is located on the upper side in the figure where the hole 57A is located. Similarly, the connecting shaft 255 between the hole forming portion 57 and the fourth partition wall 54 is eccentric toward the upper side in the figure. The central axis of the connecting shaft 255 is located on the upper side in the figure where the hole 57A is located. According to the above configuration, the connecting shaft 255 connected to the portion of the spool 50 having the hole 57A is eccentric toward the side where the hole 57A is located, thereby increasing the rigidity of the side where the hole 57A is located. Since the presence of the hole 57A reduces the rigidity of the side where the hole 57A is located, the rigidity can be increased by eccentricity of the connecting shaft 255, thereby reducing the difference in rigidity between each position.

[0062] In the above embodiment, the deformation suppression portion is provided in the center of the spool 50 in the axial direction. However, the deformation suppression portion may be provided in a position other than the center of the spool 50 in the axial direction. In the above embodiment, the deformation suppression portion is provided in the center of the sleeve 40 in the axial direction. However, the deformation suppression portion may be provided in a position other than the center of the sleeve 40 in the axial direction.

[0063] In the above embodiment, the sleeve 40 and the spool 50 are provided with a deformation suppressing portion, but the deformation suppressing portion may be provided only on either the sleeve 40 or the spool 50 .

[0064] In the above embodiment, the tank 6 may be connected to the hole 47A. The servo valve of the above embodiment may be applied to a control valve used in a flight control actuator.

[0065] In the above embodiment, if a product is made up of multiple objects, the multiple objects may be integrated, and conversely, if a product is made up of one object, it may be divided into multiple objects. Regardless of whether the objects are integrated or not, it is sufficient that the product is configured to achieve the object of the invention. [Explanation of symbols]

[0066] 1 Fluid device 2 Servo valve 3. First Pump 4 Spool Valve 5A Second Pump 5B 3rd pump 6. Tank 10 Nozzles 11 Inlet 12 Outlet 20 Receiver 21 Left inlet 22 Right inlet 23 Left channel 24 Right channel 25 Left outlet 26 Right outlet 30 Torque motor 31 Left coil 32 Right coil 33 Upper pole piece 34 Lower pole piece 35 Magnetic Rod 40 Sleeve 41 First Chamber 42 Second Chamber 43 Third Chamber 44 Fourth Chamber 45 5th Chamber 46 Central part 47 Hole forming part 47A hole 48 Groove (deformation suppression part) 50 spools 51 1st bulkhead 52 2nd bulkhead 53 Third bulkhead 54 4th bulkhead 55 Connecting shaft 56 Central part 57 Hole forming part 57A hole 58 Concave portion (deformation suppression portion) 60 Cantilever Spring 61 Port 1 62 Second Port 63 Third Port 64 4th Port 65 5th Port 66 6th Port 67 7th Port 70 Actuator 71 Case 72 Movable piece 72A Bulkhead 72B Rod 73 Left port 74 Right Port 75 Left Chamber 76 Right Chamber

Claims

1. A cylindrical sleeve; a cylindrical spool located inside the sleeve and configured to open a fluid supply path by moving from a closed position; a spring coupled to the spool to cause the spool to remain in the closed position; The sleeve is a hole forming portion having a hole through which the spring passes; a deformation suppressing portion provided on at least one of the side where the hole is located and the side opposite to the side where the hole is located, the deformation suppressing portion suppressing a displacement of the center axis of the sleeve with respect to the center axis of the spool when the sleeve is deformed to be less than a gap between the sleeve and the spool. Servo valve.

2. The deformation suppression portion is provided at the center of the sleeve in the axial direction.

2. The servo valve of claim 1.

3. The deformation suppression portion includes a groove provided on the side where the hole is located.

3. The servo valve according to claim 2.

4. The deformation suppression portion includes a reinforcing portion provided on the side opposite to the side on which the hole is located.

4. A servo valve according to claim 2 or 3.

5. A cylindrical sleeve; a cylindrical spool located inside the sleeve; a spring coupled to the spool to cause the spool to remain in a closed position; The spool is a hole forming portion having a hole for connecting the spring; a deformation suppressing portion provided on at least one of the side opposite to the side where the hole is located and the side where the hole is located, and configured to suppress the displacement of the central axis of the spool relative to the central axis of the sleeve when the spool is deformed to be less than the gap between the sleeve and the spool. Servo valve.

6. The deformation suppression portion is provided at the center of the spool in the axial direction.

6. The servo valve according to claim 5.

7. The deformation suppression portion includes a recess provided on the side opposite to the side on which the hole is located.

7. The servo valve according to claim 6.

8. The deformation suppression portion includes a reinforcing portion provided on the side where the hole is located.

8. A servo valve according to claim 6 or 7.

9. The deformation suppressing portion causes a central axis of a shaft connected to a portion having the hole to be offset toward the side having the hole.

8. A servo valve according to claim 6 or 7.

10. A cylindrical sleeve; a cylindrical spool located inside the sleeve and configured to open a fluid supply path by moving from a closed position; a spring coupled to the spool to cause the spool to remain in the closed position; The sleeve is a first hole forming portion having a first hole through which the spring passes; a first deformation suppressing portion provided on at least one of the side where the hole is located and the side opposite to the side where the hole is located, the first deformation suppressing portion suppressing a displacement of the center axis of the sleeve with respect to the center axis of the spool when the sleeve is deformed to be less than a gap between the sleeve and the spool; The spool is a second hole forming portion having a second hole for connecting the spring; a second deformation suppressing portion provided on at least one of the side opposite to the side where the hole is located and the side where the hole is located, and configured to suppress displacement of the central axis of the spool relative to the central axis of the sleeve when the spool is deformed to be less than the gap between the sleeve and the spool. Servo valve.

11. a servo valve including a cylindrical sleeve, a cylindrical spool located inside the sleeve and configured to open a fluid supply path by moving from a closed position, and a spring connected to the spool to hold the spool in the closed position; an actuator that is driven by a fluid supplied by moving the spool inside the sleeve; The sleeve is a hole forming portion having a hole through which the spring passes; a deformation suppressing portion provided on at least one of the side where the hole is located and the side opposite to the side where the hole is located, and configured to suppress the displacement of the center axis of the sleeve with respect to the center axis of the spool when the sleeve is deformed to be less than the gap between the sleeve and the spool. Fluid equipment.

12. a servo valve including a cylindrical sleeve, a cylindrical spool located inside the sleeve, and a spring coupled to the spool to maintain the spool in a closed position; an actuator that is driven by a fluid supplied by moving the spool inside the sleeve; The spool is a hole forming portion having a hole for connecting the spring; a deformation suppressing portion provided on at least one of the side opposite to the side where the hole is located and the side where the hole is located, and configured to suppress the displacement of the central axis of the spool relative to the central axis of the sleeve when the spool is deformed to be less than the gap between the sleeve and the spool. Fluid equipment.

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