Fastening devices, fluid control devices

Abstract

To provide a fastener which can alleviate a concentration of stress to a screw part.SOLUTION: A fastener 4B of a hydraulic port being a fastener 4B for fastening a union 6 in which a male screw 51 is formed, and a female member 5 in which a female screw 51 is formed, comprises an escape part 52 which is arranged while adjoining a terminal end part of the female screw 51 at a side opposite to a side to which the male screw 61 is inserted, and whose inside diameter is larger than an outside diameter of the male screw 61 in the female member 5. The escape part 52 comprises a cutup part 521 which is linearly cut up while forming an angle of 90° or smaller with respect to an insertion direction of the male screw 61 from the terminal end part 51E of the female screw 51. A tip part 61E of the male screw 61 fastened to the female screw 61 protrudes with respect to the terminal end part 51E of the female screw 51.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention Fastening devices and This relates to a fluid control device. [Background technology]

[0002] An aircraft or construction machine driven by hydraulic pressure generated by a hydraulic control device, which is an example of a fluid control device, is equipped with a complex hydraulic circuit for flowing hydraulic oil to each part. The hydraulic circuit includes a manifold to which hydraulic control elements such as numerous pipes and valves through which the hydraulic oil flows are connected, and hydraulic actuators such as cylinders that convert the pressure of the hydraulic oil flowing from the manifold into mechanical power. Such hydraulic circuits include connections between pipes, connections between pipes or hydraulic control elements and the manifold, and numerous fastening parts (hereinafter collectively referred to as hydraulic ports), such as caps for oil inlets that supply hydraulic oil to the manifold and oil drain ports that discharge the hydraulic oil, and require secure fastening to prevent leakage of the hydraulic oil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2021 / 0018020 [Patent Document 2] JP 2020-34022 A Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses a fluid control device for a hydraulic port in an aircraft hydraulic drive system, which uses male and female threads that fasten together. Aircraft typically experience repeated pressure fluctuations of about 0-5000 psi (pounds per square inch), and the resulting stress is concentrated in the threads, which can cause cracks and lead to leakage of hydraulic oil.

[0005] The present invention has been made in view of the above circumstances, and its object is to provide a method for reducing the concentration of stress on a threaded portion. conclusion The present invention aims to provide an apparatus for [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides conclusion The device fastens a male member having an external thread to a female member having an internal thread. conclusion The device includes a relief portion that is provided adjacent to an end portion of the female thread on the side opposite to the side where the male thread is inserted in the female member and has an inner diameter larger than the outer diameter of the male thread. According to this aspect, the relief portion that is larger in diameter than the male thread can reduce stress concentration on the threaded portion.

[0007] Another aspect of the invention teeth This device is a fastening device for fastening a male member having a male thread and a female member having a female thread, and includes a recess provided adjacent to an end of the female thread on the side of the female member opposite to the side where the male thread is inserted and having an inner diameter larger than the outer diameter of the male thread, and a fluid control unit for controlling the flow of fluid passing through the space inside the recess.

[0008] Any combination of the above components, and any transformation of the present invention into a method, device, system, recording medium, computer program, etc., are also effective as aspects of the present invention. Effect of the Invention

[0009] According to the present invention, the concentration of stress on the threaded portion can be reduced. [Brief description of the drawings]

[0010] [Figure 1] 1 shows a schematic of an aircraft hydraulic system. [Diagram 2] 1 shows a fluid control device for a hydraulic port. [Diagram 3] Dimensions of each part of the fluid control device are shown diagrammatically. [Figure 4]3A and 3B are schematic diagrams illustrating stresses applied to a female member of a fluid control device. [Diagram 5] 4 shows another configuration example of the fluid control device. [Figure 6] 13 shows yet another configuration example of the fluid control device. [Figure 7] 1 shows a schematic configuration of a construction machine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention conclusion The device is useful for fastening hydraulic ports in any hydraulic device. Therefore, although the application field and the applicable product are not limited, the present invention can be applied to hydraulic devices provided in products such as reduction gears, construction machines, aircraft, railway vehicles, ships, automobiles, automatic doors, packaging machines, prosthetic limbs, wheelchairs, and three-dimensional modeling devices. In this embodiment, an example in which the present invention is applied to an aircraft will be described.

[0012] 1 shows a schematic diagram of a hydraulic system 1 of an aircraft (not shown) equipped with a moving surface 100. The moving surface 100 is a control surface, and constitutes, for example, ailerons (auxiliary wings) provided on the main wing, elevators (elevators) provided on the horizontal stabilizer, and rudder (rudder) provided on the vertical stabilizer. The moving surface 100 may be constituted by spoilers such as flight spoilers and ground spoilers, or flaps, etc.

[0013] The hydraulic actuator 13 includes a cylinder 15 and a rod 16 provided with a piston 16a. The inside of the cylinder 15 is divided into two oil chambers that do not communicate with each other by the piston 16a. Each oil chamber of the hydraulic actuator 13 can be communicated with an aircraft central hydraulic power source 102 and a reservoir circuit 104 via a control valve 17 serving as a fluid control unit.

[0014] The aircraft-side hydraulic power source 102 is a hydraulic pump that supplies pressure oil and is installed inside the aircraft (not shown). The pressure oil supplied from the aircraft-side hydraulic power source 102 drives the hydraulic actuator 13 of the rotor blade 100 and other actuators (not shown) of the aircraft.

[0015] The control valve 17 constitutes a valve mechanism that switches the connection state between a supply passage 102a communicating with the aircraft central hydraulic power source 102 and a discharge passage 104a communicating with the reservoir circuit 104, and each oil chamber of the hydraulic actuator 13. The control valve 17 is configured as, for example, an electromagnetic switching valve, and is driven based on a command from an actuator controller 11 that controls the operation of the hydraulic actuator 13.

[0016] The actuator controller 11a controls the hydraulic actuator 13a based on commands from the flight controller 3, which serves as a higher-level computer that controls the operation of the rotor blade 100. The actuator controller 11 controls the hydraulic actuator 13 based on commands from the flight controller 3, which serves as a higher-level computer that controls the operation of the rotor blade 100.

[0017] The control valve 17 switches between the oil chamber of the hydraulic actuator 13 communicated with the supply passage 102a and the oil chamber of the hydraulic actuator 13 communicated with the discharge passage 104a based on a command from the actuator controller 11. Pressurized oil is supplied to one of the oil chambers of the hydraulic actuator 13 communicated with the supply passage 102a, and oil is discharged from the other oil chamber of the hydraulic actuator 13 communicated with the discharge passage 104a. As oil flows in and out of each oil chamber of the hydraulic actuator 13, the rod 16 equipped with the piston 16a is displaced relative to the cylinder 15 to drive the rotor blade 100.

[0018] The flight controller 3 is a computer that controls the operation of the rotor blade 100, and is a controller that transmits various control signals to the actuator controller 11. The flight controller 3 includes a CPU (Central Processing Unit), a memory, an interface, and the like (not shown).

[0019] Various hydraulic devices that make up the hydraulic system 1 as described above, such as the hydraulic actuator 13, the control valve 17, and part or all of various pipes 102a, 104a that connect these hydraulic devices to each other, are interconnected in one or more manifolds arranged inside the fixed wing where the moving wing 100 is provided to form a complex hydraulic circuit. In such a hydraulic circuit or manifold, there are a number of fastening parts (hereinafter collectively referred to as hydraulic ports) such as the connection parts between hydraulic circuit elements, the oil supply port to which the hydraulic oil from the aircraft-side hydraulic source 102 outside the manifold is supplied, the oil discharge port that discharges the hydraulic oil to the reservoir circuit 104 outside the manifold, and the cap that seals the opening on the manifold surface to prevent leakage of the hydraulic oil. A reliable fastening is required to prevent the hydraulic oil from leaking. A fluid control device 4 that constitutes a fastening device described below is provided at such a hydraulic port. Fig. 1 schematically shows the locations of the hydraulic ports where the fluid control device 4 can be installed.

[0020] Fig. 2 shows the fluid control device 4 provided at the hydraulic port. Fig. 2(A) shows a conventional typical fluid control device 4A, and Fig. 2(B) shows the fluid control device 4B of the present embodiment. The fluid control devices 4A, 4B at the hydraulic port are composed of a female member 5 formed integrally with the manifold and a union 6 as a male member fastened to the female member 5 by a screw. A female thread 51 is formed in the female member 5 along the insertion direction of the union 6 (the vertical direction in Fig. 2), and a male thread 61 is formed in the union 6 along the insertion direction of the union 6, that is, the formation direction of the female thread 51. By tightening while the male thread 61 is inserted into the female thread 51, the union 6 is fastened to the manifold (female member 5).

[0021] The union 6 is provided with a fastening portion 62 having an outer diameter larger than that of the male thread 61, adjacent to the end (upper end in FIG. 2) of the male thread 61 on the side opposite to the side inserted into the female thread 51. When the male thread 61 is inserted into the female thread 51 to the maximum insertion amount and the tip (lower end in FIG. 2) of the male thread 61 reaches the insertion end 61E, the fastening portion 62 comes into contact with the female member 5 or the surface of the manifold, thereby fastening the union 6 to the female member 5. A packing 63 such as an O-ring is provided between the fastening portion 62 and the surface of the female member 5 to prevent leakage of hydraulic oil in the manifold.

[0022] Another male thread 64 is formed on the opposite side of the fastening portion 62 from the male thread 61 that engages with the female thread 51 (upper side in FIG. 2). A pipe or hydraulic device having a female thread (not shown) that engages with the male thread 64 can be attached to the male thread 64. For example, if a pipe constituting a supply passage 102a that communicates with the aircraft-side hydraulic source 102 in FIG. 1 is attached to the male thread 64, hydraulic oil from the aircraft-side hydraulic source 102 is supplied into the manifold through the union 6. A flow path 65 that communicates between both ends (upper and lower ends in FIG. 2) is provided inside the union 6, so that hydraulic oil can flow between the upper side where the male thread 64 is formed and the lower side where the male thread 61 is formed. The outer diameters of the male threads 61 and 64 may be the same as shown in the figure, or may be different.

[0023] The female member 5 has a recess 52 adjacent to the end 51E of the female thread 51 on the side opposite to the side where the male thread 61 is inserted (the lower side in FIG. 2). The recess 52 does not have a female thread that engages with the male thread 61. Inside the recess 52, a hydraulic oil space 53 through which hydraulic oil flows is formed. The hydraulic oil space 53 communicates with a flow path 54 through which hydraulic oil can flow between other parts in the manifold on the side opposite to the side where the male thread 61 is inserted (the lower side in FIG. 2). When the male member is configured as the illustrated union 6, hydraulic oil flowing through the flow path 65 and the flow path 54 between the inside of the manifold and an external piping or hydraulic device attached to the male thread 64 flows in the hydraulic oil space 53. When the male member is configured as a cap that seals the opening (female member 5) of the manifold surface, hydraulic oil inside the manifold that flows through the flow path 54 flows or stagnates in the hydraulic oil space 53.

[0024] Next, differences between a typical conventional fluid control device 4A shown in Fig. 2(A) and a fluid control device 4B of this embodiment shown in Fig. 2(B) will be described. These differences are applied to this embodiment for the purpose of reducing the concentration of stress on the threaded portion, as will be described later.

[0025] The first difference between the fluid control device 4A and the fluid control device 4B is the inner diameter (the length in the left-right direction in FIG. 2) of the relief portion 52. In the fluid control device 4A, the inner diameter of the relief portion 52 is approximately equal to the outer diameter of the male thread 61, but in the fluid control device 4B, the inner diameter of the relief portion 52 is larger than the outer diameter of the male thread 61. Specifically, the inner diameter of the relief portion 52 in the fluid control device 4B is 1.03 times or more the outer diameter of the male thread 61. The inner diameter of the relief portion 52 is also the inner diameter of the hydraulic oil space 53.

[0026] FIG. 3 shows the dimensions of each part of the fluid control device 4B. The outer diameter B of the male thread 61 is the diameter of a cylinder formed by connecting the crests of each thread of the male thread 61, and is approximately equal to the diameter of a cylinder formed by connecting the bottoms of each thread valley of the inner diameter of the female thread 51. The outer diameter B of the male thread 61 is typically between 10 mm and 51 mm. The inner diameter of the relief portion 52 is represented by C, which satisfies the relational expression C≧1.03×B as described above. Specifically, the inner diameter C of the relief portion 52 is determined from the outer diameter B of the male thread 61 by the relational expression C=1.03×B+2.05 (mm) that the present inventor discovered from the viewpoint of stress concentration relaxation.

[0027] E is the height of the relief portion 52 (length in the vertical direction in FIG. 3), and is preferably 3 mm or more from the viewpoint of stress concentration relaxation. Rt is the radius of the arc portion provided at the corner of the relief portion 52, and is preferably 0.04 times or more the outer diameter B of the male thread 61 (Rt≧0.04×B). Specifically, the radius Rt is determined from the outer diameter B of the male thread 61 by the relational expression Rt=0.04×B+0.542 (mm) that the present inventor found from the viewpoint of stress concentration relaxation. It is preferable that the arc portion of radius Rt is provided at all four corners of the relief portion 52 shown in the figure. A is the outer diameter of the female member 5, and is preferably 1.25 times or more the outer diameter B of the male thread 61 (A≧1.25×B). Specifically, the outer diameter A of the female member 5 is determined from the outer diameter B of the male thread 61 by the relational expression A=1.25×B+6.70 (mm) that the present inventor found from the viewpoint of stress concentration relaxation.

[0028] Although not shown, the radius R of the arc portion provided at the bottom of each thread valley of the female thread 51 also has the effect of relieving stress concentration, and is preferably set to 0.00449 times or more the outer diameter B of the male thread 61 (R≧0.00449×B). Specifically, the radius R is determined from the outer diameter B of the male thread 61 by the relational expression R=0.00449×B+0.0863 (mm), which the present inventors discovered from the viewpoint of relieving stress concentration.

[0029] Returning to FIG. 2, the second difference between the fluid control device 4A and the fluid control device 4B is the presence or absence of a cut portion in the relief portion 52. In the fluid control device 4A, the relief portion 52 is hardly cut up from the terminal portion 51E of the female thread 51, so no cut portion is formed, whereas in the fluid control device 4B, a cut portion 521 is formed in which the relief portion 52 is cut up linearly from the terminal portion 51E of the female thread 51. As will be described later, from the viewpoint of stress concentration relief, it is preferable that the angle θ at which the cut portion 521 is cut up from the terminal portion 51E of the female thread 51 is 90 degrees or less with respect to the insertion direction of the male thread 61 (the direction from top to bottom in FIG. 2). As shown in the figure, if the angle θ at which the cut portion 521 is cut up from the terminal portion 51E of the female thread 51 is 90 degrees with respect to the insertion direction of the male thread 61, the effect of stress concentration relief can be maximized.

[0030] A third difference between the fluid control device 4A and the fluid control device 4B is the position of the insertion end 61E of the male thread 61 relative to the terminal end 51E of the female thread 51. In the fluid control device 4A, the insertion end 61E of the male thread 61 is located in front of the terminal end 51E of the female thread 51 (upper part in FIG. 2), whereas in the fluid control device 4B, the insertion end 61E of the male thread 61 is located behind the terminal end 51E of the female thread 51 (lower part in FIG. 2). As a result, in the fluid control device 4B, the insertion end 61E as the tip part of the male thread 61 fastened to the female thread 51 is inserted inside the hydraulic oil space 53.

[0031] FIG. 4 shows a schematic diagram of stress applied to the vicinity of the region where the threads of the female member 5 and the male member 6 of the fluid control device 4A and 4B are fitted together. FIG. 4(A) shows the fluid control device 4A, and FIG. 4(B) shows the fluid control device 4B. The stress lines S shown on the female member 5 and the male member 6 indicate that the higher the density, the stronger the stress applied. In FIG. 4(A), hydraulic pressure P is applied to the insertion end 61E of the male thread 61, which is located in a position recessed from the terminal end 51E of the female thread 51, and stress is concentrated on the first complete thread 511 of the female thread 51 counting from there. In this state where excessive stress is concentrated on the first thread 511, if pressure fluctuations of about 0-5000 psi, which are typical of aircraft, are repeated, there is a risk that cracks will occur from the thread 511, whose strength has been reduced by fatigue, causing leakage of hydraulic oil.

[0032] In contrast, in FIG. 4(B), the concentration of stress on the first thread 511 of the female thread 51 is alleviated by the various features of the fluid control device 4B described above with reference to FIG. 2(B) and FIG. 3. Regarding the inner diameter of the relief portion 52, which is listed as the first difference between the fluid control device 4A and the fluid control device 4B, in FIG. 4(B), the inner diameter of the relief portion 52 is made larger than the outer diameter of the male thread 61 or the inner diameter of the female thread 51, so that the stress line S extending from below on the side of the relief portion 52 (left side of FIG. 4) is less likely to reach the first thread 511 of the female thread 51. That is, by increasing the inner diameter of the relief portion 52, the hydraulic pressure receiving area in the relief portion 52 is increased, so that the hydraulic pressure P per unit area is reduced and the stress acting on the first thread 511 is reduced, which is considered to make it difficult for the stress line S to reach the first thread 511. For this reason, the concentration of stress on the first thread 511 as shown in FIG. 4(A) can be alleviated.

[0033] Regarding the cut portion 521 in the relief portion 52, which is listed as the second difference between the fluid control device 4A and the fluid control device 4B, in Fig. 4(B), the cut portion 521 is cut up steeply at a right angle from the terminal end 51E of the female thread 51, so that the stress line S extending from below on the side of the relief portion 52 (left side in Fig. 4) is less likely to reach the first thread 511 of the female thread 51. In other words, the cut portion 521 is cut up steeply, so that the hydraulic pressure receiving area in the relief portion 52 is increased, and the stress line S is dispersed by the deformation of the relief portion 52, so that it is less likely to reach the first thread 511. For this reason, it is possible to alleviate the concentration of stress in the first thread 511 as shown in Fig. 4(A).

[0034] Regarding the position of the insertion end 61E of the male thread 61 relative to the terminal end 51E of the female thread 51, which is the third difference between the fluid control device 4A and the fluid control device 4B, in FIG. 4(A) where the insertion end 61E of the male thread 61 is recessed from the terminal end 51E of the female thread 51, the hydraulic pressure P applied to the insertion end 61E of the male thread 61 directly becomes stress on the female thread 51, and stress concentration occurs especially on the first thread 511. In contrast, in FIG. 4(B) where the insertion end 61E of the male thread 61 protrudes from the terminal end 51E of the female thread 51, the hydraulic pressure is received not only by the insertion end 61 of the male thread 61 but also by the surrounding relief portion 52 (cut portion 521), so that the stress line S is dispersed by the deformation of the relief portion 52, making it difficult for the stress line S to reach the first thread 511. Therefore, in the fluid control device 4B, the stress on the thread 511 due to the hydraulic pressure P can be reduced. 4(B), if the insertion end 61E of the male thread 61 protrudes too far from the terminal end 51E of the female thread 51, the pressure applied to the side surface of the protruding male thread 61 may become stress applied to the female thread 51. In this case, if the positions of the terminal end 51E of the female thread 51 and the insertion end 61E of the male thread 61 are aligned to fully engage the female thread 51 and the male thread 61, the pressure applied to the side surface of the male thread 61 can be minimized.

[0035] In addition to the above differences, in the fluid control device 4B, the corners of the relief portion 52 are formed as arcs with a radius Rt, which can alleviate the concentration of stress there. Also, the bottoms of the thread roots of the female thread 51 are formed as arcs with a radius R, which can alleviate the concentration of stress there.

[0036] As described above, the concentration of stress on the female thread 51 is alleviated by various features of the fluid control device 4B of this embodiment. It is preferable to adopt all of the above features in order to maximize the effect of stress concentration alleviation, but adopting at least one feature will provide an advantageous effect over the conventional fluid control device 4A. In addition, with reference to FIG. 3, suitable relational expressions for obtaining the effect of stress concentration alleviation are shown for the inner diameter C of the relief portion 52, the height E of the relief portion 52, the radius Rt of the arc portion at the corner of the relief portion 52, the outer diameter A of the female member 5, and the radius R of the arc portion at the bottom of each thread valley of the female thread 51. These relational expressions are standards for designing the fluid control device 4B, but are not absolute standards because adjustments must be made in consideration of various errors such as product specifications and manufacturing tolerances when determining the final product dimensions.

[0037] Next, other configuration examples of the fluid control device 4B of this embodiment are shown in Figures 5(A) to (D). In these figures, only the female member 5 is shown, and male members such as the union 6 are omitted. In Figure 5(A), the cut-up portion 521, which is cut up at an angle of 90 degrees with respect to the insertion direction of the male thread 61 in Figure 2(B), is cut up at an acute angle of less than 90 degrees. With this configuration, the cut-up portion 521 can be easily processed compared to Figure 2(B) with a steep cut-up angle. In Figure 5(B), the side surface of the relief portion 52 is formed in an arc shape. In this case, the arc-shaped side surface of the relief portion 52 forms the cut-up portion 521 that is cut up in an arc shape from the terminal portion 51E of the female thread 51. With this configuration, since there is no straight portion on the side surface of the relief portion 52, the longitudinal dimension (the vertical direction in Figure 5) can be made smaller than that of the fluid control device 4B of Figure 3 in which a straight portion exists between two arc portions of radius Rt.

[0038] In Fig. 5(C) and Fig. 5(D), the female member 5 is provided with hydraulic oil ports 54, 55 as a plurality of fluid ports through which hydraulic oil can flow between the female member 5 and the hydraulic oil space 53. The flow direction of the hydraulic oil in the second hydraulic oil port 55 may cross the flow direction of the hydraulic oil in the first hydraulic oil port 54 as in Fig. 5(C), or may be parallel to the flow direction of the hydraulic oil in the first hydraulic oil port 54 as in Fig. 5(D). In Fig. 5(C), the height (vertical length in Fig. 5) of the relief portion 52 can be increased by providing the second hydraulic oil port 55, and in Fig. 5(D), the inner diameter (horizontal length in Fig. 5) of the relief portion 52 can be increased by providing the second hydraulic oil port 55, and the concentration of stress on the female thread 51 can be alleviated. In Figs. 2 to 5, the relief portion 52 in the fluid control device 4B may be provided midway along the female thread 51.

[0039] Further configuration examples of the fluid control device 4B of this embodiment are shown in Figures 6(A) to (G). These are modified examples of Figure 5(D), and the cross-sectional shape of the relief portion 52 and the arrangement of the hydraulic oil port 55 are different. In Figure 6(A), the cross-sectional shape of the relief portion 52 is approximately triangular, in Figure 6(B), the cross-sectional shape of the relief portion 52 is approximately trapezoidal, in Figure 6(C), the cross-sectional shape of the relief portion 52 is approximately hexagonal, in Figure 6(D), the cross-sectional shape of the relief portion 52 is approximately sector-shaped with a central angle larger than 180 degrees, in Figure 6(E), the cross-sectional shape of the relief portion 52 is approximately circular cut by a straight line, and in Figure 6(F), the cross-sectional shape of the relief portion 52 is approximately star-shaped (approximately dodecagonal). Also, in Figure 6(G), the cross-sectional shape of the relief portion 52 is approximately annular cut by a straight line, and two hydraulic oil ports 55 are provided at both ends. The female member 5 having the relief portions 52 of various shapes can be manufactured by, for example, three-dimensional modeling using a 3D printer or casting. The cross-sectional shape of the relief portions 52 and the arrangement of the hydraulic oil ports 55 may be asymmetric, and the corners included in the cross-sectional shape of the relief portions 52 may be arcuate to reduce stress concentration.

[0040] The present invention has been described above based on the embodiments. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each treatment process, and that such modifications are also within the scope of the present invention.

[0041] In the embodiment, the fluid control device 4B is applied to an aircraft, but the fluid control device 4B may be applied to other products, such as a construction machine. FIG. 7 shows a schematic configuration of a construction machine 200. In the construction machine 200, an upper rotating body 202 is rotatably attached on a lower traveling body 201 that can travel on the ground. A cab 203 is provided on the front left side of the upper rotating body 202, and a boom 204 is attached to the front center part so as to be able to rise and fall. An arm 205 is attached to the tip of the boom 204 so as to be bent up and down. A bucket 206 is attached to the tip of the arm 205 so as to be bent up and down. The hydraulic system 1 of the construction machine 200 drives each movable part such as the lower traveling body 201, the upper rotating body 202, the boom 204, the arm 205, and the bucket 206 by the hydraulic pressure of the hydraulic oil. The hydraulic system 1 of the construction machine 200 is provided with a hydraulic device having a large number of hydraulic ports, such as the hydraulic control valve block shown in Patent Document 2, and the fluid control device 4B of this embodiment can be used to fasten these hydraulic ports.

[0042] Among the embodiments disclosed in this specification, those in which multiple functions are provided in a distributed manner may have some or all of the multiple functions integrated together, and conversely, those in which multiple functions are provided in a distributed manner may have some or all of the multiple functions integrated together. Regardless of whether the functions are integrated or distributed, it is sufficient that the configuration is such that the object of the invention can be achieved. [Explanation of symbols]

[0043] 1 hydraulic system, 4B fluid control device (fastening device), 5 female member, 6 union (male member), 13 hydraulic actuator, 17 control valve (fluid control section), 51 female thread, 51E terminal end, 52 relief portion, 53 hydraulic oil space, 54, 55 hydraulic oil port (fluid port), 61 male thread, 61E insertion end (tip portion), 100 rotor, 200 construction machine, 201 lower running body (movable part), 202 upper rotating body (movable part), 204 boom (movable part), 205 arm (movable part), 206 bucket (movable part), 511 thread, 521 cutting upper part.

Claims

1. A fastening device for fastening a male member having a male thread and a female member having a female thread, The female member has a recess portion provided adjacent to a terminal end of the female thread on a side opposite to a side into which the male thread is inserted, the recess portion having an inner diameter larger than an outer diameter of the male thread, The female member includes a plurality of fluid ports through which fluid can flow between the female member and the recessed portion having a space through which fluid can flow. Fastening device.

2. The fastening device according to claim 1 , wherein the recess comprises a cut-out portion that is cut up linearly from a terminal end of the female thread at an angle of 90 degrees or less with respect to an insertion direction of the male thread.

3. The fastening device according to claim 1 , wherein the recessed portion includes a cut-out portion that is cut up in an arc shape from a terminal end portion of the female thread.

4. The fastening device according to claim 1 , wherein a tip portion of the male screw fastened to the female screw protrudes beyond a terminal end portion of the female screw.

5. The fastening device according to claim 1 , wherein an inner diameter of the recess is 1.03 times or more the outer diameter of the male thread.

6. a fastening device for fastening a male member having a male thread and a female member having a female thread, the fastening device comprising a recess provided adjacent to a terminal end of the female thread on a side opposite to a side into which the male thread is inserted, the recess having an inner diameter larger than an outer diameter of the male thread, the female member comprising a plurality of fluid ports through which a fluid can flow between the recess and the female member, the recess having a space through which a fluid can flow; a fluid control unit for controlling a flow of a fluid passing through a space inside the recess; A fluid control device comprising:

7. The fluid control device according to claim 6, wherein a moving surface of an aircraft is driven by the pressure of the fluid generated by the fluid control unit.

8. The fluid control device according to claim 6, wherein a moving part of a construction machine is driven by the pressure of the fluid generated by the fluid control unit.

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