Coupling Device

Abstract

To provide a compact coupling device.SOLUTION: A coupling device of the invention has a first joint (3) and a second joint (4). In the second joint 4, a sub valve chamber (27) and a main valve chamber (28) are formed so as to be continuous in the vertical direction. A sub valve member (33) is inserted into the sub valve chamber (27) so as to be movable in the vertical direction in a sealed manner. The sub valve member (33) is biased downward by a valve-closing spring (40) against a sub valve seat (32) formed inside the sub valve chamber (27). A communication path (35) is formed in the sub valve member (33). The communication path (35) forms a part of a flow passage that causes the sub valve chamber (27) and the main valve chamber (28) to communicate with each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a coupling device that separably connects supply and discharge passages formed in a first joint and a second joint. [Background technology]

[0002] Conventional couplers of this type are described in Patent Document 1 (Japanese Patent Laid-Open Publication No. 60-67042) and Patent Document 2 (Japanese Patent Laid-Open Publication No. 2003-117748). These conventional techniques are configured as follows.

[0003] The coupling in Patent Document 1 has a male plug and a female plug. An inlet / outlet valve and a main valve are provided in series within a plug case of the female plug. A flow path that connects the valve chambers of the inlet / outlet valves with the valve chamber of the main valve is provided within the plug case, radially outside the valve chambers. A ring-shaped protective filter is attached to an annular space formed midway through the flow path.

[0004] The quick disconnect coupling of Patent Document 2 has a plug as a first coupling and a socket as a second coupling. A second flow path and a check valve chamber are arranged in series within the housing of the plug, with a second closing member inserted into the second flow path and a check member inserted into the check valve chamber. A flow path connecting the second flow path and the check valve chamber is formed within the housing, radially outward of the second closing member. A cylindrical filter is attached to the flow path. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 60-67042 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-117748 Summary of the Invention [Problem to be solved by the invention]

[0006] In the female plug of the coupling in Patent Document 1, a flow path connecting the valve chamber of the main valve and the valve chamber of the inlet / outlet valve is formed outside the valve chamber, and a filter is attached midway along the flow path, so the radial dimension of the female plug is larger by the distance of the flow path and the filter.

[0007] In addition, in the plug of the quick disconnect coupling in Patent Document 2, a flow path that connects the second flow path and the check valve chamber is formed radially outside the second closing member, and a cylindrical filter is attached midway along the flow path, so the radial dimension of the plug is larger by the distance of the flow path and the filter.

[0008] The diameter of the coupling devices (couplings, quick disconnect couplings, etc.) in Patent Documents 1 and 2 is generally small, for example, about 20 mm. There is a demand for maintaining or increasing the flow rate of fluid that can flow through such small coupling devices, while also making the overall dimensions more compact than conventional coupling devices.

[0009] SUMMARY OF THE INVENTION An object of the present invention is to provide a compact coupling device. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention provides a coupling device configured as follows, as shown in, for example, FIGS. 1 to 3 and 4 to 6. The coupling device has a first joint 3 and a second joint 4 detachably connected to the first joint 3. A first supply / discharge passage 5 is provided in the first joint 3. A second supply / discharge passage 6 detachably connected to the first supply / discharge passage 5 is provided in the second joint 4. A sub-valve chamber 27 and a main valve chamber 28 are formed in the second joint 4 so as to be continuous from the tip end to the base end in the axial direction. A sub-valve member 33 is axially movable and hermetically inserted into the sub-valve chamber 27 via a sealing member 34. The sub-valve member 33 is urged by a second valve-closing spring 40 toward the tip end toward a sub-valve seat 32 formed in the sub-valve chamber 27. The sub-valve member 33 has a sub-valve surface 41 that can abut against the sub-valve seat 32. A main valve member 43 is axially movable and hermetically inserted into the main valve chamber 28. The main valve member 43 can abut against the sub-valve member 33. Further, the main valve member 43 is biased by a valve-closing spring 48 toward the tip side toward the main valve seat 42 formed in the main valve chamber 28. A communication passage 35 as part of the second supply / discharge passage 6 is formed in the sub-valve member 33.

[0011] The present invention as described above has the following advantages. In the coupling device of the present invention, a communication passage as part of the second supply / discharge passage is formed within the sub-valve member, which allows the coupling device of the present invention to be made more compact than the conventional coupling device described above in which the communication passage connecting the sub-valve chamber and the main valve chamber is formed outside the valve chamber.

[0012] The present invention preferably includes the following features (1) to (3). (1) For example, as shown in Figures 1 to 3 and 4 to 6, one end of the communication passage 35 opens on the outer peripheral surface of the sub-valve member 33, between a portion sealed by the sealing member 34 and the sub-valve surface 41. The other end of the communication passage 35 is between the sub-valve member 33 and the main valve member 43, and communicates with the sub-valve chamber 27. In this case, a communicating passage is formed in the sub-valve member inserted into the sub-valve chamber. In other words, the communicating passage is formed to fit within the sub-valve chamber. Furthermore, the two spaces communicated by the communicating passage (a space partitioned by the inner circumferential surface of the sub-valve chamber and the outer circumferential surface of the sub-valve member, and sealed by the sealing member, the sub-valve face, and the sub-valve seat, and a space formed between the sub-valve member and the main valve member by the communicating passage) are also provided to fit within the sub-valve chamber. Therefore, the coupling device of the present invention can be made more compact than the conventional coupling device described above, in which the communicating passage is formed outside the valve chamber.

[0013] (2) A filter 38 is attached to the middle of the communication passage 35 . In this case, the communication passage and filter can be housed inside the sub-valve member inserted into the sub-valve chamber, which allows the coupling device of the present invention to be made more compact than conventional coupling devices in which the communication passage and filter are provided outside the valve chamber.

[0014] (3) A support member 36 protruding from the wall surface of the communication passage 35 supports a disk-shaped filter 38. The sub-valve member 33 can abut against the main valve member 43 via the support member 36 and the filter 38. In this case, the portion of the disk-shaped filter that supports the filter, such as the portion that abuts against the support member (hereinafter referred to as the supported portion), does not function to remove foreign matter. Therefore, minimizing the portion that supports the filter leads to a reduction in the overall dimensions of the coupling device. In the coupling device of the present invention, the only portions that do not function to remove foreign matter are the outer peripheral edge and the supported portion. Therefore, compared to the prior art (Patent Document 1) that requires a central opening and the inner and outer peripheral edges of the central opening, the present invention does not require the conventional inner peripheral edge holding margin, and therefore the overall dimensions of the coupling device can be made smaller. [Brief explanation of the drawings]

[0015] [Figure 1]FIG. 1 shows a first embodiment of the present invention, and is a cross-sectional view showing a state in which a first joint and a second joint of a coupling device are separated. [Figure 2] FIG. 2 is a cross-sectional view similar to FIG. 1, showing a state in which the first joint and the second joint of the coupling device are connected. [Figure 3] FIG. 3 is a partial enlarged view of part A shown in FIG. [Figure 4] FIG. 4 shows a second embodiment of the present invention, and is a cross-sectional view showing a state in which the first joint and the second joint of the coupling device are separated. [Figure 5] FIG. 5 is a cross-sectional view similar to FIG. 4, showing a state in which the first joint and the second joint of the coupling device are in contact with each other. [Figure 6] FIG. 6 is a cross-sectional view similar to FIG. 4, showing a state in which the first joint and the second joint of the coupling device are connected. DETAILED DESCRIPTION OF THE INVENTION

[0016] A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2 includes a first joint 3 and a second joint 4 that is detachably connected from the tip side to the first joint 3. A first supply / discharge passage 5 provided in the first joint 3 and a second supply / discharge passage 6 provided in the second joint 4 are separably connected.

[0017] A flow path 7 for compressed air (pressure fluid) formed in the first block 1 is communicated with an attachment hole 8 that opens in the upper surface of the first block 1. A first casing 9 of the first joint 3 is screwed into the attachment hole 8 in a hermetically sealed manner. Furthermore, a flow path 10 for compressed air is formed in the second block 2, and this flow path 10 is communicated with an attachment hole 11 that opens in the lower surface of the second block 2. A second casing 12 of the second joint 4 is inserted into the attachment hole 11 in a hermetically sealed manner.

[0018] In the first joint 3 of the coupling device, an inlet / outlet port 13 is formed by a hole opened in the lower surface of the first casing 9, and a first valve chamber 14 is formed in the upper part of the first casing 9. The first valve chamber 14 and the inlet / outlet port 13 are separated by a partition wall 15, and are connected by six through holes 16 formed in the partition wall 15 (only two through holes 16 are shown in Figures 1 and 2).

[0019] A first filter 17 is attached to the inner peripheral wall of the supply / discharge port 13 so as to cover the supply / discharge port 13. This allows the first filter 17 to remove foreign matter such as dust contained in the compressed air from the supply source.

[0020] A cylindrical first valve member 18 is inserted into the first valve chamber 14 in a hermetically sealed manner so as to be movable up and down. The upper inner circumferential wall of the cylindrical bore 19 of the first valve member 18 is tapered so as to widen as it approaches the top (tip side). An annular first valve surface 20 is formed in this tapered portion. A groove is opened in the circumferential direction on the tip surface of the first valve member 18 outside the first valve surface 20, and an annular sealing member 21 is fitted into this groove.

[0021] A substantially cylindrical valve seat member 22 projects upward into the first valve chamber 14 from the partition wall 15 inside the first casing 9. The upper part of the valve seat member 22 is tapered so as to widen as it extends upward. A first valve seat 23 is formed in the circumferential direction on the tapered surface of the valve seat member 22. The first valve face 20 can abut against the first valve seat 23.

[0022] A first valve closing spring 24 is attached between the cylindrical first valve member 18 and the partition wall 15, and the first valve closing spring 24 urges the first valve member 18 upward toward the tip of the valve seat member 22.

[0023] In this embodiment, the supply / discharge port 13 of the first casing 9, the through hole 16, the first valve chamber 14, and the cylindrical hole 19 of the first valve member 18 form a first supply / discharge passage 5.

[0024] The second joint 4 is configured as follows. A plug portion 25 is formed integrally with the second casing 12 of the second joint 4 so as to protrude downward from the second casing 12, and a receiving surface 26 is formed on the underside of the plug portion 25. The receiving surface 26 is capable of coming into contact with the sealing member 21 attached to the first valve member 18 of the first joint 3. The plug portion 25 is capable of being inserted into the first valve chamber 14 of the first joint 3.

[0025] A second valve chest (sub-valve chest) 27 and a third valve chest (main valve chest) 28 are formed in this order from bottom to top within the second casing 12. The second valve chest 27 and the third valve chest 28 are separated by a partition wall 29 formed within the second casing 12. A guide hole 30 penetrating the center of the partition wall 29 connects the second valve chest 27 and the third valve chest 28. A communication groove 31 is formed in the vertical direction in the peripheral wall of the guide hole 30. The second valve chest 27 opens to the lower surface of the plug portion 25. The third valve chest 28 opens to the upper surface of the second casing 12.

[0026] A second valve seat (sub-valve seat) 32 is formed circumferentially on the inner circumferential wall near the opening of the second valve chamber 27 so as to narrow downward (approach the axis). A second valve member (sub-valve member) 33 is inserted into the second valve chamber 27 and is sealed by a sealing member 34 so as to be movable up and down (in the axial direction of the second casing 12). A recess 35a is formed in the upper part of the second valve member 33, and a support pin (support member) 36 protrudes upward from the bottom wall of the recess 35a. A step 37 is formed in the inner circumferential wall of the recess 35a, and a disk-shaped second filter (filter) 38 is attached to the step 37, with the center of the second filter 38 supported from below by the support pin 36. The chamber defined by the inner peripheral wall of the recess 35a and the second filter 38 communicates with the chamber defined by the outer peripheral surface of the second valve member 33 and the inner peripheral surface of the second valve chamber 28 through six through holes 35b (only two through holes 35b are shown in FIGS. 1 to 3 ) in the cylindrical wall of the second valve member 33. The recess 35a and the through holes 35b form communication 35. The through holes 35b open to the outer peripheral surface of the second valve member 33. More specifically, the opening extends from a sealing portion on the outer peripheral surface of the second valve member 33 that abuts against the sealing member 34 to a second valve surface 41 (described later). A second valve-closing spring 40 is attached between the partition wall 29 and a stepped portion 37 of the recess 35a via the second filter 38. The second valve-closing spring 40 urges the second valve member 33 downward toward the second valve seat 32 against the partition wall 29. A tapered surface is formed on the lower outer peripheral wall of the second valve member 33, and an accommodating groove is opened in the circumferential direction on the tapered surface. A sealing member is fitted into the accommodating groove, and the outer peripheral surface of the sealing member forms a second valve surface (sub-valve surface) 41. The second valve surface 41 is capable of abutting against the second valve seat 32.

[0027] The lower portion of the inner circumferential wall of the third valve chamber 28 is tapered downward (approaching the axis), and a third valve seat (main valve seat) 42 is formed circumferentially on the tapered surface. A third valve member (main valve member) 43 is inserted into the third valve chamber 28 in a hermetically sealed manner and movable up and down (in the axial direction of the second casing 12). The third valve member 43 has, from bottom to top, a cylindrical portion 44 and a tapered portion 45. The cylindrical portion 44 is movably inserted into the guide hole 30. The lower end surface (tip surface) of the cylindrical portion 44 is able to abut against the center of the second filter 38 with a predetermined gap therebetween. The tapered portion 45 is formed to widen upward. A recess 46 is formed in the upper portion of the third valve member 43. A third valve-closing spring 48 is installed between the bottom wall of the recess 46 and a disk-shaped third filter 47 attached to the inner circumferential wall of the second casing 12. The third valve closing spring 48 urges the third valve member 43 downward toward the third valve seat 42 relative to the second casing 12. An accommodation groove is formed in the circumferential direction on the outer peripheral wall of the tapered portion 45 of the third valve member 43. A sealing member is fitted into the accommodation groove, and a third valve surface 49 is formed on the outer peripheral surface of the sealing member. In this embodiment, when the second valve surface 41 is engaged with the second valve seat 3 and the third valve surface 49 is engaged with the third valve seat 42, the lower end surface of the cylindrical portion 44 is spaced a predetermined distance from the center of the second filter 38; however, the lower end surface of the cylindrical portion 44 may abut against the center of the second filter 38 in the above state.

[0028] As described above, the third valve closing spring 48 is mounted between the third valve member 43 and the thin third filter 47. For this reason, it is necessary to prevent the third filter 47 from being plastically deformed or damaged by the biasing force of the third valve closing spring 48. Therefore, the maximum biasing force of the third valve closing spring 48 is set to be sufficiently smaller than the maximum biasing force of the second valve closing spring 40. However, in certain cases, the third valve closing spring 48 must also press the third valve member 43. For this reason, the biasing force of the third valve closing spring 48 must be set to be greater than the resistance forces of the third valve member 43, such as its own weight and sliding resistance.

[0029] The second filter 38 and the third filter 47 are configured in substantially the same manner. Their configuration will be described with reference to FIG. 3 , which shows the second filter 38. The filter 38 includes, in order from the bottom, a lower support member 50, a lower spacer 51, a wire mesh 52, an upper spacer 53, and an upper support member 54. The lower support member 50 is a disk-shaped plate with multiple circular holes (a so-called punched metal). Its central portion is formed to protrude upward. An annular lower spacer 51 is attached to the outer edge of the lower support member 50, and a circular wire mesh 52 is attached to the lower spacer 51. This creates a gap between the lower support member 50 and the wire mesh 52, approximately the thickness of the lower spacer 51, allowing the compressed air to flow smoothly through the gap. An upper spacer 53 (the same material as the lower spacer) is attached to the outer edge of the wire mesh 52, and a disk-shaped upper support member 54 is attached to the upper spacer 53. This also forms a gap between the wire mesh 52 and the upper support member 54, allowing the compressed air to flow smoothly through the gap. The upper support member 54 is made of the same material as the lower support member 50 and has the same external dimensions and thickness, but does not have the protrusion 55 that the lower support member 50 has. The wire mesh 52 is sandwiched between the protrusion 55 of the lower support member 50 and the central portion of the upper support member 54.

[0030] The second filter 38 is inserted into the recess 35a of the second valve member 33 and is received from below by the stepped portion 37 of the second valve member 33. A fixing ring 56 is press-fitted into the recess 35a of the second valve member 33 from above the second filter 38 and fixed thereto, or the fixing ring 56 is inserted into the recess 35a and a portion of the inner circumferential wall of the recess 35a is plastically deformed to fix the second filter 38 in place.

[0031] As shown in Figures 1 and 2, the above-described coupling device is connected and disconnected as follows. First, as shown in Figure 1, the second block 2 is separated from the first block 1, and the coupling device is in a disconnected state. In the first joint 3 in this disconnected state, the first valve closing spring 24 urges the first valve member 18 toward the tip of the valve seat member 22 against the partition wall 15 of the first casing 9. As a result, the first valve face 20 of the first valve member 18 engages with the first valve seat 23 of the valve seat member 22, and the valve is closed.

[0032] With the second joint 4 in the above-described disengaged state, the second valve member 33 is urged downward toward the second valve seat 32 by the second valve closing spring 40. As a result, the second valve surface 41 of the second valve member 33 engages with the second valve seat 32, and the valve is closed. In addition, the third valve member 43 is urged downward toward the third valve seat 42 by the third valve closing spring 48. As a result, the third valve surface 49 of the third valve member 43 engages with the third valve seat 42, and the valve is closed.

[0033] When the second block 2 is brought closer to the first block 1 in order to be connected from the above-described separated state, first, the receiving surface 26 of the plug portion 25 of the second joint 4 engages with the sealing member 21 of the first joint 3. At this time, the second valve member 33 of the second joint 4 engages with the valve seat member 22 of the first joint 3. Next, the plug portion 25 moves the first valve member 18 downward against the biasing force of the first valve-closing spring 24. As a result, the first valve surface 20 is separated from the first valve seat 23, and the valve is opened. Furthermore, as the plug portion 25 is inserted into the first valve chamber 14, the second valve member 33 is received by the valve seat member 22, and the second valve member 33 is left in an engagement position with the valve seat member 22 relative to the plug portion 25. As a result, the second valve surface 41 is separated from the second valve seat 32, and the valve is opened. Next, the third valve member 43 abuts against the second filter 38 and is received by the second valve member 33 via the second filter 38 and the support pin 36, so that the third valve member 43 is left in an engagement position with the second filter 38 relative to the plug portion 25. This causes the third valve face 49 to move away from the third valve seat 42, opening the valve. Subsequently, the lower surface of the second casing 12 is received by the upper surface of the first casing 9, and the first joint 3 and second joint 4 are switched from the disengaged state shown in FIG. 1 to the connected state shown in FIG. 2.

[0034] In the coupling device of this embodiment, a switching valve (not shown) is provided midway through the flow path 7 formed in the first block 1. The switching valve switches between a state in which the coupling device is connected to the compressed air supply source and a state in which the coupling device is connected to the discharge port.

[0035] When compressed air is supplied from a compressed air supply source to an actuator (not shown) through the coupling device in the connected state shown in FIG. 2 , the compressed air flows through the coupling device as follows: First, compressed air from the supply source flows through the flow path 7 into the supply / discharge port 13 of the first joint 3. Then, it passes through the first filter 17 and the through-hole 16 and is supplied to the first valve chamber 14. The compressed air in the first valve chamber 14 flows into the second valve chamber 27 through the valve-opening gap formed between the first valve face 20 and the first valve seat 23 and the valve-opening gap formed between the second valve face 41 and the second valve seat 32. Next, the compressed air in the second valve chamber 27 passes through the second filter 38, the communicating groove 31, the valve-opening gap formed between the third valve face 49 and the third valve seat 42, and the third filter 47 before being supplied to the actuator.

[0036] When the compressed air in the actuator is to be discharged to the outside, the switching valve is used to switch the coupling device so that it is connected to the discharge port, and the compressed air in the actuator is then discharged to the outside from the discharge port in the reverse order of the above.

[0037] The above first embodiment has the following advantages. The recess 35a and through-hole 35b formed in the upper part of the second valve member 33 constitute part of the second supply / discharge passage 6. That is, part of the second supply / discharge passage 6 is provided inside the second valve member 33. Therefore, the radial dimension of the second joint 4 of this embodiment can be made smaller than in the prior art described above, in which the supply / discharge passage and the ring-shaped filter are provided on the outside of the valve member.

[0038] Additionally, a second filter 38 is attached to the recess 35a serving as the second supply / discharge path 6 inside the second valve member 33. In this respect, the radial dimension of the second joint 4 in this embodiment can be made smaller than in the prior art in which a ring-shaped filter is provided on the outer periphery of the valve chest.

[0039] The conventional coupling device described above includes a thin, ring-shaped filter with a central opening. In this case, the inner and outer edges of the filter opening must be pressed and fixed to prevent the filter from being pressed by the pressure of compressed air, creating gaps and reducing its functionality. Because compressed air cannot flow through the filter's opening or its inner and outer peripheral edges, the filter must be sufficiently wide radially outward. In contrast, in the second coupling 4 of this embodiment, the outer peripheral edge of the second filter 38 is supported by the stepped portion 37 of the second valve member 33, and the center of the second filter 38 is supported by the support pin 36 of the second valve member 33. Therefore, compressed air does not flow through the area where the outer peripheral edge abuts the support pin 36, but does flow through areas other than the outer peripheral edge and the abutting area. Therefore, the area through which compressed air can flow can be increased by the amount of the pressing margin of the inner peripheral edge compared to the conventional technology. Therefore, the second filter of this embodiment can be made smaller radially than the ring-shaped filter of the conventional technology. Therefore, the overall size of the coupling device can be made small.

[0040] A protrusion 55 is formed in the center of the lower support member 50 of the second filter 38, and the wire mesh 52 is sandwiched between the protrusion 55 and the center of the upper support member 54. In other words, the wire mesh 52, the protrusion 55, and the center of the upper support member 54 are abutted against each other, with no gap between them, or they are so close together that there is almost no gap between them. As a result, when the second valve member 33 pushes the third valve member 43 upward or returns it downward via the support pin 36 and the second filter 38, the components that make up the filter 38 are less likely to bend or return due to the third valve member 43 and the support pin 36, and therefore damage or wear to the second filter 38 due to the repeated or alternating load can be prevented.

[0041] Furthermore, a lower spacer 51 is attached between the outer edge of the lower support member 50 and the wire mesh 52, and an upper spacer 53 is attached between the upper support member 54 and the wire mesh 52. This forms a space between the wire mesh 52 and the lower support member 50, or between the wire mesh 52 and the upper support member 54, and compressed air flows through this space. Even if the positions of the holes in the lower support member 50 and the upper support member 54 are misaligned in the horizontal direction, the compressed air from the holes in the lower support member 50 flows reliably through the space and the wire mesh 52, etc., to the holes in the upper support member 54.

[0042] Furthermore, the third valve member 43 is inserted into a chamber partitioned by the second filter 38, second valve member 33, second valve chamber 27, third valve chamber 28, and third filter 47. As a result, foreign matter such as dust contained in the compressed air from the supply source is removed by the first filter 17, and foreign matter contained in the compressed air from the actuator is removed by the second filter 47. As a result, when the second joint is closed, foreign matter is prevented from becoming caught between the third valve face and the third valve seat of the third valve member, which would cause fluid to leak.

[0043] 4 to 6 show a second embodiment of the present invention. In this second embodiment, components that are the same as (or similar to) those in the first embodiment will be described with the same reference numerals as in the first embodiment.

[0044] The second embodiment differs from the first embodiment in the following respects. In the coupling device of the second embodiment, three grooves are formed in the outer peripheral wall of the first casing 9 of the first joint 3 in the circumferential direction at different heights, and sealing members are attached to the uppermost and lowermost of the three grooves. The middle groove of the three grooves is connected to the first flow path 7 formed in the first block 1. A hole opening in the bottom surface of the middle groove forms the supply / discharge port 13. The supply / discharge port 13 is connected to a first valve chamber 14 formed in the upper part of the first casing 9. Note that although the first filter 17 is omitted in this embodiment, it may be provided to cover the supply / discharge port 13.

[0045] A cylindrical support cylinder 60 protrudes from the bottom wall of the first valve chamber 14, and a valve seat member 62 is inserted into a cylindrical bore 61 of the support cylinder 60 so as to be movable up and down. A mounting groove is formed in the lower part of the valve seat member 62, and a retaining ring is mounted in the mounting groove as a stopper. The retaining ring prevents the valve seat member 62 from slipping upward from the cylindrical bore 61 of the support cylinder 60. The upper part of the valve seat member 62 is tapered so as to widen upward. A first valve seat 63 is formed on the tapered surface of the valve seat member 62 in the circumferential direction. The first valve surface 20 can abut against the first valve seat 63. A first valve closing spring 24 is mounted between the bottom wall of the first valve chamber 14 and the cylindrical first valve member 18, and the first valve closing spring 24 urges the first valve member 18 upward toward the tip of the valve seat member 62.

[0046] A cylinder bore 66 is formed across a partition wall 65 formed below the first valve chamber 14. A through-hole 67 is formed in the partition wall 65, and the first valve chamber 14 and the cylinder bore 66 are connected by the through-hole 67. A piston 68 is inserted into the cylinder bore 66 in a hermetically sealed manner so as to be movable up and down. A working chamber 69 is formed below the piston 68, and compressed air from a supply source is supplied to and discharged from the working chamber 69 through a supply / discharge passage 70 formed in the first block 1. In this embodiment, the supply / discharge port 13 of the first casing 9, the first valve chamber 14, and the cylindrical bore 19 of the first valve member 18 form the first supply / discharge passage 5. In this embodiment, the piston 68 and the valve seat member 62 are formed as separate members, but they may also be formed as a single unit.

[0047] In the second joint 4 of this embodiment, a receiving surface 71 is formed on the lower surface of the second casing 12. The receiving surface 71 is capable of coming into contact with the sealing member 21 attached to the first valve member 18 of the first joint 3. In the second joint 4 of this embodiment, the plug portion 25 of the second joint 3 of the first embodiment is omitted.

[0048] As shown in Figures 4 to 6, the above-mentioned coupling device is connected and disconnected as follows. First, in the disconnected state of the coupling device shown in Figure 4, in the first joint 3, the first valve-closing spring 24 presses the first valve member 18 upward, and the first valve member 18 presses the valve seat member 62 to the upper limit position. As a result, the first valve surface 20 of the first valve member 18 engages with the first valve seat 63 of the valve seat member 62, and the valve is closed.

[0049] With the second joint 4 in the above-described disengaged state, the second valve closing spring 40 presses the second valve member 33 downward toward the second valve seat 32. As a result, the second valve surface 41 of the second valve member 33 engages with the second valve seat 32, and the valve is closed. In addition, the third valve closing spring 48 urges the third valve member 43 downward toward the third valve seat 42. As a result, the third valve surface 49 of the third valve member 43 engages with the third valve seat 42, and the valve is closed.

[0050] When the second block 2 is moved closer to the first block 1 to connect them from the above-described separated state, the receiving surface 71 of the second joint 4 first engages with the sealing member 21 of the first valve member 18 of the first joint 3. Next, as shown in FIG. 5 , the second casing 12 moves the first valve member 18 downward against the biasing force of the first valve-closing spring 24, and the second casing 12, via the second valve-closing spring 40 and the second valve member 33, moves the valve seat member 62 downward. At this time, the first valve surface 20 engages with the first valve seat 63, maintaining the valve-closed state, and the second valve surface 41 engages with the second valve seat 32, maintaining the valve-closed state. The second casing 12 is then received by the first casing 9. Next, when compressed air from the supply source is supplied to the working chamber 69 through the supply / discharge path 70, the piston 68 rises and abuts against the valve seat member 62. Subsequently, the piston 68 moves the second valve member 33 upward via the valve seat member 62 against the biasing force of the second valve-closing spring 40. As a result, the first valve face 20 moves away from the first valve seat 63, opening the valve, and the second valve face 41 moves away from the second valve seat 32, opening the valve. Next, the second filter 38 attached to the second valve member 33 engages with the third valve member 43. Thereafter, the piston 68 moves the third valve member 43 upward via the valve seat member 62, the second valve member 33, and the second filter 38. As a result, the third valve face 49 moves away from the third valve seat 42, opening the valve. Thereafter, the piston 68 is received by a step formed on the inner circumferential wall of the cylinder bore 66. As a result, the first joint 3 and the second joint 4 are switched from the disengaged state shown in FIG. 4 to the coupled state shown in FIG. 6.

[0051] A switching valve (not shown) provided midway along the supply / discharge path 7 switches from a state in which the coupling device is connected to the discharge port to a state in which the coupling device is connected to the compressed air supply source. Compressed air from the supply source is then supplied to the actuator (not shown) through the first supply / discharge path 5 and second supply / discharge path 6 of the coupling device. The compressed air from the supply source flows through the coupling device as follows: First, compressed air from the supply source is supplied to the first valve chamber 14 through the flow path 7 and the first supply / discharge port 13. The compressed air in the first valve chamber 14 then flows into the second valve chamber 27 through the valve-opening gap formed between the first valve face 20 and the first valve seat 63 and the valve-opening gap formed between the second valve face 41 and the second valve seat 32. The compressed air in the second valve chamber 27 is then supplied to the actuator through the second filter 38, the communicating groove 31, the valve opening gap formed between the third valve face 49 and the third valve seat 42, the third filter 47, and the flow path 10.

[0052] When the compressed air in the actuator is to be discharged to the outside, the switching valve is used to switch the coupling device so that it is connected to the discharge port, and the compressed air in the actuator is then discharged to the outside from the discharge port in the reverse order of the above.

[0053] The above embodiments can be modified as follows. The pressure fluid may be other gases or liquids such as pressure oil instead of compressed air as exemplified above. Instead of the lower surface of the second casing 12 being received on the upper surface of the first casing 9, a supported member 73 provided on the second block 2 may be received on a supporting member 72 provided on the first block 1, as shown in Figure 4. Instead of fitting the sealing member 34 in a housing groove formed in the circumferential direction on the inner peripheral wall of the second valve chamber 27, the sealing member 34 may be fitted in a housing groove formed on the outer peripheral wall of the second valve member 33. In this case, the abutting portion between the sealing member 34 and the inner peripheral wall of the second valve chamber 27 with which the sealing member 34 abuts is referred to as the sealed portion. Of course, various other modifications can be made within the scope of what can be imagined by those skilled in the art. [Explanation of symbols]

[0054] 3: First joint, 4: Second joint, 5: First supply and discharge passage, 6: Second supply and discharge passage, 27: Second valve chamber (auxiliary valve chamber), 28: Third valve chamber (main valve chamber), 32: Second valve seat (auxiliary valve seat), 33: Second valve member (auxiliary valve member), 34: Sealing member, 35: Connecting passage, 36: Support pin (support member), 38: Second filter (filter), 40: Valve closing spring, 41: Sub-valve surface (second valve surface), 42: Third valve seat (main valve seat), 43: Third valve member (main valve member), 48: Valve closing spring.

Claims

1. A first joint (3), a second joint (4) detachably connected to the first joint (3); a first supply / discharge passage (5) provided in the first joint (3); a second supply / discharge passage (6) provided in the second joint (4) and detachably connected to the first supply / discharge passage (5); a sub-valve chamber (27) and a main valve chamber (28) formed in the second joint (4) so ​​as to be continuous from the tip end side to the base end side in the axial direction; a sub-valve member (33) that is movable in the axial direction within the sub-valve chamber (27), is inserted in a hermetically sealed manner via a sealing member (34), and is biased by a second valve closing spring (40) toward a tip end side of a sub-valve seat (32) formed within the sub-valve chamber (27), the sub-valve member (33) having a sub-valve surface (41) that can come into contact with the sub-valve seat (32); a main valve member (43) that is axially movable and hermetically inserted into the main valve chamber (28) and that is capable of contacting the sub-valve member (33), the main valve member (43) being biased by a third valve closing spring (48) toward a tip end side of a main valve seat (42) formed in the main valve chamber (28), a communication passage (35) as a part of the second supply / discharge passage (6) is formed in the sub-valve member (33), and a filter (38) is attached to a midpoint of the communication passage (35).

2. 2. The coupling device of claim 1, One end of the communication passage (35) is open on the outer peripheral surface of the sub-valve member (33) between a portion sealed by the sealing member (34) and the sub-valve surface (41), The other end of the communication passage (35) is located between the sub-valve member (33) and the main valve member (43) and communicates with the sub-valve chamber (27).

3. In the coupling device of claim 1 or 2, A support member (36) protruding from the wall surface of the communication passage (35) supports the disk-shaped filter (38), A coupling device characterized in that the sub-valve member (33) can abut against the main valve member (43) via the support member (36) and the filter (38).

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