Rohrkupplung

Abstract

A pipe coupling comprising a base body (12; 102) in the interior of which a flow path (22, 24) is provided through which a fluid flows, a fastening element (40; 106, 110) which is screwed onto one end of the base body (12; 102) and is movable forwards and backwards thereon and serves to connect a pipe (38; 104, 108) through which the fluid flows to one end, and a confirmation ring (48; 112) which is arranged between the base body (12; 102) and one end of the fastening element (40; 106, 110), wherein the pipe coupling is configured such that, when the pipe (38; 104, 108) is fastened by the fastening element (40; 106, 110), the fastening element (40; 106, 110) moves to one side of the base body (12; 102) and presses the confirmation ring (48; 112), whereby an outer edge portion of the confirmation ring (48; 112) is gripped between the fastening element (40) and the base body (12) and thereby deformed, so that the outer edge portion of the confirmation ring (48; 112) is exposed to the surroundings of the fastening element (40; 106, 110), characterized in that additionally at least one projection (54a, 54b; 116) is provided on the outer edge portion of the confirmation ring (48; 112), wherein the projection (54a, 54b; 116) projects outwardly from the outer edge portion of the confirmation ring (48; 112) in a radial direction of the confirmation ring (48; 112) when the outer edge portion of the confirmation ring (48; 112) is deformed by fastening the fastening member (40).

Description

BACKGROUND OF THE INVENTIONThe present invention relates to a pipe joint connecting pipes or hoses through which a fluid is supplied or discharged, for example.The present applicant has proposed, for example, in Japanese Patent JP 5 360 619 B2, a pipe coupling for connecting a fluid pipe to a fluid pressure device, for example, a cylinder or the like, in which a connection state of the fluid pipe can be checked from the outside.The tube coupling includes a base body having a fluid passage in an interior thereof, a fixing cap screwed and connecting a tube to the base body, and an indicator ring provided between a stopper member of the base body and an end of the fixing cap. The indicator ring includes a flat portion and an inclined portion inclined relative to the flat portion, and has a smaller diameter than an outer circumferential surface of the fixing cap.When the fixing cap is screwed to thereby connect the pipe, the inclined portion is pressurized and deformed by the movement of the fixing cap. Thereby, the inclined portion protrudes radially outward from the outer circumferential surface of the fixing cap, whereby the tightened state is recognizable by the outer edge of the indicator ring.SUMMARY OF THE INVENTIONIt is a general object of the present invention to provide a pipe coupling with which a connection state of a pipe to a main body can be checked even more easily and reliably.This object is achieved with the invention substantially by the features of claim 1.Advantageous embodiments of the invention are evident from the dependent claims.The present invention is characterized by a pipe coupling including a body having a flow path inside which a fluid flows, a fixing member screwed on and movable forward and backward on one end of the body and serving to connect a pipe through which the fluid flows to the end, and a confirmation ring provided between the body and one end of the fixing member and exposed to the outside relative to the fixing member when the pipe is fixed by the fixing member. At least one or more protrusions are provided on an outer edge portion of the confirmation ring and project diametrically outward from the outer edge portion when the operation ring is deformed by being gripped by the fastening operation of the fastening member between the fastening member and the base body.According to the present invention, the confirmation ring is provided between the main body inside which the flow path is provided and the fixing member which can move forward and backward on the end of the main body and serves to connect the pipe. It is exposed outwardly relative to the fastener when the tube is fastened by the fastener. In addition, when the pipe is connected to the main body, the fixing member that can move forward and backward on the end of the main body moves to the side of the confirmation ring and presses the confirmation ring, thereby deforming the confirmation ring so that the outer edge portion of the confirmation ring is exposed (exposed) to the outside. In addition, the protrusion protrudes to the outside of the edge portion.Accordingly, by checking the state of attachment of the fastener to the base body with the aid of the protrusion protruding outward from the outer edge portion of the confirmation ring, this check can be performed more easily and with better reliability. Therefore, it is possible to easily and reliably check whether or not a connected state of the pipe has been realized by the fastening member. At the same time, leakage of fluid between the tube and the base body can be prevented more reliably.Other features, objects and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings. All features described and / or graphically depicted form the subject matter of the invention by themselves or in any combination, irrespective of their summary or their relational expression.Brief Description of the DrawingsFIG. 1 is a partial cross-sectional view of an on / off valve in which pipe couplings according to a first embodiment of the present invention are used; FIG. 2 is a front view of the on / off valve of FIG. 1 ; FIG. 3 is a partially broken-away plan view of the on / off valve of FIG. 1 ; FIG. 4 is a perspective view of an indicator ring forming part of the on / off valve of FIG. 1 ; FIG. 5 is a partially broken-out plan view showing a state before fitting the pipe connectors in the on / off valve of FIG. 4 ; FIG. 6A is a front view of a pipe joint according to a second embodiment of the present invention; FIG. 6B is a front view in which the pipe joint of FIG. 6A is viewed from its one end side; FIG. 7A is an enlarged front view showing a state before the fixing cap is fixed in the pipe joint of FIG. 6A ; and FIG. 7B is a front view in which the pipe joint of FIG. 7A is viewed from its one end side.DESCRIPTION OF THE PREFERRED EMBODIMENTIn the following, an on / off valve used with a pipe coupling according to a first embodiment of the present invention is described by way of example (the term pipe in the sense of the present invention generally covers fluid lines, in particular also hoses). As shown in FIGS. 1 to 3, an on / off valve 10 includes a main body 12 having a flow path through which a pressurized fluid flows, and a valve mechanism 14 disposed inside the main body 12, and connecting mechanisms 20 serving as pipe couplings are provided respectively at a first port 16 and a second port 18 formed at one end and the other end of the main body 12.In the interior of the main body 12, the first port 16 is also connected to a first flow path 22, and the second port 18 is connected to a second flow path 24. In addition, a partition wall 26 is provided at a transition portion between the first flow path 22 and the second flow path 24, and a valve seat 30 is provided at one end thereof, on which a valve body 28 of the valve mechanism 14 can be seated.Furthermore, cylindrical guide members 32 are formed on outer circumferential sides of the first terminal 16 and the second terminal 18. Connection members 34 are also formed on outer circumferential sides of the guide members 32. The connecting elements 34 have a cylindrical shape and have external threads 36 on their outer circumferential surfaces. Tubes 38 are inserted between the guide members 32 and the joint members 34. Fastening caps 40 of the link mechanisms 20 are screwed on outer circumferential sides of the link members 34.The fixing cap 40 has a cylindrical shape and has a large diameter portion 42 screwed to the connecting member 34 and a small diameter portion 46 in which a pipe hole 44 through which the pipe 38 is inserted is formed. An internal thread portion is formed on an inner circumferential surface of the large diameter portion 42.By screwing the fixing caps 40 onto the joint members 34 of the base body 12 in a state in which the tubes 38 are inserted through the fixing caps and sliding to the base body 12 side (in the directions of the arrows A 1), ends of the tubes 38 are gripped and held between the small-diameter portion 46 of the fixing caps 40, the guide members 32, and the joint members 34.In addition, indicator rings (confirmation rings) 48 are provided between the base body 12 and the ends of the fastening caps 40.As shown in FIGS. 1 to 4, the indicator rings 48 are formed of, for example, an elastically deformable resin material and have a fixed width in the radial direction and a ring shape having a substantially constant thickness. As shown in FIG. 4, the indicator rings 48 each include an annular flat portion 50 at a substantially central portion, an inclined portion 52 inclined and extending from an outer edge portion of the flat portion 50 at a right angle relative to the flat portion 50, and a pair of protrusions 54 a, 54 bprotruding outward from the outer edge portion of the inclined portion 52.The flat portions 50 are formed substantially flat and fitted and held on the outer circumferential sides of the connecting members 34 of the main body 12 through openings 56 formed in the center of the flat portions 50.In the inclined portions 52, a plurality of slits 58 are provided, which are inclined by about 120° relative to the flat portions 50. They extend radially inward from the outer edge portion of the inclined portions 52 and are spaced apart from each other at substantially equal angular intervals in the circumferential direction.The protrusions 54 a, 54 bare formed to protrude from the outer edge portions of the inclined portions 52 with fixed lengths in axial directions (the directions of the arrow A) of the indicator rings 48. They have, for example, a rectangular cross section and are arranged at symmetrical positions relative to the centers of the indicator rings 58. In addition, the protrusions 54 a, 54 bare not limited to being provided in pairs as long as at least one or more of these protrusions is provided. Its amount is not particularly limited and can be arbitrarily selected as necessary.The indicator rings 48 are inserted through the openings 56 into the connecting elements 34 of the base body 12 and are arranged on fastening sections 62 between the thread 36 and outer wall sections 60 of the base body 12. As a result, their flat portions 50 abut against the outer wall portions 60, and the projections 54 a, 54 bare provided in a state of extending in directions (the directions of the arrows A 2) away from the outer wall portions 60 of the base body 12.The on / off valve 10 using the pipe coupling (link mechanism 20) according to the first embodiment of the present invention is configured substantially as described above. Next, a case where the tubes 38 are joined to the base body 12 will be described. First, a preparation state in which the tubes 38 and the fixing caps 40 are not yet attached to the first and second terminals 16, 18 of the main body 12 will be described.In the above-described preparation state, an unillustrated operator first grasps the indicator rings 48 and inserts the indicator rings 48 onto the connecting members 34 of the base body 12 through the openings 56 thereof. Here, the indicator rings 48 are inserted so that their flat portions 50 are positioned on the sides of the outer wall portions 60 of the body 12 in the directions of the arrows A 1. Here, the protrusions 54 a, 54 bare in a state of protruding in directions (the directions of the arrows A 2) away from the main body 12.Moreover, as shown in FIG. 5, after the indicator rings 48 are inserted between the threads 36 and the outer wall portions 60 into the fastening portions 62, the flat portions 50 are brought into abutment against the outer wall portions 60.Next, after the ends of the tubes 38 are inserted to a point between the guide members 32 and the joint members 34 of the main body 12, in a state where the tubes 38 are inserted into the tube openings 44, by screwing and rotating the fixing caps 40 onto the joint members 34, the fixing caps 40 are moved toward the sides of the main body 12 (in the directions of the arrows A1).Since the ends of the fixing caps 40 do not abut against the inclined portions 52 of the indicator rings 48, the inclined portions 52 remain in a state inclined relative to the flat portions 50. Also, the protrusions 54 a, 54 bare in a state of extending in the axial direction (the directions of the arrows A 2). Therefore, the operator does not see the projections 54a, 54b of the indicator rings 48 from the sides of the main body 12, and the tubes 38 are not erroneously recognized as being in a connected state.By screwing and further moving the fixing caps 40, the ends of the fixing caps 40 come into contact with the inclined portions 52 of the indicator rings 48, and the inclined portions 52 are gradually pressed toward the sides of the outer wall portions 60 (in the directions of the arrows A 1).Accordingly, the inclined portions 52 are deformed so that the inclination angle thereof to the connection with the flat portions 50 becomes gradually larger relative to the flat portions 50, so that the outer diameters of the indicator rings 48 are gradually increased. Thereby, the inclined portions 52 of the indicator rings 48 are deformed so as to gradually protrude from the outer circumferential surfaces of the fixing caps 40. At the same time, the protrusions 54 a, 54 bprovided at the outer edge portions are inclined so as to gradually rise upward.Finally, as shown in FIG. 3, the inclined portions 52 are deformed by the ends of the fixing caps 40 until they become substantially coplanar with the flat portions 50. A state is established in which the outer edges of the indicator rings 48 protrude beyond the outer circumferential surfaces of the fixing caps 40, and at the same time, the protrusions 54 a, 54 bprotrude diametrically outward in a state of being inclined at a certain angle in directions (the directions of the arrows A 2) away from the base body 12.As shown in FIGS. 1 to 3, the fastening caps 40 are hereby fully screwed onto the base body 12. By reliably connecting the tubes 38 to the connection members 34 of the main body 12, a final state is achieved in which one of the tubes 38 is brought into communication with the first port 16 and the first flow path 22. In addition, the other of the tubes 38 is communicated with the second port 18 and the second flow path 24.Specifically, the protrusions 54 a, 54 bof the indicator rings 48 protrude further outward from the outer circumferential surfaces of the fixing caps 40. They project so as to be inclined in directions (the directions of the arrows A 2) away from the outer wall portions 60 of the base body 12. Therefore, the operator can easily check and confirm that the fixing cap 40 is fully tightened and that the tube 38 is reliably connected to the main body 12 by observing the indicator rings 48 from the sides of the main body 12. In addition, when it is difficult to visually recognize the projections 54 a, 54 b, it is possible for the operator to check the connection state by touching the projections 54 a, 54 bwith the hand.Next, the operation of the on / off valve 10 to which the pipes 38 are connected by the above-described connecting mechanism 20 will be briefly described.First, as shown in FIG. 1, by supplying a pressurized fluid to a fluid supply port 64 aprovided on the main body 12, a valve open state is established in which the valve body 28 of the valve mechanism 14 is moved in a direction of being separated from the valve seat 30. Then, the pressure fluid flows from the first port 16 through the first and second flow paths 22, 24 to the second port 18 and is supplied to another fluid pressure device through the pipe 38.On the other hand, when the valve is open (valve open state), by supplying a pressurized fluid to another fluid supply port 64 bin the valve closing main body 12, a valve closed state is established in which the valve body 28 of the valve mechanism 14 is moved in a direction toward the valve seat 30 side and seats thereon. This blocks the connection between the first connection 16 and the second connection 18.In the on / off valve 10 having the connection mechanism 20, in the first embodiment, in this manner, when the tubes 38 are connected to the connection members 34 of the main body 12, the annular indicator rings 48 are disposed on the attachment portions 62 of the main body 12. By moving the fixation caps 40 screwed to the connection members 34 and pressing and deforming the inclined portions 52 of the indicator rings 48 by the ends of the fixation caps 40, the pairs of protrusions 54 a, 54 bprovided on the outer circumferential sides of the inclined portions 52 can be made to protrude from the outer circumferential sides of the fixation caps 40. At the same time, the pairs of projections 54a, 54b may be tilted and made to project in directions (the directions of the arrows A2) away from the outer wall portions 60 of the base body 12.Thereby, the state of attachment of the attachment caps 40 to the base body 12 can be visually checked easily and reliably using the protrusions 54 a, 54 bprotruding from the attachment caps 40. In addition, the mounting state can also be easily and reliably checked by manually scanning the projections 54a, 54b. Thus, as compared with the conventional pipe joint, the connection state of the pipes 38 by the fixing caps 40 can be checked more easily and reliably. The leakage of fluid between the tubes 38 and the base body 12 can be reliably prevented.Next, a pipe coupling 100 according to a second embodiment is shown in FIGS. 6A to 7B.As shown in FIG. 6A, the pipe joint 100 includes a base body 102 having an L-shaped cross section, a first fixing cap 106 screwed on one end portion of the base body 102 and connecting a first pipe 104 thereto, a second fixing cap 110 screwed on another end portion of the base body 102 and connecting a second pipe 108 thereto, and a pair of indicator rings (confirmation rings) 112 gripped between the base body 102 and the first and second fixing caps 106, 110, respectively.The first tube 104 and the second tube 108 have different diameters and are made of, for example, a resin or plastic material. The diameters of the one end portion and the other end portion of the main body 102 to which the first and second pipes 104, 108 are connected are also different.The main body 102 is formed such that the first tube 104 is joined by screwing the first fixing cap 106 onto a connecting member (not shown) formed at one end portion of the main body 102, and the second tube 108 is joined by screwing the second fixing cap 110 onto a connecting member formed at the other end portion of the main body 102.In addition, the indicator ring 112 is disposed between an end of the first fixing cap 106 and a stopper wall 114 aof the main body 102. In the same manner, the indicator ring 112 is disposed between an end of the second attachment cap 110 and a stopper wall 114 bof the main body 102. The stopper walls 114 a, 114 bare formed annularly and project diametrically outward at fixed heights.The indicator ring 112 has a single protrusion 116 at an outer edge portion of the inclined portion 52, so that in a state before being fixed by the first fixing cap 106, the protrusion 116 is formed to be substantially parallel to the axis of the first fixing cap 106 (see FIGS. 7A and 7B ).Next, a situation in which the first pipe 104 is joined to an end portion of the main body 102 by the first fixing cap 106 will be described.First, as shown in FIG. 7A, in a state in which the first fixing cap 106 is screwed on the connector formed at the one end portion of the main body 102 and the first tube 104 inserted through the first fixing cap 106 is inserted into the inside of the connector, the protrusion 116 of the indicator ring 112 is in a substantially parallel state to the outer circumferential surface of the first fixing cap 106 and is located more inward in the circumferential direction than the stopper wall 114 a. Therefore, as shown in FIG. 7B, the operator cannot see the protrusion 116 from the base body 102 side, and it is not accidentally assumed that the first pipe 104 is in a connected state.Now, by the operator screwing and moving the first fixing cap 102 to the side of the base body 102, the inclined portion 52 of the indicator ring 112 is gradually pressed toward the stopper wall 114 aside (in the direction of the arrow A 1) by the end of the first fixing cap 106. Accordingly, the inclined portion 52 is deformed so that its inclination angle becomes gradually larger around the connection area with the flat portion 50 relative to the flat portion 50. Thereby, at the same time, the outer diameter of the indicator ring 112 is gradually increased, and the protrusion 116 provided at its outer edge portion is inclined to gradually rise upward.Finally, as shown in FIG. 6A, the inclined portion 52 is deformed by the end of the first fixing cap 106 until it becomes substantially coplanar with the flat portion 50, and a state is established in which the protrusion 116 protrudes diametrically outward (see FIGS. 6A and 6B ) in a state inclined by a predetermined angle along the direction (the direction of the arrow A 2) away from the stopper wall 114 a.Thereby, the first fixing cap 106 is fully screwed on the main body 102, the first tube 104 is reliably connected to the main body 102, and an engagement state is established in which the first tube 104 and the fluid passage communicate with each other.Specifically, the protrusion 116 of the indicator ring 112 protrudes outward from the outer circumferential surface of the first fixing cap 106 and protrudes so as to be inclined in a direction (the direction of the arrow A 2) away from the stopper wall 114 a. Therefore, the operator can easily determine that the first fixing cap 106 is fully tightened and that the first tube 104 is reliably connected to the main body 102 by observing the indicator ring 112 from the side of the main body 102.When it is difficult to recognize the protrusion 116, the operation position can also check the connection state by manually touching and sensing the protrusion 116, which is separated from the stopper wall 114 aand protrudes further diametrically outward beyond the stopper wall 114 a.In the above-described manner, in the second embodiment, with the pipe joint 100 in which the first and second pipes 104, 108 having different diameters are joined on the one end side and the other end side of the main body 102, for example, even in the case where the outer diameters of the indicator rings 112 are smaller than the stopper walls 114 a, 114 bof the main body 102 against which the ends of the first and second fixing caps 106, 110 abut, by using the indicator ring 112 having the protrusion 116 at its outer edge portion, when the first pipe 104 is joined, the protrusion 116 can be made to protrude further outward than the stopper wall 114 a. Thus, the connection state of the first pipe 104 can be easily and reliably checked.

Claims

A pipe coupling comprising a main body (12; 102) having provided therein a flow path (22, 24) through which a fluid flows, a fixing member (40; 106, 110) screwed on and movable forward and backward on one end of the main body (12; 102) and for connecting a pipe (38; 104, 108) through which the fluid flows to the one end, and a confirmation ring (48; 112) disposed between the main body (12; 102) and one end of the fixing member (40; 106, 110), wherein the pipe coupling is configured such that, when the pipe (38; 104, 108) is fixed by the fixing member (40; 106, 110), the fixing member (40; 106, 110) moves to one side of the main body (12; 102) and the confirmation ring (48; 112 ), whereby an outer edge portion of the confirmation ring (48; 112) is gripped between the fastening element (40) and the base body (12) and thereby deformed so that the outer edge portion of the confirmation ring (48; 112) is exposed to the vicinity of the fastening element (40; 106, 110), characterized in that additionally at least one protrusion (54a, 54b; 116) is provided on the outer edge portion of the confirmation ring (48; 112), the protrusion (54a, 54b; 116) protruding outward from the outer edge portion of the confirmation ring (48; 112) in a radial direction of the confirmation ring (48; 112) when the outer edge portion of the confirmation ring (48; 112) is deformed by the fastening of the fastening element (40).The pipe coupling according to claim 1, characterized in that the protrusion (54a, 54b; 116) extends from the outer edge portion of the confirmation ring (48; 112) substantially parallel to an axial direction of the confirmation member (48; 112) when the outer edge portion of the confirmation ring (48; 112) is not deformed.The pipe coupling according to claim 1 or 2, characterized in that the outer edge portion of the confirmation ring (48; 112) comprises an inclined portion (52) inclined relative to a flat portion (50) abutting the base body (12; 102), the inclined portion (52) being arranged substantially coplanar with the flat portion (50) upon pressing by the fastening element (40; 106, 110).The pipe coupling according to claim 3, characterized in that the inclined portion (52) is divided by a plurality of slits (58) which are respectively spaced at equal intervals in a circumferential direction of the outer edge portion of the lock ring (48; 112).The pipe coupling according to any one of the preceding claims, characterized in that the locking ring (48; 112) is annularly formed from an elastically deformable material.

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