Pipe connectors

Abstract

A pipe connector (2, 2A, 2B) with a connector body (30, 50) having a pipe connection opening (31, 31a, 31b) which has a retaining ring (35) for holding an outer circumferential surface of a pipe (8) that can be arranged in the pipe connection opening, a cylindrical release element (36) for releasing the retaining ring to stop holding, a cylindrical metallic connector guide (37) which guides the release element, and a seal (34) for sealing between an inner circumferential surface of the pipe connection opening and the outer circumferential surface of the pipe, wherein the connector guide has a barb (37e) on its outer circumferential surface which prevents separation and is pressed into the pipe connection opening, and wherein the inner circumferential surface of the pipe connection opening has several contact walls (42) which each have an inner wall surface (42a) in contact with the outer circumferential surface of the connector guide, wherein the contact walls are arranged at equal angular intervals around an axis (L) of the pipe connection opening and extend along the axis, and wherein the barb engages the contact walls.

Description

Technical field

[0001] The present invention relates to pipe connectors and in particular to pipe connectors for a hydraulic device. State of the art

[0002] Pipe connectors for attachment to hydraulic devices, such as a solenoid valve and a hydraulic cylinder, are known and described, for example, in PTL 1 and PTL 2.

[0003] This type of pipe connector typically comprises a synthetic resin (plastic) connector body for attachment to the hydraulic device, which has a circular pipe connection opening for connection to a line pipe, a metallic retaining ring for holding an outer circumferential surface of the pipe or hose, a release element for releasing the retaining ring to stop holding the pipe or hose, a cylindrical metallic connecting guide for guiding the release element, and a seal for sealing between an inner circumferential surface of the pipe connection opening and the outer circumferential surface of the pipe, so that the pipe connection opening accommodates the retaining ring, the release element, the connecting guide, and the seal.

[0004] The connecting guide is attached to the pipe connection opening by press-fitting. The connecting guide has an annular barb (locking hook) on its outer circumferential surface to engage the inner circumferential surface of the pipe connection opening, preventing the connecting guide from separating from the opening. The barb has an outer diameter that is slightly larger than the inner diameter of the pipe connection opening. Consequently, the connecting guide offers considerable resistance when pressed into the pipe connection opening. This makes installation difficult. In particular, the connector body, which is made of a brittle plastic such as fiberglass-reinforced plastic, can break and cannot be installed correctly because such a connector body is difficult to deform, thus enlarging the pipe connection opening. Cited documents Patent literature PTL 1: International Publication WO 2014 / 010 453 A1 PTL 2: Japanese unexamined patent disclosure JP H11 - 125 354 A Summary of the invention: Technical problem

[0005] It is a technical object of the present invention to propose a pipe connector with a connector body on plastic, which has a pipe connection opening for receiving a retaining ring for holding a pipe, a release element for releasing the retaining ring to stop holding, and a metallic connecting guide for guiding the release element, and which enables a simpler and more reliable press fastening of the connecting guide to the pipe connection opening than in the prior art. Solution to the task

[0006] To solve the problem described above, the present invention provides a pipe connector comprising a connector body with a pipe connection opening for receiving a retaining ring for holding an outer circumferential surface of a pipe (the term "pipe" in the sense of the present invention also includes hoses) arranged in the pipe connection opening, a cylindrical release element for releasing the retaining ring to stop holding it, a cylindrical metal connector guide which guides the release element, and a seal (packing) for sealing between an inner circumferential surface of the pipe connection opening and the outer circumferential surface of the pipe. The connector guide has a barb on its outer circumferential surface that prevents separation and is pressed into the pipe connection opening.The inner circumferential surface of the pipe connection opening comprises several contact walls, each having an inner wall surface that is in contact with the outer circumferential surface of the connector guide, wherein the contact walls are arranged at equal angular intervals around an axis of the pipe connection opening and extend along the axis, and wherein the barb engages in (captures) the contact walls.

[0007] According to the present invention, the pipe connection opening preferably has a non-circular (non-round) first opening section with the contact walls and a circular second opening section which is continuously connected to the first opening section, wherein the first opening section has a length along the axis that is less than that of the connector guide and that is greater than a distance from a proximal end of the connector guide to the barb, wherein the connector guide is pressed into the pipe connection opening such that a distal end of the connector guide is inserted into the second opening section and the barb is inserted into the first opening section, and wherein the seal is received in the second opening section.

[0008] In this case, an imaginary cylindrical surface, located inside and in contact with all contact walls, has a diameter equal to that of the second opening section. The inner wall surfaces of the contact walls can be flat surfaces touching the imaginary cylindrical surface, or they can be concave surfaces corresponding to portions of the imaginary cylindrical surface.

[0009] In the present invention, a recess is preferably provided between adjacent contact walls, wherein the recess serves as a relief which prevents the barb from engaging on a section other than the contact walls, and also as a relief which allows deformation of the connector guide on a section other than the inner wall surfaces when a force is applied thereto by the contact walls, and wherein the contact walls are four contact walls which are provided at 90° intervals.

[0010] In one embodiment of the present invention, the connector body comprises a cylindrical section with a diameter greater than the width of the connector body, and the cylindrical section has the pipe connection opening therein. The cylindrical section has flattened portions arranged on diametrically opposite sides, the flattened portions forming flat surfaces so that the sides are flush with the sides of the connector body, and the flattened portions being arranged between two adjacent contact walls.

[0011] The present invention also provides a solenoid valve with a pipe connector, which has a cylindrical section with flattened parts on the sides. The solenoid valve comprises a main valve section with a valve mechanism that switches between passages and a solenoid actuating section that drives the valve mechanism. The main valve section comprises a rectangular, cube-shaped (cubic) valve body in which the valve mechanism is provided, the valve body having a width equal to that of the connector body, and the connector body being attached to a terminal surface of the valve body. Advantageous effects of the invention

[0012] According to the present invention, the connector guide is pressed into the pipe connection opening while in contact with the contact walls. In this case, the resistance to pressing is significantly lower than when the connector guide is pressed into the pipe connection opening while the entire outer circumferential surface of the connector guide is in contact with the entire inner circumferential surface of the pipe connection opening. This facilitates the uniform pressing in of the connector guide.

[0013] During the insertion of the connector guide, a force exerted by the guide on the walls of the pipe connection opening is absorbed primarily through compression of the contact walls. Additionally, a force exerted by the contact walls on the connector guide is absorbed by slight outward deformation of the guide at points between adjacent contact walls. This synergy between these force-absorption effects reduces the likelihood of connector body deformation. If the connector body is made of a rigid, easily stretchable plastic, the probability of breakage due to deformation is further reduced. Brief description of the drawings Fig. Figure 1 is a perspective view of a solenoid valve with a pipe connector attached to it according to a first embodiment. Fig. 2 is a top view of Fig. 1. Fig. Figure 3 is a section through a significant part of the solenoid valve according to Fig. 1. Fig. 4 is a section through the pipe connector according to Fig. 5 along line IV-IV and shows connector parts and a seal that has been removed from one of the pipe connection openings. Fig. 5 is a top view of the pipe connector according to Fig. 4. Fig. Figure 6 is a section through part of the pipe connector according to Fig. 4 along line VI-VI. Fig. Figure 7 is a perspective exploded view of the connector parts and the seal that are accommodated in the pipe connector opening. Fig. Figure 8 is an enlarged front view of the lower pipe connection opening in Fig. 5. Fig. Figure 9 is a section through a pipe connector according to a second embodiment. Fig. Figure 10 is a section through an essential part of a pipe connector according to a third embodiment. Fig. Figure 11 is an exploded view of Fig. 10. Fig. Figure 12 is an enlarged front view of a pipe connection opening in Fig. 11. Description of embodiments

[0014] The Fig. Figures 1 to 3 show an electromagnetic valve 1, serving as an example of a hydraulic device, with a pipe connector 2 attached thereto according to the present invention. The electromagnetic valve 1 comprises a main valve section 3 with a valve mechanism that switches between fluid passages, and an electromagnet actuating section 4 that drives the valve mechanism. As shown in Fig. As shown in Figure 2, another solenoid valve 1A with the same construction as solenoid valve 1 can be connected directly to solenoid valve 1 in a series arrangement side by side, so that the assembled valves can be used. Since such a design of solenoid valve 1 is known (see, for example, the Japanese unexamined patent disclosure JP 2005-308122 A), the essential components and operations of the valve are only briefly described here. In the present embodiment, the fluid to be used is air.

[0015] As can be seen from Fig. As shown in Figure 3, the main valve section 3 of the solenoid valve 1 comprises a rectangular, cube-shaped (cubic) valve body 6 in which the valve mechanism is provided. The valve body 6 comprises a first block 6a in which the valve mechanism described above is provided, a second block 6b which serves as a distributor, and a third block 6c which serves as a piston box, such that these blocks are combined with one another. The valve body 6 has a longitudinally elongated rectangular shape when viewed from the front or the side, at which a first end 7a of the valve body 6 is located. The valve body 6 has right and left sides 6d, which are essentially flat surfaces.

[0016] In the first block 6a, a valve opening 10 extends from the first end 7a to a second end 7b opposite the first end 7a. A piston 11 (piston slide) is slidably mounted in the valve opening 10. A first piston 12 with a large diameter and a second piston 13 with a small diameter, which receives control air for the movement of the piston 11, are arranged at the first and second ends of the piston 11, respectively.

[0017] Furthermore, the valve opening 10 communicates with a single inlet opening 14, a first outlet opening 15a, a second outlet opening 15b, a first outlet opening 16a, and a second outlet opening 16b. The inlet opening 14 communicates with an inlet port 17 located in the second block 6b. The first outlet opening 15a and the second outlet opening 15b communicate with an outlet port 18 located in the second block 6b. The first outlet opening 16a and the second outlet opening 16b communicate with a first outlet port 19a and a second outlet port 19b, respectively, which open to the first end 7a of the first block 6a or the valve body 6. Therefore, the first end 7a is a connection surface of the valve body 6. The pipe connector 2, which is a quick connector, is attached to the connection surface 7a.

[0018] The electromagnetic actuating section 4 comprises a pilot or control body 22 connected to the second end 7a of the valve body 6, a three-way control solenoid valve 23 attached to the control body 22, and a control supply port 24 located in the control body 22. The control supply port 24 communicates with a first piston chamber 12a on the rear side of the first piston 12 via the control solenoid valve 23 and also continuously communicates with a second piston chamber 13a on the rear side of the second piston 13 via a control passage (not shown).

[0019] When the control solenoid valve 23 is not switched on, the first piston chamber 12a is open to the environment via the control solenoid valve 23. Thus, the piston 11, pressed by the second piston 13, assumes a first switching position, as described in Fig. Figure 3 shows that the supply port 14 communicates with the second outlet port 16b, the first outlet port 16a communicates with the first exhaust port 15a, air from the supply port 17 is discharged from the second outlet port 19b to a rod-side pressure chamber 26b of a pneumatic cylinder 25 through a plastic tube 8 connected to the tube connector 2, and air discharged from a head-side pressure chamber 26a of the pneumatic cylinder 24 flows into the first outlet port 19a through another tube 8 and the tube connector 2 and is then discharged from the exhaust port 18 through the first outlet port 16a and the first exhaust port 15a. Thus, a piston 27 and a rod 28 of the pneumatic cylinder 25 assume a retracted position.

[0020] When the control solenoid valve 23 is switched on, control air is supplied to the first piston chamber 12a via the control solenoid valve 23. This causes the piston 11 to be pressed by the first large-diameter piston 12 and to assume a second switching position, which corresponds to the one in Fig. The position shown in Figure 3 is opposite to that shown. The supply port 14 communicates with the first outlet port 16a, the second outlet port 16b communicates with the second outlet port 15b, air from the supply port 17 is discharged to the head-side pressure chamber 26a of the pneumatic cylinder 25 through the first outlet port 19a, and air discharged from the rod-side pressure chamber 26b of the pneumatic cylinder 25 flows through the second outlet port 19b, the second outlet port 16b, and the second outlet port 15b, and is then discharged through the outlet port 18. Thus, the piston 27 and the rod 28 of the pneumatic cylinder 25 move forward.

[0021] Now, pipe connector 2 will be described. As can be seen from the Fig. 4 and Fig. As 5 results, the pipe connector 2 comprises a connector body 30 made of synthetic resin (plastic). Similar to the valve body 6 of the solenoid valve 1, the connector body 30, viewed from the front or the side where its front surface is arranged with two pipe connection openings 31a and 31b, has a longitudinally elongated rectangular shape. The connector body 30 has right and left sides 30a, which are flat surfaces. The connector body 30 has a width W1 (see Fig. 2), which is essentially equal to the width W2 of the valve body 6. For example, polybutylene terephthalate (PBT) is a suitable plastic for the connector body 30.

[0022] The connector body 30 comprises two vertically arranged cylindrical sections 32a and 32b on its front surface. Pipe connection openings 31a and 31b are formed in the cylindrical sections 32a and 32b, respectively. The first pipe connection opening 31a in the upper cylindrical section 32a communicates with the first outlet port 19a of the valve body 6 through a through-opening 33a. The second pipe connection opening 31b in the lower cylindrical section 32b communicates with the second outlet port 19b of the valve body 6 through a through-opening 33b. Each pipe connection opening 31a and 31b accommodates several connector parts and a seal 34.The connector components comprise a retaining ring 35 for holding an outer circumferential surface of the pipe 8, which is arranged in the pipe connection opening 31a or 31b; a release element 36, which can be pressed to release the retaining ring 35 so that it stops holding; and a connector guide 37, which guides the release element 36. The seal 34 seals between an inner circumferential surface of the pipe connection opening 31 and the outer circumferential surface of the pipe 8.

[0023] The first pipe connection opening 31a and the second pipe connection opening 31b have the same construction, including the connector parts and the seal 34, and the first cylindrical section 32a and the second cylindrical section 32b have essentially the same shape. Therefore, in the following description, the first pipe connection opening 31a and the second pipe connection opening 31b are collectively referred to as "pipe connection openings 31" when they do not need to be distinguished from one another. Similarly, the first cylindrical section 32a and the second cylindrical section 32b are collectively referred to as "cylindrical sections 32" when they do not need to be distinguished from one another. The same applies to the through openings 33a and 33b.

[0024] The cylindrical sections 32 of the connector body 30 have an outer diameter that is slightly larger than the width W1 of the connector body 30. This is to prevent the cylindrical sections 32 from coming into contact with each other when the multiple solenoid valves 1 and 1A are connected together, as described in Fig. As shown in Figure 2, flattened parts 38, which provide flat surfaces, are provided on diametrically opposite sides of the cylindrical sections 32, or on the opposite sides facing in the direction along the width W1 of the connector body 30, such that the opposite sides are flush with the sides of the connector body 30, as shown in the Fig. 1 and Fig. 5 is shown.

[0025] As can be seen from the Fig. 4, Fig. 6 and Fig. As shown in Figure 7, the retaining ring 35, which is formed by stamping a thin stainless steel metal plate, comprises a cylindrical part 35a adjacent to a proximal end of the retaining ring 35 and a retaining part 35b adjacent to its distal end. The retaining part 35b tapers towards the distal end, so that its diameter gradually decreases, and has an edge 35c at the distal end to hold the outer circumferential surface of the tube 8. The retaining ring 35 has several first slots 35d extending along the axis L of the tube connection opening 31 and arranged at regular intervals, such that the first slots 35d extend from the distal end of the retaining part 35b to a position adjacent to the proximal end of the cylindrical part 35a.Furthermore, the retaining ring 35 has several second slots 35e, which are arranged at regular intervals such that each second slot 35e is arranged between the adjacent first slots 35d and extends from the proximal end of the cylindrical part 35a to a position near the retaining part 35b.

[0026] The release element 36, which is a cylindrical plastic element, is designed such that a distal end of the release element 38 is located near an inner surface of the retaining part 35b of the retaining ring 35, and that a proximal end of the release element 36 projects from the pipe connection opening 31. At its proximal end, the release element 36 comprises a flange 36a that extends radially outward. The flange 36a has an outer diameter that is larger than the inner diameter of the pipe connection opening 31 and smaller than the outer diameter of the cylindrical section 32. The release element 36 has several slots 36b arranged adjacent to its distal end at regular intervals. On its outer circumferential surface, the release element 36 includes an annular projection 36c with a continuous circular inclined surface 36d as its front face.

[0027] As in Fig. As shown in Figure 6, if the release element 36 is not pressed into the pipe connection opening 31, the inclined surface 36d of the annular projection 36c is held and positioned by the proximal end of the retaining ring 35. When the flange 36a is pressed into the pipe connection opening 31 with a finger, the annular projection 36c slides on an inner circumferential surface of the retaining ring 35, and the distal end of the release element 36 expands the retaining part 35b away from the pipe 8. In this state, the pipe 8 can be removed from the pipe connector 2.

[0028] The connecting guide 37 limits the movement of the retaining ring 35 along the axis L and also guides the movement of the release element 36 along the axis L. The connecting guide 37 is a hollow cylinder formed by stamping a metal plate, for example made of stainless steel, and is pressed into the pipe connection opening 31 and fixed there. Specifically, the connecting guide 37 comprises a guide base body part 37a, which is arranged at a proximal end of the connecting guide 37 and has the structure of a single cylinder (single-walled construction), and a distal guide end part 37b with the structure of a double cylinder (double-walled construction).The distal guide end part 37b comprises an inner cylindrical part 37c extending continuously from the guide base body part 37a, and an outer cylindrical part 37d formed by folding a distal end section of the inner cylindrical part 37c onto an outer surface of the inner cylindrical part 37. The outer cylindrical part 37d includes at its end an annular barb 37e (latch) angled obliquely towards the proximal end of the connector guide 37. The barb 37e engages or latches into the inner wall surfaces 42a of contact walls 42 arranged in the pipe connection opening 31.

[0029] The barb 37e is divided into several arc-shaped segments by several cuts 37f, which are arranged at regular intervals. With this design, the barb 37e can be easily elastically deformed, so that the barb 37e reduces its diameter when the connector guide 37 is pressed into the pipe connection opening 31. This facilitates the pressing in of the connector guide 37.

[0030] The inner cylindrical part 37c of the distal guide end part 37b has an inner diameter that is smaller than that of the guide base part 37a. The outer cylindrical part 37d has an outer diameter that is approximately equal to that of the guide base part 37a. The guide base part 37a comprises at its proximal end an annular guide section 37g, the end of which is turned inwards and curved so that it has a substantially circular cross-section. The annular guide section 37g is intended to contact the outer circumferential surface of the release element 36. During pressing, the release element 36 is guided by the annular guide section 37g.

[0031] Now the pipe connection openings 31 are described. As can be seen from the Fig. 4 to 6 and 8, each pipe connection opening 31 comprises a non-circular first hole section 41a, into which the connector guide 37 is pressed, a circular second hole section 41b, which receives the seal (packing) 34, and a circular third hole section 41c, arranged in this order in one direction from an inlet of the opening to the through-opening 33. The third opening section 41c has a diameter smaller than that of the second opening section 41b and is dimensioned such that a distal end of the pipe 8 is inserted substantially snugly.

[0032] The first hole section 41a has a length (depth) X along the axis L that is smaller than the length (depth) Y along the axis L of the second hole section 41b. Furthermore, the length X is slightly smaller than the length Z of the connector guide 37, but larger than a distance Zo from the proximal end of the connector guide 37 to the barb 37e.

[0033] The first hole section 41a has an inner circumferential surface that encompasses the contact walls 42, which project towards the axis of the pipe connection opening 31, such that the contact walls 42, extending along the axis L, are spaced at equal angular intervals around the axis L of the pipe connection opening 31. The inner wall surfaces 42a of the contact walls 42 are in contact with the outer circumferential surface of the connector guide 37. In one illustrated example, four contact walls 42 are provided at 90° intervals. Each of the flattened portions 38 of the sides of the cylindrical section 42 is provided between the inner wall surfaces 42a of the two adjacent contact walls 42. Specifically, the flattened portion 38 is arranged between two planes m that connect the ends (adjacent ends) of the inner wall surfaces 42a of the two adjacent contact walls 42 to the axis L of the pipe connection opening 31.

[0034] The inner wall surface 42a of each contact wall 42 is a concave surface curved outwards in a radial direction of the pipe connection opening 31. The concave surface forms part of an imaginary cylindrical surface S that runs coaxially to the pipe connection opening 31. In the example shown, the imaginary cylindrical surface S has the same diameter as the second hole section 41b. Accordingly, the concave surface has the same radius of curvature as the second hole section 41b. Thus, the inner wall surface 42a of the contact wall 42 touches an inner circumferential surface of the second hole section 41b smoothly without a shoulder (step).

[0035] Furthermore, the diameter of the imaginary cylindrical surface S is the same as or slightly larger than the outer diameter of the guide base part 37a of the connector guide 37 and smaller than the diameter of the barb 37e.

[0036] Regarding the shape of a cross-section of the contact wall 42 perpendicular to the axis L, the cross-section gradually increases in width in one direction from the inner wall surface 42a to a proximal end of the contact wall 42. The side wall surfaces 42b to the right and left of the contact wall 42 are concavely curved.

[0037] Furthermore, a recess 43, curved to correspond to a portion of a cylindrical surface, is provided between the adjacent contact walls 42. The recess 43 partially defines the side wall surfaces 42b of the contact walls 42. The recess 43 has a radius of curvature smaller than that of the pipe connection opening 31 or the second hole section 41b. The recess 43 is deepest at a midpoint between the adjacent contact walls 42 where the barb 37e of the connector guide 37 is not in contact with the recess 43. In other words, a circle circumscribing the deepest parts of all recesses 43 has a larger diameter than the outer diameter of the barb 37e. Therefore, all recesses 43 act as a relief, preventing the barb 37e from engaging any section other than the contact walls 42.

[0038] Each contact wall 42 also has an end wall surface 42c facing the inlet of the pipe connection opening 31. The end wall surface 42c slopes gradually down to the inner wall surface 42a at the rear of the pipe connection opening 31 or the second hole section 41b.

[0039] For example, the contact walls 42 can be shaped as follows. The first hole section 41a is formed as a circular hole corresponding to the imaginary cylindrical surface S. Then, a drill D is used to cut an inner circumferential surface of the hole such that four recesses 43 are provided at 90° intervals. Thus, the contact walls 42 can be formed between the adjacent recesses 43.

[0040] When the connector guide 37 is pressed into the pipe connection opening formed as described above, the sloping end wall surfaces 42c of the contact walls 42 guide the connector guide 37 to a position where it is coaxial with the pipe connection opening 31. The connector guide 37 is then pressed into the first hole section 41a of the pipe connection opening 31. At this time, the outer circumferential surface of the connector guide 37, in particular the barb 37e, is brought into close contact with the inner wall surfaces 42a of the contact walls 42. Accordingly, the barb 37e is elastically deformed, reducing its diameter, while the contact walls 42 are compressed by the barb 37e in a direction in which the diameter of the imaginary cylindrical surface S increases.As it is guided through the inner wall surfaces 42a, the connector guide 37 is pressed into a position where the proximal end of the annular guide section 37g coincides with a recessed end of the pipe connection opening 37. At this position, the barb 37e engages the inner wall surfaces 42a of the respective contact walls 42 and is thus fixed in place. In this state, the distal guide part 37b is partially positioned in the second hole section 41b.

[0041] To facilitate understanding, it shows Fig. 6 exaggerates the digging and locking of the barb 37e into the inner wall surfaces 42a of the contact walls 42. In fact, the extent to which the barb 37e engages in the inner wall surfaces 42a of the contact walls 42 is less than shown.

[0042] Since the outer circumferential surface of the connector guide 37 is in contact with the multiple contact walls 42, the connector guide 37 is pressed into the pipe connection opening 31, being in partial contact with the inner circumferential surface of the pipe connection opening 31. Therefore, the resistance to pressing in is significantly lower in this case than when the connector guide 37 is pressed into the pipe connection opening 31 with its entire outer circumferential surface in contact with the inner circumferential surface of the pipe connection opening 31. This facilitates the smooth pressing in of the connector guide 37.

[0043] Since the inner wall surfaces 42a, which are concave, of the contact walls 42 are in close contact with the outer circumferential surface of the connector guide 37, the contact walls 42 also support the connector guide 37 continuously during and after pressing.

[0044] While the connector guide 37 is being pressed in, the cylindrical section 32 of the connector body 30, which is made of plastic, is also subjected to a force acting in a direction in which the diameter of the cylindrical section 32 can increase. This force is primarily absorbed by compression of the contact walls 42. A compressive force generated by the contact walls 42 and acting inwards on the connector guide 37 (towards the axis L) is absorbed by slight, outward-directed, elastic deformation of the connector guide 37 at the recesses 43. This synergy between these force-absorption effects reduces the force acting on the connector body 30. As a result, the cylindrical section 32 is subject to less deformation overall. If the cylindrical section 32 is slightly deformed, the deformed portion can encompass the contact walls 42 and their surrounding area.The entire cylindrical section 32 is unlikely to deform significantly and uniformly. Therefore, if the connector body 30 is made of a glass fiber reinforced plastic that is stiff and prone to elongation, the connector guide 37 can be pressed into the pipe connection opening 31, while preventing breakage of the cylindrical section 32 due to the increase in its overall diameter.

[0045] If the connector guide 37 is elastically deformed at the recesses 43, which each serve as relief in the manner described above, the deformation will not interfere with the attachment / removal of the tube 8 because the size of the deformation is small.

[0046] Even in a case where all the flattened parts 38 of the sides of each cylindrical section 32 lead to a reduction in the thickness of the cylindrical sections 32 on that part, as in the first embodiment described above, the flattened part 38 arranged between the adjacent contact walls 42 avoids a deformation of the cylindrical section 32 on the flattened part 38, thus preventing the cylindrical section 32 from breaking.

[0047] If the outer diameter of the cylindrical section 32 is equal to or smaller than the width of the connector body, the flattened parts 38 need not be provided.

[0048] In the pipe connector 2 according to the first embodiment described above, four contact walls 42 are provided in each pipe connection opening 31. However, the number of contact walls 42 can also be two, three, five or more.

[0049] Even though the pipe connector 2 according to the first embodiment described above has the connector body 30 with the two pipe connection openings 31, the present invention is also applicable to a pipe connector with a connector body 50 that has a single pipe connection opening 31, such as a pipe connector 2A according to a second embodiment, which is described in Fig. 9 is shown.

[0050] The pipe connector 2A according to the second embodiment is of a type used in direct connection with a port of a hydraulic device. The connector body 50 comprises a mounting section 51, which has an external thread 51a on its outer circumferential surface for screwing into a threaded opening of the port, and a cylindrical section 52 with a pipe connection opening 31. The pipe connection opening 31 is designed similarly to the pipe connection opening 31 in the first embodiment described above. The pipe connection opening 31 accommodates connector parts and a seal (packing) 34, similar to the pipe connector 2 according to the first embodiment.Therefore, in the pipe connector 2A according to the second embodiment, the same components and parts as in the pipe connector 2 according to the first embodiment are designated with the same reference numerals, and a description of these components and parts is omitted.

[0051] In the pipe connector 2 according to the first embodiment and the pipe connector 2A according to the second embodiment, the inner wall surface 42a of each contact wall 42 is concave. The inner wall surface 42a can also be a flat surface that touches the imaginary cylindrical surface S.

[0052] The Fig. Figures 10 to 12 represent a third embodiment of a different pipe connector in which the inner wall surface 42a of each contact wall 42 is a flat surface. A pipe connector 2B according to the third embodiment differs from the pipe connector 2 or 2A according to the first or second embodiment only with respect to the shape of the pipe connection opening 31, in particular the first hole section 41a. The remainder of the configuration of the pipe connector 2B is essentially the same as that of the pipe connector 2 or 2A according to the first or second embodiment. Accordingly, the following description will focus on the shape of the first hole section 41a. For the remainder of the configuration, the same components and parts as in the first or second embodiment are designated with the same reference numerals, and a description of these components and parts is omitted.

[0053] In the 2D pipe connector, a pipe connection opening 31 comprises a non-circular first hole section 41a, a circular second hole section 41b, and a circular third hole section 41c. The first hole section 41a has four contact walls 42 spaced at 90° intervals around the axis L, and arcuately curved recesses 43, each located between adjacent contact walls 42. Each contact wall 42 has an inner wall surface 42a, which is a flat surface touching the imaginary cylindrical surface S and having the same diameter as the second hole section 41b. The inner wall surface 42a linearly connects an end of the recess 43 located on a first side of the contact wall 42 to an end of the recess 43 located on a second side of the contact wall 42.In other words, the inner wall surface 42a is a single flat surface extending across the width of the contact wall 42.

[0054] The depression 43 corresponds to part of a cylindrical surface and forms part of an imaginary cylindrical surface T, which is arranged coaxially to the imaginary cylindrical surface S and has a larger diameter than the imaginary cylindrical surface S.

[0055] In the pipe connector 2B according to the third embodiment, a connector guide 37 is pressed into the pipe connection opening 31 in a similar manner to the pipe connectors 2 and 2A according to the first and second embodiments. Here, the inner wall surface 42a of each contact wall 42 is in contact with the connector guide 37 at a position where the inner wall surface 42a touches the imaginary cylindrical surface S, or at the midpoint of the width of the inner wall surface 42a.

[0056] The inner wall surface 42a of each contact wall 42 does not necessarily have to extend over the width of the contact wall 42. It is only required that the inner wall surface 42a be designed as a part of the contact wall 42 that is to come into contact with the connector guide 37. In this case, each section (section corresponding to the side wall surface 42b in Fig. 8), which connects a side edge of the inner wall surface 42a, which is formed as the section described above, with a side edge of the recess 43, run linearly obliquely relative to the inner wall surface 42a.

[0057] Furthermore, the contact wall 42 can have a sloping end wall surface similar to the end wall surface 42c of the contact wall 42 in the pipe connector 2 according to the first embodiment, so that the end wall surface gradually slopes down to the inner wall surface 42a towards the rear of the pipe connection opening 31.

[0058] The present invention is also applicable to a pipe connector (not shown) for connecting pipes, namely a pipe connector with a connector body that has pipe connection openings at opposite ends. Reference symbol list 1 solenoid valve 2, 2A, 2B pipe connectors 3 Main valve section 4 Electromagnetic actuation section 6 valve bodies 7a Connection area 8 pipe (hose) 30, 50 connector bodies 31, 31a, 31b Pipe connection opening 32a, 32b, 52 Cylindrical section 34 Seal (Pack) 35 retaining ring 36 Release element 37 Connector guide 37e Barb 38 Flattened part 41a First hole section 41b Second Hole Section 42 contact wall 42a Inner wall surface 42b Side wall surface 42c End wall area 43 In-depth study S Imaginary cylindrical surface L axis W1 Width of the connector body W2 Width of the valve body X Length of the first hole section Z Length of the connector guide Zo distance from the proximal end of the connector guide to the barb

Claims

[1] A pipe connector (2, 2A, 2B) with a connector body (30, 50) having a pipe connection opening (31, 31a, 31b) having a retaining ring (35) for holding an outer circumferential surface of a pipe (8) that can be arranged in the pipe connection opening, a cylindrical release element (36) for releasing the retaining ring to stop holding, a cylindrical metallic connector guide (37) which guides the release element, and a seal (34) for sealing between an inner circumferential surface of the pipe connection opening and the outer circumferential surface of the pipe, wherein the connector guide has a barb (37e) on its outer circumferential surface which prevents separation and is pressed into the pipe connection opening, and wherein the inner circumferential surface of the pipe connection opening has several contact walls (42) which each have an inner wall surface (42a) in contact with the outer circumferential surface of the connector guide, wherein the contact walls are arranged at equal angular intervals around an axis (L) of the pipe connection opening and extend along the axis, and wherein the barb engages the contact walls. [2] The pipe connector according to claim 1, wherein the pipe connection opening has a non-circular first hole section (41a) with the contact walls and a circular second hole section (42b) extending continuously from the first hole section, wherein the first hole section has a length along the axis that is less than that of the connector guide and greater than a distance from a proximal end of the connector guide to the barb, wherein the connector guide is pressed into the pipe connection opening such that a distal end of the connector guide is inserted into the second hole section and the barb is inserted into the first hole section, and the seal is included in the second hole section. [3] The pipe connector according to claim 2, wherein an imaginary cylindrical surface (S) is arranged inside and in contact with each of the contact walls and has a diameter equal to that of the second hole section. [4] The pipe connector according to claim 3, wherein the inner wall surfaces of the contact walls are flat surfaces which touch the imaginary cylindrical surface. [5] The pipe connector according to claim 3, wherein the inner wall surfaces of the contact walls are concave surfaces corresponding to parts of the imaginary cylindrical surface. [6] The pipe connector according to claim 1, wherein a recess (43) is provided between adjacent contact walls and the recess serves as a relief that prevents the barb from engaging on sections other than the contact walls, and also as a relief that allows deformation of the connector guide on a section other than the inner wall surfaces when it experiences a force applied by the contact walls. [7] The pipe connector according to claim 1, wherein the contact walls are four contact walls arranged at 90° intervals. [8] The pipe connector according to claim 1, wherein the connector body has a cylindrical section (32a, 32b, 52) with a diameter greater than a width of the connector body, and wherein the pipe connection opening is formed in the cylindrical section, and wherein the cylindrical section has flattened parts arranged on diametrically opposite sides, wherein the flattened parts provide flat surfaces such that the sides are flush with sides of the connector body, and wherein the flat parts are each arranged between two adjacent contact walls. [9] An electromagnetic valve (1) with the pipe connector according to claim 8, wherein the electromagnetic valve comprises: a main valve section (3) with a valve mechanism that switches between passages, and an electromagnetic actuating section (4) that drives the valve mechanism, wherein the main valve section has a rectangular cube-shaped valve body (6) in which the valve mechanism is provided, wherein the valve body has a width equal to that of the connector body, and wherein the connector body is attached to a connecting surface (7a) of the valve body.

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