Crimping claw

Abstract

Provided is a crimping claw 14 capable of coupling a hose 12 and a hose joint fitting 10 with a coupling force as designed.　An inner peripheral surface 1402 of the crimping claw 14 is provided with an elongation prevention part 22A that increases a gripping force on an outer peripheral surface 1808 of a socket 18 and prevents elongation to an opening 2002 side of an annular space 20 in the axial direction of the socket 18 during crimping. The entire area of the inner peripheral surface 1402 of the crimping claw 14 is formed with a surface roughness of from Ra12.5S to Ra25S inclusive. Thus, the inner peripheral surface 1402 of the crimping claw 14 is formed to have high frictional resistance against the outer peripheral surface 1808 of the socket 18 when the inner peripheral surface 1402 of the crimping claw 14 is brought into pressure contact with the outer peripheral surface 1808 of the socket 18. The elongation prevention part 22A is constituted by the inner peripheral surface 1402 of the crimping claw 14 having such a surface roughness.

Description

Crimping claws

[0001] The present invention relates to a crimping claw for crimping a socket of a hose coupling.

[0002] The hose coupling comprises a nipple having a hose insertion portion, and a socket, one axial end of the socket is attached to the nipple's attachment recess, an annular space into which the hose is inserted is formed between the socket and the hose insertion portion, and the other axial end of the socket forms an opening through which the hose is inserted into the annular space. With the hose inserted into the annular space between the nipple and socket through the opening, the socket is crimped from its radial outside to its radial inside by multiple crimping claws, joining the hose coupling and the hose.

[0003] Japanese Patent Application Laid-Open No. 2016-8673

[0004] In this case, if the outer diameter of the socket after crimping is constant, the inner diameter of the socket will also be constant, and the hose and hose coupling should be able to be connected with the designed connecting force. However, in reality, during mass production, even if the outer diameter of the socket after crimping is constant, variations in the crimping condition of the hose occur, resulting in variations in the connecting force. To solve this problem, the inventors conducted extensive research and discovered that the variations in the crimping condition of the hose are caused by the socket stretching axially toward the opening of the annular space when the socket is crimped from the radially outer side to the radially inner side. That is, the inventors discovered that when the socket is crimped, the socket stretches axially toward the opening of the annular space and also stretches circumferentially. However, this circumferential stretch is extremely small compared to the axial stretch of the socket and can be ignored. Furthermore, the outer and inner peripheral portions of the socket stretch almost integrally in the axial direction of the socket. They discovered that suppressing this axial stretch of the socket suppresses the variations in the crimping condition of the hose. The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide a crimping claw that can connect a hose and a hose coupling with the designed connecting force.

[0005] In order to achieve the above object, one embodiment of the present invention provides a hose coupling fitting with a plurality of crimping claws arranged at intervals around the circumferential surface of a socket radially outward of the outer circumferential surface of the socket when a hose is inserted into the annular space between a nipple and a socket, the crimping claws moving radially inward of the socket to crimp the socket, the locations where the crimping claws contact the outer circumferential surface of the socket are formed by inner circumferential surfaces consisting of cylindrical surfaces that match the outer circumferential surface of the socket after crimping, and the inner circumferential surfaces of the crimping claws are provided with elongation suppressing portions that increase the gripping force on the outer circumferential surface of the socket and suppress elongation of the outer circumferential portion of the socket in the axial direction of the socket when the socket is crimped.Furthermore, one embodiment of the present invention is characterized in that the inner circumferential surfaces of the crimping claws are formed with a surface roughness of Ra 12.5 or more and Ra 25 or less, and the elongation suppressing portion is formed by the inner circumferential surface of the crimping claws having the surface roughness. Furthermore, one embodiment of the present invention provides a hose coupling fitting having a plurality of crimping claws arranged radially outward of the outer peripheral surface of the socket at intervals around the outer peripheral surface when a hose is inserted into the annular space between a nipple and a socket, the crimping claws crimping the socket by moving radially inward of the socket, one axial end of the socket is connected to the nipple so as to be immovable in the axial direction, and the other axial end of the socket forms an opening of the annular space, the portion of the crimping claw that abuts the outer peripheral surface of the socket is formed by an inner circumferential surface consisting of a cylindrical surface that matches the outer peripheral surface of the socket after crimping, and the inner circumferential surface of the crimping claw is provided with an elongation suppressing portion that suppresses elongation of the outer peripheral portion of the socket in the axial direction when the socket is crimped, the elongation suppressing portion is formed on the inner circumferential surface of the crimping claw that abuts against a portion of the outer peripheral surface of the socket near the opening, the portion of the outer peripheral portion of the socket that expands in the axial direction when crimped is filled, and the filled portion is configured with a plurality of grooves that suppress elongation of the outer peripheral portion of the socket.In one embodiment of the present invention, the groove extends in a direction intersecting the axial direction of the inner circumferential surface, when viewed from a direction perpendicular to the axial direction of the inner circumferential surface, and the width of the groove in the direction perpendicular to the extending direction of the groove is 0.3 mm to 1.0 mm, and the depth of the groove from the inner circumferential surface is 0.3 mm to 1.0 mm. In another embodiment of the present invention, the crimping claw has a pair of side surfaces rising from both circumferential sides of the inner circumferential surface, the groove penetrates between the pair of side surfaces, and both ends of the groove in the extending direction are open at the pair of side surfaces. In another embodiment of the present invention, the groove includes a pair of groove surfaces facing each other, and a point where the pair of groove surfaces intersects with the inner circumferential surface is formed as a corner. In another embodiment of the present invention, the groove is provided in a plurality of grooves spaced apart in the axial direction of the inner circumferential surface. In another embodiment of the present invention, the groove is formed as an X-shaped groove where two grooves intersect.Further, one embodiment of the present invention provides a hose coupling fitting having a plurality of crimping claws arranged at intervals in the circumferential direction of the outer circumferential surface of a socket on the radially outer side of the outer circumferential surface of the socket when a hose is inserted into an annular space between a nipple and a socket, the crimping claws moving in the radially inner direction of the socket to crimp the socket, one axial end of the socket is connected to the nipple so as to be immovable in the axial direction, the other axial end of the socket forms an opening of the annular space, and the portion where the crimping claws come into contact with the outer circumferential surface of the socket is formed by an inner circumferential surface consisting of a cylindrical surface that matches the outer circumferential surface of the socket after crimping, a first elongation suppressing portion that suppresses elongation of the outer periphery of the socket in the axial direction, the first elongation suppressing portion being formed on the inner periphery of the crimping claw that abuts against the outer periphery of the socket near the opening, and the first elongation suppressing portion is composed of a plurality of grooves that fill the portions of the outer periphery of the socket that expand in the axial direction during crimping, and these filled portions suppress elongation of the outer periphery of the socket, and a second elongation suppressing portion is provided on the remaining portion of the inner periphery of the crimping claw that increases the grip force on the outer periphery of the socket and suppresses elongation of the outer periphery of the socket in the axial direction when the socket is crimped.

[0006] According to one embodiment of the present invention, an elongation suppressing portion is provided that increases the gripping force on the outer peripheral surface of the socket and suppresses elongation of the outer peripheral portion of the socket in the axial direction of the socket, thereby suppressing elongation of the outer peripheral portion of the socket during crimping. Also, according to one embodiment of the present invention, when the outer peripheral portion of the socket expands in the axial direction during crimping, the expanded portion of the outer peripheral portion of the socket enters and fills the multiple grooves. The filled portions of the outer peripheral portion of the socket provide resistance when the socket tries to expand toward the opening, thereby suppressing elongation of the outer peripheral portion of the socket toward the opening during crimping. Also, according to one embodiment of the present invention, the portions of the outer peripheral portion of the socket that expand in the axial direction of the socket during crimping are filled in the inner peripheral surface of the crimping claws that abut against the portions of the outer peripheral surface of the socket near the opening, and these filled portions form multiple grooves that suppress elongation of the outer peripheral portion of the socket. The multiple grooves constitute a first elongation suppressing portion that suppresses elongation of the outer peripheral portion of the socket in the axial direction of the socket during crimping. Additionally, a second elongation suppressing portion is provided on the inner peripheral surface of the remaining clamping claw, which increases the gripping force on the outer peripheral surface of the socket and suppresses axial elongation of the outer peripheral portion of the socket when the socket is crimped. This suppresses elongation of the outer peripheral portion of the socket toward the opening when the socket is crimped. The inventors have discovered that the outer peripheral portion and inner peripheral portion of the socket elongate in the axial direction of the socket almost integrally. Therefore, suppressing axial elongation of the outer peripheral portion of the socket can suppress axial elongation of the entire socket, including the outer peripheral portion and inner peripheral portion. This suppresses variation in the degree of crimping of the hose, which is advantageous for connecting the hose and the hose coupling with the designed connecting force.

[0007] 1A and 1B are explanatory views of the process of moving the crimping claws from the radially outer side to the radially inner side of the socket to crimp the socket, where (A) shows a state in which a hose is inserted into the annular space and the crimping claws are positioned apart radially outward of the outer peripheral surface of the socket, and (B) shows the state after crimping.

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[0008] Next, embodiments of the present invention will be described with reference to the drawings. (First Embodiment) As shown in Figures 1 and 2, a hose coupling fitting 10 and a hose 12 are connected by a plurality of crimping claws 14 of a crimping device. The hose coupling fitting 10 includes a nipple 16 and a socket 18. The nipple 16 has an equipment-side connection portion 1602 and a hose insertion portion 1604 that is inserted into the hose 12. The outer peripheral surface of the hose insertion portion 1604 is provided with an uneven portion 1606 to ensure reliable connection with the hose 12. The socket 18 has one axial end 1802 attached to the attachment recess 1608 of the nipple 16 and extends cylindrically radially outward of the hose insertion portion 1604. An annular space 20 into which the hose 12 is inserted is formed between the outer periphery of the hose insertion portion 1604 and the inner periphery of the socket 18, and the inside of the other axial end 1804 of the socket 18 forms an opening 2002 of the annular space 20 through which the hose 12 is inserted. The inner periphery of the socket 18 is provided with a plurality of circumferentially extending protrusions 1806 spaced apart in the axial direction to ensure reliable coupling with the hose 12, or alternatively, a plurality of circumferentially extending protrusions are provided in the axial direction of the inner periphery of the socket 18 at intervals. The socket 18 can be made of various conventionally known materials, such as S20C and S10C.

[0009] As shown in Fig. 2(A), a plurality of crimping claws 14 are arranged radially outward of the outer peripheral surface 1808 of the socket 18 of the hose coupling fitting 10 set in the crimping device, spaced apart in the circumferential direction of the outer peripheral surface 1808; in this embodiment, eight crimping claws 14 are arranged, and the eight crimping claws 14 simultaneously move radially inward of the socket 18 to crimp the socket 18. As shown in Fig. 1, the crimping claws 14 are formed with a length that is approximately equal to the length of the portion of the socket 18 to be crimped along the axial direction of the socket 18, or greater than the length of the socket 18. The portion where the crimping claws 14 come into contact with the outer peripheral surface 1808 of the socket 18 is formed by an inner peripheral surface 1402 that is a cylindrical surface that matches the outer peripheral surface 1808 of the socket 18 after crimping.

[0010] 3 , inner peripheral surfaces 1402 of crimping claws 14 are provided with elongation suppressing portions 22A that increase the gripping force with respect to outer peripheral surface 1808 of socket 18 and suppress elongation of socket 18 in the axial direction toward opening 2002 of annular space 20 during crimping. In this embodiment, the entire inner peripheral surfaces 1402 of crimping claws 14 are formed with a surface roughness of not less than Ra 12.5 and not more than Ra 25, thereby increasing the frictional resistance of inner peripheral surfaces 1402 of crimping claws 14 against outer peripheral surface 1808 of socket 18 when inner peripheral surfaces 1402 of crimping claws 14 are pressed against outer peripheral surface 1808 of socket 18. That is, elongation suppressing portion 22A is configured by inner peripheral surfaces 1402 of crimping claws 14 having a surface roughness that increases the frictional resistance of inner peripheral surfaces 1402 of crimping claws 14 against outer peripheral surface 1808 of socket 18 when inner peripheral surfaces 1402 of crimping claws 14 are pressed against outer peripheral surface 1808 of socket 18. Conventionally, inner peripheral surfaces 1402 of crimping claws 14 are subjected to cutting, grinding, and hardening processes, but inner peripheral surfaces 1402 with a surface roughness of Ra 12.5 or more and Ra 25 or less can be formed by omitting the grinding process after cutting, and inner peripheral surfaces 1402 with a surface roughness of Ra 12.5 or more and Ra 25 or less are formed by cutting marks made by a cutting tool such as a bit or drill. The crimping claws 14 can be made of various conventionally known materials such as SKD11, and the hardness of the inner circumferential surface 1402 including the elongation suppressing portion 22A is, for example, around HRC58.

[0011] If the surface roughness of the inner peripheral surface 1402 of the crimping claw 14 is less than Ra 12.5, for example, if grease on the worker's gloves gets on the inner peripheral surface 1402 of the crimping claw 14 and reduces the frictional resistance with the outer peripheral surface 1808 of the socket 18, or if the material of the socket 18 itself has varying physical properties, the gripping force that suppresses extension of the socket 18 in the axial direction toward the opening 2002 of the annular space 20 will decrease. On the other hand, if the surface roughness of the inner peripheral surface 1402 of the crimping claw 14 exceeds Ra 25, the appearance of the outer peripheral surface 1808 of the socket 18 after crimping will be poor, which is disadvantageous in terms of increasing the commercial value of the hose coupling fitting 10.

[0012] With the hose 12 inserted into the annular space 20, eight crimping claws 14 are arranged on the radially outer side of the socket 18, as shown in Figures 1(A) and 2(A), and these crimping claws 14 are moved from the radially outer side of the socket 18 to the radially inner side by a crimping device, and the socket 18 is crimped to a predetermined outer diameter, as shown in Figures 1(B), 2(B), and (C). With the socket 18 crimped, the diameter of the socket 18 is reduced, the uneven portion 1606 of the hose insertion portion 1604 bites into the inner peripheral portion of the hose 12, and the convex portion 1806 of the socket 18 bites into the outer peripheral surface 1808 of the hose 12, and the hose coupling fitting 10 and the hose 12 are joined.

[0013] In this embodiment, the inner peripheral surface 1402 of the crimping claw 14 is provided with the elongation suppressing portion 22A, which increases the gripping force of the crimping claw 14 on the outer peripheral surface 1808 of the socket 18 during crimping, and suppresses elongation of the outer peripheral portion of the socket 18 toward the opening 2002 in the axial direction during crimping. The inventors have determined that the outer peripheral portion and inner peripheral portion of the socket 18 elongate substantially integrally, and therefore, if it is possible to suppress elongation of the outer peripheral portion of the socket 18 toward the opening 2002 in the axial direction during crimping, it is possible to suppress elongation of the entire socket 18 in the axial direction, including the outer peripheral portion and inner peripheral portion, which suppresses variation in the degree of crimping of the hose 12 and is advantageous for joining the hose 12 and the hose coupling fitting 10 with the designed joining force.

[0014] Second Embodiment Next, a second embodiment will be described with reference to FIG. 4 . In the following embodiment, the same reference numerals are used to designate the same components as those in the first embodiment, and their description will be omitted. The differences will be focused on. In the second embodiment, the configuration of the elongation suppressing portion 22B differs from that of the elongation suppressing portion 22A of the first embodiment. In the second embodiment, the inner peripheral surface 1402 of the crimping claw 14 abuts against the outer peripheral surface 1808 of the socket 18 near the opening 2002. The inner peripheral surface 1402 of the crimping claw 14 is filled with a plurality of grooves 24 that suppress elongation of the outer peripheral portion of the socket 18 toward the opening 2002. The filled grooves 24 suppress elongation of the outer peripheral portion of the socket 18 toward the opening 2002. The elongation suppressing portion 22B is composed of these grooves 24. More specifically, the crimping claw 14 has a pair of side surfaces 1404 that rise from both circumferential sides of the inner peripheral surface 1402. A plurality of grooves 24 extending circumferentially around the inner peripheral surface 1402 and opening onto a pair of side surfaces 1404 are provided at equal intervals in the axial direction of the socket 18 on the inner peripheral surface 1402 of the crimping claw 14 facing the outer peripheral surface 1808 of the socket 18 near the opening 2002 of the socket 18. That is, the grooves 24 penetrate between the pair of side surfaces 1404, and both ends of the groove 24 in the extension direction are open at the pair of side surfaces 1404. In this embodiment, three grooves 24 are provided. The bottom of the groove 24 is V-shaped or U-shaped. A corner 1406 is formed at the point where a pair of opposing groove side surfaces 2402 of the groove 24 intersects with the inner peripheral surface 1402 of the crimping claw 14.

[0015] Groove 24 has a width of 0.3 mm to 1.0 mm in a direction perpendicular to the circumferential direction of inner circumferential surface 1402 and a depth of 0.3 mm to 1.0 mm from inner circumferential surface 1402, and elongation suppressing portion 22B is composed of a plurality of grooves 24. If the width of groove 24 is less than 0.3 mm, the amount of outer circumferential portion of socket 18 filled into groove 24 is too small, resulting in insufficient engagement with outer circumferential surface 1808 of socket 18. If the width of groove 24 exceeds 1.0 mm, a noticeable protrusion-like shape is formed on outer circumferential surface 1808 of socket 18. If the depth of groove 24 is less than 0.3 mm, the amount of outer circumferential portion of socket 18 filled into groove 24 is insufficient. If the depth of groove 24 exceeds 1.0 mm, the amount of outer circumferential portion of socket 18 filled into groove 24 is too large, resulting in insufficient effective crimping. In addition, if one groove 24 is provided on the inner surface 1402 of the crimping claw 14 near the opening 2002, the socket 18 will stretch in the axial direction when crimped, so two or more grooves 24 are required.

[0016] In this embodiment, as shown in Figures 1 and 2, similarly to the first embodiment, with the hose 12 inserted into the annular space 20, the eight crimping claws 14 arranged radially outside the socket 18 are moved from the radially outside to the radially inside of the socket 18 by the crimping device, and with the socket 18 crimped, the socket 18 is reduced in diameter, the uneven portion 1606 of the hose insertion portion 1604 bites into the inner periphery of the hose 12, and the convex portion 1806 of the socket 18 bites into the outer periphery 1808 of the hose 12, thereby connecting the hose coupling fitting 10 and the hose 12.

[0017] Furthermore, multiple grooves 24 extending circumferentially around the inner surface 1402 are provided at intervals in the axial direction of the socket 18 at the portion of the inner surface 1402 of the crimping claw 14 facing the outer peripheral surface 1808 of the socket 18 near the opening 2002.When crimping, the portions of the outer periphery of the socket 18 that extend toward the opening 2002 in the axial direction of the socket 18 enter and fill the grooves 24, which provide resistance when the outer periphery of the socket 18 tries to extend toward the opening 2002 of the annular space 20 in the axial direction of the socket 18, thereby being advantageous in suppressing extension of the outer periphery of the socket 18 toward the opening 2002 when crimping. Furthermore, corners 1406 are formed at the points where a pair of opposing groove side surfaces 2402 of groove 24 intersect with the inner peripheral surface 1402 of crimping claw 14, so that stress is concentrated at the points on outer peripheral surface 1808 of socket 18 where the pair of corners 1406 of groove 24 come into contact when crimping, thereby increasing the gripping force of crimping claw 14 on the points on outer peripheral surface 1808 of socket 18 closer to opening 2002, which is advantageous in suppressing extension of the outer peripheral portion of socket 18 in the axial direction toward opening 2002 when crimping.

[0018] Therefore, it is possible to suppress the overall axial elongation of the socket 18, including its outer and inner circumferential portions, which is advantageous in suppressing variation in the degree of crimping of the hose 12 and coupling the hose 12 and the hose coupling fitting 10 with the designed coupling force. Note that the groove 24 does not have to pass through between the pair of side surfaces 1404, but if it passes through between the pair of side surfaces 1404 as in the embodiment, the amount of the outer circumferential portion of the socket 18 that is filled into the groove 24 is ensured, which is advantageous in suppressing the elongation of the outer circumferential portion of the socket 18 toward the opening 2002 and is also advantageous in making the groove 24 easier to process. Furthermore, for example, if grooves 24 were provided over the entire inner surface 1402 of the crimping claw 14 at equal intervals in the longitudinal direction of the inner surface 1402, it is conceivable that too much of the outer periphery of the socket 18 would be filled into the grooves 24, resulting in insufficient effective crimping. Therefore, from the standpoint of suppressing extension of the outer periphery of the socket 18 toward the opening 2002, it is preferable to limit the provision of multiple grooves 24 to the portions of the inner surface 1402 of the crimping claw 14 that abut against the portions of the outer periphery 1808 of the socket 18 closer to the opening 2002.

[0019] Third Embodiment Next, a third embodiment will be described with reference to FIG. 5 . The third embodiment is a modified example of the expansion suppressing portion 22B of the second embodiment. In the expansion suppressing portion 22C of the third embodiment, a plurality of grooves 24 are provided in the inner peripheral surface 1402 of the crimping claws 14 at a location facing the outer peripheral surface 1808 of the socket 18 near the opening 2002. The shape, width, depth, and number of the bottoms of the grooves 24 are the same as those in the second embodiment, but three grooves 24 are provided at irregular intervals in the axial direction of the inner peripheral surface 1402 at a location facing the outer peripheral surface 1808 of the socket 18 near the opening 2002 of the socket 18. As with the second embodiment, the third embodiment also makes it possible to suppress the overall axial elongation of the socket 18, including the outer surface 1808 and the inner periphery, thereby suppressing variation in the degree of crimping of the hose 12 and being advantageous in joining the hose 12 and the hose coupling fitting 10 with the designed joining force.

[0020] Fourth Embodiment Next, a fourth embodiment will be described with reference to FIG. 6 . The fourth embodiment is a modified example of the elongation suppressing portion 22B of the second embodiment, and the configuration of an elongation suppressing portion 22D of the fourth embodiment differs from that of the elongation suppressing portion 22B of the second embodiment. A plurality of X-shaped grooves 26 in plan view, each consisting of two linear grooves 24 that intersect with each other and open to a pair of side surfaces 1404, are provided at intervals in the axial direction of the socket 18 on the inner peripheral surface 1402 of the crimping claw 14, which abuts against a portion of the outer peripheral surface 1808 of the socket 18 near the opening 2002. A pair of opposing groove side surfaces 2402 of each linear groove 24 intersects with the inner peripheral surface 1402 of the crimping claw 14 to form a corner 1406. In this embodiment, two X-shaped grooves 26 are provided, and the elongation suppressing portion 22D of the fourth embodiment is composed of two X-shaped grooves 26. The bottoms of the linear grooves 24 are V-shaped or U-shaped. As in the second embodiment, the linear grooves 24 are formed with a width of 0.3 mm to 1.0 mm and a depth from the inner circumferential surface 1402 of 0.3 mm to 1.0 mm, and the elongation suppressing portion 22D is formed with two X-shaped grooves 26, and is formed with four linear grooves 24 that intersect with each other.

[0021] According to the fourth embodiment, portions of outer peripheral surface 1808 of socket 18 enter inside linear grooves 24 that constitute X-shaped groove 26 during crimping, and provide resistance to the socket 18's tendency to extend axially toward opening 2002 of annular space 20, which is advantageous in suppressing extension of the outer peripheral portion of socket 18 toward opening 2002 during crimping. Furthermore, corners 1406 are formed at the locations where the pair of groove side surfaces 2402 and the inner peripheral surfaces 1402 of crimping claws 14 intersect, so stress concentration occurs at the locations of outer peripheral surface 1808 of socket 18 with which the pair of corners 1406 of linear grooves 24 come into contact during crimping, thereby increasing the gripping force of crimping claws 14 on the portions of outer peripheral surface 1808 of socket 18 that are closer to opening 2002, which is advantageous in suppressing extension of the outer peripheral portion of socket 18 toward opening 2002 during crimping. Therefore, the overall axial elongation of the socket 18, including its outer and inner circumferential portions, can be suppressed, which is advantageous in suppressing variation in the degree of tightening of the hose 12 and joining the hose 12 and hose coupling fitting 10 with the designed joining force.

[0022] In the first embodiment, the expansion suppressing portion 22A is provided over the entire inner circumferential surface 1402 of the crimping claw 14 to increase the gripping force on the outer circumferential surface 1808 of the socket 18 and suppress expansion toward the opening 2002 of the annular space 20 in the axial direction of the socket 18 during crimping, and in the second to fourth embodiments, the expansion suppressing portions 22B, 22C, and 22D made up of a plurality of grooves 24 are provided in a portion of the inner circumferential surface 1402 of the crimping claw 14 that faces the outer circumferential surface 1808 of the socket 18 closer to the opening 2002. However, in the present invention, both the expansion suppressing portion 22A of the first embodiment and the expansion suppressing portions 22B, 22C, and 22D of the second, third, and fourth embodiments may be provided on the inner circumferential surface 1402 of the crimping claw 14. In this case, a first elongation suppressing portion consisting of one of the elongation suppressing portions 22B, 22C, and 22D of the second, third, and fourth embodiments is provided at a portion of the inner circumferential surface 1402 of the crimping claw 14 that abuts against a portion of the outer circumferential surface 1808 of the socket 18 near the opening 2002. Furthermore, a second elongation suppressing portion consisting of the elongation suppressing portion 22A of the first embodiment is provided at the remaining portion of the inner circumferential surface 1402 of the crimping claw 14. This configuration also makes it possible to suppress the overall axial elongation of the socket 18, including its outer and inner circumferential portions, thereby suppressing variation in the degree of crimping of the hose 12 and being advantageous in coupling the hose 12 to the hose coupling fitting 10 with the designed coupling force.

[0023] REFERENCE SIGNS LIST 10 hose coupling fitting 12 hose 14 crimping claw 1402 inner peripheral surface of crimping claw 1404 side surface 1406 corner portion 16 nipple 1602 device side connection portion 1604 hose insertion portion 1606 uneven portion 1608 mounting recess 18 socket 1802 one end of socket 1804 other end of socket 1806 convex portion 1808 outer peripheral surface of socket 20 annular space 2002 opening 22A, 22B, 22C, 22D stretch suppressing portion 24 groove 2402 groove side surface 26 X-shaped groove

Claims

1. A crimping claw of a hose coupling fitting which is arranged at intervals circumferentially on the radial outside of an outer circumferential surface of a socket when a hose is inserted into the annular space between a nipple and a socket and which crimps the socket by moving radially inward of the socket, wherein the point where the crimping claw abuts the outer circumferential surface of the socket is formed by an inner circumferential surface consisting of a cylindrical surface that matches the outer circumferential surface of the socket after crimping, and the inner circumferential surface of the crimping claw is provided with an extension suppressing portion that increases the gripping force against the outer circumferential surface of the socket and suppresses extension of the outer circumferential part of the socket in the axial direction of the socket when the socket is crimped.

2. A crimping claw as described in claim 1, characterized in that the inner peripheral surface of the crimping claw is formed with a surface roughness of Ra 12.5 or more and Ra 25 or less, and the elongation suppressing portion is formed by the inner peripheral surface of the crimping claw having said surface roughness.

3. A crimping claw of a hose coupling fitting, which is arranged at intervals in the circumferential direction of the outer circumferential surface of a socket on the radially outer side of the outer circumferential surface of the socket when a hose is inserted into the annular space between a nipple and a socket, and which moves in the radially inward direction of the socket to crimp the socket, wherein one axial end of the socket is connected to the nipple so as to be immovable in the axial direction, and the other axial end of the socket forms an opening of the annular space, the portion where the crimping claw abuts on the outer circumferential surface of the socket is formed by an inner circumferential surface consisting of a cylindrical surface that matches the outer circumferential surface of the socket after crimping, and an elongation suppressing portion is provided on the inner circumferential surface of the crimping claw for suppressing elongation of the outer circumferential portion of the socket in the axial direction when the socket is crimped, and the elongation suppressing portion is formed on the portion of the inner circumferential surface of the crimping claw that abuts on a portion of the outer circumferential surface of the socket near the opening, and the portion of the outer circumferential portion of the socket that extends in the axial direction when crimped is filled, and the filled portion is composed of a plurality of grooves that suppress elongation of the outer circumferential portion of the socket. A crimping claw characterized by:

4. The crimping claw according to claim 3, characterized in that the groove extends in a direction intersecting the axial direction when viewed from a direction perpendicular to the axial direction of the inner peripheral surface, the width of the groove in the direction perpendicular to the extension direction of the groove is 0.3 mm or more and 1.0 mm or less, and the depth of the groove from the inner peripheral surface is 0.3 mm or more and 1.0 mm or less.

5. A crimping claw as claimed in claim 3, characterized in that the crimping claw has a pair of side surfaces rising from both circumferential sides of the inner peripheral surface, the groove penetrates between the pair of side surfaces, and both ends in the extension direction of the groove are open on the pair of side surfaces.

6. The crimping claw according to claim 3, characterized in that the groove is configured to include a pair of groove surfaces opposing each other, and a location where the pair of groove surfaces intersects with the inner circumferential surface is formed as a corner.

7. The crimping claw according to claim 3, characterized in that a plurality of said grooves are provided at intervals in the axial direction of said inner circumferential surface.

8. The crimping claw according to claim 3, characterized in that the grooves are formed as X-shaped grooves in which two of the grooves intersect.

9. A crimping claw of a hose coupling fitting, which is arranged at intervals in the circumferential direction of an outer circumferential surface of a socket on the radially outer side of the outer circumferential surface of the socket when a hose is inserted into the annular space between a nipple and a socket, and which moves in the radially inward direction of the socket to crimp the socket, wherein one axial end of the socket is connected to the nipple so as to be immovable in the axial direction, and the other axial end of the socket forms an opening of the annular space, the location where the crimping claw comes into contact with the outer circumferential surface of the socket is formed by an inner circumferential surface consisting of a cylindrical surface that matches the outer circumferential surface of the socket after crimping, and a first elongation suppressing portion is provided to suppress elongation of the outer circumferential portion of the socket in the axial direction when the socket is crimped, and the first elongation suppressing portion is formed at a location on the inner circumferential surface of the crimping claw that comes into contact with a location on the outer circumferential surface of the socket near the opening, and a location of the outer circumferential portion of the socket that extends in the axial direction when the socket is crimped is filled, and the filled location is composed of a plurality of grooves that suppress elongation of the outer circumferential portion of the socket, a second elongation suppressing portion is provided on the remaining inner peripheral surface of the fastening claw, the second elongation suppressing portion increasing the gripping force on the outer peripheral surface of the socket and suppressing elongation of the outer peripheral portion of the socket in the axial direction when the socket is fastened.

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