JP7015954B1 - Press caulking die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To airtightly or liquidally connect a pipe joint and a pipe element while reducing the formation of a surplus regardless of the material constituting the press type pipe joint and the pipe element. SOLUTION: The annular groove corresponding to the annular bulge of the press type pipe joint and the contracted diameter portion which is a portion located on both sides or one side of the annular bulge in the axial direction of the press type pipe joint are arranged so as to surround the annular groove portion. A press caulking die that has a molded surface on which six flat pressing surfaces facing the contracted diameter portion are formed and presses the contracted diameter portion with the pressed surface to reduce the diameter of the contracted diameter portion. In the mold, the press caulking die is divided into two or three partial dies around the axis of the press type pipe joint, and the extension surface of the adjacent pressing surface is between the adjacent pressing surfaces in each partial die. A recess is provided to define a space extending outward in the radial direction of the press type pipe joint rather than both or one of them. [Selection diagram] Fig. 2

Description

The present invention relates to a press caulking die. More specifically, the present invention relates to a press caulking die capable of reliably and airtightly connecting a press type pipe joint and a piping element.

For example, in the construction of a piping system composed of connecting thin-walled piping elements made of metal such as iron such as stainless steel, for example, from the viewpoint of ensuring workability and safety, firearms and the like are used. It is common to use mechanical pipe fittings that do not require use. Mechanical type pipe fittings are classified into various types such as press type, pipe expansion type, nut type, rolled screw type, insertion type and coupling type according to the standard (SAS322) defined by the Stainless Steel Association.

According to the mechanical type pipe joint, the pipe elements are connected to each other by inserting the end of the straight pipe as a pipe element into the pipe joint (socket part) and deforming (caulking) the annular bulging part. And the piping system can be organized. As a specific example of such a mechanical type pipe joint, for example, "press type pipe joint" disclosed in Patent Document 1 (Patent No. 3436822) can be mentioned. In this press-type pipe joint, an annular seal member (O-ring) made of an elastic material is attached to the inside (annular groove) of the annular bulge formed in the socket portion, and the end portion of the piping element (connecting pipe) is attached. (Pipe end) is inserted inside the socket portion and the sealing member. Then, while this state is maintained, both side portions sandwiching the annular bulging portion and the annular bulging portion in the axial direction of the socket portion are diameter-reduced (caulked) by a press caulking die, and are inwardly oriented in the radial direction (caulking). The sealing member is compressed in the centripetal direction), and the pipe joint and the piping element are airtightly or liquidtightly connected.

FIG. 13 is a schematic view showing how another pipe element is connected to a press-type pipe joint integrally formed at the pipe end of the pipe element. In the example shown in FIG. 13, the socket portion 221 is integrally formed over a certain range at the pipe end of the pipe element 211. An annular bulging portion 222 is integrally formed in the socket portion 221, and an annular sealing member (not shown) is incorporated inside the annular bulging portion 222. The press type pipe joint 220 is composed of the socket portion 221, the annular bulging portion 222, and the sealing member.

When connecting the other piping element 212 to the press type pipe joint 220, as shown in the figure by the black arrow, the piping element is inside the socket portion 221 of the press type pipe joint 220 and the seal member (not shown). The pipe end of 212 is inserted. Next, while this state is maintained, the portions on both sides of the annular bulging portion 222 and the socket portion 221 sandwiching the annular bulging portion 222 (see the shaded portion 223 shown in the figure) are press caulked (not shown). The diameter is reduced (caulked) by a mold, and the piping element 212 and the press type pipe joint 220 are airtightly or liquidtightly connected. Further, since a reduced diameter portion having a substantially hexagonal cross section (hereinafter, may be referred to as a “hexagonal cross section reduced diameter portion”) is formed on both sides of the annular bulging portion 222, the piping element 212 and the piping element 212 are formed. The occurrence of relative movement (eg, indexing and / or disconnection, etc.) with the press type pipe joint 220 is also reduced.

The hexagonal reduced diameter portion has a cavity portion having a substantially hexagonal cross section corresponding to the hexagonal cross-sectional reduced diameter portion, and a plurality (typically two or three) partial gold portions in the circumferential direction. By moving the press caulking die divided into molds (partial dies) inward in the radial direction to reduce the diameter of the socket portion (both or one of the portions on both sides sandwiching the annular bulging portion in the axial direction). It is formed. It is impossible to uniformly and annularly reduce the diameter of the annular bulge due to inward (centripetal) movement in the radial direction from such a finite number of directions (for example, two or three directions). However, the cross section of both sides (in some cases, one side) (hereinafter, sometimes referred to as "reduced diameter portion") sandwiching the annular bulging portion in the axial direction of the socket portion is approximately hexagonal. In the process of reducing the diameter so as to be, the material constituting the annular bulging portion is pulled by the reduced diameter portion. As a result, the annular bulge can be uniformly and annularly reduced in diameter.

Therefore, in order to reduce the diameter of the annular bulge uniformly and annularly, it is important to reduce the diameter of the reduced diameter portion so that the shape of the cross section of the hexagonal reduced diameter portion becomes a regular hexagon as accurately as possible. Is. Then, by reducing the diameter of the annular bulging portion uniformly and annularly, the sealing member made of the annular elastic body contained in the annular bulging portion is also uniformly compressed, and the straight pipe portion of the piping element and the press type are used. It can be airtightly or liquidtightly connected to the pipe joint. However, in reality, it is not easy to reduce the diameter of the reduced diameter portion so that the shape of the cross section of the hexagonal reduced diameter portion becomes an accurate regular hexagon so that the annular bulging portion is uniformly and annularly reduced in diameter. do not have. Hereinafter, a case where a hexagonal cross-sectional reduced diameter portion is formed by using a press caulking die divided into two partial dies will be described.

14 (a), 15 and 16 (a) are press-type pipes using a press caulking die according to the prior art (hereinafter, may be simply referred to as “conventional caulking die”). It is a schematic diagram which shows the contracted diameter part at the start time of the process of connecting a joint and a piping element, the intermediate stage of diameter reduction, and the time when diameter reduction is almost completed. Further, FIG. 16B is an enlarged view of a portion surrounded by a thick broken line in FIG. 16A.

The pair of partial dies 310 and 320 constituting the conventional caulking die 300 are formed with three pressing surfaces 313a to 313c and three pressing surfaces 323a to 323c, respectively. As illustrated in FIG. 14, the socket portion 221 of the press-type pipe joint 220 in which the pipe end of the pipe element 212 is inserted is installed in the space surrounded by these six pressing surfaces. At this time, the annular bulging portion (not shown) formed in the socket portion 221 is fitted into the annular groove (not shown) formed on the molding surfaces of the pair of partial molds 310 and 320. The partial dies 310 and 320 and the press type pipe joint 220 are arranged.

Then, as illustrated in FIGS. 15 and 16, by bringing the pair of partial molds 310 and 320 close to each other, the three pressing surfaces 313a to 313c and the three pressing surfaces 323a to 323c each have an inner diameter. The outer peripheral surface of the socket portion 221 is pressed in the direction (centripetal direction). As a result, as illustrated in FIG. 16A, a reduced diameter portion (hexagonal cross-sectional reduced diameter portion) having a substantially regular hexagonal cross section is obtained. At this time, the material may not fit into the shape of the corner portion between the two adjacent pressing surfaces, and the material may not fit in the cavity of the conventional caulking die. As a result, as illustrated in FIG. 16B, a surplus portion (knob portion) may be formed at the mating surface (divided surface of the caulking mold) of the pair of partial molds 310 and 320 (thick broken line). See the part enclosed by).

The extra portion (knob portion) as described above may be continuously formed not only from the hexagonal cross-section reduced diameter portion but also from the hexagonal cross-section reduced diameter portion to the annular bulging portion. 17 and 18, respectively, show an annular bulge in the middle of the diameter reduction in the process of connecting the press type pipe joint 220 and the pipe element 212 using the conventional caulking die 300 and when the diameter reduction is almost completed. It is a schematic diagram which shows the part. As illustrated in FIGS. 17 and 18, a surplus portion (knob portion) may be formed not only in the contracted diameter portion of the press type pipe joint 220 but also in the annular bulging portion.

In the above case, depending on the shape and / or size of the cross section (cross section by the plane perpendicular to the longitudinal direction) of the surplus portion (knob portion), the pipe inserted inside the socket portion 221 of the press type pipe joint 220. A gap not only between the element 212 and the surplus portion (knob portion), but also between the annular seal member (O-ring) 230 mounted on the inside (annular groove) of the annular bulge portion and the surplus portion (knob portion). May occur (see the area surrounded by the thick dashed line). In this case, the gap may be a flow path (axial bypass flow path) passing through the hexagonal cross-section reduced diameter portion-annular bulging portion-hexagonal cross-section reduced diameter portion, and the press type pipe joint 220 and the piping element. It may be difficult to achieve an airtight or liquidtight connection with the 212. Therefore, in order to connect the press-type pipe joint and the piping element in an airtight or liquid-tight manner by diameter reduction processing (caulking), the surplus portion (knob portion) regardless of the material constituting the press-type pipe joint and the piping element. ) Is desired to be reduced.

As for the above-mentioned problems, for example, when the friction coefficient between the socket portion of the press type pipe joint and the molding surface of the die is large, the socket portion slides smoothly along the molding surface of the press caulking die. It is considered that this is due to the fact that the material constituting the socket portion is intensively plastically flowed toward the split surface of the press caulking die. That is, it is considered that a surplus portion (knob portion) is formed by a phenomenon in which the strain due to the molding of the hexagonal cross-section reduced diameter portion is finally concentrated in the vicinity of the split surface of the press caulking die.

As a means for absorbing the strain due to deformation during caulking as described above, for example, in Patent Document 2 (Utility Model Registration No. 3052402), a metal pipe outerly fitted to the joint is provided on the outer peripheral surface of the joint. It has been proposed to provide a plurality of relief portions (recesses) in the caulking blade portion for pushing into the annular groove portion by caulking. According to this, since the strain due to the deformation can escape to the relief portion, the diameter reduction state in the portion other than the relief portion becomes appropriate, and it is said that an appropriate caulking state can be obtained as a whole. However, in this method, a part of the metal pipe is intentionally projected at the relief part in order to alleviate the distortion due to deformation, and even if caulking can be realized as a whole, the metal pipe and the joint are airtight or liquid. It is not possible to reliably achieve a tight connection.

Further, in Patent Document 3 (US Patent Application Publication No. 2021 / 0008611), the molding surface of one partial mold is composed of three planes, and the molding surface of the other partial mold is a curved surface and a concave portion. A press caulking die composed of is proposed. The recess of the other partial mold is thought to play a stopper function for "preventing rotation (preventing indexing)", and the diameter-reduced part is made so that the cross-sectional shape of the diameter-reduced part becomes an accurate regular hexagon. It is not intended to form. Further, the molding surface of one of the partial molds is composed of planes corresponding to three adjacent sides of the regular hexagon, similar to the partial mold constituting the conventional caulking mold described above, and is formed by the conventional caulking mold. The above-mentioned problem cannot be solved.

Japanese Patent No. 3436822 Utility Model Registration No. 3052402 U.S. Patent Application Publication No. 2021/0008611

As described above, in the art, the hexagonal cross-sectional reduced diameter portion is accurately formed while reducing the formation of the surplus portion (knob portion) regardless of the material constituting the press type pipe joint and the piping element. There is a demand for a press caulking die capable of airtightly or liquid-tightly connecting a pipe joint and the pipe element.

Therefore, as a result of diligent research, the present inventor has provided a recess having a space extending outward in the radial direction from the pressing surface between adjacent pressing surfaces of the partial dies constituting the press caulking die. We have found that the above problems can be solved.

Specifically, the press caulking die according to the present invention (hereinafter, may be referred to as "the caulking die of the present invention") is provided with a molded surface in which an annular groove portion and a pressing surface are formed, and is pressed. It is a press caulking die configured to reduce the diameter of the contracted diameter portion by pressing the contracted diameter portion of the type pipe joint with a pressing surface. The annular groove portion is an annular recess having a shape corresponding to the annular bulging portion of the press type pipe joint. The contracted diameter portion is a portion of the press type pipe joint located on both sides or one side of the annular bulge portion in the axial direction of the press type pipe joint. The pressing surface is six planes arranged around the axis of the press type pipe joint so as to surround the reduced diameter portion and facing the reduced diameter portion.

The caulking die of the present invention is divided into two or three partial dies around the axis of the press type pipe joint. When the caulking die of the present invention is divided into two partial dies, each partial die has three pressing surfaces. When the caulking die of the present invention is divided into three partial molds, each partial mold has two pressing surfaces.

Further, in each partial mold, the corner portion, which is a portion between the adjacent pressing surfaces, is formed from both or one of the two planes obtained by extending the adjacent pressing surfaces. There is also a recess that defines a space that extends outward in the radial direction of the press-type pipe joint.

As described above, in each partial die constituting the caulking die of the present invention, recesses defining a space extending outward in the radial direction of the press type pipe joint from both or one of the virtual pressing surfaces are adjacent to each other. It is provided at a corner portion which is a portion between the pressing surfaces. Therefore, the contact area between the pressing surface and the contracted diameter portion is smaller than that of the conventional caulking die. As a result, even when the friction coefficient between the socket portion of the press type pipe joint and the molding surface of the die is large, the contracted diameter portion is smoothly slid along the pressing surface to form the split surface of the die. It is possible to reduce the amount of material that plastically flows intensively toward it. That is, it is possible to reduce the occurrence of a phenomenon in which the strain due to the reduced diameter of the diameter-reduced portion is concentrated in the vicinity of the divided surface of the mold. Further, since the space defined by the concave portion exists in the corner portion, the strain due to the reduced diameter of the contracted diameter portion can be alleviated even in the concave portion. Therefore, according to the caulking die of the present invention, it is possible to suppress the formation of a surplus portion (knob portion) and reliably connect the press type pipe joint and the piping element in an airtight or liquidtight manner.

Other objects, other features and accompanying advantages of the invention will be readily understood from the description of each embodiment of the invention described with reference to the following drawings.

It is a schematic front view which illustrates the structure of the press caulking die (first caulking die) which concerns on 1st Embodiment of this invention. It is a schematic perspective view which shows an example of the structure of the two partial molds constituting the 1st caulking mold illustrated in FIG. 1 (a). It is a schematic plan view when the two partial molds illustrated in FIG. 2 are observed from the split surface side. Schematic side view of the first caulking die illustrated in (a) of FIG. 1 Schematic cross-sectional view of the first caulking die by a plane represented by lines BB in (a) and (a). b). It is a schematic diagram which shows the outline of the cross section by the plane including the axis of the press type pipe joint represented by the line AA of the partial die 120 exemplified in FIG. 3 (b).

It is a schematic diagram which shows the contracted diameter part at the start time of the process of connecting a press type pipe joint and a pipe element using a 1st caulking die. It is a schematic diagram which shows the reduced diameter part in the middle stage of the diameter reduction in the process of connecting a press type pipe joint and a piping element by using a 1st caulking die. It is a schematic diagram which shows the reduced diameter part at the time when the reduced diameter is almost completed in the process of connecting a press type pipe joint and a piping element by using a 1st caulking die. It is a schematic diagram which shows the annular bulging part at the time when the diameter reduction is almost completed in the process of connecting a press type pipe joint and a pipe element using a 1st caulking die.

Schematic perspective view (a) illustrating the configuration of one of the pair of partial dies constituting the press caulking die (second caulking die) according to the second embodiment of the present invention. It is a schematic plan view (b) when the partial mold illustrated in (a) is observed from the division surface side. A schematic front view (a) of a partial die constituting the press caulking die (third caulking die) according to the third embodiment of the present invention, and a schematic cross-sectional view of a portion where a pressing surface is formed (a). b) and is a schematic cross-sectional view (c) of the portion provided with the recess. In the schematic front views (a) and (a) of one of the pair of partial dies constituting the press caulking die (fifth caulking die) according to the fifth embodiment of the present invention. Schematic cross-sectional view of the portion where the pressing surface of the illustrated partial mold is formed, and a schematic plan view when the partial mold illustrated in (a) and (b) is observed from the split surface side. (C). It is a schematic diagram which shows the mode that another piping element is connected to the press type pipe joint formed integrally with the pipe end of a piping element.

It is a schematic diagram which shows the contracted diameter part at the start of the process of connecting a press type pipe joint and a piping element using a press caulking die (conventional caulking die) which concerns on the prior art. It is a schematic diagram which shows the reduced diameter part in the middle stage of the diameter reduction in the process of connecting a press type pipe joint and a piping element by using a conventional caulking die. It is a schematic diagram which shows the reduced diameter part at the time when the reduced diameter is almost completed in the process of connecting a press type pipe joint and a piping element using a conventional caulking die. It is a schematic diagram which shows the annular bulging part in the middle stage of diameter reduction in the process of connecting a press type pipe joint and a pipe element by using the conventional caulking die. It is a schematic diagram which shows the annular bulging part at the time when the diameter reduction is almost completed in the process of connecting a press type pipe joint and a pipe element using a conventional caulking die.

<< First Embodiment >>
Hereinafter, the press caulking die according to the first embodiment of the present invention (hereinafter, may be referred to as “first caulking die”) will be described with reference to the drawings.

<Constitution>
The first caulking die is provided with a molded surface in which an annular groove portion and a pressing surface are formed, and is configured to reduce the diameter of the compressed diameter portion by pressing the contracted diameter portion of the press type pipe joint with the pressing surface. It is a pressed caulking die. The annular groove portion is an annular recess having a shape corresponding to the annular bulging portion of the press type pipe joint. The contracted diameter portion is a portion of the press type pipe joint located on both sides or one side of the annular bulge portion in the axial direction of the press type pipe joint. The pressing surface is six planes arranged around the axis of the press type pipe joint so as to surround the reduced diameter portion and facing the reduced diameter portion.

The first caulking die is divided into two or three partial dies around the axis of the press type pipe joint. When the first caulking die is divided into two partial molds, each partial mold has three pressing surfaces. When the first caulking die is divided into three partial molds, each partial mold has two pressing surfaces.

Further, in each partial mold, the corner portion, which is a portion between the adjacent pressing surfaces, is formed from both or one of the two planes obtained by extending the adjacent pressing surfaces. There is also a recess that defines a space that extends outward in the radial direction of the press-type pipe joint.

FIG. 1 is a schematic front view illustrating the configuration of the first caulking die. The first caulking die 101a exemplified in (a) is divided into two partial dies 110 and 120. The partial mold 110 has three pressing surfaces 113a, 113b and 113c, and the partial mold 120 has three pressing surfaces 123a, 123b and 123c. The first caulking die 101b exemplified in (b) is divided into three partial dies 110 to 130. The partial mold 110 has two pressing surfaces 113a and 113b, the partial mold 120 has two pressing surfaces 123a and 123b, and the partial mold 130 has two pressing surfaces 133a and 133b. In the following description, the first caulking die 101a divided into two partial dies 110 and 120 will be described. However, also for the first caulking die 101b divided into the three partial dies 110 to 130, the first caulking is performed except that the number of partial dies and the number of pressing surfaces of each partial die are different. It is the same as the mold 101a.

FIG. 2 is a schematic perspective view showing an example of the configuration of the two partial molds 110 and 120 constituting the first caulking mold 101a exemplified in FIG. 1 (a). However, in the partial mold 110 exemplified in FIG. 2 (a), the partial mold 110 is rotated by 180 ° clockwise so that the divided surface of the partial mold 110 illustrated in FIG. 1 (a) faces upward. It is in a state of being made to. FIG. 3 is a schematic plan view when the two partial molds 110 and 120 illustrated in FIG. 2 are observed from the split surface side. In both FIGS. 2 and 3, the partial mold 110 is drawn in (a) and the partial mold 120 is drawn in (b), respectively. Further, FIG. 4 shows a first caulking die with a plane represented by lines BB in the schematic side views (a) and (a) of the first caulking die 101a exemplified in FIG. 1 (a). It is a schematic cross-sectional view (b) of 101a.

An annular groove portion 112 and three pressing surfaces 113a, 113b and 113c are formed on the molding surface 111 included in the partial mold 110 exemplified in FIGS. 2 and 3A and FIG. 4B. .. The molding surface 111 is the surface of the partial mold 110 on the side (inside) facing the press type pipe joint (not shown) to be caulked by the first caulking die 101a. The annular groove portion 112 is an annular recess having a shape corresponding to the annular bulging portion of the press type pipe joint. The pressing surfaces 113a, 113b and 113c are arranged around the axis of the press type pipe joint while facing each of the contracted diameter portions which are the portions located on both sides of the annular bulge portion in the axial direction of the press type pipe joint. It is three planes provided in. That is, in the partial die 110 constituting the first caulking die 101a, a pair of pressing surfaces 113a, a pair of 113b, and a pair of 113c (so that they face each other with the annular groove portion 112 sandwiched in the axial direction of the press type pipe joint). That is, a total of 6 pressing surfaces) are provided.

Similar to the above, the molding surface 121 included in the partial mold 120 exemplified in FIGS. 2 and 3 (b) and FIG. 4 (b) includes an annular groove portion 122 and three pressing surfaces 123a, 123b and 123c. Is formed. The forming surface 121 is the surface of the partial die 120 on the side (inside) facing the press type pipe joint (not shown) to be caulked by the first caulking die 101a. The annular groove portion 122 is an annular recess having a shape corresponding to the annular bulging portion of the press type pipe joint. The pressing surfaces 123a, 123b and 123c are arranged around the axis of the press type pipe joint while facing each of the contracted diameter portions which are the portions located on both sides of the annular bulge portion in the axial direction of the press type pipe joint. It is three planes provided in. That is, also in the partial die 120 constituting the first caulking die 101a, a pair of pressing surfaces 123a, a pair of 123b, and a pair of 123c (so that they face each other with the annular groove portion 122 in the axial direction of the press type pipe joint). That is, a total of 6 pressing surfaces) are provided.

As a result, the first mold 101a composed of the two partial dies 110 and 120 as described above has an annular groove portion which is an annular recess having a shape corresponding to the annular bulge portion of the press type pipe joint. It is arranged around the axis of the press-type pipe joint so as to surround the contracted diameter portion, which is a part of the press-type pipe joint located on both sides of the annular bulge in the axial direction of the press-type pipe joint, and is arranged in the contracted diameter portion. It is provided with a pressing surface which is six opposite planes and a forming surface on which a pressing surface is formed. As long as the positional relationship between the press-type pipe joint and the pipe element (not shown) is sufficiently fixed and airtight or liquid-tight can be connected, the press-type pipe joint is not necessarily annular in the axial direction. It is not necessary to provide the reduced diameter portion on both sides of the bulging portion, and the reduced diameter portion may be provided only on one side of the annular bulging portion.

The first caulking die 101a is configured to reduce the diameter of the reduced diameter portion by pressing the reduced diameter portion with the six pressing surfaces 113a to 113c and 123a to 123c. Specifically, a socket portion of a press-type pipe joint in which the pipe end of the pipe element is inserted is installed in the space surrounded by these six pressing surfaces. At this time, the partial mold 110 and the partial mold 110 and the annular bulge portion formed in the socket portion are fitted to the annular groove portions 112 and 122 formed on the molding surfaces 111 and 121 of the pair of partial molds 110 and 120, respectively. The 120 and the press type pipe joint are arranged. Then, by bringing the pair of partial dies 110 and 120 close to each other by a driving device (for example, a press machine or the like) (not shown), the three pressing surfaces 113a to 113c and the three pressing surfaces 123a to 123c are directed inward in the radial direction (for example,). The contracted diameter portion is pressed in the centripetal direction). As a result, the diameter-reduced portion is reduced so that the shape of the cross section approaches a regular hexagon, and the hexagonal cross-section reduced diameter portion described above is formed.

At this time, as described above, in the press caulking die (conventional caulking die) according to the conventional technique, the material does not fit into the shape of the corner portion between the two adjacent pressing surfaces, and the cavity of the conventional caulking die. The material may not fit inside. As a result, a surplus portion (knob portion) may be formed on the divided surfaces of the pair of partial molds. Due to the formation of such a surplus portion (knob portion), an annular seal member mounted not only between the piping element and the surplus portion (knob portion) in the hexagonal cross-sectional reduced diameter portion but also inside the annular bulging portion (annular groove). There may be a gap between the (O-ring) and the extra portion (knob portion). In this case, the gap may be a flow path (axial bypass flow path) passing through the hexagonal cross-section reduced diameter portion, the annular bulge portion, and the hexagonal cross-section reduced diameter portion. It may be difficult to achieve an airtight or liquid-tight connection.

However, in the two partial dies 110 and 120 constituting the first caulking die 101a, a recess is provided at a corner portion which is a portion between adjacent pressing surfaces. Specifically, as illustrated in FIGS. 3 and 4B, in the partial mold 110, a recess 114a is provided between the adjacent pressing surfaces 113a and the pressing surfaces 113a, and the adjacent pressing surfaces 113b. A recess 114b is provided between the pressing surface 113c and the pressing surface 113c, respectively. On the other hand, in the partial mold 120, a recess 124a is provided between the adjacent pressing surface 123a and the pressing surface 123a, and a recess 124b is provided between the adjacent pressing surface 123b and the pressing surface 123c. ..

As described above, the recess is a space that extends outward in the radial direction of the press type pipe joint from both or one of the virtual pressing surfaces, which are two planes obtained by extending the adjacent pressing surfaces. It is a depression that defines. In other words, in a vertical projection onto a plane orthogonal to the axis of a press fitting, the space defined by the recesses (the recesses formed in the molded surface) is defined by six straight lines each passing through the six pressing surfaces. It extends to the outside of the hexagon to be formed.

FIG. 5 is a schematic view showing the outline of a cross section by a plane including the axis of the press type pipe joint represented by the line AA of the partial die 120 illustrated in FIG. 3 (b). In FIG. 5, the line Ca-Ca represents a virtual plane (virtual pressing surface Pa) obtained by extending the pressing surface 123a, and the line Cb-Cb represents a virtual plane obtained by extending the pressing surface 123b. The plane (virtual pressing surface Pb) is represented, and the line Cc-Cc represents a virtual plane (virtual pressing surface Pc) obtained by extending the pressing surface 123c. A recess 124a is provided at a corner portion between the pressing surface 123a and the pressing surface 123b, and the recess 124a is a press type pipe joint (shown) rather than at least one of the virtual pressing surface Pa and the virtual pressing surface Pb. It extends to the outside in the radial direction. Similarly, a recess 124b is provided at a corner portion between the pressing surface 123b and the pressing surface 123c, and the recess 124b is a press type pipe joint rather than at least one of the virtual pressing surface Pb and the virtual pressing surface Pc. It extends to the outside in the radial direction (not shown).

Although not shown, a cross section by a plane represented by a line A'-A' located on the opposite side of the line AA across the annular groove portion 122 of the partial mold 120 illustrated in FIG. 3 (b) is also shown. Same as above. Further, although not shown, the same applies to the other partial mold 110.

The structure of the recess (for example, shape and size, etc.) is, for example, the mechanical strength, hardness, friction coefficient and plasticity of the material constituting the press type pipe joint and the piping element with the molding surface of the first caulking die. Depending on various factors such as processing characteristics, it can be appropriately determined so that the desired effect of suppressing the remaining portion (knob portion) is achieved. Further, the space defined by the recess does not necessarily have to extend outward in the radial direction of the press type pipe joint from both or one of the virtual pressing surfaces of the adjacent pressing surfaces in the entire corner portion. That is, in the space defined by the recess, a portion that stays inside in the radial direction of the press type pipe joint may be included rather than any virtual pressing surface.

Here, a case where the diameter-reduced portion is reduced to form the hexagonal cross-sectional diameter-reduced portion by using the first caulking die 101a will be described.

6 and 7 (a) and 8 show the start time of the process of connecting the press type pipe joint and the piping element using the first caulking die 101a, the intermediate stage of diameter reduction, and the shrinkage, respectively. It is a schematic diagram which shows the contracted diameter part at the time when the diameter is almost completed. Further, FIG. 7B is an enlarged view of a portion surrounded by a thick broken line in FIG. 7A. Due to space limitations in the drawings, the reference numerals for the pressing surface and the concave portion are omitted in FIGS. 7 and 8.

As illustrated in FIG. 6, the pair of partial dies 110 and 120 constituting the first caulking die 101a are formed with three pressing surfaces 113a to 113c and three pressing surfaces 123a to 123c, respectively. In the space surrounded by these six pressing surfaces, the socket portion 221 of the press-type pipe joint 220 in which the pipe end of the pipe element 210 is inserted is installed. At this time, as described above, the annular bulging portion (not shown) formed in the socket portion 221 is fitted into the annular groove portion (not shown) formed on the molding surfaces of the pair of partial molds 110 and 120. As such, the partial dies 110 and 120 and the press type pipe joint 220 are arranged.

Then, the pair of partial molds 110 and 120 are brought close to each other as shown by the white arrows in FIG. 7A. As a result, the outer peripheral surface of the socket portion 221 is pressed inward (centric direction) in the radial direction by the three pressing surfaces 113a to 113c and the three pressing surfaces 123a to 123c.

At this time, in the press caulking die (conventional caulking die) according to the above-mentioned conventional technique, as described above, when the friction coefficient between the socket portion of the press type pipe joint and the molding surface of the die is large, etc. The socket portion cannot slide smoothly along the molding surface of the press caulking die. Therefore, the material constituting the socket portion is intensively plastically flowed toward the split surface of the press caulking die, and the strain due to the molding of the hexagonal cross-section reduced diameter portion is finally generated on the split surface of the press caulking die. It will be concentrated in the vicinity. As a result, a surplus portion (knob portion) tends to be formed on the mating surface (divided surface of the caulking mold) of the pair of partial molds.

However, in the first caulking die 101a, as illustrated in FIG. 6, recesses 114a, 114b, 124a and 114b are provided at the corners which are portions between the adjacent pressing surfaces in each partial die. There is. Therefore, in the first caulking die 101a, the total area of the pressing surface is smaller than that of the conventional caulking die. As a result, as shown by the black-painted double-headed arrow in FIG. 7B, even when the friction coefficient between the press-type pipe joint and the molded surface of the die is large, the shrinkage is applied along the pressing surface. The diameter portion can be smoothly slid to reduce the material that is intensively plastically flowed toward the split surface of the mold. That is, it is possible to reduce the occurrence of a phenomenon in which the strain due to the reduced diameter of the diameter-reduced portion is concentrated in the vicinity of the divided surface of the mold. Further, since the space defined by the concave portion (114a or the like) exists at the corner portion, the strain due to the reduced diameter of the contracted diameter portion can be alleviated also in the concave portion.

Due to the above effect, according to the first caulking die 101a, as illustrated in FIG. 8, the formation of a surplus portion (knob portion) is reduced regardless of the material constituting the press type pipe joint and the piping element. It is possible to form a reduced diameter portion (hexagonal cross-sectional reduced diameter portion) having a substantially hexagonal cross section having high symmetry, such as a hexagonal flower.

FIG. 9 is a schematic view showing an annular bulging portion in the middle stage of diameter reduction in the process of connecting the press type pipe joint and the piping element using the first caulking die 101a and at the time when the diameter reduction is almost completed. It is an enlarged view (b) of the part surrounded by a thick broken line in a) and (a). As described above, in the process of reducing the diameter of the reduced diameter portion (hexagonal cross-sectional reduced diameter portion) having a substantially hexagonal cross section, the material constituting the annular bulging portion is pulled by the reduced diameter portion. Be done. On the other hand, as described above, according to the first caulking metal fitting 101a, it is possible to form a hexagonal cross-sectional diameter-reduced portion having high symmetry while reducing the formation of a surplus portion (knob portion). As a result, as illustrated in FIG. 9, the annular bulging portion can be uniformly and annularly reduced in diameter. That is, according to the first caulking die 101a, the press-type pipe joint and the piping element can be reliably and airtightly connected.

<effect>
As described above, in each partial die constituting the first caulking die, a recess defining a space extending outward in the radial direction of the press type pipe joint rather than both or one of the virtual pressing surfaces is provided. It is provided at a corner portion which is a portion between adjacent pressing surfaces. Therefore, the contact area between the pressing surface and the contracted diameter portion is smaller than that of the conventional caulking die. As a result, even when the friction coefficient between the socket portion of the press type pipe joint and the molding surface of the die is large, the contracted diameter portion is smoothly slid along the pressing surface to form the split surface of the die. It is possible to reduce the amount of material that plastically flows intensively toward it. That is, it is possible to reduce the occurrence of a phenomenon in which the strain due to the reduced diameter of the diameter-reduced portion is concentrated in the vicinity of the divided surface of the mold. Further, since the space defined by the concave portion exists in the corner portion, the strain due to the reduced diameter of the contracted diameter portion can be alleviated even in the concave portion. Therefore, according to the first caulking die, the formation of the surplus portion (knob portion) can be suppressed, and the press-type pipe joint and the piping element can be reliably and airtightly connected.

<< Second Embodiment >>
Hereinafter, the press caulking die according to the second embodiment of the present invention (hereinafter, may be referred to as “second caulking die”) will be described with reference to the drawings.

As described above, in each partial die constituting the first caulking die, the contact area between the molded surface and the diameter-reduced portion is reduced by the recess provided between the adjacent pressing surfaces, and the shrinkage is reduced. By dispersing and / or alleviating the strain caused by the diameter reduction of the diameter portion, the formation of a surplus portion (knob portion) can be suppressed, and the press-type pipe joint and the piping element can be reliably and liquid-tightly connected. .. From the viewpoint of suppressing the formation of a surplus (knob portion) on the mating surface of the partial die (divided surface of the caulking die), the formed surface and the contracted diameter not only between the adjacent pressing surfaces but also in the vicinity of the divided surface. It is desirable to reduce the contact area with the portion and to disperse and / or alleviate the strain associated with the diameter reduction of the diameter-reduced portion.

<Constitution>
Therefore, the second caulking die is the first caulking die described above, and inclined portions are provided at both ends in the axial direction of the press-type pipe joint at both ends in the circumferential direction of the molding surface of the partial die. It is a press caulking die characterized by being present. The inclined portion is a portion inclined so as to move away from the axis of the press type pipe joint toward the end portion in the axial direction of the press type pipe joint.

FIG. 10 is a schematic perspective view illustrating the configuration of one of the partial molds 110 of the pair of partial molds constituting the second caulking mold 102 (a) and the partial molds exemplified in (a). It is a schematic plan view (b) when 110 is observed from the division surface side. (A) and (b) of FIG. 10 correspond to (a) of FIG. 2 and (a) of FIG. 3 referred to in the description of the partial mold 110 constituting the first caulking mold 101a, respectively.

As illustrated in FIG. 10A, both ends in the circumferential direction of the molding surface 111 of the partial die 110 constituting the second caulking die 102 (that is, molding) in the axial direction of the press type pipe joint. Inclined portions 115 are provided at the four corners of the surface 111 (see the portion surrounded by the thick dashed line). Further, as illustrated in FIG. 10B, the inclined portion 115 is a portion inclined so as to move away from the shaft AX of the press type pipe joint toward the end portion in the direction of the shaft AX of the press type pipe joint. .. As illustrated in FIG. 10B, in the vertical projection drawing of the second caulking die 102 onto the split surface, the inclined portion 115 is inclined at an angle θ with respect to the axis AX of the press type pipe joint. ..

The configuration of the inclined portion (for example, the shape, size, inclination angle with respect to the shaft of the press type pipe joint, etc.) is determined by, for example, the mechanical strength, hardness, and second caulking of the material constituting the press type pipe joint and the piping element. Depending on various factors such as the coefficient of friction with the molding surface of the mold and the plastic working characteristics, it can be appropriately determined so that the desired effect of suppressing the remaining portion (knob portion) is achieved. For example, the inclined portion may be formed of a flat surface or a curved surface as long as the above-mentioned requirements are satisfied. Further, the inclined portion may be composed of a combination of a flat surface and / or a curved surface. Further, although not shown, the same applies to the inclined portion provided on the molding surface 121 of the other partial mold 120.

<effect>
As described above, in each partial die constituting the second caulking die, inclined portions are provided at both ends in the axial direction of the press-type pipe joint at both ends in the circumferential direction of the molding surface. .. The inclined portion is inclined so as to move away from the axis of the press type pipe joint toward the end portion in the axial direction of the press type pipe joint. Therefore, in the second caulking die, the contact area between the molded surface and the reduced diameter portion is reduced not only between the adjacent pressing surfaces but also in the vicinity of the divided surface, and the strain due to the reduced diameter of the reduced diameter portion is reduced. Can be dispersed and / or relaxed. As a result, according to the second caulking die, the formation of a surplus (knob portion) on the mating surface (divided surface of the caulking die) of the partial die is more effectively suppressed, and the press type pipe joint and the piping element are formed. Can be more reliably connected airtightly or liquidtightly.

Although the inclined portion is also drawn in FIGS. 1 to 3 referred to in the above-mentioned description of the first caulking die 101a, the inclined portion is not an indispensable constituent requirement in the first caulking die.

<< Third Embodiment >>
Hereinafter, the press caulking die according to the third embodiment of the present invention (hereinafter, may be referred to as “third caulking die”) will be described with reference to the drawings.

As described above, in each of the partial dies constituting the first caulking die and the second caulking die, the contact area between the molded surface and the contracted diameter portion is provided by the recess provided between the adjacent pressing surfaces. By reducing and / or alleviating the strain associated with the diameter reduction of the diameter-reduced portion, the formation of a surplus portion (knob portion) is suppressed, and the press-type pipe joint and the piping element are reliably airtight or liquid-tight. Can be connected to.

On the other hand, as described above, it is impossible to uniformly and annularly reduce the diameter of the annular bulge by inward (centripetal) movement in the radial direction from a finite number of directions (for example, two or three directions). be. However, the reduced diameter portion located on both sides or one side of the annular bulge in the axial direction of the press type pipe joint is pressed by the six pressing surfaces so that the reduced diameter portion has a substantially hexagonal cross section. In the process of reducing the diameter, the material constituting the annular bulge is pulled by the reduced diameter portion. As a result, the annular bulge can be uniformly and annularly reduced in diameter.

However, if the proportion of the recesses on the molded surface is excessively large, the proportion of the portion pressed by the pressing surface on the molded surface becomes low, and the material constituting the annular bulging portion in the process of reducing the diameter of the diameter-reduced portion. May be difficult to be pulled by the contracted diameter portion. As a result, it may be difficult to reduce the diameter of the annular bulging portion uniformly and annularly. In particular, for example, when the recess is excessively long in the axial direction of the press type pipe joint and excessively deep in the vicinity of the annular groove portion, the above problem becomes more remarkable.

In the above case, in the molding surface between the concave portion and the annular groove portion in the axial direction of the press type pipe joint, the press type pipe joint is sufficiently in contact with the press type pipe joint in the process of reducing the diameter of the reduced diameter portion. There may be few or no parts that can be pressed against. Further, since the molded surface excluding the vicinity of the annular groove portion is divided in the circumferential direction (circumferential direction) by the concave portion, the stress of pulling the material constituting the annular bulging portion is mainly the axis in the process of reducing the diameter of the contracted diameter portion. It may only work in the direction. As a result, it is likely that it will be difficult to reduce the diameter of the annular bulge uniformly and annularly.

<Constitution>
Therefore, the third caulking die is the above-mentioned first caulking die or the second caulking die, and a gradual change portion is provided at the inner end portion in the axial direction of the press type pipe joint of the concave portion. It is a press caulking die characterized by. The gradual change portion is a portion in which the depth of the recess in the radial direction of the press-type pipe joint becomes shallower toward the inside in the axial direction of the press-type pipe joint.

FIG. 11 is provided with a schematic front view (a) of the partial mold 120 constituting the third caulking die 103, a schematic cross-sectional view (b) of the portion where the pressing surface 123c is formed, and a recess 124a. It is a schematic cross-sectional view (c) of the said part. As illustrated in FIG. 11A, even in the partial mold 120 constituting the third caulking die 103, three pressings are performed in the same manner as in the partial mold 120 constituting the first caulking die 101a described above. The surfaces 123a, 123b and 123c are formed on the molded surface 121, a recess 124a is formed between the adjacent pressing surfaces 123a and the pressing surface 123a, and a recess 124b is provided between the adjacent pressing surfaces 123b and the pressing surface 123c. However, each is provided.

11 (b) is a schematic cross-sectional view taken along the plane including the axis of the press type pipe joint represented by the lines DD of the partial die 120 illustrated in (a), and is clear from (a). It is a schematic cross-sectional view of the portion where the pressing surface 123c of the partial mold 120 is formed. Pressing surfaces 123c are formed on both sides of the annular groove portion 122 fitted to the annular bulging portion of the press type pipe joint (not shown) in the axial direction (double arrow of the broken line). Although not shown, the same applies to the portion of the partial mold 120 where the pressing surface 123b is formed and the portion where the pressing surface 123a is formed. Further, although not shown, the same applies to the other partial mold 110.

11 (c) is a schematic cross-sectional view taken along the plane including the axis of the press type pipe joint represented by the lines EE of the partial die 120 exemplified in (a), and is clear from (a). It is a schematic cross-sectional view of the portion provided with the recess 124a of the partial mold 120. Recesses 124a are formed on both sides of the annular groove portion 122 that fits into the annular bulging portion of the press type pipe joint (not shown) in the axial direction (double arrow of the broken line). Further, at the inner end of the recess 124a in the axial direction of the press type pipe joint, the depth of the recess 124a becomes shallower toward the inside (see the portion surrounded by the thick broken line). That is, a gradual change portion is provided at the inner end of the recess 124a. Although not shown, the same applies to the portion of the partial mold 120 provided with the recess 124b. Further, although not shown, the same applies to the other partial mold 110.

The configuration of the gradual change portion (for example, change pattern of shape, size and depth, etc.) is, for example, the mechanical strength, hardness, and third caulking mold of the material constituting the press type pipe joint and the piping element. Depending on various factors such as the coefficient of friction with the molded surface and the plastic working characteristics, it can be appropriately determined so that the desired effect of suppressing the remaining portion (knob portion) is achieved. For example, the gradual change portion may be formed of a flat surface or a curved surface as long as the above-mentioned requirements are satisfied. Further, the gradual change portion may be composed of a combination of a flat surface and / or a curved surface.

<effect>
As described above, in the third caulking die, a gradual change portion is provided at the inner end portion in the axial direction of the press-type pipe joint of the recess, and the depth in the radial direction of the press-type pipe joint of the recess is provided. It becomes shallower toward the inside in the axial direction of the press type pipe joint. By providing the gradual change portion at the inner end of the recess in this way, the portion near the inner end of the recess is formed in the process of reducing the diameter of the reduced diameter portion as compared with the case where the gradual change portion is not provided. It is possible to increase the possibility of contacting the press type pipe joint and pressing the press type pipe joint. Further, in the process of reducing the diameter of the reduced diameter portion, the portion in the vicinity of the inner end portion of the concave portion comes into contact with the press type pipe joint, so that the degree of division due to the concave portion of the molded surface described above is reduced. As a result, in the process of reducing the diameter of the annular bulge, the stress of pulling the material constituting the annular bulge acts more evenly over the entire circumference of the annular groove, and the annular bulge becomes more uniform and annular. The diameter can be reduced.

Although the gradual change portion is also drawn in FIGS. 1 to 4 and 10 referred to in the above-mentioned description of the first caulking die 101a and the second caulking metal fitting 102, the first caulking die and the second caulking die For metal fittings, the gradual change part is not an essential component.

<< Fourth Embodiment >>
Hereinafter, the press caulking die according to the fourth embodiment of the present invention (hereinafter, may be referred to as a “fourth caulking die”) will be described.

As described above, in each of the partial dies constituting the first caulking die to the third caulking die, the contact area between the molded surface and the contracted diameter portion is provided by the recess provided between the adjacent pressing surfaces. By reducing and / or alleviating the strain associated with the diameter reduction of the diameter-reduced portion, the formation of a surplus portion (knob portion) is suppressed, and the press-type pipe joint and the piping element are reliably airtight or liquid-tight. Can be connected to. From the viewpoint of further suppressing the formation of the surplus portion (knob portion) on the mating surface of the partial mold (divided surface of the caulking mold), it is desirable to reduce the friction coefficient between the molded surface and the reduced diameter portion. As a specific means for reducing the friction coefficient between the molded surface and the reduced diameter portion, for example, a film having a low friction coefficient with respect to the material constituting the reduced diameter portion is formed on the molded surface. Can be mentioned.

<Constitution>
Therefore, the fourth caulking die is any one of the above-mentioned first caulking die to the third caulking die, and is characterized in that a titanium nitride layer is formed on at least a part of the molded surface. It is a press caulking die. The titanium carbonitride (TiCN) layer is a ceramic coating with high hardness, low coefficient of friction and strong adhesion, and by forming it on at least a part of the molded surface, the coefficient of friction between the molded surface and the reduced diameter portion can be reduced. Can be reduced.

The titanium nitride (TiCN) layer may be formed on the entire surface of the molding surface of the partial mold constituting the fourth caulking die, or may be formed only on a part of the molding surface (for example, a pressing surface). May be. The method for forming the titanium nitride layer on at least a part of the molded surface is not particularly limited, and specific examples thereof include PVD method (physical vapor deposition method) and CVD method (chemical vapor deposition method). Can be mentioned.

<effect>
As described above, in the fourth caulking die, since the titanium nitride layer is formed on at least a part of the molded surface, the coefficient of friction between the molded surface and the reduced diameter portion can be reduced. Therefore, according to the fourth caulking die, the formation of the surplus portion (knob portion) on the mating surface (divided surface of the caulking die) of the partial die is further effectively suppressed, and the press type pipe joint and the piping element are further suppressed. It can be reliably connected airtightly or liquidtightly.

<< Fifth Embodiment >>
Hereinafter, the press caulking die according to the fifth embodiment of the present invention (hereinafter, may be referred to as “fifth caulking die”) will be described with reference to the drawings.

As described above, in each of the partial dies constituting the first caulking die to the fourth caulking die, the contact area between the molded surface and the contracted diameter portion is provided by the recess provided between the adjacent pressing surfaces. By reducing and / or alleviating the strain associated with the diameter reduction of the diameter-reduced portion, the formation of a surplus portion (knob portion) is suppressed, and the press-type pipe joint and the piping element are reliably airtight or liquid-tight. Can be connected to.

Further, as in the case of the press caulking die (conventional caulking die) according to the above-mentioned conventional technique, a reduced diameter portion (hexagonal cross-sectional reduced diameter portion) having a substantially hexagonal cross section is formed on both sides or one side of the annular bulging portion. Therefore, the occurrence of relative movement (for example, indexing and / or disconnection) between the press type pipe joint and the pipe element is also reduced.

However, depending on the application of the press-type pipe joint, the press-type pipe joint and the piping element are more firmly fixed and connected to more reliably cause relative movement (for example, indexing and / or disconnection) between the two. May be required to be reduced.

<Constitution>
Therefore, the fifth caulking die is any one of the above-mentioned first caulking dies to the fourth caulking dies, and protrusions protruding inward in the radial direction of the press type pipe joint are formed on at least one pressing surface. It is a press caulking die characterized by being made.

FIG. 12 is a schematic diagram showing an example of the configuration of one of the pair of partial dies constituting the fifth caulking die. Specifically, FIG. 12A is a schematic front view of the partial mold 110 included in the fifth caulking mold 105, and FIG. 12B is a portion where the pressing surface 113c of the partial mold 110 is formed. It is a schematic cross-sectional view of, (c) is a schematic plan view when the partial mold 110 exemplified in (a) and (b) is observed from the division surface side. However, in (c), the reference numerals of the recesses are omitted, and the reference numerals of the pressing surfaces 113a, 113b and 113c and the protrusions 116 formed on these pressing surfaces are in the axial direction of the press type pipe joint (not shown). It is attached only to one of the positions facing each other with the annular groove portion 112 interposed therebetween.

As illustrated in FIG. 12A, even in the partial mold 110 constituting the fifth caulking die 105, three pressings are performed in the same manner as in the partial mold 110 constituting the first caulking die 101a described above. The surfaces 113a, 113b and 113c are formed on the molded surface 111, a recess 114a is formed between the adjacent pressing surface 113a and the pressing surface 113a, and a recess 114b is provided between the adjacent pressing surface 113b and the pressing surface 113c. However, each is provided. In addition, one protrusion 116 that protrudes inward in the radial direction of the press type pipe joint (not shown) is formed on each of the three pressing surfaces 113a, 113b and 113c.

Further, FIG. 12B is a schematic cross-sectional view taken along a plane including the shaft of the press type pipe joint represented by the line FF of the partial die 110 exemplified in FIG. 12A. As is clear from the above, it is a schematic cross-sectional view of the portion where the pressing surface 113c of the partial mold 110 is formed. Pressing surfaces 113c are formed on both sides of the annular groove portion 112 fitted to the annular bulging portion of the press type pipe joint (not shown) in the axial direction (double arrow of the broken line). In addition, one protrusion 116 that protrudes inward in the radial direction of the press type pipe joint is formed on each of these two pressing surfaces 113c. Although not shown, the same applies to the portion of the partial mold 110 where the pressing surface 113b is formed and the portion where the pressing surface 113a is formed.

Further, as illustrated in FIG. 12 (c), in the partial die 110 constituting the fifth caulking die 105, positions facing each other across the annular groove portion 122 in the axial direction of the press type pipe joint (not shown). Three pressing surfaces 113a, 113b and 113c are formed on the surface, respectively. In addition, one protrusion 116 that protrudes inward in the radial direction of the press type pipe joint (not shown) is formed on the pressing surfaces 113a, 113b, and 113c, respectively.

Although the drawing corresponding to FIG. 12 of the other partial mold 120 of the fifth caulking mold 105 is omitted, the partial mold 120 also has the same configuration as the above-mentioned partial mold 110.

The configuration of the protrusions formed on the pressing surface (for example, the shape, size, height, the number of protrusions formed on one pressing surface, etc.) is, for example, the material constituting the press type pipe joint and the piping element. It is appropriately determined according to various factors such as the mechanical strength and hardness of the press type pipe joint, the friction coefficient between the press type pipe joint and the pipe element, and the connection strength between the press type pipe joint and the pipe element required in the application of the press type pipe joint. be able to. Further, the number of pressing surfaces on which the protrusions are formed and the positions where the protrusions are formed on the pressing surfaces can be appropriately determined according to various factors as described above. From the viewpoint of alleviating the strain caused by the diameter reduction of the diameter-reduced portion even in the recess, it is desirable to form the protrusion at a position as far as possible from the recess. Specifically, it is desirable to form a protrusion at or near the center of the pressing surface.

<effect>
As described above, in the fifth caulking die, protrusions protruding inward in the radial direction of the press type pipe joint are formed on at least one pressing surface. The protrusions formed on the pressing surface in this way press the reduced diameter portion more locally and deeper in the process of reducing the diameter of the reduced diameter portion. As a result, according to the fifth caulking die, the press-type pipe joint and the piping element are more firmly fixed and connected, and relative movement (for example, indexing and / or disconnection) between the two is more likely to occur. It can be surely reduced.

As described above, for the purpose of explaining the present invention, some embodiments having a specific configuration have been described with reference to the accompanying drawings at times, but the scope of the present invention is limited to these exemplary embodiments. It should not be construed as being limited, and it goes without saying that amendments can be made as appropriate within the scope of the claims and the matters described in the specification.

101a, 101b, 102, 103, 105 ... Press caulking dies 110, 120, 130 ... Partial dies 111, 121 ... Molding surfaces 113a, 113b, 113c, 123a, 123b, 123c ... Pressing surfaces 114a, 114b, 124a, 124b ... Concave part 115 ... Inclined part 116 ... Protrusion 210, 211,212 ... Piping element 220 ... Press type pipe joint 221 ... Socket part 222 ... Circular bulge part 230 ... Seal member (O-ring)

Claims (5)

An annular groove, which is an annular recess having a shape corresponding to an annular bulge of a press-type pipe fitting,
It is arranged around the axis of the press-type pipe joint so as to surround the contracted diameter portion which is a portion of the press-type pipe joint located on both sides or one side of the annular bulge portion in the axial direction of the press-type pipe joint. The pressing surface, which is six planes facing the contracted diameter portion,
With a molded surface on which
It is configured to reduce the diameter of the reduced diameter portion by pressing the contracted diameter portion with the pressing surface.
It is a press caulking die,
The press caulking die is divided into two or three partial dies around the axis of the press type pipe joint.
When the press caulking die is divided into two said partial dies, each said partial die has three said pressing surfaces.
When the press caulking die is divided into three said partial dies, each said partial die has two said pressing surfaces.
In each of the partial molds, at the corner portion which is a portion between the adjacent pressing surfaces, both or one of the virtual pressing surfaces which are two planes obtained by extending the adjacent pressing surfaces respectively. A recess is provided that defines a space extending outward in the radial direction of the press-type pipe joint.
A press caulking die that is characterized by this. The press caulking die according to claim 1.
Both ends of the molded surface of the partial die in the circumferential direction move away from the shaft of the press-type pipe joint toward both ends in the axial direction of the press-type pipe joint toward the ends in the axial direction of the press-type pipe joint. There is an inclined part that is an inclined part like this,
A press caulking die that is characterized by this. The press caulking die according to claim 1 or 2.
At the inner end of the recess in the axial direction of the press-type pipe joint, the depth of the recess in the radial direction of the press-type pipe joint becomes shallower toward the inside in the axial direction of the press-type pipe joint. There is a gradual change part,
A press caulking die that is characterized by this. The press caulking die according to any one of claims 1 to 3.
A titanium nitride layer is formed on at least a part of the molded surface.
A press caulking die that is characterized by this. The press caulking die according to any one of claims 1 to 4.
A protrusion protruding inward in the radial direction of the press type pipe joint is formed on at least one pressing surface.
A press caulking die that is characterized by this.

Images