JP2005090629A - Ball joint for piping - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball joint for piping, capable of maintaining its movability even under high pressure. <P>SOLUTION: This ball joint comprises a shaft member 100 having a ball part 110, and a bearing member 200 having a bearing surface matched to the ball part 110. The shaft member 100 comprises an axial center flow passage forming part 120, and a first communication flow passage 112 from the center of the ball part 110 to the surface of the ball part. In the surface of the ball part 110, two seal grooves 114 and 116 are provided at offset positions at equal distance on the opposite side from each other having a large circle having openings of the communication flow passage 112 between them. The bearing member 200 comprises communication grooves 212 provided along the large circle in the surface of the ball part to communicate with the communication flow passage 112, and a second communication flow passage 226 to communicate the communication groove 212 with an external flow passage. The bearing member 200 further has a release hole 222 provided at a position of the surface of the ball part on the opposite side to the side of the axial center flow passage 122 in the ball part 110 to communicate with open air. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a ball joint for piping, and more particularly to a ball joint suitable for high pressure.

  As a ball joint for piping, for example, those described in the following patent documents are known.

Japanese Patent Application Publication No. 2002-2002

  However, the conventional ball joint has a problem that when the fluid pressure is increased, the ball is pressed in the direction in which the ball is pulled out.

  An object of this invention is to provide the ball joint for piping which can maintain easiness of movement even at a high pressure.

In order to achieve the above object, the ball joint for piping of the present invention comprises:
A shaft member having a ball portion;
A bearing member having a bearing surface adapted to the ball portion;
With
The shaft member is
An axial flow path extending from one end of the shaft member to the center of the ball portion;
A first communication channel from the center of the ball part to the surface of the ball part along a direction perpendicular to the direction of the axial channel;
With
When the ball portion assumes a great circle defined by an intersection of a plane including the direction of the first communication flow path and perpendicular to the direction of the axial flow path, and the surface of the ball portion, the great circle is First and second seal grooves provided at positions offset by equal distances on opposite sides of each other, and each of the first and second seal grooves goes around the ball portion surface along a small circle parallel to the great circle. And a second seal groove,
The bearing member is
A communication groove provided along the great circle on the surface of the ball portion and communicating with the first communication channel;
A second communication channel for communicating the communication groove and an external channel connected to the bearing member;
A release hole which is provided at a position on the surface of the ball portion opposite to the side where the axial flow path of the shaft member exists in the ball portion, and communicates with outside air;
Have

  According to this ball joint, the axial flow path side and the release hole side of the ball portion are released to the atmosphere, and fluid pressure is applied to the portion located in the communication groove between them. Therefore, even if the fluid pressure increases, the ball is not pressurized in the direction in which the ball comes out, and the ease of movement can be maintained even when the pressure is increased.

  The first communication channel may be formed in a radial shape so as to have openings that are arranged uniformly along the great circle on the surface of the ball portion.

  According to this configuration, even if the axis is tilted, one of the openings is released to the communication groove. Therefore, there is an advantage that the width of the communication groove can be reduced and the inclination angle of the joint can be increased.

The ball portion has a wrench hole at a position facing the release hole of the bearing member;
The release hole may have a size capable of inserting a wrench that matches the wrench hole.

  According to this configuration, the ball portion can be held in a state where the wrench is inserted into the wrench hole of the ball portion, so that the joint can be easily handled.

The bearing member is
A first member having a hole in a portion through which the axial flow path of the shaft member passes;
A second member having the release hole;
With
The first and second members each have a threaded portion for screwing together;
The release hole may be formed as a wrench hole.

  According to this configuration, since the bearing member can be assembled by screwing the first and second members, the assembly is easy.

The bearing member includes two bearing surfaces,
One shaft member may be coupled to each bearing surface.

  According to this configuration, since two shaft members are coupled, there is an advantage that the degree of freedom in rotating the shaft member is greater.

A-1. First embodiment:
FIG. 1 is a cross-sectional view of a main part showing a ball joint according to a first embodiment of the present invention. This ball joint includes a shaft member 100 having a ball portion 110 and a bearing member 200.

  In addition to the ball part 110, the shaft member 100 has an axial center flow path forming part 120 formed integrally with the ball part 110. The axial flow path forming part 120 has a polygonal part 124 having an outer diameter formed in a polygonal shape, and an external pipe connecting part 126 having a threaded part formed on the outer periphery. At the center of the axial flow path forming part 120, a linear axial flow path 122 that reaches the center of the ball of the ball part 110 is provided. Inside the ball part 110, communication channels 112 are provided radially along a direction that passes through the center of the ball of the ball unit 110 and is perpendicular to the axial center channel 122. In the present embodiment, the communication flow path 112 has a cross shape and has openings at four locations on the great circle on the surface of the ball portion 110. Although the number of the communication channels 112 is arbitrary, it is preferable that the communication channels 112 are provided radially so as to have openings uniformly along the great circle on the surface of the ball portion 110. This is because when the shaft member 100 is tilted, one of the openings is released with respect to the communication groove 212 (also referred to as a communication path) so that the width of the communication groove 212 can be reduced. This is to make it possible to design.

  A great circle in which a plurality of openings of the communication channel 112 are arranged can be assumed on the surface of the ball portion 110. In the following description, “great circle” or “large circle of the ball portion 110” means this great circle unless otherwise specified.

  Two O-ring grooves 114 and 116 are provided on the surface of the ball part 110 at positions offset by equal distances on opposite sides of the great circle of the ball part 110. These O-ring grooves 114 and 116 each circulate around the surface of the ball portion 110 along a small circle parallel to the great circle of the ball portion 110. O-rings are fitted in these O-ring grooves 114 and 116, and seal with the inner surface of the bearing member 200.

  The bearing member 200 includes a first member 210 closer to the axial center flow path forming portion 120 than the great circle of the ball portion 110, and a second member 220 on the opposite side. In the first embodiment, these two members 210 and 220 are joined to each other by welding with the ball portion 110 inserted therebetween. In the joined state, the inner surfaces of the two members 210 and 220 form a spherical surface that conforms to the surface of the ball portion 110. The inner surface of the first member 210 functions as an O-ring sealing surface of the first O-ring groove 114, and the inner surface of the second member 220 is an O-ring sealing surface of the second O-ring groove 116. Function as. The first member 210 is provided with a communication groove 212 at a position along the great circle of the ball portion 110 when the shaft member 100 is in an upright state (not tilted). In the present embodiment, the communication groove 212 extends over the entire circumference of the great circle, but the communication groove 212 may be provided only in a part of the great circle.

  The second member 220 of the bearing member 200 has a release that communicates with the outside air at a position on the surface of the ball portion opposite to the side on which the axial flow path forming portion 120 is provided on the surface of the ball portion 110. A hole 222 is provided. The second member 220 further has an external pipe connection part 224 for connecting to the external pipe 330, and communicates the communication groove 212 of the first member 210 and the flow path of the external pipe 330. For this purpose, a communication channel 226 is provided.

  The external pipe connection part 126 of the shaft member 100 is configured as a hollow male screw part, and is connected to the external pipe 310 by the nut part 300. The nut portion 300 is fitted on the outer periphery of the external pipe 310 together with the two taper rings 302 and 304 therein. When the nut part 300 is screwed into the external pipe connection part 126 in this state, the taper rings 302 and 304 bite into the external pipe 310, thereby ensuring the sealing performance. The polygonal part 124 of the axial flow path forming part 120 is for holding the axial flow path forming part 120 when the nut part 300 is screwed. Similarly, the external piping 330 is connected to the external piping connection portion 224 of the bearing member 200 by the nut portion 320. However, any method and configuration other than this can be adopted as a connection method and configuration with external piping.

  By the way, assuming a complete spherical surface including the surface of the ball portion 110, this complete spherical surface is divided into three regions by two planes defined by the positions of the O-ring grooves 114 and 116 as shown in FIG. R1, R2, and R3 are classified. The first region R1 is an axial channel passage region through which the axial channel 122 passes. The second region R2 is a communication region where the communication channel 112 and the communication groove 212 exist. The third region R3 is a release region where the release hole 222 exists. The axial center passage passage region R1 and the release region R3 are both released to the atmosphere. On the other hand, the communication region R2 is maintained at a fluid pressure.

  Since this ball joint is sealed between the surface of the ball part 110 and the inner surface of the bearing member 200, the ball joint can freely rotate within a range in which the shaft center flow path forming part 120 does not interfere with the bearing member 200. Further, since the release hole 222 is provided in the release region R3 of the ball part 110, fluid pressure is not applied to the release region R3. Therefore, in this ball joint, it can be understood that fluid pressure is applied only to the communication region R2, and atmospheric pressure is equally applied to the regions R1, R3 on both sides thereof. If there is no release hole 222, if the fluid leaks to the region R3, the fluid pressure is applied to the region R3, so that the pressure applied to the communication region R2 may not be equalized. In the ball joint of the first embodiment, such an uneven pressure is not generated, so that no force is applied in the direction in which the ball portion 110 is pulled out. As a result, it is possible to maintain the ease of movement of the ball part 110 even at a high pressure.

  Further, in this ball joint, no force is applied in the direction in which the ball portion 110 is pulled out, so that the shaft member 100 and the bearing member 200 do not need to be excessively large even when used as a joint for high-pressure piping. Therefore, it is possible to keep the joint installation space small.

  In this embodiment, the members other than the O-ring are made of metal, for example, made of stainless steel. At this time, if the inner diameter of the flow path is about 2 mm and the outer diameter of the external pipes 310 and 330 is about 10 mm, a pressure resistance of 35 MPa to 70 MPa can be achieved. Such a ball joint can be used as a joint for high-pressure hydrogen piping, for example.

A-2. Second embodiment:
FIG. 2 is a cross-sectional view of an essential part showing a ball joint in the second embodiment. The ball joint of the second embodiment is different from the first embodiment (FIG. 1) only in the bearing member 200a, and the shaft member 100 is the same as that of the first embodiment.

  The first member 210a of the bearing member 200a of the second embodiment has an external pipe connection portion 216. The external pipe connection portion 216 is provided in a direction perpendicular to the upright shaft member 100. In addition to the communication groove 212a, a communication channel 214 that communicates with external piping is also provided on the inner surface of the first member 210a. On the other hand, the second member 220a is only provided with a release hole 222a, and is not provided with the communication flow path 226 or the external pipe connection portion 224 as in the first embodiment.

  Similarly to the ball joint of the first embodiment, the ball joint of the second embodiment can maintain the ease of movement of the joint portion at high pressure.

A-3. Third embodiment:
FIG. 3 is a cross-sectional view of an essential part showing a ball joint in the third embodiment. The ball joint of the third embodiment is different from the second embodiment (FIG. 2) only in the ball portion 110b and the second member 220b of the bearing member 200b, and the other configurations are the same as those of the second embodiment.

  The second member 220b of the bearing member 220b is provided with a larger release hole 222b than in the second embodiment. The ball portion 110b is provided with a wrench hole 118 smaller than the release hole 222b at a position corresponding to the release hole 222b. Therefore, by inserting a wrench from the release hole 222b into the wrench hole 118, the nut portion 300 can be fitted into the shaft member 100b while suppressing the rotation of the ball portion 110b. In this embodiment, since the rotation of the ball part 110b can be directly suppressed with a wrench, the polygonal part 124 on the axial center channel side may be omitted. Also, the ball joint of the third embodiment has the same effect as the ball joint of the first and second embodiments.

A-4. Fourth embodiment:
FIG. 4 is a cross-sectional view of an essential part showing a ball joint in the fourth embodiment. The ball joint of the fourth embodiment is different from the second embodiment (FIG. 2) only in the shaft center flow path forming portion 120d of the shaft member 100d, and the other configuration is the same as that of the second embodiment.

  The axial flow path forming part 120d of the third embodiment has a polygonal part 124d and a taper threaded part 126d for connecting to external piping. In this configuration, a female screw is provided on the external piping side. The ball joint of the fourth embodiment has the same effect as the ball joints of the other embodiments described above.

A-5. Example 5:
FIG. 5 is a cross-sectional view of an essential part showing a ball joint in the fifth embodiment. The ball joint of the fifth embodiment is the same as the fourth embodiment except for the bearing member 200e, which is different from the fourth embodiment (FIG. 4).

  The two members 210e and 220e constituting the bearing member 200e of the fifth embodiment respectively have screw portions for screwing together, and in this respect, the second embodiment (FIG. 2) and the fourth embodiment This is different from the two members 210a and 220a of the embodiment (FIG. 4). The release hole 222e of the second member 220e is formed as a wrench hole having a polygonal shape. The release hole 222e is used as a wrench hole when the second 220e is screwed into the first member 210e.

  The ball joint of the fifth embodiment has the same effect as the ball joints of the other embodiments described above. Moreover, since it is not necessary to weld when assembling the bearing member 200e, there exists an advantage that an assembly is easy.

A-6. Example 6:
FIG. 6 is a cross-sectional view of an essential part showing a ball joint in the sixth embodiment. The ball joint of the sixth embodiment is different from the fifth embodiment (FIG. 5) only in the shaft member 100f, and the other configuration is the same as that of the fifth embodiment.

  The ball portion 110f of the sixth embodiment is provided with the same wrench hole 118 as that of the third embodiment (FIG. 3). When connecting to the external piping, the rotation of the shaft member 100f can be suppressed by the wrench inserted into the wrench hole 118, so that the polygonal portion 124d as shown in FIG. 4 is not necessary. The ball joint of the sixth embodiment has the same effect as the ball joint of the fifth embodiment described above. Further, there is an advantage that the member for preventing rotation of the shaft member 100f is smaller than that of the fourth embodiment.

A-7. Seventh embodiment:
FIG. 7 is a cross-sectional view of an essential part showing a ball joint in the seventh embodiment. The ball joint of the seventh embodiment is different from the sixth embodiment (FIG. 6) only in that the shaft member 100g is the same as the sixth embodiment.

  The shaft member 100g of the seventh embodiment does not have an axial flow path forming portion, and the shaft member 100g is configured by only the ball portion 100g. That is, a female screw portion 122g is formed on the left side of the ball portion 110g in FIG. The female screw portion 122g is a taper screw, and the external screw of the external pipe is directly screwed into the female screw portion 122g. In addition, the internal thread part 122g of a present Example functions also as an axial center flow path to the center of the ball | bowl part 110g.

  The ball joint of the seventh embodiment has the same effect as the ball joint of the sixth embodiment described above. Further, since the external piping is directly screwed into the ball portion 110g, there is an advantage that the entire joint is further reduced.

A-8. Example 8:
FIG. 8 is a cross-sectional view of the main part showing the ball joint in the eighth embodiment. The ball joint of the eighth embodiment is different from the sixth embodiment (FIG. 6) and the seventh embodiment (FIG. 7) only in the shaft member 100h, and other configurations are the same as those of the sixth and seventh embodiments. is there.

  A non-tapered female screw portion 122h is formed on the left side of the ball portion 110h of the eighth embodiment. The female screw portion 122h is screwed with a male screw portion 410 provided on the tank wall surface 400. An O-ring 420 is provided at the root of the male screw portion 410 of the wall surface 400. A cut surface 111 that functions as a seal surface of the O-ring 420 is formed around the opening of the female screw portion 122h of the ball portion 110h.

  When screwing the screw parts 122h and 410, a wrench is inserted into a wrench hole 118 provided on the opposite side of the ball part 110h, and the ball part 110h is rotated. When the screwing is complete, a seal is achieved between the O-ring 420 and the cut surface 111. The ball joint of the eighth embodiment also has the same effect as the ball joint of the seventh embodiment described above.

A-9. Ninth embodiment:
FIG. 9 is a cross-sectional view of an essential part showing a ball joint in the ninth embodiment. The ball joint of the ninth embodiment has a structure in which the bearing member 200j has two bearing surfaces, and the shaft members 100 are respectively coupled to the two bearing surfaces. As understood from comparison with FIG. 1, the ball joint of the ninth embodiment is obtained by cutting the ball joint of the first embodiment at a position of the release hole 222 in a plane perpendicular to the paper surface and inverting it. It has a combined mirror symmetry structure. More specifically, the bearing member 200j includes three members 210j, 220j, and 230j. The first member 210j is the same as the first member 210 shown in FIG. The third member 230j has a structure obtained by inverting the first member 210j. The second member 220j has a mirror-symmetric structure having a release hole 222j in the center and a communication channel 226j that communicates with the communication grooves 212j and 232j of the first and third members 210j and 220j. The release hole 222j simultaneously releases the surfaces of the left and right ball portions 110 to the atmosphere.

  Similarly to the ball joint of the first embodiment, the ball joint of the ninth embodiment can maintain the ease of movement of the joint portion at high pressure. Further, since both the two shaft members 100 can freely rotate within a certain range, there is an advantage that the degree of freedom of rotation is further increased.

A-10. Tenth embodiment:
FIG. 10 is a cross-sectional view of the main part showing the ball joint in the tenth embodiment. The ball joint of the tenth embodiment is different from the ninth embodiment in that the bearing member 200k is screwed, and the other points are the same as the ninth embodiment.

  The bearing member 200k is composed of four members 210k, 220k, 230k, and 240k. The first member 210k corresponds to the first member 210j in FIG. 9, and a communication groove 212k is formed along the circumference of the great circle of the ball portion 110 of the first shaft member 100 illustrated on the left side. Has been. A male screw portion 218 is formed on the outer periphery of the first member 210k. The second member 220k corresponds to the second member 220j of FIG. 9, and is provided with a release hole 222k for simultaneously releasing the surfaces of the ball portions 110 of the two left and right shaft members 100 to the atmosphere. . The third member 230k corresponds to the third member 230j in FIG. 9, and a communication groove 232k is formed along the circumference of the great circle of the ball portion 110 of the second shaft member 100 on the right side. Yes. The communication groove 232k communicates with the communication groove 212k of the first member 210k by a communication flow path 226k provided in the second member 220k. An engagement protrusion 238 is further formed on the outer periphery of the third member 230k. The inner surface of the fourth member 240k is formed with an engagement protrusion 244 that engages with the engagement protrusion 238 of the third member 230k, and an internal thread portion 246 that engages with the external thread portion 218 of the first member 210k. Yes. Accordingly, when the fourth member 240k and the first member 210k are screwed together, the four members are fixed in a state where the first member 210k and the third member 230k have bite into the second member 220k. The fourth member 240k is also provided with a release hole 242k that releases the release hole 222k of the second member 220k to the outside air.

  The ball joint of the tenth embodiment has the same effect as the ball joint of the ninth embodiment. Further, the tenth embodiment has an advantage that the assembly is easy because it is not necessary to weld the bearing member 200k when assembling.

  In addition, this invention is not restricted to said Example and embodiment, In the range which does not deviate from the summary, it is possible to implement in various aspects.

The principal part sectional view showing the ball joint of the 1st example. Sectional drawing which shows the principal part which shows the ball joint of 2nd Example. Sectional drawing which shows the principal part which shows the ball joint of 3rd Example. Sectional drawing which shows the principal part which shows the ball joint of 4th Example. Sectional drawing which shows the principal part which shows the ball joint of 5th Example. Sectional drawing which shows the principal part which shows the ball joint of 6th Example. Sectional drawing which shows the principal part which shows the ball joint of 7th Example. Sectional drawing which shows the principal part which shows the ball joint of 8th Example. Sectional drawing which shows the principal part which shows the ball joint of 9th Example. Sectional drawing which shows the principal part which shows the ball joint of 10th Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Shaft member 110 ... Ball part 111 ... Cut surface 112 ... Communication flow path 114, 116 ... O-ring groove (seal groove)
118 ... Wrench hole 120 ... Axial flow path forming part 122 ... Axial flow path 122g ... Female thread part 122h ... Female thread part 124 ... Polygonal part 126 ... External piping connection part 126d ... Tapered screw part 200 ... Bearing member 210 ... First 212 ... Communication groove 214 ... Communication flow path 216 ... External pipe connection part 218 ... Male thread part 220 ... Second member 222 ... Release hole 224 ... External pipe connection part 226 ... Communication flow path 230j, k ... Third member 232k ... Communication groove 238 ... engagement projection 240k ... fourth member 242k ... release hole 244 ... engagement projection 246 ... female screw portion 300 ... nut portion 302, 304 ... taper ring 310 ... external piping 320 ... nut portion 330 ... external piping 400 ... Tank wall surface 410 ... Male thread 420 ... O-ring R1 ... Axis flow path passage region R2 ... Communication region R3 ... Release region

Claims (5)

A ball joint for piping,
A shaft member having a ball portion;
A bearing member having a bearing surface adapted to the ball portion;
With
The shaft member is
An axial flow path extending from one end of the shaft member to the center of the ball portion;
A first communication channel from the center of the ball part to the surface of the ball part along a direction perpendicular to the direction of the axial channel;
With
When the ball portion assumes a great circle defined by an intersection of a plane including the direction of the first communication flow path and perpendicular to the direction of the axial flow path, and the surface of the ball portion, the great circle is First and second seal grooves provided at positions offset by equal distances on opposite sides of each other, and each of the first and second seal grooves goes around the ball portion surface along a small circle parallel to the great circle. And a second seal groove,
The bearing member is
A communication groove provided along the great circle on the surface of the ball portion and communicating with the first communication channel;
A second communication channel for communicating the communication groove and an external channel connected to the bearing member;
A release hole which is provided at a position on the surface of the ball portion opposite to the side where the axial flow path of the shaft member exists in the ball portion, and communicates with outside air;
Having a ball joint for piping. A piping ball joint according to claim 1,
The piping ball joint, wherein the first communication flow path is formed radially so as to have openings uniformly arranged along the great circle on the surface of the ball portion. A piping ball joint according to claim 1 or 2,
The ball portion has a wrench hole at a position facing the release hole of the bearing member;
The release hole is a ball joint for piping having a size capable of inserting a wrench adapted to the wrench hole. A piping ball joint according to claim 1 or 2,
The bearing member is
A first member having a hole in a portion through which the axial flow path of the shaft member passes;
A second member having the release hole;
With
The first and second members each have a threaded portion for screwing together;
The release hole is a ball joint for piping formed as a wrench hole. A piping ball joint according to claim 1 or 2,
The bearing member includes two bearing surfaces,
A ball joint for piping, in which each of the shaft members is coupled to each bearing surface.

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