Pipe connection structure

Abstract

To provide a pipe connection structure capable of performing flow path connection with high accuracy.SOLUTION: A pipe connection structure, in which a pipe is fluidly connected to a port by inserting a tip part of the pipe to a predetermined position in the port, comprises a pressing structure that contacts an outer peripheral surface of the tip part of the pipe inserted to the predetermined position in the port and generates the pressing force on the outer peripheral surface of the tip part of the pipe toward the center of the port. When the tip part of the pipe is inserted to the predetermined position in the port, the pressing force generated by the pressing structure causes the center of the tip part of the pipe to substantially coincide with the center of the port.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pipe connection structure for fluidly connecting a pipe to a port. [Background technology]

[0002] A liquid chromatograph (hereinafter referred to as LC) generally comprises a liquid delivery pump, an autosampler, a separation column, and a detector. Each module is connected by piping. As a result, the mobile phase delivered by the liquid delivery pump is mixed with the sample to be analyzed, which is injected by the autosampler. The components in the sample are separated from each other by the separation column, and the separated components are sequentially detected by the detector (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-067413 Summary of the Invention [Problem to be solved by the invention]

[0004] In LC, the flow rate of the mobile phase affects the analytical results, so the accuracy of the mobile phase flow rate is important. In particular, in nano- and micro-LC, where the diameter of the flow channel is less than 100 μm, with the smallest being around 10-20 μm, even a slight misalignment or leak at the connection part of the flow channel can have a significant effect on the analytical results, so the flow channel connections must be made with high precision.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a pipe connection structure that allows for highly accurate connection of flow paths. [Means for solving the problem]

[0006] In a typical pipe connection structure that connects a pipe to a port using a ferrule and a nut, the inner diameter of a predetermined position within the port is slightly larger than the outer diameter of the pipe's tip to allow the pipe's tip to be inserted into or removed from the port, and a gap exists between the inner surface of the port at the predetermined position and the outer circumferential surface of the pipe's tip. As a result, the pipe may be fixed to the port with the center of the pipe's tip misaligned with the center of the port. If the center of the pipe's tip is misaligned with the center of the port, the pipe's internal flow path may be misaligned with the internal flow path of the port, potentially hindering the flow of fluid within the port. Therefore, in a first embodiment of the pipe connection structure according to the present invention, a pressing structure is provided at the connection portion of the pipe to the port, which generates a pressing force to move the center of the pipe's tip toward the center of the port.

[0007] That is, the first embodiment of the pipe connection structure according to the present invention is as follows: A pipe connection structure in which a tip end of a pipe is inserted into a port to a predetermined position, thereby fluidly connecting the pipe to the port, a pressing structure that comes into contact with an outer peripheral surface of the tip end portion of the pipe that has been inserted to the predetermined position in the port and generates a pressing force on the outer peripheral surface of the tip end portion of the pipe toward the center of the port, The pressure structure is configured to generate a pressing force when the tip of the piping is inserted to the predetermined position in the port, so that the center of the tip of the piping and the center of the port are approximately aligned.

[0008] In addition, as a structure for connecting a pipe to a port, in addition to a structure in which a ferrule is attached to the tip of the pipe and pressed against the port to maintain a liquid-tight connection, there is also a structure in which a seal member made of an elastic material is attached to the tip surface of the pipe and pressed against the innermost surface of the port to maintain a liquid-tight connection. In these structures, there is a risk that the ferrule or seal member may come into contact with other structures and be damaged when removing the pipe from the port. Damage to the ferrule or seal member can cause problems such as a decrease in sealing performance at the connection and sample retention during analysis. Therefore, in a second embodiment of the pipe connection structure according to the present invention, the seal member for maintaining a liquid-tight connection when connecting the pipe to the port is provided inside the port rather than at the tip of the pipe.

[0009] That is, the second embodiment of the pipe connection structure according to the present invention is as follows: A pipe connection structure in which a tip end of a pipe is inserted into a port to a predetermined position, thereby fluidly connecting the pipe to the port, The innermost surface of the port and the tip surface of the pipe are flat surfaces, a ring-shaped seal member made of an elastic material held on the innermost surface of the port; When the tip of the piping is inserted up to the specified position in the port, it is sandwiched between the innermost surface of the port and the tip surface of the piping, so that the internal flow paths of the piping and the port are fluidically connected in a liquid-tight manner. [Effects of the Invention]

[0010] A first embodiment of the pipe connection structure according to the present invention includes a pressing structure that contacts the outer peripheral surface of a tip of a pipe inserted to a predetermined position in a port and generates a pressing force on the outer peripheral surface of the tip of the pipe toward the center of the port, and is configured so that when the tip of the pipe is inserted to the predetermined position in the port, the pressing force generated by the pressing structure causes the center of the tip of the pipe and the center of the port to approximately coincide with each other, thereby suppressing misalignment between the center of the tip of the pipe and the center of the port. This provides a pipe connection structure that enables highly accurate fluid channel connection.

[0011] According to a second embodiment of the piping connection structure of the present invention, the innermost surface of the port and the tip surface of the piping are flat, and a ring-shaped seal member made of an elastic material is held on the innermost surface of the port, and when the tip end of the piping is inserted to the predetermined position in the port, it is sandwiched between the innermost surface of the port and the tip surface of the piping, thereby fluid-tightly connecting the internal flow paths of the piping and the port, thereby preventing damage to the seal member when the piping is removed from the port. This provides a piping connection structure that enables highly accurate flow path connection. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view showing a first embodiment of a pipe connection structure. [Figure 2] FIG. 4 is a cross-sectional view showing a second embodiment of the pipe connection structure. [Figure 3] FIG. 10 is a cross-sectional view showing a third embodiment of the pipe connection structure. [Figure 4] FIG. 10 is a plan view of a pressing structure portion of the third embodiment. [Figure 5] FIG. 10 is a cross-sectional view showing a fourth embodiment of the pipe connection structure. [Figure 6] FIG. 10 is a plan view of a pressing structure portion of the fourth embodiment. [Figure 7] FIG. 10 is a cross-sectional view showing a modified example of the first embodiment. [Figure 8]FIG. 10 is a cross-sectional view showing a modified example of the second embodiment. [Figure 9] FIG. 10 is a cross-sectional view showing a fifth embodiment of a pipe connection structure. [Figure 10] FIG. 10 is a cross-sectional view showing a sixth embodiment of a pipe connection structure. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of a pipe connection structure according to the present invention will be described with reference to the drawings.

[0014] A first embodiment of the pipe connection structure will be described with reference to FIG.

[0015] The piping connection structure of this embodiment is a structure in which a piping 100 is connected to a port 114 provided in a flow path block 112 .

[0016] Pipe 100 is passed through the inside of nut 110, and sleeve 102 is attached to the tip of pipe 100. The position of sleeve 102 is adjusted so that the tip surface is aligned with the tip surface of pipe 100. The inner diameter of nut 110 is smaller than the outer diameter of sleeve 102. A groove 104 is provided in the circumferential direction on the outer peripheral surface of sleeve 102, and a circular ring-shaped elastic member 106 is fitted into groove 104. A circular ring-shaped seal member 108 made of an elastic material is attached to the tip surfaces of pipe 100 and sleeve 102.

[0017] The elastic modulus of the seal member 108 may be smaller than the elastic modulus of the tip surface of the piping 100, the tip surface of the sleeve 102, and the innermost surface 118 of the port 114. For example, the tip surface of the piping 100, the tip surface of the sleeve 102, and the innermost surface 118 of the port 114 may be made of metal or ceramic, and the seal member 108 may be made of resin.

[0018] The outer diameter of the sleeve 102 is slightly smaller than the inner diameter of the innermost portion 120 of the port 114, and the outer diameter of the elastic member 106 is slightly larger than the inner diameter of the innermost portion 120 of the port 114. The sleeve 102 is made of resin or metal, and the elastic member 106 is made of an elastic resin such as polyether ether ketone (PEEK).

[0019] Elastic member 106 constitutes a pressing structure that presses the tip end of piping 100 toward the center of innermost portion 120 of port 114 when the tip end of piping 100, to which sleeve 102 is attached, is inserted up to innermost portion 120 of port 114. In other words, when the tip end of piping 100 is inserted up to innermost portion 120 of port 114, elastic member 106 comes into contact with the inner circumferential surface of innermost portion 120 and elastically compresses and deforms, generating an elastic force that presses sleeve 102 toward the center of innermost portion 120 of port 114, thereby pressing the tip end of piping 100 toward the center of innermost portion 120 of port 114.

[0020] An end of a flow channel 116 to which the piping 100 is to be fluidly connected faces the center of an innermost surface 118 of the port 114. The fluid connection of the piping 100 to the flow channel 116 is achieved by tightening the nut 110 onto the port 114 and pressing the sealing member 108 on the tip surface of the piping 100 and the sleeve 102 against the innermost surface of the port 114. At this time, the elastic force of the elastic member 106 aligns the tip of the piping 100 with the center of the innermost part 120 of the port 114, so that the central axis of the tip of the piping 100 and the central axis of the end surface of the flow channel 116 facing the innermost surface 118 of the port 114 approximately coincide, and the internal flow channel of the piping 100 is accurately fluidly connected to the flow channel 116.

[0021] A second embodiment of the pipe connection structure will be described with reference to FIG.

[0022] The second embodiment has a structure in which a pipe 200 is connected to a port 210 provided in a flow path block 208 .

[0023] The piping 200 is passed through the inside of a nut 206, and a sleeve 202 is attached to the tip of the piping 200. The position of the sleeve 202 is adjusted so that the tip surface is flush with the tip surface of the piping 200. The inner diameter of the nut 206 is smaller than the outer diameter of the sleeve 202. A ring-shaped seal member 204 made of an elastic material is attached to the tip surfaces of the piping 200 and the sleeve 202. The outer diameter of the sleeve 202 is slightly smaller than the inner diameter of the innermost part of the port 210. The sleeve 202 is made of resin or metal.

[0024] The elastic modulus of the seal member 204 may be smaller than the elastic modulus of the tip surface of the piping 200, the tip surface of the sleeve 202, and the innermost surface 214 of the port 210. For example, the tip surface of the piping 200, the tip surface of the sleeve 202, and the innermost surface 214 of the port 210 may be made of metal or ceramic, and the seal member 204 may be made of resin.

[0025] A groove 217 is provided in the circumferential direction on the inner peripheral surface of the deepest part 216 of the port 210, and a substantially cylindrical elastic member 218 is fitted into the groove 217. The inner diameter of the elastic member 218 is slightly smaller than the outer diameter of the sleeve 202 attached to the tip of the piping 200. The elastic member 218 is made of an elastic resin such as PEEK.

[0026] Elastic member 218 constitutes a pressing structure that presses the tip end of piping 200 toward the center of innermost portion 216 of port 210 when the tip end of piping 200, to which sleeve 202 is attached, is inserted up to innermost portion 216 of port 210. That is, when the tip end of piping 200 is inserted up to innermost portion 216 of port 210, elastic member 218 comes into contact with the outer peripheral surface of sleeve 202 and elastically compresses and deforms, generating an elastic force that presses sleeve 202 toward the center of innermost portion 216 of port 210, thereby pressing the tip end of piping 200 toward the center of innermost portion 216 of port 210. An inner edge 220 of elastic member 218 on the opening side of port 210 (right side in the figure) is tapered, so that sleeve 202 is smoothly guided inside elastic member 218 when the tip end of piping 200 is inserted toward innermost surface 216 of port 210.

[0027] An end of a flow channel 212, to which the piping 200 is to be fluidly connected, faces the center of an innermost surface 214 of the port 210. The fluid connection of the piping 200 to the flow channel 212 is achieved by tightening a nut 206 onto the port 210 and pressing a seal member 204 on the tip surface of the piping 200 and the sleeve 202 against the innermost surface 214 of the port 210. At this time, the elastic force of an elastic member 218 aligns the tip of the piping 200 with the center of the innermost part 216 of the port 210, so that the central axis of the tip of the piping 200 and the central axis of the end surface of the flow channel 212 facing the innermost surface 214 of the port 210 approximately coincide with each other, and the internal flow channel of the piping 200 is accurately fluidly connected to the flow channel 212.

[0028] A third embodiment of the pipe connection structure will be described with reference to FIGS.

[0029] This third embodiment is the same as the second embodiment in that a pressing structure is provided at the innermost part of the port 210, but the pressing structure is realized by a movable wall surface 224 and an elastic body 226 instead of the elastic member 216 of the second embodiment.

[0030] A cylindrical cavity 222 is provided in the innermost portion of port 210 of flow path block 208, and four movable wall surfaces 224 are arranged inside cavity 222. Elastic bodies 226 are interposed between the inner circumferential surface of cavity 222 and each of movable wall surfaces 224. The four movable wall surfaces 224 form the inner wall surfaces of the innermost portion of port 210. Each of elastic bodies 226 is a coil spring or the like that elastically deforms in the radial direction of cavity 222. The elastic deformation of elastic body 226 allows movable wall surfaces 224 to move in the radial direction of cavity 222, thereby elastically changing the inner diameter of the innermost portion of port 210.

[0031] The inner diameter of the innermost portion of port 210 is designed to be slightly smaller than the outer diameter of sleeve 202 attached to the tip of piping 200 when elastic body 226 is in its natural state and not elastically deformed. An inner edge 228 of movable wall surface 224 on the opening side of port 210 (the right side in the figure) is tapered, and when the tip of piping 200 is inserted toward the innermost surface of port 210, sleeve 202 comes into contact with tapered edge 228 of movable wall surface 224, pressing movable wall surface 224 radially outward, and the inner circumferential surface of movable wall surface 224 is forced to expand in accordance with the outer circumferential surface of sleeve 202. As movable wall surface 224 is forced to expand radially outward, elastic body 226 is elastically compressed, generating an elastic force in the radially inward direction. The elastic force of the elastic body 226 presses the sleeve 202 radially inward uniformly, thereby aligning the tip of the tubing 200 with the center of the innermost part of the port 210 .

[0032] In the third embodiment, the innermost wall surface of port 210 is formed by four movable wall surfaces 224, but the present invention is not limited to this, and it is sufficient if the inner diameter of the innermost portion is configured to include one or more movable wall surfaces and to be able to elastically change.

[0033] A fourth embodiment of the pipe connection structure will be described with reference to FIGS.

[0034] This fourth embodiment is similar to the second and third embodiments in that a pressing structure is provided at the innermost portion of port 236. In this fourth embodiment, three blocks 230, 232, and 234 are stacked together to form port 236 and flow path 244 to which piping 200 is to be connected. The pressing structure at the innermost portion of port 236 is formed by block 232 sandwiched between blocks 230 and 234.

[0035] The block 232 has four movable wall surfaces 238 formed in the center thereof, which form the inner wall surfaces of the innermost portion of the port 236. A cavity 240 is formed around the outer periphery of the movable wall surfaces 238 of the block 232, so that when a force is applied to the movable wall surfaces 238 from the inside, the movable wall surfaces 238 are elastically moved radially outward. The inner diameter of the circular openings formed inside the four movable wall surfaces 238 is slightly smaller than the outer diameter of the sleeve 202 attached to the tip of the piping 200. The inner edge 242 of the movable wall surfaces 238 on the opening side of the port 236 (the right side in the figure) is tapered. When the tip of the piping 200 is inserted toward the innermost surface of the port 210, the sleeve 202 comes into contact with the tapered edge 242 of the movable wall surfaces 238, which presses the movable wall surfaces 238 radially outward, causing the inner circumferential surfaces of the movable wall surfaces 238 to expand in accordance with the outer circumferential surface of the sleeve 202. When the movable wall surface 238 is pushed radially outward, an elastic force acts on the movable wall surface 238 in the radially inward direction, uniformly pressing the sleeve 202 in the radially inward direction, thereby aligning the tip of the piping 200 with the center of the innermost part of the port 236.

[0036] Although the first to fourth embodiments described above are structures for fluidly connecting a pipe to a flow path provided in a flow path block, the present invention is not limited to this and can be similarly applied to a pipe connection structure in which two pipes are butted together to fluidly connect them.

[0037] An embodiment of a pipe connection structure in which two pipes are fluidly connected by butting them together will be described with reference to FIGS. 7 and 8. FIG.

[0038] The embodiment of FIG. 7 is a modification of the first embodiment (see FIG. 1).

[0039] 7, ports 114-1 and 114-2 are provided on two opposite faces of block 112', and innermost portions 120' of ports 114-1 and 114-2 are connected so that the tip faces of two pipes 100 are butted together within innermost portion 120'. The inner diameter of innermost portion 120' is larger than the outer diameter of sleeve 102 attached to the tip end of pipe 100 and smaller than the outer diameter of elastic member 106 attached to the outer periphery of sleeve 102.

[0040] When the tip ends of the pipes 100 are inserted through the ports 114-1 and 114-2 and reach the innermost portion 120', the elastic force of the elastic members 106 attached to the outer periphery of the sleeve 102 aligns the tip ends of the pipes 100 with the center of the innermost portion 120'. As a result, the centers of the tip ends of the pipes 100 that are inserted through the ports 114-1 and 114-2 and butted together are aligned. The seal between the two butted pipes 100 is maintained by the seal members 108 attached to the tip faces of one or both of the pipes 100 being sandwiched between the tip faces of the other pipes.

[0041] The embodiment of FIG. 8 is a modification of the second embodiment (see FIG. 2).

[0042] 7, ports 210-1 and 210-2 are provided on two opposite faces of block 208', and innermost portions 216' of ports 210-1 and 210-2 are connected so that the tip faces of two pipes 200 are butted together within innermost portion 216'. A hollow cylindrical elastic member 218' is provided within innermost portion 216'. The inner diameter of innermost portion 216' is larger than the outer diameter of sleeve 202 attached to the tip end of pipe 200, and the inner diameter of elastic member 218' is slightly smaller than the outer diameter of sleeve 202.

[0043] When the tip ends of the pipes 200 are inserted through the ports 210-1 and 210-2 and reach the innermost portion 216', the elastic force of the elastic members 218' provided within the innermost portion 216' causes the tip ends of the pipes 200 to be aligned with the center of the innermost portion 216'. As a result, the centers of the tip ends of the pipes 200 that are inserted through the ports 210-1 and 210-2 and butted together are aligned approximately. The seal between the two butted pipes 200 is maintained by the seal members 204 provided on the tip end surfaces of one or both of the pipes 200 being sandwiched between the tip end surfaces of the two pipes 200.

[0044] Although Figures 7 and 8 show modified examples of the first and second embodiments, the pressing structures of the third and fourth embodiments can also be applied to a pipe connection structure in which two pipes are butted together.

[0045] Next, a fifth embodiment of the pipe connection structure will be described with reference to FIG.

[0046] The piping connection structure of this embodiment is a structure in which a piping 300 is connected to a port 316 provided in a flow path block 312 .

[0047] Pipe 300 is passed through the inside of second nut 308, and sleeve 302 is attached to the tip of pipe 300. The inner diameter of the second nut is slightly larger than the outer diameter of pipe 300 and smaller than the outer diameter of sleeve 302. The position of sleeve 302 is adjusted so that the tip surface is aligned with the tip surface of pipe 300. Annular seal member 310 made of an elastic material is attached to the tip surfaces of pipe 300 and sleeve 302.

[0048] Furthermore, the tip of pipe 300 is passed through alignment ferrule 304 and the inside of first nut 306. The inner diameter of alignment ferrule 304 is slightly larger than the outer diameter of sleeve 302 so that sleeve 302 can be inserted inside alignment ferrule 304. The inner diameter of first nut 306 is slightly larger than the outer diameter of sleeve 302. A cylindrical recess 306a is provided on the back surface of first nut 306 (the surface on the right side in the figure), and threads that mesh with the threads of second nut 308 are provided on its inner circumferential surface.

[0049] The outer peripheral surface of alignment ferrule 304 is tapered so that the outer diameter decreases toward the tip of piping 300. The inner peripheral surface of innermost portion 320 of port 316 is tapered at an angle corresponding to the outer peripheral surface of alignment ferrule 304.

[0050] When fixing the piping 300 to the port 316, by tightening the first nut 306 to the port 316, the tip of the piping 300 is aligned with the center of the innermost surface 320 of the port 316 due to the relationship between the outer circumferential surface of the alignment ferrule 304 and the inner circumferential surface of the innermost surface 320 of the port 316. Thereafter, by tightening the second nut 308 to the first nut 306 fixed to the port 316, the back surface of the sleeve 302 is pushed toward the back of the port 316 by the second nut 308, and the seal member 310 on the tip surfaces of the piping 300 and the sleeve 302 is pressed against the innermost surface of the port 316. This allows the piping 300 to be fluidly connected to the flow path 314 with the central axis of the tip of the piping 300 approximately aligned with the central axis of the flow path 314.

[0051] Next, a sixth embodiment of the pipe connection structure will be described with reference to FIG.

[0052] In this embodiment, a pipe 400 is passed through the inside of a nut 404, and a sleeve 402 is attached to the tip of the pipe 400. The inner diameter of the nut 404 is smaller than the outer diameter of the sleeve 402. The position of the sleeve 402 is adjusted so that the tip surface is aligned with the tip surface of the pipe 400. A circular recess 412 is provided in the innermost surface of the port 408 of the flow path block 406, and a ring-shaped seal member 414 made of an elastic material is fitted into and held in this recess 412. The seal member 414 may have an elastic modulus smaller than that of the pipe 400 and the tip surfaces of the sleeve 402.

[0053] That is, in this embodiment, seal member 414, which maintains liquid-tightness at the connection between pipe 400 and flow path 410, is held on the innermost surface of port 408 rather than on the tip surface of pipe 400. As a result, seal member 414 is held within port 408 even when pipe 400 is removed from port 408, and therefore the possibility of damage to seal member 414 can be reduced compared to when seal member 414 is held on the tip surface of pipe 400.

[0054] The elastic modulus of the seal member 414 may be smaller than the elastic modulus of the tip surface of the tubing 400, the tip surface of the sleeve 402, and the bottom surface of the recess 412 of the port 408. For example, the tip surface of the tubing 400, the tip surface of the sleeve 402, and the bottom surface of the recess 412 of the port 408 may be made of metal or ceramic, and the seal member 412 may be made of resin.

[0055] The above-described embodiments are merely examples of the pipe connection structure according to the present invention. The following are embodiments of the pipe connection structure according to the present invention.

[0056] In a first embodiment of the piping connection structure according to the present invention, A pipe connection structure in which a tip end of a pipe is inserted into a port to a predetermined position, thereby fluidly connecting the pipe to the port, a pressing structure that comes into contact with an outer peripheral surface of the tip end portion of the pipe that has been inserted to the predetermined position in the port and generates a pressing force on the outer peripheral surface of the tip end portion of the pipe toward the center of the port, The pressure structure is configured to generate a pressing force when the tip of the piping is inserted to the predetermined position in the port, so that the center of the tip of the piping and the center of the port are approximately aligned.

[0057] In aspect [1] of the first embodiment, the pressing structure includes an elastic member provided at the tip of the pipe, having an outer diameter larger than the inner diameter of the port, and elastically deforming in the radial direction of the pipe to conform to the inner surface of the port when the tip of the pipe is inserted into the port.

[0058] In the above aspect [1], a groove may be provided in the circumferential direction on the outer peripheral surface of the tip of the pipe, and the elastic member may be attached to the tip of the pipe by being fitted into the groove.

[0059] In the above case, an example of the material of the elastic member is resin.

[0060] In aspect [2] of the first embodiment, the pressing structure includes an elastic member that is provided at the predetermined position within the port, has an inner diameter smaller than the outer diameter of the piping, and comes into contact with the outer peripheral surface of the piping inserted up to the predetermined position in the port, thereby elastically deforming in the radial direction of the port to follow the outer peripheral surface of the piping.

[0061] In the above aspect [2], the end face of the elastic member located on the opening side of the port may have a tapered shape that is inclined so that the inner diameter becomes smaller as it goes toward the depth of the port.

[0062] In addition, in the above aspect [2], a groove may be provided in the circumferential direction on the inner surface of the port at the predetermined position, and the elastic member may be attached to the predetermined position of the port by being fitted into the groove.

[0063] In the above aspect [2], an example of the material of the elastic member is resin.

[0064] In aspect [3] of the first embodiment, the pressing structure forms an inner wall at the predetermined position of the port having an inner diameter smaller than the outer diameter of the piping, and includes a movable wall surface that elastically changes the inner diameter in accordance with the outer peripheral surface of the piping inserted up to the predetermined position.

[0065] In aspect [4] of the above embodiment, the tip surface of the piping is flat, and has a ring-shaped sealing member made of an elastic material that contacts the tip surface of the piping when the tip of the piping is inserted to the predetermined position in the port.

[0066] In aspect [5] of the above embodiment, the pressing structure includes an alignment ferrule provided at the predetermined position of the port, which has an inclined surface that slopes so that the inner diameter decreases with increasing distance from the opening of the port, and an alignment ferrule provided at the tip of the piping, which has an outer peripheral surface that slopes to correspond to the inclined surface at the predetermined position of the port, and the tip of the piping is inserted into the innermost side of the port, and the outer peripheral surface of the alignment ferrule of the piping slides along the inclined surface at the predetermined position of the port, thereby positioning the tip of the piping within the port and causing the center of the tip of the piping to approximately coincide with the center of the port.

[0067] In a second embodiment of the piping connection structure according to the present invention, A pipe connection structure in which a tip end of a pipe is inserted into a port to a predetermined position, thereby fluidly connecting the pipe to the port, The innermost surface of the port and the tip surface of the pipe are flat surfaces, a ring-shaped seal member made of an elastic material held on the innermost surface of the port; The sealing member is configured to be sandwiched between the innermost surface of the port and the tip surface of the piping when the tip of the piping is inserted to the predetermined position in the port, so that the internal flow paths of the piping and the port are fluidically connected in a liquid-tight manner.

[0068] In the aspect [1] of the second embodiment, a circular recess is provided in the innermost surface of the port, and the sealing member is fitted into the recess.

[0069] In the aspect [2] of the second embodiment, the elastic modulus of the sealing member is smaller than the elastic modulus of the innermost surface of the port and the tip surface of the pipe. [Explanation of symbols]

[0070] 100,200,300,400 piping 102,202,302,402 Sleeve 104,217 Groove 106,218,218' Elastic member 108,204,310,414 Sealing materials 110,206,306,308,404 Nut 114,210,236,316,408 ports 224,238 Movable walls 320 Alignment Ferrule

Claims

1. A pipe connection structure in which a tip end of a pipe is inserted into a port to a predetermined position, thereby fluidly connecting the pipe to the port, a pressing structure that comes into contact with an outer peripheral surface of the tip end portion of the pipe that has been inserted to the predetermined position in the port and generates a pressing force on the outer peripheral surface of the tip end portion of the pipe toward the center of the port, A piping connection structure configured to approximately align the center of the tip of the piping with the center of the port by the pressing force generated by the pressing structure when the tip of the piping is inserted to the predetermined position in the port.

2. 2. The pipe connection structure according to claim 1, wherein the pressing structure includes an elastic member provided at the tip portion of the pipe, having an outer diameter larger than an inner diameter of the port, and elastically deforming in the radial direction of the pipe to conform to the inner surface of the port when the tip portion of the pipe is inserted into the port.

3. 3. The pipe connection structure according to claim 2, wherein a groove is provided in the outer peripheral surface of the tip of the pipe in the circumferential direction, and the elastic member is attached to the tip of the pipe by being fitted into the groove.

4. The pipe connection structure according to claim 3 , wherein the elastic member is made of a resin.

5. 2. The piping connection structure according to claim 1, wherein the pressing structure includes an elastic member provided at the predetermined position within the port, having an inner diameter smaller than an outer diameter of the piping, and elastically deforming in the radial direction of the port to follow the outer peripheral surface of the piping by contacting the outer peripheral surface of the piping inserted up to the predetermined position in the port.

6. 6. The piping connection structure according to claim 5, wherein an end face of the elastic member located on the opening side of the port has a tapered shape inclined so that an inner diameter thereof decreases toward the depth of the port.

7. 6. The piping connection structure according to claim 5, wherein a groove is provided in the inner surface of the port at the predetermined position in the circumferential direction, and the elastic member is attached to the predetermined position of the port by being fitted into the groove.

8. The pipe connection structure according to claim 5 , wherein the elastic member is made of a resin.

9. 2. The piping connection structure according to claim 1, wherein the pressing structure forms an inner wall at the predetermined position of the port having an inner diameter smaller than an outer diameter of the piping, and includes a movable wall surface that elastically changes the inner diameter in accordance with the outer peripheral surface of the piping inserted up to the predetermined position.

10. The tip surface of the pipe is flat, 2. The pipe connection structure according to claim 1, further comprising a ring-shaped seal member made of an elastic material that contacts the tip surface of the pipe when the tip of the pipe is inserted to the predetermined position in the port.

11. 2. The piping connection structure according to claim 1, wherein the pressing structure includes an alignment ferrule provided at the predetermined position of the port, the alignment ferrule having an inclined surface that slopes so that the inner diameter decreases with increasing distance from the opening of the port, and an outer peripheral surface that slopes to correspond to the inclined surface at the predetermined position of the port, and the tip of the piping is inserted into the innermost side of the port and the outer peripheral surface of the alignment ferrule of the piping slides along the inclined surface at the predetermined position of the port, thereby positioning the tip of the piping within the port and causing the center of the tip of the piping to approximately coincide with the center of the port.

12. A pipe connection structure in which a tip end of a pipe is inserted into a port to a predetermined position, thereby fluidly connecting the pipe to the port, The innermost surface of the port and the tip surface of the pipe are flat surfaces, a ring-shaped seal member made of an elastic material held on the innermost surface of the port; a sealing member configured to be sandwiched between the innermost surface of the port and the tip surface of the piping when the tip of the piping is inserted to the predetermined position in the port, thereby fluidly connecting the internal flow paths of the piping and the port in a liquid-tight manner.

13. The pipe connection structure according to claim 12, wherein a circular recess is provided in the innermost surface of the port, and the seal member is fitted into the recess.

14. The pipe connection structure according to claim 12 , wherein the elastic modulus of the sealing member is smaller than the elastic modulus of the innermost surface of the port and the elastic modulus of the tip surface of the pipe.

15. 15. The pipe connection structure according to claim 14, wherein the innermost surface of the port and the tip surface of the pipe are made of metal or ceramic, and the seal member is made of resin.

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