JP4199717B2 - Header piping connection structure - Google Patents

Description

The present invention relates to a header pipe connection structure.

  In piping equipment for supplying fluid, a piping unit is used that supplies fluid from a header having a plurality of branch pipe connection ports through a branch pipe to a water supply port, a hot water supply port, or the like. This piping unit is generally shipped after a branch pipe is connected to a header in advance at a factory or the like.

  FIG. 7 shows a cross-sectional view when a conventional branch pipe connecting portion and a branch pipe are welded. 7, the branch pipe 20 is fitted into the branch pipe connection port 12 of the header 10, and the branch pipe connection port 12 and the tip fitting portion 21 of the branch pipe 20 overlap each other. Welding was carried out over almost the entire length of the fitting allowance 41, and the periphery of the opening 13 of the branch pipe connection opening 12 was welded to increase the connection strength.

  However, when installing the piping unit at the work site, the entire piping unit or only the header and branch pipes are lifted up, so the weight of the branch pipe places a load on the connection between the header and the branch pipe, and the welded part The branch pipe breaks with the base point. In particular, when the temperature was lowered, the branch pipe was more likely to be damaged starting from the welded portion contracted by the heat welding region.

  In Patent Document 1, a rotational welding receptacle made of crosslinked polyethylene is provided at the rotational welding receptacle of the header body, a branch pipe made of crosslinked polyethylene is inserted through a cylindrical body made of crosslinked polyethylene, A method of rotating friction welding between the outer surface of a cylindrical body and the inner surface of the rotary welding receptacle and between the inner surface of the cylindrical body and the outer surface of the branch pipe is disclosed.

In this Patent Document 1, branch pipes are inserted into a header via a cylindrical body made of crosslinked polyethylene, and these members are rotated to cause friction welding. Therefore, since the connection part between the header and the branch pipe is firmly fixed, it is possible to prevent the connection part between the header and the branch pipe from being damaged by a load, low temperature, or the like.
JP 2003-176897 A

  However, in patent document 1, when connecting a branch pipe to a header, since the member of a cylindrical body is used, the number of parts increases and it becomes high cost. Moreover, in order to make it weld by rotational friction, it is necessary to process each member, and there exists a problem that production efficiency also worsens.

  Then, this invention aims at provision of the header piping connection structure which can prevent a damage of a connection part with few members and work processes.

In order to solve the above problems, the present invention is a header pipe connection structure in which a second pipe is fitted and connected to a connection port portion of a first pipe, and overlaps in the pipe direction of the first pipe and the second pipe. Of the fitting allowance, only the front end side of the second pipe and the back side of the connection opening of the first pipe are melted and welded.

  Here, the fitting allowance is a portion where the first pipe and the second pipe overlap when the second pipe is fitted and connected to the first pipe.

  Of this fitting allowance, the melted portions are the outer peripheral surface on the tip side of the second pipe and the inner peripheral surface on the back side of the connection port portion of the first pipe corresponding thereto. The connection strength between the first pipe and the second pipe is ensured in this heat welding region.

  Moreover, the part which does not fuse | melt, ie, a non-welding area | region, is an opening side inner peripheral surface of the connection port part of 1st piping, and the outer peripheral surface of 2nd piping corresponding to this in a fitting margin. By this non-welding region, the second piping can be moved with the heat welding region as a base point even when a load is applied from a direction orthogonal to the piping direction. Thereby, with respect to the load in the direction orthogonal to the piping direction of the second piping, the contact portion between the rim of the connection port of the first piping and the second piping bears a part of the load, and the load applied to the heat welding region Can be reduced. Therefore, it is possible to prevent the heat welding region from being damaged.

  A slight gap may be formed between the opening side inner peripheral surface of the connection port portion of the first pipe that is the non-welding region and the second pipe. In this case, at least the outer diameter of the second pipe is formed smaller than the inner diameter of the connection port portion of the first pipe. That is, a gap can be formed between the connection port portion of the first pipe and the second pipe in the non-welded region. By this gap, the second pipe can move with the heat welding region as a base point even when a load is applied from a direction orthogonal to the pipe direction. Thereby, with respect to the load in the direction orthogonal to the piping direction of the second piping, the contact portion between the rim of the connection port of the first piping and the second piping bears a part of the load, and the load applied to the heat welding region Can be reduced. Therefore, it is possible to prevent the heat welding region from being damaged.

  Such a connection method and connection structure can also be applied to the connection of the branch pipe to the header. For example, the first pipe is a header and the second pipe is a branch pipe.

  As described above, according to the present invention, since only a part of the fitting allowance between the first pipe and the second pipe is welded, the movable range of the second pipe is increased, and the second pipe with the heat welding area as a base point. Can be prevented from being damaged.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is an overall perspective view of a header according to the present invention, FIG. 2 is an exploded cross-sectional view of a branch pipe connection port portion and a tip fitting portion, and FIG. 3 is a cross-sectional view in which the branch pipe connection port portion and the tip fitting portion are welded. 4 is a cross-sectional view of a branch pipe connection port portion showing a reference example .

  As shown in FIG. 1, the piping unit connects a plurality of branch pipes branched from a main pipe through which a fluid such as water supply or hot water flows into a kitchen, a wash basin, a bathroom, a toilet, and the like. And a branch pipe 20 that is fitted and connected to the branch pipe connection port portion 12.

  As shown in FIGS. 2 and 3, the branch pipe 20 includes a tip fitting portion 21 that fits with the branch pipe connection port portion 12, and a pipe main body portion that is not fitted with the branch pipe connection port portion 12 and is exposed to the outside. 25. The branch pipe 20 is made of, for example, a thermoplastic resin, but is preferably made of the same material as the header 10.

  The header 10 includes a straight tubular header main body 11 and a plurality of branch pipe connection ports 12 protruding in a direction orthogonal to the pipe direction of the header main body 11. The header main body 11 and the branch pipe connection opening 12 are integrally formed of a thermoplastic resin such as polybuden or polyethylene.

The branch pipe connection ports 12 are arranged at equal intervals in the pipe direction of the header body 11. Each branch pipe connection port part 12 is provided with a fitting allowance 41 and a pipe stop part 14 from the opening 13 side toward the back.
The fitting allowance 41 is a portion where the distal end fitting portion 21 of the branch pipe 20 and the branch pipe connection port 12 overlap when the branch pipe 20 is fitted and connected to the branch pipe connection port 12. At this time, in the fitting allowance 41, portions where the inner peripheral surface on the back side of the branch pipe connection port 12 and the outer peripheral surface on the front end side of the front end fitting portion 21 are melted and welded are referred to as heat welding regions 15 and 22. The portions that are not welded are designated as non-welded regions 16 and 23.

  The heat welding region 15 is a region that is welded to the heat welding region 22 disposed on the outer peripheral surface on the front end side of the front end fitting portion 21. The inner diameter of the branch pipe connection opening 12 is formed to be equal to or slightly smaller than the outer diameter of the branch pipe 20. Thus, when the inner peripheral surface of the heat welding region 15 and the outer peripheral surface of the heat welding region 22 of the tip fitting portion 21 are melted, the inner diameter of the heat welding region 15 of the branch pipe connection port portion 12 and the tip fitting portion 21 The thickness overlapped with the outer shape of the heat welding region 22 is melted and can adhere to each other. The non-welding region 16 is a region that does not weld to the inner peripheral surface of the branch pipe connection port portion 12 other than the heat welding region 15, that is, the tip fitting portion 21 in the fitting allowance 41.

A reference example is shown in FIG . This is an example in which the outer diameter of the branch pipe 20 is made smaller than the inner diameter of the branch pipe connection port portion 12 and the gap 42 is formed in the non-welded regions 16 and 23 of the branch pipe connection port portion 12 and the tip fitting portion 21. is there. However, the outer diameter of the branch pipe 20 is a diameter that can be welded to the branch pipe connection port portion 12 by heat welding in the heat welding region 22.

  The tube stopper 14 is a stopper that prevents excessive fitting in the pipe direction when the branch pipe 20 is fitted into the branch pipe connection opening 12. In order to perform this function, the inner diameter of the tube stopper 14 is formed smaller than the outer diameter of the branch pipe 20. Thereby, the pipe stop part 14 can prevent the fluid which passes the inside of the header main body 11 from the clearance gap between the internal peripheral surface of the branch pipe connection port part 12, and the outer peripheral surface of the front-end | tip fitting part 21. Further, the inner diameter of the tube stopper 14 is formed to be at least larger than the inner diameter of the branch pipe 20 to be connected. Thereby, the pipe stop part 14 does not stop the flow of the liquid passing through the inside of the branch pipe 20.

  Further, a shape retaining sleeve 50 is fitted into the distal end fitting portion 21 of the branch pipe 20 so as not to be thermally deformed when melted by a heater or the like. The shape retaining sleeve 50 is provided with a tube main body 51 and a flange 52 at one end of the tube main body 51, and is formed slightly longer than the length of the distal end fitting portion 21 of the branch pipe 20. Since the outer diameter of the tube main body 51 of the shape retaining sleeve 50 is smaller than the inner diameter of the branch tube 20, it can be fitted into the tip fitting portion 21. The flange 52 is formed larger than the inner diameter of the branch pipe 20 and smaller than the outer shape of the branch pipe 20. Therefore, the flange 52 does not hinder the insertion of the branch pipe 20 into the branch pipe connection port portion 12.

  A plurality of convex protrusions 53 are arranged on the surface of the tube main body 51 on the flange 52 side of the shape retaining sleeve 50 so as to be arranged with a uniform width in the circumferential direction. The apex of the protrusion 53 is formed slightly larger than the inner diameter of the branch pipe 20. Therefore, when the shape retaining sleeve 50 is inserted into the distal end fitting portion 21, the protrusion 53 is forcibly fitted into the distal end fitting portion 21, and the shape retaining sleeve 50 is fixed. Thereby, it is possible to prevent the shape-retaining sleeve 50 from being detached during operations such as melting the heat welding region 22 of the branch pipe 20 and fitting it into the branch pipe connection opening 12.

The shape retaining sleeve 50 is formed of, for example, polyphenylene ether resin having a melting temperature higher than that of the branch pipe 20. Thereby, even if the heat melting part 22 of the tip fitting part 21 is melted, the shape is maintained by the shape retaining sleeve 50. In addition, although the polyphenylene ether resin is used for the material of the shape retention sleeve 50, it is not this limitation in particular. For example, any material that has a higher melting temperature than the material of the branch pipe 20, such as aluminum, stainless steel, or iron, may be used.
Next, the positions at which the non-welding region 16, the heat welding region 15, and the tube stopper 14 are formed in the branch pipe connection port 12 are determined by the sizes of the header 10 and the branch pipe 20, as shown in Table 1. Is done.

例えば、枝管２０のサイズが１３Ａ（管外径：１７ｍｍ）の場合、非溶着領域１６の位置は開口１３からヘッダ本体１１の方向に８ｍｍとされ、熱溶着領域１５の位置は非溶着領域１６の奥側からヘッダ本体１１の方向に７ｍｍとされる。すなわち、枝管接続口部１２と先端嵌合部２１との嵌め代４１の長さは接続口１２から１５ｍｍとされる。なお、非溶着領域１６の長さは、ヘッダ１０および枝管２０のサイズに関係なく、枝管接続口部１２の開口１３からヘッダ本体１１の方向に８ｍｍの長さに統一される。

For example, when the size of the branch pipe 20 is 13A (pipe outer diameter: 17 mm), the position of the non-welding area 16 is 8 mm from the opening 13 toward the header body 11, and the position of the heat welding area 15 is the non-welding area 16. 7 mm in the direction of the header body 11 from the back side. That is, the length of the fitting allowance 41 between the branch pipe connection port portion 12 and the tip fitting portion 21 is 15 mm from the connection port 12. The length of the non-welded region 16 is unified to a length of 8 mm from the opening 13 of the branch pipe connection port 12 to the header body 11 regardless of the sizes of the header 10 and the branch pipe 20.

  The position of the pipe stop portion 14 is formed at a position 18 mm from the opening 13 of the branch pipe connection port portion 12, that is, at a depth of 3 mm from the back side of the fitting allowance 41 to the header body 11 side. The width of 3 mm is such that when the heat welding regions 15 and 22 of the branch pipe connection port portion 12 and the tip fitting portion 21 are welded, the melted surfaces are rubbed against each other by inserting the branch pipe 20 in the back. It becomes a space to store the molten residue that is pushed away. Since there is a space for storing the melted residue, an assumed welding area between the inter-branch connecting portion 12 and the inter-branch 20 can be secured.

  The header 10 and the branch pipe 20 are connected by fitting the branch pipe 20 from the branch pipe connection port 12. At this time, the inner peripheral surface of the branch pipe connection port 12 and the outer peripheral surface of the branch pipe 20 are welded by previously melting and fitting a part of the fitting allowance 41 of the branch pipe connection port 12 and the branch pipe 20. Is done.

  For example, as shown in Table 1, when the branch pipe 20 has a size of 13A (pipe outer diameter: 17 mm), the length for melting and welding the branch pipe connection port portion 12 and the tip fitting portion 21 is a fitting allowance. 41 is set to 15 mm, and the length of the heat welding regions 15 and 22 is set to 7 mm. In addition, the non-welding area | region 16 of the branch pipe connection port part 12 is an inner peripheral surface of the range of 8 mm toward the back side from the opening 13, and the heat welding area | region 15 is an inner peripheral surface of the range of 7 mm further toward the back. is there. The heat welding region 22 of the tip fitting portion 21 is formed on the outer peripheral surface in the range of 7 mm from the opening 24.

  An assembly procedure of the header structure configured as described above will be described with reference to FIGS. 5A and 5B show the header melting heater, FIG. 5A is a front view of the header electric heater, and FIG. 5B is a cross-sectional view taken along the line A-A in FIG. FIG. 6 shows a branch pipe melting heater, FIG. 6A is a front view of the branch pipe electric heater, and FIG. 6B is a sectional view taken along line BB in FIG.

  First, the inner peripheral surface of the heat welding region 15 of the branch pipe connection port portion 12 and the outer peripheral surface of the heat welding region 22 of the tip fitting portion 21 are melted. At this time, melting of the heat welding regions 15 and 22 of the branch pipe connection port portion 12 and the tip fitting portion 21 is performed using electric heaters 31 and 32 as shown in FIGS. 5 and 6.

  In the case of the branch pipe connection port portion 12, as shown in FIG. 5, when an electric heater 31 is inserted into the branch pipe connection port portion 12 and inserted to the pipe stop portion 14, the inner peripheral surface in the vicinity is melted. At this time, the electric heater 31 is melted at the electric heating portion 33 on the distal end side of the portion fitted into the branch pipe connection port portion 12.

  In the case of the tip fitting portion 21, as shown in FIG. 6, the tip fitting portion 21 is inserted into the electric heater 32, and when the tip is inserted to the back of the electric heater 32, the outer peripheral surface in the vicinity is melted. At this time, the electric heater 32 is melted by the electric heating portion 34 located at the back side of the portion fitted to the tip fitting portion 21, that is, the position facing the opening 24 side of the branch pipe fitting portion 21.

  The melted tip fitting portion 21 is fitted from the opening 13 of the branch pipe connection port portion 12. At this time, it fits in until it hits the pipe stop part 14 formed in the branch pipe connection port part 12. Thereby, the heat-melting area | region 15 of the branch pipe connection port part 12 and the heat-melting area | region 22 of the front-end | tip fitting part 21 can be welded.

  The welding between the branch pipe connection port 12 and the tip fitting portion 21 is on the opening 24 side of the tip fitting portion 21 and on the back side of the branch pipe connection port portion 12. Further, the outer peripheral surface other than the opening 13 side of the branch pipe connection port portion 12 and the heat welding region 22 of the tip fitting portion 21 is not melted. Thereby, the non-welding area | regions 16 and 23 which are not welded are formed in the outer peripheral surface other than the heat welding area | region 22 of the opening 13 side of the branch pipe connection port part 12 and the front-end | tip fitting part 21. FIG.

The non-welding regions 16 and 23 can freely move the branch pipe 20 with the heat welding regions 15 and 22 as a base point. Therefore, with respect to a load in a direction orthogonal to the piping direction of the branch pipe 20, the contact portion between the lip of the opening 13 of the branch pipe connection port portion 12 and the branch pipe 20 receives a load, and bending stress is generated at this portion. In the bending direction of the branch pipe, a contracting force in the piping direction is generated on the inner side, and an extending force in the piping direction is generated on the outer side in the bending direction. However, the bending stress is absorbed by the non-welded areas branch pipe 20 itself expands and contracts, so that to reduce the load on the welding zone 15, 22, welding zone 15, 22 are prevented from being damaged be able to.

[Example]
Next, Table 2 shows the effect test results of the pipe connection method of the present invention. In the effect test, the branch pipe 20 is fitted and connected to the branch pipe connection port 12 of the header 10, and the branch pipe 20 is fixed to the pipe main body 25 having a length of 125 mm from the heat welding region 22 in the vertical direction with the header 10 fixed. It was lifted at a speed of 50 mm per minute, and the maximum load and the displacement at the time of buckling or breaking were measured.

  The measurement sample has three sizes of 10A (pipe outer diameter: 13 mm), 13A (pipe outer diameter: 17 mm), and 16A (pipe outer diameter: 22 mm), and the conventional example shown in FIG. The product according to the present invention (Example 1) having no gap between the mouth 12 and the product was compared, and the room temperature was measured at room temperature (23 ° C.).

  The effect test was performed three times for each size, and the average value was listed in the table. In addition, the “break at the time of thermal welding” described in the remarks column indicates that the boundary between the heat welding region 22 and the non-welding region 23 of the tip fitting portion 21 is broken. And “No fracture: 2/5” means that the heat-welded region 23 is equally divided into five in the pipe direction, and 1/5, 2/5, 3/5, 4 in order from the opening side of the tip fitting portion 21. / 5, 5/5, where the branch pipe 20 is broken.

この試験結果によると、室内温度が常温の場合は、従来例も実施例１もさほど差異はない。

According to this test result, when the room temperature is room temperature, there is not much difference between the conventional example and Example 1.

Next, Table 3 shows the welding strength test results at a low temperature (0 ° C.). A sample in which a gap 41 is formed between the inner peripheral surface of the branch pipe connection port portion 12 and the outer peripheral surface of the tip fitting portion 21 in the measurement sample at normal temperature (23 ° C.) (conventional example, Example 1). Experiments were performed by adding ( Reference Example 2, Reference Example 3 ).

In Reference Example 2, the inner diameter of the branch pipe connection port 12 is 18 mm (gap 42 is 0.5 mm), and in Reference Example 3, the inner diameter of the branch pipe connection port 12 is 17.6 mm (gap 42 is 0.3 mm). did. In addition, the effect test was performed three times for each sample, and the average value was described.

表３に示すように、いずれの実施例および参考例においても、従来例よりも溶着強度が大幅に増加した。さらに、実施例１にいたっては、枝管２０が座屈するまで熱溶着領域１５，２２が破断することはなかった。

As shown in Table 3, in any of the examples and reference examples , the welding strength was significantly increased as compared with the conventional example. Furthermore, in Example 1 , the heat-welded regions 15 and 22 were not broken until the branch pipe 20 was buckled.

In the maximum load, Example 1 shows the highest value, and then, in order of Reference Example 3 and Reference Example 2 . Moreover, in the case of the reference example 3 , the displacement has the highest value, and then, in the order of the example 1 and the reference example 2 . This is because the gap 41 is formed in the non-welding regions 16 and 23, thereby widening the range in which the branch pipe 20 can operate in the load direction.

  As described above, in the first embodiment, the branch pipe 20 can be moved by the non-fused areas 16 and 23, so that the branch pipe itself can be expanded and contracted, and the load on the heat welding areas 15 and 22 can be reduced. it can. That is, although the effect varies depending on the size of the header 10 and the branch pipe 20, the embodiment of the present invention is more effective in both breaking load and displacement than the conventional example, and the effect is particularly great at low temperatures.

  In addition, this invention is not limited to the said embodiment, A correction and a change can be added within the scope of the present invention.

  In addition, the shape of the branch pipe connection part is formed in a straight tube shape when viewed from the side cross section. For example, the connection port to the insertion part is tapered from the side cross section, and the back side from the heat welding region is formed. May be stepped. Further, the entire branch pipe connection portion, that is, the space from the connection port to the pipe body may be tapered. In addition, the inner end portion of the connection port of the branch pipe connection portion is not particularly processed in the present embodiment, but may be formed into a shape that allows easy insertion of the branch pipe or a shape that does not damage the branch pipe. For example, a chamfering process or a process of rounding the end face shape may be performed. Accordingly, the branch pipe can be smoothly fitted into the branch pipe connecting portion. Further, it is possible to prevent the branch pipe from being bent and coming into contact with the end portion due to handling at the time of installation, the weight of the branch pipe, or the like, and damaging the branch pipe itself.

  In this embodiment, the shape of the header and the branch pipe is a cylinder. However, this is not particularly limited, and a polygonal shape such as a square or a hexagon, or a circular shape such as an ellipse or an oval may be used.

Overall perspective view of header according to the present invention Exploded sectional view of branch pipe connection port and tip fitting Sectional view in which the branch pipe connection port and the tip fitting part are welded Sectional view of branch pipe connection port showing a reference example (A) is a front view of the electric heater for headers, (b) is an AA cross-sectional view of (a). (A) is a front view of an electric heater for branch pipes, (b) is a BB sectional view of (a). Sectional view when a conventional branch pipe connection and a branch pipe are welded

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Header 11 Header main body 12 Branch pipe connection port part 13 Opening 14 Pipe stop part 15 Thermal welding area | region 16 Non-welding area | region 20 Branch pipe 21 Tip fitting part 22 Thermal welding area | region 23 Specific heat melting area | region 24 Opening 25 Pipe main body part 31 Branch pipe Electric heater for connecting part 32 Electric heater for branch pipe 33 Electric heating part 34 Electric heating part 41 Fitting allowance 42 Gap 50 Shape-retaining sleeve 51 Pipe body 52 Flange 53 Projection

Claims (3)

A header pipe structure in which a branch pipe made of a thermoplastic resin is fitted and connected to a branch pipe connection port of a header made of a thermoplastic resin,
The inner diameter of the branch pipe connection port and the outer diameter of the end fitting portion of the branch pipe are set to the same dimension,
The fitting allowance that overlaps in the pipe direction between the branch pipe connection port and the tip fitting part of the branch pipe includes a heat welding region on the back side of the branch pipe connection port and the tip side of the branch pipe, and the branch pipe A header pipe connection structure comprising: a non-welded region on the opening side of the connection port portion. A shape retaining sleeve is fitted into the branch pipe so that the distal end side of the branch pipe is not thermally deformed by heat fusion,
The header pipe connection structure according to claim 1, wherein the shape retaining sleeve is formed longer than a length of a distal end fitting portion of the branch pipe. 3. The header pipe connection structure according to claim 2 , wherein the shape retaining sleeve is formed of a resin having a melting temperature higher than that of the branch pipe.

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