JP6685203B2 - Fitting - Google Patents

Description

  The present invention relates to a synthetic resin connecting pipe (joint).

  For example, Patent Document 1 proposes a connection pipe joint in which pipes made of thermoplastic synthetic resin are welded to each other so as to prevent the generation of inner beads. In Patent Document 1, the tubular ends of a pair of resin molded products to be joined are heated by a heating means until they are melted, and the tubular ends are pressed against each other to be melt-bonded, and the bonded state is kept under pressure for a certain period of time. It is described that the inner surface bead generated on the inner surface of the pipe is reduced to a smooth state by stretching in the direction opposite to the pressing direction.

JP 2004-216859 A

However, in the welding method described in Patent Document 1, the tubular ends of the resin molded product are heated by the heating means until they are melted, and the tubular ends are pressed and pressure-welded to each other to perform the melt-bonding. In order to maintain the pressure, the molten resin squeezes out in the pipe inner circumferential direction and rises as a molten bead, and the joint welding cross-section area decreases due to deformation due to the discrepancy at the joints between the pipe joints. There is a problem that voids (air bubbles) are easily generated.
Further, when the molten resin between the synthetic resin pipes is squeezed out to smoothly reduce the bulged joint as a molten bead, in the stretching step, temperature control of the heat source heater and peripheral members, etc. There are many conditions to be controlled such as pressure holding method, cooling method, etc., it is difficult to cope with creating a temperature environment, and it is difficult to maintain appropriate strength because the welding cross-section area and the melted part thickness decrease. I also have the problem.

  Therefore, such a connecting pipe joint is required to be an inexpensive synthetic resin pipe member, a welding method with few conditions to be controlled, and further easy to assemble.

  An object of the present invention is to provide a thermo-welded thermoplastic synthetic resin joint which can obtain a desired welding strength and does not leak from a welded portion.

The above-mentioned object is a flange formed on the end side of the body and having a diameter larger than that of the body, a male-side connecting tube portion formed at the end of the flange and having a diameter smaller than the flange, and the male side. A thermoplastic synthetic resin male-side fluid coupling having a root portion radial recess formed in the root side of the flange of the connection tubular portion and formed so as to have an outer diameter smaller than that of the male-side connection tubular portion, A female side fluid coupling made of thermoplastic synthetic resin having a flange formed at an end of the body portion and having a diameter larger than that of the body portion, and a female side pipe connecting portion having an inner diameter larger than the outer diameter of the male side connecting cylinder portion. The flange of the male side fluid coupling and the flange of the female side fluid coupling are heat welded to each other in a state where the male side connection tubular portion is fitted to the female side pipe connecting portion, and the root portion radial direction concave portion You enter a part of the resin of the flange of the female fluid coupling to It is achieved by the joint.

  According to the present invention, it is possible to provide a thermo-welded thermoplastic synthetic resin joint which can obtain a desired welding strength and does not leak from a welded portion.

The perspective view which shows the L-type male side fluid coupling which is one Example of this invention. The perspective view which shows the T type female side fluid coupling which is one Example of this invention. The front view which shows the joint formed by welding the L-type male side fluid coupling and the T-type female side fluid coupling which are 1st Example of this invention. The front view of the L-type male side fluid coupling and the T-type female side fluid coupling before welding. The figure which combined the L type male side fluid coupling and the T type female side fluid coupling in the state which has not been welded. FIG. 6 is a sectional view taken along the line AA shown in FIG. 5. Sectional drawing before combining an L-type male side fluid coupling and a T-type female side fluid coupling. Sectional drawing of the L-type male side fluid coupling and the T-type female side fluid coupling after welding. The figure which shows a heat welding apparatus.

  Embodiments will be described below with reference to the drawings.

  For example, in a heat pump type hot water supply apparatus using a refrigeration cycle, high temperature water stored in a hot water storage container is used as a heat medium to heat tap water serving as a heat exchange medium, and hot water generated by heating the tap water is used. Hot water to people. Such a heat pump type hot water supply device circulates a hot water supply heat exchanger or a hot water storage container that heats tap water by exchanging heat between tap water and hot water, so that the pipe flow path has many bends and branches. These flow paths are configured by a plurality of connecting pipe joints (hereinafter, also referred to as fluid joints and connecting pipes).

  FIG. 3 shows a fluid coupling 3 having both a bent portion and a branched portion by combining a fluid joint having a bent portion and a fluid joint having a branched portion. A fluid coupling having this curved portion is shown in FIG. The fluid coupling having the bent portion shown in FIG. 1 is an L-shaped male side fluid coupling (male side connecting pipe) 1. The L-shaped male side fluid coupling 1 is formed of a thermoplastic synthetic resin. Specifically, it is made of PPS (polyphenylene sulfide) and has a melting point of 290 degrees.

  The L-shaped male side fluid coupling 1 has a tubular fastener receiving portion 13 having an outer diameter slightly larger than the outer diameter of the male side body portion 14 at one end of the male side body portion 14 having a bent portion and a straight portion. Are formed. A cylindrical male side flange 12 is formed adjacent to the end of the fastener receiving portion 13. The outer diameter of the male side flange 12 is larger than the outer diameter of the fastener receiving portion 13, and the width in the axial direction is formed thinner than the fastener receiving portion 13. Further, on the side opposite to the fastener receiving portion 13 of the male side flange 12, a male side connecting cylinder portion 10 having the same outer diameter as the male side body portion 14 is formed. A root-portion radial recess 11 that is a groove having a diameter smaller than the outer diameter of the male-side connection tubular portion 10 is circumferentially formed at the root of the male-side flange 12 of the male-side connection tubular portion 10. Reference numeral 15 is a flange joint surface, which will be described in detail later.

  The fastener receiving portion 13 is a portion for connecting the connection pipes with each other by a fastener (not shown). However, since the fastener receiving portion 13 is not used in the present embodiment, it is not particularly necessary.

  Further, the end portion on the opposite side of the L-shaped male side fluid coupling 1 may be formed with the male side flange 12, the male side connecting cylinder portion 10 and the root portion radial direction recessed portion 11 described above, but another method. It may be a shape for connecting by.

FIG. 2 shows a T-shaped female side fluid coupling (female side connection pipe) 2 which is a coupling having a branch portion. Like the L-shaped male side fluid coupling 1, this T-type female side fluid coupling 2 is formed of PPS which is a thermoplastic synthetic resin.
Although the L-shaped male side fluid coupling 1 and the T-type female side fluid coupling 2 are made of PPS in the above embodiment, the present invention is not limited to this, and ABS (acrylonitrile butadiene styrene) melting point 100 to 125 degrees, PC (polycarbonate) melting point 150 degrees, POM (polyoxymethylene) melting point 181 degrees, PMMA (polymethylmethacrylate) melting point 90 to 105 degrees, PP (polypyrene) melting point 168 degrees, or PBT (polybutylene terephthalate) melting point 232 to 267 degrees. May be used.

  The T-shaped female side fluid coupling 2 has connecting portions for connecting to other joints formed at both ends of a linear female side body portion 24, and is connected to a branch portion and its end on the outer circumference of the female side body portion 24. Parts are formed.

  A tubular fastener receiving portion 23 having a large outer diameter of the female body portion 24 is formed on one end side of the female side body portion 24, and the outer diameter of the end portion of the fastener receiving portion 23 is larger than that of the fastener receiving portion 23. A larger female flange 22 is formed. The female side flange 22 has a cylindrical shape, and its width in the axial direction is narrower than the width of the fastener receiving portion 23. On the inner wall surfaces of the fastener receiving portion 23 and the female side flange 22, the female side in-pipe connecting portion 21 having an inner diameter larger than the inner diameter of the female side body portion 24 and slightly larger than the outer diameter of the male side connecting tubular portion 10. Are formed. In addition, although 25 is a flange joint surface, details are mentioned later.

  Similar to the L-shaped male side fluid coupling 1, the fastener receiving portion 23 may or may not be provided. The structure of the other end may be the structure described above or a different structure. An example of the different structure will be briefly described with reference to FIG.

  An O-ring (not shown) is fitted into the O-ring insertion groove 26 formed in the cylindrical connecting portion provided at the tip of the male connecting pipe flange on one end side of the T-type female side fluid coupling 2 shown in FIG. The cylindrical connecting portion is inserted into the female-side in-pipe connecting portion of the other joint of the connection destination that is not connected, and is held by a quick fastener member (not shown) over the entire circumference of the flange.

  However, since it is attached with a detachable sliding structure, there is a slight gap, so that minute dust is caught in the connection sealing surface and the influence of the molding surface roughness of the connection sealing surface causes water leakage. This is a structure that may cause problems. In addition, complicated mixing pipes and branch pipes are joined by combining TIG welding and brazing with stainless steel pipes, copper pipes, etc. as connecting pipe joints, which is troublesome to assemble in addition to the material unit price. There was also a problem that the manufacturing unit price would be high.

  Next, as shown in FIG. 4, the flange joint surface 15 of the L-shaped male side fluid coupling 1 and the flange joint surface 25 of the T-shaped female side fluid coupling 2 are made to face each other, and the male side connection tubular portion 10 is connected to the female side. By fitting in the pipe connecting part 21, the fluid coupling 3 shown in FIG. 3 is obtained. At this time, both flange joint surfaces 15 and 25 are inserted so as to make surface contact. In this state, the two are not touched, so they are easily separated.

  FIG. 5 is a diagram in which the fluid coupling 3 shown in FIG. 1 is rotated 90 degrees clockwise around the pipe axis of the T-shaped female side fluid coupling 2. FIG. 6 is a view showing the AA cross section. The fluid coupling 3 shown in FIG. 1 shows a state in which the L-shaped male side fluid coupling 1 and the T-type female side fluid coupling 2 are bonded, but FIG. 5 is an unbonded state.

  Referring to the cross-sectional view of FIG. 6, it can be seen that the joint surfaces of the male side flange 12 and the female side flange 22 having substantially the same diameter as that of the male side flange 12 are in surface contact with each other. Then, it can be seen that the root radial recess 11 of the L-shaped male side fluid coupling 1 exists as a space inside the female side flange 22 in the radial direction. Further, since the axial length of the male-side connecting tubular portion 10 including the root-portion radial recessed portion 11 is formed to be slightly shorter than the axial length of the female-side in-pipe connecting portion 21, the axial gap 30 appears. I understand that.

  Next, a method of adhering the L-shaped male side fluid coupling 1 and the T-shaped female side fluid coupling 2 will be described.

  In FIG. 7, after heat is applied to the flange joint surface 15 of the male side flange 12 of the L-shaped male side fluid coupling 1 and the flange joint surface 25 of the female side flange 22 of the T type female side fluid coupling 2 to melt them, The L-shaped male side fluid coupling 1 and the T-type female side fluid coupling 2 are fitted so that the flange joint surfaces 15 and 25 are in close contact with each other, and the L-shaped male side fluid coupling 1 is further pressured to the flange joint surfaces 15 and 25. And the T-shaped female side fluid couplings 2 are pressed against each other (one may be stationary and the other may be pressed against one).

  FIG. 8 shows a cross-sectional view in which the L-shaped male side fluid coupling 1 and the T-shaped female side fluid coupling 2 are heat-welded through such a process. As a result of pressurizing and holding in the pressing direction for a certain period of time, the molten resin protruding in the inner circumferential direction of the pipe flows into the root radial recess 11 described in FIG. 6, and the root radial recess 11 is filled to form the elution fitting portion 32. It The resin that has flowed into the root radial recess 11 is considered to be mainly the resin on the inner surface of the female side flange 22.

  Further, the flange joint surfaces 15 and 25 are adhered to each other to form a welded surface 31.

  The effects of the elution fitting portion 32 and the welding surface 31 will be described. The elution fitting portion 32 is formed by the resin of the T-shaped female side fluid coupling 2 flowing into the root radial recess 11 of the L-shaped male side fluid coupling 1, so that the elution fitting portion 32 will be cooled and solidified. , T-shaped female side fluid coupling 2 is a claw-shaped member formed over the entire circumference of the inner surface of the female side flange 22. The claw-shaped elution fitting portion 32 formed over the entire circumference of the inner surface bites into the root radial recess 11 of the L-shaped male side fluid coupling 1, so that the L-shaped male side fluid coupling 1 and the T-type female side The tensile strength, which is the strength in the direction in which the fluid coupling 2 is pulled, increases.

  On the other hand, in the welding surface 31, since the surfaces of the flange joint surfaces 15 and 25 are adhered to each other by welding, for example, when the joint 3 is used for a pipe of a water heater, water or hot water flows as a fluid inside the pipe, Even if a leak is made beyond the elution fitting portion 32, the welding surface 31 is surface-bonded to prevent leakage of the internal fluid. The same applies when the fluid is gas.

  Furthermore, since no bead is generated on the inner surface of the pipe of the joining portion shown in the prior art, in other words, since the conventional bead is used as the elution fitting portion 32, when used as the pipe of the water heater, the pipe Liquid pools and bubbles generated by the beads inside are suppressed.

  Next, a thermal welding apparatus that realizes this welding will be described with reference to FIG. The left side of the drawing is the L-shaped male side fluid coupling 1, and the right side is the T-type female side fluid coupling 2. These are fixed to work clamps 54 and 53 which are movable in the left-right direction on the paper. Further, the heating plate 50 is for melting the flange joint surfaces 15 and 25 of both, and is provided with an escape hole 55 for escaping the male side connecting cylinder portion 10 of the L-shaped male side fluid coupling 1 and is provided inside. The heaters 51 and 52 are provided. The heaters 51 and 52 have an amount of heat that causes the flange joint surfaces 15 and 25 to be melted in a predetermined time by releasing heat from the heating plate 50.

  Grasp both joints at positions where the work clamps 53 and 54 are separated from each other, move the heating plate 50 that has been heated to a predetermined temperature to the position shown in FIG. 9, and move the work clamps 53 and 54 to the position shown in FIG. To start heating. The heating is performed without contact with the heating plate 50. When heated for a predetermined time, the flange joint surfaces 15 and 25 are melted, and molten resin portions 120 and 220 are formed as shown in the figure. Next, the work clamps 53 and 54 are separated from each other, the heating plate 50 is retracted, and the work clamps 53 and 54 are brought close to each other until the molten resin portions 120 and 220 come into contact with each other. Further, the work clamps 53 and 54 are pressed with a predetermined pressing amount in the pressing direction for a predetermined time. By this pressurization, as described above, the welding surface 31 and the elution fitting portion 32 are formed. After that, the L-shaped male-side fluid coupling 1 and the T-type female-side fluid coupling 2 that have become the joint 3 from the work clamps 53 and 54 are removed to complete the process.

  The molten resin melted by pressurizing the molten resin portions 120 and 220 flows into the root radial recess 11 to form the elution fitting portion 32. The relationship between the molten resin and the size of the groove depends on the breaking strength. It was confirmed by an experiment that it is related to (pressure at the time of closing the fluid coupling and breaking by applying water pressure).

  The breaking strength is determined by the amount of the resin from the molten resin parts 120 and 220 flowing into the root radial recess 11. It is considered that the fracture strength is obtained not by the width of the groove in the tube radial direction of the root radial recess 11 but by the molten resin entering the groove bottom in the groove depth direction. Originally, it may be calculated by the volume of the root radial recess 11 (groove), but the wall area of this groove (the volume of the groove is calculated by multiplying this by the length of the groove in the tube axis direction). As a representative, the relationship between the ratio of the resin portion to the cross-sectional area and the fracture strength when the male-side connecting cylinder portion 10 was cut in the radial direction was calculated by an experiment.

  According to an experiment, the ratio of the cross-sectional area of the groove wall to the cross-sectional area of the resin portion when the male-side connecting cylinder portion 10 is cut in the radial direction is in the range of 15% to 50%, preferably 15% to 45%. It has been found that it is possible to satisfactorily obtain a fracture strength having a sufficient margin against the water pressure used in the water heater.

  This is because the root radial recess 11 (groove) is too deep, that is, if the ratio is more than 50%, it is difficult for the molten resin to reach the deepest part of the groove and a void-like space is generated. On the contrary, if the groove is too shallow, the amount of resin in the elution fitting portion 32 will decrease.

  In the embodiment described above, the L-shaped male side fluid coupling 1 is configured by providing the L-shaped fluid coupling with the male side joint portion (male side flange 12, root portion radial recess 11, male side connection tubular portion 10). Then, the T-type female side fluid coupling 2 was configured by providing the female side joint (female side flange 22, female side in-pipe connecting portion 21) in the T-type fluid coupling. The present embodiment can be applied to any fluid coupling without needing to be particular about it.

  Although the root radial recess 11 is provided so as to contact the flange joint surface 15, it may be provided at a distance from the flange joint surface 15. In this case, the flow of the molten resin melted from the inner surface of the female side flange 22 becomes a little worse. Furthermore, although the root radial recess 11 is provided over the entire circumference of the male-side connecting tubular portion 10, it does not have to be the entire circumference, and there are several portions having the same diameter as the male-side connecting tubular portion 10 in the circumferential direction. It may be.

  It should be noted that the present invention is not limited to the above-described embodiments, but includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described.

  DESCRIPTION OF SYMBOLS 1 ... L type male side fluid coupling (male side connecting pipe), 2 ... T type female side fluid coupling (female side connecting pipe), 3 ... Joint, 10 ... Male side connecting cylinder part, 11 ... Root part radial concave part, 12 ... Male-side flange, 15 ... Flange joint surface, 21 ... Female-side pipe connecting portion, 22 ... Female-side flange, 25 ... Flange joint surface, 31 ... Welding surface, 32 ... Elution fitting portion

Claims (1)

A flange formed on the end side of the body part and having a diameter larger than this body part, a male side connection cylinder part formed on the end part of this flange and smaller in diameter than this flange, and a male side connection cylinder part of this male side connection cylinder part. A male side fluid coupling made of a thermoplastic synthetic resin, which has a root-portion radial recess formed on the root side of the flange and having an outer diameter smaller than that of the male-side connecting cylinder portion, and an end of the body section. A female fluid coupling made of thermoplastic synthetic resin, which has a flange formed in a portion having a diameter larger than that of the body portion, and a female side pipe connecting portion having an inner diameter larger than the outer diameter of the male side connecting cylinder portion; In a state where the male-side connecting cylinder portion is fitted to the in-pipe connecting portion, the flange of the male-side fluid coupling and the flange of the female-side fluid coupling are heat-welded to each other, and the female-side flange portion is provided with the female-side coupling portion. A joint in which a part of the resin of the flange of the fluid joint has entered.

Images