JP2005201571A - Resin pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin pipe capable of preventing wrinkling and cracking of a weld part even in a case when an object having a projecting part on an outer periphery of a tip end part is forcibly drawn. <P>SOLUTION: In this resin pipe having a pipe part 111 projecting from a main body part 110 and a projecting part 112 projecting along the outer periphery of a tip end side of the pipe part 111, a thick part 114 for thickening the projecting part 112 is formed at an inner peripheral face 13 side near the weld part formed on the projecting part 112 in injecting a resin material. Whereby the strength of the projecting part 112 near the weld part can be increased, and the wrinkling and cracking of the projecting part 112 in forcibly drawing the resin pipe, can be prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a resin pipe, and is suitable for application to, for example, a resin tank of a vehicle radiator.

  As a conventional resin pipe, for example, as shown in Patent Document 1, there is a pipe applied to a resin tank of a vehicle radiator. Protruding portions (protruding portions in Patent Document 1) that are protruding along the outer periphery are provided.

And when molding this resin pipe, in order to improve the sealing performance with the hose, so-called forced punching molding so that the parting line of the mold does not remain on the outer surface of the part where the hose is inserted May do.
Japanese Patent Laid-Open No. 2003-232600

  However, forced punching is to pull out the mold in the longitudinal direction of the pipe while deforming the tip of the pipe (while bending the protruding part toward the inner diameter side). There was a problem that wrinkles and cracks were likely to occur in the welds formed according to the direction.

  In view of the above problems, an object of the present invention is to provide a resin pipe capable of preventing the occurrence of wrinkles and cracks in a weld portion even when forcibly punching and forming a projecting portion on the outer periphery of the tip portion. is there.

  In order to achieve the above object, the present invention employs the following technical means.

  In the first aspect of the present invention, the pipe portion (111) projecting from the main body portion (110) and the projecting portion (112) projecting along the outer periphery on the front end side of the pipe portion (111) are provided. In the resin pipe, on the inner peripheral surface (113) side in the vicinity of the weld portion generated in the projecting portion (112) when the resin material is injected, a thick portion (114) for increasing the thickness of the projecting portion (112) is provided. It is characterized by being provided.

  As a result, the strength of the projecting portion (112) in the vicinity of the weld portion can be increased, so that it is possible to prevent wrinkles and cracks generated in the projecting portion (112) when forcibly punching and molding the resin pipe. it can.

  The invention according to claim 2 is characterized in that the boundary portion (115) between the thick wall portion (114) and the inner peripheral surface (113) is smoothly connected.

  Thereby, the stress concentration to the boundary part (115) at the time of forced punching can be suppressed.

  In the third aspect of the invention, an annular thinned portion (116) is formed on the inner peripheral surface (113) side in the vicinity of the protruding portion (112), and the thick portion (114) is removed. It is provided to fill the meat part (116).

  As a result, the thick part (114) does not protrude from the inner peripheral surface (113), and there is no undercut of the molding die arranged on the inner peripheral surface (113) side of the pipe part (111). Can be made easier.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment description mentioned later.

(First embodiment)
A first embodiment of the present invention is shown in FIGS. In the first embodiment, the resin pipe of the present invention is applied to the tanks 110 and 120 of the automotive radiator 100. 1 is an external perspective view showing the entirety of the radiator 100 for an automobile, FIG. 2 is a front view showing the position of a weld portion generated in the pipe portions 111 and 121 when the tanks 110 and 120 are molded, and FIG. FIG. 4 is a perspective view from the direction A in FIG. 3, FIG. 5 is a cross-sectional view taken along the line BB in FIG. 4, FIG. 6 is a cross-sectional view showing a mold when the tank 110 is formed, and FIG. These are sectional drawings which show the movement of a metal mold | die when forcibly punching and forming the pipe part 111. FIG.

  As shown in FIG. 1, an automotive radiator (hereinafter referred to as a radiator) 100 is a so-called vertical flow type in which the coolant flowing in the tube 132 of the core portion 130 is directed downward from above in the figure. As a core part 130, an upper tank 110, and a lower tank 120.

  The core part 130 is comprised from the fin 131, the tube 132, the side plate 133, and the core plate 134, and these members are formed from the aluminum alloy excellent in strength resistance and corrosion resistance. The fins 131 formed in a corrugated shape from thin strips and the tubes 132 having a flat cross section are alternately arranged in the left-right direction. A plate 133 is provided. Ends in the vertical direction of each tube 132 are fitted into tube holes provided in the core plate 134, and these are integrally brazed.

  The upper tank 110 and the lower tank 120 (corresponding to the main body of the present invention) are formed from a resin material having excellent heat resistance and strength resistance, such as nylon material containing glass fiber, and the cross-sectional shape is substantially U-shaped. (See FIG. 6), and a container body having an opening on the side facing the core plate 134 is formed. A sealing member (packing) (not shown) is interposed between the outer peripheral portion of the opening of both tanks 110 and 120 and the outer peripheral portion of the core plate 134, so that both tanks 110 and 120 are mechanically connected to the core portion 130. Are joined (assembled by caulking).

  The upper tank 110 is integrally formed with a pipe portion (inlet pipe) 111 protruding so as to intersect the longitudinal direction, a water injection port 117 for injecting cooling water, and a mounting portion 118 for mounting to the vehicle as the radiator 100. The lower tank 120 is integrally formed with a pipe portion (exit pipe) 121 and a mounting portion 122. An engine hose (not shown) is inserted into each of the pipe portions 111 and 121, and cooling water from the vehicle engine flows into the upper tank 110 and the core portion 130 from the pipe portion 111, and heat with external air in the core portion 130. Cooled by replacement. Thereafter, the cooling water flows out from the pipe portion 121 of the lower tank 120 and returns to the engine again.

  In addition, as shown in FIG. 2, both tanks 110 and 120 are configured such that one end side in the longitudinal direction is a gate and a resin material is injected therefrom to be molded. , 121, a weld portion is formed on the side opposite to the gate. The weld portion is a portion where the flow of the resin material divided into two in the pipe portions 111 and 121 is joined and welded as indicated by the broken line arrow in FIG. Inferior.

  In the present invention, the structures of the pipe portions 111 and 121 of both tanks 110 and 120 are characterized, and the details thereof will be described below. Since the pipe portions 111 and 121 have the same structure on both the upper tank 110 and the lower tank 120 side, the following description will be made using the pipe portion 111 on the upper tank 110 side.

  As shown in FIGS. 3 to 5, the pipe portion 111 has a cylindrical shape, and is provided with a protruding portion 112 that has a protruding shape along the outer periphery on the distal end side. The protrusion 112 is intended to prevent the protrusion after the vehicle-side hose is inserted. Further, as will be described later, in order to improve the formability when the pipe portion 111 is forcibly punched and formed, an annular thinning portion 116 is provided on the inner peripheral surface 113 side in the vicinity of the protruding portion 112. .

  And the thick part 114 which thickens the thickness of the protrusion part 112 is provided in the inner peripheral surface 113 side corresponding to the weld part vicinity produced in the protrusion part 112 of the pipe part 111. As shown in FIG. The thick portion 114 is formed like a wall extending in the vertical direction in contact with the inner peripheral surface 113 in FIG. 4 (in a crescent-shaped cross section), and partially fills the thinned portion 116 described above. It is supposed to be. Further, the boundary portion 115 between the thick portion 114 and the thinned portion 116 (inner peripheral surface) is smoothly connected by an R shape.

  As shown in FIGS. 6 and 7, the pipe portion 111 is formed by forcible punching. That is, with respect to the upper tank 110 formed by the fixed mold 210 and the movable mold 220 movable in the vertical direction in FIG. 6 with respect to the fixed mold 210, the pipe portion 111 has an outer side movable in the horizontal direction in FIG. The insert mold 230 and the middle pin 240 are formed.

  After the pipe portion 111 (upper tank 110) is formed (FIG. 7A), the outer insert mold 230 and the intermediate pin 240 are released by first removing the intermediate pin 240 (FIG. 7B). The insert mold 230 is pulled out together with the pins 240 (FIGS. 7C and 7D). At this time, the outer nested mold 230 is originally undercut with respect to the projecting portion 112, but can be released by deforming (bending) the projecting portion 112 to the inner diameter side.

  As described above, when the pipe portion 111 is forcibly punched and formed, the weld portion of the protruding portion 112 that is deformed in the prior art may have wrinkles and cracks due to poor strength characteristics. By providing the thick portion 114 partially, the strength of the protruding portion 112 in the vicinity of the weld portion can be increased, so that when the pipe portion 111 is forcibly punched and formed, the wrinkles generated in the protruding portion 112 Cracking can be prevented.

  At this time, since the boundary portion 115 between the thick wall portion 114 and the thinned portion 116 (inner peripheral surface) is connected smoothly, stress concentration on the boundary portion 115 during forced punching is suppressed. can do.

  Further, since the thick portion 114 is provided so as to fill the thinned portion 116, the thick portion 114 does not protrude from the inner peripheral surface 113 and is disposed on the inner peripheral surface 113 side of the pipe portion 111. The undercut of the middle pin 240 can be eliminated to facilitate molding.

(Other embodiments)
In the first embodiment, the thick portion 114 has been described as having a crescent-shaped cross section. However, the present invention is not limited to this, and the thickness may be constant along the thinned portion 116. And the thickness should just be set according to the intensity | strength of the protruding part 112 required.

  If the thick wall portion 114 extends beyond the inner peripheral surface 116 to the inner diameter side, the middle pin 240 is pulled out to the side opposite to the pipe portion, although the molding cost is increased. The opening for 240 extraction may be closed by welding or the like with a closing member. And if this is used, this invention is applicable also to the case where the pipe part 111 does not provide the thinning part 116. FIG.

  In the first embodiment, the tanks 110 and 120 of the radiator 100 have been described by taking the pipe portions 111 and 121 as examples. However, the present invention is not limited to this, and other heat exchangers (intercoolers, heater cores, etc.) ) Tanks, reserve tanks, engine hose connection conduits and the like.

It is an external appearance perspective view which shows the whole radiator for motor vehicles. It is a front view which shows the position of the weld part which generate | occur | produces in a pipe part at the time of tank shaping | molding. It is an external appearance perspective view which shows a pipe part. It is an arrow view from the A direction in FIG. It is sectional drawing of the BB part in FIG. It is sectional drawing which shows the metal mold | die at the time of tank shaping | molding. It is sectional drawing which shows a motion of the metal mold | die when forcibly punching and forming a pipe part.

Explanation of symbols

101 Upper tank (main part)
111 Pipe part 112 Projection part 113 Inner peripheral surface 114 Thick part 115 Boundary part 116 Dehumidification part

Claims (3)

A pipe portion (111) protruding from the main body portion (110);
In the resin pipe having a projecting portion (112) that forms a projecting shape along the outer periphery on the front end side of the pipe portion (111),
On the inner peripheral surface (113) side in the vicinity of the weld portion generated in the projecting portion (112) when the resin material is injected, a thick portion (114) for increasing the thickness of the projecting portion (112) is provided. Plastic pipe characterized by that.   The resin pipe according to claim 1, wherein a boundary portion (115) between the thick portion (114) and the inner peripheral surface (113) is smoothly connected. An annular thinned portion (116) is formed on the inner peripheral surface (113) side in the vicinity of the protruding portion (112),
The resin-made pipe according to claim 1 or 2, wherein the thick part (114) is provided so as to fill the thinned part (116).

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