JP4114572B2 - Manufacturing method of pipe joint structure - Google Patents

Description

The present invention manufactures a pipe joint structure in which a pipe having a large diameter portion as a joint portion is inserted into a through hole of a connector and the large diameter portion is press-fitted and fixed in a first recess provided at one end of the through hole. It is about the method .

  The present applicant has previously filed Japanese Patent Application No. 2002-192203 as a pipe joint structure suitable for a refrigerant pipe joint of a refrigeration cycle for vehicle air conditioning, for example.

  This pipe joint structure has a pipe having an annular projecting part (expanded diameter part) projecting outward in the radial direction and a through hole penetrating in the plate thickness direction, and has an inner diameter of the through hole on one end side of the through hole. And a connecting flange member (connector) having a large enlarged recess. Then, the pipe is held and fixed to the connector by inserting and fixing the enlarged diameter portion of the pipe into the enlarged concave portion of the connector while the pipe is inserted into the through hole of the connector.

  However, in the case of the above-described pipe joint structure, there is a gap between the pipe and the through hole, and the pipe is held and fixed to the connector at only one place of the press-fitting and fixing portion between the enlarged diameter portion and the enlarged recess. Therefore, the pipe shakes with the press-fit fixing part as a fulcrum due to vibration during movement between processes (until the connector is fixed to the expansion valve, for example), so the press-fit fixing part is loosened and the pipe comes out from the connector (the pipe joint structure is Not maintained).

In view of the above problems, and an object thereof is to provide a method for manufacturing a piping joint structure for preventing detachment of a pipe from the connector.

In order to achieve the above object, a method for manufacturing a pipe joint structure according to claim 1 includes a pipe having a diameter-enlarged portion as a joint portion, a through hole, and an inner diameter of the through hole at one end of the through hole. A manufacturing method of a pipe joint structure comprising a connector having a large first recess, wherein the expanded diameter portion is press-fitted and fixed to the first recess while the pipe is inserted into the through hole of the connector ,
Connector is configured to have a second recess to the other end of the through hole first recesses are formed over the upper and lower surfaces of the connector, the through-hole from the side surface, the first recess, and a pipe insertion opening reaching the second recess An insertion step of inserting the pipe into the through-hole through the pipe insertion opening of the connector so that the expanded diameter portion of the pipe is located on the first recess side;
A fixing member that is made of an elastically deformable material and that is provided in a substantially C shape in which the width of the opening tip is narrower than the outer diameter of the pipe, and that has a thin portion at the outer peripheral portion facing the opening tip, and a temporary stop step of temporarily fixed to the pipe extending from the concave side to the outside,
And a press-fitting step of press-fitting the fixing member into the second recess while simultaneously applying pressure to the enlarged diameter portion and the fixing member to press-fit the enlarged diameter portion into the first recess .

Thus, according to the manufacturing method of the pipe joint structure of the present invention, the expanded diameter portion of the pipe is press-fitted and fixed in the first recess provided at one end of the through hole, and the first provided at the other end of the through hole. The fixing member is press-fitted and fixed so as to fill the gap between the second recess and the pipe in the two recesses. That is, the pipe is held and fixed at two locations on the connector, and the pipe is less likely to shake due to vibration during movement between processes, so that the pipe can be prevented from coming off from the connector.

Further, both the first recess and the second recess use a simple mechanical assembly method called press-fitting. Moreover, since the connector need only be provided with the first recess and the second recess at both ends together with the through hole, it can be integrally formed by a method such as die casting. Therefore, the manufacturing cost can be suppressed.
In addition, since the fixing member is formed in a substantially C shape by an elastically deformable material, the contact area with the pipe is widened, and the pipe is stably held and fixed by the connector. Further, since the fixing member has a thin portion at the outer peripheral portion facing the opening tip, the fixing member is easily deformed so as to widen the opening tip, and the insertion property of the pipe to the fixing member can be improved. .
Furthermore, since the connector has a pipe insertion opening, even if the pipe has a larger diameter portion than the outer diameter of the pipe at both ends of the bent part and the pipe, Pipes can be inserted into the first recess and the second recess. Therefore, since a bending part can be formed in piping, the freedom degree of piping shape of a piping joint structure improves.
Moreover, since the press-fitting of the enlarged diameter portion and the fixing member is performed at the same time, the manufacturing process can be simplified.

The connector may be configured to hold only one pipe, or may be configured to hold a plurality of pipes as described in claim 2 .

When the connector holds a plurality of pipes as described in claim 2 , the fixing members may be press-fitted and fixed in the second recesses for the respective pipes, but the connector is provided in the connector as described in claim 3. The plurality of second recesses communicated with each other, and a common fixing member may be press-fitted and fixed to the plurality of second recesses. In this case, the number of parts of the fixing member can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic configuration diagram showing a pipe joint structure in the present embodiment, where (a) is a plan view seen from the fixing member side, and (b) is a cross-sectional view taken along the line AA of (a). . In addition, the piping joint structure in this Embodiment has illustrated what is used for the connection of the refrigerant | coolant piping of the refrigerating cycle for vehicle air conditioning.

  As shown in FIG. 1, the pipe joint structure 10 of the present embodiment includes two refrigerant pipes 20a and 20b, a connector 30 that holds and fixes the refrigerant pipes 20a and 20b, a refrigerant pipe 20a and 20b, and a connector 30. It is comprised by the fixing members 40a and 40b arrange | positioned between.

  The refrigerant pipes 20a and 20b are made of metal, and in this embodiment, both are formed using an aluminum alloy having relatively low hardness. Of the refrigerant pipes 20a and 20b, the large-diameter refrigerant pipe 20a is a low-pressure side refrigerant pipe of the refrigeration cycle, and the other small-diameter refrigerant pipe 20b is a high-pressure side refrigerant pipe of the refrigeration cycle. And the front-end | tip part of the refrigerant | coolant piping 20a is connected to the low voltage | pressure side refrigerant | coolant outlet part of the expansion valve (pressure reduction means) which is not shown in figure, and the refrigerant | coolant piping 20b is connected to the high voltage | pressure side refrigerant inlet part of an expansion valve.

  The refrigerant pipes 20a and 20b have the same shape with different diameters. The refrigerant pipes 20a and 20b both have annular enlarged portions 21a and 21b projecting radially outward near the end portions. The enlarged diameter portions 21a and 21b are larger than the first recess by a predetermined amount so as to be press-fitted and fixed in a first recess of the connector 30 described later, and are integrally formed in the pipe by a known processing method (for example, bulge processing). Yes.

  Further, the refrigerant pipes 20a and 20b have annular grooves 22a and 22b for accommodating an O-ring (not shown) on the tip side of the enlarged diameter parts 21a and 21b.

  The connector 30 is made of metal, and in the present embodiment, is formed using an aluminum alloy having higher hardness than the refrigerant pipes 20a and 20b. Further, as shown in FIGS. 1A and 1B and FIGS. 2A and 2B, the through holes 31a and 31b through which the refrigerant pipes 20a and 20b are inserted, and the through holes 31a and 31b, respectively. It has 1st recessed part 32a, 32b and 2nd recessed part 33a, 33b formed in the both ends.

  The through holes 31a and 31b penetrate in the thickness direction of the connector 30, and the refrigerant pipe 20a is inserted into the large diameter through hole 31a and the refrigerant pipe 20b is inserted into the small diameter through hole 31b. The refrigerant pipes 20a and 20b have an inner diameter that is larger than the outer diameter by a predetermined amount. The through holes 31a and 31b in the present embodiment have the same shape with different inner diameter dimensions. 2A and 2B are schematic views of the connector 30. FIG. 2A is a plan view seen from the second recesses 33a and 33b, and FIG. 2B is a cross-sectional view taken along the line BB in FIG.

  The first recesses 32a and 32b are provided at one ends of the through holes 31a and 31b, respectively. The enlarged diameter portion 21a is press-fitted and fixed to the first recess 32a, and the enlarged diameter portion 21b is press-fitted and fixed to the first recess 32b. The shape of the first recesses 32a and 32b is not particularly limited as long as the enlarged diameter portions 21a and 21b provided in the refrigerant pipes 20a and 20b can be press-fitted and fixed. With respect to 31b, a circular cross-sectional shape centering on the through holes 31a and 31b may be used, or a polygonal cross-sectional shape may be used. Further, the contact surface with the enlarged diameter portions 21a and 21b may be uneven. In the present embodiment, the two first recesses 32a and 32b have the same shape with different diameters, and the contact surfaces with the enlarged diameter portions 21a and 21b have an uneven shape (not shown). A predetermined amount smaller than the outer diameter of the diameter portions 21a and 21b is provided. The boundary between the first recesses 32a and 32b and the surface of the connector 30 is tapered so that the refrigerant pipes 20a and 20b can be easily press-fitted into the first recesses 32a and 32b.

  And the 2nd recessed part 33a, 33b is provided in the other end of the through-holes 31a, 31b. The shape of the second recesses 33a and 33b is not particularly limited as long as the fixing members 40a and 40b described later are press-fitted and fixed. For example, like the first recesses 32a and 32b, the through holes 31a and 31b are formed. The center may have a circular cross-sectional shape or a polygonal cross-sectional shape. Further, the contact surfaces with the fixing members 40a and 40b may be uneven. In the present embodiment, the two second recesses 33a and 33b have the same shape with different diameters, and have a circular cross-sectional shape centering on the through holes 31a and 31b, while being outside the fixing members 40a and 40b. A predetermined amount smaller than the diameter is provided. The boundary between the second recesses 33a and 33b and the surface of the connector 30 is tapered so that the fixing members 40a and 40b can be easily press-fitted into the second recesses 33a and 33b.

  As described above, the connector 30 has a structure including the first recesses 32a and 32b and the second recesses 33a and 33b at both ends of the two through holes 31a and 31b, and is made of an aluminum alloy. Is possible. Therefore, the processing cost can be suppressed.

  Further, the connector 30 of the present embodiment has refrigerant pipe insertion openings 34a and 34b reaching the through holes 31a and 31b, the first recesses 32a and 32b, and the second recesses 33a and 33b from the side surface over both the upper and lower surfaces. ing. Therefore, even if the refrigerant pipes 20a and 20b have bent portions and portions where the through holes 31a and 31b cannot be inserted (for example, enlarged diameter portions) at both ends, the refrigerant pipes 20a and 20b penetrate through the refrigerant pipe insertion openings 34a and 34b. The refrigerant pipes 20a and 20b can be inserted into the holes 31a and 31b, the first recesses 32a and 32b, and the second recesses 33a and 33b. That is, since the bent portions can be formed in the refrigerant pipes 20a and 20b (that is, the degree of freedom of the pipe shape of the refrigerant pipes 20a and 20b is improved), the pipe joint structure 10 according to the installation space can be obtained. .

  Between the two through holes 31a and 31b of the connector 30, two bolt through holes 35 penetrating in the same direction as the through direction of the through holes 31a and 31b are provided. The connector 30 is fastened and fixed to the housing portion of the expansion valve by a bolt (not shown) inserted into the bolt through hole 35.

  The fixing members 40a and 40b are made of a metal such as aluminum or a resin, and in the present embodiment, are formed using an elastically deformable resin. The fixing member 40a is press-fitted and fixed to the second recess 33a, and the fixing member 40b is press-fitted and fixed to the second recess 33b. The shapes of the fixing members 40a and 40b are not particularly limited as long as they can be press-fitted and fixed in the second recesses 33a and 33b, respectively. The fixing members 40a and 40b in the present embodiment are provided in the same substantially C shape although the sizes are different as shown in FIGS. 1 (a) and 1 (b) and FIGS. 3 (a) and 3 (b). In order to improve the insertion property of the refrigerant pipes 20a and 20b, the opening tip parts 41a and 41b for inserting the refrigerant pipes 20a and 20b, the holding parts 42a and 42b for holding and fixing the refrigerant pipes 20a and 20b, and the refrigerant pipes 20a and 20b. The thin-walled portions 43a and 43b. 3A and 3B are schematic views of the fixing member 40a (40b), where FIG. 3A is a plan view and FIG. 3B is a cross-sectional view taken along the line CC in FIG.

  The opening tip portions 41a and 41b have an opening width narrower than the outer diameter of the corresponding refrigerant pipes 20a and 20b. However, since the fixing members 40a and 40b are made of an elastically deformable resin and have thin portions 43a and 43b at outer peripheral portions facing the opening tip portions 41a and 41b, the widths of the opening tip portions 41a and 41b are large. The refrigerant pipes 20a and 20b can be inserted into the holding portions 42a and 42b. In addition, the holding portions 42a and 42b in the present embodiment have inner diameters that are substantially the same as or slightly smaller than the outer diameters of the corresponding refrigerant pipes 20a and 20b. Accordingly, since the refrigerant pipes 20a and 20b can be temporarily fixed before the press-fitting and fixing, the positioning at the press-fitting and fixing is easy. The holding portions 41a and 41b may not have an inner diameter substantially equal to or slightly smaller than the outer diameter of the refrigerant pipes 20a and 20b, and when the fixing members 40a and 40b are press-fitted and fixed to the second recesses 33a and 33b. In addition, the fixing members 40a and 40b may be elastically deformed to have an inner diameter capable of holding and fixing the refrigerant pipes 20a and 20b between the second recesses 33a and 33b.

  Thus, since the fixing members 40a and 40b of the present embodiment are provided in a substantially C shape having the thin portions 43a and 43b, the refrigerant pipes 20a and 20b have the holding portions 42a and 42b at the bent portions and both ends. Even if it has a portion (for example, a diameter-expanded portion) that cannot be inserted, the refrigerant pipes 20a and 20b can be inserted into the holding portions 42a and 42b. Moreover, even if it has the shape having the opening tip portions 41a and 41b, the contact area with the refrigerant pipes 20a and 20b can be ensured as wide as possible, so that the refrigerant pipes 20a and 20b can be stably held by the connector 30 during press-fitting. Can be fixed.

  In the pipe joint structure 10 including the above components, the refrigerant pipes 20a and 20b are inserted into the through holes 31a and 31b of the connector 30, respectively, and the enlarged diameter portions 21a and 21b of the refrigerant pipes 20a and 20b are first. While being press-fitted and fixed in the recesses 32a and 32b, the fixing members 40a and 40b are press-fitted and fixed in the second recesses 33a and 33b. Accordingly, since the refrigerant pipes 20a and 20b are held and fixed to the connector 30 at two locations in the longitudinal direction of the refrigerant pipes 20a and 20b, the refrigerant pipes 20a and 20b and the connector 30 are fixed between the expansion valves. It is possible to prevent vibration of the refrigerant pipes 20a and 20b due to vibration during movement. That is, it is possible to prevent the refrigerant pipes 20a and 20b from coming off from the connector 30 (a state where the pipe joint structure 10 is not maintained).

  Next, the manufacturing method (assembly method) of the pipe joint structure 10 in the present embodiment will be described with reference to FIGS. 4A and 4B are cross-sectional views for explaining the manufacturing method of the pipe joint structure 10, wherein FIG. 4A shows a state before press-fitting and FIG. 4B shows the end of press-fitting and fixing.

  First, refrigerant pipes 20a and 20b, connectors 30, and fixing members 40a and 40b, which are elements constituting the pipe joint structure 10, are prepared in advance. In the present embodiment, the second recesses 33a and 33b are integrally formed with the connector 30 together with the through holes 31a and 31b and the first recesses 32a and 32b by die casting.

  Then, the press-fitting process is performed using the press-fitting device 50. The press-fitting device 50 includes a fixed portion 51 and a pressurizing portion 52 that is disposed on the upper side of the fixed portion 51 and is movable in the vertical direction.

  As shown in FIG. 4 (a), the fixed portion 51 has positioning recesses 51a and 51b, and the end portions of the refrigerant pipes 20a and 20b are accommodated in the positioning recesses 51a and 51b with respect to the enlarged diameter portions 21a and 21b. In this state, the enlarged diameter portions 21 a and 21 b are brought into contact with the upper surface of the fixed portion 51, and the refrigerant pipes 20 a and 20 b are positioned and arranged on the fixed portion 51.

  Next, the connector 30 is positioned and arranged so that the refrigerant pipes 20a and 20b are fitted into the through holes 31a and 31b, and then the fixing members 40a and 40b are fitted so that the refrigerant pipes 20a and 20b are fitted into the holding portions 42a and 42b. Position and arrange.

  Then, as shown in FIG. 4B, pressure is applied in the direction of the arrow by the pressurizing unit 52 to push down the fixing members 40a and 40b and the connector 30 in the direction of the fixing unit 51. At this time, the enlarged diameter portions 21a and 21b of the refrigerant pipes 20a and 20b are press-fitted into the first recesses 32a and 32b and deformed in accordance with the shape of the first recesses 32a and 32 (side surfaces are uneven), thereby expanding. The outer peripheral surfaces of the diameter portions 21a and 21b are in close pressure contact with the inner walls of the first recesses 32a and 32b (first press-fitting step). That is, the refrigerant pipes 20 a and 20 b are held and fixed to the connector 30.

  The fixing members 40a and 40b are also press-fitted into the second recesses 33a and 33b of the connector 30 by the pressurizing force of the pressurizing part 52, and deformed following the shapes of the refrigerant pipes 20a and 20b and the second recesses 33a and 33b. The holding portions 42a and 42b of the fixing members 40a and 40b are in close pressure contact with the refrigerant pipes 20a and 20b, and the outer peripheral surfaces of the fixing members 40a and 40b are in close pressure contact with the inner walls of the second recesses 33a and 33b (see FIG. Second press-fitting step). That is, the refrigerant pipes 20a and 20b are held and fixed to the connector 30 via the fixing members 40a and 40b.

  Accordingly, the refrigerant pipes 20a and 20b are held and fixed to the connector 30 at two locations of the first concave portions 32a and 32b and the second concave portions 33a and 33b, which are the longitudinal directions of the pipes, so that the refrigerant pipes 20a and 20b are touched by vibration. Can be prevented, and the refrigerant pipes 20a and 20b from the connector 30 can be prevented from coming off. In addition, since the refrigerant pipes 20a and 20b can be stably fixed to the connector 30 by a simple mechanical assembly method such as press-fitting and fixing, brazing is unnecessary and the pipe joint structure 10 is manufactured at low cost. be able to.

  In the case of the present embodiment, the first press-fitting step and the second press-fitting step can be performed at the same time, so that the manufacturing process can be simplified. In addition, you may implement a 1st press injection process and a 2nd press injection process separately.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made.

  In this embodiment, the shape of the enlarged diameter parts 21a and 21b provided in the refrigerant pipes 20a and 20b is an annular shape. However, the shape of the enlarged diameter portions 21a and 21b is not limited to an annular shape, and may be any shape that can be press-fitted and fixed in the first recesses 32a and 32b.

  Moreover, in this embodiment, the example which hold | maintains and fixes two refrigerant | coolant piping 20a, 20b to one connector 30 was shown. However, the present invention can also be applied to a structure in which only one (refrigerant) pipe is fixed to one connector.

  Moreover, in this embodiment, the connector 30 showed the example which has the refrigerant | coolant piping insertion opening part 34a, 34b for fitting the refrigerant | coolant piping 20a, 20b to the through-holes 31a, 31b from the side surface side. However, as shown in FIG. 5, the connector 30 may not have the refrigerant pipe insertion openings 34a and 34b. However, in this case, the refrigerant pipes 20a and 20b need to be fitted into the through holes 31a and 31b through the through holes 31a and 31b, and the shapes of the refrigerant pipes 20a and 20b are restricted. FIG. 5 is a plan view showing a modified example of the connector 30.

  Moreover, in this embodiment, the fixing member 40a, 40b showed the example provided in the substantially C shape which has thin part 43a, 43b. However, the shape of the fixing members 40a and 40b is not limited to the above example, and is a shape that is press-fitted into the second recesses 33a and 33b and is in close pressure contact with the second recesses 33a and 33b and the refrigerant pipes 20a and 20b. If it is good. For example, when the fixing members 40a and 40b are made of an elastically deformable resin, as shown in FIG. 6A, the fixing members 40a and 40b may be substantially C-shaped without the thin portions 43a and 43b. Further, when the fixing members 40a and 40b are made of metal or resin, as shown in FIG. 6B, the fixing members 40a and 40b may be provided in an annular shape having through holes through which the refrigerant pipes 20a and 20b can be inserted. As shown in FIG. 6 (c), the width of the opening tip may be provided in a substantially U shape that is substantially the same as the outer diameter of the refrigerant pipes 20a and 20b. However, in the case of the annular shape shown in FIG. 6B, it is necessary to penetrate the refrigerant pipes 20a and 20b, so that the shapes of the refrigerant pipes 20a and 20b are restricted. 6 (a) and 6 (c), the refrigerant pipes 20a and 20b can be fitted from the side as in the present embodiment. However, in the case of FIG. In some cases, the fixing members 40a and 40b may be twisted, and in the case of FIG. 6C, the area where the refrigerant pipes 20a and 20b can be held is smaller than the substantially C shape. Therefore, it is preferable to provide a substantially C shape having the thin portions 43a and 43b shown in the present embodiment. 6A to 6C are plan views showing modifications of the fixing members 40a and 40b.

  Moreover, in this embodiment, the fixing members 40a and 40b showed the example comprised from one component. However, the fixing members 40a and 40b may be composed of a plurality of parts. For example, as shown to Fig.7 (a), you may be comprised from 2 components which become an annular | circular shape in the combined state. In addition, an example in which one fixing member 40a, 40b is arranged for one refrigerant pipe 20a, 20b is shown. However, the two second recesses 33a and 33b of the connector 30 communicate with each other, and as shown in FIG. 7B, a common fixing member 40a (40b) may be disposed on the refrigerant pipes 20a and 20b. In this case, since the two (plural) refrigerant pipes 20a and 20b can be held and fixed by one fixing member 40a and 40b, the number of parts can be reduced. 7A and 7B are plan views showing modifications of the fixing members 40a and 40b.

It is a schematic block diagram which shows the piping joint structure in the 1st Embodiment of this invention, (a) is the top view seen from the fixing member side, (b) is sectional drawing in the AA cross section of (a). . 2A and 2B are schematic views of the connector, in which FIG. 2A is a plan view seen from the second recess side, and FIG. 3A and 3B are schematic views of the fixing member, in which FIG. 3A is a plan view and FIG. 3B is a cross-sectional view taken along the line CC in FIG. It is sectional drawing according to process for demonstrating the manufacturing method of a pipe joint structure, (a) is before press-fit fixation, (b) is a figure which shows the time of press-fit fixation completion | finish. It is a top view which shows the modification of a connector. (A)-(c) is a top view which shows the modification of a fixing member. (A), (b) is a top view which shows the modification of a fixing member.

Explanation of symbols

10 ... Pipe joint structure 20a, 20b ... Refrigerant piping 21a, 21b ... Diameter expansion part 30 ... Connector 31a, 31b ... Through-hole 32a, 32b ... 1st recessed part 33a, 33b. ..Second recesses 40a, 40b ... fixing members

Claims (3)

A pipe having a diameter-enlarged portion as a joint portion; and a connector having a through-hole and having a first recess larger than the inner diameter of the through-hole at one end of the through-hole, the pipe being the through-hole of the connector A method of manufacturing a pipe joint structure in which the enlarged diameter portion is press-fitted and fixed to the first recess while being inserted into the first recess,
The connector is configured to have a second recess to the other end of the through-hole in which the first recess is formed over the upper and lower surfaces of the connector, the through-hole from a side surface, said first recess and said second recess An insertion step of inserting the pipe into the through-hole through the pipe insertion opening of the connector, so that the expanded diameter portion of the pipe is located on the first recess side,
A fixing member made of an elastically deformable material and provided in a substantially C shape in which the width of the opening tip is narrower than the outer diameter of the pipe, and has a thin portion at an outer peripheral portion facing the opening tip, A temporary fixing step of temporarily fixing to a pipe extending outside from the second concave portion side ;
And a press-fitting step of press-fitting the fixing member into the second recess while simultaneously applying pressure to the enlarged-diameter portion and the fixing member to press-fit the enlarged diameter portion into the first recess. A manufacturing method of a characteristic pipe joint structure. The method for manufacturing a pipe joint structure according to claim 1, wherein the connector is configured to hold a plurality of the pipes . The piping according to claim 2, wherein the plurality of second recesses provided in the connector communicate with each other, and the common fixing member is press-fitted and fixed to the plurality of second recesses. Manufacturing method of joint structure .

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