Composite molded body and pressure vessel integrated with composite molded body

Abstract

To ensure the sealing of a joint between a metal insert member and a resin molded body.SOLUTION: A composite molded body 10 is formed by integrating a metal insert member 11 having a cylindrical outer surface and a resin molded body 12 formed from thermoplastic resin. The insert member 11 and the resin molded body 12 are integrated by insert injection molding. The resin injected during insert injection molding covers at least a portion of the outer peripheral surface of the insert member 11, specifically an annular region CF, so as to adhere closely to the resin. The annular region CF is provided with a conical tapered surface 14 and an annular groove 15, with the annular groove 15 positioned on the larger diameter side of the tapered surface 14.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a composite molded body in which a metal member and a resin member are integrated by insert injection molding, and also to a pressurizing container in which the composite molded body is integrated. [Background technology]

[0002] Cooling systems used in automobiles and other vehicles are sometimes equipped with circulation systems that circulate a refrigerant. In these systems, the refrigerant is sometimes circulated under pressure. In such cases, a pressurizing container is sometimes installed in the refrigerant circulation path to absorb volume changes such as expansion and contraction due to heat of the refrigerant. The pressurizing container is required to withstand the pressure of the pressurized refrigerant and to seal it to prevent leakage of the refrigerant placed inside.

[0003] The pressurized container is made of metal or resin depending on the required characteristics, but for example, a portion such as a nipple provided on the pressurized container may be made of a metal insert member, and the container body of the pressurized container may be made of resin, and the two may be integrated by so-called insert injection molding. However, when the metal insert member and the resin container body are integrated by insert injection molding, the sealing performance at the interface where the insert member and the resin come into contact becomes poor, and gas or liquid is likely to leak from that area.

[0004] In order to improve the joining and sealing properties during insert injection molding of a metal insert member and a resin member (e.g., a container body), a technique is known in which the surface of the metal insert member is laser processed before the insert injection molding. For example, Patent Document 1 describes a method for manufacturing a composite member in which the surface of a metal insert member is laser processed to form multiple recesses with specific shapes on the surface of the insert member, and the surface is then bonded to a resin. It is disclosed that this method for manufacturing a composite member can produce a composite member with excellent bonding strength and airtightness. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-57584 Summary of the Invention [Problem to be solved by the invention]

[0006] In pressurized containers, imperfections in the seal at the joint between the metal insert member and the resin container body can result in insufficient pressurization or leakage of refrigerant, so reliable sealing at the joint is required. In particular, when pressurized containers are exposed to high or low temperatures during use, sealing is often difficult because the expansion / contraction of resin due to temperature changes is greater than the expansion / contraction of metal, and reliable sealing is particularly required in such applications.

[0007] An object of the present invention is to ensure a more reliable seal at the joint between the metal insert member and the resin molded body. [Means for solving the problem]

[0008] After careful consideration, the inventor discovered that sealing performance can be improved by adopting a combination of a tapered surface and an annular groove in the shape of the joint between the metal insert member and the resin molded body, and thus completed the present invention.

[0009] The present invention is a composite molded body in which a metal insert member having a cylindrical outer peripheral surface and a resin molded body formed from a thermoplastic resin are integrated together, and the insert member and the resin molded body are integrated by insert injection molding, and the resin injected during the insert injection molding covers an annular region, which is at least a part of the outer peripheral surface of the insert member, so that the resin adheres tightly to the annular region, and the annular region is provided with a conical tapered surface and annular groove, and the annular groove is arranged on the larger diameter side of the tapered surface (first invention).

[0010] In the first invention, preferably, the insert member is hollow tubular and has a through-hole that penetrates the inside of the annular region (a second invention). The present invention also provides a pressurization container integrated with the composite molded product of the first invention, wherein the insert member is provided so as to penetrate the inside and outside of the pressurization container, and the annular groove is provided on the inside of the pressurization container with respect to the tapered surface (a third invention). The present invention also provides a piping component integrated with the composite molded product of the second invention, wherein the insert member is a part of the piping (a fourth invention). [Effects of the Invention]

[0011] According to the composite molded body of the present invention (first invention), the pressurized container of the present invention (third invention), and the piping member of the present invention (fourth invention), the sealing properties of the joint between the metal insert member and the resin molded body can be more reliably achieved.

[0012] Furthermore, when the insert member is a hollow tubular member as in the second and fourth inventions, pressure and fluid can be transmitted through the through-hole while ensuring a secure seal. Also, when the second invention is used in a pressurized container, the inside of the container can be accessed from the outside of the container through the through-hole. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a cross-sectional view showing the configuration of a pressurizing container integrated with the composite molded body of the first embodiment. [Figure 2] FIG. 1 is a partial cross-sectional view showing the configuration of a composite molded body according to a first embodiment. [Figure 3] FIG. 3 is a schematic diagram showing the effect of the composite molded body of the first embodiment when exposed to low temperatures. [Figure 4] 3A to 3C are schematic diagrams showing the effect of the composite molded body of the first embodiment when exposed to high temperatures. [Figure 5]FIG. 6 is a partial cross-sectional view showing the configuration of a composite molded body according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, with reference to the drawings, an embodiment of the invention will be described using as an example a pressurizing container provided in a circulation path for circulating coolant in a cooling system of an internal combustion engine of an automobile. The invention is not limited to the specific embodiment shown below, and can be implemented by modifying the form. For example, as will be described later, the specific use of the pressurizing container may be other uses.

[0015] FIG. 1 shows a cross-sectional view of a pressurizing container 10 integrated with a composite molded body 2 of the first embodiment. The pressurizing container 10 is a hollow container integrated with the composite molded body 2 and a molded body 3. The composite molded body 2 is configured by integrating a metal insert member 11 and a resin molded body 12. The molded body 3 and the resin molded body 12 are each formed like a hollow container split in half, and the hollow container is configured by joining the two by means of adhesion, welding, or the like. The material of the molded body 3 and the method of joining it to the composite molded body 2 are not particularly limited, but preferably the molded body 3 is formed from a thermoplastic resin, and the composite molded body 2 and the molded body 3 are joined by heat welding.

[0016] The pressurizing container 10 is used by being connected to, for example, a circulation path for circulating cooling water so that the refrigerant can flow in and out through the metal insert member 11. Furthermore, when in use, the pressurizing container 10 is pressurized so that the internal space of the container is at a higher pressure than the external space.

[0017] Although not essential, in this embodiment, the metal insert member 11 is hollow tubular and has a through hole H. Through this through hole H, the refrigerant can be exchanged with the inside of the pressurizing container 10.

[0018] The resin molded body 12 constituting the composite molded body 2 is made of a thermoplastic resin. The thermoplastic resin is not particularly limited, but is preferably a resin that can be thermally welded, such as a polyamide resin, a polypropylene resin, or a polyethylene resin. The thermoplastic resin is not limited to a pure resin consisting of a single resin component, but may be a thermoplastic resin composition containing various compounded materials or other resin components.

[0019] Next, the metal insert member 11 that constitutes the composite molded body 2 will be described. As shown in FIG. 2, the insert member 11 has a cylindrical outer peripheral surface. It is sufficient that only a portion of the outer peripheral surface of the insert member is cylindrical. In this embodiment, the entire outer peripheral surface of the insert member 11 is cylindrical. The metal material that constitutes the insert member 11 is not particularly limited, but examples include metal materials such as aluminum, iron, and brass. The insert member 11 may also be plated.

[0020] The insert member 11 and the resin molded body 12 are integrated by insert injection molding. The resin injected during the insert injection molding covers at least a part of the outer peripheral surface of the insert member 11, the annular region CF, with the resin so that the injected resin adheres closely to the annular region CF.

[0021] Although not required, in this embodiment, a metal insert member 11 is placed inside the injection molding die that forms the resin molded body 12, and in that state the die is closed and the resin injection molding process is carried out, and while molding the resin molded body 12, insert injection molding is performed so that the resin molded body 12 and the insert member 11 are integrated, thereby obtaining a composite molded body 2.

[0022] That is, during insert injection molding, the injected resin is filled in a ring-shaped manner around a portion of the outer peripheral surface of the insert member 11 and then solidifies, and the portion covered by the injected resin is the ring-shaped region CF on the outer peripheral surface of the insert member 11.

[0023] The annular region CF of the metal insert member 11 is provided with a conical tapered surface 14 and annular groove 15. When the overall shape of the insert member 11 is hollow tubular, it is preferable, though not essential, to provide the conical tapered surface 14 and annular groove 15 while making the outer circumferential wall of the annular region CF larger (increased in diameter) than the general outer circumferential surface of the hollow tube. In this way, the strength, pressure resistance, etc. of the insert member 11 itself can be improved.

[0024] Furthermore, in the annular region CF of the metal insert member 11, the annular groove 15 is disposed on the larger diameter side of the tapered surface 14. For example, in the embodiment shown in FIG. 2, the metal insert member 11 is a hollow tube 13 outside the annular region CF, and in the annular region CF, the diameter of the outer circumferential surface gradually expands from a small diameter to a large diameter due to the tapered surface 14, with the annular groove 15 being provided adjacent to the larger diameter side. Preferably, the annular groove 15 is provided so that the portion where the cross section of the groove changes from a large diameter to a small diameter is approximately perpendicular to the central axis m of the cylindrical annular region CF. That is, the annular groove 15 is preferably provided in the shape of a rectangular groove.

[0025] Although not essential, the insert member 11 is preferably a hollow tubular insert member having a through hole H formed so as to penetrate the inside of the annular region CF, as in this embodiment. As in other embodiments described later, the insert member 11 may not have a through hole H.

[0026] Furthermore, although not essential, in this embodiment, the metal insert member 11 is provided in the pressurizing vessel 10 so as to penetrate the inside and outside of the vessel wall of the pressurizing vessel 10, and the annular groove 15 is provided on the inside of the pressurizing vessel relative to the tapered surface 14, i.e., on the side that becomes high pressure.

[0027] The following describes the operation and effect of the composite molded body 2 of the above embodiment. In the composite molded body 2, the annular region CF of the insert member 11 is covered by insert injection molding, and the resin and the insert member are tightly attached to form a seal, but the annular region CF of the insert member 11 is provided with a conical tapered surface 14 and annular groove 15, and the annular groove 15 is located on the large diameter side of the tapered surface 14, so that the sealing of the joint is more reliable.

[0028] In conventional technology, for example, when the joint surface between the insert member and the resin molded body is a simple cylindrical shape, when the composite molded body is cooled, the resin molded body contracts and tightens the metal insert member, thereby improving sealing performance. However, when the composite molded body is heated (exposed to high temperatures), the resin molded body expands more than the metal insert member, which weakens the tightening of the insert member by the resin molded body or creates a gap between the resin molded body and the insert member, thereby deteriorating sealing performance.

[0029] In addition, an annular groove has sometimes been provided on the joint surface between the insert member and the resin molded body, but the annular groove alone has not been able to improve sealing properties in an environment where such cooling and heating occur.

[0030] In the composite molded body 2 of the above embodiment, a tapered surface 14 and annular groove 15 are provided in the annular region CF, which becomes the joint by insert injection molding, and the annular groove 15 is arranged on the large diameter side of the tapered surface 14.As described below, therefore, whether the composite molded body 2 is being cooled or heated, there is sufficient adhesion between the resin and the metal insert, ensuring reliable sealing of the joint.

[0031] First, the cooling phase of the composite molded body 2 will be described with reference to FIG. When the composite molded body 2 is cooled, the resin molded body 12 shrinks more than the metal insert member 11. When the resin molded body 12 shrinks, the portion 12a surrounding the tapered surface 14 shrinks into a ring shape, and this shrinkage causes the portion 12a to tighten around the tapered surface 14. This action is represented by the right-pointing arrow in Figure 3.

[0032] Furthermore, in the resin molded body 12, the portion 12b that fits into the annular groove 15 of the insert member 11 is substantially fixed within the annular groove and does not move along the central axis m of the annular region CF. Therefore, when the composite molded body 2 is cooled and the resin molded body shrinks further, reducing the distance between the portions 12a and 12b of the resin molded body, the portion 12a shrinks as if being drawn toward the annular groove 15, because the portion 12b is fixed inside the annular groove 15. This action is represented by a downward arrow in Figure 3.

[0033] As described above, when the composite molded body 2 is cooled, the resin molded body 12 shrinks more than the insert member 11, resulting in the shrinkage actions shown by the rightward and downward arrows in Fig. 3. Both of these actions work to improve the adhesion between the tapered surface 14 of the metal insert member 11 and the resin portion 12a that covers that portion. Therefore, the composite molded body 2 of the above embodiment can obtain reliable sealing even when cooled.

[0034] Next, the phase in which the composite molded body 2 is heated will be described with reference to FIG. When the composite molded body 2 is heated, the resin molded body 12 expands more than the metal insert member 11. At this time, the portion 12b of the resin molded body 12 that fits into the annular groove 15 of the insert member 11 also expands in the direction along the central axis m of the annular region CF. This expansion is represented by the upward and downward arrows in Figure 4.

[0035] This expansion causes the portion 12b inserted into the annular groove 15 to be strongly pressed against the annular groove 15 in the vertical direction in Figure 4. This pressing maintains the seal line on the annular groove 15 side when heated, ensuring a reliable seal. Therefore, the composite molding 2 of the above embodiment provides reliable sealing even when heated.

[0036] Furthermore, when the composite molded body 2 is heated, the temperature of the metal insert member 11 rises first, followed by the temperature of the resin molded body 12. However, the portion 12b between the annular grooves 15 of the metal insert, which rises in temperature first, rises in temperature faster than the other portions of the resin molded body 12. As a result, the portion 12b expands and becomes locked within the annular groove, even though the entire resin molded body 12 has not yet expanded / expanded in diameter. This locking effect prevents the resin molded body from expanding in diameter, and prevents deterioration of the sealing performance when heated.

[0037] Furthermore, as part 12b expands and locks within the annular groove, part 12b acts as a strong anchor, preventing part 12a facing tapered surface 14 from shifting in the direction of extension of central axis m, and preventing deterioration of sealing performance when heated.

[0038] As described above, in the composite molding 2, the tapered surface 14 and the annular groove 15 are provided on the insert member 11 so that the annular groove 15 is located on the larger diameter side of the tapered surface 14, thereby ensuring reliable sealing both when heated and when cooled.

[0039] The inventors conducted an airtightness test on the joint between the insert member and the resin molded body using test pieces, and found that air leaks when pressurized when the insert member has a cylindrical outer circumferential surface or an insert member with only an annular groove on the cylinder. On the other hand, when the insert member is combined with the tapered surface 14 and the annular groove 15 as in the above embodiment, a composite molded body 2 that does not leak air even when pressurized was obtained.

[0040] Furthermore, as in the above embodiment, when the insert member 11 is hollow and tubular with the through-hole H provided so as to penetrate the inside of the annular region CF, the through-hole can communicate the inside and outside of the pressurization container 10, allowing the refrigerant inside to be introduced or discharged and the internal pressure to be detected. In other words, the inside of the pressurization container can be accessed from the outside of the container through the through-hole while ensuring a reliable seal.

[0041] Furthermore, as in the above embodiment, when the composite molded body 2, in which the insert member 11 and the resin molded body 12 are integrated, is integrated to become a part of the pressurized container 10 to form the pressurized container 10, the insert member 11 is arranged to penetrate the inside and outside of the pressurized container 10, and the annular groove 15 is arranged on the inside of the pressurized container relative to the tapered surface 14, i.e., on the side where high pressure occurs, the insert member 11 is forced toward the outside of the container by the high pressure inside the container, and this force presses the tapered surface 14 of the insert member against the part 12a of the resin molded body that surrounds the tapered surface, making the sealing action of that part more reliable.

[0042] The invention is not limited to the above-described embodiment, and various modifications can be made to the invention. Other embodiments of the invention will be described below, focusing on differences from the above-described embodiment, and detailed descriptions of similarities will be omitted. Furthermore, these embodiments can be implemented by combining parts of them with each other or by substituting parts of them.

[0043] 5 is a partial cross-sectional view showing the configuration of a composite molded body 5 of the second embodiment. The composite molded body 5 is similar to the first embodiment in that a metal insert member 21 and a resin molded body 23 are integrated by insert injection molding, and that a tapered surface 14 and annular groove 15 are provided in an annular region CF on the outer circumferential surface of the metal insert member 21, with the annular groove 15 being disposed on the larger diameter side of the tapered surface 14.

[0044] In this embodiment, the relationship between the resin molded body 23 and the insert injection molding is different from that in the first embodiment. In the first embodiment, a metal insert member 11 is placed inside an injection mold for insert injection molding, and insert injection molding is performed in this state, so that the resin molded body 12 and the insert member 11 are integrated at the same time as the resin molded body 12 is molded. On the other hand, in the manufacturing process of the composite molded body 5 of the second embodiment shown in Figure 5, the resin molded body 23 is prepared in advance by injection molding or the like, and then the resin molded body 23 and the metal insert member 21 are placed inside an injection molding die for insert injection molding, and insert injection molding is performed in which molten resin is injected into the gap between the two.The injected resin covers the annular region CF on the outer surface of the metal insert member 21, and the injected resin is integrated with the resin molded body 23 by welding or the like.The resin injected in the insert injection molding process forms an annular joint 22 that joins the metal insert member 21 and the resin molded body 23, and the composite molded body 5 is manufactured.

[0045] The relationship between the resin molded body 23 and the insert injection molding may be as in the first embodiment or as in the second embodiment. In either case, if the tapered surface 14 and the annular groove 15 are provided in the annular region CF on the outer circumferential surface of the metal insert member and the annular groove 15 is arranged on the larger diameter side of the tapered surface 14, the reliability of the seal is similarly improved.

[0046] In this embodiment, the entire outer circumferential surface of the metallic insert member 21 is an annular region CF that is covered with the resin injected during the insert injection molding. That is, the shape of the metallic insert member other than the annular region CF is not particularly limited.

[0047] In this embodiment, a through hole is provided in the metal insert member 21 so as to penetrate the insert member 21, and a thread is formed on the inner peripheral surface of the through hole. When the composite molded body 5 is used, for example, a bolt-shaped pressure sensor S can be attached using the thread of the through hole, and the pressure inside the container can be detected by the pressure sensor S. The sensor may also be a temperature sensor or the like.

[0048] As described above, the specific shape of the metal insert member, particularly the shape of the portion exposed to the outside of the resin molded body, is not particularly limited. For example, this portion can be shaped like a nipple for connecting a tube, or like a male / female pipe fitting for connecting a tubular body. Furthermore, as in the second embodiment, the metal insert member 21 may be shaped to serve as a base for attaching a sensor or the like. Furthermore, the metal insert member itself may be a sensor, a terminal, or the like. In this case, the metal insert member does not need to have a through-hole.

[0049] The metal insert may also be provided with a knurled portion, a polygonal portion, or a gear-shaped portion to prevent rotation when the screw is tightened. These portions are preferably provided so as to be covered with the insert injection molded resin. These portions are also provided apart from the tapered surface and annular groove in the above embodiment.

[0050] In the above embodiment, the side surfaces of the cylindrical or rod-shaped metal insert member are mainly covered with the resin injected during insert injection molding. However, the end surfaces of the metal insert member, such as the upper and lower end surfaces of a cylindrical metal insert member, may also be covered with the resin injected during insert injection molding. This configuration increases the bonding strength between the metal insert member and the resin molded body. Furthermore, if a ring-shaped groove is formed on the end surface of the metal insert member, and the resin injected during insert injection molding also contacts the resin and the metal insert member through the groove, this is preferable because it further improves the reliability of the seal.

[0051] Furthermore, in the manufacture of the composite molded article of the above embodiment, when the metal insert member is subjected to insert injection molding, it may be subjected to a surface treatment to improve adhesion between the resin and the metal or a treatment to improve sealing properties before being subjected to insert injection molding. For example, the surface of the metal insert member may be laser processed to create irregularities, the surface of the metal insert member may be roughened by treating it with a chemical or the like, or the metal insert member may be subjected to a binder treatment to improve adhesion between the metal insert member and the resin injected during insert injection molding.

[0052] Although not described in the above embodiment, the composite molded body 2 and the pressurizing vessel 10 may be provided with an inlet for a refrigerant (cooling liquid), a mounting stay, a boss, etc., as needed.

[0053] In the above embodiment, the composite molded body, in which the metal insert member and the resin molded body are integrated, is described as being used as an integrated part of a pressurized container. However, the use of the composite molded body is not limited to pressurized containers. For example, the composite molded body can also be used in a container in which the internal pressure is reduced. Furthermore, the composite molded body may be used as a partition disposed inside the container, rather than as a peripheral wall of the container. Furthermore, the composite molded body may be used as part of a pipeline through which a pressurized fluid flows.

[0054] Furthermore, in the above-described embodiments, examples have been described in which the composite molded body 2 and the pressurizing container 10 are connected to a refrigerant flow path in a cooling system for an automobile internal combustion engine. However, the uses of the composite molded body 2 and the pressurizing container 10 are not limited to this, and the composite molded body 2 and the pressurizing container 10 of the above-described embodiments can be used in any application requiring sealing in a differential pressure environment. For example, the composite molded body 2 and the pressurizing container 10 may be connected to a path for circulating a refrigerant in a temperature control system for cooling and heating a secondary battery. In particular, even in systems where the system in which they are used involves temperature changes, the composite molded body 2 and the pressurizing container 10 of the above-described embodiments exhibit excellent sealing properties and are suitable for use.

[0055] Furthermore, a composite molded product in which a metal insert member and a resin molded product are integrated may be used as a piping component. Here, the piping component refers to a component used in piping, such as a pipe joint, a pipe, a tube, a branch pipe, a manifold, or a pressure adjusting member. The piping component may be, for example, a composite molded product in which a metal insert member shaped like a male member of a pipe joint is integrated with a soft resin molded product (e.g., a resin tube). In this case, a through hole is provided in the metal insert member so that it becomes part of the piping.

[0056] Furthermore, when the composite molded body is used as a piping member and the piping member is a pressurized piping member used in piping that is pressurized, it is preferable that the annular region in which the insert member and the resin molded body come into contact is configured so that the annular groove is inside the pressurized piping member relative to the tapered surface. [Industrial Applicability]

[0057] The composite molded body and pressurizing container of the above embodiment can be used in the refrigerant passage of the cooling system of an automobile or the like, and has high industrial applicability due to its improved sealing properties. [Explanation of symbols]

[0058] 10 Pressurized container 2 Composite molded body 11 Metal insert member 13 Hollow tube CF annular region 14 Tapered surface 15 Annular groove 12 Resin molding 12a, 12b part 3. Molded body 5 Composite molded body 21 Metal insert member 22 Joint 23 Resin molding S pressure sensor

Claims

1. A composite molded body in which a metal insert member having a cylindrical outer peripheral surface and a resin molded body formed from a thermoplastic resin are integrated, the insert member and the resin molded body are integrated by insert injection molding, and an annular region, which is at least a part of the outer circumferential surface of the insert member, is covered with resin injected during the insert injection molding so as to be in close contact with the resin; The annular region is provided with a conical tapered surface and an annular groove, An annular groove is disposed on the large diameter side of the tapered surface. Composite molded body.

2. The insert member is a hollow tube having a through hole formed therethrough to penetrate the inside of the annular region. The composite molding according to claim 1 .

3. A pressurizing container in which the composite molded article according to claim 1 is integrated, the insert member is provided so as to penetrate the inside and outside of the pressurizing container, the annular groove is provided on the inner side of the pressurizing vessel with respect to the tapered surface; Pressurized container.

4. A piping part in which the composite molding according to claim 2 is integrated, The insert member is a part of the piping. Piping parts.

Images