JP2012193751A - Method for mounting hollow member and fastening member, and mounting structure - Google Patents

Abstract

To provide a hollow member and a fastening member mounting method capable of securely and securely mounting a fastening member to a hollow member in an easy manner while suppressing an increase in the number of parts and the number of assembly steps.
An absorptive material that has an insertion hole and has a hollow member made of a transparent material that transmits laser light, and an insertion portion that can be inserted into the insertion hole, and absorbs laser light. A first step of preparing a fastening member 20 made of a thermoplastic material, a second step of inserting the insertion portion 12 of the fastening member 20 into the hollow member 10 through the insertion hole 5, The end portion 13 of the insertion portion 12 inserted inside the hollow member 10 is melted by irradiating the laser beam R from the outside of the hollow member 10 and the insertion portion 12 is pressed against the inner peripheral surface 4 of the hollow member 10 for insertion. This is a third step of forming a flange portion 14 relatively larger than the hole 5 in the insertion portion 12.
[Selection] Figure 1

Description

  The present invention relates to a mounting method and a mounting structure for a hollow member and a fastening member.

  2. Description of the Related Art Conventionally, ribs, box structures, and the like as reinforcing materials have been provided on the back surfaces of interior parts and exterior parts of vehicles in order to increase the rigidity of the parts and suppress deformation due to heat. In particular, a box structure (hollow structure) having a closed space has a structure that can withstand a load from multiple directions with respect to a rib or the like, thereby effectively increasing the rigidity of the component.

  Further, a fastening member such as a clip is attached to the back surface of these parts, and the interior part and the exterior part are attached to an inner panel, a door panel, a bumper beam and the like constituting the body by the fastening member. For example, as a method of attaching a fastening member to a box structure (hollow structure) having a closed space provided on the back surface of the component, a method of bolting the fastening member using a separate fastening member such as a tapping screw or a bolt, And a method of welding a base (clip base) of a fastening member, a method of adhering a base of a fastening member using an adhesive such as a double-sided tape, and the like.

  Here, with reference to FIG. 7, a conventional method of attaching a hollow member and a fastening member, particularly a method of attaching a fastening member such as a clip to the hollow member using a tapping screw will be described. First, as shown in FIG. 7A, for example, a hollow member A having a honeycomb structure and a fastening member (clip) C having a pedestal D and a head E are prepared and penetrated into one side wall of the hollow member A. Hole B is formed. Here, the position of the through hole B corresponds to a mounting position of a screw G described later. A through hole F through which the screw G can penetrate is also provided in the base D of the fastening member C. Next, as shown in FIG. 7B, the fastening member C is disposed at the attachment position of the hollow member A. Then, as shown in FIG. 7C, the screw G is passed through the through hole F of the base D of the fastening member C and the through hole B of the hollow member A, and the fastening member is connected with the head H of the screw G and the hollow member A. C pedestal D is clamped.

  According to the conventional mounting method using screws, bolts and the like shown in FIG. 7, in addition to the hollow member A and the fastening member C, a separate fastening member such as a screw G is required, and the number of parts is increased and the weight of the vehicle is reduced. I can't plan. Moreover, there is a possibility that the manufacturing cost will increase due to an increase in the number of assembling steps by the screw G of the fastening member C. Further, when the fastening member C is attached to the surface side (design surface) of the interior part or the exterior part, the screw G is exposed to the surface side of these parts, so that the appearance may be impaired. Further, when the hollow member A vibrates with the vibration of the vehicle that occurs when the vehicle travels, a separate fastening member such as a screw G is gradually loosened, and the fastening force is reduced, causing damage to parts and generation of abnormal noise. There is also a problem that becomes a factor. As a means for suppressing such loosening, for example, a method using a screw locking agent, a method using a washer for preventing loosening, a method using a non-locking screw in which a part of a thread is deformed can be applied. . However, all of these methods require additional members or special processing of the screws, leading to an increase in vehicle weight and a further increase in manufacturing costs.

  Further, according to the method of welding the base of the fastening member to the hollow member, when stress is generated in the welded portion due to vehicle vibration or the like, the welding of the base is peeled off and the fastening member can be detached from the hollow member. There is sex. Although the stress generated in the welded portion can be reduced by increasing the welded area, this method increases the weight of the fastening member and thus inhibits the weight reduction of the entire vehicle. Further, in the method of bonding the base of the fastening member to the hollow member with an adhesive, the adhesive strength of the adhesive may be drastically reduced due to deterioration over time in a vehicle or the like used in various environments. There is a possibility that the bonding by the adhesive peels off before the years elapse and the fastening member falls off the hollow member.

  In contrast to the above method, Patent Documents 1 and 2 disclose a method of attaching a member made of resin or metal to another member by reducing the number of parts or the number of assembly steps without using a separate fastening member that may be loosened. It is disclosed.

  In Patent Document 1, a pin-shaped protrusion made of an aluminum-based material is fitted into a hole of a terminal cap made of an iron-based material, and a tip portion of the pin-shaped protrusion is crushed to form a rivet fixing portion that fixes the pin-shaped protrusion and the hole to a rivet. And the method of welding a rivet fixing part by irradiating a laser beam to the wall surface of the hole of the terminal cap near this rivet fixing part is disclosed.

  Further, in Patent Document 2, a convex portion formed on a non-transparent resin member for laser light is fitted into a concave portion formed on a resin member transparent to laser light, and the convex portion is formed from the transparent resin member side. A method is disclosed in which both members are welded and fixed by irradiating a laser beam to melt the convex portion.

JP 2010-087882 A JP-A-2005-007759

  In the mounting method disclosed in Patent Document 1, a rivet fixing portion that is relatively larger than the hole of the terminal cap can be formed on the pin-like protrusion, but the tip portion of the pin-like protrusion needs to be crushed using a rivet fixing tool. And cannot be applied to attachment of a fastening member to a hollow member made of a closed space such as a ham cam. In addition, a large pressing load is required to crush the tip before irradiating the laser beam, and the terminal cap may be deformed.

  Further, in the method disclosed in Patent Document 2, although the resin members can be welded even in a closed space, the concave portion and the convex portion are bonded by surface bonding, and sufficient mounting strength is guaranteed. I can't. Patent Document 2 discloses that in order to improve airtightness and adhesive strength, a recess is provided in the concave portion of the permeable resin member, and a bead-shaped protrusion is provided in the convex portion of the non-permeable resin member. When a convex portion having such a bead-shaped projection is arranged in the concave portion, a large pressing load is required until the projection comes into contact with the side wall of the concave portion and the projection is arranged at a predetermined position. .

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and a hollow member and a fastening member that can attach a fastening member to a hollow member with an easy method while suppressing an increase in the number of parts and assembly steps. It is an object of the present invention to provide a mounting structure for a fastening member and a hollow member to which a fastening member is attached with a light weight and high fastening strength.

  In order to achieve the above object, the hollow member and fastening member mounting method according to the present invention includes a hollow member having an insertion hole and made of a transparent material that transmits laser light, and an insert that can be inserted into the insertion hole. A first step of preparing a fastening member having a portion, and at least the insertion portion is an absorptive material that absorbs laser light and is made of a thermoplastic material, and the inside of the hollow member through the insertion hole A second step of inserting the insertion portion of the fastening member into the hollow member, and melting the end portion of the insertion portion inserted into the hollow member by irradiating a laser beam from the outside of the hollow member. This is composed of a third step of pressing a part of the inner peripheral surface of the hollow member to form a flange portion relatively larger than the insertion hole in the insertion portion.

  Here, examples of the material for forming the hollow member include polypropylene (PP), polyacetal (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycarbonate (PC), and liquid crystal polymer. The material for forming the hollow member may be a thermoplastic resin or a thermosetting resin.

  Examples of the material for forming the fastening member include polybutylene terephthalate (PBT), polycarbonate (PC), polyamide 6 (PA6), polyphenylene sulfide (PPS), and the like. In addition, in order to absorb laser light and promote heat generation, these resins may be formed from a material in which an inorganic or organic additive such as carbon black or a flame retardant is added.

  According to the mounting method described above, a separate fastening member such as a screw is not required, and the number of parts and assembly man-hours can be reduced. Further, the end of the insertion portion inserted into the hollow member is melted by irradiating laser light from the outside of the hollow member, and the molten insertion portion is pressed against a part of the inner peripheral surface of the hollow member. Thus, the pressing load on the inner peripheral surface of the hollow member can be suppressed, and the flange portion can be easily formed at the end of the insertion portion while suppressing deformation of the hollow member. In addition, by pressing the melted portion to form a flange portion that is relatively larger than the insertion hole, a separate tool for pressing the insertion portion becomes unnecessary, and even in a closed space such as a hollow member The flange portion can be easily formed. Furthermore, since the flange portion larger than the insertion hole is formed in the insertion portion, it is possible to reliably prevent the fastening member from dropping from the hollow member, and to improve the fixing reliability of the fastening member to the hollow member. it can.

  Further, in the third step, an embodiment in which the end portion of the insertion portion is brought into contact with a part of the inner peripheral surface of the hollow member and then the end portion is irradiated with laser light is preferable. . According to this aspect, the laser light irradiation time can be shortened, and the cost required for the fastening member attaching step can be suppressed.

  Further, in the third step, the end portion of the insertion portion is pressed against the inner peripheral surface of the hollow member while irradiating the end portion with laser light, thereby suppressing the hardening of the insertion portion during pressing. It is possible to suppress the increase of the pressing load in the attachment process, and it is possible to easily form a uniform flange portion at the end portion of the insertion portion.

  Moreover, in the mounting method described above, an embodiment that further includes a fourth step of separating the flange portion of the fastening member and a part of the inner peripheral surface of the hollow member to solidify the flange portion is preferable. . For example, if the flange portion is cooled and solidified in a state where the flange portion is in contact with the hollow member, sink marks are generated on the surface of the hollow member in contact with the flange portion due to thermal contraction of the flange portion. There is a high possibility of doing. Therefore, by the fourth step, the flange portion is separated from the inner peripheral surface of the hollow member and solidified, thereby suppressing the occurrence of sink marks on the surface of the hollow member where the insertion portion of the fastening member is pressed. The excellent appearance (design surface) of the hollow member can be guaranteed.

  Moreover, in the mounting method described above, an embodiment further including a fifth step of engaging the solidified flange portion with the other portion of the inner peripheral surface of the hollow member is preferable. According to the fifth step, the fastening member can be engaged with and fixed to the hollow member. For example, when the hollow member is attached to another member such as a vehicle body panel using the fastening member. The movement of the fastening member relative to the hollow member can be suppressed, and the hollow member can be attached to another member easily and reliably.

  Here, the hollow member may be divided into a plurality of cells by at least one partition wall, and the insertion hole may be provided in at least one of the cells. Examples of the cross-sectional shape of the cell include a honeycomb shape, a polygonal shape such as a triangle and a quadrangle, a circular shape, and an elliptical shape.

  Furthermore, an embodiment in which a difference in solubility parameter between the hollow member and the insertion portion of the fastening member is 1.0 or more is preferable.

  Here, the “solubility parameter (SP value)” is a measure for determining the solubility of the binary solution, for example, the ease of mixing the solute and the solvent, and substances having similar solubility parameters are likely to be mixed. It is known to have properties. For example, in the regular solution theory, the force acting between the solvent and the solute is modeled as only the intermolecular force, and therefore, the interaction causing the liquid molecules to aggregate can be considered to be only the intermolecular force. Since the liquid cohesive energy ΔE and the evaporation enthalpy (molar evaporation heat) ΔH are in a relationship of ΔH = ΔE + PΔV, the solubility parameter δ is calculated from the evaporation enthalpy ΔH and the molar volume V as follows: It is defined by equation (1).

Here, R is a gas constant = 8.331447 J / K · mol, T is the liquid temperature, and the SP value is the square root of the heat of vaporization (cal / cm ³ ) required for evaporation of 1 cm ³ of liquid ^. It is calculated from ⁵ .

  For example, if the insertion portion of the hollow member and the fastening member is incompatible, the two members do not mix, and the flange portion of the fastening member and the inner peripheral surface of the hollow member are separated in the fourth step. In addition, both can be easily separated. However, even if the insertion part of the hollow member and the fastening member is compatible, the compatibility thereof is low, and if the difference in the solubility parameter between the hollow member and the insertion part of the fastening member is 1.0 or more, the fourth In the process, the insertion portion of the hollow member and the fastening member can be separated by interfacial peeling, and the base material destruction of the hollow member and the fastening member during separation can be reliably prevented.

  Further, the present invention extends to a mounting structure for a fastening member and a hollow member in which the fastening member is attached to the hollow member. The hollow member has an insertion hole and is made of a transmissive material that transmits laser light, and the fastening member has an insertion portion, and at least the insertion portion is an absorptive material that absorbs laser light and is heated. It is made of a plastic material, and at least a part of the insertion portion of the fastening member is accommodated in the hollow member through an insertion hole of the hollow member, and the accommodating portion is accommodated in the hollow member. An end portion of the insertion portion includes a flange portion that is melted by laser light irradiation from the outside of the hollow member and is relatively larger than the insertion hole formed by pressing against a part of the inner peripheral surface of the hollow member. It is what.

  According to the mounting structure of the hollow member and the fastening member of the present embodiment, a separate fastening member for attaching the fastening member to the hollow member becomes unnecessary, an increase in the number of parts is suppressed, and the weight of the vehicle or the like is reduced. be able to. Moreover, high fastening strength can be ensured by the flange part formed in the edge part of an insertion part, and the fixation reliability of the fastening member with respect to a hollow member can be improved. Furthermore, a separate fastening member such as a screw is not exposed on the surface, and an excellent appearance (design surface) can be guaranteed.

  As can be understood from the above description, according to the mounting method and the mounting structure of the hollow member and the fastening member of the present invention, it is possible to reduce the weight and simplify the manufacturing process by suppressing the increase in the number of parts. Furthermore, the fastening strength of the hollow member and the fastening member can be increased by forming the flange portion in the insertion portion.

It is a figure explaining the attachment method of the hollow member and fastening member of this invention, (a) is the figure which showed the 1st process of preparing a hollow member and a fastening member, (b) is the 1st process. FIG. 9C is a diagram showing a second step of inserting the insertion portion through the insertion hole, and (c) is a step of irradiating the end of the insertion portion with laser light following the second step. It is the figure which showed the 3rd process which melts and presses an insertion part on the internal peripheral surface of a hollow member, and forms a flange part. It is an AA arrow directional view of the hollow member shown to Fig.1 (a). It is the figure which showed the 4th process of separating the flange part and hollow member of a fastening member, and solidifying a flange part following the 3rd process shown in FIG.1 (c). FIG. 10 is a view showing a fifth step of engaging the solidified flange portion with the other portion of the inner peripheral surface of the hollow member following the fourth step shown in FIG. 3. It is the perspective view which showed the test piece supposing the hollow member and the fastening member. It is the figure which showed the relationship between the difference of SP value of a hollow member and a fastening member, and welding strength. It is a figure explaining the attachment method of the conventional hollow member and a fastening member, (a) is a figure explaining the process of preparing a hollow member and a fastening member, (b) is a fastening member in the attachment position of a hollow member. It is a figure explaining the process of arrange | positioning, (c) is a figure explaining the process of attaching a fastening member to a hollow member with a screw.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram illustrating a method for attaching a hollow member and a fastening member according to the present invention, and FIG. 1 (a) is a diagram illustrating a first step of preparing the hollow member and the fastening member. b) is a diagram showing a second step of inserting the insertion portion through the insertion hole following the first step, and FIG. 1C is a drawing of the insertion portion following the second step. It is the figure which showed the 3rd process of irradiating a laser beam to the edge part of this, melt | dissolving, and pressing an insertion part on the internal peripheral surface of a hollow member, and forming a flange part. Moreover, FIG. 2 is an AA arrow view of the hollow member shown in FIG.

  First, as shown in FIG. 1A, a hollow member 10 made of a transparent material that transmits laser light, and a fastening member made of a thermoplastic material that absorbs laser light and is made of a thermoplastic material (for example, a clip). 20 is prepared (first step).

  As shown in the figure, the hollow member 10 has a side wall 1 on one side and a side wall 2 on the other side opposite to the side wall 1, and the side wall 1 and the side wall 2 partition the internal space of the hollow member 10. 3, one cell 9 is formed in the internal space of the hollow member 10. Further, an insertion hole 5 is provided in a substantially central portion of the side wall 1 on one side. In addition, about the insertion hole 5 of the hollow member 10, it can pierce in the side wall 1 of the hollow member 10 provided with closed space beforehand using cutting tools, such as a drill, prior to a 1st process.

  The fastening member 20 has a head portion 11 and an insertion portion 12, and the head portion 11 is used when attached to another member such as a body panel which is a body constituting member. The insertion portion 12 has a size and a shape that can be inserted into the insertion hole 5 of the hollow member 10. The length L2 of the insertion portion 12 (the length excluding the head 11 of the fastening member 20) is at least longer than the depth L1 of the hollow member 10 in the insertion direction.

  The hollow member 10 shown in FIG. 1A has a honeycomb structure in which the cross-sectional shape of the cells 9 is hexagonal as shown in FIG.

  Subsequent to the first step described above, as shown in FIG. 1B, the insertion portion 12 of the fastening member 20 is inserted into the insertion hole 5 while holding the head portion 11 of the fastening member 20 by, for example, a holding means (not shown). Is inserted into the hollow member 10 (in the direction of the arrow X1) (second step).

  After the end portion 13 of the insertion portion 12 is brought into contact with the inner peripheral surface 4 of the side wall 2 of the hollow member 10, it is disposed outside the side wall 2 on the other side of the hollow member 10 as shown in FIG. From the laser oscillator 50, the infrared laser light R is irradiated to the end portion 13 of the insertion portion 12 that is transmitted through the side wall 2 of the hollow member 10 and inserted into the hollow member 10. Then, the insertion portion 12 that has absorbed and melted the laser light R is pressed against the inner peripheral surface 4 of the side wall 2 of the hollow member 10 by, for example, a holding means (not shown), and has a relatively larger outer diameter than the insertion hole 5. The flange portion 14 is formed (third step). In addition, after inserting a part of insertion part 12 into the inside of the hollow member 10, before making the edge part 13 of the insertion part 12 contact | abut with the internal peripheral surface 4 of the side wall 2 of the hollow member 10, the cell of the hollow member 10 is used. It is also possible to melt the insertion portion 12 by irradiating the end portion 13 of the insertion portion 12 inserted into the laser beam 9 with a laser beam.

  In the third step, the laser oscillator 50 is stopped when the insertion portion 12 is pressed against the side wall 2 of the hollow member 10, and the insertion portion 12 is thermally deformed using the residual heat of the molten insertion portion 12. Thus, the flange portion 14 can be formed. In addition, when the molten insert portion 12 is pressed against the side wall 2 of the hollow member 10, the laser insert 50 can irradiate the laser beam R to hold the melted insert portion 12 in a high temperature state. A uniform flange portion 14 can be formed.

  In this way, by pressing the melted insertion portion 12 against the inner peripheral surface 4 of the hollow member 10 to form the flange portion 14, the pressing load on the inner peripheral surface 4 of the hollow member 10 can be suppressed while suppressing the pressing load of the insertion portion 12. The flange portion 14 can be easily formed on the end portion 13. In addition, since the flange portion 14 that is relatively larger than the insertion hole 5 is formed in the insertion portion 12, it is possible to reliably prevent the fastening member 20 from falling off the hollow member 10, and to fasten the hollow member 10. The fixing reliability of the member 20 can be improved.

  Note that the end portion 13 of the insertion portion 12 can be efficiently melted by irradiating the laser beam R perpendicularly to the end portion 13 of the insertion portion 12 by the laser oscillator 50. Further, by scanning the laser oscillator 50 and irradiating the laser beam R from many directions of the insertion portion 12, the insertion portion 12 can be melted more uniformly and the uniform flange portion 14 can be formed. Further, a plurality of laser oscillators 50 may be arranged, and the laser beam R may be irradiated simultaneously from various angles of the insertion portion 12.

  Next, FIG. 3 is a view showing a fourth step of solidifying the flange portion by separating the flange portion and the hollow member of the fastening member following the third step shown in FIG.

  For example, as shown in FIG. 1C, when the inserted portion 12 melted in a posture in which the insertion portion 12 of the fastening member 20 is in contact with the side wall 2 of the hollow member 10 is cooled and solidified, the surface of the side wall 2 of the hollow member 10. In some cases, sinks may occur due to thermal contraction when the molten insertion portion 12 is solidified. Therefore, after forming the flange portion 14 in the third step, the laser transmitter 50 is stopped, and as shown in FIG. 3, the fastening member 20 is moved in the arrow X2 direction in a state where the flange portion 14 of the fastening member 20 is melted. The flange portion 14 is separated from the inner peripheral surface 4 of the side wall 2 of the hollow member 10 to cool and solidify the flange portion 14 (fourth step). In addition, as a cooling method of the flange part 14, cooling by natural heat dissipation, cooling by a cooler, etc. are applicable, for example.

  Here, if the difference in the solubility parameter (SP value) between the insertion portion 12 of the fastening member 20 and the hollow member 10 is large, the flange portion 14 of the fastening member 20 can be removed without destroying the hollow member 10 or the fastening member 20. Interfacial peeling can be performed from the inner peripheral surface 4 of the side wall 2 of the hollow member 10.

  Thus, after separating the inner peripheral surface 4 and the flange portion 14 of the side wall 2 of the hollow member 10, the hollow portion 10 and the fastening member 20 are made of resin materials having different cooling rates by cooling and solidifying the flange portion 14. Even if it is the case where it is done, generation | occurrence | production of the sink of the surface of the side wall 2 of the hollow member 10 can be prevented reliably. Further, by increasing the difference in SP value between the insertion portion 12 of the fastening member 20 and the hollow member 10, deformation and breakage of the hollow member 10 during separation can be reliably prevented, and the excellent appearance of the hollow member 10 (Design surface) can be guaranteed.

  In order to prevent the sink of the surface of the side wall 2 of the hollow member 10 more reliably, the distance D1 between the flange portion 14 after separation and the inner peripheral surface 4 of the side wall 2 is 0.1 mm or more. Is preferred.

  Further, by separating the flange portion 14 from the inner peripheral surface 4 of the side wall 2 of the hollow member 10 while irradiating the laser beam, solidification of the flange portion 14 at the time of separation can be surely prevented. The occurrence of sink marks on the surface of the side wall 2 can also be effectively suppressed.

  Thus, the end portion 13 of the insertion portion 12 melted by the laser light irradiation is cooled and solidified, and the attachment structure of the hollow member 10 and the fastening member 20 in which the fastening member 20 is attached to the hollow member 10 is formed. This attachment structure is now attached to, for example, an inner panel, a door panel, a bumper beam, or the like constituting the body.

  FIG. 4 illustrates a step of engaging the flange portion 14 cooled and solidified in the fourth step with the peripheral portion 6 around the insertion hole 5 of the side wall 1 of the hollow member 10.

  The insertion portion 12 (flange portion 14) of the fastening member 20 attached to the hollow member 10 by the third step shown in FIG. 3 can freely move within the cell 9 of the hollow member 10. Therefore, as shown in FIG. 4, the engaging portion 7 having elasticity is formed in advance on the side wall 1 of the hollow member 10, and the fastening member 20 is further moved in the direction of the arrow X <b> 3, so that the flange portion 14 of the fastening member 20. Is sandwiched between the side wall 1 of the hollow member 10 and the engaging portion 7, and the flange portion 14 of the fastening member 20 is engaged with and fixed to the peripheral portion 6 around the insertion hole 5 of the side wall 1 of the hollow member 10 (fifth). Process).

  According to the fifth step, the fastening member 20 can be fixed and attached to the hollow member 10, and the movement of the fastening member 20 with respect to the hollow member 10 can be suppressed. Therefore, for example, in the vehicle assembly process, the head 11 of the fastening member 11 attached to the hollow member 10 can be easily and reliably attached to, for example, a through-hole provided in an inner panel, a door panel, a bumper beam, etc. It is possible to simplify the work of attaching the mounting structure of the hollow member 10 and the fastening member 20 to the vehicle.

  In addition, by setting the distance D2 between the inner peripheral surface 4 of the side wall 2 of the hollow member 10 and the flange portion 14 of the fastening member 20 to about 0.1 to 0.2 mm, additional engagement means such as the engagement portion 7 can be provided. Without using it, the movement (rattle) of the fastening member 20 of the mounting structure can be suppressed within a range that does not hinder the mounting operation on the vehicle.

  In addition, about the cross-sectional shape of the side walls 1 and 2 and the partition 3 of the hollow member 10 shown by FIG.1, 3,4, it is not limited to the said form, At least any one can be formed in a curved-surface shape. For example, all of the side walls 1 and 2 and the partition wall 3 can be continuously formed in a curved shape, and the cross-sectional shape of the cell 9 of the hollow member 10 can be made substantially circular.

[Experiment and result on welding strength of hollow member and fastening member]
In order to identify the resin material suitable for the hollow member and the fastening member, the present inventors conducted a tensile test on Comparative Examples 1 and 2 and Examples 1 to 3 prepared by the following procedure, and the welding strength thereof. (Tensile strength) and fracture mode were measured.

  First, using the four types of resin materials shown in Table 1, both test pieces assuming a hollow member and a fastening member were prepared. Here, as a material for forming the hollow member, polypropylene (PP) and polybutylene terephthalate (PBT) having a relatively small SP value were used. A 1 mm thick test piece 31 was prepared assuming the other side wall of the hollow member. Moreover, as a forming material of a fastening member, four types of materials shown in Table 1 (polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), and polyamide (PA6)) were used. A test piece 32 having a thickness of 3 mm was prepared assuming the insertion portion of the fastening member (see FIG. 5A).

  Then, out of the test pieces of both the hollow member and the fastening member prepared above, the test pieces having the same SP value or a small difference in SP value were selected to produce Comparative Examples 1 and 2. As shown in Table 2, in Comparative Example 1, the material for forming the test pieces of both the hollow member and the fastening member is PP. In Comparative Example 2, the material for forming the test piece for the hollow member is PBT, and the material for forming the test piece for the fastening member is PC.

  Moreover, Examples 1-3 were produced by selecting a test piece having a relatively large difference in SP value from the test pieces of both the hollow member and the fastening member prepared above. In all of Examples 1 to 3, the material for forming the test piece of the hollow member is PP. In addition, the forming material of the test piece of the fastening member is PBT in Example 1, PC in Example 2, and PA6 in Example 3.

  The difference in SP value between the test piece of the hollow member and the test piece of the fastening member in Comparative Examples 1 and 2 is 0.0 and 0.1, respectively. Moreover, the difference of SP value of the test piece of the hollow member of Examples 1, 2, and 3 and the test piece of a fastening member is 1.0, 1.1, and 4.5, respectively.

  In preparing Comparative Examples 1 and 2 and Examples 1 to 3, a 1 mm thick test piece 31 assuming the other side wall of the hollow member and a 3 mm thickness test piece 32 assuming an insertion portion of a fastening member. After pressing the test piece 32 of the fastening member against the test piece 31 of the hollow member at 1.1 MPa, the focal point is taken from the semiconductor laser oscillator manufactured by Roffin Corporation disposed on the opposite side of the test piece 31. The end portion 33 of the test piece 32 was irradiated with laser light so that the diameter was 5 mm, and a flange portion 34 having a width of about 5 to 6 mm was formed on the end portion 33 of the melted test piece 32 (FIG. 5 ( b)).

  About the comparative examples 1 and 2 and Examples 1-3 produced by the said procedure, the tension test was implemented to the arrow Y direction shown in FIG.5 (b), and the welding strength (tensile strength) and the fracture | rupture form were measured. The results are shown in Table 2.

  As shown in Table 2, in Comparative Examples 1 and 2, the SP values of the test pieces of the hollow member and the fastening member are the same or the difference between the SP values of the two members is small. It was confirmed that the test piece on the hollow member side after the test was broken. Further, the welding strength (tensile strength) at that time was 30 MPa and 40 MPa, respectively.

  In Examples 1 to 3, since the difference in SP value between the test pieces of the hollow member and the fastening member is large, both the test pieces are not welded even after laser beam irradiation, and both tests are performed in the tensile test. It was confirmed that the pieces were peeled at the interface. In addition, in the tensile test, since both test pieces were able to isolate | separate almost without applying a tensile force, the welding strength was not confirmed.

  FIG. 6 is a diagram showing the relationship between the SP value difference between the test pieces of the hollow member and the fastening member and the welding strength. As shown in the figure, if the difference in SP value between the test pieces of the hollow member and the fastening member is 1.0 or more, both test pieces are not welded to each other. It has been demonstrated that the specimens can be separated from each other. That is, when the difference in SP value between the hollow member and the fastening member is 1.0 or more, in the fourth step shown in FIG. 3, when the flange portion of the fastening member is separated from the inner peripheral surface of the side wall of the hollow member. It has also been demonstrated that both members can be separated without deforming or damaging the hollow member or the fastening member.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

DESCRIPTION OF SYMBOLS 1, 2 ... Side wall, 3 ... Partition, 4 ... Inner peripheral surface, 5 ... Insertion hole, 9 ... Cell, 10 ... Hollow member, 11 ... Head, 12 ... Insertion part, 13 ... End part, 14 ... Flange part, DESCRIPTION OF SYMBOLS 20 ... Fastening member, 31 ... Test piece of hollow member, 32 ... Test piece of fastening member, 50 ... Laser oscillator, R ... Laser

Claims (8)

A mounting method for a hollow member and a fastening member,
A hollow member having an insertion hole and made of a transparent material that transmits laser light and an insertion part that can be inserted into the insertion hole, and at least the insertion part is an absorbing material that absorbs laser light. A first step of preparing a fastening member made of a thermoplastic material;
A second step of inserting the insertion portion of the fastening member into the hollow member through the insertion hole;
The end portion of the insertion portion inserted into the hollow member is irradiated with a laser beam from the outside of the hollow member to be melted, and the insertion portion is pressed against a part of the inner peripheral surface of the hollow member. A method for attaching a hollow member and a fastening member, comprising a third step of forming a flange portion relatively larger than the insertion hole in the insertion portion.   The hollow member according to claim 1, wherein, in the third step, the end portion of the insertion portion is brought into contact with a part of the inner peripheral surface of the hollow member, and then the end portion is irradiated with laser light. And attachment method of the fastening member.   The said 3rd process WHEREIN: While pressing the said edge part of the said insertion part to the said internal peripheral surface of the said hollow member, a laser beam is irradiated to this edge part, and the said flange part is formed. Mounting method of hollow member and fastening member.   The hollow member according to any one of claims 1 to 3, further comprising a fourth step of separating the flange portion of the fastening member and a part of the inner peripheral surface of the hollow member to solidify the flange portion. Attachment method of a fastening member.   The method for attaching the hollow member and the fastening member according to claim 4, further comprising a fifth step of engaging the solidified flange portion with the other portion of the inner peripheral surface of the hollow member.   The hollow member and the fastening member according to any one of claims 1 to 5, wherein the hollow member is divided into a plurality of cells by at least one partition wall, and the insertion hole is provided in at least one of the cells. Mounting method.   The method for attaching the hollow member and the fastening member according to any one of claims 1 to 6, wherein a difference in solubility parameter between the insertion portion of the hollow member and the fastening member is 1.0 or more. A mounting structure of a hollow member and a fastening member,
The hollow member has an insertion hole and is made of a transmissive material that transmits laser light, and the fastening member has an insertion portion, and at least the insertion portion is an absorptive material that absorbs laser light and is heated. Composed of plastic material,
At least a part of the insertion portion of the fastening member is accommodated in the hollow member through an insertion hole of the hollow member;
The insertion hole formed by pressing the end of the insertion part accommodated in the hollow member by laser light irradiation from the outside of the hollow member and pressing a part of the inner peripheral surface of the hollow member A mounting structure of a hollow member and a fastening member having a relatively larger flange portion.

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