WO2023074659A1

WO2023074659A1 - Bonding joint for bonding to resin, bonding joint manufacturing method, and metal-resin bonding structure

Info

Publication number: WO2023074659A1
Application number: PCT/JP2022/039634
Authority: WO
Inventors: 達也鈴木; 健裕小池
Original assignee: 中央可鍛工業株式会社
Priority date: 2021-10-28
Filing date: 2022-10-25
Publication date: 2023-05-04
Also published as: JP2023066298A; JP7414787B2; CN118076450A

Abstract

The present invention provides a metal-resin bonding structure having increased bonding strength. A bonding joint 1 is formed in a drum shape having a groove-shaped recessed section 13 that is formed in the circumferential direction of a substantially cylindrical metal side surface 11a, and a curved section 14 that curves between two bottom surfaces 12. The recessed section 13 and upper and lower end sections 15 of the side surface 11 form a coarse relief shape 101, and the side surface 11 including the recessed section 13 serves as a bonding surface 10. A fine relief shape 100 having an arithmetic mean roughness Ra of 10-300 μm is formed on the bonding surface 10. By forming the coarse relief shape 101 and the fine relief shape 100 on the bonding surface 10, the bonding joint 1 strongly bonds with a resin.

Description

JOINT JOINT TO BE JOINTED WITH RESIN, METHOD FOR MANUFACTURING JOINT JOINT, AND JOINT STRUCTURE BETWEEN METAL AND RESIN

The technical field of this specification relates to a joint structure between metal and resin.

Conventionally, the joint structure of metal and resin has been known. In the joint structure of metal and resin disclosed in Patent Document 1, knurling is applied to the surface of the metal, and the resin is joined to the jagged edges of the knurling. Further, in the bearing device as a joint structure of metal and resin disclosed in Patent Document 2, the bearing portion and the bolt hole forming portion are made of metal, and the bracket connecting the bearing portion and the bolt hole forming portion is made of resin. . As a result, the weight of the bearing device is reduced. Patent Document 2 is a patent application filed by the applicant of the present application.

JP 2018-115679 A Japanese Patent Application Laid-Open No. 2020-012502

　In the conventional metal-resin bonding structures described in these patent documents, there is a demand to increase the bonding strength between the metal and the resin.

The problem to be solved by the technology of the present specification was made in view of the above points, and aims to provide a joint structure of metal and resin with increased joint strength.

A joint joint to be joined to a resin according to an embodiment of the present specification is formed of a metal, has a joint surface to be joined to a resin on its surface, has a fine uneven shape formed on the joint surface, and has an arithmetic shape of the fine uneven shape. It is characterized by having an average roughness Ra of 10 to 300 μm.

According to the joint to be joined to resin according to the embodiment of the present specification, the area where the joint surface and the resin are in contact can be increased, and the resin that enters the fine irregularities of the joint surface has an effect as an anchor. Therefore, the bonding strength between the metal and the resin can be increased.

Here, in the joint joint, a groove-shaped concave portion may be formed in the joint surface.

According to this, the groove-shaped recess forms a rough uneven shape on the bonding surface, and the resin enters the rough uneven shape, so that the bonding strength between the metal and the resin can be increased.

Further, in the above joint, the joint surface may be a substantially cylindrical shape with a side surface, and the concave portion may be formed in the circumferential direction of the side surface.

According to this, resin can be joined to the substantially cylindrical joining joint over the circumferential direction of the side surface.

Further, in the joint joint described above, the constricted portion formed in the circumferential direction by the recess may have a radial cross-section that is substantially polygonal.

According to this, since the constricted portion formed by the concave portion and the resin entering the concave portion are fitted in a substantially polygonal shape, the joint strength between the metal and the resin is increased against the rotation of the joint in the circumferential direction. can be enhanced.

Here, a method for manufacturing a bonded joint according to an embodiment of the present specification is a method for manufacturing a bonded joint described above,
By forming the mold for casting the joint joint from coarse aggregate, a fine uneven shape is formed on the surface of the mold,
It is characterized in that fine irregularities are formed on the surface of the bonded joint cast from the mold.

According to the method for manufacturing a bonded joint according to the embodiment of the present specification, it is possible to form a mold having fine irregularities on the surface due to the grain size of the coarse aggregate, so that the fine irregularities can be formed at low cost. can.

Further, in the method for manufacturing a bonded joint described above, the average particle diameter (median diameter d50) of the aggregate may be 200 to 2000 μm.

According to this, it is possible to form a fine irregular shape on the joint surface to increase the joint strength with the resin.

Here, the metal-resin joint structure according to the embodiment of the present specification includes the above joint joint,
a resin bracket covering the joint surface of the joint and fixing the joint, the base being made of a resin;
characterized by having

According to the joint structure of metal and resin according to the embodiment of the present specification, the joining joint and the resin bracket can be firmly joined.

According to the joint according to the embodiment of the present specification, the joint strength between metal and resin can be enhanced.

1 is a perspective view of an embodiment bonding joint; FIG. It is a front view of the joint joint. 3 is a cross-sectional view taken along line III-III of FIG. 2; FIG. FIG. 3 is a cross-sectional view of a mold for casting the joint joint; FIG. 11 is a perspective view of a joint structure using the same joint joint; FIG. 3 is a front view of a bearing device using the joint joint; It is a top view of the same bearing device.

Hereafter, joints to be joined to resin according to embodiments of the present specification will be described based on the drawings. However, the technology of this specification is not limited to these embodiments. The joint 1 of the embodiment is used as an insert member (insert collar, insert nut), and as shown in FIG. , and has a hourglass shape with a constricted portion 14 between both bottom surfaces 12 . The upper and lower ends 15 of the side surface 11 and the recessed portions 13 form a rough uneven shape 101, and the side surface 11 including the recessed portions 13 becomes the joint surface 10 with the resin. The joint surface 10 is formed with a fine uneven shape 100 having an arithmetic mean roughness Ra of 10 to 300 μm. By forming the coarse irregularities 101 and the fine irregularities 100 on the joint surface 10, the joint 1 can strengthen the joint with the resin. In addition, as shown in FIGS. 6 and 7, the joint 1 of the embodiment includes the shaft bearing portion 201 and the bolt hole forming portion (the joint 1 ) is made of metal, and the bracket (resin bracket 2) connecting the shaft bearing portion 201 and the bolt hole formation portion is made of resin. As a result, the weight of the bearing device as a joint structure of metal and resin can be reduced. In this specification, as shown in FIG. 1, the orientation of the joint 1 is defined as the direction of the axis that connects the centers of the bottom surfaces 12, and U is up and D is down. show. In addition, the axis connecting the centers of both bottom surfaces 12 may be expressed as a radial direction and a circumferential direction.

The joining joint 1 is made of metal, and as the metal, specifically, spheroidal graphite cast iron product FCD500 (JIS G 5502:2007) is used. The spheroidal graphite cast iron product has excellent tensile strength and heat resistance, and is excellent in durability as the joint 1 . Also, as another embodiment, 12 types of aluminum alloy die casting ADC12 (JIS H 5302:2006) was used. The ADC 12 is excellent in mechanical properties, machinability and castability. The joining joint 1, which will be described later in detail, was manufactured by casting using a mold, which can be manufactured at a low cost and is suitable for mass production.

As shown in FIGS. 1 to 3, the joining joint 1 of the embodiment has a single groove-shaped concave portion 13 formed along the circumference of a substantially cylindrical side surface 11, and the upper and lower ends of each groove. 15, 15 are thick, and the constricted portion 14 in the center in the vertical direction is constricted to form a drum shape. The joining joint 1 has a rough uneven shape 101 formed by upper and

lower ends

15 and 15 and a constricted portion 14 in the center in the vertical direction. Due to the rough uneven shape 101, when the joining joint 1 is fixed to the resin bracket 2 as shown in FIG.

As shown in FIG. 2, the outer circumferential corner forming the concave portion 13 is formed with a chamfered portion 13a that is rounded inwardly, and the inner circumferential corner is roundedly chamfered outwardly as a chamfered portion 13b. is formed. When the joining joint 1 is fixed to the resin bracket 2, the stress applied to the resin can be dispersed by the chamfered

portions

13a and 13b.

As shown in FIG. 3, the constricted portion 14 has a substantially rectangular cross section in the radial direction. Since the cross section of the constricted portion 14 is substantially square, when the joint 1 is fixed to the resin bracket 2, the constricted portion 14 formed by the recess 13 and the resin entering the recess 13 are substantially square. Because of the fitting, the bonding strength between the metal and the resin can be increased against the rotation of the bonding joint in the circumferential direction. A chamfered portion 14a that is rounded inward is formed at a vertical outward corner portion that forms a substantially rectangular shape of the constricted portion 14. As shown in FIG. When the joint 1 is fixed to the resin bracket 2, the stress applied to the resin can be dispersed by the chamfered portion 14a.

The upper and lower bottom surfaces 12 of the joining joint 1 are circular, and a screw hole 16 is passed through the center on the vertical axis. Through the screw holes 16, the joint joint 1 can be joined to other members by means of screws or the like. The screw hole 16 may be a circular hole without threads or a non-threaded hole such as a polygonal hole.

The side surface 11 including the concave portion 13 of the joint 1 of the embodiment serves as the joint surface 10 that joins with the resin of the resin bracket 2 . The bonding surface 10 is formed with a fine uneven shape 100 having an arithmetic mean roughness Ra of about 90 μm. Since fine irregularities 100 with an arithmetic mean roughness Ra of about 90 μm are formed on the joint surface 10, when the joint 1 is joined to the resin of the resin bracket 2, the resin enters the fine irregularities 100 and the anchor As a result, the bond between the joint 1 and the resin can be strengthened.

The fine irregularities 100 with an arithmetic mean roughness Ra of about 90 μm are formed by forming the mold 3 for casting the joint 1 from coarse aggregates 32 ( FIG. 4 ), which will be described later in detail, so that the surface of the mold 3 A fine uneven shape 100 is formed on the mold 3 , and the fine uneven shape 100 is transferred to the side surface 11 of the joint 1 cast from the mold 3 .

Next, a method for manufacturing the joint 1 of the embodiment will be described. The welded joint 1 is manufactured by casting using a mold 3, and in the method for manufacturing the welded joint 1 of the embodiment, the method for manufacturing the mold 3 for casting the welded joint 1 and the method for manufacturing the welded joint 1 using the mold 3 will be described separately. do.

The method of manufacturing the mold 3 includes a primary mold creation step of creating a primary mold by replicating the master model (3D data) from the master model (3D data) of the joint 1, and a fine uneven shape on the surface using coarse aggregate 32 from the primary mold. and a mold making step for making a secondary mold (mold 3) having 100.

In the primary mold creation process, a primary mold made of metal (or resin) was created by duplicating the master model of the joint 1 from the master model using a general-purpose method.

In the mold making process, as shown in FIG. 4, the mold 3 (secondary mold) was formed by injecting a molding agent for forming a gas-hardening sand mold so as to mold the primary mold. The molding agent for forming the gas-curable sand mold was hardened using a cold box method, which is a type of gas-hardening molding method in which gas is passed through the molding agent to harden it, and the mold 3 was molded.

The molding agent is prepared by mixing the aggregate 32, the resin and the curing agent. (JIS G 5901:2016) was used, and the resin and curing agent used were general-purpose resins and curing agents used in the cold box method. The molding agent contained 98.4% aggregate 32, 0.8% resin, and 0.8% curing agent. Since the molding agent is formed from roughly coarse aggregates 32, the mold 3 formed from the molding agent has a fine uneven shape 100 whose surface shape is the shape (grain size) of the aggregates 32. .

The manufacturing method of the welded joint 1 using the mold 3 consists of a pouring step of pouring molten metal into the mold 3 and an unframing step of removing the welded joint 1 by breaking the frame.

In the pouring process, molten metal is poured into the mold 3, cooled and solidified to form the joint 1. Pouring is performed by a general-purpose method.

In the unframing step, the bonded joint 1 is unframed from the mold 3, unnecessary materials such as burrs are removed, and the bottom surface 12 is machined to eliminate the fine irregularities 100 of the bottom surface 12, so that the bonded joint 1 can be used. It was assumed that it was possible.

The bonded joint 1 manufactured in this manner has a fine uneven shape 100 formed on the bonding surface 10 of the side surface 11 . Further, a rough concave-convex shape 101 is formed by the upper and

lower end portions

15 , 15 of the circumferential groove-shaped concave portion 13 of the side surface 11 of the joint 1 and the central constricted portion 14 in the vertical direction. The joint 1 can adjust the size of the fine concave-convex shape 100 only by changing the size of the aggregate 32 forming the mold 3 .

Next, a joint structure of metal and resin using the joint 1 of the embodiment will be described. In the embodiments, a joint structure in which a joint 1 is used in a bolt hole forming portion that is joined to a vehicle body will be described as an example of a bearing device that rotatably supports a shaft of a vehicle.

As shown in FIGS. 6 and 7, the bearing device 200 includes an annular shaft bearing portion 201 through which a shaft is inserted via a bearing, and a joint joint into which bolts are inserted to fix the shaft bearing portion 201 to a fixed portion. 1 and a bracket that connects the shaft bearing portion 201 and the joint 1, the shaft bearing portion 201 and the joint 1 are made of metal, and the bracket (resin A bracket 2) is made of resin. As a result, the weight of the bearing device 200 is reduced.

The resin bracket 2 integrally connects the shaft bearing portion 201 and the joining joint 1, is made of a resin mixture, and is molded by a molding die. Two resins were used separately for the resins used in the resin mixture. One of the resins used was a polyamide resin that is a thermoplastic resin, and the other resin was a phenolic resin that is a thermosetting resin. By using a polyamide resin or a phenol resin as the resin used in the resin mixture, the resin bracket 2 can be made excellent in heat resistance and mechanical strength.

The resin mixture used for the resin bracket 2 was mixed with glass fibers as fibers to form a fiber mixed resin. Mixing fibers into the resin mixture can reduce curing shrinkage of the resin and increase physical strength. The mixing ratio of the fibers in the fiber mixed resin was set to 40% by mass in order to efficiently increase the physical strength.

The joining joint 1 used in the bearing device 200 has the fine concave-convex shape 100 formed on the joint surface 10 of the side surface 11 including the concave portion 13, so that the joint between the resin bracket 2 and the resin can be strengthened. . Further, as shown in FIG. 5, the joint 1 has a rough irregular shape 101 formed by the upper and lower ends 15, 15 and the concave portion 13 in the center in the vertical direction. On the other hand, the anti-disengagement effect is enhanced, and since the cross section in the radial direction of the constricted portion 14 is substantially square, the anti-rotation effect is enhanced.

It should be noted that the joining joint 1 of the embodiment and the connection structure of metal and resin can be implemented even if the configuration is changed to the following forms.

In the joint 1 of the embodiment, as the iron alloy (cast iron) used for forming the joint 1, the spheroidal graphite cast iron FCD500 was used, but the spheroidal graphite cast iron products (FCD350, FCD400 , FCD450, FCD600, FCD700, FCD800) can be used. This is because it has excellent mechanical strength.

In the bonded joint 1 of the embodiment, ADC12 was used as the aluminum alloy die casting used to form the bonded joint 1, but aluminum alloy die castings (ADC1, ADC3, ADC5, ADC6, ADC10, ADC10Z, ADC12Z, ADC14) can be used.

In the joint 1 of the embodiment, the radial cross section of the constricted portion 14 is substantially square, but the radial cross section of the constricted portion 14 may be substantially triangular to substantially hexagonal. This is because the effect of preventing the resin bracket 2 from coming off and the effect of preventing rotation can be enhanced. The radial cross-section of the constricted portion 14 can also be circular.

In the joint 1 of the embodiment, one groove-shaped concave portion 13 is provided over the circumferential direction of the side surface 11, but one to three groove-shaped concave portions 13 can be provided in the vertical direction. . This is because the effect of preventing the resin bracket 2 from coming off can be enhanced. Note that if the number exceeds three, the structure of the joint 1 may become complicated. As another embodiment, one or two groove-shaped recesses 13 can be provided in the vertical direction.

Although the joining joint 1 of the embodiment is a substantially cylindrical insert member (insert collar, insert nut), it is not limited to the insert member, and can be used as long as it is used for joining metal and resin. . Moreover, the shape is not limited to a substantially cylindrical shape, and may be, for example, a conical shape, a prismatic shape, a pyramidal shape, or the like.

In the method of manufacturing the joint 1 of the embodiment, the mold 3 is formed by a gas-hardening sand mold, but the mold 3 can also be formed by a green sand mold, a self-hardening sand mold, a thermosetting sand mold, or the like.

In the method for manufacturing the joint 1 of the embodiment, the aggregate 32 mixed with the molding agent for forming the gas-hardening sand mold serving as the mold 3 is used for the mold with the sieve having the largest aggregate mass and having a nominal opening of 1180 μm. Silica sand No. 3 (average particle size (median size d50): 1500 μm) was used, but aggregates 32 with an average particle size of 200 to 2000 μm can be used. This is because it is possible to form the fine unevenness 100 that strengthens the bonding with the resin. If the average particle diameter of the aggregate is less than 200 μm, the fine irregularities 100 become finer, and there is a possibility that the bonding with the resin cannot be strengthened. On the other hand, if it exceeds 2000 μm, the strength of the mold 3 may deteriorate. As another embodiment, the average particle size of aggregate 32 can be between 600 and 1700 μm.

In the method for manufacturing the joint 1 of the embodiment, the aggregate 32 mixed with the molding agent for forming the gas-hardening sand mold serving as the mold 3 is used for the mold with the sieve having the largest aggregate mass and having a nominal opening of 1180 μm. Silica sand No. 3 was used, but any size of silica sand from No. 6 to No. 3 can be used. In another embodiment, the size of the silica can be No. 4 to No. 3 foundry silica. Further, as the aggregate 32, calcium carbonate powder, selvene (pulverized sanitary ware), crushed stone powder, etc. can be used as long as they have the same average particle size.

In the method for manufacturing the joint 1 of the embodiment, the molding agent for forming the gas-hardening sand mold that serves as the mold 3 contains 98.4% aggregate 32, 0.8% resin, and 0.8% curing agent. However, any molding agent containing 70 to 99% aggregate 32, 0.5 to 15% resin, and 0.5 to 15% curing agent can be used. can. In another embodiment, the molding compound may contain 90-99% aggregate 32, 0.5-5% resin, and 0.5-5% hardener.

Polyamide resin is used as the thermoplastic resin of the resin mixture forming the resin bracket 2 in the embodiment, but thermoplastic resins such as polypropylene, polyvinyl chloride, polystyrene, acrylic resin, polycarbonate resin, and ABS resin having excellent heat resistance can be used. Resin can be used.

As the thermosetting resin of the resin mixture forming the resin bracket 2, phenolic resin is used in the embodiment, but thermosetting resin such as amino resin and urea resin can also be used. It is because it is excellent in heat resistance.

In the embodiment, glass fibers, which are inorganic fibers, are used as fibers of the fiber-mixed resin, which is a resin mixture forming the resin bracket 2. However, inorganic fibers such as carbon fibers, metal fibers, and ceramic fibers, cellulose fibers, and acrylic fibers are also used. , polyamide fibers, polyester fibers and the like can also be used.

Although the mixing ratio of fibers in the fiber mixed resin is 40% by mass in the embodiment, it can be used as long as it is 10 to 70% by mass. If the mixing ratio is less than 10% by mass, the strength may not be sufficiently increased. On the other hand, if it exceeds 70% by mass, the density of the fiber-mixed resin increases, and there is a risk that the weight of the bearing device 200 cannot be reduced. It is more preferably 20 to 60% by mass, still more preferably 30 to 50% by mass.

In the embodiment, the fiber-mixed resin is a polyamide resin or a phenolic resin mixed with 40% by mass of glass fiber, but a commercially available product can also be used. Commercially available glass fiber mixed resins include A1022GFL15, A1022GFL, A1030GFL, A1030GFL45, A1022GFL60 (A), EX-8406G30, A175S, A190S, A192S, A690S (manufactured by Unitika Ltd.), CM1011G-15, CM1001. G-15, CM1001G-20, CM1011G-30, CM1016G-30, CM1011G-45, CM1012G-45N, CM3001G-15, CM3006G-15, CM3001G-30, CM3006G-30, CM3001G-45, CM3006G-45 (manufactured by Toray Industries, Inc.) ) can be used.

DESCRIPTION OF SYMBOLS 1... Joint joint 2... Resin bracket 3... Mold 3a... Side part 10... Joint surface 11... Side surface 12... Bottom surface 13... Recessed part 13a... Chamfered part 13b... Chamfered part 14... Constricted part , 14a... Chamfered portion 15... End portion 16... Screw hole 32... Aggregate 100... Fine uneven shape 101... Rough uneven shape 200... Bearing device 201... Shaft bearing portion.

Claims

A joint characterized by being formed of a metal, having a bonding surface to be bonded to a resin on the surface, forming a fine uneven shape on the bonding surface, and having an arithmetic mean roughness Ra of 10 to 300 μm of the fine uneven shape fittings.
The joining joint according to claim 1, characterized in that a groove-shaped concave portion is formed in the joining surface.
The joining joint according to claim 2, characterized in that the joint surface has a substantially cylindrical shape that serves as a side surface, and the concave portion is formed in the circumferential direction of the side surface.
The joining joint according to claim 3, characterized in that the radial cross-section of the constriction formed in the circumferential direction by the recess is substantially polygonal.
A method for manufacturing a bonded joint according to claim 1,
By forming the mold for casting the joint joint from coarse aggregate, a fine uneven shape is formed on the surface of the mold,
A method for manufacturing a bonded joint, characterized in that fine irregularities are formed on the surface of the bonded joint cast from the mold.
The method for producing a welded joint according to claim 5, wherein the aggregate has an average particle size (median size d50) of 200 to 2000 µm.
a joint joint according to claim 1;
a resin bracket covering the joint surface of the joint and fixing the joint, the base being made of a resin;
A joint structure of metal and resin, characterized by having