JP2019188653A - Manufacturing method of joined body and joined body manufactured by manufacturing method - Google Patents

Abstract

To provide a manufacturing method of a joined body having a high degree of freedom in design and capable of producing a joined body at low cost, and a joined body manufactured by the manufacturing method.SOLUTION: A manufacturing method of a joined body 9 for producing the joined body 9 of a resin part 10 and a metal part 20 includes a preparation process for preparing a resin part 10 made of a thermoplastic resin having a fitted part 11 and a metal part 20 having a fitting part 21 that can be fitted to the fitted part 11, a fitting process for fitting the fitting part 21 to the fitted part 11, and a welding process to melt and weld the fitted part 11 and the fitting part 21 by melting a fitted surface of the fitted part 11 while appling a pressure to the fitted part 11 or the fitting part 21 by an external heating device 30, with the fitted part 11 and the fitting part 21 being fitted to each other.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for manufacturing a bonded body and a bonded body manufactured by the manufacturing method.

The steering device includes a cylindrical exterior part that opens in the left-right direction, and accommodates a steered shaft in the exterior part. With respect to such exterior parts, metal housings are conventionally used to ensure rigidity or protect built-in parts.
On the other hand, in recent years, in order to reduce the weight, it has been studied to form a part of an exterior part with a resin material, in other words, to use a resin part. For example, the following patent document proposes a resin pipe in which metal parts are integrated (joined) by insert molding.

JP 2015-145100 A

  However, according to insert molding, it is necessary to ensure the direction in which the mold is removed. Therefore, there is a problem that the shape of a molded product (a joined body obtained by joining a resin part and a metal part) is greatly limited, and the degree of freedom in design is low. In addition, it is necessary to manufacture a mold for insert molding, which increases the manufacturing cost. Under such circumstances, it is desired that a method for manufacturing a joined body obtained by joining a resin part and a metal part can be manufactured at a low cost with a high degree of design freedom.

  The present invention was created in order to solve such problems, and has a high degree of freedom in design and can be manufactured at a low cost, and a bonded body manufactured by the manufacturing method. The purpose is to provide a body.

  In order to solve the above problems, a method for manufacturing a joined body according to the present invention is a method for producing a joined body for producing a joined body of a resin part and a metal part, and is made of a thermoplastic resin having a fitted portion. A resin component and a preparation step of preparing the metal component having a fitting portion that can be fitted into the fitting portion; a fitting step of fitting the fitting portion into the fitting portion; In a state where the fitting portion and the fitting portion are fitted, the fitting surface of the fitted portion is melted while applying pressure to the fitted portion or the fitting portion by an external heating device, A welding step of welding the fitted portion and the fitting portion.

  According to the present invention, since it is not necessary to consider the direction in which the mold is pulled out, the degree of freedom in design is high. Moreover, a mold for insert molding becomes unnecessary, and the joined body can be manufactured at low cost.

It is a schematic part for demonstrating the steering device provided with exterior components. It is a flowchart for demonstrating the manufacturing method in 1st Embodiment. It is the schematic which shows the welding process of 1st Embodiment. It is the schematic which shows the welding process of 2nd Embodiment. It is the schematic which shows the welding process of a 1st modification. It is the schematic which shows the welding process of a 2nd modification.

  First, the steering apparatus 1 including the exterior component 9 that is a joined body will be described, and then the manufacturing method of the embodiment of the present invention will be described.

(Steering device)
As shown in FIG. 1, the steering device 1 includes a steering wheel 2 that is operated by a driver, a steering shaft 3 that rotates integrally with the steering wheel 2, a torsion bar 4 that is coupled to the lower end of the steering shaft 3, and a torsion A pinion shaft 5 connected to the lower end of the bar 4 and having a pinion 5a at the lower end, a rack shaft (steering shaft) 6 having a rack 6a meshing with the pinion 5a, and a rack end 7 fixed to both ends of the rack shaft 6 , 7 and rack end studs 8, 8, and an exterior component 9 that houses the rack shaft 6.
Further, steering wheels (not shown) are connected to the rack end studs 8, 8, and when the driver rotates the steering wheel 2, the rack shaft 6 moves to the left or right to steer the steering wheels. Can do.

  The exterior part 9 is a joined body obtained by joining a resin part and a metal part, and includes a rack cover 10 that is a cylindrical resin pipe, and metal left and right housings 20 and 20 that are joined to both ends of the rack cover 10. . Of the left and right housings 20, 20, the left housing 20 is a part for protecting the end of the rack cover 10, and the right housing 20 accommodates the meshing portion between the pinion 5 a and the rack 6 a. It is a part for protection. Hereinafter, a method for manufacturing the exterior component 9 will be described.

(First embodiment)
As shown in FIG. 2, the manufacturing method of the exterior component (joined body) 9 includes a preparation process, a fitting process, and a welding process.

(Preparation process)
The preparation step is a step of preparing the rack cover 10 having the fitted portion 11 and the left and right housings 20 and 20 having the fitting portion 21 that can be fitted to the fitted portion 11.

The rack cover 10 in this embodiment is manufactured by injection molding in which a molten resin is injected into a mold and molded into a cylindrical shape. The resin used for manufacturing the rack cover 10 is a thermoplastic resin that can be melted at a predetermined temperature. Examples of the thermoplastic resin include thermoplastic resins such as polyethylene (PE), polypropylene (PP), polyphenylene sulfide (PPS), and polyether ketone (PEEK), but are not particularly limited in the present invention.
Alternatively, from the viewpoint of improving the strength, the rack cover 10 may be manufactured by pressing a fiber-reinforced resin sheet containing fibers in the above-described thermoplastic resin with a mold.

After the rack cover 10 is manufactured, the fitted portion 11 is formed on the rack cover 10. The formation method of the to-be-fitted part 11 is not specifically limited. For example, the fitted portion 11 may be formed when the rack cover 10 is manufactured, or the fitted portion 11 may be formed by stepping the outer peripheral surface of the rack cover 10. In the present embodiment, both end portions of the rack cover 10 at the time of manufacture constitute the fitted portion 11 as it is, and no special processing is performed.
Moreover, after forming the to-be-fitted part 11, in order to make it easy to insert the to-be-fitted part 11 in the fitting part 21 at a fitting process, it is preferable to chamfer the edge part of the to-be-fitted part 11. FIG.

Examples of the manufacturing method of the left and right housings 20 and 20 include casting, forging, cutting, or pressing. Moreover, the fitting part 21 may be formed in the manufacturing stage of the left and right housings 20 and 20, or may be formed by cutting after the manufacturing of the left and right housings 20 and 20.
The fitting part 21 is formed in a cylindrical shape, and the inner diameter is slightly smaller than the outer diameter of the fitted part 11 of the rack cover 10, and the tightening margin is secured.

  After preparing the rack cover 10 having the fitted portion 11 and the left and right housings 20, 20 having the fitting portion 21, it is preferable to perform a washing / drying step of washing and drying these. According to the said process, the foreign material etc. which adhere to the to-be-fitted part 11 and the fitting part 21 are removed, and the welding strength of the to-be-fitted part 11 and the fitting part 21 can be raised in a subsequent welding process.

(Mating process)
The fitting step is a step of press-fitting the fitted portion 11 of the rack cover 10 into the fitting portion 21 of the housing 20 and fitting the fitted portion 11 into the fitting portion 21. In this step, a jig for fixing the rack cover 10 or a jig for pushing the housing 20 may be used, and the press-fitting method is not particularly limited.

(Welding process)
In the welding process, the outer periphery of the fitted portion 11 of the rack cover 10 is applied with pressure applied to the fitted portion 21 of the housing 20 by an external heating device in a state where the fitted portion 11 and the fitted portion 21 are fitted. This is a step of melting the surface (surface to be fitted) and welding the portion to be fitted 11 and the fitting portion 21.
The method for welding the rack cover 10 and the left housing 20 is the same as the method for welding the rack cover 10 and the right housing 20. Therefore, in the following description, a method of welding the rack cover 10 and the left housing 20 will be described, and a description of a method of welding the rack cover 10 and the right housing 20 will be omitted.

The external heating device is a device that can be melted without contacting the portion to be melted (the outer peripheral surface of the fitted portion 11). In the first embodiment, an ultrasonic welder is used as the external heating device.
The ultrasonic welding machine is one of frictional heat welding devices that generate frictional heat at the contact surface between the fitted portion 11 and the fitting portion 21 to melt the resin. Specifically, electrical energy is mechanically transmitted. This is a device that converts the vibration energy into mechanical energy through the horn 30 to the component and generates frictional heat at the contact surface between the components. In addition, the ultrasonic welder has a pressurizing function for pressurizing a component that contacts the horn 30 in addition to the vibration function.

  In the welding process of the first embodiment using an ultrasonic welding machine, as shown in FIG. 3, the rack cover 10 is first attached to the fixing jig 40 and the rack cover 10 is fixed. Note that the fixing jig 40 includes a support column 42 erected on the fixing table 41 and a pair of clamping units 43 and 43 that clamp the rack cover 10 from above and below the support column 42.

Next, the horn 30 of the ultrasonic welder is brought into contact with the outer peripheral surface of the fitting portion 21 of the housing 20. In the present embodiment, the upper portion 21 a located on the upper side of the outer peripheral surface of the fitting portion 21 is in contact.
Next, the ultrasonic welding machine is activated. Accordingly, the horn 30 exerts a pressing force (see an arrow in FIG. 3) that presses the upper portion 21 a of the fitting portion 21 downward, and the horn 30 is perpendicular to the upper portion 21 a of the fitting portion 21 (up and down direction). ) Vibrate.
As a result, the vibration of the horn 30 is transmitted to the fitting part 21, and frictional heat is generated at the interface between the upper surface 21b on the inner peripheral side of the fitting part 21 and the upper surface 11a on the outer peripheral side of the fitted part 11 opposite thereto. Will occur. And when frictional heat exceeds predetermined temperature, the upper surface 11a of the to-be-fitted part 11 will fuse | melt.
After the upper surface 11a of the fitted portion 11 is melted, the position where the horn 30 is applied is moved in the circumferential direction. Thereby, the molten resin is solidified, and the upper surface 21b of the fitting part 21 and the upper surface 11a of the fitted part 11 are welded.

  In this way, the position where the horn 30 is applied is moved in the circumferential direction with respect to the outer peripheral surface of the fitting portion 21 to weld the entire circumference of the fitted portion 11 and the fitting portion 21. And if the perimeter of the to-be-fitted part 11 and the fitting part 21 welds, the exterior component 9 (joined body) will be completed.

  As mentioned above, according to the manufacturing method of 1st Embodiment mentioned above, it is not necessary to consider the direction which removes a metal mold | die. Therefore, restrictions on the design of the joined body are reduced, and the degree of freedom in design is increased. Moreover, a die for insert molding is not necessary, and the bonded body can be made inexpensive.

  In the first embodiment, the horn 30 of the ultrasonic welder is used to contact the outer peripheral surface of the fitting portion 21 and press the fitting portion 21 radially inward. 30 may be disposed in the fitted part 11 and used so as to press the fitted part 11 radially outward by contacting the inner peripheral surface of the fitted part 11. However, when using it so that the inner peripheral surface of the to-be-fitted part 11 may be pressed, it is necessary to fix with the fixing jig 40 etc. so that the fitting part 21 may not move.

In the first embodiment, an example in which an ultrasonic welding device that vibrates in a direction perpendicular to the outer peripheral surface of the fitting portion 21 is used as the frictional heat welding device. An ultrasonic welding apparatus that generates frictional heat by vibrating in the surface direction may be used. Further, as long as the frictional heat can be generated by vibration, the ultrasonic wave (ultrasonic welding apparatus) may not be used.
The external heating device of the present invention is not limited to a frictional heat welding device (ultrasonic welding device). Hereinafter, an example using another external heating device will be described.

(Second Embodiment)
The manufacturing method of the exterior component 9 of the second embodiment includes a preparation step, a fitting step, and a welding step. In addition, since the preparation process and fitting process of 2nd Embodiment are the same as the preparation process and fitting process of 1st Embodiment, description is abbreviate | omitted.

(Welding process)
In the welding process of the second embodiment, the external heating device includes a pressurizing device 50 for applying pressure to the fitted portion 11 or the fitting portion 21 and a high-frequency induction device for causing the fitting portion 21 to generate heat. And.
As shown in FIG. 4, the high-frequency induction device includes an annular coil portion 60, and a fitting portion 21 that is a metal part is disposed in the coil portion 60, and an eddy current is generated in the fitting portion 21 by electromagnetic induction. This is a device that causes the fitting portion 21 to generate heat.

The pressurizing device 50 presses a part of the outer peripheral surface of the fitting part 21 radially inward and presses a part of the inner peripheral surface of the fitting part 21 to a part of the outer peripheral surface of the fitted part 11. It is a device for.
The pressurizing device 50 of the present embodiment includes an electric motor (not shown) having a rotating shaft 51, an L-shaped L-shaped arm 52 connected to the rotating shaft 51, and a pressurizing unit that is rotatably attached to the L-shaped arm 52. And a roller 53.
Further, the distance L1 from the rotation axis O1 of the rotation shaft 51 to the inner surface of the pressure roller 53 is set to be smaller than the outer diameter of the fitting portion 21. Therefore, when the rotary shaft 51 is disposed coaxially with the rack cover 10 and the pressure roller 53 is disposed so as to contact the outer peripheral surface of the fitting portion 21, the pressure roller 53 is caused by the elastic deformation force of the L-shaped arm 52. Presses the outer peripheral surface of the fitting portion 21 radially inward. Note that the portion pressed by the pressure roller 53 can be changed by the rotation of the rotating shaft 51.

In the welding process of the second embodiment using the high frequency induction device and the pressurizing device 50, as shown in FIG. 4, the rack cover 10 is first attached to the fixing jig 40, and the rack cover 10 is fixed.
Next, the rotary shaft 51 of the electric motor of the pressure device 50 is arranged coaxially with the rack cover 10, and the pressure roller 53 is placed on the outer peripheral surface of the fitting portion 21 of the housing 20 while bending the L-shaped arm 52. Make contact. In the present embodiment, the pressure roller 53 is in contact with the upper portion 21a located on the upper side of the outer peripheral surface of the fitting portion 21, and presses the upper portion 21a radially inward (lower side) (see FIG. (See arrow 4).
Next, the fitting part 21 is arrange | positioned in the coil part 60 of a high frequency induction device, and it starts. Thereby, the fitting part 21 generates heat by electromagnetic induction. In addition, the part which generate | occur | produces heat is not a part of fitting part 21, but the perimeter.
According to this, the upper surface 11a of the fitted portion 11 pressed against the fitting portion 21 that generates heat is melted. Next, when the rotating shaft 51 is rotated to change the portion pressed by the pressure roller 53, the melted resin on the upper surface 11a of the fitted portion 11 is solidified, and the upper surface 21b on the inner peripheral side of the fitting portion 21 The upper surface 11a of the fitted portion 11 is welded.

  Then, the position where the pressure roller 53 abuts against the outer peripheral surface of the fitting portion 21 is moved in the circumferential direction, and the entire circumference of the fitted portion 11 and the fitting portion 21 is welded. When the entire periphery of the fitting part 21 is welded, the exterior component 9 (joined body) is completed.

In the present invention, the metal material of the housing 20 heated by the high frequency induction device is not particularly limited as long as it can be heated by electromagnetic induction.
Here, from the viewpoint of improving the strength and shortening the heating time by electromagnetic induction, as a material for forming the housing 20, carbon steel materials for mechanical structures (JIS G4051: S10C and S35C defined in 2016), automobile structures Hot-rolled steel sheets and steel strips (JIS G3113: SAPH defined in 2006), hot-rolled mild steel sheets and steel bands (JIS G3131: SPHC defined in 2010), cold-rolled steel sheets and steel A belt (such as SPCC defined in JIS G3141: 2017) is preferred.
Alternatively, from the viewpoint of improving the strength, plates and strips of aluminum and aluminum alloy (such as 3000 series or 5000 series defined in JIS H4000: 2014), aluminum alloy die casting (ADC12 defined in JIS H5302: 2006). Etc.).

  Further, the pressure device used in the present invention is not limited to the pressure device 50 used in the second embodiment. For example, a pressure device in which a pressure roller is disposed inside the fitted portion 11 and presses a part of the inner peripheral surface of the fitted portion 11 may be used. Next, a manufacturing method that can further increase the adhesion strength between the rack cover 10 and the left and right housings 20 and 20 will be described.

(Third embodiment)
The manufacturing method of the exterior component 9 according to the third embodiment includes a preparation process, a roughening treatment process, a fitting process, and a welding process.
In addition, since the preparatory process, fitting process, and welding process of 3rd Embodiment are the same as the preparatory process, fitting process, and welding process of 1st Embodiment, description is abbreviate | omitted.

(Roughening process)
The roughening treatment step is a step of forming fine irregularities on the fitting surface on the metal component side. According to this process, the resin melted in the welding process enters into the fine irregularities and the fixing strength is improved.
Examples of the method for forming fine irregularities on the fitting surface include a method of performing etching treatment or laser processing on the inner peripheral surface (fitting surface) of the fitting portion 21 of the housing 20. According to this etching process or laser processing, the inner peripheral surface of the fitting portion 21 is scraped (a fine concave portion is formed), and the entire inner peripheral surface becomes fine unevenness.

If the concave portion is formed on the inner peripheral surface by the above-described method, it is difficult for air to escape from the concave portion in the welding step, and there is a possibility that the molten resin does not flow into the concave portion or the amount that flows in is reduced (the possibility of air biting).
Therefore, in the welding process of 3rd Embodiment, it is preferable to weld using a frictional heat welding apparatus (an ultrasonic welding apparatus, a vibration welding apparatus). According to this frictional heat welding apparatus, the fitting portion 21 vibrates and air easily escapes from the inside of the recess, and the risk of air biting can be reduced.

Although the third embodiment has been described above, the welding process may be welding using a high-frequency induction device.
In the present invention, the roughening process is not limited to a negative type process that forms a recess in the fitting surface such as an etching process or laser processing. For example, a positive type process may be used in which a convex portion is provided by fixing a fine object on the fitting surface of the fitting portion 21 so that the fitting surface has fine irregularities. According to such a process, the air in the recesses can easily escape and the fixing strength can be reliably improved.

Although the first to third embodiments have been described above, the present invention is limited to the manufacture of a joined body (exterior part 9) in which a metal part (housing 20) is externally fitted to a resin part (rack cover 10). However, it can also be used to manufacture a joined body in which a metal part is fitted in a resin part.
Hereinafter, a joining method when a metal part is fitted into a resin part will be described.

As shown in FIG. 5, a fitted portion 11 </ b> A formed by stepping the inner peripheral surface is formed at the end of the rack cover 10 </ b> A. On the other hand, the housing 20A is provided with a fitting portion 21A having a smaller diameter than the fitted portion 11A by stepping the outer peripheral surface.
In such a configuration, in the fitting step, the fitting portion 21A of the housing 20A is fitted into the fitted portion 11A of the rack cover 10A. As shown in FIG. 5, in the welding step, the horn 30 of the ultrasonic welder is brought into contact with the outer peripheral surface of the fitted portion 11A of the rack cover 10A. According to this, the vibration of the horn 30 is transmitted to the fitted portion 11A, and frictional heat is generated at the interface between the inner peripheral surface 11c of the fitted portion 11A and the outer peripheral surface 21c of the fitted portion 21A opposite thereto. To do. Then, the inner peripheral surface 11c of the fitted portion 11A is melted, the fitted portion 11A and the fitted portion 21A are welded, and the fitted portion 11A and the fitted portion 21A are joined.

  Or as shown in FIG. 6, you may join the to-be-fitted part 11A and the fitting part 21A using the high frequency induction device and the pressurization apparatus 50. FIG. Specifically, in the welding step, the pressure roller 53 of the pressure device 50 is brought into contact with the outer peripheral surface of the fitted portion 11A of the rack cover 10A to press the fitted portion 11A radially inward ( (See arrow in FIG. 6). Next, the fitting portion 21A is arranged and activated in the coil portion 60 of the high-frequency induction device, and the fitting portion 21A generates heat by electromagnetic induction. According to this, the inner peripheral surface 11c of the fitted portion 11A pressed against the fitting portion 21A that generates heat is melted, the fitted portion 11A and the fitted portion 21A are welded, and the fitted portion 11A is fitted. The joining portion 21A is joined.

DESCRIPTION OF SYMBOLS 1 Steering device 2 Steering wheel 3 Steering shaft 4 Torsion bar 5 Pinion shaft 5a Pinion 6 Rack shaft 6a Rack 8 Rack end stud 9 Exterior parts 10, 10A Rack cover 11, 11A Fit part 20, 20A Housing 21, 21A fitting Part 30 Horn 40 Fixing jig 50 Pressure device 51 Rotating shaft 60 Coil part

Claims (5)

A method of manufacturing a joined body for producing a joined body of a resin part and a metal part,
Preparing the resin part made of thermoplastic resin having a fitted part, and the metal part having a fitting part that can be fitted to the fitted part;
A fitting step of fitting the fitting portion into the fitted portion;
In a state where the fitting portion and the fitting portion are fitted, the fitting surface of the fitting portion is melted while applying pressure to the fitting portion or the fitting portion by an external heating device. And welding step for welding the fitted portion and the fitting portion,
The manufacturing method of the conjugate | zygote characterized by including.   2. The method for manufacturing a joined body according to claim 1, further comprising a roughening treatment step of performing a roughening treatment on the fitting surface of the fitting portion after the preparation step and before the fitting step. The external heating device includes a pressurizing device for applying pressure to the fitted portion or the fitting portion, and a high-frequency induction device for heating the fitting portion,
The said welding process fuse | melts the said to-be-fitted surface by the heat_generation | fever of the said fitting part, The manufacturing method of the conjugate | zygote of Claim 1 or Claim 2 characterized by the above-mentioned. The external heating device is a frictional heat welding device that transmits vibration while applying pressure to the fitted portion or the fitting portion, and generates frictional heat on the fitted surface,
The said welding process fuse | melts the said to-be-fitted surface with the said friction heat, The manufacturing method of the conjugate | zygote of Claim 1 or Claim 2 characterized by the above-mentioned.   A joined body manufactured by the manufacturing method according to any one of claims 1 to 4.

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