JP5889726B2 - Steering wheel manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a steering wheel used for steering a vehicle.

  In addition to its function, the appearance of the vehicle steering wheel disposed in front of the driver's seat is also regarded as important. The surface of the steering wheel is generally composed of an outer member that covers the core metal, and the core metal is provided inside the steering wheel. When the steering wheel is manufactured by covering with a covering material (for example, a resin material), the core is formed by covering the core with the covering material, and the core is covered with a covering portion made of the covering material. On the other hand, conventionally, a steering wheel that maintains a light appearance by exposing a part of a core metal of a spoke is known (see Patent Document 1).

  When manufacturing the steering wheel provided with the exposed portion of the core metal by coating the covering material, the covering portion and the exposed portion are provided on the steering wheel by covering the covering material with a part of the core metal. In that case, an unnecessary part (burr etc.) which consists of covering materials may arise in the edge of the covering part adjacent to an exposed part.

FIG. 7 is a cross-sectional view showing the manufacturing procedure of the conventional steering wheel 100, showing the vicinity of the boundary between the covering portion 101 and the exposed portion 102. FIG. 7A is a diagram showing the core metal 103 when coating the coating material, FIG. 7B is a diagram showing the core metal 103 coated with the coating material, and FIG. 7C is an enlarged view of the Z portion of FIG. 7B.
At the time of manufacturing the steering wheel 100, the core metal 103 (see FIG. 7A) is disposed between the pair of molds 110 and 111, and the molds 110 and 111 are combined. At that time, the exposed portion 102 of the core metal 103 is sandwiched between the molds 110 and 111, and the space 112 filled with the coating material is part of the molds 110 and 111 and the core metal 103 (portion for forming the coating portion 101). Form between.

  Subsequently, the coating material is filled into the space 112, and the coating is performed while the coating material is coated on the core metal 103 in the space 112. Thus, a covering portion 101 (see FIG. 7B) made of a covering material is formed on the steering wheel 100. Thereafter, the molds 110 and 111 are released, and the steering wheel 100 is taken out of the molds 110 and 111. However, when the covering material is covered, the covering material enters between the molds 110 and 111 and the exposed portion 102, and an unnecessary portion (here, burr) 104 (see FIG. 7C) is generated at the edge of the covering portion 101. Sometimes.

  In order to maintain the appearance of the steering wheel 100, the unnecessary portion 104 needs to be removed from the edge portion of the covering portion 101 by a cutter or the like. However, as the unnecessary portion 104 is cut off, the exposed portion 102 may be damaged and the appearance of the steering wheel 100 may be impaired.

JP-A-10-119791

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to adjoin an exposed portion without impairing the appearance of the steering wheel at the time of manufacturing a steering wheel having a covering portion and an exposed portion of a core metal. It is to remove unnecessary portions generated at the edge of the covering portion.

  The present invention relates to a method for manufacturing a steering wheel, comprising a cored bar, a coating part made of a coating material coated on the cored bar, and an exposed part where the cored bar is exposed without being coated with the coating material, The step of disposing the protective member at the boundary position between the covering portion and the exposed portion, and covering the core metal with the covering material while exposing the exposed portion, and forming the edge of the covering portion adjacent to the exposed portion on the surface of the protective member A method for manufacturing a steering wheel, comprising: a step; a step of cutting off an unnecessary portion generated at an edge portion of a covering portion on a surface of a protective member; and a step of removing the unnecessary portion of the protective member and the cut off portion.

  According to the present invention, at the time of manufacturing a steering wheel provided with a covering portion and an exposed portion of a metal core, an unnecessary portion generated at the edge of the covering portion adjacent to the exposed portion is removed without impairing the appearance of the steering wheel. Can do.

It is a perspective view of the steering wheel of this embodiment. It is a perspective view which shows the internal structure of the steering wheel shown in FIG. It is a side view which shows the spoke part of a steering wheel. It is sectional drawing which shows the formation procedure of the coating | coated part of this embodiment. It is a figure which shows the removal procedure of the unnecessary part of a coating | coated part. It is a front view of the steering wheel of other embodiments. It is sectional drawing which shows the manufacturing procedure of the conventional steering wheel.

An embodiment of a method for manufacturing a steering wheel according to the present invention will be described with reference to the drawings.
The steering wheel is a steering member for the vehicle, and is disposed in front of the driver's seat and used for steering the vehicle. In the method for manufacturing a steering wheel according to this embodiment, the steering wheel is manufactured by covering with a covering material.

FIG. 1 is a perspective view of a steering wheel 1 of the present embodiment, and shows the steering wheel 1 as viewed from the vehicle occupant side. FIG. 2 is a perspective view showing an internal structure of the steering wheel 1 shown in FIG.
As shown in the figure, the steering wheel 1 includes a metal boss 2, a cover 3 provided at the center, an annular rim 4, and three spokes 5. Further, the steering wheel 1 includes a cored bar 10, a covering part 20 provided on a part of the cored bar 10, and an exposed part 6 made up of a part of the cored bar 10.

  The boss portion 2 is disposed inside the rim portion 4 and connected to a steering shaft (not shown). The cover 3 is formed in a bowl shape with resin, and is attached to the steering wheel 1 so as to cover the boss portion 2. The rim portion 4 is a grip that is gripped by an occupant when the steering wheel 1 is operated, and surrounds the boss portion 2. The spoke portion 5 is provided between the boss portion 2 and the rim portion 4 and is fixed to the boss portion 2 and the rim portion 4. The boss part 2 and the rim part 4 are connected by three spoke parts 5 arranged radially.

  The metal core 10 is a metal skeleton member of the steering wheel 1 and includes an annular rim metal core 11 and three plate-shaped spoke metal cores 12. The rim core metal 11 is provided on the rim portion 4 and surrounds the boss portion 2. The spoke mandrel 12 is provided in the spoke part 5 and connects the boss part 2 and the rim mandrel 11. The core metal 11 is integrally formed by casting a metal (for example, an aluminum alloy or a magnesium alloy), or is formed by joining the rim core metal 11 and the spoke core metal 12.

  The covering portion 20 is made of a covering material that covers the core metal 10, and includes an annular rim covering portion 21 and three spoke covering portions 22. The rim covering portion 21 is made of a covering material for the rim portion 4 covered on the rim core metal 11. The spoke covering portion 22 is made of a covering material for the spoke portion 5 covered on the spoke core metal 12. Here, the covering material is a moldable resin material, and is formed into a predetermined shape while being covered on a part of the surface of the core metal 10. The rim covering portion 21 and the spoke covering portion 22 are integrally formed by a mold and enclose the rim core metal 11 and the spoke core metal 12.

  In the exposed portion 6, a part of the core metal 10 is exposed without covering a part of the core metal 10 with the covering material. The exposed portion 6 is provided at a portion of the steering wheel 1 that can be seen by the passenger, and is exposed as a design on the surface of the steering wheel 1. Here, a part of the spoke core metal 12 is exposed without covering a part of the three spoke metal cores 12 with the covering material. Moreover, the spoke coating | coated part 22 is formed in the part by the side of the rim core metal 11 of the spoke metal core 12, and the part by the side of the boss | hub part 2 of the spoke metal core 12 is exposed.

FIG. 3 is a side view showing the spoke portion 5 of the steering wheel 1, and a part of the spoke portion 5 is schematically shown as viewed from the W direction in FIG.
The surface of the spoke portion 5 includes a spoke covering portion 22 on the rim portion 4 side and an exposed portion 6 on the boss portion 2 side. The exposed portion 6 is formed of a part of the spoke core metal 12 and is provided between the spoke covering portion 22 and the cover 3.

Next, the manufacturing procedure of the steering wheel 1 will be described.
First, the core metal 10 is produced, and surface treatment (painting, plating, etc.) is performed on the core metal 10. In addition, pretreatment is performed on the core metal 10 before coating the coating material, and the covering portion 20 is formed on the core metal 10 by injection molding using a mold.
FIG. 4 is a cross-sectional view showing the procedure for forming the covering portion 20 of the present embodiment, and shows the vicinity of the boundary between the covering portion 20 and the exposed portion 6. 4A is a view showing the cored bar 10 before coating the coating material, FIG. 4B is a diagram showing the cored bar 10 when coating the coating material, and FIG. 4C is an enlarged view of the portion X in FIG. .

  Prior to covering with the covering material (see FIG. 4A), the protection member 30 of the cored bar 10 is disposed on the cored bar 10 along the boundary between the coated part 20 and the exposed part 6 and attached to the surface of the cored bar 10. The protection member 30 is made of a thin member having a predetermined width, and is disposed at a boundary position K between the covering portion 20 of the core metal 10 and the exposed portion 6. The boundary position K is a position corresponding to the boundary between the covering portion 20 and the exposed portion 6 on the surface of the core metal 10, and the protection member 30 is attached to the surface of the core metal 10 at the boundary position K. At that time, the protection member 30 is disposed in a predetermined portion including the boundary position K of the cored bar 10, and the peripheral part of the boundary position K of the cored bar 10 is covered and protected by the protection member 30. Here, the protection member 30 is a band-shaped protective tape that is attached to the core metal 10 to protect the core metal 10. The protective tape is made of, for example, an adhesive tape, and is attached to the core metal 10 along the boundary between the covering portion 20 and the exposed portion 6. Further, the protection member 30 is disposed in a portion having a predetermined width of the cored bar 10 with the boundary position K as the center.

  By sticking the protective member 30 to the cored bar 10, the surface of the cored bar 10 is sealed. That is, the protection member 30 is also a seal member that seals the surface of the cored bar 10. When covering the covering material, the protection member 30 prevents the covering material from entering between the protection member 30 and the cored bar 10. Therefore, the covering material is not covered with the cored bar 10 but covered with the protecting member 30 in the portion where the protecting member 30 is attached. Further, the protection member 30 is maintained in a state of being attached to the core metal 10.

  After the protective member 30 is disposed (see FIGS. 4B and 4C), the pair of molds 40 and 41 provided in the injection molding machine (not shown) is separated, and the core metal 10 is disposed between the molds 40 and 41. . Next, the molds 40 and 41 are combined and brought into close contact with the core metal 10, and the exposed portion 6 of the core metal 10 is sandwiched between the molds 40 and 41. At the same time, a space 42 filled with the coating material is formed between the molds 40 and 41 and a part of the core metal 10 (portion for forming the coating part 20). At that time, the molds 40 and 41 are arranged from the exposed part 6 to the boundary position K of the cored bar 10, and the part of the protective member 30 on the exposed part 6 side is sandwiched between the molds 40 and 41 and the cored bar 10.

  A portion of the protective member 30 on the cover portion 20 side is disposed in the space 42. In this state, the softened coating material is injected into the space 42 by the injection molding machine to fill the space 42, and the coating material is molded in the space 42. As a result, the core metal 10 is covered with the coating material while exposing the exposed portion 6, and the coating material is cured. Thereafter, the molds 40 and 41 are released, and the core metal 10 is taken out from the molds 40 and 41.

FIG. 5 is a cross-sectional view showing the cored bar 10 covered with the covering material, and is a view showing a procedure for removing the unnecessary portion 25 generated in the covering portion 20 described later. 5A is a view showing the vicinity of the boundary between the covering portion 20 and the exposed portion 6, FIG. 5B is an enlarged view of a Y portion in FIG. 5A, and FIG. 5C is a view corresponding to FIG. 5B.
The covering portion 20 made of the covering material is formed on the cored bar 10 by the covering of the covering material (see FIGS. 5A and 5B). At that time, the covering material is covered on the entire rim core metal 11, and the rim covering portion 21 is formed on the entire rim core metal 11. At the same time, the covering material is covered on a part of the spoke core metal 12, and the spoke covering portion 22 is formed on a part of the spoke core metal 12. The spoke portion 5 is provided with a spoke covering portion 22 and an exposed portion 6.

  At the boundary position K of the cored bar 10, the edge portion 23 of the covering portion 20 (spoke covering portion 22) adjacent to the exposed portion 6 is formed on the surface 31 of the protection member 30 by covering with the covering material. The protection member 30 is disposed on both sides of the boundary position K along the boundary position K of the core metal 10, and the edge portion 23 of the spoke covering portion 22 is located at a position within the surface 31 of the protection member 30. 30 along the longitudinal direction (boundary position K). A portion of the protective member 30 on the side of the spoke covering portion 22 is covered with the spoke covering portion 22 (edge portion 23), and a portion of the protective member 30 on the side of the exposed portion 6 covers the exposed portion 6 outside the spoke covering portion 22.

  Further, when the covering material enters between the molds 40, 41 and the protection member 30 when the covering material is coated on the core metal 10, a burr 24 is generated at the edge 23 of the spoke covering portion 22. Thus, an extra portion (unnecessary portion 25) made of a covering material is generated at the edge portion 23 of the spoke covering portion 22. The unnecessary portion 25 is a portion unnecessary for the spoke covering portion 22, and includes an extra portion of the edge portion 23 (burr 24, a covering material protruding from the edge portion 23, etc.). That is, the unnecessary portion 25 is a surplus portion that is formed on the edge portion 23 by the surplus covering material when the covering material is covered.

  When the unnecessary portion 25 is generated at the edge portion 23 of the spoke covering portion 22, the unnecessary portion 25 is cut off from the edge portion 23 by cutting with a cutting means (cutter, knife, etc.) (not shown). At the time of cutting, the unnecessary portion 25 is cut off at the surface 31 of the protection member 30 without being cut off at the surface 6A of the exposed portion 6 so that the surface 6A of the exposed portion 6 is not damaged by the cutting means. In that case, the unnecessary part 25 is cut | disconnected toward the protection member 30, and it cuts along the edge part 23 (longitudinal direction of the protection member 30) on the protection member 30. FIG. Subsequently, the protective member 30 is removed from the spoke covering portion 22 while being peeled from the core metal 10 (see FIG. 5C), and the unnecessary portion 25 cut off from the protective member 30 is removed from the core metal 10 and the spoke covering portion 22. Thereby, the edge part of the surface 6A of the exposed part 6 is exposed, and the edge part 23 of the spoke covering part 22 is formed in a predetermined shape.

  Thereafter (see FIGS. 1 and 2), the boss 2 is fixed to the core 10 and the cover 3 and the like are attached to the core 10 and the boss 2. Moreover, an airbag apparatus is mounted on the steering wheel 1 as necessary. Thereby, manufacture of the steering wheel 1 provided with the metal core 10, the coating | coated part 20, and the exposure part 6 is completed.

  As described above, when the unnecessary portion 25 is generated at the edge portion 23 of the spoke covering portion 22, the unnecessary portion 25 is cut off at the surface 31 of the protective member 30. At this time, since the core metal 10 (exposed portion 6) can be protected by the protection member 30, it is possible to prevent the exposed portion 6 from being damaged when the unnecessary portion 25 is cut off. Therefore, the unnecessary portion 25 can be removed without impairing the appearance of the steering wheel 1, and a good appearance can be maintained. Moreover, since the unnecessary part 25 can be easily cut off by the surface 31 of the protection member 30, the labor and time of the cutting work can be reduced. By affixing the protective member 30 (protective tape) to the cored bar 10, the protective member 30 can be easily and reliably disposed at a predetermined position of the cored bar 10.

  When the unnecessary portion 25 is cut off at the surface 31 of the protection member 30, it is only necessary that the core metal 10 can be protected by the protection member 30, and the protection member 30 may be damaged. That is, the protection member 30 is a member that can protect the cored bar 10 when the unnecessary portion 25 is cut off, and is made of, for example, metal or resin. The cutting means for the unnecessary portion 25 cuts only the unnecessary portion 25 without cutting the protective member 30. When the protection member 30 is harder than the unnecessary portion 25, the protection member 30 is hardly cut when the unnecessary portion 25 is cut off. Therefore, it is desirable that the protection member 30 be a member that is harder than the unnecessary portion 25, and thus the exposed portion 6 of the cored bar 10 can be more reliably protected.

  The protection member 30 may be disposed on the entire boundary position K of the core metal 10 or may be disposed on a part of the boundary position K. When the protective member 30 is disposed at a part of the boundary position K, the protective member 30 is disposed at least on the occupant side portion of the core metal 10. Thereby, since the effort for arrange | positioning the protection member 30 is reduced, work efficiency can be improved, maintaining the external appearance of the steering wheel 1. FIG. By disposing the protection member 30 only on the occupant side portion of the core metal 10, the work efficiency can be further improved.

  When the protection member 30 is disposed at the boundary position K of the core metal 10, the entire protection member 30 may be attached to the surface of the core metal 10, and a part of the protection member 30 (for example, one or both edges) Part) may be affixed to the surface of the cored bar 10. However, the protection member 30 only needs to be disposed at the boundary position K when the covering material is covered, and the protection member 30 may not be attached to the cored bar 10. In this case, for example, the protection member 30 is brought into close contact with the surface of the core metal 10, and the protection member 30 is held on the core metal 10 by a holding member (holding adhesive tape, clip or the like). The holding member is provided at a position covered by the molds 40 and 41 (see FIG. 4), and is disposed between the molds 40 and 41 and the core metal 10 together with the protection member 30. After removing the cored bar 10 from the molds 40 and 41, the holding member is removed from the cored bar 10. On the other hand, the holding member may be positioned in the space 42 when the covering material is covered. For example, the holding member is covered with a covering material and becomes a part of the covering portion 20.

Next, a steering wheel 1 according to another embodiment will be described.
FIG. 6 is a front view of the steering wheel 1 according to another embodiment, and shows a part of the spoke part 5 and the rim part 4.
In this steering wheel 1, the surface 6A of the exposed portion 6 is a hairline processed surface 6B as shown in the drawing. The hairline process is a process for forming a large number of fine lines (hairlines) arranged in parallel, and is applied to the surface 6A of the exposed portion 6. The hairline on the hairline processed surface 6B is composed of a line in a direction along the cutting direction H of the unnecessary portion 25, and is formed on the entire surface 6A.

  At the time of manufacturing the steering wheel 1, the hairline processing in the direction along the cutting direction H is applied to the surface 6 </ b> A of the exposed portion 6 before the covering material is covered. Thereby, even if the surface 6A of the exposed portion 6 is slightly damaged due to the cutting off of the unnecessary portion 25, the scratch can be made inconspicuous. As a result, it is possible to prevent the appearance of the steering wheel 1 from being damaged.

  Although the example in which the exposed portion 6 is provided in the spoke portion 5 has been described above, the exposed portion 6 may be provided in a portion other than the spoke portion 5 of the steering wheel 1. For example, when the exposed portion 6 is provided on the rim portion 4, the covering material is covered on a part of the rim core metal 11, and the rim covering portion 21 is formed on a part of the rim core metal 11. Further, the exposed portion 6 where the rim core metal 11 is exposed is provided in the rim portion 4 without covering the other part of the rim core metal 11 with the covering material. When the unnecessary portion 25 is generated at the edge portion 23 of the rim covering portion 21 adjacent to the exposed portion 6, the unnecessary portion 25 is cut off from the rim covering portion 21 in the same manner as described above. In this manner, the covering portion 20 and the exposed portion 6 of the core metal 10 are provided on the steering wheel 1, and the unnecessary portion 25 generated at the edge portion 23 of the covering portion 20 is removed from the covering portion 20.

  DESCRIPTION OF SYMBOLS 1 ... Steering wheel, 2 ... Boss part, 3 ... Cover, 4 ... Rim part, 5 ... Spoke part, 6 ... Exposed part, 6A ... Surface, 6B ... -Hairline processed surface, 10 ... cored bar, 11 ... rim cored bar, 12 ... spoke cored bar, 20 ... covering part, 21 ... rim covering part, 22 ... spoke covering part , 23 ... edge part, 24 ... burr, 25 ... unnecessary part, 30 ... protective member, 31 ... surface, 40 ... mold, 41 ... mold, 42 ..Space, K ... Boundary position.

Claims (5)

A method of manufacturing a steering wheel comprising a cored bar, a coating part made of a coating material coated on the cored bar, and an exposed part where the cored bar is exposed without being coated with the coating material,
A step of disposing a protective member at a boundary position between the covering portion of the core metal and the exposed portion;
Covering the core metal with the covering material while exposing the exposed portion, and forming the edge of the covering portion adjacent to the exposed portion on the surface of the protective member;
A step of cutting off unnecessary portions generated at the edge of the covering portion on the surface of the protective member;
Removing the protective member and the unnecessary portion cut off;
A method of manufacturing a steering wheel having In the manufacturing method of the steering wheel according to claim 1,
A method for manufacturing a steering wheel, wherein the protective member is a member harder than an unnecessary portion of the covering portion. In the manufacturing method of the steering wheel according to claim 1 or 2,
A method for manufacturing a steering wheel, wherein the step of arranging the protective member includes a step of attaching the protective member to the surface of the core metal. In the manufacturing method of the steering wheel according to claim 3,
A method for manufacturing a steering wheel, wherein the protective member is a protective tape attached to a metal core. In the manufacturing method of the steering wheel according to any one of claims 1 to 4,
The manufacturing method of the steering wheel which has the process of giving the hairline process of the direction in alignment with the cutting direction of an unnecessary part to the surface of an exposed part.

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