JP4570041B2 - Steering wheel and molding apparatus therefor - Google Patents

Description

  The present invention relates to a steering wheel having alternately a hard grip portion and a soft grip portion and a molding apparatus therefor.

Conventionally, a steering wheel is known in which leather is disposed around a soft portion with a so-called combination handle formed of a hard portion and a soft portion covering a core metal (Patent Document 1).
However, this method for manufacturing a steering wheel requires two molds, that is, a mold 1 for molding a hard part and a mold 2 for molding a soft part, and two molding steps. For this reason, there is a problem that productivity is inferior not only in terms of time required for work and in terms of production equipment but also in terms of necessary space for production equipment, and production costs are increased accordingly.

In addition, in the structure described in Patent Document 1, leather is wrapped around the soft part, and the end of the leather is grained into the groove formed in the hard part. However, since both sides of the groove part are hard parts, The work of inserting a leather terminal is troublesome and has a problem in terms of workability. It is necessary to design the size of the groove as small as possible in order to improve the appearance because the gap is larger than the thickness of the leather. However, the narrower the groove, the harder the grain of the leather ends are. Because it becomes.
JP-A-10-226338

  Under such circumstances, the present invention provides a steering wheel having a structure suitable for wrapping a soft gripping part of leather in a combination handle, and an object thereof is to provide a molding apparatus for manufacturing the steering wheel. To do.

  As a result of diligent study, the present inventor is effective to arrange a groove portion provided for embedding a skin sheet for decorating the soft gripping portion between the hard gripping portion and the terminal portion facing the soft gripping portion. As a result, the present inventors have found that the hard gripping portion and the soft gripping portion can be molded with a single mold by improving the structure of the runner of the molding apparatus.

That is, the present invention
[ 1 ] A steering wheel in which a hard gripping portion and a soft gripping portion are alternately formed on a ring-shaped ring portion over a predetermined circumference in the circumferential direction. A steering wheel molding apparatus having a groove formed between,
The apparatus includes a runner on the mold PL surface, and a hard gripper runner and a soft gripper runner are provided independently on the PL surface, the hard gripper runner and the soft gripper runner, A steering wheel molding device, characterized in that the runner is crossed by providing a cross block for three-dimensionally crossing both at the crossing part of
[ 2 ] The steering wheel molding according to [ 1 ], wherein the head portion for injecting the resin material of the apparatus into the mold can switch connection with the runner for the hard gripping portion or the runner for the soft gripping portion. apparatus,
[ 3 ] The mold includes a cavity for a hard gripping part and a cavity for a soft gripping part formed around the cored bar insert, and a groove forming part located at the boundary between these cavities is brought into contact with the cored bar insert. The present invention relates to a steering wheel molding apparatus according to [ 1 ] or [ 2 ], wherein the steering wheel molding apparatus has a seal portion for sealing.

  The steering wheel according to the present invention is provided with a groove for wood graining the end of the skin sheet covering the soft gripping portion on the opposing surface (boundary surface) between the hard gripping portion and the soft gripping portion, so that the soft gripping during the graining operation Since the portion can be elastically deformed to temporarily widen the gap between the grooves, the operation can be easily performed. In addition, the elastic deformation of the soft gripping part is restored after the graining of the skin sheet, and the skin sheet terminal is pressed against the hard gripping part, so that the graining terminal part is securely fixed, and as a result, the hard gripping part and the soft gripping part are pressed. The parting with the club can be finished nicely.

In addition, the molding apparatus of the present invention is provided with an intersection block that three-dimensionally intersects the two runners in the mold so that the hard gripper runner and the soft gripper runner are placed on the PL surface of the mold. Can be provided independently of each other, and in the past, two molds were used to form these two gripping portions, and two processes were required for molding in a single mold. Molding was possible. Therefore, according to the apparatus of the present invention, the productivity of the steering wheel in which the hard gripping portions and the soft gripping portions are alternately arranged can be greatly improved.
Furthermore, as a resin injection head, a resin injection head capable of switching between a resin injection head part for forming a hard gripping part and a resin injection head part for forming a soft gripping part is provided, so that molding by one injection molding machine is possible. This makes it possible to further simplify the molding apparatus and further rationalize it.

The resin material used in the present invention is not particularly limited, and a hard resin and a soft resin that have been conventionally used for forming a steering wheel can be used, but particularly preferable ones are both a hard resin and a soft resin. RIM molding with polyurethane resin.
As is well known, the polyurethane resin material is formed by a polyaddition reaction of a polyol component and an isocyanate component. Usually, from these two basic component injection machines, from a molding machine equipped with a third component injection machine containing a foaming agent (such as water), a hard component (such as ethylene glycol), and a colorant as the third component to the mold Molding is performed by supplying a molding material. In the present invention, the third component injection machine is prepared for the soft part and the hard part. For the soft part, the hard component is not blended or the blending of the foaming agent is reduced. In addition, for the hard part, a material having a compounding formulation in which the compounding of the hard component is increased and the foaming agent is not compounded or the compounding is reduced is used.

  In the present invention, if the total amount of the component that reacts with the two isocyanate components of the foaming agent and the hard component in the two third component injectors is equalized, the two basic component injectors inject. By switching only the third component at the time of injection without changing the blending ratio of polyol and isocyanate, the molding materials for the hard gripping portion and the soft gripping portion can be sequentially injected. When molding is performed by such a method, a third component injection switching valve is provided between the two third component injection machines and the molding material injection head attached to the mold to switch the molding material flow path in the mold. By combining the means, a steering wheel having a hard gripping portion and a soft gripping portion can be formed with a single mold with a single molding machine.

In the molding apparatus of the present invention, it is important to provide a hard gripping part runner and a soft gripping part runner in the mold, and to provide an intersecting block for three-dimensionally intersecting these two runners.
In the case of a steering wheel in which a hard gripping part and a soft gripping part are arranged one by one, two molding material flow paths (runners) from the molding material injection port to each mold holding part cavity intersect. It can arrange | position to a metal mold | die without making it. However, in the case of a steering wheel in which a plurality of hard gripping portions and soft gripping portions are alternately arranged as in the present invention, the runners intersect, and the molding material for the hard portion and the molding material for the soft portion Are simultaneously injected into the mold, the two molding materials are mixed at this portion. Alternatively, when the molding material for the hard part and the molding material for the soft part are sequentially injected into the mold, each molding material enters both runners at this intersection, and in each case, a predetermined plurality A steering wheel having alternating hard grip portions and soft portion grip portions cannot be formed.

Therefore, in the present invention, as described above, a crossing block that three-dimensionally crosses these two runners is disposed at a portion where the hard gripping portion runner and the soft gripping portion runner intersect. Due to the arrangement of the intersecting blocks, a steering wheel having a plurality of hard gripping portions and soft gripping portions alternately can be formed with a single mold.
This cross block is a block piece having two flow paths, and one (front side) flow path is connected to the hard material runner, and the other (back side) flow path is connected to the soft material runner. . With this block piece, the two flow paths can be secured independently of each other, avoiding mixing of the two and unintentional injection into the cavity.
When the product is taken out from the mold after molding, the block piece is raised, and the soft runner on the back side can be easily cut by the operator.

In addition, the boundary portion between the hard gripping portion and the soft gripping portion is formed by providing a soft resin part cut-off shape at the end of the hard gripping portion formed in the first step in a normal steering wheel, and softening in the second step. The molding material leakage at the time of molding the grip portion is prevented.
In the present invention, when the dimensional accuracy of the core metal inserted into the mold at the time of molding is high, the convex shapes projecting from the portions corresponding to the parting portions of the hard resin and the soft resin of both molds, respectively. This is divided into a hard part and a soft part block by abutting against and contacting the cored bar at the time of mold clamping, and each block is hard and soft. The molding material is injected sequentially or simultaneously. In addition, when the dimensional accuracy of the core metal is not so high, a convex shape protruding from each of the portions corresponding to the parting part of the hard resin and the soft resin of both molds is provided, and this convex part is epoxy-based, By placing a sealing material made of urethane, etc., when the mold is closed, this sealing material elastically deforms and closes the gap with the cored bar, so that each block of hard and soft parts in the cavity space in the mold Can be divided. Thus, in the present invention, a steering wheel having a plurality of hard gripping portions and soft gripping portions alternately in one process using a single mold can be manufactured with excellent productivity.

  The cored bar will be exposed at the cut-off part of the hard part and soft part formed at this time, but when the skin sheet is wrapped around the soft part, the end part of the skin sheet will be grained into this exposed gap Therefore, it does not impair the appearance of the completed steering wheel. Rather, the elasticity of the soft part can be used during the graining work of the skin sheet, facilitating the work, and securing the terminal part reliably and nicely. Further, it is possible to further secure the fixing of the skin sheet terminal portion by applying an adhesive to the exposed core metal.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view showing an example of a mold of the molding apparatus of the present invention. In FIG. 1, 1 is a mold, 2 is a molding material injection head, 3 is a pipe for polyol, 4 is a pipe for isocyanate, 5 is a pipe for a third component (foaming agent such as water) for forming a soft polyurethane gripping part, 6 Is a pipe for a third component (hard component such as ethylene glycol) for forming a hard polyurethane gripping part, 7 is a third component switching valve, and 8 is a cross block piece that three-dimensionally intersects the runner for hard material and the runner for soft material. , 9 is a hard material runner, 10 is a soft material runner, 11 is a hard gripping part, 12 is a soft gripping part, and 13 is a cored bar.

  FIG. 2 is a cross-sectional explanatory view taken along the line A-A in FIG. FIG. 3 is a perspective view showing an example of the cross block piece. 2 or 3, hard material is injected from the near side to the other side, and soft material is injected from the right side to the left side through the lower side of the cross block piece. FIG. 4 is an explanatory view of the steering wheel of the present invention, and is a cross-sectional explanatory view of a boundary portion between the hard gripping portion 11 and the soft gripping portion 12. The state where the end of the leather 17 which is the skin sheet is fixed to the groove 15 in the gap at the boundary is fixed. In FIG. 4, the adhesive 16 is applied to the cored bar.

The molding process of the steering wheel of the present invention will be described in order as follows.
First, the core bar 13 is set in one mold 1. Like the one mold, the convex portion protruding so as to contact the cored bar 13 between the hard gripping portion 11 and the soft gripping portion 12 has a convex portion provided with an epoxy or urethane sealant. After the other mold is closed to form a cavity for the hard gripping part and the soft gripping part, a polyurethane molding material for the soft gripping part is injected. At this time, the switching valve 7 is operated so that the pipe 5 for the third component (foaming agent such as water) for forming the soft polyurethane gripping portion is connected to the molding material injection head 2. A polyol, polyisocyanate, and a third component are mixed in the head 2, passed through a soft material runner 10 connected to the head, and injected into a soft gripping portion cavity in the mold to cover the core metal 13 and soften it. The grip part 12 is formed. Next, the head 2 is slid and connected to the hard material runner 9, and the switching valve 7 is switched to the hard polyurethane gripping part forming third component (hard component such as ethylene glycol) pipe 6, and the head is made hard. The third component is supplied and mixed with the polyol and polyisocyanate in the same manner, and is passed through the hard material runner 9 to be injected into the hard gripper cavity in the mold, and the core metal 13 is covered to cover the hard gripper 11. Is molded. After curing both gripping parts, the mold is opened and the polyurethane resin remaining on the steering wheel and each runner part is taken out.
At this time, the cross block piece is moved from the PL surface to the outside of the mold PL surface, the hard polyurethane of the hard runner 9 is removed from the mold, and the soft polyurethane of the soft runner 10 on the back side of the cross block piece 8 is pulled. Remove and remove from mold.

Comparing the time required for molding the steering wheel by the present molding method and the conventional molding method in this way, the method of the present invention was able to carry out all the steps in a total of 210 seconds, whereas the conventional method could The method of using two molds and molding in two steps required a total of 417 seconds.
In addition, the order of injection | pouring of a soft polyurethane and a hard polyurethane can be selected suitably.
Further, as in the above-described embodiment, an epoxy-based or urethane-based sealing material is provided on the protruding portion that protrudes so as to contact the cored bar 13 between the hard gripping portion 11 and the soft gripping portion 12 as in the case of one mold. The mold having the convex portion provided with the mold is closed to form a cavity for the hard gripping portion and the soft gripping portion, and then a polyurethane molding material for the soft gripping portion is injected to form a polyurethane molding material for the soft gripping portion. While the fluid is still in fluidity, the soft gripping part is extended by slightly separating the convex part from the cored bar 13, and then the hard part in the mold is operated by the same operation as in the above embodiment. The steering wheel shown in FIG. 5 can be molded by injecting a polyurethane molding material for the hard gripping part into the gripping part cavity, covering the core bar 13 and molding the hard gripping part 11.
Moreover, in the said Example, although the injection | pouring head 2 is slid and the connection to the runner 9 for hard and the runner 10 for softness is switched, as shown in FIG. Alternatively, a valve for switching injection of the soft molding material and the hard molding material indicated by 14 may be built in and this valve 14 may be used.

The soft gripping portion 12 of the steering wheel formed in this way is normally held by a driver when the vehicle is going straight, and the touch of this portion is important. At least the soft gripping portion 12 has a skin sheet such as leather. Is preferably wound. This skin sheet is wound and fixed by an adhesive or stitching. Further, the end of the skin sheet is fixed to the groove with wood grain. In that case, it is preferable to fix through an adhesive.
Further, in order to further improve the appearance, fluid printing can be applied to the hard gripping portion 11 of the steering wheel that does not cover the skin sheet in order to give a wood grain pattern.

Explanatory drawing which shows an example of the shaping die in the shaping | molding apparatus of this invention. FIG. 1A-A cross-sectional explanatory diagram. The perspective view which shows an example of an intersection block piece. It is explanatory drawing of the steering wheel of this invention, and is sectional explanatory drawing of the boundary part of a hard holding part and a soft holding part. Explanatory drawing of another Example same as the above. Explanatory drawing which shows another Example of the shaping die in the shaping | molding apparatus of this invention.

Explanation of symbols

1: Mold 2: Injection molding material injection head 3: Pipe for polyol 4: Pipe for isocyanate 5: Third component for forming a flexible polyurethane gripping part (foaming agent)
6: Third component for forming a rigid polyurethane grip (hard component)
7: Third component switching valve 8: Cross block piece 9 that three-dimensionally intersects the hard material runner and the soft material runner 9: Hard material runner 10: Soft material runner 11: Hard grip portion 12: Soft grip portion 13 : Core 14: Valve for switching injection of soft molding material and hard molding material

Claims (3)

A steering wheel in which a hard grip portion and a soft grip portion are alternately formed on a ring-shaped ring portion over a predetermined circumferential length, and a groove portion is provided between terminals facing the hard grip portion and the soft grip portion. A steering wheel molding device formed with
The apparatus includes a runner on the mold PL surface, and a hard gripper runner and a soft gripper runner are provided independently on the PL surface, the hard gripper runner and the soft gripper runner, A steering wheel forming apparatus, characterized in that a crossing block is provided for crossing the two at a crossing portion to cross the runner. The head portion of the resin material is injected into the mold apparatus, a steering wheel molding apparatus according to claim 1, wherein the can switch the connection between a rigid gripper runner or soft gripper for runners. A seal in which a mold has a cavity for a hard gripping part and a cavity for a soft gripping part formed around a cored bar insert, and seals a groove forming part located at a boundary between the cavity and the cored bar insert molding apparatus of a steering wheel of claim 1, wherein it has a part.

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