JPH03187720A - Mold for grip and molding of grip - Google Patents

Abstract

PURPOSE:To minimize a parting line, which spoils the appearance or the high- class grip, and mold a high-quality grip by fixing a cavity mold having a flexibility along the inner wall of an opening type split mold. CONSTITUTION:A core pin 50 is set in a cavity mold 40 and non-expandable urethane resin is poured and filled into the cavity of the cavity mold 40 through the resin pouring port 36 of a split mold 30 and the resin supplying port 42 of the cavity mold 40 with a comparatively low pressure. In a stage wherein the urethane resin, filled into the cavity mold 40, is cured and a grip 60 is molded, the core pin 50 is retreated and a bottom force 32 and a top force 34, which are constituting the split mold 30, are opened with a pivotal shaft P as its center to separate and effect mold opening. The molded grip 60 is taken out of the cavity mold 40. The cylindrical grip 60, having a penetrating hole 62 for inserting the main body of a lever, is obtained. One piece of parting line 68 is formed at a position corresponding to the split surface (a) of the cavity mold 40 while the parting line 68 is formed at the lowermost end of the grip 60, which attracts least attention.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a mold and a method for molding lube such as a parking brake operating lever for a vehicle or a shift lever for shifting gears.

C. Prior Art] Conventionally, for example, the grip of a parking brake operating lever has been mainly formed by injection molding, and the mold used in this case has a cylindrical shape with an undercut. It is composed of a mold that can be divided into two along the .

FIG. 4 is an explanatory cross-sectional view showing an example of such a two-part mold, and FIG. 5 is an explanatory cross-sectional view taken along the line V-V in FIG. 4.

The two-split mold 1o includes a lower mold 1 that can be divided vertically.
2 and an upper mold 14, and a stepped core pin 16 is inserted and fixed in the axial direction of a cavity C in the mold. Further, a runner 18 for supplying molten resin into the cavity C is formed in the lower mold 12 and the upper mold 14.

When molding the grip, molten resin is injected into the cavity C via the runner 18, and when the resin solidifies, the lower mold 12 and the upper mold 14 are separated, and the core pin 16 is removed. As a result, a grip 20 having an undercut as shown in FIG. 6 is formed.

[Problems to be Solved by the Invention] As described above, the grip 20 is manufactured using the two-part mold 10.
In this case, two parting lines 22° 22 are formed on the surface of the grip 2o. It is said that such a parting line 22 spoils the beauty and luxury of the design, especially the high-quality grips for operating the parking brake that accompany the trend toward luxury in automobiles in recent years, and cannot adequately respond to the trend toward luxury as described above. I have a problem.

The present invention solves these problems, and its purpose is to minimize the parting lines that impair the beauty and luxury of the grip, and to provide a high-quality grip that is excellent in terms of design and texture. An object of the present invention is to provide a mold and a molding method that can form a mold.

[Means for Solving the Problems] In order to solve the above problems, the mold of the present invention is a mold for molding a grip made of resin or rubber by injection molding. An open-mouth split molding mold is rotatably supported and fixed, and the other end sides of the upper mold and lower mold can be opened and closed. A cavity mold with one end open and integrally provided along the inner wall of the cavity of the split mold, with the split surface of the cylindrical body and the split surface of the split mold coinciding with each other. and a core pin forming a through hole along the axial direction of the grip to be molded.

Further, the molding method of the present invention is a grip molding method for molding a resin or rubber grip by injection molding, and is characterized by including the following steps (a) to (C).

(a) A core pin is inserted and arranged along the axial direction of a flexible cavity mold that is integrally provided in the cavity of the split mold.

(b) A grip is formed by injecting resin or rubber into the cavity mold.

(c) The split mold and the cavity mold are integrally opened, and the mold grip inside is removed.

[Function] In the present invention, a one-end open type cavity mold made of rubber or elastomer is integrally provided along the inner wall of the cavity of an open-mouth split mold, and a grip is molded using this cavity mold. The two parting lines formed when using a conventional two-part mold can be reduced to one, and a grip with excellent aesthetic appearance can be molded. Further, by forming the split mold and the cavity mold so that the parting line is formed on the lower end side of the grip, the parting line can be formed in a state where it is almost inconspicuous.

Since the cavity mold is made of rubber or elastomer with excellent flexibility and resilience, it can sufficiently handle deformation when the mold is opened and can be used repeatedly. be.

[Embodiment N] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory cross-sectional view showing an example of a mold for implementing the molding method of the present invention, and FIGS. 2 (A) and (B) are explanatory views showing a process for molding a grip. , FIG. 2(A) is an explanatory cross-sectional view taken along the line ■-■ in FIG. 1.

The split mold 30 of this embodiment is shown in FIGS. 1 and 2 (A
), it is composed of a lower mold 32 and an upper mold 34, one end of which is supported and fixed by a rotating shaft P, and a cavity mold 40 that defines the outer shape of the grip to be molded along the inner wall of the cavity is integrally formed. Further, a core pin 50 is inserted and fixed along the axial direction of the cavity mold 40.

The rotation shaft P is provided in contact with the cavity mold 40 at the dividing surface between the lower mold 32 and the upper mold 34 that constitute the divided mold 30. Parts 32a, 34 of the side wall surfaces of the lower mold 32 and the upper mold 34 on the rotation axis P side
a has a tapered shape inclined toward the rotation axis P;
It is configured so as not to impede the rotational movement of the lower mold 32 and the upper mold 34.

Further, a resin injection port 36 for supplying molten resin into the cavity C of the cavity mold 40 is formed on one side in the axial direction of the lower mold 32 and the upper mold 34 that constitute the split mold 30. The resin injection port 36 has a tapered side wall surface whose diameter increases toward the end surface of the split mold 30. Further, on the other side of the split mold 30 in the axial direction, a core pin insertion portion 38 into which the tip end portion of the core pin 50 is inserted and supported is formed.

The cavity mold 40 is constructed by dividing a part of a cylindrical body in the axial direction, which has a cavity C defining the outer shape of the grip to be molded. And this cavity type 4
A plurality of locking portions 48 are formed on the outer circumferential surface of 0, and the locking portions 48 are wedge-shaped and become wider toward the outside. In addition, an engaged recess 3.9 is formed in the inner wall of the lower mold 32 and the upper mold 34, and the engaged recess 3.9 has a shape that widens toward the end and corresponds to the shape of the locking portion 48. By inserting and locking the portion 48, the cavity mold 40 is supported and fixed along the inner wall of the split mold 30. In this state, as shown in FIG. 2(B), the dividing surface a of the cavity mold 40 and the dividing surfaces of the lower mold 32 and the upper mold 34 constituting the divided mold 30 are configured to be flush with each other. has been done. In this embodiment, the shapes of the split mold 30 and the cavity mold 40 are designed so that these split surfaces a and b are located at the lowest end of the grip 60 to be molded.

Further, a resin supply port 42 that communicates with the resin injection port 36 is formed on one side of the cavity mold 40 in the axial direction, and a resin supply port 42 that communicates with the resin injection port 36 is formed on the other side of the cavity mold 40 in the axial direction.
A core pin insertion hole 44 is formed into which the core pin is inserted.

The cavity mold 40 is made of synthetic rubber having excellent flexibility, restorability, and heat resistance, such as silicone rubber or fluorine rubber. Such a cavity mold 40 can be created by casting transfer from a prototype of an integrally processed grip or a leather-wrapped grip that does not have joints or parting lines. In this example, in order to texture the surface of the grip to be molded,
Fine protrusions 46 are formed on the inner wall of the cavity mold 40.

The core pin 50 is configured to be movable in the horizontal direction by a drive means (not shown), and is configured from a metal rod. Two stages of small diameter portions 52 and 54 are formed on the tip side of the core pin 50. The small diameter portion 54 located at the tip end is inserted into the core pin insertion opening 44 of the cavity mold 40 and further inserted into and fixed to the core pin support portion 56 fitted into the core pin insertion portion 38 .

Next, the method of forming the grip 60 is shown in FIG. 2(A).
, (B).

(A) First, the core pin 50 is set in the cavity mold 40, and the core pin 50 is inserted into the cavity mold 4 through the resin injection port 36 of the split mold 30 and the resin supply port 42 of the cavity mold 40.
A non-foaming urethane resin is injected and filled into the cavity C of No. 0 at a relatively low pressure.

However, the type of resin constituting the grip is not particularly limited, and either foamable or non-foamable resin can be used. Then, the pressure at the time of resin injection is set depending on the type and type of resin used.

(B) At the stage when the urethane resin filled in the cavity mold 40 has hardened and the grip 60 has been molded, the core pin 5
At the same time, the lower mold 32 and the upper mold 34 constituting the split mold 30 are opened and separated about the rotation axis P, and the mold is opened. Then, the molded grip 60 is taken out from the cavity mold 40.

In this way, a cylindrical grip 60 having a through hole 62 for inserting the lever body along the axial direction can be obtained. This grip 60 has one parting line 68 at a position corresponding to the dividing surface a of the cavity mold 40.
is formed, and this parting line 68 is
As shown in FIG. 3, it is formed at the lowest end of the grip 60 where it is least noticeable. Also, this grip 60
A grain-like recess 64 is formed on the surface of.

Next, the operation of this embodiment will be explained.

In the above embodiment, a synthetic rubber cavity mold 40 with one end open is fixed along the inner wall of the split mold 30, and the grip 60 is molded using this cavity mold 40, thereby replacing the conventional two-part mold. Two parting lines formed when used can be reduced to one. By forming this parting line at an inconspicuous position, a grip 60 with excellent aesthetic appearance can be formed.

Moreover, since the cavity mold 40 is made of synthetic rubber with excellent flexibility and restorability, it can easily follow the opening and closing operations of the split mold 30. Furthermore, the cavity mold 40 is excellent not only in flexibility and restorability but also in heat resistance, so that it can be used repeatedly.

Although one embodiment of the present invention has been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the gist of the invention.

For example, in the above embodiment, a case was explained in which synthetic rubber was used as the mold material for the cavity mold 40, but since synthetic rubber has relatively poor durability and is suitable for small quantity production, when the purpose is mass production. In this case, a resin elastomer with low material cost can be used as the mold material for the cavity type. In this way, when using elastomer as the material for the cavity mold, after using it as the cavity mold,
This can be crushed and reused.

Further, the material constituting the grip 60 is not limited to resin as in the above embodiments, but rubber or the like may also be used.

Further, the split mold and the cavity mold can take various forms depending on the shape of the grip to be molded.

Furthermore, in the above embodiments, a case has been described in which the present invention is applied to the molding of a grip of a parking operating lever, but the present invention is not limited to this, but can also be applied to a grip of a gear shift lever, etc.

[Effects of the Invention] According to the present invention, by fixing a flexible cavity mold along the inner wall of an open-mouth split mold,
Parting lines that impair the appearance and luxury of the grip can be minimized, and a high-quality grip can be molded.

[Brief explanation of drawings]

Figure 's1 is a cross-sectional explanatory view showing an example of a preferred mold of the present invention, Figures 2 (A) and (B) are explanatory views showing a process for molding a grip, and Figure 2 ( A) is ■ in Figure 1
-■ A cross-sectional explanatory view of a cut plane, FIG. 3 is a perspective explanatory view showing an example of a grip molded by the mold shown in FIGS. 1 and 2, and FIGS. 4 and 5 are a conventional split FIG. 6 is a perspective explanatory view showing a grip molded by the mold shown in FIGS. 4 and 5. FIG. 30... Divided mold, 32... Lower mold, 34... Upper mold, 40... Cavity mold, 50... Core pin, 6
0...Grip, 68...Parting line, C
···cavity.

Claims (3)

[Claims] (1) In a mold for molding a resin or rubber grip by injection molding, one end of the upper mold and the lower mold is rotatably supported and fixed, and the other end of the upper mold and the lower mold is formed so that it can be opened and closed. It is constructed by dividing a part of a flexible cylindrical body made of rubber or elastomer in the axial direction, and a dividing surface of this cylindrical body and a dividing surface of the divided molding die. a core pin that forms a through hole along the axial direction of the grip to be molded; and a core pin that forms a through hole along the axial direction of the grip to be molded. A grip mold that is characterized by: (2) A grip mold according to claim (1), wherein the divided mold and the dividing surface of the cavity mold are provided corresponding to the lowermost end of the grip to be molded. (3) In the grip molding method of molding a resin or rubber grip by injection molding, the following steps (
A method for molding a grip, comprising steps a) to (c). (a) A core pin is inserted and arranged along the axial direction of a flexible cavity mold that is integrally provided in the cavity of the split mold. (b) A grip is formed by injecting resin or rubber into the cavity mold. (c) The split mold and the cavity mold are integrally opened, and the mold grip inside is removed.