JPH03258528A - Manufacture of mounting seat of resin - Google Patents

Abstract

PURPOSE:To avoid undercut, and thus prevent the occurrence of deformation or wear in a projected part by forming the surface of the projected part to be undercut by a split mold. CONSTITUTION:There is provided a pair of guide walls projecting mutually oppositely from the general surface of an attaching part, a ceiling part 13 having an attaching hole 15 and being suspended between the paired guide walls, and a projected part 14 provided on at least either one of the ceiling part 13 or the general surface and projected toward the other of the general surface and ceiling part 13. Fastening materials (nut) such as nuts and the like are accommodated in the space being encircled by the guide walls and the ceiling part 14 and, in the case of manufacturing a resin mounting seat for preventing the fastening materials from falling from the space at the projected part 14, a projected part is formed with one split mold 2 and a slide core 4 by the use of a pair of split molds 2, 3 and the slide core 4. Furthermore, relative to the removing direction of the slide core 4, the surface of the projected part to be undercut is formed at least by one of the split molds.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of manufacturing a mounting seat for holding a fixing member such as a nut, and more particularly to a method of manufacturing a mounting seat that has a protrusion inside thereof to prevent falling off.

[Prior Art] For example, when fixing a mounting part such as an automobile molding to a car body, as shown in FIGS. That is, the mounting seat 100 includes a pair of guide walls 103 that protrude parallel to each other from the general surface 101 of the mounting part, and a ceiling that has a mounting hole 104 and is constructed between the guide walls 103. One end of the guide wall 103 is connected to form a U-shape as a whole, and an opening 102 is formed at the other end.

Further, a convex portion 106 that protrudes toward the general surface 101 is formed on the opening 1.02 side of the mounting hole 104 of the ceiling portion 105 . The nut 200 is accommodated through the opening 102 in a space surrounded by the guide wall 103 and the ceiling 105, and the nut 200 is prevented from falling out of the opening 102 by the convex portion 106.

Then, the bolt 202 inserted through the vehicle body steel plate 201 is screwed into the nut 200 through the mounting hole 104, so that the ceiling portion 105 is held between the nut 200 and the vehicle body steel plate 201, and the attached component is fixed.

Other known structures for such mounting seats include those disclosed in, for example, Japanese Unexamined Patent Publication No. 60-203547.

[Problems to be Solved by the Invention] By the way, the space surrounded by the moat where the mounting seat is formed from resin by molding, the guide part 103 and the ceiling part 105 needs to be formed by a slide core that enters and exits from the opening 102. However, at this time, the convex portion 106 becomes undercut, making it difficult to pull out the slide core. However, since there is no solution to this problem, conventionally the height of the convex portion 106 has been reduced and the slide core has been forcefully removed. Therefore, the convex portion 106 may become deformed or worn out, and the nut 2
The retainability of the fixing member such as 00 was insufficient.

The present invention was made in view of these circumstances, and
The convex part undercuts the slide core during mold release.
The purpose is to avoid this.

[Means for Solving the Problems] A method for manufacturing a resin mounting seat of the present invention that solves the above problems includes a pair of guide walls that protrude from the general surface of the mounting part in opposition to each other, and a take-in hole. A ceiling part constructed between a pair of guide walls, and a convex part provided on at least one of the ceiling part and the general surface and protruding toward the other of the general surface and the ceiling part, and surrounded by the guide wall and the ceiling part. A method for manufacturing a resin mounting seat that accommodates a fixing member such as a nut in a space and prevents the fixing member from falling out of the space with a convex portion, the method comprises: using a pair of split molds and a slide core; The split mold and the slide core form a convex part, and the surface of the convex part which becomes an undercut with respect to the direction in which the slide core is pulled out is formed on at least one of the split molds.

The inner peripheral surface of the mounting hole in the ceiling can be a surface parallel to the mold opening direction. Therefore, the mounting hole is conventionally formed on one side of the split type, thereby preventing the mounting hole from being undercut with respect to the slide core. On the other hand, regarding the convex portion, conventionally, the entire surface of the convex portion is formed of a slide core, so undercuts inevitably occur. The present inventors focused on this difference and completed the present invention by recollecting the idea of forming a surface of the convex portion which becomes an undercut in the direction in which the slide core is pulled out on one side of the split mold.

That is, the manufacturing method of the present invention is characterized in that a convex portion is formed by one of the split molds and the slide core. As a result, the surface of the convex portion, which would normally result in an undercut, can be formed on one side of the split mold, and undercuts can be avoided. The surface of the convex portion may be formed using only one of the split molds, or may be formed using both of a pair of split molds.

In the case of a moat forming a convex part with a split type for forming a mounting hole, the undercut surface of the convex part forms the same surface as the inner circumferential surface of the mounting hole.

The material of the mounting seat is PP, PE, AB as before.
Various materials such as S can be used, and the molding method is not particularly limited.

[Operations and Effects of the Invention] In the manufacturing method of the present invention, the surface of the convex portion, which normally becomes an undercut, is formed by a split mold. Therefore, undercuts can be avoided, so deformation and wear of the convex portions will not occur.

This makes it possible to improve workability when releasing the mounting seat from the mold, and the mounting seat also has excellent ability to hold the fixing member, thereby reliably preventing it from falling off.

[Example] Hereinafter, this will be explained in detail using examples.

FIG. 1 is a perspective view of a main part of a mounting component having a mounting seat obtained by the manufacturing method of this example, and FIG. 2 is a sectional view thereof. This mounting seat 1 includes a pair of guide walls 11 that protrude from a general surface 10 of the mounting part in parallel to each other, a bottom wall 12 that connects one end of the pair of guide walls 11 to each other, and a general surface 10. It is composed of a ceiling part 13 extending in parallel and installed between guide walls 11, and a convex part 14 protruding from the inner surface of the ceiling part 13 toward the general surface 10 side. Further, an elongated mounting hole 15 is formed in the ceiling portion 13, and a bolt hole 16 is formed in the general surface 10 facing the mounting hole 15. A surface 14a of the convex portion 14 perpendicular to the ceiling portion 13 constitutes a part of the inner circumferential surface of the attachment hole 15.

The structure of the mold used to manufacture this mounting seat 1 is shown in cross section in FIGS. 3 to 5. This mold is composed of an upper mold 2, a lower mold 3, and a slide core 4.

The upper mold 2 has a convex part 20 forming a mounting hole 15 and a bolt hole 16, and the slide core 4 has a bifurcated shape that slides on both sides of the convex part 20. A convex cavity 42 that forms the convex part 14 is formed between the bifurcated base of the slide core 4 and the convex part 20, and a part of the surface of the convex part 20 forms the surface 14a of the convex part 14. It makes up the surface.

In the mold configured in this way, the upper mold 2 and the lower mold 3 are clamped, and the slide core 4 is advanced to come into contact with the convex mold part 20. In this state, molten PP is placed in the cavity to form a copper mine. As a result, the mounting seat 1 is formed, and the convex portion 14 is formed in the convex cavity 42.

Next, the slide core 4 is slid in the direction of the arrow in the figure, the upper mold 2 and the lower mold 3 are opened, and the mounting part having the mounting seat 1 is taken out. At this time, the surface 14 of the convex portion 14 is perpendicular to the ceiling portion 13 . Since a is formed of a convex portion 20, the convex portion 14 does not undercut the movement of the slide core 4, and the slide core 4 can slide smoothly.

Further, the convex portion 14 will not be worn out or deformed.

Then, the nut 5 is inserted into the space surrounded by the pair of guide walls 11, the bottom wall 12, and the ceiling part 13 from one opening. At this time, the nut 5 is inserted while pressing the convex part 14 and elastically deforming the mounting seat 1. When the insertion is completed, the surface 14a of the convex part 14, the guide wall 11, and the bottom wall 12 come into contact with the end surface of the nut 5, and the nut 5 is inserted. 5 movement is restricted. As a result, the nut 5 is held on the mounting seat 1.

In this state, the part to be mounted is carried to the position to be mounted, and a bolt extending from the part to be mounted is inserted through the mounting hole 15 and screwed into the nut 5. As a result, the ceiling part 13 is held between the nut 5 and the part to be mounted, and the parts to be mounted can be mounted. In addition,
The tip of the bolt protruding from the nut 5 protrudes from the bolt hole 16.

(Other aspects of the embodiment) In the manufacturing method of the embodiment described above, the surface 14a that becomes the undercut of the convex portion 14 is formed in the convex portion 20 of the upper die.
The surface 14a can also be formed using the lower mold 3 as shown in FIG.

That is, by providing the lower convex portion 30 that protrudes from the lower mold 3 toward the upper mold 2, the surface 14a can be formed by the lower convex portion 30. Even in this case, it is possible to prevent the convex portion 14 from becoming an undercut, and the slide core 4 can be smoothly moved.

In this case, a hole is formed in the general surface 10 due to the downward convex part 30, but on the contrary, the size of the mounting hole 15 in the ceiling part 13 can be made smaller, so that the area of the ceiling part 13 can be increased. It is possible to increase the mounting strength.

Further, in the above embodiment, the convex portion 14 is provided on the ceiling portion 13, but even if it is provided so as to protrude from the general surface 10 toward the ceiling portion 13, undercuts can be similarly prevented. It may be provided on both the ceiling portion 13 and the general surface 10.

[Brief explanation of drawings]

Figures 1 to 5 relate to a manufacturing method of an embodiment of the present invention, in which Figure 1 is a perspective view of the formed mounting seat together with a nut, Figure 2 is a sectional view of the mounting seat, and Figure 3 is a sectional view of the mounting seat. 4 is a sectional view of the molding die, FIG. 4 is a sectional view taken along line AA in FIG. 3, and FIG. 5 is a sectional view taken along line BB in FIG. 4. FIG. 6 is a sectional view of a mold according to another aspect of the embodiment. FIG. 7 is a perspective view showing a mounting seat formed by a conventional manufacturing method together with a nut, and FIG. 8 is a cross-sectional view showing a state in which the mounting seat formed by a conventional manufacturing method is attached. 1... Mounting seat 4... Slide core] O... General surface 13... Ceiling part 15... Mounting hole 2... Upper die 3... Lower die 5... Oak 1~ (Fixing member> 11... Guide wall 14... Convex part

Claims (1)

[Claims] (1) A pair of guide walls protruding from the general surface of the mounting part to face each other, a ceiling part having a mounting hole and installed between the pair of guide walls, and at least one of the ceiling part and the general surface. A convex portion is provided and protrudes toward the other side of the general surface and the ceiling portion, and a fixing member such as a nut is accommodated in a space surrounded by the guide wall and the ceiling portion, and the convex portion protrudes toward the other side of the ceiling portion. A method for manufacturing a resin mounting seat that prevents a fixing member from falling out of the space, the method comprising using a pair of split molds and a slide core to form the convex portion with one of the split molds and the slide core. A method for manufacturing a resin mounting seat, characterized in that a surface of the convex portion that is an undercut with respect to the direction in which the slide core is pulled out is formed on at least one of the split molds.