JP2581116Y2 - Plastic bathtub mold - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic bathtub molding die, and more particularly to a plastic bathtub molding die reinforced with fibers.

[0002]

2. Description of the Related Art Plastic bathtubs are already widely used. In this case, as the plastic, an unsaturated polyester resin reinforced with fibers was preferred, and as the fibers, glass fibers were used. As this material, a sheet-like material (SMC) and a bulk-like material (BMC) were used. The temperature during molding is 145 ° C for SMC,
In the case of BMC, the standard was set to 125 ° C., and the allowable variation range of the temperature was set to ± 2 ° C. In order to form a bathtub using such a material, a bathtub forming die for integrally forming the entire bathtub from the beginning was required.

[0003] The bathtub forming mold is composed of a convex mold having a convex surface forming the inner surface of the bathtub and a concave mold having a concave surface forming the outer surface of the bathtub. The convex and concave molds were made such that when they were mated, they formed a tub-shaped gap just between them. Plastic reinforced with fiber
When heated in the mold, the resin melted and flowed, filling the gaps, and was pressed and cured as it was to form a bathtub. Therefore, in the bathtub mold,
It was necessary to provide a media path for heating the convex and concave surfaces.

In a bathtub forming mold, it is relatively easy to provide a medium passage in a concave mold, but it is relatively difficult to provide a medium passage in a convex mold. The reason will be described with reference to FIG. FIG. 1 shows a conventional bathtub molding die in cross section.

In FIG. 1, the concave mold 1 and the convex mold 2 are open. The concave mold 1 has a concave surface 11 forming the outer surface of the bathtub.
And a medium passage 12 surrounding the concave surface 11. The media passage 12 begins at the inlet 13 and continues through passages 14 and 15 extending along the bottom of the concave surface 11 to passages 16 and 17 extending along the side surface of the concave surface 11 and the outlet 1
Ends with 8. To make these passages 14, 15, 16 and 17 it is easy to form them by drilling holes from the outer surface of the concave mold 1, connecting the drilled holes to each other, and then closing the openings exposed on the outer surface. Can be. For example, in order to form the passage 14, after forming the passage 14 as a through hole, the passage 14 can be easily provided by closing the portion of the number 19.

The convex mold 2 has a convex surface 21 forming the inner surface of the bathtub, and has a medium passage 22 for heating the convex surface 21. The media passage 22 begins at the inlet 23 and continues through the passages 24 and 25 to the outlet 26. Medium passage 22
As can be seen from FIG. 1, the convex surface 2
The passage 2 extending from the base 27 of FIG.
Only 5, the passage extending parallel to the front end surface of the convex surface 21 is not formed. This is because it is not possible to create a passage extending parallel to the front end surface of the convex surface 21. The reason is that, in order to form a passage extending parallel to the tip surface of the convex surface 21, a hole must be made in the side surface of the convex surface 21, but if such a hole is made, it is necessary to fill the hole later by welding. , Pinholes occur during welding,
This is because even after-treatments such as grinder finishing and buff finishing may cause a fine uneven surface on the inner surface of the bathtub. Therefore, a passage extending parallel to the tip end surface of the convex surface 21 was not formed in the convex mold 2.

The medium passage 22 in the convex mold 2 is arranged as shown in FIG. 2 in a plan view. That is, the entrance 23
The medium that has entered through the inside of the base 27 is horizontally dispersed through the passage 24 provided therein, but inside the convex surface 21, it can travel through the passage 25 in a direction perpendicular to the front end surface of the convex surface 21. And it was. In addition, since the passage 25 was limited at the end, the medium was forced to pass through the same passage in both directions.

[0008] When a bathtub is formed, steam is usually used as a heating medium. When the water vapor is introduced into the convex-shaped medium passage 22, the water vapor condenses in the passage. For this reason, in a dead end passage such as the passage 25, the base 27 must be lowered so that the condensed water can be discharged downward. Therefore, conventionally, the convex mold 2 is positioned downward, and accordingly, the concave mold 1 is positioned upward,
The arrangement has been implemented as shown in FIG.

However, it is possible to avoid providing such a passage as the passage 25 which has a dead end. For example, this can be performed by hollowing out the inside of the convex mold 2, forming an annular passage at the boundary formed by hollowing out, and then filling the inside. However, doing so increases the cost of mold production due to the necessity of complicated processing, and is therefore not industrially feasible. Therefore, a bathtub has been actually made using a mold as shown in FIG.

When a bathtub is made by the method shown in FIG. 1, the bathtub is in a state where the bottom is up and the opening is down. It is necessary that the bathtub be released from the convex by an air knock after the completion of molding, and then removed from the press. At this time, both the mold and the bath are heated to about 125 ° C. or 145 ° C., and therefore, the release and the removal are performed at a high temperature. Moreover, the surface of the bathtub must not be damaged during this operation. Therefore, a large-scale suction-type device is required for removal.
In addition, it is necessary to provide a drain port at the bottom of the bathtub, and it is necessary to check the inner surface. Therefore, a large reversing device is required. In addition, in the method of FIG. 1, when the mold is opened, the convex surface 21 faces upward, so that another object falls or comes into contact with the convex surface 21 to easily damage the convex surface 21. Therefore, a scratch is generated on the inner surface of the bathtub. There was a fear. In addition, in the method of FIG. 1, since the convex surface 21 faces upward, dust easily accumulates on the convex surface 21 during molding, and the accumulated dust appears on the inner surface of the bath tub. The workplace was surrounded by vinyl and work was done inside. Therefore, it was necessary to improve these points.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to improve the above-mentioned drawbacks. That is,
This invention allows the molded bathtub to be removed from the mold by placing the convex mold on the upper side and the concave mold on the lower side so that the bottom of the bathtub can be lifted and moved laterally to be taken out. It seeks to eliminate the use of suction-type removal devices, reversing devices, and vinyl enclosures.

[0012]

As in the prior art, when the convex mold is located above and the concave mold is located below, water vapor condenses in the medium passage in the convex mold, and the condensed water is confined to the endless passage 2.
5, the convex surface becomes lower than the concave surface by about 15 ° C. because of hot water heating, and it was difficult to maintain the temperature of each part within the set temperature ± 2 ° C.
The inventor has found that this inconvenience can be solved by improving the passage 25.

The idea of the present invention is to use a V-shaped crossing of a forward passage and a return passage instead of the conventional dead end passage 25 in the convex mold 2. That is, the passage 25 is divided into two obliquely straight passages, and the two straight passages are connected so as to intersect in a V-shape near the front end surface of the convex surface 21 to facilitate the passage of the medium. ,
The main point is that the condensed medium is improved so that it does not stay in the passage.

According to the present invention, a mold for forming a bathtub is constituted by a convex mold having a convex surface forming the inner surface of the bathtub and a concave mold having a concave surface forming the outer surface of the bathtub. Are provided with passages for the heating medium, respectively, but this point is the same as the conventional bathtub molding die.
Further, in the present invention, the medium passage provided inside the concave shape is provided similarly to the conventional one. However, in the present invention, the medium passage inside the convex surface in the convex shape is changed to the one crossing in a V-shape as described above, which is greatly different from the conventional convex shape.

In this invention, the medium passage provided in the convex surface is constituted by a large number of linear passages extending linearly from the base of the convex shape to near the tip of the convex surface. The ends of the paired straight passages intersect in a V-shape near the convex surface, and each of the paired V-shaped passages is connected to a horizontal passage passing through the convex base.
To form a medium passage in the convex shape . This invention is characterized in that the dead paths in the convex surface are eliminated, and these paths are formed as a series. Further, the invention is characterized in that the convex shape is positioned upward and the concave shape is positioned downward so that the medium can be smoothly passed through the passage.

An example of the present invention will be described below with reference to the accompanying drawings. FIG. 3 is a cross-sectional view of the bathtub forming mold according to the present invention. In FIG. 3, the mold is opened as in FIG. Compared to the mold of FIG. 1, the mold of FIG. 3 has a point where the convex mold 1 is located above and the vertical relationship is inverted, and a passage 25 which enters the convex surface intersects in a V-shape. The only difference is that the two passages 28 and 29 are replaced. In FIG. 3, parts corresponding to each other are denoted by the same reference numerals for convenience of comparison with FIG.

The convex mold 2 shown in FIG. 3 has a convex surface 21 forming the inner surface of the bathtub and has a medium passage 22 for heating or cooling the convex surface 21. In this respect, the conventional mold shown in FIG. Same as the ones. The passage 22 is the same as the conventional one, starting from the inlet 23 and passing through the passage 24.
However, this is different from the conventional one in that the passage 24 is connected to a V-shaped passage that enters the inside of the convex surface 21 at some point on the way. More specifically, the passage 28 and the passage 2
Reference numeral 9 denotes a pair of straight passages, which cross each other at a tip end 30 and communicate with each other, and have a V-shaped overall. In other words, in the conventional convex type, one straight passage 25 at a dead end is replaced by two V-shaped straight passages 2 intersecting at corresponding positions.
8 and 29. In this respect, the mold according to the present invention is significantly different from the conventional mold.

FIG. 4 is a bottom view when the convex mold 2 is viewed from below in the mold of FIG. In FIG. 4, the passage 24 is formed in the convex base 27, but the passage 24 is bent and advanced, starting from the inlet 23 and ending at the outlet 26. Moreover, the passage 24 has a convex surface 21 in some places.
Are connected to the straight passages 28 and 29 entering the inside. The passages 28 and 29 form a pair and intersect at the leading end, and have a V-shape as a whole.

The convex mold 2 as shown in FIG. 3 is easy to manufacture. That is, since the passage 24 is formed in the base 27, it is easy to attach the passage 24 as in the conventional mold. Since the passages 28 and 29 are straight passages like the conventional passage 25, it is easy to add them. However, the passages 28 and 29 are different from the conventional passage 25 in that they need to intersect in a V-shape at the tip, but such an intersection can be easily achieved by a special drilling machine of numerical control. Therefore, the mold of the present invention is easy to manufacture as in the conventional mold.

3, the concave mold 1 is different from that of FIG. 1 only in that it is turned upside down, and in other respects there is no change. That is, the concave mold 1 has a concave surface 11 forming the outer surface of the bathtub and has a medium passage 12 surrounding the concave surface 11, but in these respects, the concave mold 1 of FIG. 3 is the same as the concave mold 1 of FIG.

As shown in FIG. 3, the mold according to the present invention can be used with the convex mold 2 on the upper side and the concave mold 1 on the lower side. At this time, even if steam is introduced into the medium passage to heat the mold, a situation in which the condensed steam stagnates in the mold and heating is prevented does not occur. In other words, until now, the convex mold 2 is positioned on the upper side and the medium passage 22
When water vapor is introduced into the inside, water condensed in the dead end passage 25 stagnates, but the dead end passage is lost,
Instead, the passages 28 and 29 which intersect in a V-shape are formed, so that the condensed water does not stagnate, so that the steam can smoothly pass therethrough, and the convex mold 2 can be heated without any trouble. Can be reliably maintained within a narrow temperature range of ± 2 ° C. of set temperature. In addition, condensed water in the passage for some reason
Is stagnant, for example, attached to the exit 26 in FIG.
Open or enter a steam trap (not shown)
Easily remove condensed water by sending pressurized air from 23
can do. Therefore, in any case,
The convex shape can be heated as desired by passing steam smoothly
The mold temperature within a small margin of error from the set temperature.
I can stop.

[0022]

According to the invention, the passage of the heating medium in the convex is formed by a large number of straight passages extending linearly from the base of the convex to near the tip of the convex. It is easy to manufacture a convex shape. In addition, the above-mentioned straight passages are paired two by two, and the ends thereof are crossed in a V-shape inside the convex surface, and each V-shaped straight passage is connected to a horizontal passage penetrating the convex base. As a result, when the steam is introduced into the medium passage, the condensed water does not stagnate in the passage even when the steam is condensed. can do. For this purpose, a mold is installed with the convex mold positioned above and the concave mold positioned below, and the bathtub can be formed in this state. Therefore, the bottom of the molded bathtub is located at the bottom, and the opening faces upward.Therefore, there is no need to turn over the bathtub after releasing the mold and taking it out. It can be inspected and stored as is. Therefore, a reversing device is not required, and the bathtub can be easily formed. Also, neither a suction type take-out device nor a vinyl enclosure is required, and the bathtub can be easily formed. Furthermore, since this mold has a convex surface facing downward and a concave surface facing upward, there is little risk of damaging the convex surface,
Therefore, it is possible to surely make a bathtub without any damage. The present invention provides such benefits.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a conventional plastic bathtub forming mold.

FIG. 2 is a plan view of a convex mold of the mold shown in FIG.

FIG. 3 is a longitudinal sectional view of a plastic bathtub forming mold according to the present invention.

FIG. 4 is a bottom view of a protrusion of the mold shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Concave type 2 Convex type 11 Concave surface 12 Medium passage 13 Inlet 14 Passage 15 Passage 16 Passage 17 Passage 18 Exit 19 Blocking part 21 Convex surface 22 Medium passage 23 Inlet 24 Passage 25 Passage 26 Exit 27 Base 28 Straight passage 29 Straight passage 30 Front end

Claims (1)

(57) [Scope of request for utility model registration] 1. A convex type having a convex surface forming an inner surface of a bathtub and a concave type having a concave surface forming an outer surface of a bathtub, and a passage of a heating medium is provided inside each of the convex type and the concave type. In a plastic bathtub forming mold, a convex mold is positioned upward and a concave mold is positioned downward, and a plurality of media passages extending straight from the base of the convex mold to near the tip of the convex surface in the convex mold. constituted by a straight passage, the distal end inside the convex surface causes cross in a V-shape, each V-shaped straight path that paired the base transmural in pairs a straight path two by two
A plastic bath tub forming die connected to a horizontal passage through which the medium passage in the convex mold is formed.