JPH0525648B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a foam molding method, particularly a foam molding method suitable for use in molding seat backs of vehicle seats, and relates to a foam molding method suitable for use in molding seat backs of vehicle seats. In addition to improving the appearance of the seat bag, the front side portion and the back side portion of the seat bag can be molded with different types of foam materials.

(Prior Art) As a conventionally known foam molding method of this type, for example, there is one previously disclosed by the applicant in Japanese Patent Application Laid-Open No. 60-240414 (Japanese Patent Application No. 59-95749).

This includes a fixed mold and a movable mold that rotates relative to the fixed mold and forms a cavity in cooperation with the fixed mold, and a back forming member located in the center of the movable mold. A core member that forms an inward flange of the foam product is provided around the foam product, and at least a portion of the core member is rotatable in the vertical direction. The foaming stock solution is injected into the mold, and then the movable mold is rotated relative to the fixed mold to close the mold and both molds are maintained in a horizontal position, so that the foaming stock solution is poured into the back side of the core member. A foamed product having an inward flange on the back side is produced by foaming and fluidizing the foam to the point where the foamed product has an inward flange on the back side.

(Problem to be Solved by the Invention) However, in this prior art, since the foaming solution injected into the fixed mold is foamed and flowed to the back side of the core member, the inside of the core member is foamed and flowed. The inward flange formed by the action of the child member, and by extension, the back side of the foamed product, has flow marks due to the long foaming flow distance of the foaming stock solution, which deteriorates the appearance of the foamed product. In addition to the problem, the front side part and the back side part of the foamed product have different characteristics (physical properties specified in JASO-B408 and physical properties caused by the combination of hot cure foam and cold cure foam). ) There was a problem in that it was virtually impossible to construct the foam from two different types of foam materials.

The present invention advantageously solves the problems of the prior art, significantly improves the appearance of the back side of a foamed product, and allows the front side and back side of the foamed product to be separated into different types. The object of the present invention is to provide a foam molding method that makes it possible to construct a foam material.

(Means for Solving the Problems) The method of the present invention includes a front mold for molding the front side portion of a foamed product, a back mold for molding the back side portion thereof, and a mold that is formed independently of these molds. When molding is performed using a foaming mold consisting of a core inserted between the molds, a foaming stock solution is injected or sprayed into the molding surfaces of the front mold and back mold, which are opened almost horizontally. Preferably, the front mold and the back mold are closed with the core sandwiched between them at a timing of 30 to 100% of the rise time of the foaming stock solution.

Here, the rise time means the time from the end of the injection or spraying operation of the foaming stock solution until the foaming of the foaming stock solution that was last injected or sprayed is completed.

Another method of the present invention is to inject or spray a foaming stock solution onto the molding surface of either the front mold or the back mold in a substantially horizontal position.
Layer the core on one of the molds, then inject or spray the foaming solution onto the core, then overlap one mold with the other mold, close the mold, and then place both molds on a horizontal surface. This is to maintain a posture facing upward.

In still another method of the present invention, a foaming stock solution is injected or sprayed onto the molding surface of one of the molds in an approximately horizontal position, and after the core is stacked on the mold, this is also approximately A foaming solution is injected or sprayed onto the molding surface of the other mold in a horizontal position, then both molds are closed, and both molds are maintained in a position facing upwards from the horizontal plane. . Here, both molds can be closed by rotating each mold together relative to the horizontal plane, or by first injecting or spraying the foaming stock solution into the mold, and then injecting the foaming stock solution later. Alternatively, it can also be carried out in a state where it is superimposed on a sprayed mold.

Furthermore, in each of the above-mentioned methods, the foaming stock solution injected or sprayed onto the molding surface of one mold and the foaming stock solution injected or sprayed onto the molding surface or core of the other mold are of the same type. It can be made into one thing, and it can also be made into a different kind of thing.

(Function) According to each of the above-mentioned methods, the foaming stock solution for forming the front side portion and the foaming stock solution for forming the back side portion of the foamed product are placed on the molding surface or core of each mold, respectively. Since it is injected or sprayed separately, the flow length of the foaming stock solution for forming each part of the foamed product is made sufficiently small, and the molding surface of the foamed product, especially the back side part, is made extremely smooth. As a result, the appearance of the foamed product is greatly improved.

Moreover, in each of these methods,
Since the foaming stock solution for forming the front side part and the foaming stock solution for forming the back side part are separately injected or sprayed, each of the foaming stock solutions can be of a different type. It becomes possible to construct a foamed product using two types of foamed materials with different properties, and it is possible to impart desired physical properties to each part of the foamed product.

(Example) Examples of the present invention will be described below based on the drawings.

FIG. 1 is a perspective view illustrating a foam mold that can be used to carry out the present invention.

This foaming mold is for molding a seat bag for an automobile seat as shown in a perspective view in FIG.
The SB has a relatively soft main pad M located on the front side and forming the back rest, and a space on the back side for inserting the seat back frame into the back side of the main pad M. It consists of a relatively hard safety pad S that divides the area.

For this reason, the foam molding die shown in the figure consists of a front mold 1 for molding the main pad M and a safety pad S.
and a back mold 2 forming the outer surface contour of the safety pad S, and an inward flange portion S _f of the safety pad S.
It is equipped with a core 3 for forming.

Therefore, as shown in the figure, the front mold 1 is
The ends of the back mold 2 that contribute to the formation of the upper end portion of the seat bag SB are interconnected via a bracket, and a portal frame 6 positioned straddling the connection is attached to both ends of the pivot shaft 5. One end of the core 3 is pivotally supported by a shaft 7 provided on the portal frame 6 and extending horizontally at an appropriate position.

Reference numeral 8 in the figure indicates a support rod that adjusts the tilting angle of the portal frame 6 with respect to the base 4. It is also possible to change to a ratchet mechanism or other suitable support means.

Preferably, a gate 9 communicating with the molding surface is provided at the free end of one of the molds, the rear mold 2 in the figure.
a, and by opening and closing this gate 9a with a lid member 9b pivoted on a shaft 7 provided on the gate-shaped frame 6, gas can be vented as required from there, and in some cases, It is also possible to inject foamed materials.

Also preferably, a protrusion 10 for forming a through hole in the main pad M is provided on the front surface of the core 3 facing the front mold 1. In addition, these protrusions 1
0 can also be used as a positioning means for a spring receiving material embedded in the main pad M, such as coarse wool felt or cheesecloth.

In foam molding using the molds described above, a mold release agent is applied to the molding surfaces of each mold 1 and 2 in advance, and the molds 1 and 2 are kept at a temperature within a predetermined range (so-called hot temperature). For Tokiyu type polyurethane foam, for example, 30 to 40
For cold cure type polyurethane foam, molds 1 and 2 are cooled or heated to, for example, 50 to 65 degrees Celsius.
is opened almost horizontally as shown in FIG. 1, and foaming stock solutions 11 and 12 of the same or different type are poured onto the respective molding surfaces of both molds 1 and 2, as shown in the cross-sectional view in FIG. are injected or sprayed almost simultaneously or in the required order, preferably from 30 to the rise time of the foaming stock solutions 11 and 12.
At 100% timing, the front mold 1 and the back mold 2 are closed with the core 3 sandwiched therebetween by the action of the clamping fittings 13.

Here, this mold closing can be performed with each of the front mold 1 and the back mold 2 standing upright as shown in FIG. This can also be carried out in a state in which the molds are successively stacked one on top of the other. In such a mold closed state, the gas generated due to foaming of the foaming stock solutions 11 and 12 can be discharged by a gas (not shown) provided in at least one of the molds. This is done through a punch hole and/or a gate 9a. In this case, when the gate 9a is opened to discharge the gas, the filling rate is increased just before the foaming stock solution starts to overflow from there.
When it reaches 95-99%, the gate 9a is closed by the lid member 9b.

Thereafter, both dies 1 and 2 are maintained in a horizontal position or in a required position facing upward from the horizontal plane to cure the form. By the way, to cure the foam, if the polyurethane foam is of the hot cure type, the mold is often heated at a temperature of 160 to 230°C for 10 to 15 minutes, and also cold cured. If it is your type, it is also often heated at a temperature of 50 to 80 degrees Celsius.
Heat for ~8 minutes.

After forming the seat bag in this way,
The mold is cooled as required, the front mold 1 and the back mold 2 are opened as shown in Fig. 5, and finally, the sheet bag SB remaining on the core is removed from the core 3. , around axis 7, the sixth
The series of operations is completed by pulling it out from the core 3 in the rotational posture shown in the figure or in the rotational posture in the opposite direction to that shown in FIG.

According to this method, the foaming stock solution 11 for forming the main pad and the foaming stock solution 12 for forming the safety pad of the seat bag SB are separately injected or sprayed onto the molding surfaces of the respective molds 1 and 2. Therefore, the required flow length of the foaming stock solution can be made sufficiently small, and therefore, the flow traces of the foaming stock solution can be completely removed from the molded surface of the seat bag SB, especially its safety pad, and the appearance of the safety pad S can be improved. In addition to greatly improving the appearance, it is also possible to reduce the internal pressure of the mold and effectively prevent the occurrence of defects such as cracks and voids.

In addition, in this method, each foaming stock solution 1
If 1 and 12 are of different types,
The main pad M and the safety pad S can each be made of two types of foamed materials with different properties, and each of them, and by extension the seat back SB, can be given desired physical properties.

Therefore, after covering the seat bag SB with a woven fabric or other so-called skin material, it is possible to advantageously improve the appearance, especially from the back side.

Furthermore, with this method, the foaming stock solutions 11 and 12 can be simultaneously injected or sprayed into the respective molds 1 and 2, so the time from the start of injection or spraying to its completion can be sufficiently shortened. The length of the production line can also be effectively shortened.

In addition, here, foaming stock solution 1 is applied to both molds 1 and 2.
By immediately closing both molds with the core in between after pouring or spraying Nos. 1 and 12, the process up to the end of mold closing can be significantly simplified.

Furthermore, when the gas generated due to the foaming of the foaming stock solutions 11 and 12 is discharged through the gate 9a, it is possible to significantly reduce the amount of stem marks and vent waste generated at positions corresponding to gas vent holes (not shown), and also to reduce the amount of sheet backing. A reduction in the weight of the SB can be effectively prevented.

Here, the mold closing as described above is carried out at 30 to 30 of the rise time of each foaming stock solution 11 and 12.
Especially if you do it with 100% timing.
When the respective foaming stock solutions 11 and 12 are of different types, the boundary portions of the respective foaming materials can be smoothly changed.

In addition, in the foam molding according to another method of the present invention, on the molding surface of either the front mold 1 or the back mold 2 held in a substantially horizontal position, as shown in FIG. After injecting or spraying the foaming stock solution 11, the core 3 supported via the shaft 7 is superimposed on the front mold 1 on the gate-shaped frame 6 which is laid down on the front mold side, and then the core 3 is placed on the front mold 1. Then, the foaming stock solution 12 is injected or sprayed as shown in FIG. 8, and then the front mold 1 and the back mold 2 are placed on top of each other as shown in the cross-sectional view in FIG. 9, and both molds are closed. After that, both molds 1 and 2 are placed in a position facing upward from the horizontal plane,
For example, this may be done by curing the form while maintaining it in a vertical position as shown in FIG.

In addition, in this method also, after closing the mold,
The generated gas is discharged in the same manner as described above via a gas vent hole and/or gate 9a (not shown).

According to this method, the foaming stock solution 12 is injected or sprayed onto the molding surface of the back mold 2 as the other mold, and the core 3 and the front mold 1 are sequentially stacked on the back mold 2. is also possible.

In this molding method, each foaming stock solution 1
1 and 12 are separately injected or sprayed onto the molding surface and onto the core, so as in the above-mentioned example, flow traces of the foaming stock solution are removed and the appearance of the Safety Pad S and, ultimately, the Seat Back SB is greatly improved. In addition, each part of the seat bag SB can be made of foam material with characteristics according to requirements.

Furthermore, here, since the foaming stock solutions 11 and 12 can be injected or sprayed only on one side of the shaft 5, one or two foaming machines are disposed only on one side of the shaft 5. By this,
The space occupied by the device can be advantageously reduced.

Furthermore, in this method, the foaming solution is not supplied to the overlapping mold of both molds 1 and 2, so leakage of the foaming solution when closing the front mold 1 and back mold 2 is completely prevented. can do.

Moreover, according to this method, after the molds 1 and 2 are closed, the form is cured while maintaining them in a position facing upward from the horizontal plane. Compared to the conventional technology that cures the foam, it is possible to significantly reduce the occurrence of burrs between the mating surfaces of the mold, and it also makes it possible to extremely smoothly discharge the gas generated by foaming to the outside of the mold. Product defects caused by gas retention in the vicinity of the mating surfaces 1 and 2 can be almost completely eliminated.

In still another molding method of the present invention, first, either the front mold 1 or the back mold 2 is placed in a substantially horizontal position, and as shown in a schematic side view in FIG. The foaming stock solution 12 is injected or sprayed onto the molding surface of the mold 2, and then the core 3 is superimposed on the back surface of the mold as shown in FIG. Foaming stock solution 1 is placed on the molding surface of the front mold 1.
1 is injected or sprayed, and when the foaming status of each foaming stock solution 11 and 12 reaches 50 to 100% of the rise time,
Or, at a timing of 100% or more of the rise time of the foaming stock solution 12 supplied earlier and less than the tack free time, and at a timing of 50 to 100% of the rise time of the foaming stock solution 11 supplied later, Both molds 1 and 2 in appropriate postures, Fig. 10c
As shown in Figure 1, each mold 1 and 2 are closed in an upright position, and then both molds 1 and 2 are maintained in a position facing upwards from the horizontal plane to cure the form. .

Note that in this method, the front mold 1 as the other mold is
The foaming stock solution 11 is first supplied to the front mold 1, and the core 3 is superimposed on the front mold 1, and then the foaming stock solution 1 is supplied to the back mold 2.
It is also possible to supply 2.

This method also achieves the same effects as each of the above-mentioned embodiments, namely, improving the appearance of the seat bag SB and improving the appearance of each part of the seat bag.
A structure made of a foamed material having properties according to requirements can be realized.

Moreover, in the illustrated method, since the core 3 is superimposed on the back mold 2 to which the foaming stock solution 12 has been supplied, the core 3 functions as an inner lid, making it easy to control the thickness of the safety pad S. .

By the way, in addition to overlapping the core 3 on the back mold 2, when closing both molds 1 and 2 at a timing of 50 to 100% of the rise time of the respective foaming stock solutions 11 and 12, The interface between the main pad M and the safety pad S can be easily controlled.
2, at a timing of 100% or more of the rise time and less than the tack free time, and 50 to 100% of the rise time of the foaming stock solution 11 supplied later.
This is especially noticeable when closing the mold at the timing of .

Another molding method of the present invention, which is different from the above, includes supplying the foaming stock solution 12 to the back mold 2 and superimposing the core 3 on the back mold 2, as shown in FIGS. 10a and 10b. After sequentially supplying the foaming stock solution 11 to the front mold 1, the core 3 and the back type 2, as shown in FIG. 10d,
The mold is superimposed on the front mold 1 and the mold is closed, and then both molds 1 and 2 are maintained in a posture facing upward from a horizontal plane to cure the form.

According to this method, not only can the effects common to each of the above-mentioned embodiments be brought about, but also the thickness of the safety pad S and the interface between the main pad M and the safety pad S can be controlled extremely easily. At the same time, it is possible to almost completely prevent leakage of the foaming stock solution when closing the mold.

The present invention has been described above using the mold shown in FIG. 1, but as shown in FIG. Either end portion of the front mold 1 and the rear mold 2, preferably as shown,
The respective ends contributing to the molding of the lower end portion of the seat bag are interconnected via a bracket, and between the molds, one end of the core 3 is connected to the pivot 5, also via a bracket. It can also be carried out by means of a mold pivoted by the front mold 1 and the rear mold 2, with the front mold 1 and the rear mold 2 interconnected by a pivot 5, and the formation of either of the molds separated from the pivot. This can also be achieved by directly pivoting the core 3 on the end.

FIG. 12 is a perspective view showing another example of the mold shown in FIG. 11, in which a through hole 14 having a desired shape and dimensions is provided in the central portion of the core 3 or in its vicinity. Along with the rear type 2
A protrusion 15 that fits into the through hole and seals it is provided, and the tip surface of the protrusion 15 is smoothly continuous with the molding surface of the core 3 while it is fitted into the through hole 14. This is a molding surface part that contributes to the molding of foamed products.

According to this mold, with the front mold 1 in a horizontal position as shown, the core 3 is placed on the front mold in advance as shown in FIG. 13 based on its own rotational movement. Then, the foaming source liquid is supplied onto the front mold through the core through hole 14 as shown in FIG. 14, and the foaming source liquid is supplied onto the core as shown in FIG. By performing these steps in sequence, and then closing the mold and subsequently curing the foam in the desired position of the mold, the desired foamed product can be obtained, as well as the core. It is also possible to carry out foam molding by supplying a foaming source liquid onto the top of the mold and then supplying the same or different type of foaming source liquid onto the front mold. Seat bag SB with inward flange parts S _f in four directions as shown in FIG.
However, regardless of whether or not the material of the main pad M and the material of the safety pad S are the same, the molding can be performed without any molding defects occurring on the outer surface.

Although the foam molding of seat bags has been described above, the present invention can of course be applied to the molding of various other foam products by changing the molding surface of the mold as necessary.

(Effects of the Invention) According to the present invention, in particular, the foaming stock solution for forming the front side portion and the foaming stock solution for forming the back side portion of the foamed product are applied to the molding surface or inside of each mold. By separately injecting or spraying each part onto the foamed product, the flow length of the foaming stock solution for forming each part of the foamed product is made sufficiently small, and the forming surface of each part is smoothed, and the overall quality of the foamed product is improved. In addition to providing an improved appearance, the foaming pressure can be advantageously reduced to effectively prevent the occurrence of cracks, voids, etc., as well as the occurrence of burrs.

Furthermore, in this invention, if the foaming stock solutions supplied separately are of different types, the foamed product can be composed of two types of foamed materials with different characteristics, and the foamed product can be It is possible to impart desired physical properties to each part.

Furthermore, in this method, the form is cured while the mold is kept in a position facing upward from the horizontal plane after the mold has been closed. In comparison, the generation of burrs between the mating surfaces of the molds can be significantly reduced, and the gas generated by the foaming of the foaming stock solution can be smoothly discharged outside the mold, and the gas generated in the vicinity of the mating surfaces of both molds can be smoothly discharged. Product defects caused by lingering gas can be almost completely eliminated.

[Brief explanation of the drawing]

Fig. 1 is a perspective view illustrating a foam mold used in carrying out the present invention, Fig. 2 is a perspective view illustrating a seat bag as an example of a foam product, and Figs.
Figures 7 to 9 and 10 are diagrams illustrating the implementation steps of this invention, and Figures 11 and 12 are perspective views illustrating other foam molds that can be used to implement this invention, respectively. , FIGS. 13 to 15 are perspective views illustrating a molding process using the mold shown in FIG. 12, and FIG. 16 is a perspective view showing a seat bag molded by the mold shown in FIG. 12. It is. 1... Front type, 2... Back type, 3... Core, 1
1,12...Foaming stock solution, SB...Sheet bag,
M...Main pad, S...Safety pad, S _f
...Inward flange part.

Claims (1)

[Claims] 1. A front mold for molding the front side portion of a foamed product;
When molding is performed using a foam mold consisting of a back mold for molding the back side of the foam and a core inserted between these two molds, the front mold and back mold are each opened almost horizontally. A foam molding method characterized by injecting or spraying a foaming solution onto the molding surface of the mold, and then closing the front and back molds with a core sandwiched between them. 2. A front mold for molding the front side part of the foamed product;
When molding is performed using a foam mold consisting of a back mold for molding the back side of the foam and a core inserted between these two molds, the front mold or back mold is held in an almost horizontal position. After injecting or spraying the foaming solution onto the molding surface of one of the molds, stack the core on one of the molds, then injecting or spraying the foaming solution onto the core, and then A foam molding method characterized by stacking another mold, closing the mold, and maintaining both molds in a position facing upward from a horizontal plane. 3. A front mold for molding the front side part of the foamed product;
When molding is performed using a foam mold consisting of a back mold for molding the back side of the foam and a core inserted between these two molds, the front mold or back mold is held in an almost horizontal position. After injecting or spraying the foaming solution onto the molding surface of one of the molds, stack the core on one of the molds, then apply the foaming solution onto the molding surface of the other mold, which is also held in a nearly horizontal position. Inject or spray, then close both molds and
A foam molding method characterized by maintaining both molds in positions facing upward from a horizontal plane. 4.Claim 3: The front mold and the back mold are closed with the one mold superimposed on the other mold.
Foam molding method described. 5. The foaming stock solution injected or sprayed onto the molding surface of one mold and the foaming stock solution injected or sprayed onto the molding surface or core of the other mold are of different types. The foam molding method according to any one of the above.