JP3188344B2 - Foam molding method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foam molding method and apparatus which can flexibly cope with high-mix low-volume production. It is used in the industrial field of producing foam molded articles from urethane foam raw materials and the like.

[0002]

2. Description of the Related Art In the production of foam molded products, as in other manufacturing industries, there are cases where it is required to produce various types of parts in small quantities depending on the application. In such a case, it is unreasonable to apply a mass production device. For this reason, the following method has conventionally been used.

First, a simple mold 9 that can be handled by hand is manufactured in consideration of handling (FIG. 7). On the upper surface of the upper mold, a gas outlet 911 is provided near the upper side in the longitudinal direction, and an inlet 912 is provided near the lower side. Then, the simple mold 9 is held in one hand, the injection nozzle 92 is grasped with the other hand, and the foam molding material is injected into the cavity from the injection port 912 positioned below (FIG. 8). This is because air in the cavity and gas generated in the initial stage of foam molding are easily released. In this way, necessary raw materials are filled while being careful not to overflow the raw materials from the gas outlet 911 located above. The amount of injection is adjusted by a skilled worker in consideration of the raw material state at the time of injection. After the injection is completed, the simple mold 9 is turned down with the gas outlet 911 and the injection port 912 facing upward (FIG. 9). In this state, foam hardening proceeds. After completion of the foaming and curing, the upper mold 91 is opened to obtain a desired molded product.

[0004]

However, the conventional method has the following disadvantages. That is, until now, there has been no manufacturing method of standing or laying the whole mold by mechanical operation, as described above, because it relied on the movement of human hands,
The operation was slow. Until the final processing was completed for one simple model, the next simple model could not be worked on, and the production was completed one by one. Therefore, it took time and did not go back. In addition, human naval tactics were inefficient and product costs were high. Further, the simple type has to be large enough to be handled by a human hand, and its capacity is limited. For this reason, according to the above-mentioned method, a large foam molded article could not be produced.

[0005] Furthermore, since the skill of each skilled worker is relied on, the quality of the work varies. Even with the same worker, the quality of the finished product was not stable because the simple type had unevenness in the standing condition, the falling condition, the injection amount, and the like. In addition, the raw material often drops from the gas outlet 911 due to misunderstanding, and not only material loss but also the surrounding contamination of the dripped raw material has become a problem. When this was a urethane foam material or the like, it had an adhesive force and was difficult to clean and remove.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and eliminates the restriction on the size of a product to be produced. And an apparatus.

[0007]

According to the foam molding method of the first invention, a plurality of molding dies having a gas outlet and an injection port penetrating into a cavity are provided. The first operation of raising the mold by sequentially (a) arranging the gas outlet at the upper position on the side and the inlet at the lower position, (b) cavity from the inlet of the mold by an automatic injector. A second operation for filling a predetermined amount of foam molding raw material, and a third operation for tilting the mold so that the gas outlet and the injection port face upward.

[0008] Here, the "vertical length" means that the vertical length is equal to or longer than the lengths of the other sides. For example,
In the case of a rectangular body, it is sufficient that the vertical length is equal to or greater than the horizontal and depth lengths. “Side” refers to either the front or the left or right side wall in a state where the vertically long mold is erected. "Erecting the mold" includes, in addition to bringing the mold upright, here also includes a state of being inclined. Although it is inferior to the upright state, even when inclined, good results can be obtained in purging air existing in the cavity. “To fill the cavity with a predetermined amount of the foaming raw material” means to finish injecting the amount of the foaming raw material that forms the product part into the cavity. Therefore, when the injection is completed, it is necessary to ensure that the mold (a) stands upright. However, at the start of the injection, it is desirable that the mold is upright, but it is not necessary to do so.
For example, the requirement is satisfied when the mold is erected simultaneously with the injection of the foam molding material. The number of “injection ports” corresponds to the number of injection nozzles, and is usually limited to one. "Gas outlet"
Does not matter how many.

The foam molding apparatus according to the second aspect of the present invention has a molding die (1) in which a desired cavity is formed, and a gas outlet and an injection port penetrating into the cavity are provided on the side surface. In a state where the mold is erected so that the injection port is arranged at the outlet and the lower position, a base (21) for supporting the mold, and a back (abutting on the base and abutting against the rear surface of the mold). 22), and further comprising: a holder (2) having a back portion rotatable around a joint between the base portion and the back portion so that the back portion can be turned upside down, and placed on the holder in an upright state. After filling the cavity with the raw material for foam molding by the automatic injection machine from the injection port of the mold, the holder is turned down so that the gas outlet and the injection port face upward.

[0010] Here, the "joining portion" means a portion where the base portion and the back portion are attached to each other, and includes a region near the joining portion. The “mold” includes not only the mold body but also accessories such as a mold palette fixed to the mold body so as to be easily held by the holder.

[0011]

According to the foam molding method and apparatus of the present invention,
Since the production machine manufactures the foam molded article in response to the command instead of the human hand, the quality and reliability of the product are improved. Here, first, the vertically long mold is erected, and the gas outlet is arranged at the upper position on the side surface of the mold and the injection port is arranged at the lower position. Next, the foam molding raw material is poured into the cavity from the injection port of the molding die. Then, in the case where the vertically elongated mold was laid down, the air in the cavity was entrained, or the foaming gas was hindered by the drift of the raw material, so that gas accumulation was easily formed in the cavity, By standing up, the air in the mold and the unnecessary gas generated in the initial stage of the foam molding can smoothly escape from the upper gas vent without such a problem. On the other hand, since the foaming molding material is injected by the automatic injection machine, the cavity is reliably filled with a predetermined amount without overflowing the material from the gas outlet.

After injection of a predetermined amount by the automatic injection machine, the mold is turned down so that the gas outlet and the injection port face upward. In this way, even when the automatic injection machine is separated from the injection port, the foam molding raw material no longer spills. When each mold is sequentially fed into the automation process line that performs the above-described series of operations, a product of a constant quality can be obtained and the production efficiency can be improved. Then, if the shape of the cavity of each mold is made different according to the demand, it is possible to easily cope with high-mix low-volume production without difficulty.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments. (1) Configuration of Foam Molding Apparatus FIGS. 1 to 6 show one embodiment of a foam molding apparatus according to the present invention. A plurality of molds 1, 1,..., A holder 2, an automatic injecting machine 3, a holding lid 4, and air cylinders 51, 52, 5
3, 54, 55, the conveyor 6, and the curing furnace 71.

The molding die 1 is a vertically elongated rectangular parallelepiped as shown in FIG. 6, and has a two-part structure including an upper die 11 and a lower die 12. A desired cavity is formed inside. This mold 1
When the gasket is in an upright state, two gas outlets 111 and 111 are provided near the upper side of the upper mold, and one injection port 11 is provided near the lower side.
2 (FIG. 1). Gas outlet 111, injection port 112
Leads to the cavity. A plate-shaped pallet 13 is fixed to the back surface of the mold 1. The pallet 13 extends further up and down from the vertically long mold 1 to form a flange 131 (FIG. 6). The upper mold 11 is attached to a lower mold 12 by a hinge 14 so as to be freely opened and closed. Reference numeral 15 indicates a fixing tool for fixing the upper mold 11.

Reference numeral 2 denotes a base 21 formed by processing a long member.
And a holder comprising a long plate-shaped back portion 22 (FIG. 4). The base 21 receives the bottom surface of the standing mold 1,
The mold 1 is held. And the back part 22 supports the molding die 1 more reliably by being attached to the base part 21. The pallet 13 is provided so as to be in contact therewith. The back portion 22 is perpendicular to the base portion 21 and is fixed thereto. Base 21
, A transverse groove 211 having a U-shaped cross section is formed along the back portion 22. The lateral groove 211 is configured to engage with the flange 131 of the pallet 13 and to slide in the lateral direction while keeping one mold 1 in an upright state.

Here, as the holder 2, the front holder 2
a, a main holder 2b, and a rear holder 2c (FIGS. 1 and 2). With the main holder 2b in the center, these are arranged in a line so that the respective lateral grooves 211, 211, 211 are aligned. Main holder 2a, rear holder 2c
Has a locking portion 23 in which a lateral groove 231 similar to the base portion 21 is formed at the upper end of the back portion 22. This is because the mold 1 is also engaged with the standing mold 1 from above so that the mold 1 does not fall without permission. On the other hand, bearings 24 are fixed to the front holder 2a and the rear holder 2c (FIG. 4). The bearing 24 is on the back side near the joint between the base 21 and the back 22. The support shaft 81 is inserted through the bearing 24, and the front holder 2 a and the rear holder 2 c are structured to be rotatable about the support shaft 81. The support shaft 81 has both ends supported by bearings on the device frame 8. The main holder 2b does not rotate. In an upright state, it is fixed to the device frame 8 (FIG. 5).

The automatic injection machine 3 is a machine for supplying a urethane foam resin raw material, and supplies the raw material from an injection nozzle 31. It faces the main holder 2b (FIG. 5). Main holder 2
With the mold 1 set in b, the automatic injection machine 3 is operated, and when the injection nozzle 31 moves forward, the injection nozzle 31 is inserted into the injection port 112.

Reference numeral 41 denotes a holding lid made of a square Teflon plate. The presser lid 41 faces the main holder 2b,
When the mold 1 is set on the main holder 2b, the front surface thereof is pressed against the mold 1. The compression coil spring 411 is loosely fitted to a support rod that supports the presser lid 41, and the presser lid 41 is always urged forward. The place where the pressing is performed is from the position slightly closer to the rear holder 2c than the injection port 112 to the position where the pressing die 112 is set and the rear holder 2c is applied to the rear holder (FIG. 2). After filling the urethane foam resin material into the cavity, the mold 1 slides sideways, and the injection port 112 enters the holding lid 41, and the holding lid 41 closes the injection port 112. Reference numeral 42 also indicates a holding lid made of a Teflon plate. The presser lid 42 also closes the inlet if the inlet 112 slides into it. It is arranged adjacent to the holding lid 41. However, unlike the presser lid 41, it is configured to rotate in conjunction with the rear holder 2c.

Reference numerals 51, 52, 53, 54 and 55 indicate air cylinders. The air cylinders 51 and 52 are respectively
It functions as an operating body for rotating the front holder 2a and the rear holder 2c up and down. The air cylinder 51 has the main body supported by the apparatus frame 8 and the movable shaft 511 is attached to the front holder 2.
a (FIG. 4). When the air cylinder 51 operates and the movable shaft 511 is extended, the front holder 2a lying horizontally rotates around the support shaft 81 and stands upright on the floor surface. The air cylinder 52 also
The same operation as the air cylinder 51 is performed. When the movable shaft 521 is extended, the rear holder 2c is in an upright state. When the movable shaft 521 contracts, it rotates around the support shaft, and the rear holder 2
c lay down.

The air cylinder 53 serves as a transfer tool for the molding die 1. The air cylinder 53 is arranged beside the front holder 2a. And the front holder 2a, the main holder 2
b, when the rear holder 2c is in the upright state, the side wall of the mold 1 (specifically, the pallet 13) held by the front holder 2a.
Pressing the side wall). By extending the movable shaft 531, the molds 1, 1 held by the front holder 2 a and the main holder 2 b can be slid to the main holder 2 b and the rear holder 2 c. The air cylinder 54 has a role of placing the molding die 1 on the empty front holder 2a. The air cylinder 55 is for placing the molding die 1 placed on the holder 2c after being turned down horizontally on the next conveyor 6.

Reference numeral 6 denotes a conveyor. The holder 2 is arranged at one corner, and the conveyor 6
A circle line as shown in FIG. 3 is formed. The configuration is such that a plurality of molding dies 1, 1,... Rotate on this circle line. In FIG. 3, each mold 1 is moved clockwise. Reference numeral 71 denotes a cure furnace. By heating to a predetermined temperature,
Promotes foam hardening. Reference numeral 72 denotes a work table from which the product is released, and is located just outside the curing furnace 71. Symbol 73 is
This is a tunnel-shaped temperature control cover that covers the conveyor 6. It is for keeping the temperature of the mold 1.

(2) Foam Molding Method Next, an embodiment of the foam molding method according to the present invention using the above foam molding apparatus will be described. The foam molding raw material uses a urethane foam raw material. First, the automatic injector 3, the air cylinders 51, 52, 53, 54, 55, the conveyor 6
For example, turn on the start switch on the operation panel. Then
The molds 1, 1,... Are placed on the conveyor 6 with the upper mold 11 facing upward at a predetermined interval from the work table 72.

Each mold 1 is first heated to a predetermined temperature by the temperature control cover 73. This is because if the mold 1 is too cold, the foam hardening does not proceed. In a steady state, the temperature may be kept low. The heated mold 1 is carried on the conveyor 6 to the first corner 61 (FIG. 3). Then, the air cylinder 54 operates, and the mold 1 is placed on the front holder 2a. When the movable shaft of the air cylinder 54 extends, the flange 131 of the molding die 1 engages with the lateral groove 211 of the front holder 2a. Front holder 2
When the molding die 1 is placed on a, the air cylinder 51 works. By the operation of the air cylinder 51, the front holder 2a that has been in the horizontal state rotates around the support shaft 81 and stands up (FIG. 4). Then, they are always arranged beside the main holder 2b in the upright state.

Here, the mold 1 erected together with the front holder 2a is erected with the gas outlet 111 toward the upper side of the upper mold upper surface and the injection port 112 toward the lower side. As described above, the molds 1, 1,... Are adjusted at the time of being placed on the first conveyor 6 at first. Incidentally, a stopper (not shown) is provided on the apparatus frame 8 so that the mold 1 does not come off from the lateral groove 211 due to the inertial force at the time of finishing the standing.
The stopper comes into contact with the upper part of the mold 1 that has been raised. After a certain period of time from when the front holder 2a stands,
The air cylinder 53 operates. The protrusion of the movable shaft 531 pushes the mold 1 held by the front holder 2a, and the mold 1 slides to the main holder 2b.

When the mold 1 is held by the main holder 2b, the automatic injection machine 3 is operated. The injection nozzle 31 advances, and a predetermined amount of urethane foam material is injected from the injection port 112 into the cavity. Since the injection is performed in a state where the vertically long molding die 1 is standing, the raw material is buried from below. Therefore, the air in the cavity is pushed up and the gas outlet 1
It is discharged from 11. Thus, the molding die 1 is filled with a predetermined amount of the urethane foam raw material. After filling, injection nozzle 3
One retreats. Then, at the same time as the injection nozzle 31 is retracted, the air cylinder 53 starts to move. Here, while filling the molding die 1 with the urethane foam raw material by the automatic injection machine 3, the front holder 2a returns to the horizontal state, receives the next empty molding die 1, and is in an upright state again. The rear holder 2c,
When the injection nozzle 31 retreats, it is empty and upright.

By the operation of the air cylinder 53, the mold 1 held by the front holder 2a moves to the main holder 2b, and the mold 1 held by the main holder 2b moves to the rear holder 2c. The operation of the air cylinder 53 is performed in synchronization with the retreat of the injection nozzle 31, so that the injection port 112 instantaneously enters the presser lid 41. Due to the sealing of the holding lid 41, there is no urethane foam raw material leak from the injection port 112. Finally, the molding die 1 set in the rear holder 2c
During the slide movement process, the injection port 112 is
Instead of 1, it is in contact with the presser lid 42. Presser lid 42 also completely seals inlet 112.

After receiving the molding die 1 from the main holder 2b, the rear holder 2c is turned sideways from the upright position by the action of the air cylinder 52 (FIG. 1). At this time, since the holding lid 42 is fixed to the rear holder 2c so as to interlock with the rear holder 2c, it falls down together with the rear holder 2c. Therefore, the inlet 112 remains closed. After being in the horizontal state, the holder 2c subsequently receives the operation of the air cylinder 55. By the operation of the air cylinder 55, the molding die 1 rides on the conveyor 6 from the rear holder 2c. Here, since the upper side of the upper die 11 of the molding die 1 is upward, and both the inlet 112 and the gas outlet 111 are upward, the urethane foam raw material does not leak out even if the presser lid 42 and the like are no longer provided.

The mold 1 on the conveyor 6 enters the cure furnace 71. And foaming hardening is completed. The molding die 1 that has come out of the curing furnace 71 has finished producing a urethane foam molded article. At the workbench 72, take it out. In this way, a desired urethane foam product is obtained. still,
The empty mold 1 is placed on the conveyor 6 again to perform continuous production. The above-described series of operations is automated by a program that performs the above-described operations from the time when the start switch is turned on, except for operations involving a person at the work table 72.

(3) Effects of the Embodiment According to the foam molding method and apparatus according to the above embodiment, once the foam molding apparatus of the automation line according to the present invention is manufactured, only the mold 1 is replaced. Thus, foam molded articles of various shapes can be manufactured. The mold 1 has a simple box shape and is inexpensive. If the cavities of the molding dies 1, 1, ... arranged on the conveyor 6 are changed, it is possible to cope with many kinds and small quantities. Therefore, it was possible to establish a highly efficient production method for a foam molded product that was not suitable for small-quantity production.

By the mechanization operation, in each operation step, each different operation was added to each mold simultaneously with the other steps, and the production efficiency was remarkably improved. In addition to saving labor, large products can be manufactured, and the degree of freedom has been expanded. And the worktable 72
By simply demolding the product, a foam molded product can be built without any human intervention, and a high-quality and stable product could be produced. For example, at the time of material injection into the cavity,
Since the urethane foam raw material has fluidity and fills from the lower part of the cavity to the upper part, the air in the cavity and the unnecessary reaction gas generated at the initial stage are removed to make a good product. Gas outlet 111, injection port 1
After the third operation of tilting the mold 1 so that the mold 12 faces upward, in addition to the gas outlet 111, the inlet 112 is used to disperse the gas remaining in the cavity to the outside of the mold, so that the gas discharge is further improved. It went smoothly. On the other hand, after the third operation, since it is placed in a state where there is a sense of stability, the subsequent handling of the mold is facilitated, and the transfer to the subsequent process is facilitated. in addition,
There was no need to rely on intuition, and dripping of raw materials from the mold 1 was drastically reduced, and the inside of the factory became clean.

In the present invention, the present invention is not limited to those shown in the above embodiments, but can be variously changed within the scope of the present invention depending on the purpose and application. The size, shape, and the like of the mold 1 and the holder 2 can be variously selected. In the embodiment, three holders 2 are used, but the number is not limited to this number. Further, the holding lids 41 and 42 are eliminated, and the injection nozzle 31 is inserted into the injection port 112.
The molding die 1 can also be turned down while the dies are inserted. The automation line may have an automated line configuration in which only the holder 2 and the automatic injector 3 are automated. It does not require the automation of the conveyor 6 or the like. Not only for small-scale production, but also when used as a production method and apparatus for mass production,
Of course it doesn't matter. The injection of the foam molding material into the cavity by the automatic injecting machine can be performed by using any of the foaming materials of the chemical foaming method and the mechanical foaming method, and is not limited by the foaming method.

[0032]

As described above, the foam molding method and apparatus according to the present invention can be applied to a small number of products while removing the limitation of the conventional product dimensions, promoting labor saving, and ensuring the quality stability. As a result, it is possible to maintain a high quality and a low price and to expand a range in which a foamed molded product can be produced, thereby exhibiting a great effect.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a main part of a foam molding apparatus according to the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a schematic plan view showing the entire foam molding apparatus according to the present invention.

FIG. 4 is a side view around a front holder.

FIG. 5 is a side view around a main holder.

FIG. 6 is an overall perspective view of a molding die.

FIG. 7 is an overall perspective view of a conventional simplified type.

FIG. 8 is an explanatory diagram showing an injection operation when a conventional simple type is used.

FIG. 9 is an explanatory diagram showing an operation after the injection is completed using a conventional simple type.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mold 111 Gas vent 112 Inlet 2 Holder 21 Base 22 Back 3 Automatic injection machine

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 39/02-39/12 B29C 39/22-39/44

Claims (2)

(57) [Claims] 1. A plurality of vertically long molds each having a gas outlet and an injection port on a side face penetrating into a cavity are provided, and the following operations are sequentially performed on each mold in an injection step of an automation line. Characteristic foam molding method. (A) First operation for erecting the mold with the gas outlet at the upper position on the side and the inlet at the lower position. (B) The cavity from the inlet of the mold by an automatic injector. 2nd operation to fill a predetermined amount of foaming raw material in (c) 3rd operation to lower the mold so that the gas outlet and injection port face upward 2. A vertically long mold having a desired cavity formed therein and a gas outlet and an injection port penetrating into the cavity provided on the side surface, a gas outlet at an upper position of the side surface, and an injection mold at a lower position. The mold has a base (21) for holding the mold in an upright state so that the inlet is disposed, and a back (22) attached to the base and abutting against the back surface of the mold, Further, a holder (2) having a back portion rotatable about a joint between the base portion and the back portion is provided, and the holder (2) is mounted on the holder in an upright state. After filling the cavity with the raw material for foam molding by automatic injection machine,
A foam molding apparatus characterized in that a gas outlet and an inlet are turned upward by inverting a holder.