JP2939000B2 - Game machine frame and molding method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin frame constituting a machine body of a game machine represented by a pachinko game machine, a coin game machine, a slot machine, and the like, and a molding method thereof.

[0002]

2. Description of the Related Art Conventionally, when a thermoplastic synthetic resin is injection-molded, if the thickness of the molded product exceeds 4 mm, first, as shown in FIG. When the layer 17 is solidified and then the resin of the inner layer 19 is solidified, there is a disadvantage that surface defects such as sink marks h occur due to shrinkage. Therefore, there is a method of injecting a foamable thermoplastic resin into an injection molding machine and absorbing the volumetric shrinkage of the resin in the injection molding machine when the resin is solidified by internal foaming of the resin to prevent the above-described inconvenience. is there. However, in the case of this method, the resin flows on the inner surface of the injection molding device while foaming in the injection molding device such as a mold cavity, so that the air bubbles are pressed against the inner surface of the injection molding device and collapsed, so-called swirl marks or the like. And the surface of the molded article becomes uneven.

As a method for solving the irregularities on the surface of a molded product caused by the swirl mark or the like, for example, Japanese Unexamined Patent Publication No.
The conventional molding method disclosed in Japanese Patent No. 5182 is referred to as a sandwich molding method.
Using one cylinder, first inject the non-foamable resin into the injection molding machine from one cylinder, then press-inject the foamable resin into the non-foamable resin from the other cylinder and inject it into the surface. A resin layer is formed and a foam layer is formed inside the resin layer.

[0004]

However, in the case of this sandwich molding method, when the foamable resin is injected, the laminar flow property of the resin inside the injection molding device is broken and turbulence is generated, and the non-foamable resin is formed. And the foamable resin inside the foamable resin are mixed with each other, and the foamable resin and the inner surface of the injection molding device may come into contact with each other, so that the above-mentioned so-called swirl mark may be generated. In particular, the more complicated the frame of the amusement machine, the higher the possibility of turbulent resin flow in the injection molding machine described above. In order to prevent this, there is a disadvantage that the shape of the frame of the gaming machine must be simplified.

The present invention has been conceived in view of the above circumstances, and an object of the present invention is to prevent a surface of a molding frame such as a swirl mark from being uneven and to obtain a smooth surface, while obtaining a smooth surface. Is to be able to mold the gaming machine frame of the present invention.

[0006]

According to a first aspect of the present invention, there is provided a game machine frame according to the present invention, wherein the synthetic resin frame constituting the machine body of the game machine forms a surface layer of the frame body. Including a surface skin layer and a foam layer inside the surface skin layer, the surface skin layer was formed by injecting a foamable thermoplastic resin into an injection molding machine under pressure and foaming was suppressed by the pressure in the injection molding machine. A foamed resin layer in which the resin surface is cooled and solidified by cooling, and the foamed layer inside the foamed resin is foamed by a decrease in internal pressure in a state where the inside of the surface skin layer is not yet solidified. It is characterized by including a layer.

According to a second aspect of the present invention, there is provided a method for molding a synthetic resin frame constituting a machine body of a game machine, wherein a foamable thermoplastic resin is injected into an injection molding machine under pressure. A second step of cooling and solidifying only the surface of the resin to form a surface skin layer of the frame in a state where foaming is suppressed by the pressure in the injection molding device; A third step in which the resin inside the surface skin layer foams due to a decrease in internal pressure in a state where the inside of the skin layer has not yet been solidified to form an internal foam layer.

[0008]

According to the first aspect of the present invention, the frame includes a surface skin layer forming a surface layer of the frame and a foam layer inside the surface skin layer. The surface skin layer is a foam-suppressing resin layer in which a foamable thermoplastic resin is injected into the injection molding machine under pressure, and the resin surface is cooled and solidified while foaming is suppressed by the pressure in the injection molding machine. Contains. Therefore, since the foaming of the resin portion in contact with the inner surface of the injection molding device is suppressed, there is no inconvenience such as a swirl mark which is generated when air bubbles accompanying the foaming of the resin come into contact with the inner surface of the injection molding device and are crushed. In addition, as a method of forming a foam layer inside the surface skin layer, since the foam is generated by lowering the internal pressure in a state where the inside of the surface skin layer is not yet solidified, the sandwich molding described above is performed. Unlike the method, there is no need to forcibly press-fit and inject the foamed resin layer to force the resin to flow in the injection molding machine, and the frame body has the foamed layer formed inside the surface skin layer without difficulty.

According to the second aspect of the present invention, in the first step, the foamable thermoplastic resin is injected into the injection molding machine under pressure, and in the second step, the thermoplastic resin is injected into the injection molding machine. The foamed resin is suppressed by the pressure in the injection molding machine, and only the surface of the resin is cooled and solidified to form a surface skin layer of the frame. Next, in a third step, the resin inside the surface skin layer foams due to a decrease in the internal pressure in a state where the inside of the surface skin layer has not been solidified yet, and an internal foam layer is formed.

That is, since the resin in which foaming is suppressed is brought into contact with the inner surface of the injection molding device by the second step, the swirl formed by the bubbles caused by the foaming of the resin coming into contact with the inner surface of the injection molding device and being crushed. As a method of forming a foamed layer inside the surface skin layer while preventing inconvenience of generation of marks, etc., foaming of foamable resin is allowed due to a decrease in internal pressure, and the inside of the surface skin layer naturally naturally It is not necessary to foam the resin and force the resin to flow in the injection molding machine by press-fitting the foamable resin as in the sandwich molding method described above.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 1 to 4 are process diagrams for explaining the procedure of a counter pressure method which is an example of a method of forming a frame of a gaming machine according to the present invention. The mold 1 constituting the injection molding device is constituted by a combination of divided bodies including a first divided body (female mold) 2, a second divided body 3 and a third divided body (male mold) 4. ing. A cavity 6, which is a space into which the resin injected from the nozzle 5 flows, is formed between the first divided body 2 and the third divided body 4. This mold 1
Has a sealed structure, and the cavity 6 of the mold 1
A compressor 7 for injecting a gas made of air or the like into the inside is provided. In the figure, reference numeral 8 denotes a relief valve, and the pressure in the cavity 6 is adjusted by the compressor 7 and the relief valve 8 so as to be 10 to 15 kg / cm ² .

The synthetic resin material used is desirably made of ABS resin or polystyrene mixed with a foaming agent. This is because these resins have a good foaming state as compared with other synthetic resins, and have an advantage that bubbles are fine and uniform. On the other hand, as the foaming agent, an organic foaming agent whose generated gas is N ₂ is mainly used. Further, an inorganic foaming agent such as sodium bicarbonate or ammonium carbonate may be used. When such an inorganic foaming agent is used, a product having a low decomposition temperature, moderate gas generation, and a relatively low foaming rate of the internal foam layer can be obtained.

[0014] Such a synthetic resin material is first heated and melted, and the above-mentioned blowing agent is mixed into the melted synthetic resin material. The synthetic resin material mixed with the blowing agent is immediately put into a predetermined accumulator. Let it accumulate. In the accumulator, the molten resin is heated so as not to be solidified, and is pressurized so that the resin accumulated in the accumulator does not foam.

Next, as shown in FIG. 2, the compressor 7 is operated to increase the pressure in the cavity 6 to 10 to 15 kg.
The resin in the accumulator is injected from the nozzle 5 into the cavity 6 under a pressure of about / cm ² . In this state, since the inside of the cavity 6 is pressurized,
The resin 9 injected into the cavity 6 is filled in the entire cavity 6 with foaming suppressed. The pressurization in the cavity 6 is continued until just before the filling of the resin is completed. The step of filling the cavity 6 with the resin 9 constitutes a first step of injecting the foamable thermoplastic resin into the injection molding machine under pressure.

Next, as shown in FIG. 3, while foaming of the resin in the cavity 6 is suppressed, only the surface of the resin is cooled and solidified to form a foam suppressing resin layer. The foaming suppressing resin layer constitutes a surface skin layer of the molded product. In a state where foaming is suppressed by the pressure in the injection molding device, only the surface of the resin is cooled and solidified to form a surface skin layer of the frame. Is formed.

Next, after the surface skin layer is formed, the molten resin inside the surface skin layer starts to be solidified by further cooling. When the resin is solidified, its volume shrinks, so that the pressure inside the surface skin layer decreases. As a result, the molten resin inside the surface skin layer starts foaming, and is cooled and solidified while foaming, and an internal foam layer is formed inside the surface skin layer. The formation of this internal foam layer is the third step. The expansion ratio of this molded product is set to 1.05 or less. As a result, the resin can be freely selected and the foaming pressure can be set low, so that there is an advantage that there is no risk of secondary foaming and the cooling time can be shortened. In this embodiment, the cooling time is about 6 hours.
It is about 0 seconds.

Next, as shown in FIG. 4, when the cooling is completed, the first divided body 2 and the third divided body 4 are separated from each other, and the molded product 10 is taken out.

FIGS. 5 to 8 show another example of the frame forming method of the present invention, and are process charts showing the procedure of forming the frame.

Referring to FIG. 5, a mold 1 constituting an injection molding machine includes a first divided body (female mold) 12 and a second divided body 1
3 and a third divided body (male type) 14 are combined. A cavity 6, which is a space into which the resin injected from the nozzle 5 flows, is formed between the first divided body 12 and the third divided body. The mold 1 has a sealed structure, and a compressor 7 is provided in a cavity 6.
Gas such as air is pressurized from the inside, and the pressure in the cavity 6 is increased by 10 to 15 k by the compressor 7 and the relief valve 8.
It is configured so that it can be pressurized to a desired pressure of about g / cm ² . The third split body 14 includes a compression spring 16
And the compression spring 1
6, the second divided body 13 is pressed to the right in the drawing in FIG. 5, and the tip of the piston 15 is connected to the second divided body 13. Further, the hydraulic cylinder 11 is connected to the second divided body 13, and the hydraulic cylinder 11 is driven to drive the second divided body 13 and the first divided body 13.
7 is integrally moved in the right direction in the figure as shown in FIG. The amount of movement is restricted to a small amount that allows the piston 15 to expand and contract.

In the injection molding machine having such a configuration, first, a molten resin made of foamed resin is injected into the cavity 6 from the nozzle 5 in the same manner as described above. In that state,
Since the pressure in the cavity 6 is pressurized by the compressor 7 and the relief valve 8 so that the pressure in the cavity 6 becomes the above-described desired pressure, the molten resin injected into the cavity 6 is maintained in a state where foaming is suppressed. Fill in 6. The step of filling the cavity 6 with the resin constitutes a first step of injecting the foamable thermoplastic resin into the injection molding machine under pressure.

Next, as shown in FIG. 6, when the cavity 6 is filled with resin, the operation of the compressor 7 is stopped to keep the cavity 6 airtight. In that state,
The surface of the resin 9 in the cavity 6 is cooled and solidified while foaming is suppressed. As a result, on the surface of the resin 9, a surface skin layer made of a foam-suppressing resin layer solidified while foaming is suppressed is formed. The step of forming the surface skin layer constitutes the second step.

Next, after the surface skin layer is formed, the molten resin inside the surface skin layer solidifies with the progress of cooling. The pressure inside the surface skin layer will decrease. Further, at that stage, as shown in FIG.
The first divided body 12 is slightly pulled away from 4 to increase the volume in the cavity 6. Then, both the volume shrinkage and the expansion of the volume in the cavity 6 greatly reduce the pressure of the molten resin inside the surface skin layer,
Along with this, the molten resin inside the surface skin layer foams and cools and solidifies while foaming, forming an internal foam layer. The step of forming the internal foamed resin layer is a third step.

Next, when the cooling of the resin is completed, the hydraulic cylinder 11 is operated as shown in FIG. 8 to separate the first divided body 12 and the third divided body 14 to take out a molded product.

In the case of the mold enlarging method shown in FIGS. 5 to 8, the expansion ratio is 1 to 3 times as wide as that of the counter pressure method shown in FIGS. And there is an advantage that the tolerance of the thickness change of the molded product is high. In addition, since the mold is expanded and foamed after the formation of the surface layer, secondary foaming is less likely to occur and the cooling time can be reduced. Further, by adjusting the enlargement amount of the mold, the surface skin layer can be made uniform and the thickness of the surface skin layer can be controlled. Furthermore, there is an advantage that the foam cells of the internal foam layer can be made very uniform.

FIG. 9 is a sectional view of a molded article formed by the injection molding method shown in FIGS. 1 to 4 or 5 to 8. In the figure, reference numeral 20a denotes a surface skin layer made of the above-described foam-suppressing resin layer, and reference numeral 21 denotes an internal foam layer made of the above-described foamed resin layer.

FIG. 10 is an external perspective view of a pachinko gaming machine 101 as an example of the gaming machine. In the figure, the pachinko gaming machine 101 includes an outer frame 102 and a front frame 103. Outer frame 1
02 holds the front frame 103 via the hinge 135. Therefore, the front frame 103 was attached to the upper left and lower sides when viewed from the front.
Rotate (open / close) with respect to the outer frame 102 around the hinge 135
It is possible.

In FIG. 10, reference numeral 131 denotes a metal frame;
32 is a glass door frame, 133 is a ball tray, 134 is an operation handle, 136 is a front plate, 137 is a prize ball payout port, 138
Reference numeral denotes a hit ball supply tray, all of which are attached to the front frame 103.

FIG. 11 is a front perspective view of a front frame 103 of an example of a synthetic resin frame formed by the injection molding method shown in FIGS. FIG. 12 shows the front frame 103.
It is a perspective view of the back side. Referring to FIGS. 11 and 12, front frame 103 of pachinko gaming machine 101 has a frame-like shape in which window hole 301 is formed substantially at the center. Window hole 30
A groove 302 is formed on the front edge of the front frame 103 at the periphery of the first frame 103. The glass door frame 132 described above is fitted into the groove 302. Further, a through hole 304 for attaching an operation handle and a ball receiving tray communication port 303 are formed below the front frame 103. Further, small holes 305 for mounting various components such as a decoration stand and a ball tray are formed as necessary. Further, in the figure, reference numeral 320 denotes a game board mounting member for mounting the game board, which is integrally formed with the front frame 103. A hitting ball shooting rail (not shown) is mounted on the front side 320A of the game board mounting member 320. Also, a through hole 304 for an operation handle of the front frame 103 is provided.
A hitting hammer is attached in connection with the. The pachinko ball hit with a hitting ball hammer is guided to the game board surface along a hit ball launching rail provided on the front side 320A of the game board mounting member 320. Front frame 1 including the game board mounting member 320
03 is integrally molded, the positional relationship between the hitting hammer to be attached to the front frame 103 and the hitting firing rail to be attached to the game board attachment member 320 is accurate, and the movement of the pachinko balls is also smooth. There is. In the figure, reference numeral 321 denotes a prize ball contact.

FIG. 13 shows another example of a frame made of synthetic resin. It is a perspective view of the outer frame 102 of the pachinko gaming machine. As viewed from the front, a thin portion 121 is provided at the upper left of the outer frame 102 for attaching a support bracket (not shown) for supporting a hinge 135 (see FIG. 10) attached to the front frame 103. Are formed. Also, on the right inside front,
A groove 122 is formed. This is for providing a locking mechanism for the front frame 103.

Also, on the lower front surface 123 of the outer frame 102,
It is desirable to bond a thermosetting resin plate, for example, a thin plate 124 formed of melamine. Thus, the outer frame 1
When a thermosetting resin plate 124 is bonded to a surface 123 that can be easily touched from the outside of the outer frame 102 when the front frame 103 and the like are fitted into the pachinko gaming machine 02, for example, the player However, when a cigarette or the like accidentally contacts the front of the outer frame, the outer frame 102 can be prevented from being discolored or deformed by the heat of the fire or the like, and a beautiful appearance can be maintained. The thermosetting resin plate 124
Instead of this, for example, an aluminum plate may be bonded here, or a surface treatment with ultra violet may be performed. Bonding of the outer frame front surface 123 to the thermosetting resin plate 124 or the aluminum plate can be easily performed with an adhesive, a set screw, or the like. When bonding with an adhesive, it is preferable to apply an adhesive after heating the front surface 123 of the outer frame 102 and bond the thermosetting resin plate 124 and the like. This is because the bonding strength between the front surface 123 and the bonding plate 124 can be enhanced by heating.

In this embodiment, the front frame and the outer frame of the pachinko game machine are shown as the frames constituting the machine body of the game machine, but the present invention is not limited to this, and the game machine such as a slot machine may be used. It may be a frame constituting the body of the machine.

FIG. 14 is a front view showing the ball box 23.
The ball box 23 stores prize balls obtained as a result of playing a game with a pachinko gaming machine. The ball box 23 is made of a synthetic resin and has a cross section as shown in FIG. Reference numeral 24 in FIG. 15 denotes a bottom plate portion of the ball box 23, which is formed in an arch shape protruding upward as shown in the figure. Since the pachinko balls are stored in the ball box 23 and the load is applied to the bottom plate portion 24 because of the arch shape, the load from above is due to the arch shape. The advantage is that the inconvenience that the bottom plate portion 24 is deformed by the load of the stored pachinko balls can be prevented as much as possible.

[0034]

According to the first aspect of the present invention, the surface of the frame is formed of a surface skin layer made of a foamed synthetic resin layer, and irregularities on the surface of the molded frame such as swirl marks are prevented as much as possible to provide a smooth surface. Because the foamed layer inside the surface skin layer is formed by the foamed resin layer formed naturally by the internal molten resin foaming naturally due to the decrease in the pressure inside the surface skin layer, It has become possible to provide a frame having a complicated shape in which a foamed layer is favorably formed inside the layer.

According to the second aspect of the present invention, only the surface of the resin is cooled and the solidified surface skin layer is formed in a state in which foaming is suppressed by the second step. Because the resin is solidified in a state where foaming is suppressed, the foam due to foaming can be pressed against the inner surface of the injection molding machine to prevent irregularities on the surface of the molded body such as swirl marks generated by crushing, and a frame with a smooth surface Can be molded. Further, in the third step, the internal foam layer is formed by cooling and solidifying the molten resin inside the surface skin layer while foaming due to a decrease in the pressure inside the surface skin layer, and the resin is forced to flow. Since a method is used in which the internal resin foams spontaneously due to a decrease in pressure without causing the foam, a foamed layer can be easily formed inside even a frame having a complicated shape.

[Brief description of the drawings]

FIG. 1 is a process diagram showing an example of a method of forming a frame of a gaming machine.

FIG. 2 is a process chart showing an example of a method of forming a frame of a gaming machine.

FIG. 3 is a process chart showing an example of a method of forming a frame of a gaming machine.

FIG. 4 is a process chart showing an example of a method of forming a frame of a gaming machine.

FIG. 5 is a process chart showing another example of a method of forming a frame of a gaming machine.

FIG. 6 is a process chart showing another example of a method of forming a frame of a gaming machine.

FIG. 7 is a process chart showing another example of a method of forming a frame of a gaming machine.

FIG. 8 is a process chart showing another example of a method of forming a frame of a gaming machine.

FIG. 9 is a cross-sectional view showing a cross section of a frame which is a molded product formed by the method of molding a frame of a gaming machine according to the present invention.

FIG. 10 is a perspective view showing a pachinko gaming machine as an example of the gaming machine.

FIG. 11 is a perspective view showing a front side of a front frame which is an example of a frame of the gaming machine according to the present invention.

FIG. 12 is a perspective view showing a rear surface side of a front frame.

FIG. 13 is a perspective view showing an outer frame of another example of the frame of the gaming machine according to the present invention.

FIG. 14 is a front view of the ball case.

FIG. 15 is a cross-sectional view of the ball case.

FIG. 16 is an operation explanatory view showing a frame forming method in a conventional example.

[Explanation of symbols]

1 is a mold, 2 and 12 are first divided bodies, 3 and 13 are second divided bodies, 4 and 14 are third divided bodies, 6 is a cavity, 9
Is a resin, 20a is a surface skin layer, 21 is a foam layer, 103
Denotes a front frame, and 102 denotes an outer frame.

Claims (2)

(57) [Claims] 1. A frame made of a synthetic resin constituting a machine body of a gaming machine includes a surface skin layer forming a surface layer of the frame body and a foam layer inside the frame body. A foaming-suppressed resin layer in which the thermoplastic resin having a surface is cooled and solidified by injecting a thermoplastic resin into the injection molding machine under pressure and foaming is suppressed by the pressure in the injection molding machine; The frame of a gaming machine, wherein the layer includes a foamed resin layer in which the inside of the surface skin layer has not yet been solidified and foaming has occurred due to a decrease in internal pressure. 2. A method of molding a synthetic resin frame constituting a machine body of a gaming machine, comprising: a first step of injecting a foamable thermoplastic resin into an injection molding machine under pressure; A second step in which only the surface of the resin is cooled and solidified to form a surface skin layer of the frame in a state in which foaming is suppressed by the pressure in the injection molding device, and the inside of the surface skin layer is still solidified A third step in which the resin inside the surface skin layer foams due to a decrease in internal pressure in a state where the internal skin layer is not formed, thereby forming an internal foam layer.