JPH10119084A - Insert molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insert molding machine in which density of molten resin in a cavity can be made uniform even if supply of the molten resin into the cavity is conducted substantially by non-pressure. SOLUTION: The insert molding machine comprises a mold 23 having a cavity 33 in which a gas sensing element 7 is mounted as a brittle insert component, an injecting mechanism 2 for injecting molten resin in the cavity, a content removing mechanism 27 having a housing 59 including a cylinder chamber 63, a plunger 67 provided in the housing and a plunger driver 61, and a continuous sleeve 65 in which the cavity is continued to spaces of the cylinder chamber. In this case, gas in the cavity and/or the molten resin of substantially the same volume as supplied molten resin is extracted to the cylinder chamber substantially in synchronization with supply of the molten resin to the cavity. Thus, even if the supply of the molten resin to the cavity is conducted by non-pressure, the cavity can be held substantially no-pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insert molding apparatus, and more particularly to an insert molding apparatus for insert-molding a fragile insert part with a required body using a synthetic resin.

[0002]

2. Description of the Related Art In insert molding using an injection molding method, molding is performed by injecting a molten resin into a cavity in which an insert component is arranged. 700 kg / cm ² to 800 kg /
cm ² . Therefore, if the insert part has low rigidity, the insert part may be damaged or deformed by the injection pressure or flow rate of the molten resin. In this case, the injection pressure is reduced to about 100 kg / cm ^2. An injection method is often used.

[0003]

However, when the insert part is fragile, such as extremely thin glass,
Even if the injection pressure is reduced to the above-mentioned level, damage or deformation cannot be reliably prevented. In addition, in the low-pressure injection method, there is a problem that the injection of the molten resin is performed very slowly, so that it takes a long time to mold, and moreover, since the pressure supplied to the resin supplied into the cavity is not evenly applied. There is also a problem that the density of the resin in the cavity is inevitably uneven.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. Even when the injection pressure of the molten resin is not zero, the molten resin can be injected with the pressure in the cavity being substantially zero. An object of the present invention is to provide an insert molding device.

Another object of the present invention is to provide an insert molding apparatus capable of making the density of the molten resin in the cavity uniform even when the molten resin is supplied to the cavity under substantially no pressure. .

[0006]

SUMMARY OF THE INVENTION The invention of claim 1 is an insert molding apparatus for insert-molding a fragile insert part together with a required body with a synthetic resin, wherein the insert part is removably mounted in a cavity. Molten resin supply means for supplying the molten resin into the apparatus, and extraction means for extracting the contents of the cavity, and substantially in synchronization with the supply of the molten resin, the cavity contents having substantially the same volume as the supplied molten resin are provided. An insert molding device characterized in that the insert molding device is drawn out of a cavity.

According to a second aspect of the present invention, there is provided a resin tank for storing a molten resin, a pressurizing chamber provided with a pressurizing means, a fragile insert having an open upper surface, or a fragile insert being held by a synthetic resin. A mold having a cavity in which a primary molded product is detachably mounted, the mold being movably provided between the resin tank and the pressurizing chamber, and a mold in a resin tank in which molten resin is stored. Characterized in that the molten resin in the cavity is pressurized in the pressurizing chamber after the molten resin is poured into the cavity by immersing the molten resin in the cavity.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an insert molding apparatus 1 according to the first embodiment of the present invention. Reference numeral 3 denotes an automobile part as a molded product (see FIG. 4).
And FIG. 5). The automobile part 3 is formed through two-stage molding by the insert molding device 1 and another insert molding device described later.

Reference numeral 5 denotes a primary molded product of the automobile part 3, and the primary molded product 5 is molded by the insert molding device 1.
The primary molded product 5 includes a gas detection element 7 as a fragile insert part, and a synthetic resin body 9 holding the gas detection element 7 in a substantially embedded state. The body 9 is formed in a rectangular parallelepiped shape. The gas detecting element 7 has a rectangular flat plate shape, a thickness of about 0.2 mm, and a long side of about several mm. The gas detection element 7 is provided in a posture inclined by 45 ° with respect to the longitudinal direction of the body 9.

Reference numeral 11 denotes a gas entry path formed in the body 9, and reference numeral 13 denotes a gas entry path formed in the body 9.
The gas entrance path 11 is formed so as to extend in the longitudinal direction through a central portion of the body 9, and the gas entrance path 13 is formed to extend from a middle part of the gas entrance path 11 in a direction perpendicular to the gas entrance path 11. A cutout 14 is formed in the body 9, and both ends of the gas detection element 7 are exposed from the cutout 14. The notch 14 is a space where the gas detection element holding portions for holding both ends of the gas detection element 7 were located when the primary molded article 5 was formed.

Reference numeral 15 denotes a main body of the automobile part 3. The main body 15 is formed by another insert molding device described later, and has a substantially convex shape. The main body 15 has the primary molded article 5 embedded at a position corresponding to the protrusion 17, and has an outgoing gas approach path 19 continuous with the gas approach path 11 and an outgoing gas approach path continuous with the gas approach path 13. 21 are formed.

The insert molding apparatus 1 has approximately two
A mold 23 formed in a split, an injection mechanism 25 for injecting the molten resin into the mold 23, and the contents in the cavity of the mold 23 substantially in synchronization with the injection of the molten resin into the mold 23. It is composed of a content extracting mechanism 27 for extracting an object.

The mold 23 comprises a fixed mold 29 on the right and a movable mold 31 on the left. When the fixed mold 29 and the movable mold 31 are closed, a cavity 33 that defines the outer shape of the body 9 of the primary molded product 5 is formed.
° is inclined. Reference numeral 37 denotes a component mounting block. The component mounting block 37 is supported by a fixed mold 29.
The component mounting blocks 37 are provided so as to be located near both ends of the dividing surface 35, and both ends of the gas detection element 7 are separately held by the component mounting blocks 37.

Reference numeral 39 denotes a projection for forming a gas entrance path on the fixed die 29 side, and reference numeral 41 denotes a projection for forming a gas entrance path on the movable die 31 side. Reference numeral 43 denotes a slide pin slidably supported by the fixed mold 29. These gas entry path forming projections 3
The gas inflow path 11 and the gas inflow path 13 of the primary molded article 5 are formed by 9 and 41 and the slide pin 43. 45
Denotes a fixed die plate, and a fixed die 29 is fixed to the left side surface of the fixed die plate 45.

The injection mechanism 25 comprises a heating cylinder 49 having a torpedo 47, an injection plunger 51 and the like. The tip of the torpedo 47 opens inside the fixed mold 29, and the injection plunger 51 is driven, so that the heated molten resin is injected into the cavity 33.

Reference numeral 53 denotes a moving die plate that is moved by a mold clamping cylinder (not shown). Reference numeral 55 denotes a cylinder mounting plate located on the right side of the moving die plate 53, and the cylinder mounting plate 55 is supported by the moving die plate 53 by guide pins 57.

The contents extracting mechanism 27 includes a housing 59 fixed to the right side of the cylinder mounting plate 55, a plunger drive 61 fixed to the left side of the cylinder mounting plate 55, and a cylinder chamber formed in the housing 59. It is composed of a continuous sleeve 65 or the like that continuously connects the internal space of the fixed mold 29 to the internal space 63. The cylinder chamber 63 is formed so as to form a cylindrical space, and a plunger 67 moved by the plunger driving unit 61 is disposed in the cylinder chamber 63.

The movable mold 31 is fixed to the right side of the housing 59. Therefore, when the movable die plate 53 is moved, the contents extracting mechanism 27 and the movable mold 31 move integrally, and the mold 23 is opened and closed.
The mold 23 is closed after the gas detection element 7 is mounted on the component mounting block 37, and the mold 33 is closed from that state.
Is injected to form a primary molded product 5.

The continuous sleeve 65 is embedded between the base 69 and the housing 59 of the movable die 31, and has a left end opening into the cylinder chamber 63 and a right end opening inside the movable die 31. Therefore, when the mold 23 is closed, the cavity 33 and the cylinder chamber 63 are connected to each other through the hole 71 of the continuous sleeve 65. In this state, the gas and / or the molten resin, which are the contents in the cavity 33, are drawn into the cylinder chamber 63 through the continuous sleeve 65 when the plunger 67 retreats to the left.

The hole 71 of the continuous sleeve 65 is tapered so that the diameter decreases toward the right.
1 has an extremely small diameter end. Reference numeral 73 denotes a discharge hole formed at the left end of the housing 59, and the gas and / or the molten resin drawn into the cylinder chamber 63 is discharged out of the housing 59 through the discharge hole 73.

Reference numeral 75 denotes a control unit. The control unit 75 drives the plunger drive unit 61. A proxy value signal of the temporal volume of the molten resin injected into the cavity 33 by the injection mechanism 25 is input to the control unit 75. Further, a drive signal having a value corresponding to the proxy value signal is output to the plunger drive unit 61 with time, whereby the plunger 67 is retracted with time. The value of the drive signal is a value corresponding to the amount by which the plunger 67 withdraws the content having substantially the same volume as the volume of the molten resin from the cavity 33. Therefore, the retreat of the plunger 67 is performed substantially in synchronization with the injection of the molten resin into the cavity 33.

By such an operation by the contents extracting mechanism 27, even if the molten resin is injected into the cavity 33 with pressure, the inside of the cavity 33 is kept substantially free of pressure. Therefore, since the injection pressure of the molten resin is hardly applied to the gas detection element 7 disposed in the cavity 33, it is possible to almost certainly prevent the gas detection element 7 from being damaged by the injection pressure of the molten resin. Can be.

Reference numeral 77 denotes a heater.
Is built in the housing 59. This heater 77
Is for preventing the molten resin in the cylinder chamber 63 and the continuous sleeve 65 from solidifying. Reference numeral 79 denotes an eject plate. The eject plate 79 is slidably supported by the guide pins 57. As the eject plate 79 advances rightward, the eject pins 81 push the primary molded product 5 out of the mold 23.

FIGS. 2 and 3 show an insert molding apparatus 83 according to an embodiment of the present invention. The main body 15 of the automobile part 3 is molded by the insert molding device 83 in a state where the primary molded product 5 is inserted.

The insert molding device 83 moves in the same direction with the resin tank 87 and the pressurizing chamber 89 fixed to the base plate 85 side by side and penetrating the resin tank 87 and the pressurizing chamber 89 in the left-right direction. And the like.

Reference numeral 93 denotes a base block of the mold 91.
The base block 93 has a horizontally long rectangular column shape, and is moved by a moving mechanism (not shown). The pressurized concave portion 9 which is slightly larger and shallower than the planar shape of the main body 15 is provided at an intermediate portion of the base block 93 in the left-right direction.
5 are formed. Reference numeral 97 denotes a cavity formed in the base block 93, and the cavity 97 defines the outer shape of the main body 15. The cavity 97 is oriented such that a concave portion 99 corresponding to the protrusion 17 of the main body 15 is located below, and the upper surface 101 is open to the concave portion 95 to be pressed.

Reference numeral 103 denotes a gas entry path forming pin, and the gas entry path forming pin 103 rises vertically from the bottom of the recess 99. Reference numeral 105 denotes a pair of left and right gas entry path forming pins. The gas entry path formation pins 105 slide in guide holes 107 formed in the left and right sides of the cavity 97 in the base block 93 so as to extend in the left and right direction. It is freely inserted. The gas entry path forming pin 105 is moved by a cylinder (not shown) provided in the cylinder arrangement space 109. 111 is the cavity 97
Shows an ejection mechanism arrangement space provided below the ejection mechanism arrangement space 111 and the cavity 97.
An eject pin 115 is slidably inserted into a guide hole 113 that penetrates a portion between them.

The cavity 97 is provided with a component mounting portion (not shown) projecting upward from the bottom surface thereof.
The primary molded product 5 is mounted on the component mounting portion. When the primary molded article 5 is mounted in the cavity 97, the upper end of the gas entry path forming pin 103 is relatively inserted into the gas entry path 13 of the primary molded article 5, and from this state, the left and right gas entry path forming pins 105 are formed. Is inserted into the gas passage 11 of the primary molded product 5.

A relatively large insertion hole 119 into which the base block 93 of the mold 91 fits tightly is formed in the lower half of each side wall 117 of the resin tank 87 and the pressure chamber 89 in the left-right direction. The base block 93 is slidably inserted into these insertion holes 119.

The horizontal cross section of the internal space 121 of the resin tank 87 is one size larger than the pressurized concave portion 95 formed in the base block 93. Reference numeral 123 denotes a nozzle. The nozzle 123 penetrates through the top wall 125 of the resin tank 87 and faces the internal space 121 of the resin tank 87. The molten resin 127 is intermittently supplied from the nozzle 123 to the resin tank 87. You. Molten resin 127 supplied to resin tank 87
Is a quantity somewhat larger than the internal volume of the cavity 97.

The horizontal section of the internal space 129 of the pressurizing chamber 89 has the same size as the concave portion 95 to be pressurized. 131
Denotes a pressure plate, and the pressure plate 131 is provided in an internal space 129 of the pressure chamber 89. The pressure plate 131 is fixed to a piston rod 133 of an air cylinder disposed above the pressure chamber 89, and is substantially in close contact with the inner wall surface of the internal space 129.

In the initial state, the mold 91 has reached the eject position where the cavity 97 has retreated to the right from the pressurizing chamber 89. At this position, the primary molded product 5 is mounted in the cavity 97. During this time, the resin tank 87
Is supplied with a predetermined amount of molten resin 127, whereby
A portion of the base block 93 located in the resin tank 87 is buried in the molten resin 127.

From this state, the mold 91 moves to the left relatively slowly. Then, when the cavity 97 enters the resin chamber 87, the molten resin 127 gradually flows into the pressurized concave portion 95 and the cavity 97, and the movement of the mold 91 stops when the entire cavity 97 enters the resin tank 87. I do. This state is the state shown in FIG. Therefore, since the supply of the molten resin 127 to the cavity 97 is determined by the weight of the molten resin 127, pressure is hardly applied to the primary molded product 5 as an insert part.

Here, the mold 91 waits for a predetermined time, and after this time elapses, the degassing of the molten resin 127 flowing into the cavity 97 proceeds. Next, the mold 91 moves to the right. At this time, the portion of the molten resin 127 that does not enter the pressurized concave portions 95 and the cavities 97 is
19 is left in the resin tank 87 by being worn by the upper side surface. The entirety of the pressurized concave portion 95 is
When it enters, the movement of the mold 91 stops. here,
The pressing plate 131 is lowered until it comes into contact with the bottom surface of the pressed concave portion 95. As a result, the pressurized recess 95
Is pushed into the cavity 97, so that the molten resin 127 in the cavity 97
7 is pressed to make the density uniform.

Then, the molten resin 12 in the cavity 97 is
After the cooling and solidification of 7, the mold 91 is moved to the initial position, where the eject pin 115 rises and the primary molded product 5 is taken out.

Although the embodiment of the present invention has been described in detail above, the specific configuration is not limited to this embodiment, and the design may be changed without departing from the scope of the present invention. Are also included in the present invention. For example, the content extracting mechanism in the present invention is not limited to the system shown in the embodiment, and the cavity content having substantially the same volume as the supplied molten resin is substantially synchronized with the supply of the molten resin. Any material may be used as long as it has a function of extracting the outside of the cavity.

In the embodiment, the case where the insert component is a gas detecting element has been described as an example. However, the insert component to which the present invention can be applied is not limited to such a type, and is fragile. With such a component, an effect similar to the effect in the embodiment can be obtained.
In addition, in the said embodiment, although the case where the insert molding machine 1 and the insert molding machine 83 are used continuously for manufacturing the automobile part 3 was shown, the insert molding machine 1 and the insert molding machine 83 Needless to say, they may be used in the case of independently producing separate products.

[0038]

As described above, according to the first aspect of the present invention, the pressure generated in the cavity due to the injection of the molten resin is canceled out by the contents of the cavity being drawn out of the cavity, and is substantially zero. become. This allows
Even if the supply of the molten resin to the cavity is performed under pressure, pressure is hardly applied to the insert parts and the like in the cavity, so that it is possible to almost certainly prevent the insert parts and the like from being damaged, Moreover, since there is no need to supply the molten resin slowly, the molding time can be reduced.

According to the second aspect of the present invention, the supply of the molten resin to the cavity is caused only by the flow of the molten resin by its own weight. In this supply, pressure is applied to the insert part or the primary molded product in addition to the weight of the molten resin. There is nothing. Then, the molten resin supplied to the cavity is pressurized in the pressure chamber, so that the density is made uniform. Therefore,
It is possible to almost certainly prevent the insert parts and the like from being damaged by the supply of the molten resin, and it is not necessary to particularly limit the supply amount per hour, so that the molding speed can be increased, and furthermore, the melting rate can be increased. The density of the molten resin in the cavity can be made uniform while the supply of the resin is substantially free of pressure. .

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of an insert molding apparatus according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of a main part when a resin is supplied in an insert molding apparatus according to a second embodiment of the present invention.

FIG. 3 is a vertical sectional view of a main part of the insert molding apparatus shown in FIG. 2 at the time of pressurization.

FIG. 4 is an enlarged perspective view of a primary molded product molded by the insert molding device shown in FIG.

5 is an enlarged perspective view of an automobile part as a secondary molded product molded by the insert molding device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insert molding apparatus 3 Automobile part 5 Primary molded article (of an automobile part) 7 Gas detection element (of a primary molded article) 9 Body (of a primary molded article) 11 Gas entrance path (of a primary molded article) 13 (of a primary molded article) ) Gas Entry Path 15 Main Body (of Auto Parts) 17 Protrusion (of Main Body) 19 Outward Gas Entry Path (of Main Body) 21 Outward Gas Entry Path (of Main Body) 23 Mold 25 Injection Mechanism 27 Contents Object removal mechanism 29 (Mold) fixed mold 31 (Mold) movable mold 33 (Mould) cavity 35 (Mould) split surface 37 (Mould) component mounting block 39 (Mould) gas Injection path forming projection 41 (Mold) Gas inflow path forming projection 43 (Mold) slide pin 45 Fixed die plate 47 Torpedo 49 Heating cylinder 51 Injection plunger 53 Moving die plate 55 Cylinder mounting plate 57 Guide pin 59 Housing 61 Plunger drive unit 63 Cylinder chamber 65 Continuous sleeve 67 Plunger 69 (Movable) base unit 71 (Continuous sleeve) hole 73 (Housing) discharge hole 75 Control unit 77 Heater 79 Eject plate 81 Eject pin 83 Insert molding device 85 Base plate 87 Resin tank 89 Pressurizing chamber 91 Die 93 Base block (of mold) 95 Depressed concave part (of mold) 97 Cavity 99 of mold Recess (of cavity) 101 Upper surface of (cavity) 103 Gas inlet path forming pin (of mold) 105 Gas inlet path forming pin (of mold) 107 Guide hole (of mold) 109 Cylinder placement space (of mold) 111 (Mold) Eject mechanism placement space 13 Guide hole (of mold) 115 Eject pin (of mold) 117 Side wall 119 Insertion hole of (side wall) 121 Internal space (of resin tank) 123 Nozzle 125 Top wall (of resin tank) 127 Molten resin 129 (pressurization) Internal space of the chamber 131 Pressure plate 133 Piston rod

Claims (2)

[Claims] 1. An insert molding apparatus for insert-molding a fragile insert part together with a required body with a synthetic resin, said molten resin supply means supplying molten resin into a cavity in which said insert part is removably mounted. And a content extracting means for extracting the content of the cavity, and substantially in synchronization with the supply of the molten resin, the content of the cavity having substantially the same volume as the supplied molten resin is extracted outside the cavity. Features insert molding equipment. 2. A resin tank for storing a molten resin, a pressurizing chamber provided with a pressurizing means, a fragile insert part having an open upper surface, or a primary molded article comprising a fragile insert part held by a synthetic resin. A mold having a cavity that is removably mounted, and a mold that is movably provided between the resin tank and the pressurizing chamber, wherein the mold is immersed in a resin tank in which molten resin is stored. An insert molding apparatus wherein the molten resin in the cavity is pressurized in the pressurizing chamber after the molten resin is poured into the cavity.