JP7094912B2 - Manufacturing method of injection molded products, mold equipment for molding injection molded products - Google Patents

Description

The present invention relates to a method for manufacturing an injection-molded product in which an insert material is embedded inside a coating resin made of a thermoplastic resin, and a mold device for molding an injection-molded product.

Conventionally, the insert molding method, which is a kind of method for manufacturing an injection molded product, is well known. The injection-molded product manufactured by the insert molding method has a structure in which an insert material is embedded inside a coating resin made of a thermoplastic resin. Specific examples of the injection-molded article manufactured by such a method include an in-vehicle electronic component obtained by embedding a bus bar made of a conductive metal as an insert material inside a coating resin.

As a mold device for manufacturing an injection-molded product by an insert molding method, a mold device provided with an insert material support mechanism for supporting the insert material at the time of molding has been conventionally proposed (see, for example, Patent Document 1). The upper and lower molds in this mold device are separable from each other and are configured to form a cavity into which the thermoplastic resin is injected when the mold is closed. The insert material support mechanism is provided on at least one of the upper mold and the lower mold, and has a structure in which a support pin capable of supporting the insert material is projected from the tip surface of the core portion which is the main body portion.

Then, in insert molding using such a mold device, first, the insert material is set between the upper mold and the lower mold and the mold is closed. At that time, the insert material is supported and fixed in the cavity by bringing the tip surface of the support pin into contact with the insert material. In this state, a resin filling step of filling the cavity with the molten thermoplastic resin is performed. Specifically, the molten thermoplastic resin is injected into the cavity and then cooled through holding pressure to solidify the thermoplastic resin. At this time, due to the action of the resin pressure, the support pin and the core portion move backward as one unit, and the thermoplastic resin enters the gap. As a result, the insert material is embedded inside the coating resin made of thermoplastic resin, and an injection-molded product in which the insert material is not exposed at the portion supported by the support pin is manufactured.

Japanese Unexamined Patent Publication No. 2004-216855

However, the method for manufacturing an injection-molded product using the conventional mold device has the following problems.

That is, in the insert material support mechanism in the conventional mold apparatus, the area of the tip surface of the support pin is small and it is difficult for the resin pressure to sufficiently act on the insert material support mechanism, so that the support pin cannot be stably moved backward. Therefore, there is a concern that the wall thickness of the coating resin at the portion supported by the support pin may vary.

In addition, if a step is provided on the outer peripheral portion of the tip surface of the support pin in order to smoothly retract the support pin by the resin pressure, a dent mark of the support pin remains on the surface of the molded product, and the wall thickness is locally thin. turn into. In this case, it is necessary to pot with resin to fill the dent, which causes complicated work and cost increase.

The present invention has been made in view of the above problems, and an object thereof is to embed an insert material inside a coating resin by stable operation of the support pin without causing a dent of the support pin on the surface of the molded product. It is an object of the present invention to provide a method for manufacturing an injection-molded product, and a mold device for molding an injection-molded product.

In order to solve the above problems, the invention described in the means 1 is used in manufacturing an injection molded product in which an insert material is embedded inside a coating resin made of a thermoplastic resin, and the thermoplastic resin is injected. A mold member having an inner surface for forming the cavity and an insert material support mechanism for supporting the insert material in the cavity are provided, and the insert material support mechanism has a first tip surface which is a surface forming the cavity. It has a main body portion and a support pin that is inserted into a pin support hole opened at the first tip surface of the main body portion so as to support the insert material at the second tip surface, and has the main body portion and the support pin. The support pin can move between the forward position and the backward position independently of each other in the mold opening / closing direction based on the drive action of the drive body, and the drive body moves the main body portion and the support pin in the forward direction, respectively. The load of the spring that urges the support pin is set to be smaller than the pressure of the thermoplastic resin, and the load of the spring that urges the main body portion urges the support pin. When the main body portion and the support pin are both in the forward position, the second tip surface is in a state of protruding from the first tip surface, and the main body portion and the support pin are set to be smaller than the load of the spring. Is a method for manufacturing an injection-molded article by a mold device in which the second tip surface is in the same plane as the first tip surface when both are in the retracted position, and the insert material is set. The mold member is closed to form the cavity, and both the main body and the support pin are moved to the forward position to support the insert material on the second tip surface of the support pin. The main body portion is included in the injection process in the resin filling step, which includes a step and a resin filling step of filling the cavity with the molten thermoplastic resin, without immersing the support pin in the pin support hole. The second tip surface is moved in the retracting direction together with the support pin, and in the pressure holding process following the injection process, the main body portion is moved in the retracting direction and the support pin is immersed in the pin support hole. The gist thereof is a method for manufacturing an injection-molded article, which is characterized in that it belongs to the same plane as the first tip surface.

Therefore, according to the invention described in the means 1, when the molten thermoplastic resin is injected into the cavity in the resin filling step, the pressure of the resin first acts on the main body portion to move the main body portion in the retracting direction. Start. Then, the support pin moves in the retracting direction in conjunction with the movement of the main body in the retracting direction. As a result, a gap is created between the insert material and the support pin, the resin enters the gap, and the pressure of the resin acts on the entire second tip surface of the support pin. At the forward position, the second tip surface, which is in contact with the insert material and is difficult for the pressure of the resin to act on, is exposed, and the pressure of the resin acts on the support pin so that the support pin smoothly retracts and sinks into the pin support hole. The second tip surface belongs to the same plane as the first tip surface. Therefore, the resin can be cooled and solidified while keeping the first tip surface and the second tip surface forming the cavity flat. Therefore, the insert material can be embedded inside the coating resin by the stable operation of the support pin without causing the support pin to be dented on the surface of the molded product . In addition, by using a spring as the drive body and setting the magnitude relationship of the spring load as described above, a relatively simple mold structure can be used without applying a driving force from the outside by a hydraulic cylinder, a motor, an actuator, or the like. The desired operation can be performed by the insert material support mechanism.

In the invention described in the means 2, in the means 1, the pressure of the molten thermoplastic resin is applied to the first tip surface to move the main body portion in the receding direction, and the pressure is applied to the second tip surface. The gist is that the support pin is immersed in the pin support hole by acting on the tip surface.

Therefore, according to the invention described in the means 2, the following actions and effects are further exerted in addition to the actions and effects of the means 1. That is, since the main body and the support pin can be moved in the retracting direction by using the pressure of the molten thermoplastic resin, it is not necessary to provide a means for actively retracting these members in the drive body, and the mold structure can be formed. Can be simplified.

According to the invention described in the means 3, in the means 1 or 2, in the resin filling step, the engaging portion provided on the main body portion engages with the engaged portion provided on the support pin. The gist is to move the main body portion in the retracting direction and the support pin in the retracting direction.

Therefore, according to the invention described in the means 3, the following actions and effects are further exerted in addition to the actions and effects of the means 1 and the like. That is, since the driving force acting on the main body due to the engagement between the main body and the support pin also acts on the support pin, the support pin can be moved in the retracting direction with a relatively simple structure.

According to the invention described in the means 4, in any one of the means 1 to 3, the support pin has a structure in which two or more pin main bodies are connected by a common connecting portion, and is provided in one main body portion. The gist is that two or more pin bodies retract at the same time.

Therefore, according to the invention described in the means 4, the following actions and effects are further exerted in addition to the actions and effects of the means 1 and the like. That is, the movements of the two or more pin bodies in the retracting direction can be interlocked with each other, and the movement of each pin body is stabilized. In addition, the mold structure can be simplified.

In the invention described in the means 5, in any one of the means 1 to 4, in the resin filling step, the first tip surface and the second tip surface belong to the same plane as the inner surface of the mold member. The gist is that.

Therefore, according to the invention described in the means 5, the following actions and effects are further exerted in addition to the actions and effects of the means 1 and the like. That is, since the injection-molded product does not have a convex portion (thick portion of the resin) due to the recession of the main body portion, the injection-molded product can be miniaturized.

The invention described in means 6 is used in manufacturing an injection-molded article in which an insert material is embedded inside a coating resin made of a thermoplastic resin, and has an inner surface forming a cavity into which the thermoplastic resin is injected. A mold device including a mold member and an insert material support mechanism for supporting the insert material in the cavity, wherein the insert material support mechanism is a main body having a first tip surface which is a surface forming the cavity. It has a portion and a support pin that is inserted into a pin support hole opened at the first tip surface of the main body portion so as to support the insert material at the second tip surface, and has the main body portion and the support. The pin can move between the forward position and the backward position independently of each other in the mold opening / closing direction based on the drive action of the drive body, and the drive body attaches the main body portion and the support pin in the forward direction, respectively. The load of the spring that urges the support pin is set to be smaller than the pressure of the thermoplastic resin, and the load of the spring that urges the main body portion is the spring that urges the support pin. When the main body portion and the support pin are both in the forward position, the second tip surface is in a state of protruding from the first tip surface, and the main body portion and the support pin are both set to be smaller than the load of. The gist thereof is a mold device for molding an injection-molded article, characterized in that the second tip surface belongs to the same plane as the first tip surface when it is in the retracted position.

Therefore, according to the invention described in the means 6, when the molten thermoplastic resin is injected into the cavity, the pressure of the resin first acts on the main body portion, and the main body portion starts to move in the retracting direction. Then, the support pin moves in the retracting direction in conjunction with the movement of the main body in the retracting direction. As a result, a gap is created between the insert material and the support pin, the resin enters the gap, and the pressure of the resin acts on the entire second tip surface of the support pin. When the pressure of the resin acts, the support pin smoothly retracts and sinks into the pin support hole, so that the second tip surface belongs to the same plane as the first tip surface. Therefore, the resin can be cooled and solidified while keeping the first tip surface and the second tip surface forming the cavity flat. Therefore, the insert material can be embedded inside the coating resin by the stable operation of the support pin without causing the support pin to be dented on the surface of the molded product . In addition, by using a spring as the drive body and setting the magnitude relationship of the spring load as described above, a relatively simple mold structure can be used without applying a driving force from the outside by a hydraulic cylinder, a motor, an actuator, or the like. The desired operation can be performed by the insert material support mechanism.

The gist of the invention described in the means 7 is that, in the means 6 , the spring for urging the support pin in the forward direction is housed inside the main body portion.

Therefore, according to the invention described in the means 7 , the following actions and effects are further exerted in addition to the actions and effects of the means 6 . That is, the movable distance between the main body and the support pin can be set individually.

According to the invention described in the means 8 , in the means 6 or 7 , the main body portion is provided with a stopper portion that regulates the immersion operation of the support pin so that the second tip surface does not recede from the first tip surface. The gist is that it is done.

Therefore, according to the invention described in the means 8 , in addition to the action and effect of the means 6 and the like, the following actions and effects are further exerted. That is, since the support pin does not retreat too much, it is possible to prevent the protrusion from being generated on the surface of the molded product.

As described in detail above, according to the inventions of claims 1 to 8 , the insert material is embedded inside the coating resin by the stable operation of the support pins without causing the dents of the support pins on the surface of the molded product. can do.

(A) is a front view of an injection molded product manufactured by using the mold apparatus of the embodiment embodying the present invention, and (b) is a side view thereof. Schematic cross-sectional view of the mold apparatus of the embodiment. The schematic sectional drawing which shows the state of the molding preparation process of the insert material support mechanism of an embodiment. The schematic sectional view which shows the state of the injection process in the resin filling process of the insert material support mechanism. The schematic sectional view which shows the state of the injection process in the resin filling process of the insert material support mechanism. The schematic cross-sectional view which shows the state of the pressure holding process in the resin filling process of the insert material support mechanism. Schematic cross-sectional view of an insert material support mechanism in a mold device of another embodiment. Schematic cross-sectional view of an insert material support mechanism in a mold device of another embodiment. (A) is a partial schematic perspective view of the insert material support mechanism in the mold device of the embodiment, and (b) to (d) are partial schematic perspective views of the insert material support mechanism in the mold device of another embodiment. Schematic cross-sectional view of the mold device of another embodiment.

Hereinafter, a mold device for molding an injection-molded product and a method for manufacturing an injection-molded product according to an embodiment embodying the present invention will be described in detail with reference to FIGS. 1 to 6.

1 (a) and 1 (b) show an injection-molded article 1 manufactured by using the mold apparatus 11 of the present embodiment. This injection-molded product 1 is an insert-molded product manufactured through an insert molding method, which is a kind of injection molding method, and has a structure in which an insert material 2 is embedded inside a coating resin 3 made of a thermoplastic resin. There is. The thermoplastic resin that is the material for forming the coating resin 3 is not particularly limited, and for example, PPS resin, PBT resin, or the like is used. Inorganic substances such as glass fibers and glass grains may be added as fillers to these resin materials in order to reduce the coefficient of thermal expansion. As the insert material 2, any material can be selected as long as it is a structure previously formed of a material different from the resin material used in the coating resin 3, without any particular limitation on the material, shape, and the like. .. In this embodiment, a flat plate-shaped bus bar made of a conductive metal material is used as the insert material 2. The insert material 2 is provided with terminal portions 2a having bolt holes 2b at both ends thereof. These terminal portions 2a are not embedded in the coating resin 3 and are exposed to the outside.

Next, the mold device 11 for manufacturing the injection-molded article 1 having the above structure will be described. FIG. 2 is a schematic cross-sectional view of the mold device 11, and FIG. 3 is a schematic cross-sectional view showing the insert material support mechanism 41 thereof.

As shown in FIGS. 2 and 3, the mold apparatus 11 includes an upper mold 20 (first mold), a lower mold 30 (second mold), and a plurality of insert material support mechanisms 41. In these drawings, the insert material support mechanism 41 is drawn larger than the actual mold device 11 for easy understanding.

The lower mold 30, which is a movable type, is attached to a movable plate of an injection molding machine (not shown). An inner surface 32, which is a surface forming the cavity C1, is provided at a predetermined position on the upper surface 31 of the lower mold 30. The upper mold 20 which is a fixed mold is attached to a fixed plate of an injection molding machine (not shown). An inner surface 22 which is a surface forming the cavity C1 is provided at a predetermined position on the lower surface 21 of the upper die 20. The upper mold 20 is arranged above the lower mold 30, and the inner surface 22 of the upper mold 20 and the inner surface 32 of the lower mold 30 face each other. In the case of the mold device 11 of the present embodiment, by driving the lower mold 30 in the mold opening / closing direction (vertical direction in FIG. 2), the upper mold 20 and the lower mold 30 can be brought close to each other and separated from each other. There is.

As shown in FIG. 2, in the case of the mold device 11 of this embodiment, the upper mold 20 is provided with one support mechanism mounting hole 23, and the lower mold 30 is provided with two support mechanism mounting holes 33. .. An insert material support mechanism 41 is attached to each of the support mechanism mounting holes 23 and 33, respectively. That is, the mold device 11 includes a total of three insert material support mechanisms 41. The insert material support mechanism 41 provided in the upper mold 20 abuts on the substantially central portion on the upper surface side of the insert material 2 to support the insert material 2 from above. The two insert material support mechanisms 41 provided in the lower mold 30 abut on the lower surface side of the insert material 2 at positions separated from each other, and support the insert material 2 at two points from the lower side.

As shown in FIG. 3 and the like, the insert material support mechanism 41 of the present embodiment is composed of a main body portion 42, a support pin 43, a base portion 45, springs 51, 52, a closing member 44, and the like.

The main body portion 42 has a body portion 42b having a circular cross section and a flange portion 42c integrally formed at the lower end of the body portion 42b. The upper surface of the main body 42 shown in FIG. 3 is a flat first tip surface 42a, and this first tip surface 42a forms a cavity C1 together with the inner surface 22 of the upper mold 20 and the inner surface 32 of the lower mold 30. It is designed to do. A pin support hole 47 having a circular cross section opened at the first front end surface 42a is formed through the central portion of the body portion 42b. The opening on the lower end side of the pin support hole 47 has an enlarged diameter, and the step created by the enlarged diameter is the engaging portion 42d. The support mechanism mounting hole 33 in the lower mold 30 has a large diameter portion, a medium diameter portion, and a small diameter portion in this order from the inlet side, and the main body portion 42 is slidable to the medium diameter portion and the small diameter portion. It is contained. The first tip surface 42a of the main body 42 may have a size (diameter, width) larger than that of the insert material 2.

The support pin 43 includes a pin body 43b, which is a rod-shaped portion having a circular cross section, and an engaged portion 43c, which is a large-diameter portion integrally formed at the base end portion thereof, and is provided on the tip end side of the pin body 43b. Is a flat second tip surface 43a, which is a portion that supports the insert material 2. The support pin 43 having such a structure is inserted into the pin support hole 47 opened at the first tip surface 42a of the main body portion 42 so as to be able to appear and disappear. Further, the first tip surface 42a and the second tip surface 43a are set so as to face each other in parallel with the surface of the insert material 2 when the mold is closed. Therefore, when the insert material 2 is tilted with respect to the mold opening / closing direction, it is preferable that the first tip surface 42a and the second tip surface 43a are also tilted. The engaged portion 43c provided on the support pin 43 is configured to be able to be engaged with the engaging portion 42d provided on the main body portion 42.

A base portion 45 is provided on the lower end surface of the main body portion 42. The base portion 45 is fixed to the main body portion 42 by using a fastening means 46 such as a screw or a bolt. Inside the spring accommodating space formed by the main body portion 42 and the base portion 45, a spring 52 as a driving body for driving the support pin 43 is accommodated in a compressed state. One end of the spring 52 is in contact with the base end surface of the support pin 43, and the other end is in contact with the bottom surface of the recess provided in the center of the upper surface of the base portion 45. As a result, the urging force of the spring 52 always acts in the direction of advancing the support pin 43 (protruding from the first tip surface 42a).

Further, the base portion 45 also serves as a stopper portion for restricting the immersion operation of the support pin 43 so that the second tip surface 43a of the support pin 43 does not recede from the first tip surface 42a of the main body portion 42. That is, when the outer peripheral portion of the base end surface of the support pin 43 comes into contact with the stepped portion 45a on the upper surface of the base portion 45, the movement of the support pin 43 in the retracting direction is stopped.

The closing member 44 is a bottomed cylindrical member, and is mounted and fixed to a large diameter portion of the support mechanism mounting holes 33 in the lower mold 30. The method of mounting and fixing the closing member 44 is not limited, but may be detachably screwed to, for example, the large diameter portion of the support mechanism mounting hole 33. The closing member 44 has a recess that opens on the upper surface side, and the base portion 45 is slidably housed in the recess. Inside the spring accommodating space formed by the base portion 45 and the closing member 44, the spring 51 as a driving body for driving the main body portion 42 is accommodated in a compressed state. One end of the spring 51 is in contact with the central portion of the lower surface of the base portion 45, and the other end is in contact with the central portion of the inner bottom surface of the concave portion of the closing member 44. As a result, the urging force of the spring 51 always acts in the direction of advancing the main body portion 42. That is, in the present embodiment, the main body 42 and the support pin 43 are configured to be movable between the forward position and the backward position independently of each other in the mold opening / closing direction based on the driving action of the springs 51 and 52 which are the driving bodies. Has been done. The position where the main body 42 and the support pin 43 are most advanced in the closed state is referred to as the "advanced position", and the position where the main body 42 and the support pin 43 are most retracted is referred to as the "retracted position".

Here, the load PA of the spring 52 that urges the support pin 43 is set to retreat due to the pressure of the thermoplastic resin R1 in the resin filling step. Further, the load PC of the spring 51 that urges the main body 42 is set to be smaller than the load PA of the spring 52 that urges the support pin 43. That is, a magnitude relationship of "PC <PA" is set between them. Further, in the state where the mold is closed and the cavity C1 is not filled with the thermoplastic resin R1, only the load PA of the spring 52 acts on the support pin 43, and only the load PC of the spring 51 acts on the main body 42. It works. Further, the main body portion 42 and the support pin 43 are in a state in which the second tip surface 43a protrudes from the first tip surface 42a (see FIG. 3).

Further, the closing member 44 is a stopper portion that restricts the backward movement of the main body portion 42 so that the first tip surface 42a of the main body portion 42 does not retract from the inner surfaces 22 and 32 that form the cavity C1. It also plays a role as. That is, when the outer peripheral portion of the base end surface of the main body portion 42 comes into contact with the upper edge portion 44a of the closing member 44, the movement of the main body portion 42 in the retracting direction is stopped. At this time, the first tip surface 42a is in a state of belonging to the same plane as the inner surfaces 22 and 32.

Next, a procedure for manufacturing the injection-molded product 1 using the injection-molding mold device 11 configured as described above will be described.

First, the upper mold 20 and the lower mold 30 are opened, and the insert material 2 is set in the work mounting area in the lower mold 30. At this time, the first tip surface 42a protrudes from the inner surfaces 22 and 32 around the first tip surface 42a, and the second tip surface 43a protrudes from the first tip surface 42a (see FIG. 3). Then, the upper mold 20 and the lower mold 30 are closed to form the cavity C1, and the insert material 2 is floated in the cavity C1 by bringing each second tip surface 43a into contact with the insert material 2. Support with (molding preparation process). At this time, the main body 42 and the support pin 43 of each insert material support mechanism 41 are both in the forward position.

In the subsequent resin filling step, the molten thermoplastic resin R1 is injected into the cavity C1 through a gate portion (not shown) provided in either the upper mold 20 or the lower mold 30. When the resin pressure is still low in the injection process immediately after the start of the resin filling process, both the main body portion 42 and the support pin 43 are maintained in the forward position (see FIG. 4). Therefore, at this point, the second tip surface 43a is still in contact with the insert material 2. When the resin pressure rises in the injection process, the main body 42 is first pressed and starts moving in the backward direction. Then, the support pin 43 moves in the retracting direction together with the main body portion 42 due to the engaging relationship between the engaging portion 42d and the engaged portion 43c (see FIG. 5). As a result, the second tip surface 43a is separated from the insert material 2, a gap S1 is formed between the two, and the molten thermoplastic resin R1 enters the gap S1. At this time, the resin pressure also acts on the second tip surface 43a, and the support pin 43 is in a state where it can be retracted by the resin pressure. When the pressure holding process is reached through the injection process, the main body portion 42 pressed in the receding direction comes into contact with the closing member 44, and the main body portion 42 is in a state where the first tip surface 42a belongs to the same plane as the inner surfaces 22 and 32. Stops. On the other hand, the support pin 43 moves in the immersion direction (backward direction) (see FIG. 6). Finally, both the main body portion 42 and the support pin 43 are moved to the retracted position. Then, after holding this state for a certain period of time in the pressure holding process, the thermoplastic resin R1 is cooled and solidified in the subsequent cooling step. After that, the upper mold 20 and the lower mold 30 are opened and the injection-molded product 1 is taken out, thereby completing a series of manufacturing procedures. As a result of the above, the desired injection-molded article 1 of FIG. 1 can be manufactured.

Then, according to this embodiment, the following effects can be obtained.

(1) In the injection molding die device 11 of the present embodiment and the manufacturing method using the same, as described above, the thermoplastic resin R1 melted in the cavity C1 is formed in the injection process immediately after the start of the resin filling step. When ejected, the support pin 43 moves in the retracting direction in conjunction with the movement of the main body 42 in the retracting direction. As a result, a gap is created between the insert material 2 and the support pin 43, and the thermoplastic resin R1 enters the gap, and the resin pressure also acts on the second tip surface 43a of the support pin 43. Further, due to the action of the resin pressure, the support pin 43 smoothly retracts and immerses in the pin support hole 47, so that the second tip surface 43a belongs to the same plane as the first tip surface 42a. Therefore, the thermoplastic resin R1 can be cooled and solidified while keeping the first tip surface 42a and the second tip surface 43a forming the cavity C1 flat, and the coating resin 3 having a suitable shape can be formed. Therefore, a predetermined portion of the insert material 2 can be embedded inside the coating resin 3 by the stable operation of the support pin 43 without causing a dent of the support pin 43 on the surface of the molded product. Therefore, it is not necessary to fill (pot) the dent of the support pin 43 with a resin such as an adhesive after molding, and it becomes easy to avoid complicated work and cost increase. Further, in the present embodiment, since there is no local difference in wall thickness due to the dent of the support pin 43 on the surface of the molded product, problems such as insufficient insulation distance and foreign matter adhering to the dent are solved. Will be done.

(2) In the present embodiment, a spring 51 that urges the main body 42 in the forward direction and a spring 52 that urges the support pin 43 in the forward direction are used as driving bodies. Then, the resin pressure of the molten thermoplastic resin R1 is applied to the first tip surface 42a to move the main body portion 42 in the receding direction. Further, by applying the resin pressure to the second tip surface 43a, the support pin 43 is immersed in the pin support hole 47. That is, as a result of adopting the drive body as described above, the main body portion 42 and the support pin 43 can be moved in the retracting direction by utilizing the resin pressure. Therefore, it is not necessary to provide the drive body with means for actively retracting the main body portion 42 and the support pin 43, and the mold structure can be simplified.

(3) In the present embodiment, a magnitude relationship of "PC <PA" is set between the load PA of the spring 52 that urges the support pin 43 and the load PC of the spring 51 that urges the main body 42. .. By setting in this way, the insert material support mechanism 41 can be made to perform a desired operation with a relatively simple mold structure without applying a driving force from the outside by a hydraulic cylinder, a motor, an actuator or the like.

(4) In the present embodiment, in the injection process, the engaging portion 42d provided in the main body portion 42 engages with the engaged portion 43c provided in the support pin 43 when moving in the backward direction. It is configured. Therefore, since the spring force acting on the main body portion 42 also acts on the support pin 43, the support pin 43 having a smaller pressure receiving area than the main body portion 42 can be easily moved in the retracting direction with a relatively simple structure.

(5) In the present embodiment, in the resin filling step, the first tip surface 42a and the second tip surface 43a are flush with the inner surfaces 22 and 32 of the upper mold 20 and the lower mold 30 which are the surfaces forming the cavity C1. It becomes a state to belong to. Therefore, the injection-molded product 1 does not have a convex portion (thick portion of the resin) due to the step between the main body portion 42 and the support pin 43, and the thickness of the resin in that portion becomes uniform. Can be miniaturized.

(6) In the present embodiment, the spring 52 that urges the support pin 43 in the forward direction is housed inside the main body portion 42. Therefore, the movable distance between the main body portion 42 and the support pin 43 can be set individually.

(7) In the present embodiment, the main body portion 42 is provided with a base portion 45 that functions as a stopper portion that regulates the immersion operation of the support pin 43 so that the second tip surface 43a does not recede from the first tip surface 42a. Has been done. Therefore, since the support pin 43 does not retreat too much, it is possible to prevent the protrusion from being generated on the surface of the molded product.

Each embodiment of the present invention can be arbitrarily modified without departing from the spirit of the invention.

It may be configured like the mold apparatus 11A of another embodiment shown in FIG. 7. In the insert material support mechanism 41A of the mold device 11A, instead of omitting the base portion 45, a stopper portion 63 smaller than the base portion 45 is attached. Further, the mold device 11A includes two springs 61 that urge the main body 42 in the forward direction, and one spring 62 that urges the support pin 43 in the forward direction. Both of these springs 61 and 62, which are driving bodies, are housed in the spring accommodating space formed by the main body portion 42 and the closing member 44. Therefore, the spring 62 is not housed inside the main body 42. This configuration has an advantage that maintenance work such as replacement of springs 61 and 62 can be easily performed.

In the above embodiment, the support pin 43 has one pin body 43b, but the number of pin bodies 43b may be two or more. For example, as in the mold device 11B of another embodiment shown in FIG. 8, a support pin 43B having a structure in which two pin main bodies 43b are connected by a common connecting portion 43e may be adopted. According to this configuration, the two pin main bodies 43b provided in one main body 42 can be retracted at the same time in conjunction with each other, and the movement of each pin main body 43b is stabilized. In addition, the mold structure can be simplified.

In the insert material support mechanism 41 of the above embodiment, as shown in FIG. 9A, the main body portion 42 has a circular cross section, and one pin support opened by the first tip surface 42a having the circular shape. One pin body 43b was supported in the hole 47. Further, in the insert material support mechanism 41B of another embodiment shown in FIG. 8, the main body portion 42 has a circular cross section as shown in FIG. 9B, and the first tip surface 42a having the circular shape thereof. The two pin main bodies 43b were supported in the two pin support holes 47 opened in. However, the shape of the main body, the number of pin main bodies, the arrangement, etc. are not limited to these, and can be appropriately set depending on the shape and arrangement of the injection molded product and the insert material, the relationship with other metal parts, and the like. .. For example, in the insert material support mechanism 41C of another embodiment shown in FIG. 9C, a support pin 43C having a structure in which four pin main bodies 43b are connected by a common connecting portion (not shown) is adopted. The support pin 43C is housed in the main body portion 42 having a square cross section. The four pin bodies 43b are each supported by four pin support holes 47 opened by the rectangular first tip surface 42a. Further, in the insert material support mechanism 41D of another embodiment shown in FIG. 9D, a support pin 43D having a structure in which eight pin main bodies 43b are connected by a common connecting portion (not shown) is adopted. The support pin 43D is housed in the main body portion 42 having a rectangular cross section. In the rectangular first tip surface 42a, eight pin support holes 47 are arranged in a row, and eight pin main bodies 43b are supported in each pin support hole 47. It is preferable that the corner of the rectangle is an R surface (chamfered) because it is easy to move.

In the above embodiment, the insert material support mechanism 41 is provided on both the upper mold 20 and the lower mold 30, but it may be provided on only one of them. Alternatively, the insert material support mechanism 41 may be provided on a mold member different from the upper mold 20 and the lower mold 30. For example, in the mold apparatus 11C of another embodiment shown in FIG. 10, a structure in which an insert material support mechanism 41 is provided in a pair of slide molds 70 arranged between the upper mold 20 and the lower mold 30 is adopted. There is. These slide molds 70 are provided with a resin coating 3 and a cavity C1 for forming a wall portion 3a protruding from the resin coating 3 in the movable direction of the slide mold 70. Further, the slide type 70 is provided with an inner surface 71 which is a surface forming the cavity C1 and is provided with a support mechanism mounting hole 73 which is opened at the inner surface 71. The insert material support mechanism 41 is attached to the support mechanism mounting hole 73. In this mold device 11C, a crank-shaped insert material 2A having two bent portions is set vertically. At this time, both the left and right sides of the insert material 2A are supported by the support pins 43 of the respective insert material support mechanisms 41. By performing injection molding in this state, an injection molded product 1A having a desired shape as shown in FIG. 10 is manufactured.

In the above embodiment, as shown in FIG. 1, the position of the insert material support mechanism 41 on the upper mold 20 side and the position of the insert material support mechanism 41 on the lower mold 30 side are shifted so as not to face each other. However, the present invention is not limited to this, and the insert material support mechanisms 41 may be arranged so as to face each other.

The insert material support mechanism 41 of the above embodiment does not particularly have a mechanism for adjusting the load of the spring that urges the support pin 43, but a spring load adjustment mechanism having a function of changing the degree of compression of the spring is provided. The load of the spring may be adjusted as appropriate. According to this configuration, the load of the spring can be finely adjusted according to the desired shape and type of the injection molded product.

For example, in the mold device 11 of the above embodiment provided with a plurality of insert material support mechanisms 41 at different positions, the spring load of the insert material support mechanism 41 is set to be equal regardless of the distance from the gate portion. Not limited to this. For example, considering the difference in distance from the gate portion, the spring load of the insert material support mechanism 41 located far from the gate portion is relative to the spring load of the insert material support mechanism 41 located near the gate portion. It may be set small to. That is, in general, the resin pressure may be low at a position far from the gate portion, and by appropriately setting the spring load in consideration of this, the insert material support mechanism 41 at a plurality of different positions can be stabilized. Can be operated as a target.

Next, in addition to the technical ideas described in the claims, the technical ideas grasped by each of the above-described embodiments are listed below.

(1) The mold members are an upper mold and a lower mold that are separated from each other, and the insert material support mechanism is provided in at least one of the upper mold and the lower mold. According to this, the main body and the support pin can be moved back and forth in the mold opening / closing direction (vertical direction) independently of each other.
(2) The mold member is a slide type arranged between an upper mold and a lower mold that are in contact with each other, and the insert material support mechanism is provided in the slide mold. According to this, the main body and the support pin can be moved back and forth independently of each other in the direction orthogonal to the mold opening / closing direction (horizontal direction).
(3) The insert material is a bus bar.
(4) The insert material support mechanism is provided with a spring load adjusting mechanism for adjusting the load of the spring that urges the support pin. According to this, the load of the spring can be finely adjusted according to the type of the desired molded product and the like.
(5) A plurality of the insert material support mechanisms are provided in the mold member provided with a gate portion for introducing the molten thermoplastic resin into the cavity, and the insert material support mechanism located at a position far from the gate portion. The spring load of the insert material is set to be relatively smaller than the spring load of the insert material support mechanism located near the gate portion. According to this, the resin pressure may generally be low at a position far from the gate, so by appropriately setting the spring load in consideration of this, the insert material support mechanisms at different positions can be set. It can be operated stably.

1, 1A ... Injection-molded product 2, 2A ... Insert material 3 ... Coating resin 11, 11A, 11B, 11C ... Mold device 20 ... Upper mold 22, 32, 71 ... (of the mold member) inner surface 30 ... Lower molds 41, 41A, 41B, 41C, 41D as mold members ... Insert material support mechanism 42 ... Main body portion 42a ... First tip surface 42d ... Engagement portion 43 ... Support pin 43a ... Second tip surface 43b ... Pin body 43c ... Engaged portion 43e ... (also serving as an engaged portion) Connecting portion 45 ... Base portion 47 that also serves as a stopper portion ... Pin support holes 51, 52, 61, 62 ... Spring 63 as a driving body ... Stopper portion 70 ... Type Slide type C1 as a member ... Cavity R1 ... Thermoplastic resin S1 ... Gap

Claims (8)

Used when manufacturing an injection-molded product in which an insert material is embedded inside a coating resin made of a thermoplastic resin, a mold member having an inner surface forming a cavity into which the thermoplastic resin is injected, and a mold member in the cavity. The insert material support mechanism is provided with an insert material support mechanism for supporting the insert material, and the insert material support mechanism has a main body portion having a first tip surface which is a surface forming the cavity and the first tip surface of the main body portion. It is inserted into a pin support hole that opens so that it can appear and disappear, and has a support pin that supports the insert material on the second tip surface, and the main body and the support pin are in the mold opening / closing direction based on the drive action of the drive body. The drive body is a spring that urges the main body and the support pin in the forward direction, and is a spring that urges the support pin. The load of the main body is set to be smaller than the pressure of the thermoplastic resin, and the load of the spring for urging the main body is set to be smaller than the load of the spring for urging the support pin. When both the pins are in the forward position, the second tip surface is in a state of protruding from the first tip surface, and when both the main body and the support pin are in the retracted position, the second tip surface is said. It is a method of manufacturing an injection-molded product by a mold device that belongs to the same plane as the first tip surface.
With the insert material set, the mold member is closed to form the cavity, and both the main body and the support pin are moved to the forward position so that the second tip surface of the support pin is used. The molding preparation process that supports the insert material and
Including a resin filling step of filling the cavity with the molten thermoplastic resin.
In the injection process in the resin filling step, the main body portion is moved in the retracting direction together with the support pin without the support pin being immersed in the pin support hole.
In the pressure holding process following the injection process, the main body portion is moved in the retracting direction and the support pin is immersed in the pin support hole so that the second tip surface belongs to the same plane as the first tip surface. A method for manufacturing an injection-molded product, which is characterized by being in a state. By applying the pressure of the melted thermoplastic resin to the first tip surface, the main body portion is moved in the receding direction, and at the same time, the main body portion is moved in the receding direction.
The method for manufacturing an injection-molded article according to claim 1, wherein the support pin is immersed in the pin support hole by applying the pressure to the second tip surface. In the injection process, the engaging portion provided on the main body portion engages with the engaged portion provided on the support pin, so that the main body portion moves in the retracting direction together with the support pin. The method for manufacturing an injection-molded article according to claim 1 or 2. The support pin has a structure in which two or more pin main bodies are connected by a common connecting portion, and the two or more pin main bodies provided in one main body portion retract at the same time. The method for manufacturing an injection-molded article according to any one of 3 to 3. The invention according to any one of claims 1 to 4, wherein in the pressure holding process, the first tip surface and the second tip surface belong to the same plane as the inner surface of the mold member. Manufacturing method of injection molded products. A mold member having an inner surface that forms a cavity into which a thermoplastic resin is injected, which is used in manufacturing an injection-molded product in which an insert material is embedded inside a coating resin made of a thermoplastic resin, and a mold member in the cavity. A mold device provided with an insert material support mechanism for supporting the insert material.
The insert material support mechanism is
A main body having a first tip surface, which is a surface forming the cavity,
It has a support pin that is inserted into a pin support hole that opens at the first tip surface of the main body and supports the insert material at the second tip surface.
The main body and the support pin can move independently from each other in the mold opening / closing direction between the forward position and the backward position based on the drive action of the drive body .
The drive body is a spring that urges the main body and the support pin in the forward direction, respectively, and the load of the spring that urges the support pin is set to be smaller than the pressure of the thermoplastic resin, and the main body is set. The load of the spring that urges the portion is set to be smaller than the load of the spring that urges the support pin.
When both the main body and the support pin are in the forward position, the second tip surface is in a state of protruding from the first tip surface.
A mold device for molding an injection-molded product, characterized in that the second tip surface belongs to the same plane as the first tip surface when both the main body portion and the support pin are in the retracted position. The mold device for molding an injection-molded article according to claim 6 , wherein the spring for urging the support pin in the forward direction is housed inside the main body portion. 6 . The mold device for molding the injection-molded product described.

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