Production method for a resin molding

A production method for a resin molding (1) inserted a 1st plate (10) having many through holes (10a) and a 2nd plate (11) having many through holes (11a), which are arranged in parallel and facing each other during a manufacturing process, comprising a 1st plate process and a 2nd plate process. The 1st plate process in which, the 1st plate (10) moves to the 2nd plate (11) side from a 1st plate start position (U0) and returns a 1st plate end position (P3) near the 1st plate start position (U0) in a cavity filled with a molten resin (4) kept to a high pressure. The 2nd plate process in which, the 2nd plate (11) moves to the 1st plate (10) side from a 2nd plate start position (V0) and returns a 2nd plate end position (P4) near the 2nd plate start position in the cavity. This makes it possible to spread the molten resin (4) to even a shielded area with a reciprocal plate motion. That is, the molten resin (4) is able to pass through holes (10a, 11a) back and forth with the reciprocal plate motion and reach the shielded area finally. Therefore, the molten resin (4) spread through the surface of the 1st plate (10) and the 2nd plate (11), and a resin wettability of these plates are improved. And as a result, the resin molding (1) strength against a distortion is improved.

BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates to a production method for a resin molding inserted a 1st plate having many through holes and a 2nd plate having many through holes for reinforcing.

Description of Related Art

Generally, in the case of production for a resin molding, an insert material needs to be kept in a fixed position in a cavity to avoid a surface sink or a holding parts trace.

Concerning keeping an insert material in a cavity, a production method for a resin molding is disclosed, in which a fixing pin holds an insert material in a cavity, and a molten resin is injected into the cavity with keeping the insert material position (referred hereinafter to Japanese laid-open patent application No. h08-25410 as a 1st prior art).

In the case of an obstacle is in a cavity, a molten resin flow from is split and merged by the obstacle, and a sprit flow and a merge flow make a weld line, a V-shaped notch line etc. to a surface. And a production method for a resin molding to counter these problems is disclosed in which, a gate position and a cavity position are adjusted by a plunger or a screw position, and a weld line position is able to be controlled (referred hereinafter to Japanese laid-open patent application No. 2016-215406 as a 2nd prior art). And another countermeasure technique is disclosed too in which, a molten resin flow is controlled by regulating parts, and a weld line occurrence is able to be controlled (referred hereinafter to Japanese laid-open patent application No. 2010-274439 as a 3rd prior art).

And another production method for a resin molding is disclosed, in which, a resin molding inserted an insert material is formed as a semi-finished product, then next molten resin injection is carried out to the semi-finished product to make a final product (referred hereinafter to Japanese laid-open patent application No. h09-19940 as a 4th prior art).

And a metal mold which forms a cavity and supports an insert material is disclosed, in which the metal mold has a slidable part which is able to support the insert material. And this slidable part can be driven by a molten resin sub flow to a back end (referred hereinafter to Japanese laid-open patent application No. 2008-49592 as a 5th prior art).

From 1st to 5th prior art, an insert material is able to be kept in fixed position in a cavity with avoiding a surface sink or a holding parts trace. But in those prior art, total apparatus scale for a resin molding is too large, and a production process is too many and complicated.

A resin panel with inserted plates which are set at front and back, is enforced against a distortion, because of an increase of surface tensile strength by these insert plates. Additionally in the case that a molten resin wrap around these insert plates and these insert plates are integrated with concreted resin, a surface tensile strength become stronger.

And another resin panel with an inserted net is disclosed too (referred hereinafter to Japanese patent No. 6059841 as a 6th prior art).

In these resin panels, at a shielded area formed by an inserted material to a molten resin flow, a molten resin cannot go around this back area, and the resin filling failure caused by a lack resin wrapping around leads to an insufficient strength of a final product.

The present invention has been made based on the above drawbacks, and the main object of this invention is to prevent a resin filling failure at a shielded area formed by an inserted material.

In the present invention, a production method for a resin molding inserted a 1st plate having many through holes and a 2nd plate having many through holes, which are arranged in parallel and facing each other during a manufacturing process, contains a 1st plate process and a 2nd plate process.

The 1st plate process is that the 1st plate moves to the 2nd plate side from a 1st plate start position and returns a 1st plate end position near the 1st plate start position in a cavity filled with a molten resin kept to a high pressure.

The 2nd plate process is that the 2nd plate moves to the 1st plate side from a 2nd plate start position and returns a 2nd plate end position near the 2nd plate start position in the cavity.

This makes it possible to spread a molten resin to even a shielded area with a reciprocal plate motion. That is, a molten resin is able to pass many through holes back and forth with the reciprocal plate motion and reach the shielded area finally.

Therefore, a molten resin spread through the surface of the 1st plate and the 2nd plate, and a resin wettability of these plates are improved. And as a result, to prevent a void forming between plate and resin, a resin molding strength against a distortion is improved.

In the present invention, the cavity is formed by an upper metal mold and a lower metal mold, and the upper metal mold and the lower metal mold have a movable bar which is driven by an actuator and is able to move forward and backward in the cavity respectively. And the movable bar has an electromagnet which is able to catch and release a metal plate. And at the 1st plate end position the electromagnet current is cut off and the movable bar releases the 1st plate. And at the 2nd plate end position the electromagnet current is cut off and the movable bar releases the 2nd plate.

This makes it possible to make the movable bar structure and motion simple. Therefore, total apparatus scale for a resin molding is able to be compact, and the number of production processes is able to be reduced.

In the present invention, the 1st plate and the 2nd plate are a punched metal plate. A punched metal plate is easily obtainable in this field, therefore final products cost are able to be reduced.

In the present invention, the molten resin is a thermosetting resin including an epoxy and a polyurethane resin. A thermosetting resin is a liquid monomer at first, therefore a thermosetting resin reaches to the shielded area relatively easily because of a rich fluidity.

In the present invention, a wire is attached to the 1st plate or the 2nd plate.

This makes it possible to omit a process attaching a wire to a resin molding.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the following description of the depicted embodiments, the same reference numerals are used for features of the same type.

ReferringFIGS. 1 through 9shown is a production method for a resin molding inserted a 1st plate having many through holes and a 2nd plate having many through holes, according to a 1st embodiment of the invention.

As shownFIG. 1, a resin molding1is inserted a 1st plate10having many through holes10aand a 2nd plate11having many through holes11a. And the resin molding1is formed by a resin molding apparatus2, which is shown inFIG. 2.

As shownFIG. 1, the resin molding apparatus2forms the resin molding1covered a resin material3A all surfaces,

For example, the 1st plate10and the 2nd plate11are a thin punched metal plate (for example, these thickness t are 0.05 mm-3.0 mm.) having the many through holes10aand11arespectively, which show hexagonal shape and are arranged in honeycomb.

The punched metal plate is a magnetic substance metal plate and has many through holes at high density. And the 1st plate10and the 2nd plate11need to be reinforcing and easily magnetized only. Therefore, the 1st plate10and the 2nd plate11are not necessarily to be the punched metal plate. For example, the 1st plate10and the 2nd plate11may be a net, an expanded metal, a fabric, or a resin, which is able to be easily magnetized.

As shownFIG. 2, the resin molding apparatus2has a metal mold3consisting of an upper metal mold3aand a lower metal mold3b. And the upper metal mold3aand the lower metal mold3bseparate a cavity by a cavity forming part4a. And the resin molding1outline is determined by the shape of the cavity forming part4a.

In the cavity, the 1st plate10and the 2nd plate11are arranged in parallel and facing each other. And a molten resin4is injected into the cavity, and the resin molding1inserted the 1st plate10and the 2nd plate is formed. And a upper plane and a lower plane of the cavity forming part4awhich are arranged in parallel and facing each other are called a 1st inner plane4cand a 2nd inner plane4dhereafter respectively.

The molten resin4includes a thermosetting resin and a thermoplastic resin. And the molten resin4is able to be selected from a polypropylene, a polystyrene, an epoxy, a polyurethane etc., including an engineering plastic. Therefore, the price of the resin molding1is able to be reduced to select the lower price material.

At the left side of the lower metal mold3bin the figure, an injection gate5is provided, and at the center of the lower metal mold3bin the figure, a push pin5A, which is able to push out the resin molding1, is set slidably. And at both sides of the push pin5A, a pair of a through hole6, which penetrates the bottom of the lower metal mold3b, is provided.

And to each through hole6, a movable bar7is provided slidably. The movable bar7is driven by an actuator8and is able to move forward and backward in the cavity respectively. A pair of a through hole6aand the movable bar7are provided to the upper metal mold3a, too.

Each movable bar7has an electromagnet15which is able to catch and release a metal plate. The electromagnet15is controlled an electromagnet current by a controller16a, depending the position of the 1st plate10and the 2nd plate11. And at the through hole6,6a, a conductive tube15ais inserted. Therefore, the electromagnet15and the controller16aare connected by the conductive tube15a. The actuator8has a piston17, a cylinder18, a driving device Ps having an oil tank Ts, for example.

Around the upper metal mold3a, the piston17is connected to the upper end of the movable bar7, and is always biased from a cavity center Px to the 1st inner plane4cby a compression coil spring19, for example.

The driving device Ps is controlled by a controller20.

As shownFIG. 3, before injecting the molten resin4as a molten resin flow4h, an electric current is sent to the electromagnet15, to set the 2nd plate11at a 2nd plate start position V0.

And the molten resin4is injected into the cavity. At last, the cavity is filled with the molten resin4kept to a high pressure.

In this condition, the 2nd plate11moves to the 1st plate10side, that is to the cavity center Px side, from the 2nd plate start position V0and returns a 2nd plate end position P4in the cavity.

As shownFIG. 4, the actuator8drives the movable bar7connected to the 2nd plate11by the electromagnet15into the cavity. Therefore, the 2nd plate11moves from the 2nd plate start position V0to a predetermined distance P1.

In this process, the molten resin flow4hpass through the through holes11a, showing down flow in the figure.

And as shownFIG. 5, the 2nd plate11returns to the 2nd plate end position P4.

In this process, the molten resin flow4hpass through the through holes11a, showing up flow in the figure.

And as shownFIG. 6, the 2nd plate11is stopped at the 2nd plate end position P4near the 2nd plate start position V0. A gap between the 2nd plate11and 2nd inner plane4dis defined P2.

As shownFIG. 7, at the 2nd plate end position P4, the electromagnet15current is cut off and the movable bar7returns to the 2nd plate start position V0by using the actuator8.

The 2nd plate11is left at the 2nd plate end position P4, because the electromagnet15current is cut off. And at the 2nd plate start position V0, an upper plane15cof the electromagnet15and the 2nd inner plane4dare arranged to be flush.

And the molten resin4is spread to the every corner and the cavity is filled with the resin material3A.

At the upper metal mold3a, the movable bar7is operated with the same action in the cavity filled with the molten resin4kept to a high pressure.

Therefore, the 1st plate10moves to the 2nd plate11side, that is to the cavity center Px side, from the 1st plate start position U0.

In this process, the molten resin flow4hpass through the through holes10a, as an up flow.

Then the 1st plate10returns to the 1st plate end position P3.

In this process, the molten resin flow4hpass through the through holes10a, as a down flow.

And at the 1st plate end position P3, the electromagnet15current is cut off and the movable bar7returns to the 1st plate start position U0by using the actuator8.

The 1st plate10is left at the 1st plate end position P3, because the electromagnet15current is cut off. And at the 1st plate start position U0, an upper plane15cof the electromagnet15and the 1st inner plane4care arranged to be flush.

And the molten resin is spread to the every corner and the cavity is filled with the resin material3A, as well as the lower metal mold3b.

As shownFIG. 8, after having finished the molding, the metal mold3is opened by an actuator automatically timer controlled.

Then the push pin5A is driven by an actuator, and the resin molding1is pushed away from the metal mold3.

As shownFIG. 9, in the case of that the metal mold3is opened and the 1st plate10and the 2nd plate11are set at the 1st plate start position U0and the 2nd plate start position V0, respectively, an electric current is sent to the electromagnet15by the controller16awhich is commanded by an ECU20. Thus, the electromagnet15catches the 1st plate10and the 2nd plate11, respectively.

Then the driving device Ps sends oil from the oil tank Ts to the cylinder18, to drive the piston17against the compression coil spring19force.

And the movable bar7is driven to the cavity center Px side, therefore the 1st plate10and the 2nd plate11is able to be moved to the cavity center Px side, respectively.

Now the position of the 1st plate10and the 2nd plate11are detected by a position sensor. After the 1st plate10and the 2nd plate11reach to a predetermined distance, the ECU20commands the driving device Ps to return the 1st plate10and the 2nd plate11.

Then the cylinder18returns oil to the oil tank Ts, to return the piston17by the compression coil spring19force, the movable bar7returns, and the 1st plate10and the 2nd plate11returns to the 1st plate end position P3and the 2nd plate end position P4respectively.

And at the 1st plate end position P3, the electromagnet15current is cut off and the movable bar7releases the 1st plate10and, at the 2nd plate end position P4the electromagnet15current is cut off and the movable bar7releases the 2nd plate11.

Moreover, the movable bar7returns to the 1st plate start position U0and the 2nd plate start position V0, with left the 1st plate10at the 1st plate end position P3and the 2nd plate11at the 2nd plate end position P4, respectively. Finally, the upper plane15cof the electromagnet15and the 1st inner plane4cor the 2nd inner plane4dare arranged to be flush, and the driving device Ps is stopped.

In the 1st embodiment, the 1st plate10(the 2nd plate11) moves to the cavity center Px side from the 1st plate start position U0(the 2nd plate start position V0) and returns to the near position of the 1st inner plane4c(the 2nd inner plane4d).

This makes it possible that the molten resin flow4his able to pass many through holes10a,11aback and forth with the reciprocal plate motion, as shownFIG. 4andFIG. 5.

Therefore, the molten resin flow4his able to reach to even a narrow gap Pw which is made by the 1st plate10(the 2nd plate11) and the 1st inner plane4c(the 2nd inner plane4d).

Therefore, the molten resin4spread through the surface of the 1st plate10(the 2nd plate11), and a resin wettability of these plates is improved.

And as a result, to prevent a void forming between metal plate and resin, resin molding, for example resin panel, strength against a distortion is improved.

Incidentally, in the case of using a thermosetting resin as the molten resin4, a surface of the 1st plate10(the 2nd plate11) is compressed equally, for the resin material3A curing shrinkage, therefore, the resin molding1strength is improved, to advance the adhesiveness between a plate and a resin material. And in the case of using the injection molding, the resin molding1strength is improved too, with the resin material3A thermal shrinkage.

ReferringFIG. 10andFIG. 11shown is a production method for a resin molding1inserted a 1st plate10having many through holes10aand a 2nd plate11having many through holes11a, according to a 2nd embodiment.

In the 2nd embodiment, a wire40is attached to the cavity side of the 1st plate10.

This makes it possible that the wire40is embedded the molten resin4(the resin material3A). Therefore, the attachment process of the wire40to the resin molding1is able to be omitted. And the wire40needs not to be coated, because the resin material3A is an insulator.

Modification Forms

The cavity may be not only filled with a molten resin kept to a high pressure, but also filled with a molten resin kept to a normal pressure.

The number of the movable bar7may be not only one pair, but also one, three, etc.

The through holes10aand11amay show not only hexagonal shape, but also circle, rectangle, pentagonal etc. shape. And through hole6,6amay select a proper shape depending on the through holes10aand11a,

The 1st plate10and the 2nd plate11may be adopted not only planar plate but also curved surface plate.

The density distribution of the through holes10aand11amay be not only homogeneous, but also inhomogeneous.