JP3908141B2 - Molding resin injection method and molding resin injection structure to resin molding die - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a molding resin injection method and a molding resin injection structure to a resin molding die.
[0002]
[Prior art]
FIG. 9 is a view showing a switch substrate 500 with a molded resin in which a substrate 510 is insert-molded in a case 540. FIG. 9 (a) is a plan view, and FIG. 9 (b) is a cross-sectional view taken along the line aa of FIG. The figure and the figure (c) are back views (for example, refer to patent documents 1). As shown in the figure, in the case 540, a concave storage portion 541 that exposes the switch pattern groups 513 and 517 of the substrate 510 and the common switch pattern 521 is provided, and is stored in the storage portion 541 at the center thereof. An opening 525 for pivotally supporting a shaft provided on the lower surface of the sliding type not shown is provided. Terminal connection patterns 523, 525, and 527 are drawn out from the switch pattern groups 513 and 517 and the common switch pattern 521 of the substrate 510, respectively, and a metal plate terminal 550 is brought into contact therewith and fixed in the case 540. ing.
[0003]
Further, a plurality of openings 529 penetrating the substrate 510 are provided in the switch pattern groups 513 and 517 of the substrate 510, and the inside is filled with a molding resin constituting the case 540, and the surface thereof is an exposed surface of the substrate 510. And the same plane.
[0004]
In order to manufacture the switch board 500 with the molded resin, as shown in FIG. 10, the board 510 provided with the opening 529 and the terminals 550 in contact with the terminal connection patterns 523, 525, 527 of the board 510 are provided. The pin gate provided in the first mold 600 is stored and clamped in the first and second molds 600, 650, and the surface provided with the switch pattern groups 513, 517, etc. is in close contact with the surface of the second mold 650. A high-temperature and high-pressure molten molding resin is press-fitted from 601 to fill the cavity molding c formed on the joint surfaces of the first and second molds 600 and 650, and after cooling and curing, the first and second gold When the molds 600 and 650 are removed, the switch board 500 with the molded resin is completed.
[0005]
However, the conventional method for manufacturing the switch substrate 500 with a molding resin using a mold has the following problems.
(1) Since the projection 603 for forming the opening 525 provided in the approximate center of the substrate 510 must be provided in the first mold 600, the position of the pin gate 601 cannot be positioned in the approximate center of the substrate 510. It is installed at a position shifted from the center (a point p shown in FIG. 9C is a connection position of the pin gate 601). For this reason, a part of the flow pressure when a high-pressure molten molding resin is pressed into the cavity c from the pin gate 601 and sprayed on the back surface of the substrate 510 is a direction in which the substrate 510 is displaced in the plane direction (the direction of arrow a in FIG. 10). As a result, the position of the substrate 510 in the mold may be shifted by a minute dimension (for example, 1/100 mm). Although this deviation is minute, if the switch board 500 with a molded resin is reduced in size, the deviation cannot be ignored.
[0006]
(2) Depending on the shape and size of the molded product, there is a case where there is no place to connect the pin gate 601 to the outer periphery of the cavity c.
[0007]
(3) Since the pressure of the melt-molded resin injected from the pin gate 601 is high, the surface of the second mold 650 facing the pin gate 601 has a minute but dent as it is repeatedly molded. Due to the dents, there is a risk that a protrusion that slightly rises in the exposed portion of the substrate 510 of the molded resin-equipped switch substrate 500 is formed.
[0008]
(4) In the case of this switch board 500 with molded resin, an opening 529 is provided through the switch pattern groups 513 and 517 of the board 510, and the opening 529 is filled with the molded resin as described above. Since the distance between the pin gate 601 and each opening 529 is different, the filling pressure of the melt molding resin filled in each opening 529 is greatly different. For this reason, the filling pressure of the melt molding resin becomes large for the opening 529 close to the pin gate 601, and when the melt molding resin is press-fitted into the cavity c as shown in FIG. Molding resin enters the space between the surface of the mold 650 and the surface of the substrate 510, whereby the width (pitch) of the exposed portion of the switch pattern group 513 (or 517) is narrowed and an accurate on / off waveform is obtained. There was a risk of being lost.
[0009]
[Patent Document 1]
JP 2000-355022 A [0010]
[Problems to be solved by the invention]
The present invention has been made in view of the above points, and its purpose is to allow the molding resin injection port to be installed at a desired position such as the center position of the cavity, even when the substrate is insert-molded into the cavity. Providing a molding resin injection method and a molding resin injection structure for a resin molding die that does not cause misalignment of the substrate and that does not cause dents on the mold surface due to the melt molding resin that is injection molded into the cavity. There is to do.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, the present invention includes an injection step of injecting a molten molding resin from a resin injection port provided in the first mold into a cavity formed on the joint surface of the first and second molds. In the method of injecting a molding resin into a resin molding die, the injection step includes a gap formed between a protruding pin protruding from the second mold into the cavity and the resin injection port into which the protruding pin is inserted. urges Ri implantation step der injecting a molten molding resin into the cavity through the resin injection port of the first die through, and the ejector pins prior to said injection step to a resin injection port side In this way, the protruding pin is inserted into the resin injection port and closed in advance, and the protruding pin is pressed by the pressure of the melt-molded resin supplied to the resin injection port during the injection step, so that the protruding pin and the resin injection And wherein the resulting said clearance for molten resin injected between the mouth.
[0012]
Further, the present invention cuts the molded resin cured in the gap portion by moving the protruding pin together with the molded resin cured in the resin injection port after the molten molded resin injected into the cavity is cured. And a cutting step to perform.
[0014]
Further, according to the present invention, a substrate is accommodated in the cavity so that one surface is in contact with the second mold surface, and the protrusion pin is inserted into an opening provided in the substrate so that the inside of the cavity is inserted. In addition, the substrate is positioned at the same time, and the melt-molded resin is radially injected into the cavity from the vicinity of the opening of the substrate.
[0015]
The present invention also provides a molding resin injection structure into a resin molding die for injecting a molten molding resin into a cavity formed on the joint surface of the first and second molds. A melt-molded resin supplied to the resin injection port, comprising: a resin injection port provided in one mold; and a protruding pin that is slidably provided in the second mold and whose tip is inserted into and removed from the resin injection port. Is configured to be injected into the cavity through a gap formed between the ejection pin and the resin injection port , and the ejection pin is urged toward the resin injection port by the urging means. The urging means closes the inlet and has a resilience that is pressed by the pressure of the molten molding resin supplied to the resin injection port to create a gap for the molten resin injection between the protruding pin and the resin injection port. It features that you are To.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1A and 1B are views showing a switch substrate 10 with a molded resin manufactured by using the present invention, in which FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along line AA of FIG. . As shown in the figure, the molded resin-equipped switch substrate 10 is formed by molding a molded resin case 50 on the outer periphery and bottom surface of the substrate 20.
[0018]
As shown in FIG. 2, the substrate 20 is formed on a circular insulating substrate 21 made of a flexible synthetic resin film (for example, polyethylene terephthalate film). The common switch pattern 27 is printed and formed with an opening 29 penetrating in the center, and an opening 31 penetrating in a fan shape is provided in each switch pattern group 23, 25 at predetermined intervals. Yes. The opening 31 is formed in a substantially ring shape with the opening 29 as the center. That is, the substrate 20 is provided with the opening 31 so that the switch pattern groups 23 and 25 are turned on and off. A hatched portion 33 shown in FIG. 2 is an insulating printing layer for preventing conduction even when the sliding booklet slides thereon. Further, a lead-out portion 35 is provided on the outer periphery of the substrate 20, and three lead-out patterns 37 respectively connected to the two sets of switch pattern groups 23 and 25 and the common switch pattern 27 are drawn out thereon.
[0019]
Returning to FIG. 1, the case 50 has a bottom surface 51 and an outer peripheral wall 53 so as to cover the bottom surface and the outer periphery of the substrate 20, and a storage portion 54 formed by the bottom surface 51 and the outer peripheral wall 53. The two sets of switch pattern groups 23 and 25 and the common switch pattern 27 are exposed at the bottom. An opening 55 having the same inner diameter is provided at a position corresponding to the opening 29 in the center, and each opening 31 of the switch substrate 10 is filled with a molding resin constituting the case 50, and the surface thereof is the substrate 20. It is comprised so that it may correspond to the surface (exposed surface). The lead-out portion 35 of the switch board 10 is drawn out from the case 50 to the outside.
[0020]
Next, a method of manufacturing the switch board 10 with the molded resin using one embodiment of the present invention will be described. FIG. 3 is a view showing a mold structure for manufacturing the switch substrate 10 with a molded resin. As shown in the figure, this mold structure includes first and second molds 300 and 310 for forming a cavity C for forming the switch substrate 10 with molding resin on the joint surface between the first and second molds. A fixed side mold plate 321, a movable side mold plate 323 that accommodates the two molds 300, 310 in a nested manner, a runner stripper plate 325 and a fixed side mounting plate 327 installed on the rear surface side of the fixed side mold plate 321, Two spacer blocks 329 and 331 installed on the rear side of the movable mold plate 323, a movable mounting plate 332, two ejector plates 333 and 335 installed in the spacer block 329, and ejector plates 333 and 335. The sleeve pin 337 is fixed to be movable up and down by means of, and the sleeve pin 337 penetrates the sleeve pin 337 so as to be movable up and down, and biasing means (eg If it is configured by including a projecting pin 345 which established the spring steel) 341.
[0021]
The first mold 300, the fixed side mold plate 321, the runner stripper plate 325, and the fixed side mounting plate 327 are provided with a melt molding resin injection path 360 through them, and the tip thereof is connected to the substantially center of the cavity C. A resin injection port (ring cut gate) 301 is formed. The resin injection port 301 is positioned at a portion to be the opening 55 at the center of the switch board 10 with molded resin shown in FIG. 1, and the inner diameter of the tip is formed to be almost the same as the inner diameter of the opening 55. Further, reference numeral 361 shown in FIG. 3 denotes a dharma pin for pulling out and removing the molding resin cured in the melt molding resin injection path 360 after molding from the fixed side mold plate 321.
[0022]
An upper end surface of the sleeve pin 337 is exposed in the cavity C, and abuts on a surface provided with the switch pattern groups 23 and 25 of the substrate 20 inserted into the cavity C.
[0023]
The protruding pin 345 has a rod shape, and the outer diameter thereof is the same as the inner diameter of the openings 29 and 55 in the center of the switch board 10 with molded resin shown in FIG. It is smaller than the part. As shown in FIG. 4 described below, the base portion of the tip portion 347 is a tapered surface 349 that expands in the outer diameter direction of the rod-shaped protruding pin 345, and the lower end side of the tapered surface 349 is a ring-shaped cut. Part 350 is configured. Returning to FIG. 3, the protrusion pin 345 enters the center of the cavity C and is pushed up to a predetermined position by the biasing means 341. In the pushed-up state, the tip (tip portion 347 and taper surface 349) is the resin injection. It enters the entrance 301. Accordingly, the lower portion of the cut portion 350 of the protruding pin 345 that has entered the resin injection port 301 blocks the resin injection port 301. On the other hand, a stopper portion 351 is provided at the lower portion of the protruding pin 345 by increasing its inner diameter, and the stopper pin 353 protrudes from the lower surface thereof. A biasing means mounting base 355 is fixed on the surface of the movable side mounting plate 332, and a biasing means 341 is fixed on the upper part thereof. The stopper pin 353 passes through the urging means mounting base 355 and the lower end thereof faces the surface of the movable side mounting plate 332 with a predetermined distance therebetween. A predetermined gap is also provided between the upper surface of the stopper portion 351 and the ejector plate 335.
[0024]
Next, a method for manufacturing the switch substrate 10 with a molded resin using the mold structure shown in FIG. 3 will be described. Here, FIG. 4 to FIG. 8 are enlarged cross-sectional views of the main part showing the state around the cavity C in the molding process. First, when a high-temperature and high-pressure melt-molded resin is press-fitted into the melt-molded resin injection passage 360 shown in FIG. 3, the melt-molded resin reaches the resin injection port 301, and the tip of the ejection pin 345 is moved to the arrow shown in FIG. It is pressed in the A1 direction and lowered against the elastic force of the biasing means 341. As a result, as shown in FIG. 5, the melt-molded resin is filled into the cavity C from the gap (ring-shaped gap) between the cut portion 350 of the protruding pin 345 and the resin injection port 301. At this time, the protrusion pin 345 is restricted from moving downward by the stopper pin 353 at the lower end thereof coming into contact with the surface of the movable mounting plate 332. Then, the melt-molded resin is cured in the state shown in FIG.
[0025]
Next, by pulling up the runner stripper plate 325 and the fixed-side mounting plate 327 shown in FIG. 3, the molding resin cured in the molten molding resin injection path 360 is simultaneously pulled up. At this time, the portion of the tip portion 347 of the ejection pin 345 shown in FIG. 5 is integrated with the molding resin cured and shrunk around it, so that it is pulled up and moved into the resin injection port 301 integrally with the molding resin, and the ejection pin The ring-shaped molding resin with a thin gap between the cut portion 350 of the 345 and the resin inlet 301 is cut as shown in FIG. Thus, the cutting means is constituted by the cut portion 350 of the protruding pin 345 and the resin injection port 301, and the molding resin is surely cut by this cutting means, so the resin injection port 301 of the molded resin (case 50) after molding. There is almost no trace associated with the cutting of the molded resin in the connected portion, and a clean surface can be obtained.
[0026]
Further, when the runner stripper plate 325 and the fixed side mounting plate 327 shown in FIG. Thus, as shown in FIG. 7, the fixing with the pulled molding resin is released, and only the molding resin is pulled up.
[0027]
Then, as shown in FIG. 8, the first and second molds 300 and 310 are separated from each other, and at this time, the ejector plates 333 and 335 shown in FIG. The switch board 10 with the molding resin, which has been molded by this, is pulled out from the second mold 310 and taken out.
[0028]
As in this embodiment, the melt-molded resin supplied to the resin injection port 301 of the first mold 300 is injected into the cavity C from the gap formed between the tip of the ejection pin 345 and the resin injection port 301. By doing so, the melt-molded resin flows out almost radially outward from the outer periphery of the resin injection port 301 of the cavity C. For this reason, the flow pressure of the melt-molded resin is substantially uniform from the substantially center (portion of the opening 29) toward the outside in the radial direction on the surface of the substrate 20 fixed by inserting the protruding pin 345 into the opening 29. Therefore, the position of the substrate 20 does not shift in the cavity C. In addition, since the melt-molded resin injected into the cavity C from the resin injection port 301 is not concentrated and sprayed on a part of any surface of the mold, it is possible that the mold will be depressed over time. Therefore, the molded product is not deformed by this dent. Further, since the distance from the outer periphery of the resin injection port 301 to each opening 31 of the substrate 20 is almost equal, the pressure and flow velocity of the melt-molded resin flowing into any opening 31 are the same, as shown in FIG. As shown, this problem can be easily adjusted so that the pressure and flow rate of the melt-molded resin are not so high that the molding resin wraps around from the opening 529 to the surface of the second mold 650 and the surface of the substrate 510. Dots can be easily prevented.
[0029]
Further, as in this embodiment, in the case of a molded product (case 50) having an opening 55 penetrating therein, a melt-molded resin can be filled into the cavity C from the inner peripheral side of the portion that becomes the opening 55. Therefore, it is possible to inject a molding resin even in a molded product having a shape, structure, and size where there is no place to connect the pin gate on the outer peripheral side.
[0030]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. Note that any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are exhibited. Structure and biasing means of the pin 345 out can collision For example, it is needless to say various modifications are possible such as the movement restricting means for stopping it during vertical movement.
[0031]
Further, in the above embodiment, the example in which the switch substrate 10 with the molding resin is manufactured by housing the substrate 20 in which the switch pattern is formed in the cavity C is shown, but the substrate in which the resistance pattern is formed is manufactured according to the present invention. For example, a substrate with a molding resin formed by insert molding of other various substrates may be used, and a member such as the substrate 20 may be formed by simply molding the molding resin without insert molding.
[0032]
【The invention's effect】
As described above in detail, according to the invention, the melt molding resin supplied to the resin injection port of the first mold is injected into the cavity from the gap formed between the tip of the ejection pin and the resin injection port. As a result, the melt-molded resin flows out from the outer periphery of the resin injection port almost radially outward in the cavity. For this reason, the molten molding resin injected into the cavity from the resin injection port is not sprayed in a concentrated manner on any part of the mold surface, and a part of the mold surface is recessed over time. There is no such thing and the molded product is not deformed by this dent.
[0033]
Also, if it is a molded product with an opening inside it, it can be filled with melt-molded resin from the inner circumference side of the part that becomes the opening, so there is no place to connect the pin gate on the outer circumference side of the cavity・ Even if it is a molded product of structure and dimensions, it can be easily molded.
[0034]
Also, when the substrate is stored in the cavity and the substrate is fixed by inserting a protruding pin into the opening provided in the stored substrate, the flow pressure of the molten molding resin is applied to the surface of the substrate. If the openings are provided substantially at the center of the substrate, the position of the substrate does not shift in the cavity.
[0035]
Further, according to the present invention, after the molten molding resin injected into the cavity is cured, the molded resin cured at the gap portion is cut by pulling the protruding pin into the resin injection port together with the molding resin cured within the resin injection port. Therefore, the cutting means is constituted by the protruding pin and the resin injection port. Therefore, the cutting resin can be surely cut by this cutting means, and the molded resin is almost cut at the portion where the resin injection port of the molded resin is connected after molding. No traces are left behind and the surface can be made clean.
Further, according to the present invention, since the urging means is provided on the protruding pin, the resin injection port can be reliably closed by the outer periphery of the protruding pin before the start of molding.
[Brief description of the drawings]
1A and 1B are views showing a switch board 10 with a molded resin configured according to the present invention, in which FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along the line AA in FIG. is there.
FIG. 2 is a plan view of a substrate 20;
FIG. 3 is a view showing an example of a mold structure for manufacturing a switch substrate 10 with a molded resin.
FIG. 4 is an enlarged cross-sectional view of a main part showing a state around a cavity C in a molding process.
FIG. 5 is an enlarged cross-sectional view of a main part showing a state around a cavity C in a molding process.
FIG. 6 is an enlarged cross-sectional view of a main part showing a state around a cavity C in a molding process.
FIG. 7 is an enlarged cross-sectional view of a main part showing a state around a cavity C in a molding process.
FIG. 8 is an enlarged cross-sectional view of a main part showing a state around a cavity C in a molding process.
9A and 9B are diagrams showing a switch board 500 with a molded resin in which a board 510 is insert-molded in a case 540, FIG. 9A being a plan view, and FIG. 9B being aa of FIG. 9A. Sectional drawing and FIG.9 (c) are back views.
FIG. 10 is a diagram showing a method for manufacturing a switch substrate 500 with a molded resin.
FIG. 11 is an explanatory diagram of a conventional problem.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Switch board | substrate 20 with molding resin Board | substrate 21 Insulating board | substrate 23, 25 Switch pattern group 27 Common switch pattern 29 Opening part 31 Opening 50 Case 51 Bottom face 53 Outer peripheral wall 54 Storage part 55 Opening part 300 1st metal mold 301 Resin injection port (ring Cut gate)
310 Second mold C Cavity 341 Biasing means 345 Extrusion pin 347 Tip portion 350 Cut portion 360 Melt molding resin injection path

Claims (4)

A method of injecting a molding resin into a resin molding die having an injection step of injecting a molten molding resin from a resin injection port provided in the first die into a cavity formed on a bonding surface of the first and second molds In
In the injection step, the resin is injected from the resin injection port of the first mold through a gap formed between the protrusion pin protruding into the cavity from the second mold and the resin injection port into which the protrusion pin is inserted. Ri implantation step der injecting a molten molding resin into the cavity,
And before the injection step, by urging the protrusion pin toward the resin injection port side, the protrusion pin is inserted into the resin injection port in advance and blocked,
A gap for injecting the molten resin is formed between the extrusion pin and the resin injection port when the extrusion pin is pressed by the pressure of the molten molding resin supplied to the resin injection port during the injection step. A method of injecting molding resin into a mold for resin molding.   A cutting step of cutting the molded resin cured in the gap portion by moving the extrusion pin into the resin injection port together with the molding resin cured in the resin injection port after the molten molding resin injected into the cavity is cured; The method for injecting a molding resin into a resin molding die according to claim 1.   The substrate is accommodated in the cavity so that one surface is in contact with the second mold surface, and the protruding pin is inserted into the opening provided in the substrate, thereby positioning the substrate in the cavity. 3. The method for injecting a molding resin into a resin molding die according to claim 1 or 2, wherein the molten molding resin is radially injected into the cavity from the vicinity of the opening of the substrate. In the molding resin injection structure to the resin molding die for injecting the molten molding resin into the cavity formed on the joint surface of the first and second molds,
The molded resin injection structure comprises a resin injection port provided in the first mold, and a protruding pin that is slidably provided in the second mold and whose tip is inserted into and removed from the resin injection port.
The melt-molded resin supplied to the resin injection port is configured to be injected into the cavity through a gap generated between the protruding pin and the resin injection port ,
And the protrusion pin closes the resin injection port by being urged toward the resin injection port by the urging means,
The biasing means has a resilience that is pressed by the pressure of the molten molding resin supplied to the resin injection port to generate a gap for molten resin injection between the protruding pin and the resin injection port. Molding resin injection structure of mold for resin molding.

Images