JP7063730B2 - Manufacturing method of resin molded products, welding jigs and resin molded products - Google Patents

Description

The present invention relates to a method for manufacturing a resin molded product, a welding jig, and a resin molded product.

Conventionally, a resin molded product by a gas injection molding method has been used for a vehicle door handle. By using the gas injection molding method, it is possible to obtain a molded product that is lighter in weight and has an appearance with less sink marks as compared with a normal injection molding method.

For example, Patent Document 1 discloses a method for manufacturing a hollow resin molded product. In this manufacturing method, first, a hollow molded product in which an overhanging portion for sealing the injection hole is arranged on the peripheral edge of the gas injection hole is formed. Then, the overhanging portion is crimped under heating to seal the gas injection hole.

Further, for example, Patent Document 2 discloses a method of arranging a sealing member in a gas injection hole and welding the sealing member to seal the gas injection hole.

Japanese Unexamined Patent Publication No. 8-142100 Japanese Unexamined Patent Publication No. 4-220318

However, according to the method disclosed in Patent Document 1, although the overhanging portion is melted to close the hollow portion, the quality of welding may not be stable and the sealing may be incomplete.

Further, according to the method disclosed in Patent Document 2, another component for sealing the injection hole is required, which may lead to an increase in cost.

The present invention has been made in view of such circumstances, and an object thereof is a method for manufacturing a resin molded product capable of airtightly sealing a gas injection hole while suppressing an increase in cost, and a welding jig. And to provide resin molded products.

In order to solve such a problem, the first invention comprises a first step of injecting a resin into a cavity of a mold and injecting gas into the cavity to form a resin molded product having a hollow portion. Provided is a method for manufacturing a resin molded product, which comprises a second step of sealing a gas injection hole in the resin molded product. Here, the resin molded product has a hollow cylindrical boss portion that is provided corresponding to the injection hole and communicates with the hollow portion. The second step is a welding step in which the welding means is brought into contact with the tip of the boss portion to weld the boss portion, and a rotation in which the resin molded product is rotated relative to the welding means around the boss portion. The welding means has a step, and the contact surface with the tip of the boss portion is formed in an uneven shape.

Here, in the first invention, in the rotation step, the table is centered on a reference axis passing through the welding means in a state where the resin molded product is placed on the rotatable table arranged opposite to the welding means. It is preferable that the process is to rotate the resin.

Further, in the first invention, the welding means is preferably an ultrasonic horn to which ultrasonic vibration is transmitted.

Further, in the first invention, the contact surface preferably has a concave shape with a recessed center.

Further, in the first invention, it is preferable that the contact surface includes a plurality of protrusions discretely arranged on the contact surface, or includes cross-shaped protrusions that intersect each other.

The second invention also provides a welding jig for sealing a gas injection hole in a resin molded product molded by a gas injection molding method. This welding fitting has a table on which a resin molded product is placed, a welding means that is arranged facing the table and can advance and retreat toward the table, and a means for welding the table around a reference axis passing through the welding means. It has a rotation mechanism that rotates relative to the relative. In this case, the table is provided with a holding portion in which the hollow tubular boss portion provided corresponding to the injection hole in the resin molded product holds the resin molded product in a posture corresponding to the rotation center of the table, and the welding means is By advancing toward the table, it comes into contact with the tip of the boss and welds the boss. The contact surface of the boss portion with the tip portion of the welding means is formed in an uneven shape.

Further, in the third invention, a main body portion having a hollow portion inside, a hollow cylindrical boss portion provided corresponding to a through hole penetrating the inside and outside of the main body portion, and a hollow cylindrical boss portion communicating with the hollow portion, and resin molding having the same. Provide goods. In this case, the boss portion includes a closing portion that closes the tip side of the boss portion, and the closing portion has a spiral shape.

According to the present invention, the gas injection hole can be hermetically sealed while suppressing the cost increase.

A perspective view showing the outside handle according to the present embodiment from the front side. A perspective view showing the outside handle according to the present embodiment from the back surface side. Enlarged perspective view of the main part of the outside handle shown in FIG. Sectional drawing along line segment AA shown in FIG. Explanatory drawing showing the manufacturing method of the outside handle Explanatory drawing showing the outside handle after the molding process Explanatory drawing schematically showing the structure of the welding jig Explanatory drawing showing the structure of the ultrasonic horn Explanatory drawing showing the details of the sealing process

Hereinafter, the resin molded product according to the present embodiment will be described by exemplifying the outside handle 1 for a vehicle. FIG. 1 is a perspective view showing the outside handle 1 according to the present embodiment from the front side. FIG. 2 is a perspective view showing the outside handle 1 according to the present embodiment from the back surface side. FIG. 3 is an enlarged perspective view showing a main part of the outside handle 1 shown in FIG. 2. FIG. 4 is a cross-sectional view taken along the line segment AA shown in FIG.

The outside handle 1 is a door handle fixed to the outside of a door outer panel constituting a vehicle door (not shown). The outside handle 1 is assembled to the side door in a posture in which the longitudinal direction of the handle is horizontal by using a handle mounting component (not shown). The outside handle 1 is mainly composed of a main body portion 10 and a boss portion 20.

From the viewpoint of weight reduction, the outside handle 1 is a resin molded product having a hollow inside, and is manufactured by a gas injection molding method. Further, the outside handle 1 is finished with a metallic appearance by plating the main outer surface including the design surface.

The main body portion 10 forms the main structure of the outside handle 1, and includes a handle portion 11, a hinge piece 12, and an operation protrusion portion 13.

The handle portion 11 has an elongated shape, and a grip portion 11a, which is a portion to be gripped by hand when the outside handle 1 is used, is formed in the central portion thereof.

The hinge piece 12 is provided on the back surface side of the handle portion 11 at one end in the longitudinal direction thereof. The hinge piece 12 is positioned on the front side of the vehicle when the outside handle 1 is assembled to the side door. The outside handle 1 is assembled to the side door by pivotally supporting the hinge piece 12. As a result, the handle portion 11 becomes rotatable in the horizontal direction around the hinge piece 12.

The operation protrusion 13 is provided on the back surface side of the handle portion 11 at the other end portion in the longitudinal direction thereof. The operation protrusion 13 is positioned on the rear side of the vehicle when the outside handle 1 is assembled to the side door. When the handle portion 11 is rotated so as to pull out the other end side of the handle portion 11 to the outside of the side door, the operation protrusion portion 13 moves with the rotation of the handle portion 11. The displacement of the operation protrusion 13 is transmitted to the door lock device (not shown) by a transmission means such as a cable. As a result, the locked state of the door lock device with respect to the vehicle body is released, and the side door can be opened.

In the main body portion 10 having such a configuration, the main portion thereof, specifically, the portion corresponding to the handle portion 11 is formed with a hollow (hollow portion 10a) inside. Further, at a required position of the main body portion 10, an injection hole 14 which is a through hole penetrating the inside and outside of the main body portion 10 is provided. The injection hole 14 is formed by injecting gas when molding the main body portion 10 by the gas injection molding method. In consideration of the product appearance and operability, the injection hole 14 is set in a region excluding the design surface of the outside handle 1 and the grip portion 11a. In the present embodiment, the injection hole 14 is provided on the back surface side of the handle portion 11 in the vicinity of the hinge piece 12.

The boss portion 20 is a hollow cylindrical member that stands up on the outer surface of the main body portion 10. In the present embodiment, the boss portion 20 has, for example, a cylindrical shape. The boss portion 20 is provided at a position corresponding to the injection hole 14, and the hollow portion thereof communicates with the hollow portion 10a of the main body portion 10 via the injection hole 14.

The boss portion 20 includes a closing portion 21 that closes the tip side of the boss portion 20. The closed portion 21 is formed by welding the tip portion of the boss portion 20. The closed portion 21 has a spiral shape that swirls around the central portion of the boss portion 20. The closing portion 21 seals the injection hole 14 with good airtightness. Therefore, with the plating treatment of the outside handle 1, after the plating solution enters the hollow portion 10a from the injection hole 14 or the outside handle 1 is assembled to the side door, liquid water such as rainwater enters from the injection hole 14. It is possible to prevent the hollow portion 10a from entering the hollow portion 10a.

Next, a method of manufacturing the outside handle 1 will be described. As shown in FIG. 5, the method for manufacturing the outside handle 1 includes a molding step (S1) and a sealing step (S2).

The molding step is a step of molding a resin molded product corresponding to the outside handle 1 by using a molding die (not shown) by a gas injection molding method. The molding die is a die used for molding a molded product by an injection molding method, and is mainly composed of a cavity mold and a core mold. The cavity mold and the core mold are molded to form a cavity, which is a molding space, between them.

In this molding step, first, the cavity mold and the core mold are molded, and then the molten resin is injected into the cavity through the resin passage (filling step). Next, a high-pressure gas is injected into the injected resin through a nozzle, and the injected gas is held at a predetermined pressure (gas injection step). The resin in the cavity is expanded by the gas to form a thin wall along the inner wall surface of the cavity, and the inside thereof is formed hollow. When the resin is cooled and solidified, the cavity mold and the core mold are opened, and the solidified resin molded product is taken out from the molding mold. Although the gas injection step is performed after the filling step, the filling step and the gas injection step may be performed at the same time.

FIG. 6 is an explanatory view showing the outside handle 1 after the molding process. In the figure, (a) is an enlarged perspective view showing a main part of the outside handle 1, and (b) is a cross-sectional view taken along the line segment BB of (a). Through a series of molding steps, it is possible to obtain an outside handle 1 having a main body portion 10 having a hollow portion 10a and a boss portion 20. In this case, the gas injection hole 14 is opened in the main body 10 corresponding to the position of the nozzle into which the gas is injected. At the same time, the boss portion 20 is formed so as to stand up on the peripheral edge of the injection hole 14. The boss portion 20 after the molding step has a height required for performing the sealing step described later. Further, the entire boss portion 20 is formed in a hollow shape. That is, the tip portion of the boss portion 20 is in an open state.

The sealing step is a step of sealing the injection hole 14 in the outside handle 1. This sealing step is performed using the welding jig 30. Here, FIG. 7 is an explanatory diagram schematically showing the configuration of the welding jig 30. Further, FIG. 8 is an explanatory diagram showing the structure of the ultrasonic horn 32.

The welding jig 30 is mainly composed of a table 31, an ultrasonic horn 32, and a welding table 33.

The table 31 is formed in a disk shape, and the outside handle 1 is placed on the table 31. The ultrasonic horn 32 is arranged to face the table 31 and is configured to be able to move forward and backward toward the table 31 by a drive mechanism (not shown). An ultrasonic vibration generator is connected to the ultrasonic horn 32, and by driving the ultrasonic vibration generator, ultrasonic vibration is transmitted to the ultrasonic horn 32. The ultrasonic horn 32 welds the boss portion 20 by ultrasonically vibrating in a state of being in contact with the tip portion of the boss portion 20 of the outside handle 1 (welding means). The welding table 33 is a rotation mechanism that rotates the table 31 with respect to the ultrasonic horn 32. The table 31 held on the welding table 33 passes through the ultrasonic horn 32 and rotates about a reference axis C along the advancing / retreating direction of the ultrasonic horn.

As one of the features of the present embodiment, the table 31 includes a holding portion 31a for holding the outside handle 1. By being held by the holding portion 31a, the outside handle 1 is in a posture in which the boss portion 20 coincides with the rotation center (reference axis C) of the table 31.

Further, as shown in FIG. 8A, the tip surface of the ultrasonic horn 32, that is, the contact surface 32a with the tip portion of the boss portion 20, has a concave shape with a recessed center. The contact surface 32a is discretely provided with a plurality of protrusions 32a1 each bulging to the outside of the contact surface 32a, and the surface of the concave surface is formed in an uneven shape. Due to this uneven shape, the surface area of the contact surface 32a is increased, and the contact surface 32a is caught by the resin, so that the flow of the resin by the contact surface 32a can be promoted.

The concave-convex shape of the contact surface 32a is not limited to the plurality of protrusions 32a1, and may be a plurality of holes each recessed inside the contact surface 32a. Further, as shown in FIG. 8B, the uneven shape of the contact surface 32a may be composed of cross-shaped ridges 32a2 that intersect each other. Further, the uneven shape of the contact surface 32a may be formed by a slit or the like.

FIG. 9 is an explanatory diagram showing details of the sealing process. Hereinafter, the details of the sealing process using the welding jig 30 will be described.

First, the outside handle 1 obtained in the molding step is set in the holding portion 31a of the table 31 (setting step (FIG. 9A)). The outside handle 1 is set with respect to the holding portion 31a so that the back surface side of the main body portion 10 provided with the boss portion 20 faces upward. The set outside handle 1 is held by the holding portion 31a so that the boss portion 20 is in a posture that coincides with the rotation center (reference axis C) of the table 31.

Next, the ultrasonic horn 32 is advanced toward the table 31, the contact surface 32a of the ultrasonic horn 32 is brought into contact with the tip of the boss portion 20, and the boss portion 20 is welded (welding step (FIG. FIG.)). 9 (b))). Specifically, the ultrasonic vibration generator is driven, and the ultrasonic horn 32 vibrates ultrasonically in contact with the boss portion 20. Even after the contact surface 32a of the ultrasonic horn 32 hits the tip of the boss portion 20, the ultrasonic horn 32 continues to be pushed out to the boss portion 20 with a constant force. The vibration of the ultrasonic horn 32 causes the boss portion 20 to melt from its tip side. At this time, due to the pushing force of the ultrasonic horn 32 and the concave shape of the contact surface 32a, the molten resin flows toward the center of the boss portion 20. The hollow region of the boss portion 20 is closed by the fluidized resin.

When the ultrasonic horn 32 is in contact with the ultrasonic horn 32 for a certain period of time, the driving of the ultrasonic vibration generator is stopped and the advance of the ultrasonic horn 32 is stopped. The ultrasonic horn 32 is maintained in close contact with the molten resin on the tip side of the boss portion 20. Then, the table 31 is rotated while the ultrasonic horn 32 is in close contact with the resin. As a result, the outside handle 1 placed on the table 31 rotates relative to the ultrasonic horn 32 about the boss portion 20 (rotation step (FIG. 9 (c))). The rotation of the table 31 is stopped on condition that a predetermined rotation amount or rotation time is reached.

After stopping the rotation of the table 31, the state is continued for a certain period of time. As a result, the molten resin on the tip side of the boss portion 20 is cooled and solidified (cooling step (FIG. 9 (d))).

Finally, the ultrasonic horn 32 is retracted from the table 31 and the ultrasonic horn 32 is separated from the boss portion 20 (evacuation step (FIG. 9 (e))).

By a series of sealing steps, the tip side of the boss portion 20 is welded, and the closing portion 21 that closes the tip side is formed. The closed portion 21 has a spiral shape that swirls around the central portion of the boss portion 20 due to the rotation of the table 31 (see FIG. 3). The closing portion 21 seals the injection hole 14 with good airtightness.

As described above, in the present embodiment, in the method for manufacturing the outside handle 1, the resin is injected into the cavity of the molding die, the gas is injected into the cavity, and the outside handle is provided with the hollow portion 10a inside. It has a molding step (first step) for molding 1 and a sealing step (second step) for sealing the gas injection hole 14 in the outside handle 1. The outside handle 1 has a hollow cylindrical boss portion 20 that is provided corresponding to the injection hole 14 and communicates with the hollow portion 10a. In this case, the sealing step is a welding step in which the welding means is brought into contact with the tip of the boss portion 20 to weld the boss portion 20, and the outside handle 1 is relative to the welding means centering on the boss portion 20. It has a rotation process of rotating the surface. In the welding means, the contact surface 32a with the tip of the boss portion 20 is formed in an uneven shape.

According to this manufacturing method, by carrying out the rotation step, the molten resin is dragged by the welding means and forced to flow. In the situation where the resin is simply welded by the ultrasonic horn 32, the resins are directed toward the center due to the contact force of the ultrasonic horn 32, and these are only bonded and welded. Then, the resin dragged by the welding means also flows in the circumferential direction, and the molten resins are intricately entangled with each other. As a result, welding is performed in a state where the resins are intertwined in multiple directions, so that the boss portion 20 can be reliably closed without creating a gap. As a result, the injection hole 14 can be hermetically sealed. Further, according to this method, it is not necessary to perform sealing by using a separate component, so that it is possible to suppress an increase in cost.

Further, in the present embodiment, in the rotation step, the reference axis C passing through the welding means with the outside handle 1 placed on the rotatable table 31 arranged to face the welding means. It is a process of rotating around.

According to this method, the rotation step can be performed by a simple mechanism of rotating the table 31. However, in the rotation process, the outside handle 1 may be rotated relative to the ultrasonic horn 32 around the boss portion 20, and the ultrasonic horn 32 is rotated while the table 31 is fixed. There may be. Further, the table 31 and the ultrasonic horn 32 may be rotated in opposite directions.

Further, in the present embodiment, the welding means is an ultrasonic horn 32 to which ultrasonic vibration is transmitted.

According to this method, the boss portion 20 can be effectively welded by melting the resin with the ultrasonic horn 32. In this embodiment, the ultrasonic horn 32 is exemplified as the welding means, but various welding methods such as heat welding can be widely used.

Further, in the present embodiment, the contact surface 32a has a concave shape with a recessed center.

According to this method, by pressing the ultrasonic horn 32 against the tip of the boss portion 20, the molten resin efficiently flows to the center side of the boss portion 20 following the concave shape of the contact surface 32a. do. As a result, the hollow region of the boss portion 20 can be effectively closed.

Further, in the present embodiment, the contact surface 32a includes a plurality of protrusions 32a1 discretely arranged on the contact surface 32a.

According to this method, the surface area of the contact surface 32a is expanded, and the plurality of protrusions 32a1 are entangled with the molten resin, so that the molten resin can be effectively moved. As a result, the molten resin also flows in the circumferential direction, and the molten resins are intricately entangled with each other. As a result, welding is performed in a state where the resins are intertwined in multiple directions, so that the boss portion 20 can be reliably closed without creating a gap.

Further, in the present embodiment, the welding jig 30 seals the gas injection hole 14 in the resin molded product molded by the gas injection molding method. The welding jig 30 has a table 31 on which the outside handle 1 is placed, a welding means that is arranged facing the table 31 and can advance and retreat toward the table 31, and a reference axis C that passes through the welding means. It has a welding table 33 (rotating mechanism) that rotates the table 31 relative to the welding means at the center. In this case, the table 31 is a holding portion in which the hollow cylindrical boss portion 20 provided in the outside handle 1 corresponding to the injection hole 14 holds the outside handle 1 in a posture corresponding to the rotation center of the table 31. It is equipped with 31a. The welding means advances toward the table 31 to abut on the tip of the boss portion 20 and welds the boss portion 20. The contact surface 32a with the tip of the boss portion 20 in the welding means is formed in an uneven shape.

According to this configuration, by setting the outside handle 1 on the table 31 and rotating the table 31, the molten resin is dragged by the welding means and forced to flow. In the situation where the ultrasonic horn 32 is simply in contact with each other, the resins are directed toward the center due to the contact force of the ultrasonic horn 32, and these are only bonded to perform welding. Then, the resin dragged by the welding means also flows in the circumferential direction, and the molten resins are intricately entangled with each other. As a result, welding is performed in a state where the resins are intertwined in multiple directions, so that the boss portion 20 can be reliably closed without creating a gap. As a result, the injection hole 14 can be hermetically sealed. Further, according to this method, it is not necessary to perform sealing by using a separate component, so that it is possible to suppress an increase in cost.

The welding jig 30 may be provided with a rotation mechanism for rotating the table 31 relative to the welding means, and has a configuration for rotating the welding means in addition to rotating the table 31 itself. May be good.

Although the method for manufacturing the outside handle and the welding jig according to the present embodiment have been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. Needless to say. Further, in the above-described embodiment, the outside handle has been illustrated as an example, but resin molded products other than the outside handle can also be widely applied.

Further, the resin molded product manufactured by the manufacturing method of the present invention itself also functions as a part of the present invention. In this case, the resin molded product has a main body portion having a hollow portion inside, and a hollow tubular boss portion provided corresponding to an injection hole penetrating the inside and outside of the main body portion and communicating with the hollow portion. The boss portion includes a closing portion that closes the tip side of the boss portion, and the closing portion is formed in a spiral shape.

Further, in the present embodiment, the welding step and the rotation step are carried out separately, but the rotation step may be carried out during the welding step.

1 Outside handle 10 Main body 10a Hollow part 11 Handle part 11a Grip part 12 Hinge piece 13 Operation protrusion 14 Injection hole 20 Boss part 21 Closure part 30 Welding jig 31 Table 31a Holding part 32 Ultrasonic horn 32a Contact surface 32a1 Protrusion 32a2 Protrusion 33 Welding table C Reference shaft

Claims (7)

The first step of injecting resin into the cavity of the mold and injecting gas into the cavity to form a resin molded product having a hollow portion.
It has a second step of sealing the gas injection hole in the resin molded product.
The resin molded product has a hollow cylindrical boss portion that is provided corresponding to the injection hole and communicates with the hollow portion.
The second step is
A welding step in which the welding means is brought into contact with the tip of the boss portion to weld the boss portion.
It has a rotation step of rotating the resin molded product relative to the welding means about the boss portion.
The welding means is a method for manufacturing a resin molded product in which a contact surface with a protruding end portion of the boss portion is formed in an uneven shape. The rotation step is
Claim 1 is a step of rotating the table around a reference axis passing through the welding means in a state where the resin molded product is placed on a rotatable table arranged opposite to the welding means. The method for manufacturing a resin molded product according to the description. The method for manufacturing a resin molded product according to claim 1 or 2, wherein the welding means is an ultrasonic horn to which ultrasonic vibration is transmitted. The method for manufacturing a resin molded product according to any one of claims 1 to 3, wherein the contact surface has a concave shape with a recessed center. The production of the resin molded product according to any one of claims 1 to 4, wherein the contact surface includes a plurality of protrusions discretely arranged on the contact surface, or cross-shaped protrusions intersecting each other. Method. In a plastic welding jig that seals a gas injection hole in a resin molded product molded by the gas injection molding method.
The table on which the resin molded product is placed and
A welding means arranged facing the table and capable of advancing and retreating toward the table.
It has a rotation mechanism for rotating the table relative to the welding means about a reference axis passing through the welding means.
The table includes a holding portion in which the hollow tubular boss portion provided corresponding to the injection hole in the resin molded product holds the resin molded product in a posture corresponding to the rotation center of the table.
The welding means abuts on the tip of the boss portion by advancing toward the table, and welds the boss portion.
A welding jig in which the contact surface of the boss portion with the tip portion of the welding means is formed in an uneven shape. The main body with a hollow part inside,
It has a hollow cylindrical boss portion that is provided corresponding to a through hole that penetrates the inside and outside of the main body portion and communicates with the hollow portion.
The boss portion includes a closing portion that closes the tip side of the boss portion.
The closed portion is a resin molded product having a spiral shape.

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