JPH1016014A - Injection molding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a block of a first block and a second clock which slides with the first block by forming a projecting part (a rib and a bolt boss part) of a molding, in the bottom force of a mold consisting of a core main body and the block, and move the second block in the counterporojecting part direction prior to the opening of the mold to prevent the projecting part from biting at the molding and thereby secure the smooth mold parting properties. SOLUTION: This projection molding device manufactures an injection molding 4 with a projecting part 2 using a bottoms force 6 consisting of a core main body 17 and blocks 14, 19 and a top force 5. The block is constituted of the first block 14 and the second block 19 which has a recessed part for molding the projecting part 2 and slides with the first clock 14. In addition, a moving means 21 is provided which moves the second block 19 to the counterprojecting part side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding method for forming an injection-molded article having a projecting portion such as a reinforcing rib or a bolt-up boss portion projecting from a bumper body such as a resin bumper for a vehicle. It relates to a molding device.

[0002]

2. Description of the Related Art In general, a synthetic resin bumper (plastic bumper) for a vehicle is provided with an opening for arranging a lamp such as a fog lamp or a combination lamp. Around the opening, a bumper main body is attached to a vehicle body. Boss (protruding portion) for bolt-up is integrally formed, and a reinforcing rib is formed integrally with a necessary portion of the bumper main body to increase its mechanical strength.

For example, as shown in FIG. 9, a bumper 81 as an injection-molded product is integrally formed with a bolt boss 82 and a rib 83 as a projecting portion, and the bumper 81 is formed by a claw member 85 of a robot hand 84 as a take-out means. 81 is a mold member 86 such as a core directly above the lower mold or a protruding block.
From the bolt boss 82 and the rib 83
Is caught in the mold member 86, so that the bumper 81 as a product cannot be released from the mold satisfactorily.
(See the imaginary line α in FIG. 9), and there is a problem that mold release failure such as breakage of the bolt boss portion 82 occurs. In the drawing, P indicates a parting line.

On the other hand, injection molding dies as described in Japanese Utility Model Application Laid-Open No. 62-144615 have already been invented. As shown in FIG. 10, the slide core 9 is provided on a mold mating surface of a fixed mold 91 and a movable mold 92, and slides at a predetermined angle with respect to the fixed mold 91 when the mold is opened.
3, a side eject pin 95 which is provided so as to be able to advance and retreat with respect to the slide core 93 and presses the molded product 94 in a direction for separating the molded product 94 from the slide core 93, and one end of which is slidable on the slide core 93. The first link arm 96 which is pivotally supported and cross-engaged with the side eject pin 95 so as to advance and retreat the side eject pin 95 by reciprocating swing, and one end of the first link arm 96 swingable by the above-mentioned fixed mold 91. A second link arm 97 pivotally supported and connected to form a substantially V-shape with the first link arm 96. After the movable mold 92 is separated, the ejector rod 98 is moved upward. When the slide core 9
3 slides obliquely upward along the slant surface 99, the connecting point between the first link arm 96 and the second link arm 97 is displaced in the direction of the arrow in FIG. 10, and the side eject pin 95 is moved leftward in the figure. Although the molded product 94 is moved to separate the molded product 94 from the left end surface of the slide core 93 in the drawing, it is not intended to prevent the protrusion 100 of the molded product 94 from biting into the slide core 93, so that the same separation as described above is performed. There was a problem that mold failure occurred.

[0005]

According to a first aspect of the present invention, there is provided a lower mold having a core body and a block, wherein the above-described block includes a first block and a protrusion (a rib or a bolt boss) of a molded product. Etc.) and a second block slidable with respect to the first block, and by moving the second block in the anti-projection direction before opening the mold, it is possible to prevent the projection from biting, It is an object of the present invention to provide an injection molding device capable of ensuring good releasability.

According to a second aspect of the present invention, in addition to the object of the first aspect, when the above-mentioned core body is separated from the first block, the above-mentioned second block is moved to the side opposite to the protruding portion. An object of the present invention is to provide an injection molding apparatus capable of removing a second block from a protruding portion of an injection molded product by effectively utilizing a mold opening space (separation space) by moving the mold.

According to a third aspect of the present invention, in addition to the object of the second aspect, the second block is urged in the direction opposite to the protruding portion so that the second block is closed when the mold is closed. When the mold is closed, a good projection molding recess can be formed by the pressing force of the core body by being pressed by the main body to form the projection forming recess, and when the mold is opened, It is an object of the present invention to provide an injection molding apparatus capable of automatically removing a second block from a projecting portion of a molded product by an urging force.

According to a fourth aspect of the present invention, in addition to the object of the second or third aspect, an ejector pin for projecting a molded product is provided so as to penetrate the second block. The ejector pin can also serve as the sliding guide of the second block, and, of course, a portion (a protruding portion of a molded product) that is easily bitten during ejection can be directly pushed by the ejector pin, thereby improving the releasability. It is an object of the present invention to provide an injection molding apparatus capable of performing the above.

According to a fifth aspect of the present invention, in addition to the object of the fourth aspect, by forming the ejector pin into a two-step projecting structure, a two-step molding of the molded product by the ejector pin is realized. It is an object of the present invention to provide an injection molding device that forms a gap between a first block and a molded product (product) when protruding to further improve mold releasability and perform reliable and good mold release. I do.

According to a sixth aspect of the present invention, there is provided an injection molding apparatus capable of surely releasing a molded article having an undercut portion by providing an inclined core for molding the undercut portion. Aim.

[0011]

The invention according to claim 1 of the present invention is an injection molding apparatus for forming an injection molded article having a projecting portion by a lower mold and an upper mold having a core body and a block. Wherein the block comprises a first block, and a second block having a recess forming the protruding portion and slidable with respect to the first block. It is an injection molding apparatus provided with a moving means for moving to an injection molding machine.

According to a second aspect of the present invention, in addition to the configuration of the first aspect of the present invention, the moving means moves the second block to the anti-projection portion when the core body is separated from the first block. It is an injection molding device that moves to the side.

According to a third aspect of the present invention, in addition to the configuration of the second aspect of the present invention, the second block is urged in the direction opposite to the protruding portion, and is pressed by the core body when the mold is closed. And an injection molding apparatus in which a projection forming recess is formed in cooperation with the first block.

According to a fourth aspect of the present invention, there is provided an injection molding apparatus in which an ejector pin for projecting a molded product is provided through the second block in addition to the configuration of the second or third aspect of the present invention. The device is characterized in that:

According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect, the lower end of the ejector pin is in contact with one end of a seesaw lever provided on an ejector plate, The injection molding apparatus is configured so that the ejector pin projects in two steps by the action of (1).

According to a sixth aspect of the present invention, there is provided an injection molding apparatus for forming an injection molded article having an undercut portion, wherein the inclined core for forming the undercut portion is provided,
The injection molding apparatus is provided with guide means for moving the inclined core in an oblique direction away from the undercut portion.

[0017]

According to the first aspect of the present invention, the lower mold having the core body, the first block and the second block, and the upper mold form an injection molded article having a projecting portion. In this case, the above-mentioned moving means (including both the electric moving means and the mechanical moving means) moves the above-mentioned second block to the side opposite to the protruding portion before the mold is opened after the resin injection. There is an effect that it is possible to prevent the part from being bitten by the mold and to ensure good releasability. For this reason, it is possible to reliably prevent a mold release failure such as a chuck error, a deformation of a molded product, or a breakage of a protruding portion, which is seen in conventional means.

According to the invention described in claim 2 of the present invention,
In addition to the effect of the first aspect of the present invention, the moving means moves the second block to the side opposite to the protruding portion when the core body is separated from the first block, so that the mold opening space (separated space). From the projecting part of the injection molded product
There is an effect that the block can be removed.

According to the third aspect of the present invention,
In addition to the effect of the second aspect of the present invention, the second block is urged in the direction opposite to the protruding portion and is pressed by the core body when the mold is closed to form the recess for forming the protruding portion. In some cases, a good protrusion forming recess is formed by the pressing force of the core body against the urging force, and when the mold is opened, the second block is automatically formed by the urging force in the direction opposite to the protrusion. There is an effect that it can be removed from the protrusion of the molded product. In short, it is possible to effectively use the operations of closing and opening the mold to form the concave portion and remove the second block from the projecting portion.

According to the invention described in claim 4 of the present invention,
In addition to the effect of the second or third aspect of the present invention, since the ejector pin for projecting the molded article penetrates the second block, the ejector pin can also serve as the sliding guide of the second block. In addition, it is possible to directly press a portion (a protruding portion of a molded product) which is likely to bite at the time of ejection with the ejector pin, thereby improving the releasability.

According to the invention described in claim 5 of the present invention,
In addition to the effect of the fourth aspect of the present invention, since the ejector pin has a two-stage projecting structure, the ejector pin projects between the first block and the molded product (product) when the molded product is projected in two stages. A gap can be formed. As a result, there is an effect that the releasability can be further improved, and a reliable and good release can be performed.

According to the invention described in claim 6 of the present invention,
In forming an injection molded product having an undercut portion, since an inclined core for forming the undercut portion was provided,
When the mold is released, the inclined core moves in the inclined direction and comes off the undercut portion. Therefore, there is an effect that the mold having the undercut portion can be reliably released.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. The drawings show an injection molding apparatus, and are shown in FIGS.
In this injection molding apparatus, a vehicle resin bumper 4 having a bolt boss 2 with a rib 1 as a projection and an undercut 3 is injection-molded with an upper mold 5 and a lower mold 6.

The lower die 6 has a holder 8 mounted on a holder plate 7 located at a lower portion, and an ejector plate 9 disposed above the holder plate 7 in parallel with the holder plate 7. This ejector plate 9
Is a plate that can be moved by an ejector rod 10 (see FIG. 4).
The protruding block 14 as a first block is integrally connected via a separate guide pin 13, and the protruding block 14 as a first block is integrally connected via another guide pin 13. Here, a concave portion 12a (see FIG. 7) is formed in a portion of the directly above core 12 corresponding to the undercut portion 3 of the bumper 4 for forming the same.

A large push as an inclined core for forming an undercut portion is provided between the guide pins 11 and 13 of the above-described ejector plate 9 through a guide pin 15 for a large push-up core which is slidably disposed in a laterally movable manner. A lifting core (hereinafter simply referred to as a lifting core) 16 is provided. Further, while a core body 17 is fixed on the upper portion of the holder 8, a space 18 is formed at a corner of the protruding block 14 facing the core body 17 as shown in FIG. 2.

The protruding block 14 is provided with a hole 14a corresponding to the bolt boss 2 of the bumper 4, and the hole 14a communicates with the space 18. Also, a nest 19 (so-called sleeve set block) as a second block which protrudes into the hole portion 14a and the space portion 18 and is slidable in the vertical direction with respect to the block 14.
The bolt boss portion 2 and the rib 1 of the bumper 4 are formed by the insert 19.

The above-mentioned insert 19 has a flange portion 19a at a substantially intermediate portion in the vertical direction, and stopper bolts 20, 20 penetrating through insertion holes 19b, 19b of the flange portion 19a.
20 is screwed and fixed to the block 14, and a second space is provided between the projecting block 14 and the upper surface of the flange portion 19a.
Coil springs 21 and 21 are stretched as an example of a moving means for moving the nest 19 as a block to the anti-projection side.

The above-described coil springs 21, 21 are used when the core body 17 is separated from the first block 14 (see FIG. 4).
In addition, the nest 19 as the second block is moved to the side opposite to the protruding portion. The above-mentioned insert 19 is always urged downward (the side opposite to the bolt boss 2 as a protruding portion) by the above-mentioned coil spring 21 and is pressed by the core body 17 when the mold shown in FIGS. 1 and 2 is closed. A projection-forming recess 19c is formed.

By the way, a two-stage projecting unit 22 is provided on the above-mentioned agent plate 9. The two-stage projecting unit 22 includes a seesaw lever 25 that can swing about a support shaft 24 above the plate 23 and a seesaw pin 26 provided at one end of the seesaw lever 25.
And an ejector core pin 27 as an ejector pin for projecting a molded product provided on the other end side of the above-mentioned seesaw lever 25, and a ball 28 is formed at the lower end of the ejector core pin 27 in contact with the seesaw lever 25. At the same time, the coil spring 29 provided using the concave portion 9a of the ejector plate 9 constantly urges the spring downward.

The ejector core pin 27 described above is
As shown in FIG. 3, the stepped portion 27a on the upper end side of the ejector core pin 27 is in contact with the lower end surface of the bolt boss portion 2 as shown in FIG. The lower surface of the holder 8 contacts the seesaw pin 26 at a predetermined stroke (ejector stroke) of the ejector rod 10 shown in FIG. When the pin 26 is pushed down and the seesaw lever 25 is displaced about the support shaft 24, the ejector core pin 27 is further protruded and protrudes between the block 14 and the bumper 4 as a molded product as shown in FIGS. Such a gap g
Are formed. That is, the state shown in FIG. 6 indicates the first-stage protruding state, and the state shown in FIG.
This shows the protruding state of the step. In the figure, 30
Is a guide pin for positioning the upper die 5, and 31 is a bush.

The illustrated embodiment is configured as described above, and the operation will be described below. Bumper 4 as an injection molded product
The upper mold 5 is closed with respect to the lower mold 6 when molding is performed.
When the mold is closed, the nest 19 as the second block is pressed by the core body 17 as shown in FIG. 1 against the urging force of the coil spring 21 to be in a state shown in the drawing, and a concave portion 19c for forming a protrusion is formed (see FIG. 2). Are formed.

The molten resin is injected into the cavity formed by the upper mold 5 and the lower mold 6 to form a bumper 4 having a rib 1, a bolt boss 2, and an undercut 3, and the upper mold 5 is molded. After releasing, to release this bumper 4,
First, as shown in FIG. 4, the ejector plate 9 as a movable element and the core 1 directly above
2. The push-up core 16 and the projecting block 14 are ejected by a predetermined amount to the holder 8 as a fixing element and the core body 17. Here, the above-described push-up core 16 moves diagonally upward along the direction in which the guide pin 15 is directed.

As shown in FIGS. 4 and 5, when the protruding block 14 as the first block is separated upward from the core body 17, a nest 19 slidably disposed on the protruding block 14 is a coil. The spring 21 is moved downward by the downward biasing force, and comes off the bolt boss 2 with the rib 1 of the bumper 4. In addition, the lower movement lower limit position of the above-mentioned nest 19 is regulated by a large-diameter stopper portion of the stopper bolt 20.

Next, when the ejector rod 10 is further moved upward from the state shown in FIGS. 4 and 5 as shown in FIG. 6, the ejector plate 9 as a movable element, the core 12 directly above,
The bumper 4 passes through the push-up core 16 and the protruding block 14.
Is further moved in the releasing direction, and the undercut portion 3 of the bumper 4 is disengaged from the push-up core 16 by the diagonally upward movement of the push-up core 16, while the lower surface of the holder 8 is projected in two steps and the seesaw pin in the unit 22. Abuts the upper end of 26.

When the ejector rod 10 is further moved upward from the state shown in FIG. 6 as shown in FIGS.
Relative to the ejector plate 9, the holder 8
The see-saw pin 26 is pressed down on the lower surface of the ejector core pin 27, and the ejector core pin 27 projects through the see-saw lever 25 to perform an operation. The gap g between the projecting block 14 and the bumper 4 as a molded product as shown in FIG. To form The bumper 4 released in this manner is gripped by the claw member of the robot hand and taken out of the lower die 6.

In short, the lower die 6 having the core body 17, the first block (see the protruding block 14) and the second block (see the insert 19), and the upper die 5 have a protruding portion (see the bolt boss portion 2). Injection molding (see bumper 4)
Is formed, the moving means (coil spring 2
1) moves the above-mentioned second block (see the insert 19) to the side opposite to the protruding portion when the mold is opened after the resin injection, so that the protruding portion (see the bolt boss portion 2) of the molded product (see the bumper 4).
Is prevented from being stuck in the mold, and good releasability can be ensured. For this reason, it is possible to reliably prevent mold release defects such as chuck errors, deformation of the molded product (see the bumper 4), and breakage of the protruding portion (see the bolt boss portion 2) as seen in the conventional means.

The above-mentioned moving means (see the coil spring 21) moves the above-mentioned second block (see the insert 19) to the side opposite to the protruding portion when the core body 17 is separated from the first block (see the protruding block 14). Therefore, by effectively utilizing the mold opening space (separated space), the injection molded product (bumper 4) is used.
There is an effect that the second block (see the insert 19) can be removed from the projecting portion (see the bolt boss portion 2) of the second protrusion (see the bolt boss portion 2).

Further, the second block (nest 19
1) is pressed in the direction opposite to the protruding portion, and is pressed by the core body 17 when the mold is closed (see FIGS. 1 and 2) to form the protruding portion forming concave portion 19c. A good protrusion forming recess 19c is formed by the pressing force of the core main body 17 against the urging force of the spring 21, and when the mold is opened (see FIG. 5), the urging force in the direction opposite to the protruding portion is generated. There is an effect that the second block (see the insert 19) can be automatically removed from the protrusion (see the bolt boss 2) of the molded product (see the bumper 4). In short, by effectively utilizing the operations of closing and opening the mold, the formation of the concave portion 19c and the removal of the mold of the second block (see the insert 19) from the projecting portion (see the bolt boss portion 2) can be performed.

In addition, since the ejector pin (see ejector core pin 27) for projecting the molded product penetrates through the second block (see nest 19), the ejector pin (see ejector core pin 27) is used for the second block (see nest 1).
Of course, it can also serve as the sliding guide of 9).
At the time of ejecting, a portion that is easily bitten (a protruding portion of a molded product) can be directly pushed by the ejector pin (see the ejector core pin 27), and there is an effect that the releasability can be improved.

Further, since the ejector pin (see ejector core pin 27) has a two-stage projecting structure, the ejector pin (see ejector core pin 27) can be used to project a molded product (see bumper 4) in two steps (see FIG. 7, FIG. 7). In FIG. 8, a gap g can be formed between the first block (see the protruding block 14) and the molded product (product). As a result, there is an effect that the releasability can be further improved, and a reliable and good release can be performed.

Further, in an injection molded product having an undercut portion 3 (see bumper 4), an inclined core for molding the undercut portion (see push-up core 16) is provided. The core (see the push-up core 16) moves in the inclined direction and comes off the undercut portion 3. For this reason, there is an effect that the molded product having the undercut portion 3 (see the bumper 4) can be surely released. In correspondence between the configuration of the present invention and the above-described embodiment, the injection molded product of the present invention corresponds to the bumper 4, and similarly, the protrusion of the injection molded product corresponds to the bolt boss 2, and the block is , Corresponding to the protruding block 14 as the first block and the nest 19 as the second block,
The moving means corresponds to the coil spring 21 as a mechanical moving means, the first block corresponds to the protruding block 14, the second block corresponds to the nest 19, and the ejector pin corresponds to the ejector core pin 27. The inclined core corresponds to the push-up core 16, the recess corresponds to the recess 19c, and the guide means corresponds to the guide pin 15,
The present invention is not limited only to the configuration of the above embodiment.

For example, the space 18 of the protruding block 14
May be formed smaller than that of the illustrated embodiment, and the moving means may be constituted by an electric actuator that moves the small nest 19 to the side opposite to the protruding portion before opening the mold. . Further, the present invention may be applied to the molding of other injection molded products instead of the above-mentioned resin bumper for vehicles, and the above-mentioned projecting portion may be a reinforcing rib or other various projecting portions instead of the bolt boss portion 2. .

In addition, if the ejector pin has a two-stage projecting structure of a seesaw type as shown in the illustrated embodiment, it can be inexpensively constructed. However, this two-stage projecting structure can be replaced by an electric drive or a hydraulic drive instead of the seesaw type. A two-stage projecting structure may be used.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an injection molding apparatus of the present invention in a mold closed state.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a partially enlarged view showing a relationship between a protruding portion of an injection molded product and an ejector core pin.

FIG. 4 is a cross-sectional view showing a downward movement of the nest when the mold of the injection molding apparatus is opened.

FIG. 5 is an enlarged sectional view of a main part of FIG. 4;

FIG. 6 is a cross-sectional view showing the injection molding device in a one-step projecting state.

FIG. 7 is a sectional view showing a two-stage projecting state of the injection molding apparatus.

FIG. 8 is an enlarged sectional view of a main part of FIG. 7;

FIG. 9 is an explanatory view showing deformation of a molded product by a conventional injection molding apparatus.

FIG. 10 is a sectional view showing a conventional injection molding apparatus.

[Explanation of symbols]

 2 Bolt boss part 3 Undercut part 4 Bumper 5 Upper die 6 Lower die 9 Eject plate 14 Projection block 15 Guide pin 16 Push-up core 17 Core body 19 Nest 19c Recess 21 21 Coil spring 25 Seesaw lever 27 Ejector core pin

Claims (6)

[Claims] 1. An injection molding apparatus for forming an injection molded article having a projection by a lower mold and an upper mold having a core body and a block, wherein the block forms a first block and the projection. An injection molding apparatus comprising: a second block having a recess and slidable with respect to the first block; and moving means for moving the second block to the side opposite to the protruding portion before opening the mold. 2. The injection molding apparatus according to claim 1, wherein the moving means moves the second block toward the side opposite to the protruding portion when the core body is separated from the first block. 3. The projection for forming a projection is formed in cooperation with the first block when the second block is urged in the direction opposite to the projection and is pressed by the core body when the mold is closed. Injection molding equipment. 4. An injection molding apparatus according to claim 2, wherein an ejector pin for projecting a molded product is provided through the second block. 5. A lower end of said ejector pin abuts one end of a seesaw lever provided on an ejector plate,
5. The injection molding apparatus according to claim 4, wherein the ejector pin projects in two steps by the action of the seesaw lever. 6. An injection molding apparatus for forming an injection-molded article having an undercut portion, comprising: an inclined core for forming the undercut portion; and a guide for moving the inclined core in an oblique direction away from the undercut portion. An injection molding apparatus provided with a means.