JP3373550B2 - Undercut processing type - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an undercut treatment mold used for molding a molded product having a plurality of undercut portions.

[0002]

2. Description of the Related Art In a mold for molding a molded product having an undercut portion, a slide core is provided in an inclined manner.
When the molded product is ejected, part of the mold is allowed to escape obliquely. FIG. 15 shows an undercut-processed mold described in Japanese Utility Model Laid-Open No. 1-83518.
A plurality of slide cores 101 and 102 are set in 0. Each slide core 101, 102 is a molded product 200.
Of the inclined rods 103 and 10 respectively.
4 is connected to the ejection plate 110 for ejecting the molded product 200. Inclined rod 103, 104
Is relative to the protruding direction of the molded product (upward in the illustrated example)
They are tilted in the same direction, but the tilt angles are different.
The lower ends of the tilt rods 103 and 104 are connected to the ejection plate 110 via slide blocks 105 and 106, and the slide blocks 105 and 106 can slide in the same direction (rightward) when the ejection plate is ejected. Has become.

In the above structure, when the ejection plate 110 moves upward, the inclined rods 103 and 104 move obliquely upward via the slide locks 105 and 106, so that the slide cores 101 and 102 are pushed out from the die main body. As a result, the molded product 200 is ejected, but the slide cores 101 and 102 move in an oblique direction, so that the undercuts 201 and 202 and the slide core 1
The molded product 200 can be released from 01 and 102.

FIG. 16 shows a core rod 12 of the undercut type disclosed in Japanese Patent Publication No. 2-61892.
A plurality of slide cores 121 and 122 are arranged around 0. The outer peripheral surface of the core rod 120 is a molded product 200.
The taper surface is such that the diameter thereof gradually decreases along the protruding direction of the slide cores 121 and 122, and the slide cores 121 and 122 slide in the protruding direction of the molded product along the tapered surface.

In order to perform such sliding, a dovetail groove 123 is formed on the outer peripheral surface of the core rod 120 in the longitudinal direction,
The slide cores 121 and 122 are engaged with the dovetail grooves 123, respectively. This processing type is the slide core 12
When 1,122 slides in the protruding direction, dovetail 12
Since the tip end portions of the molded article 200 are guided by the guide 3 and move toward each other, that is, in the direction of reducing the diameter, the molded product 200 having the undercut portion can be released from the mold.

17 and 18 are shown in Japanese Patent Application Laid-Open No. 62-1569.
The undercut processing type described in Japanese Patent No. 18
A plurality of slide cores 131 and 132 are slidably provided around a main core 130 whose diameter gradually decreases toward the tip. As the slide cores 131 and 132 are moved away from the molded product 200 in accordance with this slide, the main core 130 and the slide cores 131,
A dovetail groove 133 that engages with 132 is formed.

[0007]

In the conventional undercut processing type shown in FIG. 15, since the slide cores 101 and 102 slide in the same direction, the undercut formation site is limited to one direction. There is. In order to form this undercut portion in multiple directions, it is necessary to slide the slide core in different directions.
In the processing type shown in FIG. 5, the slant rods 103 and 104 and the slide blocks 105 and 106 interfere with each other and cannot operate.

On the other hand, in the undercut type shown in FIGS. 16, 17, and 18, since the slide is moved,
A complicated dovetail is required, and there is a problem that its processing becomes troublesome.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an undercut processing die which can form an undercut portion extending in multiple directions and is easily processed.

[0010]

In order to achieve the above object, the undercut processing mold of the present invention comprises a plurality of slide cores for molding a plurality of undercut portions provided in a molded article, and the plurality of slide cores. A protruding plate that supports the base ends of the slide cores at different heights while inclining the slide core in different directions with respect to the protruding direction of the molded product,
Slide means for slidingly moving the plurality of slide cores in different directions according to the movement of the protruding plate in the protruding direction. In this case, the protruding plate is composed of a plurality of members having different movement amounts,
The respective members may be connected by the engagement mechanism, and the connection may be released when the respective members reach the set movement amount.

[0011]

In the above construction, since the slide core is slidable in different directions, it is possible to form an undercut portion extending in multiple directions. Further, since the heights of the receiving surfaces of the slide cores are different, they do not interfere with each other when the slide cores slide.

[0012]

First Embodiment FIGS. 1 and 2 show a first embodiment of the present invention. Slide cores 3 and 4 are inserted into a core 2 for forming the outer shape of the molded product 1. Each slide core 3,4
Is for molding the undercut portions 1a, 1b of the molded product 1, and a molding portion therefor is formed at a portion corresponding to the undercut portions 1a, 1b. In this embodiment, the undercut portions 1a and 1b are formed in different directions which are substantially orthogonal to each other.

In order to form the undercut portions 1a and 1b in different directions, the slide cores 3 and 4 are inclined in different directions. In this embodiment, the slide core 3 is tilted in the left-right direction and the slide core 4 is tilted in the front-rear direction (paper-sheet penetrating direction), so that the tilt directions of the slide cores 3 and 4 are substantially orthogonal to each other. There is.

Reference numeral 10 denotes an ejection plate that moves in the ejection direction to release the molded product 1, and has a structure in which a lower ejection plate 11 and an upper ejection plate 12 are laminated. Each of the slide cores 3 and 4 has the protruding plate 10
The lower end is supported by. In this case, one slide core 3 is supported by the lower projecting plate 11, and the other slide core 4 is supported by the upper projecting plate 12, so that the height of the receiving surfaces of the slide cores 3 and 4 is increased. Is different.

The lower ends of the slide cores 3 and 4 are supported by the corresponding protruding plates 11 and 12, and the slide cores 3 and 4 are supported by the protruding plates 11 and 12, respectively. It is possible to slide.

In order to perform such a slide, each slide core 3, 4 is provided with core pins 5, 6 at the lower end portion. The long groove 7 as a slide means into which the core pin 5 of the slide core 3 is slidably inserted has an upper protrusion plate 1.
2 is formed. On the other hand, a receiving block 8 is provided on the upper protruding plate 12 that supports the slide core 4, and a long groove (not shown) into which the core pin 6 of the slide core 4 is slidably inserted is formed in the receiving block 8. The long grooves into which the core pins 5 and 6 are inserted are provided in the orthogonal direction, whereby the lower ends of the slide cores 3 and 4 slide in the orthogonal direction.

In the above structure, after the molded product 1 is molded, the parting surface of the mold is opened, and the ejecting rod (not shown) is operated to move the ejecting plate 10 in the ejecting direction. By this movement, the slide cores 3 and 4 move in the protruding direction of the molded product 1, but since the slide core 3 is inclined in the left-right direction and the slide core 4 is inclined in the front-rear direction, the slide cores 3 are inclined in the respective inclination directions. Slide to move. By this slide movement, the slide cores 3 and 4 are molded products 1
While protruding the undercut portion 1a of the molded product 1,
Since it is separated from 1b, the molded product can be released from the mold.

In this embodiment, since the slide cores 3 and 4 slide in different directions, the undercut portions 1a and 1b in different directions can be released. Further, since the heights of the receiving surfaces of the slide cores 3 and 4 are different from each other, the slide cores 3 and 4 do not interfere with each other at the time of the slide, so that the molded products can be reliably separated. Further, since complicated processing such as a dovetail groove is not required and the workability is good, and since no angular pin or locking block is required, the structure can be simplified and the size can be reduced.

[0019]

Second Embodiment FIGS. 3 to 7 show a second embodiment of the present invention. The second embodiment is used to form a lens barrel of a camera, and the movable mold 20 has a movable insert 21.
Are fixed by screws 22 (see FIG. 3).

3 and 4, 23 is a slide core forming a helicoid portion, and 24 is a slide core forming a corresponding helicoid portion. In addition to these, the movable side insert 21 has a slide core shown in FIG. As shown in, a plurality of slide cores are arranged to cover the movable side insert 21.
These slide cores are provided so as to be inclined with respect to the movable side mold plate 20 in mutually different directions, but the slide cores (for example, the slide cores 23 and 24) at the opposing positions are
The inclination angle with respect to the movable insert 21 is different.

The lower end of each slide core is supported by the protruding plate 10, but a pair of opposed slide cores (for example, slide cores 23 and 24) have different receiving surfaces. In this embodiment, there are three pairs of slide cores, and the heights of these receiving surfaces are different, so that the ejection plate 10 has a three-stage configuration. In FIG. 3, the slide core 23 is supported by the second protrusion plate 14, and the slide core 24 is supported by the third protrusion plate 16. These slide cores 23 and 24 are the receiving blocks 2 provided on the corresponding protruding plates 14 and 15.
5, 26, and the core pins 27, 2
8 is slidably inserted into long grooves 25a and 26a as sliding means of the receiving blocks 25 and 26.

FIGS. 6 and 7 show the support structure of the lower end portion of the slide core 23, which is similarly applied to the slide core 24 and other slide cores.
In these figures, the receiving block 25 is provided from the second projecting plate 14 to the first projecting plate 13, and the core pin 27 of the slide core 23 can slide in the long groove 25 a formed in the receiving block 25. Has been inserted into. In the above structure, the ejection plate 10 is moved in the ejection direction, and each slide core is slid in the inclination direction while moving in the same direction. Since this slide movement is performed in the direction in which the tips of the slide cores approach each other (the slide cores 23 and 24 in FIG. 3 are in the directions of the arrows in FIG. 3), all the slide cores move away from the corresponding undercut portions, Thereby, the molded product 1 can be released from the mold.

The present embodiment as described above has the same function and effect as the first embodiment, but has the effect of releasing the mold even when the undercut portion is on the entire circumference of the molded product. In addition,
In this embodiment, the clearance between the slide cores 23, 24 and the movable insert 21 can be adjusted by changing the thickness of the receiving blocks 25, 26.

[0024]

[Third Embodiment] FIGS. 8 to 10 show a third embodiment of the present invention for forming a lens barrel of a camera, and the same elements as those in the second embodiment are designated by the same reference numerals. This Example 3
In, the protruding plate 10 is formed in a plurality of stages. That is, the ejection plate 10 includes an upper ejection member 31 and a lower ejection member 32.
32 has a two-stage structure. And the slide core 23
The receiving block 25, which supports the lower end of the slide core 24 and has the core pin 27 slidably inserted therein, is provided on the lower protruding member 32, supports the lower end of the slide core 24, and has the core pin 28 slidably inserted therein. The receiving block 26 is provided on the upper protruding member 31. As a result, the slide cores 23, 24 are supported by the protruding plate 10 in a state where the heights of their receiving surfaces are different. Reference numeral 33 denotes a movable side mounting plate provided below the lower protruding member 32. The movable side mounting plate 33 and the lower protruding member 32 are connected to each other through a protruding hole 34 into which a protruding rod (not shown) is inserted. Has been formed.

The ejecting plate 10 is provided with an engaging mechanism 40 for connecting the upper ejecting member 31 and the lower ejecting member 32. The engaging device groove 40 is provided with a hook arm 41 rotatably attached to the upper protruding member 31 via a pin 42, and a lower protruding member 32 so that a lower end portion of the hook arm 41 is detachably engaged. And a hook pin 43 attached to the. Reference numeral 44 denotes a spring for urging the hook arm 41 so that the hook arm 41 is disengaged from the engagement with the hook pin 43. Reference numeral 45 is in sliding contact with the end surface of the hook arm 41 on the side opposite to the spring 44 to resist the urging of the spring 44.
It is a lock bar that maintains the engagement state of the hook arm 41 and the hook pin 43. The lock bar 45 is erected on the upper surface of the movable side mounting plate 33 so as to have a predetermined length.

Further, in this embodiment, the movable side mounting plate 3
3, a stopper pin 46 is provided upright. The stopper pin 46 passes through the lower protrusion member 32 and the upper protrusion member 31, and the upper end portion thereof forms a flange-shaped head portion 46a. In addition, the lower protruding member 32
The insertion hole 32a of the stopper pin 46 in the
It has a smaller diameter than The stopper pin 46 is
The movement amount of the lower protrusion member 32 of the protrusion plate 10 is regulated within a set range.

Next, the operation of this embodiment will be described. At the time of molding a molded product (not shown), the hook arm 41 of the engaging mechanism 40 engages with the hook pin 43 as shown in FIG.
And are connected. After the molded product is molded, the ejection rod moves up and enters the ejection hole 34 to press the lower surface of the upper ejection member 31. As a result, the upper protrusion member 31 and the lower protrusion member 32 move integrally in the protrusion direction, so that the slide cores 23 and 24 slide in the inclination direction as shown by the arrows in FIG. Therefore, the slide cores 23 and 24 separate from the undercut portion while projecting the molded product.

When the ejecting rod further rises, the upper surface of the lower ejecting member 32 is moved to the head portion 46 of the stopper pin 46.
Since it comes into contact with a, its movement stops. At this time, the hook arm 41 of the engagement mechanism 40 has reached the upper limit of the lock bar 45, and is rotated clockwise by the urging force of the spring 44. As a result, the hook arm 41 is disengaged from the hook pin 43, and the connection between the upper protruding member 31 and the lower protruding member 32 is released. Therefore, only the upper protruding member 31 moves in the protruding direction, and the slight core 24 supported by the upper protruding member 31 slides in the tilt direction shown by the arrow in FIG. 10 while continuing to move in the protruding direction.

Therefore, in this embodiment, the slide core 24
Since it can be ejected longer than in the second embodiment, the molded product can be reliably released from the mold. In this embodiment, the engagement of the hook arm 41 may be released by a cam, and in this case, the spring 41 and the lock bar 45 can be omitted.

11 and 12 show a modified example of the engaging mechanism 40, in which the protrusion rod 5 is provided on the lower surface of the upper protrusion 31.
1 is fastened with screws. On the other hand, the lower protruding member 3
A sleeve 52, through which the protruding rod 51 is inserted, is provided at 2, and an engaging hole 53 is formed in this sleeve 52. Further, the engaging hole 5 in the protruding rod 51
An engaging pin 55 biased in a protruding direction by a spring 54 is provided inside a portion facing the member 3, thereby connecting the upper protruding member 31 and the lower protruding member 32.

In such a structure, when the ejecting mechanism (not shown) of the molding apparatus presses the ejecting rod 51, the upper ejecting member 31 and the lower ejecting member 32 move integrally in the ejecting direction. Then, at the same time when the movement of the lower protrusion member 32 is stopped, the engagement pin 55 is disengaged from the engagement with the engagement hole 53.
Only 1 moves.

13 and 14 show a modification in which the slide core 60 is slid. The lower end of the slide core 60 is connected to and supported by the receiving block 82 with a screw 81. The receiving block 62 is a lower protruding plate 63.
Although it is attached to the upper surface, it is formed in a stepped shape, and the upper protruding plate 64 has a stepped groove 6 as a slide means into which the receiving block 62 is slidably inserted.
Have five. Even with such a configuration, since the receiving block 82 slides left and right, the slide core 60
It is possible to slide in the tilt direction.

[0033]

As described above, according to the present invention, since the slide cores are inclined in different directions and are slid in the respective inclination directions, the slide cores do not interfere with each other and a complicated undercut is performed. Even a part can be released from the mold.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the first embodiment at the time of mold release.

FIG. 3 is a sectional view of a second embodiment of the present invention.

FIG. 4 is a partial plan view of FIG.

FIG. 5 is a plan view of FIG.

FIG. 6 is a sectional view of a supporting portion of a slide core.

7 is a sectional view taken along line VII-VII in FIG.

FIG. 8 is a sectional view of a third embodiment of the present invention.

FIG. 9 is a sectional view showing the operation of the third embodiment.

FIG. 10 is a sectional view showing the operation of the third embodiment.

FIG. 11 is a cross-sectional view of a modified example of the engagement mechanism.

FIG. 12 is a sectional view showing the operation of the sectional view of the modified example of the engagement mechanism.

FIG. 13 is a cross-sectional view of a modification of the slide of the slide core.

14 is a cross-sectional view taken along the line AA of FIG.

FIG. 15 is a sectional view of a conventional example.

FIG. 16 is a cross-sectional view of another conventional example.

FIG. 17 is a sectional view of still another conventional example.

FIG. 18 is a sectional view from the side of FIG.

[Explanation of symbols]

1 molded product 1a undercut 1b Undercut part 3 slide core 4 slide core

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-58-134726 (JP, A) Actually opened 63-130210 (JP, U) JP-B-55-48900 (JP, B1) US Pat. , A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B29C 33/00-33/76 B29C 45/26-45/44

Claims (2)

(57) [Claims] 1. A plurality of slide cores for molding a plurality of undercut portions provided in a molded product, and a state in which the plurality of slide cores are inclined in different directions with respect to a protruding direction of the molded product. A protrusion means for supporting the respective base end portions at different heights; and a slide means for slidingly moving the plurality of slide cores in different directions according to the movement of the protrusion board in the protrusion direction. Undercut processing type specially made. 2. The ejection plate is composed of a plurality of members having different movement amounts in the ejection direction, and the members of the ejection plate are mutually engaged by an engagement mechanism that releases the engagement when the set movement amount is reached. The undercut mold according to claim 1, which is connected.