JPS6256113A - Folding type molding core - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Industrial application fields> The present invention relates to a foldable molding core.

<Prior Art> When molding a can with two inward lips, if the lips are small and the plastic material can be stretched, the molded can can be peeled off from the core. I can do it. However, if the degree of protrusion of the lip is large or the lip is damaged when the plastic material is fully stretched, it is necessary to use a collapsible core.

Collapsible molding cores are known which, when assembled, form a cylindrical surface around which an article is molded.

An example of a foldable molding core consists of three main parts. Two of these main members are rings with axially extending segments of sector-shaped cross section. The segments of one ring are interlaced with the segments of the other ring to interlock the fingers of the hand. When the two sets of segments are combined, they form a continuous ring, and the central member slidably disposed within the ring completes the cylindrical shape of the core. The mating surfaces of the two ring segments are such that when the cylindrical center member is withdrawn axially, the inner ring segments are not obstructed by the lip formed in the molding, thereby allowing these segments to be withdrawn. It is sloped in the radial direction of the cylinder so that the segments can be moved a sufficient distance radially inwardly of the ring. After extracting the inner segments, they can also be extracted by moving radially inward of the outer ring segments.

Each ring segment bends to remove all disturbances introduced by the lip formed in the molding.
It is usually resiliently attached at one end to a common support member.

Various collapsible molding cores are also known which consist of t2 sets of segments assembled together, a frustoconically shaped central member and an outer case divided to form the whole.

These cores (e.g. British Patent No. 1.045.350
and GB 1,594,207 and GB 4100.172 and GB 2,132,934), the 2 m segments are moved axially with respect to each other and do not. instead of,
The segments of one set act as a wedge between the segments of the other set, and as the core is removed, both sets of segments return radially at the same time. This diaphragm acts as a radial wedge when one set of segments is folded, and the other set of segments forms in the molded part as much as necessary to remove any disturbance caused by the diaphragm. It can be returned to the position.

Other collapsible molding cores of lumps are also described in GB 2,135,236.

In this core, there are two pairs of segments keyed to the four sides of a four-sided pyramid-shaped tapered core. The keyway connected to the first pair of segments allows the second pair of segments to be moved without fully moving the first pair of segments.
It has a radial gap that allows the central member to be removed by moving the pairs of segments' in the radial direction. The second pair of segments is radially folded and then extracted with the central member.

On the other hand, the segments of the first pair remain in the hollow part of the mold and are moved radially as the central member is removed. The gap in the keyway is accommodated by the initial withdrawal of the central member. Finally, after the first pair of segments has been moved radially inward, thereby removing the obstruction posed by the molded part, the first pair of segments is also pulled axially out of the convex mold. .

<Problems to be Solved by the Invention> The construction of the foldable molding core described at the beginning has several drawbacks that must be taken into account. The first drawback is
Since the segments are pivoted to a common support member, the permissible travel of the segment closest to this support member is:
Therefore, there are severe restrictions on the width of the 7'CIJ tube formed in the molded product.

A second drawback is that the central member is completely withdrawn in the axial direction.
Therefore, the inner segment cannot be folded in the radial direction,
Additionally, the inner segment is completely removed and the outer segment cannot be folded inwards. Therefore, the amount of movement required to extract the molded article from the mold is twice the length of the molded article. In other words, the length of the core from which the molded article can be extracted is three times the length of the core when it is in the mold.

In some molded articles, such as 5 ton paint cans, the amount of movement described above is not readily tolerated. However, in either case, the main component ffi 7 is removed from the inside of the molded product.
The time required for the 11th extraction is too long and is not acceptable from a profit standpoint. Of course, if the extraction of the large folding molding core is to be carried out automatically, the entire control system must be configured so that the three operations can be carried out in sequence. This unnecessarily increases the overall complexity of the control system, resulting in increased cost and reduced reliability.

According to the large folding core described below, when the segments of the large folding core always form the same axial plane, the degree of folding is limited. This is because the total allowable movement of the outer segment is only equal to the outer thickness of the inner segment, which acts as a wedge. These segments must taper radially outward if they are to be foldable. Therefore, if the total thickness of the segment as a wedge is to be increased at the radially outer end of the segment, the total thickness of the segment must also be increased at the radially inner end of the segment. This also prevents radial withdrawal of segments as wedges as they come into contact with others.

In the configuration of the large folding molding core described last, the number of segments is 4, which limits the total degree of folding of the core.
limited to individuals. Also, since all the segments are keyed to the tapered center member, the degree of folding is limited by the amount of clearance in the keyways that join all the segments of the first light to the center member.

Therefore, all attempts to create large folding molding cores are constrained, for different reasons, in the degree of folding that can be achieved for a given diameter. Furthermore, as mentioned above, there were also problems with the function of some of the cores. On the other hand, cores with segments that are movable only in the radial direction have a complicated structure, and the segments rub against each other during use, causing reliability problems.

The object of the present invention is to provide a large folding molding core which overcomes at least some of the drawbacks mentioned above.

Elaborate means to solve all problems> The large folding molding core consists of a first set of inner segments and a second set of inner segments that work together to form a continuous ring ring.
The surface of the core is completed by a set of outer segments and a tapered center member disposed inside the ring. The tapered center member is axially movable relative to both sets of segments, and both sets of segments are axially movable relative to each other. The cores are mounted on a 31-piece device that is mutually movable in the axial direction of the cores. The first of these devices is supported by a tapered central member.

Is the second device the first support plate? and a first set of segments is radially movably mounted on the first support plate. The third device has a second support plate on which a second set of segments is radially movably mounted.

Also provided are first guide means for coupling the first and second devices. The first guide means causes the first set of segments to move radially on the first support plate in response to axial movement of the first device relative to the second device.

Similarly, second guide means are provided which couple the second and third devices i. The second guide means is configured such that the second device
Corresponding to the axial movement relative to the device, the segments of the second set are all radially moved on the second support plate.

According to a first embodiment of the invention, three devices are coupled to each other by mechanical interlocking devices, ensuring complete synchronization of the movement of each device.

According to a second embodiment of the invention, the above-mentioned mechanical interlocking device is supported by a second device and is pivotally arranged with a movable device on the companion cam and the other two devices. and a cam follower provided on the arm.

According to a third embodiment of the invention, a segment of the second device engages a mortise groove provided in the tapered center member of the first device, and a segment of the third device engages a mortise provided in the plate of the second device. The movement of the two sets of segments is automatically synchronized with the relative movement of the three devices, and the force required to fully collapse or expand the core is reduced to three steps. Only the force required to move the same devices relative to each other is required.

According to a fourth embodiment of the present invention, a cooling water circulation circuit is provided completely through the segments and the tapered center member,
Cool all metal surfaces that come into contact with the molded product.

Preferably, the first set of segments is radially tapered to a narrower side near its circumference and axially tapered to a narrower side closer to its free end. Due to the axial and radial taper of the first set of segments, the clearance provided for folding of the second m segments increases for a given mutual movement.

<Operations and Effects of the Invention> Since the radial and axial movements of the segments occur simultaneously, and because the central member is conical rather than cylindrical, the central member moves into the segment before the segments begin to move in the radial direction. There is no need to avoid interference from This is the case in prior art structures in which all segments are axially movable relative to each other. Therefore, the folding of the core in the radial direction '\' is not affected by the length of the core in the present invention. Disturbance from lip formed on molded product? Since it is not affected, K suffices with very little movement; the amount of movement required depends only on the width of the lip that has to be passed.

In addition, compared to the case where all segments and members are always aligned in the same axial plane, in the core of the present invention, the segments can be extracted in the axial direction without colliding with each other, so that The thickest wedge-shaped segment can be used entirely.

The segments do not need to be made of elastic material since they are guided to move radially and do not bend.

-! Additionally, there is no limit to the extent to which the segments can move laterally in order to remove any disturbances posed by the lip formed on the molded article. Since the segment moves radially over its entire length, it hardly matters whether the lip formed in the molded part is near the open end or the closed end of the molded part.

The segments are mechanically interlocked with the movement of the three devices (
For example, gearing, cams and guides) are particularly desirable. In this way, the entire core can be folded and expanded using only the force that separates and connects all three devices.

<Examples> Examples of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the foldable molding core of the present invention comprises three relatively movable devices 10.
and 210. Each device 1110.11
0 and 210 have plates 12° 112 and 212. These three plates 12° 112 and 212 are precisely guided relative to each other in a synchronous manner. The synchronous operation will be described later. Boards 12, 112 and 212 are board 1
It is guided in the axial direction by a rod fixed to 2 and holes provided in the other two plates 112 and 212.

These rods and holes are omitted from illustration for clarity.

The first plate 12 has a fixed cone 14. Around this cone 14 are provided three mortises 16 with a constant circumferential spacing. The groove 16 is a groove having a T-shaped cross section. However, although the slider assembled in the groove 16 can slide along the groove 16, it cannot be pulled out in the radial direction of the cone 14. A lead portion 16a is provided at the starting end of the groove 16.

This lead portion 16a serves as a companion for assembling the slider into the mortise groove 16. The axial surface 18 of the cone 140 defines the center of the surface of the foldable molding core.

The plate 112 of the device 110 has a total of 31 radially extending guide slots 114. These guide slots 1
14 are arranged symmetrically around central hole 115 and aligned with mortise groove 16 . Only one guide slot 114 is shown in FIG. 1 for the sake of clarity. The other two kite slots are also identical to the illustrated guide slot 114 and are shown in dashed lines.

The base 116a of each guide slot 114KH1 inner segment 116 is slidably installed. The inner segment 116 constitutes a portion of the entire cylindrical surface of the folding molding core. Each base 116a is provided with a slider 116c that is incorporated into the mortise 16 of the cone 14 of the device 10.

A T-shaped cross section of the base 116a is incorporated into the guide slot 114. When the plate 12 is moved towards the plate 112, the inner segments 116 are moved towards the inner segments 11
6 slides along the mortise groove 16 of the cone 14, it moves radially outward along the guide slot 114.

Inner segment 1 that partially constitutes the foldable molding core
The surface of 16 consists of a shaft end surface 116b and a surface 116d having a tapered segment shape (part of a cylinder). The angle formed by the segment 116 tapers toward the free end in the axial direction.

The radially inner surface of each inner segment 116 includes two plates 1
When 2 and 112 are fully folded relative to each other, they completely form a conical surface that fits into the cone 14.

The side surface 116e of the inner segment 116 is also provided with a groove that tapers outward in the radial direction, as shown in FIG. Therefore, when the cone 14 is withdrawn, the inner segment 116 folds radially inward without interference from the outer segment, which will be described below.

Mounted at an angle to the plate 112 are three guide bins 118 (again, only one guide bin shown), one in each of the guide slots 1-114 in the radial direction. Opposite: set on the sea urchin. The purpose of guide bin 118 will be discussed below in connection with the discussion regarding third mounting #210.

The third device 210 consists of two plates 212 fixed to each other.
and has 214 karat gold. The plate 212 has three slots 2
It has 15. These slots 215 are connected to the central hole 21
7 and are arranged symmetrically around the guide bin 118
Align. Slot 215 receives the bases 2f6 of three outer segments 216. The base 216a slides along the six slots 215 that slide in the radial direction, and the base 216a is provided with an inclined hole 219.

Slanted hole 219 receives guide bin 118.

Thus, radial movement of outer segment 216 is caused by mutual axial movement of plates 112 and 212.

Each outer segment 216 has an end surface 216bt-.

The end surface 216b constitutes a part of the end surface of the foldable molding core (see FIG. 3). The outer cylindrical surface 216d is a part of the cylindrical surface, and tapers toward the plate 212. That is, the circumferential length of the outer cylindrical surface 216d increases toward the free end to compensate for the taper of the inner segment 116. Inner cylindrical surface 216
C fits the surface of the cone 14 when the three devices 10.degree. 110 and 210 are in contact with each other to complete the surface of the cone 14, as shown in FIG. Similarly, since side surface 216e is tapered radially inwardly as shown in FIG. 3, inner segment 116 contracts by moving radially inwardly. be able to.

Plate 214, one end of the mold? Form. The thickness of the plate 214 extends toward the folded portion 218 of the outer segment 216. The folded portion 28 is for forming a lip at one end of the molded product.

With the slider 116c installed in the mortise groove 16 and the guide bin 118 installed in the hole 219 of the base 216a of the outer segment 216, the three mounting #10, 110
Assuming that and 210 are maximally folded into each other,
Cone 14. The length of the inner segment I-116 and the outer segment 216 is the length of the cone 14. inner segment 11
The end faces of the outer segments 216 and 216 are coplanar with each other and are configured to mate exactly as shown in FIG. 3 to define the end faces of the core. The cylindrical surfaces of the core are defined by the outer cylindrical surfaces of inner segment 116 and outer segment 216, respectively. A small fold or diameter section is formed at one end of the outer cylindrical surface of the core by a fold 218 of the outer segment 216. However, such a small diameter portion can be provided anywhere along the length of the segment and is not necessarily limited to the ends.

In use, the outer part of the mold (not shown) can e.g.
As in the illustrated example, a molding hollow having the shape of a paint can is disposed around a collapsible core. After the article has been formed, the core is folded. To this, Eli
The part of the article formed on the folded portion does not interfere with the large diameter outer surface of the core. This operation is performed by separating all three devices.

First, the device 10 is separated from the other two devices 110 and 210. At this time, there is almost no mutual movement between devices 110 and 210. As the cone 14 is extracted, the slider 116 slides along the groove 116 and moves radially inward. inner segment 1
16 is tapered outwardly when viewed in the axial direction so that movement of the inner segment 116 is not impeded by the outer segment 216. In this way, the inward movement of the inner segment 116 occurs simultaneously with the withdrawal of the cone 14.

When the inner segments 116 are cleared of the obstruction posed by the lip formed on the molded part, they are removed axially even though the cone 14 is not completely removed from the center of the core. start. Then, when the inner segment 116 is moved sufficiently radially, the two devices 110 and 210 are separated. Inner segment 116 is longitudinally tapered so that it can be easily removed from outer segment 216. As the device 10.1TO tool 210 is separated, the bin 118 cooperates with the hole 219 to move the outer segment 216 radially inward. This radial inward movement of outer segment 216 occurs simultaneously with the withdrawal of inner segment 116.

Once fully extracted, the outer segment 216 collapses radially inward.

This allows the molded part to be removed from the core without interference.

The amount of movement required is determined by the width of the obstruction to be avoided, the angle of the cone and the angle of the tilt guide bin 118. This required amount of movement is independent of the axial length of the core. This is different from the structure of the molding core according to the prior art.

In conventional molding cores, the center member is almost cylindrical rather than conical, and before the outer segments are fully ribbed, the center member is first moved a full distance in the axial direction of the core;
The inner segment must then be moved the same distance.

In order for all three devices 10, 110 and 210 to move properly, an interlocking device such as that shown in FIG. 2 must be employed. This interlocking device consists of four levers 310
, 312.314 Movable VC structure consisting of 616
Have deposit. Lever 314 work 616 is the bottle 615
It is connected to the plate 12 by. Similarly, lever 61
The workpiece 312 is connected to the plate 212 by a pin 311. C-310 and 614 are coupled by a first cam follower bin 313. lever 61
2 and 616 are connected by a second cam driven bin 317. The cam driven bins 313 and 317 are
It moves along L-shaped cams 320 and 322 provided on the plate 112.

When the plate 12 is fixed and a force is applied to the plate 212, first, the cam follower pin 313 and
20 and 322.

Therefore, there is almost no mutual movement between the plates 212 and 112, and they move together in the direction of separation from the plate 12. When the cam driven bins 313 and 617 reach the corners of the L-shaped cams 620 and 622,
The mobile device is folded inwardly. Next to this, plates 12 and 1
There is no mutual movement between plates 112 and 2.
12 is separated by 5.

In this way, one beak that operates the movable fittings: C, therefore, three fittings! 10.110 Work 210: t, separate and move together again. With E7, the segments automatically move 5 synchronously to assemble or fold the core.

In the preferred embodiments described in the specification and shown in the drawings:
Each segment has a slider-like base metal for radial guidance. The radially outer end surface of each slider-shaped base can be touched by hand no matter what state the mold is in. Therefore, cooling water passages can be formed within each segment. Further, the flexible pipe may be attached to the end face of the entire radially outer end. This pipe functions as a cooling water supply and recovery pipe. Since the amount of movement of the core parts is small, there is no need to shrink the entire pipe that much. 19. The pipe has no risk of becoming tangled within the mechanical parts of the mold.

Furthermore, by cooling the cone 14t, all surfaces that come into contact with the molded product can be cooled by circulating cooling water. This overall cooling system improvement can also reduce the cycle time required to mold an article.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing the main parts of the foldable molding core of the present invention. FIG. 2 is a schematic plan view of an interlock device ensuring synchronous movement of the three devices shown in FIG. 1; FIG. 3 is an end view of the molding core. 10.110 and 210... device, 14... tapered central member, 16 and 116c... first guide means, 112... first support plate, 116... inner segment, 212... Second support plate, 216...outer segment.

Claims (1)

[Claims] The first and second parts are combined so as to cooperate to form a continuous ring.
one set of segments and a second set of segments and a tapered center member disposed within the annulus to complete the surface of the core, the tapered center member being axially disposed relative to both sets of segments. In a foldable molding core in which the segments of both sets are movable relative to each other in the axial direction, a) the core has three devices mutually movable in the axial direction of the core; a first device supporting the tapered center member, a second device having a first support plate, and a first set of segments radially movably mounted on the first support plate; the third device has a second support plate on which the second set of segments is radially movably mounted; b) a first guide coupling the first and second devices; Means is provided, the first guide means is configured such that the first device
c) second guide means are provided for coupling the second and third devices, c) moving the first set of segments radially on the first support plate in response to the axial movement relative to the device; , wherein the second guide means moves the second set of segments radially on the second support plate in response to axial movement of the second device relative to the third device. Foldable molding core.