JP2770155B2 - Removal head for preform molded products for plastic bottles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a preform molded article formed by an injection molding machine in a stage prior to enclosing a beverage or the like and blow molding a thin transparent resin bottle displayed at a store, for example. The present invention relates to a head for removing a preform molded product for a plastic bottle which is removed from a mold and transferred to a cooling means.

[0002]

2. Description of the Related Art Generally, thin transparent resin bottles that are used for over-the-counter sales in which beverages or the like are enclosed are thick transparent preform molded products (hereinafter referred to as molded products) molded by an injection molding machine. Manufactured by blow molding. Specifically, a thick transparent molded product is released from a mold of an injection molding machine by a molded product take-out head, cooled, and then molded into a thin transparent resin bottle by blow molding means.

[0003] Thin transparent resin bottles must be literally transparent in order to achieve the purpose of allowing the enclosed beverage to be viewed. Therefore, the molded article is also required to be transparent. However, in the process of releasing the molded article from the mold and cooling, there is a possibility that a cloudy opaque portion called "whitening" is generated. The reason why “whitening” occurs is that the cooling rate of the molded article is low. That is, in the cooling characteristic diagram of the molded product shown in FIG.
As indicated by the broken line V, the cooling rate to be lowered to the vicinity is lower than the limit cooling rate from the point y1 to the point y2 in the forced cooling curve Y indicated by the solid line, and is represented by the forced cooling curve Y and the natural cooling curve Z indicated by the one-dot chain line. This is for invading the enclosed area (diagonal line x2). For this reason, it is necessary to increase the cooling rate of the molded article higher than the limit cooling rate so as to lower the temperature of the molded article to around 40 ° C. in the hatched region x1. Specifically, the temperature of the molded product is set to 80 ° C. within about 20 seconds.
To about 40 ° C.

FIG. 8 shows a conventional molded product take-out head which can satisfy such requirements. In this type of take-out head, a plurality of tubular chucks 2, 2,... Are mounted on the front side of the base 1 so as to protrude horizontally, and these tubular chucks 2, 2,. A base end of the base 1 is rotatably attached to a distal end of the unloader 5 via a pin 6. Therefore, the rotation means (not shown) attached to the unloading machine 5 can reverse the vertical posture shown by the solid line to the horizontal posture shown by the imaginary line, and can reverse the horizontal posture to the vertical posture. Have been. Further, a cooling water passage 7 functioning as a water jacket is formed inside the base 1, and a cooling water supply hose 8A and a cooling water discharge hose 8B for circulating cooling water are attached to the cooling water passage 7, and a cooling water supply hose is provided. 8A is connected to a cooling water supply source (not shown).

[0005] The removal of a molded product by a conventional molded product removal head will be described. . With the operation of the unloader 5, the take-out head is brought close to the molded products 10, 10...
.. Are inserted into the tubular chucks 2, 2,. . Tubular chucks 2, 2,...
The interior is made negative pressure, and the molded articles 10, 10... Are sucked by the tubular chucks 2, 2,. . The removal head 5 is moved in a direction away from the mold 9 by the operation of the removal machine 5, and the molded products 10 are pulled out of the mold 9. That is, the molded articles 10, 10,... Are released. . With the molded products 10, 10,... Being sucked and held, the take-out head is moved by the operation of the take-out machine 5 to the inlet of cooling means (not shown) installed outside the mold 9. . At the entrance of the cooling means, the take-out head is reversed from the vertical posture shown by the solid line to the horizontal posture shown by the imaginary line by the operation of the rotating means, and the suction of the suction means 4 is released, and the molded articles 10, 10,. Are transferred to the inlet of the cooling means, and while the transferred molded articles 10, 10... Are moved from the inlet to the outlet, cooling is performed by, for example, air cooling.

The molded articles 10, 10,... Are adsorbed and held by the cylindrical chucks 2, 2,. Since it is indirectly water-cooled by cooling water while circulating in the passage 7 and is directly air-cooled after being transferred to the cooling means, the cooling rate for lowering the temperature from 80 ° C. to about 40 ° C. The height of the molded product 10,
10 can be reduced within about 20 seconds to prevent "whitening" from occurring.

However, the conventional molded product take-out head is large and heavy because the cooling water passage 7 functioning as a water jacket is formed inside the base 1. Moreover, since the cooling water is constantly circulating in the cooling water passage 7, the weight is further increased. In addition, a cooling water supply hose 8A and a cooling water discharge hose 8B for circulating the cooling water are attached, and a rotating means for reversing or reversing the take-out head is required. The weight will be further increased. In practice,
The weight per one cylindrical chuck 2 is about 1 kg-1.
2 kg. In general, injection molding is configured to mold 12 to 16 molded products 10, 10... Per one shot, and therefore, the weight of a conventional molded product take-out head is 12 kg to 20 kg.

As described above, in the head for taking out a heavy molded product, the moving speed of the take-out machine 5 is limited, and high-speed movement is hindered. For this reason, the removal time of the molded articles 10, 10... Is long, and according to actual measurement, it takes 7 seconds even if the article is moved at the highest speed. Will be hindered. In addition, in the head for removing a heavy molded product, since the inertia is large, it is difficult to stop the head quickly and appropriately at a predetermined position, and there is a possibility that the removal accuracy of the molded products 10, 10,... . Therefore, it is necessary to reduce the moving speed to avoid a decrease in the takeout accuracy, and the takeout time is lengthened also from this point.

[0009]

That is, a conventional head for removing a preform molded product for a plastic bottle is as follows.
Due to the large size and heavy weight, high-speed movement is hindered, and the removal time of a molded product and the molding cycle time by a molding machine are lengthened, thereby preventing improvement in molding efficiency. In addition, since it is difficult to stop quickly and properly at a predetermined position, there is a possibility that the precision of removing a molded product may be reduced.
The moving speed must be reduced to avoid lowering the takeout accuracy, and the takeout time is lengthened from this point as well. In view of the above, the invention according to claim 1 enables high-speed movement by reducing the size and weight, shortens the removal time of a molded product and the molding cycle time by a molding machine, improves molding efficiency, and increases the moving speed. An object of the present invention is to provide a head for taking out a preform molded product for a plastic bottle, which can be quickly and appropriately stopped at a predetermined position without lowering, and can prevent occurrence of "whitening".

[0010]

In order to achieve the above object, the invention according to claim 1 comprises a substrate and a preform molded product which is attached to a front side of the substrate so as to protrude therefrom and connected to an intake means. A chuck capable of detachably adsorbing a bottom portion, and a support member for supporting a body of the preform molded product protruding and attached to a front side of the substrate in the vicinity of the chuck, wherein the support member is heat-resistant. It is characterized by being formed of a heat insulating material having a low conductivity. According to the first aspect of the present invention, the bottom of the molded product immediately after molding is sucked by the chuck, and the body of the molded product is released by being supported by the supporting member formed of the heat insulating material having a low thermal conductivity. Since it can be moved to the cooling means of the next step and transferred, the temperature reduction of the molded article during the movement is suppressed by the heat retaining effect of the support member. Therefore, the formation of the cooling water passage functioning as a water jacket can be omitted, and naturally, the cooling water can be constantly circulated, so that downsizing, weight reduction, and simplification of the structure can be achieved.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; 1 is a front view, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, FIG. 3 is a bottom view of FIG. 1, and FIG. 4 is an enlarged cross-sectional view showing a state of attachment of a chuck and a support member. The same or corresponding parts as those of the conventional example are denoted by the same reference numerals and described. 1 to 4
, 1 denotes a thin substrate, and a plurality of (16) chucks 2, 2,... Formed by suction cups are attached to the front side of the substrate 1 to protrude.
Are connected to a suction means 4 via a suction tube 3 respectively. Are molded from an elastic material such as rubber or synthetic resin, and the base side thereof is airtightly fitted to the distal end of the intake cylinder 12 and integrally joined to the cylinder 12. The intake cylinder 12 is axially movably inserted through a through hole 11 formed in the substrate 1, and is provided with a spring 13 provided between the distal end side flange portion 12 </ b> A and the substrate 1.
The position where the rear end side flange portion 12B normally abuts on the back surface of the substrate 1, that is, the chuck 2 toward the front side of the substrate 1
And the position where the amount of protrusion of the intake cylinder 12 is the largest.

At the lower side of each of the chucks 2, 2,..., A supporting member 14 projects to the front side of the substrate 1 so as to be detachable with a space slightly larger than the outer radius of the body 10A of the molded article 10. Installed. The support member 14 has a gutter-shaped support portion 14A, and is formed of a heat insulating material having a low thermal conductivity such as a foamed resin. The inner peripheral radius of curvature of the gutter-shaped support portion 14A is
The base portion 14B, which is set to a value slightly larger than the outer radius of curvature of A and is connected to the gutter-shaped support portion 14A,
5 is fixed to the substrate 1 by bolts 16.
The substrate 1 is attached to the tip of the unloader.

The removal of a molded product performed by the molded product removal head according to the present invention will be described. (A). As shown in FIG. 5, the take-out head is brought close to the molded products 10, 10...
The gutter-shaped support portion 14A of the support member 14 is applied to the lower half of the body portion 10A of 10 ... and the chucks 2, 2 ... are brought into contact with the bottom portion 10B of the molded products 10, 10 .... (B). By the suction of the suction means 4, the inside of the chucks 2, 2,... Is made negative pressure, and the bottom 10B of the molded articles 10, 10,. (C). The removal head 5 is moved in a direction away from the mold 9 by the operation of the removal machine 5, and the molded products 10 are pulled out of the mold 9. That is, the molded articles 10, 10,... Are released. (D). The bottoms 10B of the molded articles 10, 10 are adsorbed by the chucks 2, 2 and the lower half of the body 10A is supported by the gutter-shaped support portion 14A of the support member 14, that is, the chucks 2, 2. ... And the support member 14 together with the molded product 10,
While holding 10..., The take-out head is moved to the inlet of the cooling means (not shown) installed outside the mold 9 by the operation of the take-out machine 5, where the suction of the suction means 4 is released. .. Are transferred to the inlet of the cooling means, and while the transferred molded articles 10, 10. The cooling is performed at a high cooling rate by the cooling device.

According to the first aspect of the present invention, the molded articles 10, 10 immediately after molding, which are held in the mold 9 that has been opened.
The support member 1 is formed by adsorbing the bottom portion 10A of the molded product 10, 2 by using the chucks 2, and by forming the lower half of the body portion 10B of the molded product 10, 10 with a heat insulating material having a low thermal conductivity.
In the process from release from the gutter-shaped support member 14 due to the heat retaining effect to transfer at the inlet of the cooling means, the molded products 10 and
10 are prevented from lowering in temperature, so that the cooling water passages 7 function as water jackets.
(See FIG. 8) becomes unnecessary. Naturally, it is also possible to omit the constant circulation of the cooling water, so that downsizing and weight reduction can be achieved.

In practice, the weight per one chuck 2 is reduced to about 0.3 kg. Therefore, in the case of a take-out head for a molded product including the 16 chucks 2, 2,... And the support member 14 as in the embodiment, the total weight is about 4.8K.
g. For this reason, high-speed movement by the unloader 5 becomes possible, and the unloading time of the molded articles 10, 10,... Can be reduced to about 2 seconds at the highest speed. As a result, the molding cycle time by the molding machine can be shortened, and the molding efficiency can be improved. In addition, since the inertia is reduced by reducing the weight, it is easy to stop quickly and appropriately at a predetermined position, and to properly remove the molded articles 10, 10. Can also.

The temperature of the temperature (80 ° C.) at the time of taking out from the mold 9 is achieved by cooperation between the support member 14 and the high-speed movement from the mold 9 to the inlet of the cooling means. .. Can be moved and transferred to the cooling means in the next step in a near high temperature state. As a result, in the cooling means in the next step, the cooling rate is increased by a dedicated cooler provided in the hatched area x1 which is higher than the limit cooling rate in FIG.
0 can easily be reduced to around 40 ° C. within about 20 seconds, and the occurrence of “whitening” can be reliably prevented.

Further, the cooling water supply hose 8A and the cooling water discharge hose 8B for circulating the cooling water shown in FIG. 8 or the turning means for inversion or inversion return not shown in FIG. This further contributes to a reduction in weight that can simplify the structure.

In the above embodiment, the molded article 10,
In the description, the lower half of the body 10B of 10 is supported by the gutter-shaped support portion 14A of the support member 14.
As shown in FIG. 6, a configuration may be adopted in which a cylindrical support portion 14B of the support member 14 surrounds and supports the entire circumference of the body portion 10B. That is, by supporting at least the lower half of the body 10B of the molded articles 10, 10,... By the support of the support member 14, a heat retaining effect can be obtained.

[0019]

As described above, according to the first aspect of the present invention, the bottom of the molded product immediately after molding is adsorbed by the chuck, and the body of the molded product is formed of the heat insulating material having a small thermal conductivity. Since it can be released by being supported by the supporting member and released, and moved to the cooling means in the next step while being kept warm by the supporting member, the cooling water passage functioning as a water jacket becomes unnecessary. Can be omitted, so that downsizing, weight reduction, and simplification of the structure can be achieved. For this reason, high-speed movement by the unloader becomes possible, and the unloading time of the molded product can be greatly reduced. As a result, the molding cycle time by the molding machine can be shortened, and the molding efficiency can be improved. In addition, since the inertia is reduced by reducing the weight, it is easy to quickly and appropriately stop at a predetermined position, and it is possible to avoid a decrease in the precision of taking out the molded product, and to prevent the molded product from being moved by the support member. It is possible to move the molded product to the cooling means in the next process and transfer it in a high temperature state close to the temperature at the time of mold release by cooperation with high speed movement and the high temperature movement of the next process. In the cooling means, it is easy to raise the cooling rate to a value equal to or higher than the limit cooling rate by a dedicated cooling machine provided, and to lower the molded article to a temperature near a predetermined temperature within a predetermined time. Occurrence can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of the invention described in claim 1;

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a bottom view of FIG. 1;

FIG. 4 is an enlarged sectional view showing an attached state of a chuck and a support member.

FIG. 5 is a diagram corresponding to FIG. 2, showing a state immediately before release.

FIG. 6 is an enlarged sectional view of another embodiment of the support member.

FIG. 7 is a table showing cooling characteristics of a molded product.

FIG. 8 is a schematic configuration diagram of a conventional molded product take-out head.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 substrate 2 chuck 4 suction means 10 preform molded product (molded product) 10A bottom of molded product 10B trunk of molded product 14 support member

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 49 / 06,49 / 28-49/42 B29B 11/08 B29L 22:00

Claims (1)

(57) [Claims] 1. A substrate, a chuck protrudingly mounted on the front side of the substrate and connected to an air intake means for detachably adsorbing a bottom of a preform molded product, and a front side of the substrate near the chuck. And a support member for supporting the body of the preform molded product, the support member being protruded from the plastic bottle, and the support member is formed of a heat insulating material having a low thermal conductivity. Removal head for reformed products.