Secondary injection molding machine for hollow molded products

This invention relates to a secondary molding machine capable of injection molding a handle, a base cup, or the like on a body portion, a bottom portion or the like of a thin-wall hollow container made of synthetic resin. The machine includes a rotational member provided movably up and down on a column on a machine bed, an insert mechanism including a lateral molded-product holding device mounted on the rotational member, a clamping mechanism for connecting an upper clamping plate, which is moved up and down for opening and closing the mold cavities to the rotational member, a secondary mold that is opened and closed up and down having the same first cavity as a hollow molded product and a secondary molding cavity. An air blowing device is connected to a blow core.

FIELD OF THE ART 
This invention relates to a molding machine which can secondarily 
injection-mold a handle, a base cup and the like on a synthetic resin 
hollow product such as a blow-molded bottle. 
BACKGROUND 
An injection blow molding machine capable of primarily injection molding a 
base cup on a bottom of a thin-wall synthetic resin container oriented 
blow molded has been already known from Japanese patent application 
Laid-Open Publication No. 58-194520. 
The above molding machine is designed so that a hollow molded product such 
as a bottle oriented blow molded is moved, without being removed from a 
transfer plate, to a secondary molding mold provided adjacent to a blow 
molding mold, and an internal pressure is applied under the attitude of 
the product oriented blow molded to inject a base cup. 
A secondary molding of a handle to a hollow molded product oriented blow 
molded is disclosed in Japanese patent application Laid-Open Publication 
No. 62-181130. Also in this molding method, an internal pressure is 
applied to a hollow molded product to injection mold a handle on a 
thin-wall body portion but this application discloses no apparatus 
required for molding. 
It is convenient to carry out the secondary molding of a handle or the like 
while holding a hollow molded product on the side of a transfer plate as 
in the above-described molding machine in terms of supplying a hollow 
molded product to a secondary molding mold. A relative position between a 
hollow molded product as a member to be molded and a secondary molding 
mold can be easily coincided. In this case, however, a series of 
operations comprising injection molding of a parison, orientation blow 
molding of a hollow molded product and secondary molding are continuously 
carried out. Therefore, this system can be employed for a molding method 
generally called a hot parison system but cannot be employed for a cold 
parison system in which a molded parison is orientation blow molded later 
by other apparatus. 
Problems encountered in the case where a handle or the like is injection 
molded to a hollow molded product after removal from an orientation blow 
molding machine lie an insert of a hollow molded product into a mold, and 
a connection between an air blowing device for applying an internal 
pressure and a hollow molded product. It is therefore desirable to develop 
a secondary injection molding machine which is easy for insertion, which 
can positively provide a connection between a hollow molded product within 
the mold and a blow core, and which can supply an internal pressure enough 
to withstand an injection pressure into a hollow molded product. 
DISCLOSURE OF THE INVENTION 
Accordingly, this invention has been achieved in view of the aforementioned 
circumstances. An object of this invention is to provide a secondary 
injection molding machine for inserting a hollow molded product such as a 
bottle made of synthetic resin into a secondary molding mold to 
secondarily injection mold a handle on a body portion or a base cup or the 
like on a bottom portion thereof, in which the insertion of a hollow 
molded product into a secondary molding mold can be smoothly done and 
pressing of a hollow molded product within the mold by air pressure can be 
positively carried out. 
For achieving the aforesaid object, this invention provides a secondary 
injection molding machine comprising a rotational member provided movably 
up and down on a column on the machine bed, an insert mechanism comprising 
a lateral molded-product holding device mounted on the rotational member, 
a vertical clamping mechanism positioned adjacent to the insert mechanism 
and having an upper clamping plate which is vertically moved for opening 
and closing a mold connected to the rotational member, a secondary molding 
mold mounted on the clamping mechanism so that the secondary molding mold 
is opened and closed up and down, an injection device on the machine bed 
disposed horizontally with respect to :he clamping mechanism, and an air 
blowing device positioned on the side of the column and connected to the 
blow core at a descended position. 
The above-described secondary molding mold has the same cavity as a 
premolded hollow molded product and a secondary molding cavity, and the 
above-described molded-product holding device bas a chuck holding an 
opening and a blow core having a fore end which extends through the chuck 
positioned within the opening, whereby a mouth portion of a hollow molded 
product is held and fixed, and an internal pressure of air pressure is 
applied thereto to render possible injection molding of secondarily molded 
parts such as a handle and the like in position as required. 
With the above-described structure, a hollow molded product is laterally 
held by the holding device of the insert mechanism, at the position 
opposite to the clamping mechanism. The insert mechanism rotatably moves a 
hollow molded product as well as a holding device to the secondary molding 
mold in an opened state. When the insert mechanism stops, closing starts 
and the upper clamping plate moves down. Since the upper clamping plate 
and the rotational member of the insert mechanism are connected, the 
insert mechanism is moved down simultaneously and insertion of a hollow 
molded product into the secondary molding mold is carried out. 
When clamping is completed, the air blowing device is connected to the blow 
core through which the chuck of the holding device extends, and air is 
pressed into the hollow molded product to apply an internal pressure 
thereto. Thereafter, a molten resin is injected and filled in the 
secondary molding cavity within the mold to mold a secondary molded part 
on the body portion or bottom portion of the hollow molded product. 
Accordingly, a hollow molded product is not deformed due to an injection 
pressure. In closing, a hollow molded product is also moved up and down 
owing to upward and downward motion resulting from the connection between 
the insert mechanism and the upper clamping plate to effect insertion of 
release, whereby even at the time of transfer caused by rotation, it is 
possible to accurately perform a positioning of a hollow molded product 
with respect to a mold.

BEST MODE FOR CARRYING OUT THE INVENTION 
The molding machine shown in the drawings is a molding machine for 
secondarily molding a handle on a body portion of a thin-wall bottle 
orientation-blow molded. Adjacent to a machine bed 1, a column 3 of an 
insert mechanism 2 and a vertical clamping mechanism 4 are provided. 
The insert mechanism 2 is composed of a rotational member 5 provided on the 
column 3 rotatably and movable up and down by use of a bearing, a spline 
shaft or the like and a lateral holding device 6 mounted on the underside 
of the rotational member 5. 
The holding device 6, details of which are shown in FIGS. 3 and 4, is 
composed of a holding body 7 affixed to a lower edge 5a of the rotational 
member 5, a blow core 8 extended into the holding body 7, a chuck 9 that 
may be opened up and down provided in the periphery of the fore end of the 
blow core 8, and an opening and closing cylinder 11 of the chuck mounted 
on a holder 10. A spring 8a is inserted between the chuck 9 and a core 
shoulder. 
The clamping mechanism 4 is of the vertical type in which an upper clamping 
plate 12 is positioned on the machine bed, and a lower clamping plate and 
a clamping cylinder are positioned within the machine bed though not 
shown, the upper clamping plate 12 being moved up and down together with a 
tie bar to effect opening and closing. 
The upper clamping plate 12 of the clamping mechanism 4 and the rotational 
member 5 of the insert mechanism 2 are connected with each other so that 
the insert mechanism 2 is moved up and down together with the upper 
clamping plate 12. 
On the upper clamping plate 12 and a lower clamping plate (not shown), a 
divisional secondary molding mold 13 shown in FIG. 5 and thereafter is 
mounted. This mold is provided with a cavity 15 having the same shape as a 
premolded bottle 14 made of synthetic resin and a secondary molding cavity 
16 for molding a handle, and further provided with a fastening portion 17 
of the chuck 9. 
An air blowing device indicated at 18 is mounted on the machine bed on the 
side of the column 3. When the holding device 6 is moved down and a plug 
19 provided directed at the clamping mechanism is pushed out by a cylinder 
20, the air blowing device 18 comes into contact with a rear end 8b of the 
blow core 8 and urges the blow core 8 against the spring 8a. 
The operation of the machine will be described hereinafter. 
An opening of the bottle 14 is fitted into the fore end of the blow core 8, 
as shown in FIG. 3, after which the chuck 9 is closed to hold the mouth 
portion of the bottle to hold the bottle 14 horizontally as shown in FIG. 
4. 
Then, the insert mechanism 2 is rotated counter-clockwise through 180 
degrees by the rotational member 5 to move the bottle 14 to the opened 
secondary molding mold 13 (see FIG. 5). After stop and when the clamping 
mechanism 4 is actuated to move the upper clamping plate 12 downwardly and 
to shift the mode to the closing step, the insert mechanism 2 is also 
moved down and the bottle 14 positioned in the mold is also moved 
downward. Closing as shown in FIG. 6 is carried out. 
When clamping further takes place, the chuck portion is held down by the 
fastening portion 17 so as to withstand internal pressure. Thereafter, the 
plug 19 of the air blowing device 18 is placed in pressure contact with 
the rear end of the blow core 8, and air pressure of approximately 30 
kg/cm.sup.2 is applied into the bottle through the blow core 8. After 
pressing, a secondary molding material is injected into the secondary 
molding mold 13 from the injection device 21 on the machine bed 1 disposed 
horizontally with respect to the clamping mechanism and a handle 23 
integral with a band 22 surrounding the secondary molding cavity 16 is 
produced by the resin filled into the secondary molding cavity 16. 
After molding, the upper clamping plate 12 is moved upward to effect 
opening, and at the same time, a projecting device 24 provided over both 
the mold and the holding device is moved upward whereby the holding body 7 
and the bottle 14 are somewhat forced up, and releasing from a lower mold 
is effected. The bottle 14 having been subjected to secondary molding 
positioned in the mold is again returned to the insert position by the 180 
degrees rotation of the insert mechanism. A new bottle is inserted into 
the mold. 
INDUSTRIAL APPLICABILITY 
A secondary molding machine of this invention is designed so that a mouth 
portion of a hollow molded product is held by a blow core and a chuck, and 
after clamping, internal pressure can be applied while holding the mouth 
portion. Therefore, the hollow molded product is not deformed due to an 
injection pressure, and a handle or the like can be very easily subjected 
to secondary molding. In addition, positioning of a hollow molded product 
with respect to a mold can be accurately performed by upward and downward 
motion resulting from a connection between an insert mechanism and an 
upper clamping plate. The aforesaid effects are great and very useful in 
industry, and the present machine is extensively utilized.