JPH06315973A - Molding apparatus - Google Patents

Abstract

PURPOSE:To prevent a change in the temp. distribution of a preform by uniformizing the time before the close contact of the preform and a temp. adjusting means is released by a simple structure. CONSTITUTION:A molding apparatus is equipped with a preform P subjected to a temp. conditioning process and a temp. adjusting means 46 capable of coming into contact with the inner wall surface of the preform P and the temp. adjusting means 46 is equipped with a structure 46 increasing separating drive force at the initial stage when the means 46 is separated from the inner wall surface of the preform P. Since the time before the close contact of the preform and the temp. adjusting means is released is uniformized by the increase of the drive force, the overheating or supercooling of the preform is prevented and proper wall thickness distribution can be set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus, and more particularly, to a drive structure of a temperature adjusting means capable of contacting an inner wall surface of a preform during temperature control of the preform.

[0002]

2. Description of the Related Art Generally, a thin-walled container made of synthetic resin called a biaxially stretch blow molded container (hereinafter referred to as a molded product).
Can be obtained, for example, by locating a preform obtained by injection molding in the cavity of a blow mold, stretching it in the axial direction of the container, and expanding it in the direction perpendicular to the axial direction by the pressure of the gas blown inside. .

As a molding device for such a molded product, there is, for example, a structure called a one-stage system or a hot parison system. It is well known that the steps carried out by this system are injection molding in the first step, heating the preform in the second step to adjust the temperature, and the third step. In step 4, stretch blow is performed, and in the fourth step, the molded product is taken out, and these steps are continuously performed.

By the way, the temperature adjustment carried out in the second step is carried out in order to set a suitable stretching temperature for obtaining the wall thickness distribution in the final molded product. This is because the final molded product has internal pressure resistance and impact resistance, and further has gripping strength when gripped. The structure for carrying out the second step is, for example, the structure described in Japanese Patent Laid-Open No. 3-290225.

According to the above-mentioned publication, the conveyed preform is inserted into the temperature control pot, and the fluid, in this case, the heating surface having the temperature distribution in the vertical axis direction in the temperature control pot is used. It has a structure in which the preform is brought into contact with the air blow pressure to adjust the temperature by heat conduction. Such blowing of air is called pre-blowing because it is performed before stretching and blowing.

Further, in the structure described in this publication, the portion immediately below the lip portion, which is difficult to be stretched due to the earliest contact with the blow cavity surface during stretch blow molding,
A structure is provided for heating for the purpose of ensuring a predetermined stretch ratio and adjusting the temperature of the inner layer of the preform. Specifically, a temperature adjusting means having a core for blowing air (hereinafter, referred to as a preliminary blow core) and a heating piece projecting directly below the lip portion from the inside is provided, and the heating piece is provided with the above-mentioned lip portion. It faces the inner wall surface directly below. The preliminary blow is not limited to the one-stage method described above, but is a cold parison method, that is, a so-called two-stage method, in which the preform after the injection molding process is stretch blow molded in a stage different from the injection molding section. Can also be adopted in.

Further, as the temperature adjusting structure in the second step, there is a structure which does not perform pre-blow. That is, although not shown, the structure in this case has a temperature adjusting means provided with a core capable of contacting the inner wall of the preform, particularly the inner wall of the body except for the portion immediately below the lip where it is necessary to keep the amount of heat retained high. The core has, as an example, a structure in which the inner layer of the preform is temperature-controlled to a temperature lower than that of the outer layer of the preform heated by the heating pot. In this case, the outer wall surface of the preform and the inner peripheral surface of the temperature control pot are not in contact with each other, and the preform is heated by so-called radiant heat from the temperature control pot.

[0008]

By the way, regardless of the one-stage or two-stage method, the preform obtained by injection molding has a second shape after the injection molding with the lip portion held by the lip cavity mold. The temperature is transferred to a station that executes a temperature control process.

In the temperature adjusting step, for example, in terms of a structure for performing pre-blowing, which is one of the structures for executing the step, the pre-blowing core of the temperature adjusting means that can be inserted and removed into the inside of the preform is The lip portion is sandwiched together with the lip cavity mold by inserting the seal portion provided at the tip of the preliminary blow core into the lip portion of the preform. Therefore, when the preliminary blow is performed, the seal portion is in close contact with the lip portion to prevent the leakage of blow air from the inside.

On the other hand, in the structure for performing the temperature adjusting step, which is another example of the structure for not performing the pre-blowing, the core forming the temperature adjusting means is inserted into the inside of the preform and comes into contact with the inner wall surface of the body. In this state, the gap between the preform and the temperature control pot is optimized so that the radiant heat is evenly supplied.

However, the inner wall surface of the lip portion or the inner wall portion of the body portion of the preform is likely to undergo thermal contraction by being absorbed by the preliminary blow core or the temperature control core of the temperature adjusting means. For this reason, the preform is more likely to adhere to the preliminary blow core or the temperature control core at a pressure higher than that at the time of fitting. Therefore, when the preliminary blow core or the temperature control core is detached after the temperature control, the adhesive force acts as a resistance force, and the core may not be smoothly removed. In particular, from the viewpoint of production efficiency, when a large number of molded products are obtained by molding a large number of products at one time, the adhesive force at each core is not always uniform and the resistance force increases. Tends to be easy. Therefore, after the end of the temperature control step, the driving unit of the core needs a driving force that resists the resistance force due to the adhesive force, and as a result, a large driving force is required. The time when such a large driving force is required is in the case of the structure using the pre-blow until the separation of the seal part of the pre-blow core from the lip part. Since the outer shape of the temperature control core is often tapered, a gap is formed between the outer wall surface of the temperature control core and the inner wall surface of the preform until air enters between them.

On the other hand, as a drive source for inserting and removing the core, a hydraulic cylinder or an air cylinder using a compressive fluid is used. However, in the case of a hydraulic cylinder, there are problems that the device is expensive and that the installation structure such as the arrangement of piping is complicated and tends to be large. Therefore, an air cylinder is often used instead of the hydraulic cylinder. However, in order to set a large driving force when the air cylinder is disengaged, the diameter of the cylinder must be increased. However, simply providing such a structure only for the above-mentioned time is troublesome in air intake / exhaust control, and further, waste is likely to occur in terms of air use efficiency.

Moreover, when an air cylinder is used,
There is a delay time until the driving force is increased to a pressure at which it can be obtained. In particular, this delay time tends to be long when a large driving force is required. In addition to the occurrence of such a delay time, it cannot be said that the adhesion state to the core is always the same for each preform within the number of simultaneous moldings. When the core is to be detached from the preform due to factors such as the adhesion state may not be the same for each of the blocks, the core detachment operation may start while the drive source is boosting the pressure to the specified pressure. Or, conversely, the core may not start the detaching operation even if the pressure is increased to a predetermined pressure.

For this reason, the time until the close contact between the preform and the core is released is not always uniform in all the preforms. Therefore, if the timing at which the close contact between the preform and the core is released is different, the temperature control time for the preform will also vary, and the preform will be overheated or overcooled.
Therefore, the suitable temperature for stretching the preform changes,
The wall thickness distribution of the molded product after blow molding deviates from the predetermined condition.

In view of the above-mentioned problems in the conventional molding apparatus, the object of the present invention is to make uniform the time for releasing the close contact between the preform and the temperature adjusting means with a simple structure and to keep the temperature of the preform. It is an object of the present invention to provide a molding apparatus capable of preventing a change in distribution.

[0016]

To achieve this object, the invention according to claim 1 is arranged in a temperature control pot before stretch-blow molding the preform, and the temperature of the preform in the axial direction is set. In a molding apparatus having a structure for adjusting the temperature of the distribution to an appropriate temperature for stretching, it is provided so as to be insertable and removable with respect to the preform arranged in the temperature adjustment pot, and when inserted,
The driving means is capable of contacting the inner wall of the preform and comprises means for adjusting the temperature of the inner layer of the preform, and driving means for respectively driving the temperature adjusting means in the inserting / removing direction, wherein the driving means is At least at the time of initial driving for driving the temperature adjusting means to separate, and at least during the initial driving to separate from the inner wall of the preform, the temperature adjusting means is provided with a structure for increasing the separation driving force. .

According to a second aspect of the present invention, in the first aspect, the temperature adjusting means is provided so that it can be inserted into and removed from the preform, and contacts the inner wall of the lip portion of the preform during insertion. A pre-blowing is performed with a pressure that brings the preform into contact with the temperature control pot in a state where the seal portion and a heating piece that heats just under the lip portion are provided, and the seal portion is in contact with the inner wall of the lip portion. It is characterized by having a structure.

According to a third aspect of the present invention, in the first aspect, the temperature adjusting means is provided so that it can be inserted into and removed from the preform, and upon insertion, it comes into close contact with the inner wall of the body of the preform. It is characterized by having a core and having a structure for setting a gap between the temperature control pot and the preform.

According to a fourth aspect of the present invention, in one of the first to third aspects, the driving means inserts and removes the temperature adjusting means with respect to the preform arranged in the temperature adjusting pot. A main drive means for driving, and at least
Auxiliary driving means for increasing the detaching driving force of the temperature adjusting means when the temperature adjusting means is detached from the inner wall of the preform at the time of initial driving for detaching and driving the temperature adjusting means by the main driving means. And are characterized by having.

According to a fifth aspect of the present invention, in the molding apparatus according to the fourth aspect, the auxiliary driving means is elastically deformed when the temperature adjusting means is driven to be inserted, and the elastic deformation force is released at the initial stage of the detaching driving. And a return spring for increasing the detachment driving force of the temperature adjusting means.

According to a sixth aspect of the present invention, in the molding apparatus according to the fourth aspect, the main drive means reciprocally drives the plate to which the auxiliary drive means is fixed,
The auxiliary drive means is such that the temperature adjusting means reciprocates with a short stroke, and at least during the initial drive when the temperature adjusting means is driven to be separated, the main drive means and the auxiliary drive means are simultaneously driven. It has a feature.

According to a seventh aspect of the present invention, in the molding apparatus according to the fourth aspect, the main drive means and the auxiliary drive means are both air cylinders, and a single rod for inserting and removing the temperature adjusting means is provided. A cylinder having a plurality of isolated spaces in which the rod moves, and a plurality of pistons fixed to the rod at positions arranged in the respective spaces, and at least the temperature adjusting means is detached. It is characterized in that air for simultaneously driving a plurality of pistons is introduced into the plurality of spaces at the time of initial driving.

[0023]

According to the present invention, the temperature adjusting means that can be inserted into and removed from the preform is increased in removal driving force at least at the time of the initial driving for driving the removal from the inside of the preform. Therefore, even if the inner wall surface of the preform firmly adheres to the temperature adjusting means due to heat shrinkage, and even if the extraction resistance of the temperature adjusting means increases, the temperature adjusting means and the preform are brought into close contact with each other in a short time. The temperature adjusting means can be removed by releasing. For this reason, the close contact state is released in a time when the temperature adjusting means and the preform are extremely uniformized, so that the temperature distribution of the preform is prevented from collapsing and the wall thickness distribution of the molded product varies. Can be prevented.

Further, according to the present invention, the main driving means for driving the temperature adjusting means in the inserting / removing direction and at least the initial driving for driving the temperature adjusting means by the main driving means to separate / drive,
And auxiliary driving means for increasing the detachment driving force of the temperature adjusting means. Therefore, without changing the temperature adjusting means, it is possible to release the close contact state between the temperature adjusting means and the preform within a uniformed time simply by attaching the auxiliary driving means.

[0025]

The present invention will be described in detail below with reference to the illustrated embodiments.

FIG. 1 is a plan view showing a machine base 20 of a blow molding apparatus 10 as an example of the molding apparatus according to the present invention.

A turntable 22 is provided on the machine base 20.

The turntable 22 is provided so as to be intermittently rotatable with respect to the machine base 20 in the direction of the arrow in the figure, and stations for performing each molding process are installed along the direction of rotation. The present embodiment is intended for the one-stage system, and therefore, in the circumferential direction of the turntable 22, an injection molding station 12 that performs injection molding of a preform,
A temperature control station 14 for adjusting the temperature of the preform to a temperature suitable for blow molding, a stretch blow molding station 16 for performing blow molding of the preform to form a molded article having a predetermined shape, and molding by opening the lip mold. An eject station 18 for taking out products is installed.

A rotary table 22 corresponding to each of the above stations
Each of the four lip type transfer plates 24 is provided in the. A lip type support plate 26 is attached to each lip type transfer plate 24, and a number of lip cavity types 28 corresponding to the number of simultaneous moldings are attached to the lip type support plate 26. Therefore, the neck portion of the preform is held by these lip cavity molds 28. Therefore, the lip mold support plate 26 is composed of divided plates to which a number of lip cavity molds 28 corresponding to the number of simultaneous moldings can be attached, and the lip cavity molds 28 are attached to the respective divided plates as split molds. There is. The lip type support plate 26 is normally provided with a habit of moving in the closing direction, and can be opened and closed by an opening / closing means (not shown). When closed, the lip cavity type 28 allows the neck portion of the preform to be opened. Can be pinched.

On the other hand, the temperature adjusting station 14 is provided with an elevating / lowering drive section of temperature adjusting means having the structure shown in FIG. It should be noted that the temperature adjusting means shown in FIG. 2 is intended for a structure including a preliminary blow core and a heating piece so that preliminary blow can be performed.

That is, the elevating / lowering drive unit 30 constitutes a drive unit for inserting / removing the preliminary blow core into / from the preform P, and the drive unit is composed of a main drive unit and an auxiliary drive unit.

The main drive unit includes a vertical guide unit for the auxiliary blow core and a drive source. The elevating guide portion of the preliminary blow core is composed of a plurality of guide shafts 32, and the guide shafts 32 sandwich the base plate 34 to rotate the rotary plate 2
The lower end is fixed to a base 36 that is arranged so as to face 2. A cylinder base 38 is fixed to the upper end of the guide shaft 32, and the cylinder base 4 is fixed to the cylinder base 38.
The air cylinder 40, which is a main part of the main drive unit, is fixed in a state in which 0A is projected downward.

A movable plate 44 integrated with the preliminary blow core fixing plate 42 is provided at the tip of the cylinder shaft 40A.
Is attached. A number of preliminary blow cores 46 corresponding to the number of simultaneous moldings are attached to the preliminary blow core fixing plate 42, and the heating piece is located inside the seal portion 46A located at the tip of the preliminary blow core 46. Therefore, the cylinder shaft 40 by the air cylinder 40
By moving the preliminary blow core fixing plate 42 in conjunction with the raising / lowering operation of A, the seal portion 46A of the preliminary blow core 46 can be inserted into and removed from the lip portion of the preform P, and the tip of the preliminary blow core 46 is also removed. Air is blown from the preform for pre-blowing the preform.

On the other hand, on the guide shaft 32, a return spring 48 which is an auxiliary drive portion is arranged between the base 36 and the preliminary blow core fixing plate 42. This return spring 48
When the preliminary blow core 46 is separated from the lip portion of the preform P, the increasing drive force of the preliminary blow core 46 is increased at least at the initial stage of driving the preliminary blow core 46 to separate. For this reason, the return spring 48 is elastically deformed when the preliminary blow core 46 is inserted into the preform P, and the elastic deformation force is released in the initial stage of the detachment drive to increase the detachment drive force. There is. The number of turns and the spring length of the return spring 48 are set in consideration of the fact that the elastic deformation force may be applied in the initial stage of the detachment drive of the preliminary blow core 46.

Such an increase in driving force overcomes the pull-out resistance due to the adhesive force when the lip portion of the preform P is in close contact with the seal portion 46A of the preliminary blow core 46 due to thermal contraction. The preliminary blow core 46 is removed from the lip portion in a short time.
Therefore, the driving force at the initial stage of the removal of the preliminary blow core 46 is usually the air cylinder 40 required to separate the preliminary blow core 46 from the lip portion of the preform P when only the weight of the preliminary blow core 46 is targeted. Is set to a value obtained by adding the stored elastic force of the return spring 48 elastically deformed in addition to the driving force of FIG. 3 shows the relationship between the detachment driving force to which the elastic force of the return spring 48 is applied and the normally set detachment driving force. The state indicated by the symbol A (two-dot chain line) is the present embodiment. Is the drive force for separation. In FIG. 3, the driving force indicated by the symbol S is due to the return spring 48, and the largest restoring force is set at the initial stage when the preliminary blow core 46 starts the detachment drive from the lip portion of the preform P.

Next, the operation will be described.

At the temperature control station 14, the state where the air cylinder 40 is raised is set as the initial state. Therefore,
As shown in FIG. 2, the preliminary blow core fixing plate 42 and the movable plate 44 driven by the air cylinder 40 stand by at the position where the preliminary blow core 46 is separated from the lip type support plate 26.

On the other hand, when the lip type support plate 26 reaches the temperature control station 14 by the rotation of the rotary plate 22, the temperature control step is carried out. In this process, the air cylinder 4
The cylinder shaft 40A of 0 descends, and in conjunction with this, the preliminary blow core fixing plate 42 and the movable plate 44 descend. At this time, as shown in FIG. 4, the return spring 48 elastically deforms to store an elastic force. Therefore, as shown in FIG. 5, the seal portion 46 </ b> A of the preliminary blow core 46 has the preform P held by the lip type support plate 26.
Is inserted into the lip portion P1 and the inner wall surface of the lip portion P1 is brought into close contact with the outer wall surface of the seal portion 46A, whereby the blow air from the inside of the preform P is sealed.

When the temperature adjusting process is completed, the air cylinder 40 returns to the initial state. At this time, the accumulated elastic force of the return spring 48 is released in addition to the ascending return driving force of the air cylinder 40, so that it is larger than the normally set driving force for separation as described in FIG. The preliminary blow core 46 is driven by the driving force so that the lip portion P
Extracted from 1. Therefore, the speed at which the seal portion 46A of the preliminary blow core 46 separates from the lip portion P1 of the preform P becomes faster than when the driving force of only the air cylinder 40 is used.

According to the present embodiment, the time required for releasing the close contact between the lip portion P1 and the seal portion 46A of the preliminary blow core 46 and releasing the lip portion P1 and the seal portion 46A of the preliminary blow core 46 is shortened by the simple constitution of simply adding the return spring 48 to the existing constitution. It becomes possible to do.

On the other hand, FIG. 6 shows another embodiment,
This embodiment is characterized in that the structure of the auxiliary drive unit is constituted by an auxiliary cylinder 50 that operates in the same direction as the air cylinder 40 that forms the main drive unit at the initial stage of starting the separation of the preliminary blow core 46.

That is, in this embodiment, the preliminary blow core fixing plate 42 is attached to the cylinder shaft 50A of the auxiliary cylinder 50. And this auxiliary cylinder 50 is
At least, the preliminary blow core 46 is driven together with the air cylinder 40 in the initial stage of the detachment drive. Therefore, the auxiliary cylinder 50 is connected to the cylinder shaft 40A of the air cylinder 40.
It is attached to a movable plate 44 fixed to the air cylinder 40 so that it can be interlocked with the air cylinder 40.

Therefore, the auxiliary cylinder 50 increases the detaching driving force in addition to the driving force of the air cylinder 40 at least at the initial stage when the preliminary blow core 46 is detaching driven, as in the embodiment shown in FIG. be able to. As a result, the driving force at the initial stage of the detachment driving of the preliminary blow core 46 is obtained by the sum of the driving force of the air cylinder 40 and the driving force of the auxiliary cylinder 50, and therefore the preliminary blow core 4
The time until the close contact between the seal portion 46A of No. 6 and the lip portion P1 of the preform P is released is shortened.

FIG. 7 shows another embodiment,
In this embodiment, the preliminary blow core 46 is replaced with the preform P.
The driving force for separating from the lip portion can be set by the structure of the air cylinder itself. The air cylinder 40 is premised on that the movable plate 44 attached to the cylinder shaft 40A has the structure shown in FIG.

That is, inside the air cylinder 40,
Multiple spaces, in this case the first space 40B separated into two chambers
And 2nd space 40C is comprised, and piston 52,54 is provided in each space. In addition, of these pistons, the piston 5 located in the first space
2 is an air cylinder 4 for inserting and removing the preliminary blow core 46
It is integrated with the single cylinder shaft 40A on the 0 side.
The piston 54 located in the second space 40C has a flange portion 40A whose upper surface is integrated with the cylinder shaft 40A.
1 is abutted against. Therefore, the cylinder shaft 40A
Can be moved up and down in the drawing in accordance with the movement of the piston 54 in the second space by the air supply / discharge control in the first space 40B. The piston 54 on the side of the second space 40C is seated on the bottom surface of the second space 40C in normal times, that is, when it is not time for the preliminary blow core 46 to separate from the lip portion P1 of the preform P. The combination with the flange 40A1 is to drive the cylinder shaft 40A only when the cylinder shaft 40A is moved upward only in the initial stage when the movement is started.

On the other hand, the first space 40B is a space for setting a driving force for moving the movable plate 44 up and down. Therefore, the air supply / discharge port 40B is provided in the first space 40B.
1 and 40B2 are formed, and air passages 58 and 6 connected to an electromagnetic directional switching valve 56 are formed in the supply / discharge ports.
0s are connected.

The second space 40C is a space into which the air for raising the piston 54 is introduced only when the preliminary blow core 46 separates from the lip portion of the preform P only during the initial drive. Therefore, in the second space 40C, a supply / discharge port 40C1 that is normally set in an exhaust state is formed, and in the supply / discharge port 40C1, an air passage connected to the electromagnetic direction switching valve 62 is formed. 64 are connected.

The direction switching valve 56 switches the air introduction direction according to the insertion / removal direction of the preliminary blow core 46. Further, the direction switching valve 62 introduces air only during the initial drive when the preliminary blow core 46 is separated from the lip portion of the preform P, so that the piston 54
Is to raise. The air supplied to the direction switching valves 56 and 62 is supplied from the same pump 66.

Therefore, the first and second spaces 40B, 4
At 0C, when the cylinder shaft 40A is raised and the seal portion of the preliminary blow core 46 is pulled out from the lip portion of the preform P, the piston in the second space 40C is different from the pressure receiving area of the piston 48 in the first space 40B. The pressure receiving area added with the pressure receiving area of 54 is set. As a result, when air is introduced into the second space 40C, the pressure for raising the cylinder shaft 40A is doubled, so that the moving speed of the cylinder shaft 40A is accelerated.

In this embodiment, the spare blow core 46 is used.
When inserting into the lip portion of the preform P, the cylinder shaft 40A descends. Therefore, in the first space 40B, the piston 52 is
The moving direction of is set. On the other hand, the second space 40
At C, the directional control valve 62 is not in the operating position, which causes the piston 54 to remain seated.

On the other hand, when the cylinder shaft 40A is lowered, the preliminary blow core 46 is inserted into the lip portion, and when the temperature adjusting process is completed, the preliminary blow core 46 is separated from the lip portion. Therefore, in order to separate the seal portion 46A of the preliminary blow core 46 from the lip portion of the preform P in the first space 40B, the piston 52 is moved in the direction of raising the cylinder shaft 40A via the direction switching valve 56. At the same time, the piston 54 is driven in the direction of raising the flange 40A1 of the cylinder shaft 40A through the direction switching valve 62 also in the second space 40C.

As described above, according to the present embodiment, for example, when it is not possible to add a cylinder for increasing the driving force, the same result as when adding a cylinder by forming a plurality of stages of space is obtained. can get.

In the present invention, in addition to the structure described in the above embodiment, for example, a structure in which the pressure is changed only by the main drive section may be adopted. In this case, of course, similar to the above-described embodiment, the detachment driving force of the air cylinder forming the main drive portion is set only during the initial drive when the preliminary blow core is detached from the lip portion of the preform. It is necessary to increase To this end, it suffices to take measures such as providing a flow rate control mechanism that changes the driving force of the air cylinder only at the time of initial driving in which the preliminary blow core 46 is separated from the lip portion of the preform. Instead of this, the pressure increased more than the driving force at the time of insertion may be set not only at the initial stage of disengagement but also throughout the disengagement period. The point is that the driving force has only to be increased at the time of the initial driving to be disengaged, and thus the structure may be appropriately changed in accordance with this requirement.

Although the above embodiment has been described for the structure in which the temperature of the preform is controlled by performing the preliminary blow, the present invention is not limited to this structure. As an example, it is one of the temperature control structure that does not perform preliminary blow,
It is also possible to target a structure in which the temperature control core is brought into contact with the inner wall surface of the body of the preform, and even in this case,
Similar to the previous embodiment, at the initial stage of the detachment drive of the temperature control core,
Of course, it is possible to provide a structure for increasing the driving force.

[0055]

As described above, according to the present invention, the driving force at the initial stage of detaching the temperature adjusting means that can be inserted into and removed from the preform from the preform is increased to adjust the preform and the temperature. The time until the close contact with the means is released can be made uniform. Therefore, variations in temperature control time of the preform are eliminated and the preform is not overheated or overcooled, whereby the wall thickness distribution of the molded product can be set to a predetermined condition. .

[Brief description of drawings]

FIG. 1 is a plan view for explaining an overall configuration of a base used in a molding apparatus according to the present invention.

FIG. 2 is a front view showing an elevating / lowering drive unit of a temperature adjusting means in a temperature adjusting station of the molding apparatus shown in FIG.

FIG. 3 is a diagram for explaining a setting state of a driving force in the lifting drive unit shown in FIG.

FIG. 4 is a front view showing one mode of operation of the lifting drive unit shown in FIG.

5 is a cross-sectional view showing an example of a contact state between the temperature adjusting means side and the preform side in the mode shown in FIG.

FIG. 6 is a front view corresponding to FIG. 2 for explaining another embodiment of the present invention.

FIG. 7 is a schematic sectional view for explaining another embodiment of the present invention.

[Explanation of symbols]

 10 Molding Equipment 14 Temperature Control Station 30 Elevating / Driving Section 32 Guide Axis 40 Air Cylinder 40A Cylinder Axis 40B Actuator 40B First Space 40C Second Space 40C1 Supply / Discharge Port 46 Preliminary Blow Core 46A Sealing Part of Temperature Control Means 48 Return spring 50 Auxiliary cylinder 52, 54 Piston 56, 62 Directional switching valve

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[Procedure amendment]

[Submission date] April 14, 1994

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (7)

[Claims] 1. A molding apparatus having a structure in which a preform is placed in a temperature control pot before stretch blow molding to control the temperature distribution in the axial direction of the preform to an appropriate temperature for stretching. Means for adjusting the temperature of the inner layer of the preform, which is provided so that it can be inserted into and removed from the preform arranged in the pot, and can be brought into contact with the inner wall of the preform at the time of insertion; Drive means for respectively driving the adjusting means in the insertion / removal direction, wherein the drive means is at least during an initial drive for driving the temperature adjusting means to separate, and at least when separated from the inner wall of the preform. 2. A molding apparatus comprising a structure for increasing the detachment driving force of the temperature adjusting means. 2. The seal portion and the lip portion according to claim 1, wherein the temperature adjusting means is provided so as to be able to be inserted into and removed from the preform, and the lip portion of the preform is in contact with an inner wall of the lip portion during insertion. A heating piece for heating the portion immediately below, and a structure for performing pre-blowing with a pressure for bringing the preform into contact with the temperature control pot in a state where the seal portion is in contact with the inner wall of the lip portion. Molding device characterized by. 3. The temperature adjusting means according to claim 1, wherein the temperature adjusting means is provided so as to be insertable into and removable from the preform, and has a core that is in close contact with an inner wall of a body portion of the preform when the temperature is adjusted. A molding apparatus having a structure for setting a gap between a pot and a preform. 4. The main driving means according to claim 1, wherein the driving means drives the temperature adjusting means in an inserting / removing direction with respect to the preform arranged in the temperature adjusting pot. At least at the time of initial drive for detaching and driving the temperature adjusting means by the main driving means, and increasing the detaching driving force of the temperature adjusting means when the temperature adjusting means is detached from the inner wall of the preform. A molding device comprising: an auxiliary driving unit. 5. The molding apparatus according to claim 4, wherein the auxiliary driving means is elastically deformed when the temperature adjusting means is inserted and driven, and the elastic deforming force is released at an initial stage when the temperature adjusting means is detached and driven. A molding apparatus comprising a return spring for increasing a detachment driving force. 6. The molding apparatus according to claim 4, wherein the main drive means reciprocally drives a plate to which the auxiliary drive means is fixed, and the auxiliary drive means is short-circuited with the temperature adjusting means. A molding apparatus which reciprocates with a stroke, wherein at least the main drive means and the auxiliary drive means are driven at the same time during an initial drive in which the temperature adjusting means is driven to separate. 7. The molding apparatus according to claim 4, wherein both the main driving means and the auxiliary driving means are air cylinders, and a single rod for inserting and removing the temperature adjusting means and the rod are moved. A cylinder having a plurality of isolated spaces, and a plurality of pistons fixed to the rod at a position arranged in each of the spaces, and at least at the time of initial drive for separating and driving the temperature adjusting means, A molding apparatus, wherein air for driving a plurality of pistons simultaneously is introduced into the plurality of spaces.