JPH0280225A - Blow molding device - Google Patents

Abstract

PURPOSE:To prevent the end of a following parison continuously extrusion molded from intervening a split mold stopping in the given position by separating completely continuous extrusion molding of the parison from clamping of a foregoing parison by the split mold. CONSTITUTION:Just before cutting a parison P continuously extrusion molded from an extruder 4 at constant speed by the constant length, a chuck device 1 is positioned at the upper lifting limit with its chuck arm 10 open, while a split mold 50 corresponding with a blow molding device 5 in its open state moves right under a die head 40. When blocking of the chuck arm 10 is completed, a foregoing parison P1 naturally fallen slightly is clamped with the chuck arm 10 in the downward movement and moved downward together with the chuck device 1. The corresponding split mold 50 moved intermittently stops right under the die head 40 and waits for the foregoing parison P1 moved downward together with the chuck device 1. When the chuck device 1 comes to the lower limit, the clamping of the split mold 50 is completed and the split mold 50 clamps the parison P1 completely.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is a method of extruding a cylindrical parison continuously from an extruder and cutting it into a certain length using a split mold of a blow mold device. This relates to a blow molding device that blow molds products by sandwiching them.

[Conventional technology]

Conventional general blow molding equipment heats and melts a synthetic resin material, continuously extrudes the heated and molten synthetic resin material from a die head into a cylindrical parison, and then continuously extrudes the parison into a cylindrical parison. An extruder that cuts the length and a split mold are intermittently moved from the side directly below the die head, and the parison extruded and supplied by the extruder is sandwiched between the split molds to form weir bodies, etc. It consists of a blow mold device for blow molding products.

In this conventional blow molding equipment, when the parison extruded from the extruder reaches a certain length, the split mold located directly below the die head clamps the parison, and the split mold At the same time as the parison is sandwiched, the parison is cut, and then the split die holding the parison is immediately retracted from the position directly below the die head, and at the same time, the next split die which has opened the mold is moved to a position directly below the die head.

(Problems to be Solved by the Invention) In this way, in the conventional blow molding apparatus, the parison that is continuously extruded is directly sandwiched between the split molds that are stopped directly below the die head. At the time when the parison is sandwiched, the part of the parison sandwiched between the split molds is held so that it cannot move downward, but the next parison that is continuous with the previous parison, which is the part of the parison sandwiched between the split molds, is continuous. Since the parison is extruded and moved downward at a constant speed, the lower end of the parison may become caught in the split mold.

For this reason, in the past, the extrusion speed of the parison from the extruder was significantly limited to prevent the above-mentioned interference between the continuously extruded parison and the split mold.

However, limiting the extrusion speed of the parison reduces the manufacturing speed of the product.
Compared to the parison extrusion molding capacity of the extruder and the blow molding capacity of the blow mold apparatus, the production capacity of the blow molding apparatus as a whole was extremely low.

In addition, as mentioned above, the extrusion molding speed of the parison is limited, and the first parison sandwiched between the split molds and the next parison that is continuously extruded from the extruder are integrated, and the two are mutually interconnected. Since it is simply cut and separated without changing the positional relationship, it is physically impossible to completely eliminate interference with the split mold at the lower end of the next extruded parison, and this slight Deformation of the parison due to interference causes defective products.

For this reason, the length of the parison that is sandwiched between the split molds is made larger vertically than the length required for molding into the product, thereby preventing defective parts at both the top and bottom ends from being molded into the product. However, there was a dissatisfaction that a relatively large amount of non-product parts were molded when molding one product.

This means to prevent interference between the lower end of the next parison and the split mold is possible if cutting of the parison is achieved at the same time as the parison is sandwiched between the split molds, that is, if the forming of the first parison is achieved by cutting the parison. If so, immediately move the die head and the split mold away from each other in the vertical direction,
By separating the die head and the split mold from each other, the lower end of the next parison to be continuously extruded does not come into contact with the split mold.

Although the above-mentioned conventional means can certainly prevent interference between the lower end of the next parison and the split die, moving the die head and the split die relatively apart in the vertical direction means that It is necessary to be able to move either the extruder or the blow mold device in the vertical direction, and this movement must be performed in a state that allows accurate positioning of the die head or split mold. It goes without saying that large equipment is required to move the entire extruder or blow mold device, but there are also problems in that the structure of this equipment is complex and operation control is troublesome. .

Therefore, the present invention was devised in order to solve the problems in the prior art described above.The die head and the split mold are positioned apart from each other in advance, and the product of the parison is continuously extruded. By feeding only the tip parison, which is the part to be molded, to a split mold located separately,
It is an object of the present invention to enable the extrusion molding speed of the parison to be sufficiently increased without causing interference between the split mold and the next parison.

Another object is to reliably achieve puff blowing while keeping the extrusion speed of the parison sufficiently high.

[Means to solve the problem]

Means of the present invention to achieve the above object is to have an extruder that heats and melts a synthetic resin material and continuously extrudes it from a die head into a cylindrical or bottomed cylindrical parison, and extrudes from the die head of this extruder. The upper end of the parison, which has been formed and cut to a certain length, is not laterally crushed by a pair of chuck arms. and a blow mold device for intermittently moving the split mold below the die head of the extruder to a stopping position, sandwiching the supplied parison between the split mold and blow-molding it into a product. .

In addition to the above-mentioned means, the lower end of the next parison extruded from the die head is flattened and sealed by a pair of sealer arms from the lateral direction, and the lower end of the next parison extruded from the die head is welded and sealed, and the tip of the parison that is held by the chuck arms is The objective is to add a function to seal the upward opening of the parison.

The chuck device is rotatably provided with a pair of chuck pinions that individually mesh with the rack teeth of a chuck rack that has rack teeth on both left and right sides and is driven to move back and forth, and a chuck arm attached to each of the chuck pinions. Basically, the proximal end of the chuck arm is fixed immovably, and chuck tooth pieces, which are made by dividing a flat ring plate with an inner diameter slightly smaller than the outer diameter of the parison, are attached to the opposing tips of the pair of chuck arms. In addition to this chuck function, a pair of sealer pinions are rotatably provided that individually mesh with the rack teeth of a sealer rack that has rack teeth on both left and right sides and is driven to move back and forth. The base end of the sealer arm is fixed immovably, and the opposing tips of the pair of sealer arms are
A sealer piece having an opposing surface with the remaining part following the flat crushing surface portion at the lower end as an outwardly inclined flank surface, and a close contact portion between the opposing surface for close contact and the chuck tooth piece immediately below the sealer piece. It is preferable to add a sealer function part which is constructed by attaching an air molaze piece and positioning the sealer arm to which this sealer piece and air molaze piece are attached directly above the chuck arm.

[Effect]

In contrast to the extruder, the chuck device has the tip of its chuck arm located directly below the die head so that it can be opened and closed laterally, and the parison that is continuously extruded from the die head of the extruder at a constant speed is in an open state. It hangs down between the tips of both chuck arms.

When the extruded parison has reached a predetermined length, it is cut by appropriate means, and at the same time as the parison is cut, both chuck arms, which are in the open state, are closed and the lifting device is activated. The chuck device, which is located at its upper limit, is displaced downward at a lowering speed that is greater than the extrusion molding speed of the parison. That is, cutting the parison, holding the parison with a chuck device,
The timing of the start of the downward movement of the chuck device may be such that the chuck device clamps the previous parison after the parison has been cut, or the parison is cut after the chuck device has clamped the parison. If the parison is cut and separated from the extruder,
- Although it falls instantaneously, it is immediately clamped by the chuck device that has started its downward movement, and in the latter case, the chuck device simultaneously achieves the clamping of the parison, or the chuck device simultaneously moves downward and cuts the parison; Alternatively, the parison can be clamped by the chuck device immediately after the chuck device starts moving downward, and the parison can be cut at the same time as the chuck device achieves clamping of the parison. Therefore, as long as the extrusion molding speed of the parison is not higher than the free fall speed of the first parison, the upper end of the first parison will definitely separate from the lower end of the next parison, and the downward displacement speed of the chuck device that clamps the first parison will be Since the extrusion speed is higher than the parison extrusion speed, when the first parison held by the chuck device reaches the lowering limit position, the upper end of the first parison and the lower end of the next parison are sufficiently separated.

At the time when the chuck device starts its downward displacement, the split mold is in an open state below the die head and is waiting to stop. The tip parison directly enters between the split molds. After confirming that the chuck device has descended to its lower limit, the split molds are clamped, thereby achieving the clamping of the parison by the split molds.

When the split molds have clamped the first parison, that is, when the split molds are in the closed state, the chuck arm is opened to release the first parison from the chuck device, and then the lifting device is operated to remove the first parison from the chuck device. It returns to the upper limit and enters the standby state.

The split die waits for the chuck device to move upward, and then moves intermittently at appropriate times, and the next split die remains open and moves to a position below the die head.

In addition, the sealer function part by the sealer arm closes the sealer arm after the chuck arm completes the clamping of the previous parison, that is, after the chuck arm has passed, and when the lower end of the next parison reaches almost directly above the chuck arm, the sealer arm closes the next parison. The chunk function part of the chuck arm that holds the open lower end of the parison flat from the side and then welds and seals it with the welding force of the parison itself, and at the same time holds the upper end of the parison in an open state. In close contact with the parison, the upward opening of the parison is sealed to prevent blow air from being puff-blown from inside the parison.

This opening/closing operation of the sealer arm is completed in a very short time, and the lowering operation of the chuck device by the elevating device is started almost simultaneously with the opening and return of the sealer arm.

The chuck device has a chuck arm attached to each of a pair of pinions that are rotationally driven by a single rack, so the opening and closing operations of both chuck arms are achieved in perfect synchronization by the forward and backward movement of the rack. At the same time, the amount of oscillation becomes completely equal. Similarly, since a sealer arm is attached to each of a pair of pinions that are rotationally driven by a single rack, the opening and closing operations of both sealer arms are completely synchronized by the forward and backward movement of the rack, and the amount of rocking is can be made completely equal.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 are diagrams showing the positional relationship of each component of the blow molding apparatus according to the present invention, below (directly below in the case of the illustrated embodiment) a die head 40 of a conventionally well-known extruder 4.
In this case, a large number of split molds 50, which are arranged at each center angle, are set to stop at the periphery of a turntable which is rotated intermittently at a constant center angle in a conventionally well-known blow mold device 5. The chuck device 1 is attached to the upper end of the elevating rod 30 of the elevating device 3 which is placed upright near the blow mold device 5.

The elevating device 3 is assembled to an elevating guide body 31 that supports an elevating rod 30 in the form of a straight bar so that it can be moved up and down while maintaining it in an upright position, and is an oscillating handler placed on the side of this elevating guide body 31. It is constructed by attaching the proximal end of a connecting arm 34 whose distal end is pin-bonded to the lifting rod 31 to the swinging tip of a swing arm 33 that is swing-driven at a constant swing angle by a certain driver 32. .

The chuck device 1 is attached to the upper end of the lifting rod 31 of the lifting device 3 via the arm 19 and the base 1. In the embodiment shown in FIGS. 3 and 4, guide side frames 13 are attached between both side ends of a pair of upper and lower frame plates 12 that are in the form of an elongated flat plate, thereby creating a frame body with the center open for communication back and forth. A chuck drive cylinder 17, which is fixed to the rear end of this frame, is supported by both guide side frames 13 so as to be able to slide in the front and back direction without wobbling at the tip of the piston rond of the chuck drive cylinder 17. A slide piece 16 is arranged between both frame plates 12, and at the tip of this chuck slide piece 16, it is similarly supported slidably in the front and back direction by both guide side frames 13, and has equal rack teeth on both sides. The chuck racks 15 provided with a The proximal end of the chuck arm 10 is immovably fixed to each of them. A chuck tooth piece 11, which is made by dividing a flat ring plate into two parts and having an inner diameter slightly smaller than the outer diameter of the parison P, is attached to the mutually opposing tips of both chuck arms 10, and the parison P to be formed is Changes in diameter can be easily accommodated by replacing the chuck teeth 11.

The parison P is held between the chuck teeth 11 by slightly biting the inner peripheral edge of the chuck tooth 11 into the outer peripheral surface of the parison P, which has just been extruded and is still soft.

Furthermore, the embodiments of the chuck device 1 shown in FIGS. 5 to 11 are the embodiments shown in FIGS. 3 and 4 with a sealer function added, and a sealer drive cylinder 27.
, a sealer slide piece 26, a sealer rack 25, a sealer pinion 24, and a sealer arm 20 are assembled in exactly the same configuration as the chuck function part and are arranged on the chuck function part. A sealer piece 21 and an air morase piece 23, each of which is obtained by dividing a flat circular plate into two, are attached to the opposing tips of both sealer arms 20, and the opposing surfaces 22 of both sealer pieces 21 have lower ends. The air morase piece 23 (see especially FIG. 11), which is integrally attached directly below the sealer piece 21, has a flat crushed surface part and the remaining part is an upwardly sloped flank part. When the arm 20 is closed, it has opposing surfaces that are in close contact with each other, and a semi-cylindrical piece whose inner circumferential surface is in close contact with the outer circumferential surface of the cylindrical piece that protrudes upward from the chuck tooth piece 11 located directly below. .

Therefore, as shown in FIGS. 10 and 11, when both sealer pieces 21 sandwich the lower end of the next parison P2, the lower end of the next parison P2 is flattened by the seal facing surface 22. Particularly, at the lower end facing the crushing surface portion that is strongly crushed, the welding force of the next parison P2 itself will cause complete contact. Further, at the same time as the sealer piece 21 achieves hermetic welding of the lower end of the next parison P2, both air molese pieces 23 bring their opposing surfaces into close contact, and the inner circumferential surface of the semi-cylindrical piece with a hanging film is attached to the chuck teeth. 11, the upper end opening of the tip parison P1 held by both chuck tooth pieces 11 is sealed by both air morase pieces 23, so that the blow air in the puff-blown tip parison P1 cannot be extracted. blocked.

In this way, in the embodiments shown in FIGS. 5 to 11, the lower end of the next parison P2 can be completely sealed, and the blowing air in the first parison Pl is prevented from coming out. This means that the puff blow molding procedure can be carried out easily.

As shown in FIG. 12, by removably assembling a seal jig 41 to the parison extrusion port of the die head 40, the extruder 4 can directly extrude a parison P in the shape of a cylinder with a bottom. In this case, the sealer piece 21 becomes unnecessary.

Further, this puff blow molding is particularly used for molding large blown products, and is effective for making the wall thickness distribution of large blown products as uniform as possible.

Next, an example of the operation of the embodiment shown in FIGS. 1 to 4 will be described with reference to FIGS. 13 and 14.

Immediately before cutting a certain length of the parison P that is continuously extruded from the extruder 4 at a constant speed, that is, immediately before cutting, the chuck device 1 is at its upper limit and the chuck arm 10 is in an open state. The corresponding split mold 50 of the blow mold device 5 is in the open position when the die head 4 is opened.
It is moving directly below 0. The mutual relationship between the parison P and the chuck arm 10 at this point is shown in FIG. 14(a).
The state is shown in (a').

When time t1 comes from this state, FIG. 14(b)(b'
), at the same time as the parison P is cut,
The elevating device 3 operates and the chuck device 1 begins to descend, and the chuck drive cylinder 17 operates to move the chuck rank 15 backward, so that the chuck arm 10 begins to close. Therefore, at this time t1, the canted parison P1 starts falling naturally, but the chatter arm 1
0 has just started the closing operation, so it has not yet clamped the previous parison P1.

At time t2, which is a short time after time t1, the first
As shown in FIGS. 4(c) and 4(c''), as the chuck arm 10 is completely closed, the parison PL, which has slightly fallen by itself, is held by the chuck arm 10 that is moving downward, and is held together with the chuck device I. Move down.

At time t3, which is a short time after time t2, the first
As shown in FIGS. 4(d) and 4(d'), the corresponding split mold 50 that has moved intermittently stops directly below the die head 40.
The parison P1 descending together with the chuck device 1 is awaited.

The downward movement of the chuck device 1 is completed at time t5, but at time t4 immediately before this time t5, as shown in FIG.
) As shown in (e'), the clamping operation of the split mold 50 is started. This is to shorten the time required to blow mold one product as much as possible, and there is a correlation between the fact that the clamping speed of the split mold 50 is slower than the descending speed of the chuck device l. Therefore, it is possible.

Time t after the chuck device 1 reaches the lower limit at time t5
6, as shown in FIGS. 14(f) and (f'), the clamping of the split mold 50 is completed and the split mold 50 is placed first on the parison P.
Pinch I completely.

At time t7, which is immediately after time t6 when the split mold 50 has completely sandwiched the parison PL, the chuck rack 15 moves forward due to the return operation of the chuck drive cylinder 17, and the chuck arm 10 begins to open. Figure 14 (g
)(g'), the chuck device 1 is completely opened at time t8, and the grip on the previous parison P1 by the chuck device 1 is released. The previous parison P1 by this chuck device 1
Once the release of the clamp has been achieved for the immediately following time t
At step 9, the lifting device 3 is operated to return the chuck device 1 to its raised position (see FIGS. 14(h) and 14(h')), and the chuck device 1 is kept on standby at the upper limit.

The split die 50 holding the previous parison P1 starts moving at a time t11 after the time tlo when the chuck device 1 returns to its upper limit, and retreats from directly below the die head 40.

〔Effect of the invention〕

Since the blow molding apparatus according to the present invention has the above-described configuration, it exhibits the following effects.

The parison is continuously extruded at a constant speed, cut to a certain length, and separated from the extruder. The parison is then transported to a split mold of a blow mold device located away from the extruder and sandwiched therein. Therefore, the continuous extrusion of parisons by the extruder and the sandwiching of the previous parison by the split mold can be completely separated, and this allows the tip of the next parison that is continuously extruded to be in the specified position. There is no interference with the stopped split mold.

Therefore, there is no need to limit the extrusion molding speed of the parison from the extruder in consideration of interference with the split mold.
Since the parison extrusion molding speed can be sufficiently increased, the product manufacturing capacity can be dramatically increased. Further, since there is no occurrence of defective deformation due to interference of the tip of the next parison with the split die during extrusion molding from the extruder, it is possible to completely eliminate the occurrence of defective products due to defective deformation of this parison.

In addition, since the parison that is extruded and blow molded and the parison that is being extruded are handled completely separately,
The treatment of the parison during extrusion, ie the process of welding and sealing the lower end of the parison during extrusion, can be achieved simply, reliably and accurately, which results in a good and simple implementation of the puff blowing means.

[Brief explanation of the drawing]

FIG. 1 is an overall front view showing the arrangement of each component of an embodiment of the device of the present invention. FIG. 2 is an overall plan view of the embodiment shown in FIG. 1. FIG. 3 is a partially cutaway plan view showing an embodiment of a chuck device which is a main component of the device of the present invention. FIG. 4 is an overall side view of the chuck device shown in FIG. 3. FIG. 5 is a partially cutaway plan view showing another embodiment of the chuck device. FIG. 6 is a partial plan view of the chuck device shown in FIG. 5 with the sealer function portion in a closed state. FIG. 7 is an overall side view of the chuck device shown in FIG. 5. FIG. 8 is a perspective view showing the state of the chuck device shown in FIG. 5 when the first parison is chucked. FIG. 9 is a longitudinal cross-sectional view showing the front parison chuck state by the chunk teeth when the front parison is chucked as shown in FIG. 8. FIG. 10 is a perspective view showing the state of the front parison chuck and the next parison seal of the chuck device shown in FIG. 5. FIG. 11 is a longitudinal cross-sectional view showing the relationship between the chuck tooth piece, the air morase piece, and the parison during sealing of the first parison chuck and the next parison shown in FIG. 10. FIG. 12 is a longitudinal sectional view showing an example of the die head structure of an extruder for forming a bottomed parison. FIG. 13 is a timing chart diagram showing the timing relationship of the operations of each component in the device of the present invention. FIG. 14 is an explanatory diagram showing the mutual positions and state relationships of the respective constituent parts at the time of main operation of the apparatus of the present invention, and the relationship between the open and closed states of the chuck arm. Explanation of symbols 1; Chunk device, 10; Chuck arm, 11; Chuck tooth piece, I2; Frame plate, 13; Guide side frame, 14: Pinion for chuck, 15; Rack for chuck, 16; Slide piece for chuck, 17 ;Chuck drive cylinder, 18;
Installation is on the base, 19; Installation is on the arm, 20; Sheila arm,
21; Sealer piece, 23; Air morase piece, 24; Pinion for sealer, 25; Rank for sealer, 26; Slide piece for sealer, 27; Drive cylinder for sealer, 3; Lifting device, 30; Lifting rond, 31; Lifting guide Body, 32; Drive body, 33; Swing arm, 34; Connection arm, 4; Extruder, 40; Die head, 5; Blow mold device, 50;
Split mold, P: parison, Pl: previous parison, P2: next parison. Applicant: Yoshino Kogyo Co., Ltd. zu β 姶 wo (a) (b) (a') (b) /$＃諧(e) (f) (e) (f) ２→Go sweat crawl Nitango ado

Claims (4)

[Claims] (1) An extruder that heats and melts a synthetic resin material and continuously extrudes it from a die head into a cylindrical or bottomed cylindrical parison; A chuck device that clamps the upper end of the front parison from the side without crushing it between a pair of chuck arms; An elevating device that supports and moves the chuck device up and down; A split mold is placed below the die head of the extruder. A blow molding apparatus comprising: a blow molding apparatus that is moved intermittently to a stop position, and blow-moldes the supplied parison into a product by sandwiching the supplied parison between the split molds. (2) An extruder that heats and melts a synthetic resin material and continuously extrudes it from a die head into a cylindrical parison, and an upper end of the parison that is extruded from the die head of the extruder and cut into a certain length. is clamped by a pair of chuck arms without crushing it from the lateral direction, and the lower end of the next parison extruded from the die head is flattened from the lateral direction by a pair of sealer arms to seal it by welding. a chuck device that seals the upward opening of the parison held by the chuck arms; an elevating device that supports and moves the chuck device up and down; and an intermittently moved split die below the die head of the extruder. and a blow mold device for blow-molding the first parison into a product by inserting the first parison into the split mold. (3) A pair of chuck pinions that individually mesh with the rack teeth of a chuck rack that has rack teeth on both left and right sides and is driven to move back and forth are rotatably provided, and a chuck arm is attached to each of the chuck pinions. A chuck device is constructed by fixing the proximal end of the chuck arm immovably, and attaching chuck tooth pieces, which are made by dividing a flat ring plate with an inner diameter slightly smaller than the outer diameter of the parison, to the opposing tips of the pair of chatch arms. Item 2. The blow molding apparatus according to item 1 or 2. (4) A pair of sealer pinions that individually mesh with the rack teeth of a sealer rack that has rack teeth on both left and right sides and is driven to move back and forth are rotatably provided, and a sealer arm is attached to each of the sealer pinions. a sealer piece whose base ends are immovably fixed, and which has opposing surfaces at the opposing tips of the pair of sealer arms, with the remaining portion following the flat crushed surface portion at the lower end portion being an outwardly inclined flank surface; An air molaze piece having an opposing surface for close contact and a close contact portion with the chuck tooth piece is attached directly below the sealer piece, and the sealer arm to which the sealer piece and air molaze piece are attached is positioned directly above the chuck arm to chuck. The blow molding apparatus according to claim 2, further comprising a blow molding apparatus.