JP2003103613A - Blow molding apparatus for blow molded article and molding method for blow molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for easily treating burr formed on the periphery of a blow molded article. SOLUTION: In the blow molding apparatus 1 for manufacturing the blow molded article P by blow molding by holding a molding compound W between a pair of molds 3a and 3b and blowing air into the molding compound W to allow the molding compound W to follow the cavities 30a and 30b provided to the molds 3a and 3b, a pair of the molds 3a and 3b are equipped with molding parts 31a and 31b forming the cavities 30a and 30b and the clamp parts 32a and 32b provided along the peripheral edges of the molding parts 31a and 31b to clamp the molding compound W. Further, the molds 3a and 3b are constituted so that at least one of the molding parts 31a and 31b and the clamp parts 32a and 32b are relatively moved with respect to the other one of them and the burr comprising the molding compound W clamped by the clamp parts 32a and 32b is separated from the blow molded article P.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow molding product in which a molding material is sandwiched between a pair of molding dies, gas is blown into the molding material, and the molding material is made to follow a cavity provided in the molding die. Blow molding technology.

[0002]

2. Description of the Related Art In the conventional method for molding a hollow molded article, for example, a molding material made of a thermoplastic resin is extruded into a pipe shape (hot parison method) or two plate shapes (hot sheet method). The just extruded still soft molding material is clamped by a pair of molding dies. Then, air is blown into the molding material so that the molding material follows the cavity provided in the molding die, whereby the hollow molded article is blow-molded. Then, after cooling and solidifying the molding material, the molding die was opened and the hollow molded article was demolded.

[0003]

However, burrs are formed in the conventional demolded hollow molded article. That is, the hollow molding product is molded by the molding material formed in the cavity of the molding die, but the molding material protruding from the cavity becomes a burr of the hollow molding product by being sandwiched by the pair of molding dies, and the hollow molding product is formed. It was attached around the item. Therefore, conventionally, it was necessary to process burrs as follows, for example. That is, the burr is torn off from the hollow molded product by hand, or the burr is removed from the hollow molded product with a blade or the like. Then, the small burrs that were not removed in these steps were also melted by the burner, and the burrs were processed by this. Therefore, the conventional burr treatment is troublesome because it needs to be performed after blow molding. Therefore, in view of the above problems, it is an object of the present invention to provide a technique for easily treating burrs formed around a hollow molded product.

[0004]

In order to solve the above-mentioned problems, the present invention provides a blow-molding apparatus for a hollow-molded article and a method for molding a hollow-molded article, each of which has a structure as described in the above claims. Characterize. According to the invention as set forth in claim 1, the molding material is sandwiched between a pair of molding dies, gas is blown into the molding material, and the molding material is made to follow the cavity provided in the molding die. It is a blow molding device for blow molding a product. Each of the pair of molding dies includes a molding portion that forms a cavity, and a clamp portion that is provided along the peripheral edge of the molding portion and that sandwiches the molding material. Further, the pair of molding dies has a structure in which at least one of the molding part and the clamp part moves relative to the other, thereby separating the burr made of the molding material sandwiched by the clamp parts from the hollow molded product. There is.

That is, the molding part has a cavity, and the hollow molding is held in this cavity. On the other hand, the clamp part is provided along the peripheral edge of the molding part,
The clamp part sandwiches the molding material protruding from the molding part.
And in this state, one of the molding part or the clamp part,
Alternatively, both are moved so that they are relatively out of position. Therefore, the molding material sandwiched by the clamp portions is separated from the hollow molded product held in the molding portion. For example, it may be shredded, sheared, or cut. Therefore, the burr made of the molding material sandwiched by the clamp portions is easily separated from the hollow molded article by the molding die. Therefore, the burr of the hollow molded product formed around the hollow molded product is easily treated, whereby the manufacturing cost of the hollow molded product is reduced or the manufacturing time of the hollow molded product is shortened.
Although the clamp portion is provided along the peripheral edge of the molding portion, the clamp portion may be provided along the entire circumference of the peripheral edge of the molding portion, or may be along a part thereof. Further, the state along the line may be either a form provided without a gap between the clamp part and the molding part or a form provided with a predetermined gap.

According to the invention of claim 2, claim 1
In the blow molding apparatus described in (1), a melting unit for melting a part of the molding material is provided in the peripheral portion of the molding unit. By the way, a hollow molded product is easily formed with a burr, and this burr is formed by sandwiching a molding material protruding from a cavity between a pair of molding dies. The blow molding device according to the first aspect of the present invention has a structure for removing large burrs. That is, the molding material protruding from the molding portion having the cavity is separated from the hollow molding product molded in the cavity.

According to the second aspect of the invention, a structure for removing small burrs is also provided. That is, the molding material protruding from the cavity and not protruding from the molding part,
The hollow molding product is provided with a melting means for melting a molding material arranged on the peripheral side of the molding portion, which can be a small burr. Therefore, the melting means melts the molding material that becomes small burrs, and the melted molding material melts away from the hollow molded product or melts into the hollow molded product side. As a result, small burrs are easily processed by the melting means. Therefore, the manufacturing cost of the hollow molded product is reduced, and the manufacturing time of the hollow molded product is shortened. It should be noted that the melting means may be any means as long as it melts the molding material, for example, a structure including a heater that generates heat, a structure that melts the molding material by high frequency, or a structure that melts the molding material by ultrasonic waves. Further, the melting means is provided in the molding part, but the melting means may be provided in both of the pair of molding parts provided in the blow molding device, or may be provided in only one molding part. It may be.

According to the third aspect of the invention, the molding material is arranged between the pair of molding dies in the mold open state. Then, the molding material is closed with a pair of molding dies. next,
A hollow molded article is blow-molded by blowing gas into the molding material and thereby causing the molding material to follow the cavity formed in the molding portion of the molding die. Then, at least one of the molding portion of the molding die or the clamp portion provided along the peripheral portion of the molding portion and sandwiching the molding material is moved relatively to the other. That is, by moving one or both of the molding section and the clamp section, these positions are relatively displaced. By this movement, the burr made of the molding material sandwiched by the clamp portions is separated from the hollow molded product.

That is, as the molding material, a hollow molded article is molded in the cavity of the molding portion. Then, the molding material protruding from the molding portion is sandwiched by the clamp portions. Therefore, when the molding part and the clamp part are moved relative to each other, the molding material sandwiched by the clamp part is separated from the hollow molded product. For example, it may be shredded, sheared, or cut. Therefore, the burr made of the molding material sandwiched by the clamp portions is easily separated from the hollow molded article by the molding die. Therefore, the burr of the hollow molded product formed around the hollow molded product is easily treated, which reduces the manufacturing cost of the hollow molded product or shortens the manufacturing time of the hollow molded product.

According to the invention of claim 4, claim 3
The method for forming a hollow molded article according to claim 1, wherein the burr made of the molding material sandwiched by the clamps is separated from the hollow molded article, or at the same time when the burr is separated by a melting means provided in the peripheral portion of the molding section. This is a molding method in which a part of the molding material is melted. Therefore, of the burrs formed on the hollow molded product, the portion that becomes a small burr is removed by the melting means. That is, the hollow molded product is easily formed with burrs, but the burrs are formed by sandwiching the molding material protruding from the cavity between a pair of molding dies. And according to the molding method of claim 3,
The molding material protruding from the molding portion forming the cavity and the hollow molded product molded in the cavity are separated from each other. According to the invention as set forth in claim 4, the molding material is protruded from the cavity and is not protruded from the molding portion, and the molding material is arranged on a portion which can be a small burr of the hollow molded product, that is, on the peripheral side of the molding portion. The molding material is melted by the melting means. Therefore, the molding material that becomes small burrs is melted and melts away from the hollow molded product molded in the cavity, or melts into the hollow molded product side. As a result, small burrs are easily processed by the melting means. Therefore, the manufacturing cost of the hollow molded product is reduced, and the manufacturing time of the hollow molded product is shortened.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is a technique for molding a hollow molded article P by blow molding (hollow molding, blow molding) a thermoplastic synthetic resin material. An embodiment of a method for molding a hollow molded article P and a blow molding apparatus 1 according to this technique will be described with reference to the drawings. In addition, this device 1
The hollow molded product P according to (1) is, for example, a visor main body of a sun visor for a vehicle, and the visor main body is a member that is formed into a hollow plate shape and serves as a core member that blocks light into the vehicle interior.
The device 1 is for molding a visor body, for example,
As shown in FIG. 1, extrusion means 2 for extruding the molding material W, mold clamping means 3 for clamping the molding material W extruded from the extrusion means 2, and molding material W clamped by the mold clamping means 3.
And a blowing means 4 for blowing gas into the interior of the.

The extruding means 2 is means for extruding a thermoplastic resin, which is a raw material of the molding material W, by heating and plasticizing it, and extruding the plasticized material into a tubular shape or two sheet shapes. The extruding means 2 shown in FIG. 1 shows a state in which the molding material W is extruded in a tubular shape, and the extruded molding material W hangs downward due to its own weight. The molding material W extruded in a tubular shape is generally called a parison.

The blowing means 4 is a means which is inserted into the molding material W and blows a gas (for example, air) into the molding material W during mold clamping. This blowing means 4 is
As shown in FIG. 1, a tube 40 and a nozzle 41 provided at the tip of the tube 40 are mainly configured, and the tube 4
The gas is blown out from the nozzle 41 via 0. Then, these are inserted from the lower end opening of the molding material W (parison), whereby one end side of the blowing means 4 is arranged inside the molding material W. Then, the molding material W is clamped by the mold clamping means 3, and in that state, gas is blown into the molding material W by the blowing means 4. As a result, a hollow portion is formed inside the molding material W, and the molding material W is blow-molded along the cavities 30a and 30b provided in the mold clamping means 3 as described later.

Further, as shown in FIG. 1, a hollow portion disposing member 42 is detachably attached to the nozzle 41 in advance, and in this state, the nozzle 41 is arranged inside the molding material W. Therefore, the hollow portion disposing member 42 is provided inside the hollow molded product P by blow molding the hollow molded product P.
The hollow portion arranging member 42 is a bearing member that is a component of a product provided in the hollow portion of the hollow molded product P, and is, for example, a component of the visor body. The bearing member is provided in the hollow portion of the visor body, prevents the spindle inserted into the visor body from coming off, and supports the spindle rotatably. Therefore, the visor body is
It is rotatably attached to the support shaft via a bearing member.

The mold clamping means 2 is means for clamping and opening the molding material W, and as shown in FIG.
Has a pair of molding dies 3a, 3b sandwiching the left and right sides.
As shown in FIGS. 1 and 2, these molding dies 3a and 3b have concave cavities 30a and 3 corresponding to the shape of the hollow molded product P.
0b respectively, and a closed space for molding the hollow molded product P is formed by these cavities 30a and 30b. Further, the mold clamping means 2 is for molding a plurality (for example, two) of hollow molded products P at a time as shown in FIG. 1, and the molding dies 3a and 3b have a plurality of cavities 30a and 30b, respectively. .

The molds 3a and 3b are composed of a plurality of parts as shown in FIGS. That is, each of the molding dies 3a and 3b has a plurality of molding parts 31a and 31b and one clamp part 32a and 3b as shown in FIG.
2b, one outer frame portion 33a, 33b, and one base portion 3
4a and 34b. Forming part 31
a and 31b are the cavities 3 as shown in FIG.
This is a part including 0a and 30b. And the molding section 31
The outer peripheral shapes of a and 31b are almost the same as the outer peripheral shapes of the cavities 30a and 30b.
The shape is one size larger than b. Therefore, the molding portions 31a and 31b form end surfaces 36a and 36b at their peripheral portions as shown in FIG. And these end faces 36
As shown in FIG. 6, the a and 36b cooperate with each other to sandwich the molding material W when the molding dies 3a and 3b are in the mold clamping state.

The clamp parts 32a and 32b are shown in FIG.
As shown in FIG. 2, the outer frame portions 33a and 33b are provided along the entire circumference of the peripheral edges of the molded portions 31a and 31b.
This is a portion provided along the entire circumference of the peripheral edges of the clamp portions 32a and 32b. The molding portions 31a and 31b and the outer frame portions 33a and 33b are, as shown in FIGS.
34b is formed integrally with or is attached integrally. Therefore, the molding portions 31a and 31b and the outer frame portion 3
3a and 33b are fixed to the bases 34a and 34b.

On the other hand, the clamp portions 32a and 32b are provided at the base 3
4a and 34b are configured to be movable so as to be able to approach and separate from each other. As shown in FIGS. 2 and 3, the movement is such that the gap formed between the outer frame portions 33a and 33b and the molding portions 31a and 31b is moved. The moving direction of the clamp portions 32a and 32b is the thickness direction of the molding dies 3a and 3b, that is, the molding die 3 as shown in FIG.
It is almost the same as the mold clamping direction of a and 3b.

In other words, the clamp parts 32a and 32b can be said to have a structure which moves relative to the molding part 31a as shown in FIG. And these clamp parts 3
As for 2a and 32b, one (32b) is configured to move so as to be retractable by using a hydraulic cylinder as shown in FIG. 3, and the other (32a) uses elastic force of an elastic material and one ( It is configured to be able to move in and out by being pushed by 32b).

As shown in FIG. 3, one clamp portion 32b includes an operating hydraulic cylinder 50 and the operating hydraulic cylinder 50.
Is connected to the drive means 5 including two auxiliary hydraulic cylinders 51 for assisting. Therefore, the clamp portion 32
b is moved in a direction away from the base portion 34b when the rods 50a and 51a of these cylinders are extended by hydraulic pressure, and is moved in a direction close to the base portion 34b when the rods 50a and 51a are compressed by hydraulic pressure. Further, since the clamp portion 32b is moved by the plurality of cylinders, the clamp portion 32b is likely to move in parallel.

As shown in FIG. 3, the other clamp portion 32a is mainly composed of an elastic member such as a coil spring 53 and a guide rod 52 for guiding the movement of the clamp portion 32a. As shown in FIG. 3, the guide rod 52 penetrates a through hole provided in the base portion 34a, and one end thereof is connected to the back surface of the clamp portion 32a. And the guide rod 5
The other end of 2 is provided with a flange 52a, which prevents the guide rod 52 from coming off the through hole. Therefore, the clamp portion 32a is guided by the guide rod 52 and moves relative to the base portion 34a.

As shown in FIG. 3, the coil spring 53 is spirally wound and molded, and the guide rod 52 is inserted in the center side thereof. The coil spring 53 is shown in FIG.
As shown in FIG. 5, it is arranged between the base portion 34a and the clamp portion 32a, and its elastic force urges the clamp portion 32a in the separating direction with respect to the base portion 34a. Accordingly, the clamp portion 32a is pushed by the clamp portion 32b to approach the base portion 34a, and the clamp portion 32a
When it is not pushed by b, it is separated from the base 34a.

As shown in FIG. 2, the molding parts 31a and 31b are provided with melting means 6 for melting the molding material W at their peripheral portions. In other words, the molding parts 31a and 31b
1 has cavities 30a and 30b as shown in FIG. 1, and has melting means 6 along the outer peripheries of the cavities 30a and 30b. Alternatively, the molding parts 31a, 31b
In other words, it can be said that the melting means 6 is provided in the vicinity of the end faces 36a and 36b formed in the peripheral portion.

As shown in FIG. 2, the melting means 6 has heaters 60a and 60b which generate heat when an electric current is applied, and a lead wire 61 for sending an electric current to the heaters 60a and 60b.
The main components are a and 61b. Therefore, when the heaters 60a and 60b generate heat while the molding material W is arranged near the heaters 60a and 60b, the heat melts the molding material W. That is, the molding material W is clamped by the mold clamping means 3, and at this time, the heaters 60a, 60b.
The molding material W arranged in the vicinity of the cavity 30, that is, the cavity 30
Part of the molding material W protruding from the a and 30b and part of the molding material W disposed on the peripheral side of the cavities 30a and 30b are melted by the heat of the heaters 60a and 60b.

Further, as shown in FIG. 1, the molding die 3a is provided with a groove 35a communicating with each cavity 30a.
The groove 35a is provided with the tube 40 of the blowing means 4 sandwiched between the molding dies 3a and 3b when the molding dies 3a and 3b clamp the molding material W, so that the tube 40 is not crushed by this. It is for doing. Therefore, the blowing means 4 can blow the gas into the molding material W even when the mold is clamped. Then, the tube 40 and the nozzle 41 remain in the groove 35a while the mold is clamped.
It is also possible to pull out from these molding dies 3a and 3b by utilizing. The other mold 3b is also provided with a similar groove (not shown in the figure).

The device 1 is configured as described above. Then, the hollow molded product P is molded by the device 1 as follows. That is, as shown in FIG. 1, the extrusion means 2 extrudes the molding material W into a tubular shape (or a shape of two sheets). Then, from the lower open end of the extruded molding material W, as shown in FIG.
As shown in (a), the tip side of the blowing means 4 and the nozzle 4
The hollow portion disposing member 42, which has been mounted in advance in No. 1, is inserted (between) inside the molding material W.

Next, a pair of molding dies 3a and 3b are installed in FIG. 4 (b).
The still soft molding material W just extruded is clamped close to each other as shown in FIG. At this time (as shown in FIG. 2), the clamp portion 32b is adjusted by the driving means 5 so that the end surface 37b is substantially flush with the end surface 36b of the molding portion 31b. As a result, the clamp portion 32a is pushed by the clamp portion 32b, and the end surface 37a of the clamp portion 32a becomes flush with the end surface 36a of the molding portion 31a.

Therefore, the molding material W is sandwiched between the pair of clamp portions 32a and 32b and the pair of molding portions 31a and 31b as shown in FIG. 4 (b). Then, the gas is sent into the molding material W by the blowing means 4. As a result, the molding material W has a hollow portion formed inside, and the outer surface has a cavity 30.
Follow the molding surface that is the constituent surface of a and 30b. The hollow molded product P is blow molded as described above.

Next, the tube 40 and nozzle 41 of the blowing means 4 are removed from the molding dies 3a and 3b. The hollow portion disposing member 42 remains in the hollow molded product P (see FIG. 4). Next, as shown in FIG. 5A, the clamp portion 32b is driven by the driving means 5 to the other clamp portion 32b.
Move to a side. As a result, the clamp portion 32b is
It moves relative to the molding part 31b. The clamp portion 32a is pushed by the clamp portion 32b and moves relatively to the molding portion 31a. Therefore, the molding material W sandwiched by the pair of clamp portions 32a and 32b.
Moves relative to the molding material W sandwiched between the (two pairs) molding portions 31a and 31b.

As a result, the molding material W sandwiched between the clamp portions 32a and 32b is shredded from the hollow molded product P held in the cavities 30a and 30b of the molding portions 31a and 31b as shown in FIG. 5 (a). To be Alternatively, they are sheared or cut and separated. By the way, the molding material W protruding from the cavities 30a and 30b forms a burr of the hollow molded product P by being clamped, and is formed on the peripheral edge of the hollow molded product P. The clamp portion 3 protrudes from the portions 31a and 31b.
The molding material W sandwiched between the 2a and 32b is removed by the relative movement of the clamp parts 32a and 32b and the molding parts 31a and 31b. In other words, a large burr is a hollow molded product P
Removed from.

Then, as shown in FIG. 6 (a), the molding portions 31a and 31b protrude from the cavities 30a and 30b.
The end surfaces 36a, 3 of the molding portions 31a, 31b do not protrude from the end surfaces 36a, 3
There is also a molding material W sandwiched by 6b. This part is
It is a portion that becomes a small burr formed along the peripheral edge of the hollow molded product P. However, when the heaters 60a and 60b of the melting means 6 are heated, the small burr portion is not heated by the heater 6a.
It is melted by the heat of 0a and 60b.

Then, a force is applied to move the molding dies 3a and 3b in the mold clamping direction even when the small burrs are melted. As a result, the molten molding material W receives a force in the compression direction, and as shown in FIG. 6B, the molten molding material W moves from between the end surfaces 36a and 36b toward the cavities 30a and 30b. As a result, the portion that becomes a small burr melts into the hollow molded product P side, and the small burr is removed. Alternatively,
As shown in FIG. 7, the small burr portion is the cavity 30.
It is melted to the opposite side of a and 30b, and small burrs are removed by this. Then, the hollow molded product P is formed into the molding dies 3a, 3b.
After cooling and solidifying inside, the molds 3a and 3b are opened as shown in FIG. 5 (b) after cooling and solidifying. As a result, the hollow molded product P is taken out (demolded) from the molding dies 3a and 3b in a state where the large burr and the small burr are removed.

The hollow molded product P is molded as described above. Therefore, the large burr of the hollow molded product P is
The small burrs are removed by the relative movement of the molding portions 31a and 31b of the molding portions 31a and 31b, and the small burr is melted and removed by the melting means 6 provided in the molding portions 31a and 31b.
As a result, such burrs formed on the hollow molded product P are easily removed by the molding dies 3a and 3b. This reduces the manufacturing cost of the hollow molded product P or shortens the manufacturing time of the hollow molded product P. The clamp parts 32a and 32b are the molding parts 31a and
Although provided along the peripheral edge of 31b, it is preferable that these gaps are small. If this gap is small, the molding material W will be the clamp parts 32, 32b and the molding parts 31a, 3b.
This is because it is easily cut by 1b and can be easily separated.

The present invention is not limited to the above embodiment, but may be in the following forms. (1) In the above-described embodiment, as shown in FIG. 2, the clamp portions 32a and 32b are configured to move relative to the molding portions 31a and 31b. It may be configured so as to move automatically. That is, the clamp portion is fixedly attached to the base portion, and the molding portion is provided so as to be able to approach and separate from the base portion. Further, this forming part is provided with means similar to the means provided for moving the clamp part of the above-mentioned embodiment, whereby the forming part moves relative to the clamp part. This also causes the molding portion to move with respect to the clamp portion, so that the portion of the hollow molded product that is to be a burr is separated from the hollow molded product. (2) In the above embodiment, the heater is provided as the melting means in both of the forming dies, but it may be provided in only one of the forming dies. (3) In the above embodiment, the technique of using Joule heat (using a heater) is used as the melting means, but the technique of melting the molding material by high frequency or the technique of melting the molding material by ultrasonic waves. May be used. When such a technique is used, a blow molding device is provided with a means for generating a high frequency wave or an ultrasonic wave instead of the heater in the above embodiment. (4) Further, in the above-described embodiment, the apparatus is used for the blow molding method such as the hot parison method or the hot sheet method in which the molding material is molded in a soft state, but the molding material does not include the extrusion means. It may be a device used for a blow molding method such as a cold parison method, in which is placed between molding dies in a cooled state and clamped in this state. (5) In the above embodiment, after removing the large burr by the relative movement of the clamp part and the forming part, the small burr is removed by the melting means. However, a method of removing the small burr and the large burr at the same time by operating the melting means at the same time as or before the relative movement of the clamp part and the forming part may be adopted. According to this, a small burr formed between the large burr and the hollow molded product becomes soft. Therefore, the large burr can be separated from the hollow molded product with a small force, and the large burr can be easily separated from the hollow molded product.

[0035]

EFFECTS OF THE INVENTION According to the technique for molding a hollow molded product according to the present invention, burrs formed around the hollow molded product can be easily treated.

[Brief description of drawings]

FIG. 1 is a perspective view of a blow molding device for a hollow molded product and a molding material.

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

3 is a cross-sectional view taken along the line BB of FIG.

FIG. 4 is a view corresponding to FIG. 2, showing a state in which a blowing unit is installed inside the molding material (a) and the molding material being clamped by a molding die, and gas is blown in that state. Including
It is the figure (b) which carried out the blow molding of the hollow molding by this.

FIG. 5 is a view corresponding to FIG. 2, showing a state in which the clamp part is moved relative to the forming part, and thereby a large burr is separated, and the forming die is opened. FIG. 6B is a diagram (b) showing a state where the hollow molded product is taken out from the molding die.

FIG. 6 is a partially enlarged view of a view corresponding to FIG. 5 (a), which shows a view before heating the heater (a) and a small size by melting the molding material by heating the heater. It is a figure (b) which shows the state which removed the burr.

FIG. 7 is a view corresponding to FIG. 6B, and FIG.
It is a figure which shows the state which removed the small burr by the state different from.

[Explanation of symbols]

1 ... Device (blow molding device) 2 ... Extrusion means 3 ... Mold clamping means 3a, 3b ... Mold 4 ... Blowing means 5 ... Driving means 6 ... Melting means 30a, 30b ... Cavity 31a, 31b ... Molding part 32a, 32b ... Clamp part 33a, 33b ... Outer frame part 34a, 34b ... Base 40 ... tube 41 ... Nozzle 42 ... Hollow part arranging member 60a, 60b ... Heater 61a, 61b ... Lead wire P ... Hollow molded product W ... Molding material

Claims (4)

[Claims] 1. A hollow molded article is blow-molded by sandwiching a molding material between a pair of molding dies, blowing gas into the molding material, and causing the molding material to follow a cavity provided in the molding die. In the blow molding apparatus, each of the pair of molding dies includes a molding portion that forms the cavity, and a clamp portion that is provided along a peripheral edge of the molding portion and that sandwiches the molding material. At least one of the molding portion and the clamp portion moves relative to the other, thereby separating the burr made of the molding material sandwiched by the clamp portion from the hollow molded article. A blow molding device for a hollow molded product, which is characterized in that 2. The blow molding apparatus according to claim 1, wherein the peripheral portion of the molding portion is provided with a melting means for melting a part of the molding material. Blow molding equipment. 3. A method for molding a hollow molded article, wherein a molding material is disposed between a pair of molding dies that are in a mold open state, and the molding material is closed by the pair of molding dies. By blowing a gas into the interior of the mold, thereby causing the molding material to follow the cavity formed in the molding part of the molding die, blow molding of the hollow molding product, or the molding part of the molding die or its molding At least one of the clamp parts that are provided along the peripheral edge of the part and that sandwich the molding material is moved relative to the other, thereby forming a burr made of the molding material that is sandwiched by the clamp parts. A method for molding a hollow molded article, which comprises separating from the molded article. 4. The method for molding a hollow molded article according to claim 3, wherein the burrs made of the molding material sandwiched by the clamps are separated from the hollow molded article or at the same time when the burrs are separated. A method for molding a hollow molded article, characterized in that a part of the molding material is melted by a melting means provided in the section.