JPH074025U - Burrless blow mold - Google Patents

Abstract

(57) [Summary] [Purpose] The appearance quality is improved by eliminating the occurrence of burrs and the absence of burr finishing marks, simplification of the production process by reducing the burr excision process, and the associated reduction in production costs. The purpose is to prevent punctures. [Structure] Forming molding surfaces 11 and 13 on the inner side surfaces of the pair of molds 3 and 4 corresponding to the outer surface of the molded product, and a parison is interposed between these molds to press the molds 3 and 4 together. In a blow-molding die to be molded by molding, one of the above-mentioned molds is divided into a part corresponding to a side surface part of a molded product, and a center part 4a and molds 3 and 4 are opened and closed with respect to the center part. Sliding part 4b that slides
・ 4b is formed, and during molding, sliding parts 4b and 4b contact the other mold 3 earlier than the extension of the parison between the molds 3 and 4 to complete the mold sealing, and the center part is displaced with a time difference and slides. Part 4b
-Align with 4b and mold the parison.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a burr-free blow molding die used in the field of blow molding using a soft synthetic resin as a material.

[0002]

[Prior art]

 Conventionally, when a flat product is blow-molded using a soft synthetic resin as a material, as shown in FIG. 4, a pair of opposed molds (a) and (a) are moved by a hydraulic cylinder (b) (b). It is configured so that it can be worked, and the matte finish / texture is processed and polished on the concave surface (c) (c) that matches the outer shape of the product to be molded on the inner surface of the mold (a) (a). Finishing, between these molds (a) and (a), a certain amount of gas is blown into the material to form a bag-shaped parison (d), and the molds (a) and (a) are placed in a hydraulic cylinder. The molds (a) and (a) were pressed against each other by (b) and (b) to form a parison (d). In the conventional molding of flat-shaped products, if the edge portion is shaped only by stretching, the product will be extremely thin or will burst. Then, the side part of the parison (d) is protruded from the peripheral part (e) (e) of the mold (a) (a), that is, the product molding part, so-called burr (f) (f). And the burr formation was performed using only the thick parts.

[0003]

[Problems to be solved by the device]

 At the same time, the conventional total burr molding requires a finishing process to cut off the burr (f) (f) over the entire circumference of the parison (d), which lowers the appearance quality and makes the appearance parts look good. In the case of the products, the drawbacks were that the surface from which the burr was cut appeared, that the width of the cut surface was uneven, and that the surface from which the burr was cut had no wrinkles.

The present invention eliminates the occurrence of burrs during blow molding of a parison, improves the appearance quality due to the absence of burr finishing marks, simplifies the production process by reducing the burr excision process, and the associated production cost. This is a device for the purpose of reduction and prevention of puncture of parison.

[0005]

[Means for Solving the Problems]

 According to the present invention, a molding surface 11.13 is formed on the inner surface of each of the pair of molds 3, 4 corresponding to the outer surface of the molded product, and a parison (d) is interposed between these molds 3, 4. In a blow molding die in which the molds 3 and 4 are pressed against each other and molded, one of the molds 3 and 4 is divided into a part corresponding to the side surface part of the molded product, and the central part 4a and this central part are formed. Sliding parts 4b and 4b that slide in the direction in which the molds 3 and 4 open and close are formed with respect to the part 4a, and during molding, the sliding parts 4b and 4b move faster than the extension of the parison (d) between the molds 3 and 4. The mold sealing is completed by contacting the other mold 3, and the central portion 4a is displaced with a time difference and aligned with the sliding portions 4b and 4b to form a parison (d).

[0006]

【Example】

 1, 2 and 3 show the steps of blow molding with the mold of the present invention, and 1.2 are hydraulic cylinders for advancing and retracting the left and right molds 3 and 4 of these molds. The tips of the plurality of rods 5, 5, 6, 6 coming in and out of 1.2 are fixed to the board 7.8, and the mold 3 is attached to the board 7.8 via the legs 9, 9, 10, 10.・ Fix 4.

Then, in FIG. 1, the inner surface of the right mold 3 is formed into a molding surface 11 conforming to the outer surface of the product to be molded, and the protrusions 12 and 12 are formed at the side edge portions of the molding 11. .

Further, in FIG. 1, the left mold 4 is divided into three parts, the central part 4a is fixed to the board 8 through the legs 10 and 10, and the inner surface is the outer surface of the product to be molded. Form a conforming molding surface 13.

Further, sliding portions 4b, 4b are provided on the side portions of the central portion 4a so as to slide adjacent to each other in an airtight manner. Protruding portions 4c and 4c which are in airtight contact with the protruding portions 12 and 12 when the mold is closed are formed at the front ends of the sliding portions 4b and 4b, and a long hole 4d for guiding in the sliding direction is formed. 4d are provided, springs 14 and 14d are fitted in these long holes 4d and 4d, and the tip of the guide rods 15 and 15 fixed to the board 8 are fitted to the sliding portions 4b and 4b. The tip portion is configured to have a positional relationship in which it projects from the molding surface 13 of the central portion 4a.

In the embodiment, one mold 4 of the mold is divided into three parts, but the other mold 3 is also divided into three parts, and the central part is connected to the board through the legs. In some cases, the fixed portion and the sliding portion may be slidably fitted to a guide rod having a spring fitted therein, and may have a structure similar to that of the embodiment. Also, one or both of the molds may be divided into two parts.

[0011]

[Function of the device]

 Since the present invention is configured as described above, when the hydraulic cylinders 1 and 2 are operated with the parison (d) interposed between the molds 3 and 4, the rods 5, 5, 6 and 6 are moved forward. As a result, the molds 3 and 4 move forward together with the board plates 7 and 8. As the mold 3 on the right side advances, one outer surface of the parison (d) is gradually joined to the molding surface 11 and is attached to the molding surface 11.

The sliding portion 4b of the left mold 4 projects from the molding surface 13 of the central portion 4a which is pressed by the elastic force of the springs 14 and 14 and fixed to the board 8 via the legs 10. Because of the presence, the central portion 4a is in a positional relationship in which it is retracted from the sliding portions 4b and 4b, and the concave portion 16 is formed. Therefore, as shown in FIG. 2, only a part of the parison (d) is bonded to the molding surface 13.

As the rod 6 of the hydraulic cylinder 2 further projects, the die 4 also moves forward together with the board 8, and the protrusions 4c and 4c of the sliding portions 4b and 4b come into contact with the protrusions 12 and 12 of the right die 3. . Further, when the rods 6 and 6 are projected, the sliding portions 4b and 4b do not move because the protrusions 4c and 4c are in contact with the protrusions 12 and 12 of the right die 3, and the sliding portions 4b and 4b move together with the board plate 8 and the guide rod 1. Since 5 and 15 move forward, they move in the long holes 4d and 4d of the sliding portions 4b and 4b, the springs 14 and 14 are compressed, and the sliding portions 4b and 4b retract with respect to the central portion 4a. Due to the positional relationship, the outer surface of the parison (d) contacts the front surface of the molding surface 13 of the central portion 4a, and when the springs 14 and 14 have finished contracting, the central portion 4a and the sliding portions 4b and 4b are aligned. However, the parison (d) is attached to the flat shape to be formed.

After the parison (d) is hardened, when the hydraulic cylinders 1 and 2 are operated to retract the rods 5, 5, 6, and 6, the left and right board plates 7 and 8 and the right mold 3 are also retracted. At this time, in the left mold 4, the central portion 4a and the guide rods 15 and 15 start to retreat together with the board plate 8, but the protrusions 4c and 4c remain in the right mold 3 until the springs 14 and 14 are restored by elasticity. When the sling 14 has reached the state where it has finished extending, it begins to separate from the protrusion 12/12 of the right mold 3 and the guide rod 15/15 slides on the sliding portion 4b. The positional relationship of retreating inside the long holes 4d and 4d of 4b creates a space within the long holes 4d and 4d, and the release of the parison (d) is completed.

[0015]

[Effect of device]

 Therefore, according to the present invention, one of the molds is divided into three parts, and the central part and the sliding part projecting and slidable from the central part first come into contact with the projecting part of the other mold. It is possible to mold the side surface of the product without burrs without closing the molding of the parison and restricting the parison stretching to limit the molding surface of the mold to cause burrs. Further, the appearance quality is remarkably improved without the unevenness of the burr cut surface. Moreover, the production cost can be reduced by eliminating the need for the burr finishing process for the molded product.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view when a blow molding is started by inserting a parison into a flat-shaped product molding die of the present invention.

FIG. 2 is a cross-sectional plan view showing a state in which left and right molds are moved forward and a movable part of one mold is slid to perform blow molding.

FIG. 3 is a cross-sectional plan view showing a state where the mold of the present invention is completely closed.

FIG. 4 is a front view of a conventional die for molding a flat product.

5 is a cross-sectional plan view taken along the line AA of FIG. 4, showing a state in which a parison is interposed between molds and blow molding is started.

FIG. 6 is a cross-sectional plan view showing a state in which a conventional mold is closed and burrs are generated.

[Explanation of symbols] 1.2 hydraulic cylinder 4b / 4b sliding part 3 type 4c / 4c protrusion 4 type 5/5/6/6 rod 4a central part 7.8 plate 9/9/10/10 legs ( Reference number of conventional example) 11 molding surface ai die 12 projecting part ro ro hydraulic cylinder 13 molding surface ha ha concave surface 14 14 spring niparison 15 15 guide rod ho ho peripheral portion 16 concave portion hebery

Claims (1)

[Scope of utility model registration request] 1. A molding surface 11.13 corresponding to the outer surface of a molded product is formed on the inner surface of each of the pair of molds 3, 4, and a parison (d) is interposed between these molds 3, 4. Wearing a mold 3.4
In a blow-molding mold for press-bonding each other, one of the molds 3 and 4 is divided into parts corresponding to the side surfaces of the molded product, and a mold is formed for the central portion 4a and the central portion 4a. 3.4
Form sliding parts 4b, 4b that slide in the opening and closing directions,
During molding, the sliding parts 4b, 4b contact the other mold 3 earlier than the extension of the parison (d) between the molds 3, 4 to complete the mold sealing, and the central part 4a is displaced with a time difference to cause sliding parts 4b.・ 4
A burr-free blow molding die characterized by being aligned with b and molding a parison (d).