JPS62156924A - Molding method of bent hollow body - Google Patents

Abstract

PURPOSE:To improve yield by enabling use of a miniature extrusion machine and decreasing burrs, by holding a parison between cavities whose intermediate part is bent sideward with respect to both end parts by making the parison follow after forms of the cavities. CONSTITUTION:A parison 5 is suspended between a right and left split molds 1, 2 which are under a broken state along both end parts of cavities 3, 4 and the lower end of the parison is fixed with a fixing device 6. Then intermediate members 1c, 2c are moved along a parting line, only both the intermediate members 1c, 2c are clamped by facing cavity parts of the intermediate members 1c, 2c to the parison 5 and the parison 5 is held between the cavity parts. Then both the intermediate members 1c, 2c are moved up to the original position wherein forms of the cavities 3, 4 of both the split molds 1, 2 are coincident with each other. then the parison 5 is closed up tightly by clamping a right and left and upper and lower members 1a, 1b, 2a, 2b and blow molding is performed by introducing a pressure fluid within the parison 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for molding a hollow body, particularly a hollow body having a shape in which the middle part is bent laterally with respect to both ends.

2. Description of the Related Art The above-mentioned hollow bodies having a shape bent laterally at the middle part include armrests, headrests, covers for handles used as interior parts of automobiles, ducts and pipes of electrical appliances, various tool covers, and medical equipment. be.

The seventh quotient shows an example of the armrest α, which is bent laterally with respect to its middle portion or both ends. When hollow molding an armrest α having such a shape, conventionally the armrest α is formed as shown in FIGS. A parison f having a thickness sufficient to cover the entire width W of both cavities b and c is placed between the cavities b and c, and molding is performed by clamping the mold.

Problems to be Solved by the Invention The conventional molding method described above requires a parison f that is slightly thicker than the full width of the cavities b and c, which requires a large extruder, and also requires a large extruder. As it grew larger, it became uneconomical because it had to be divided into parts.

Means and Effects for Solving the Problems The present invention has been made in view of the above-mentioned problems.The present invention has been made in view of the above-mentioned problems. A method for forming a bent hollow body that can be formed into dimensions that are approximately the same as the width, that allows the use of a small extruder, and that can be formed economically with less flaking and easy walking. The purpose of this molding method is to use a left and right split mold having a cavity in which the middle part is bent to one side with respect to both ends. Divide and place the middle member on top.

Separately from the lower member, the mold is provided so that it can be clamped, a parison is suspended between the two split molds, and its lower end is fixed by a fixing means,
Next, the intermediate members of the left and right split molds are opposed to the parison, the molds are clamped, and the parison is held between the intermediate members, and then the intermediate members and the hanging position of the parison are set relative to each other in the bending direction of the cavity. , then up,
The lower member is mold-clamped, and by the above-described molding method, the parison is shaped roughly along the curved cavity and is held between the left and right split molds.

Embodiment An embodiment of the present invention will be explained based on FIGS. 1 to 6 for the case of molding an armrest α shown in FIG. 7.

In the figure, 1 and 2 are left and right split molds, and these two split molds 1.2
A cavity 3.4 is provided on the opposing surface of the armrest α, which is divided into two in the thickness direction. Both cavities 3
．． 4 is long in the vertical direction, and is bent toward the middle or both ends thereof.

The above two-part mold 1. 2 are upper and lower members 1a,
lb, 2G, 2b, and intermediate member 1o.

It is divided vertically into 2C and intermediate member 1't2.
' are movable in the lateral direction along the parting line with respect to the upper and lower members 1a*Ib*2''t2b.Also, the rain intermediate members 1'*2' are upper and lower members 1g,
lb, 2a.

The mold clamping operation can be performed separately from 2b.

Next, a molding method using the apparatus configured as described above will be explained.

First, the Harrison 5 is suspended between the left and right split molds 1.2 in an open state and along both ends of the cavity 3.4), and its lower end is fixed by the fixing means 6. Next, the intermediate members IC and 2C of both split molds 1.2 are moved along the parting line so that the cavity portions of the intermediate members rC and 2c are opposed to the parison 5 (Fig. 3), and then Only the rain intermediate members 1c and 2c are mold-clamped, and the parison 5 is held in the cavity portion thereof (41st step).

Next, this rain intermediate member 1? , 2C') Both split molds 1, 2
to the original position where the shapes of cavities 3 and 4 match (FIG. 5). After that, left and right upper and lower parts 1cLt
Ib+ 2CL, 2b is mold-clamped to seal the parison 5 (Fig. 6), and pressure fluid is introduced into the parison 5 for blow molding.

By the above molding method, the parison 5 is mold-clamped and sealed in a bent state along the cavities 3 and 4, and the two divided molds 1
．． There are fewer children in Paris 5 who are caught on the opposite side of 2.

In the above embodiment, the parison 5 is placed in the left and right divided molds 1.
, 2 and along both ends of the cavity 3.4 to the hanging position of the parison 5.
Move c and clamp the mold, then move intermediate members 1c and 2c to their original positions, then upper and lower members 1α+lb*2"
*2b was shown as an example in which the mold was clamped, but the Harrison 5 was suspended along the middle part of the cavities 3 and 4, this Parison 5 was held between the intermediate member I's2C, and then the split metal was The entire mold 1.2 and the hanging position of the parison 5 are placed in the cavity 3. It may be made to move relatively in the bending direction of No. 4.

In this case, the intermediate members 1c and 2c are the upper and lower members 1α.

The whole of the split mold 1.2 can be moved relative to the hanging position of the parison 5 without the need to move it in the lateral direction with respect to Ib, 2α, 2b, or conversely, the hanging position of the parison 5 can be moved to the hanging position of the parison 5. Move relative to the positions of molds 1 and 2.

It should be noted that the fixing means is not limited to the above-mentioned embodiments, and may be, for example, a fixing means installed inside the inner diameter of the lower end of the parison 5, or any other suitable means can be used. In addition, there are two types of clamping methods: one that surrounds the hanging parison 5 as in the above-mentioned example when it is smaller than the cavity of the intermediate members jc and 2c, and one that clamps it by the mold itself. .

Effects of the Invention According to the present invention, the intermediate portion is a cavity with respect to both ends, 5 is a parison, and 6 is a fixing means.

Since the parison 5 can be held in the cavities 3 and 4 that are bent in the direction along the shape thereof, the thickness of the parison 5 can be made to approximately match the actual width of the cavities 3 and 4. As a result, the thickness of the parison 5 can be made thinner than in the conventional method, and a smaller extruder can be used than in the conventional method. Further, according to the method of the present invention, left and right split molds 1.
The number of parts sandwiched between the opposing surfaces of the two is reduced, so there is less paris, resulting in better fractionation and economy.

[Brief explanation of drawings]

Figures 1 to 6 show embodiments of the present invention, with Figure 1 being a sectional view of the mold device, Figure 2 being a front view of a 10,000-piece split mold, and Figures 3 to 6 being a cross-sectional view of the mold device. is' “Explanatory Diagram of Action, No. 7
The figure is a perspective view of the armrest, FIG. 8 is a cross-sectional view of a mold device used in the conventional method, and FIG. 9 is a front view of the 10,000-split mold.

Claims (1)

[Claims] Left and right split molds 1 and 2 having cavities 3 and 4 each having a shape in which the middle part is bent to one side with respect to both ends are formed into upper and lower members 1a, 1b, 2a, 2b and intermediate members 1c and 2c. At the same time, the intermediate members 1c and 2c are divided into upper and lower members 1a and 1.
b, 2a, and 2b so that the mold can be clamped separately, a parison 5 is arranged between the two split molds 1 and 2, and its lower end is fixed by a fixing means 6, and then the left and right split molds 1, The cavity portions of the intermediate members 1c and 2c of 2 are opposed to the parison 5, and then the molds are clamped to sandwich the parison 5 between the intermediate members 1c and 2c, and then the intermediate members 1c and
2c and the arrangement position of the parison 5 are moved relative to each other in the bending direction of the cavities 3 and 4, and then the upper and lower members 1a and 1b are moved.
, 2a and 2b are clamped together.