JPH0699480A - Blow molded product fitted with flange part - Google Patents

Abstract

(57) [Summary] [Structure] A resin pipe 11 and a pair of half-split bodies 1 joined to the resin pipe 11 during blow molding of the resin pipe 11.
And a flange portion 12 composed of three. [Effect] Blow-molded product with flange 10 in which the mounting strength, surface accuracy, thickness accuracy, etc. of the flange 12 are significantly improved.
Can be manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow molded product with a flange portion.

[0002]

2. Description of the Related Art When manufacturing a blow molded product with a flange portion of this type, it is preferable to blow a disk body manufactured by injection molding or the like onto a resin pipe manufactured by blow molding to form a flange portion. It is preferable to configure the flange portion during molding because the number of steps can be reduced.

By the way, in the past, since the flange portion was integrated, only the following manufacturing technique could be adopted. That is, as the first conventional technique, a so-called vertical blow molding method is used, and as shown in FIG.
As shown in FIG. 3, the disc-shaped flange body 3 manufactured in advance by injection molding or the like is arranged at the ends of the parison 2 set in the pair of left and right split molds 1. The flange body 3
A mandrel 4 is attached to the. Then, the split mold 1 is clamped, and as shown in FIG.
The compressed air is blown into the parison 2 to shape it into a predetermined shape, and the cylinder 6 is driven to push up the mandrel 4 to insert the flange body 3. After that, Figure 2
3 (3), a blow-molded product 7 having a flange portion formed on the end portion of the resin pipe is manufactured.

A second conventional technique is Japanese Patent Laid-Open No. 63-63
There is a manufacturing method disclosed in No. 104815. That is, as shown in FIG. 24A, the parison 2 is supplied with the split mold 1 open. At this time, the mandrel 4 is arranged at the end of the parison 2 and pushes up the mandrel 4 in the direction opposite to the parison supply direction during blow molding. As a result, as shown in FIG. 24 (2), the end of the parison 2 is pressed and the flange 8 is formed at the end of the resin pipe.

[0005]

By the way, the flange portion of the blow-molded product with the flange portion is a portion which is connected to other parts by, for example, bolt and nut fastening or the like. Therefore, as a connecting portion, Structural strength is required, surface accuracy of the flange and thickness accuracy are required,
This is the part where sufficient reliability is required. Therefore, in view of such requirements, the above-mentioned conventional techniques have the following problems.

In the first prior art, a parison protrusion H (see FIG. 23 (3)) during blow molding and a flesh accumulation F (see FIG. 23 (3)) on the inner surface of the resin pipe are easily formed, which is a product. Unreliable. In addition, by using a pair of upper and lower split molds, after loading the parison into the lower split mold, clamping the upper and lower split molds and injecting air into the parison, in the so-called horizontal blow molding method. , The above-mentioned first technique cannot be used. Further, in the second conventional technique, there is a problem in the surface accuracy and the thickness accuracy of the flange portion, and air pockets may be formed inside the flange where the parison is folded, so that the strength remains uncertain. Further, both the first and second conventional techniques have a problem that the flange portion can be formed only at the end portion of the resin pipe. An object of the present invention is to provide a blow-molded product with a flange that solves all the above problems.

[0007]

In order to achieve the above object, a feature of the present invention is that a resin pipe and a flange portion formed of a pair of half-split bodies joined to the resin pipe during blow molding are provided. There is a point to have. In addition, the half-split body and the resin pipe may be combined by concavo-convex fitting. Further, the half-split body and the resin pipe may be joined by welding.

[0008]

According to the present invention, a pair of half-split bodies are set on the inner walls of a pair of split molds, and then a parison is supplied into the split molds.
After the mold is clamped, air is blown into the parison to shape it into a predetermined shape, and the parison and the half-split body are united.
As a result, it is possible to manufacture a blow molded product with a flange portion in which the mounting strength, surface accuracy, thickness accuracy, etc. of the flange portion are significantly improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of an essential part of a first embodiment of a blow molded product with a flange portion according to the present invention, and FIG. 2 is A of FIG.
FIG. The blow molded product with flange 10
It is composed of a hollow resin pipe 11 and a disc-shaped flange portion 12 fixed to an intermediate portion of the resin pipe 11. The flange portion 12 is composed of a pair of half-split bodies 13, and the half-split bodies 13 are fixed to each other by fastening bolts 14.

On the inner peripheral surface of each half-split body 13, there is formed a fitting convex portion 15 protruding inward in the radial direction along the inner peripheral surface, and the fitting convex portion 15 is formed on the resin pipe 11. It is fitted in the formed fitting recess 16. In addition, in this fitting portion, the half-split body 13 and the resin pipe 11 may be welded to each other. In this case, the flange portion 12 and the resin pipe 11 are welded and mechanically bonded to each other. It can be more firmly fixed.

FIG. 3 is a diagram showing a manufacturing process of the blow-molded product 10 with a flange portion. A concave groove 21 for accommodating the pair of half-split bodies 13 is formed in advance on each inner wall of the pair of left and right split molds 20. Each half-split body 13 is manufactured in advance by injection molding or the like. First, prior to blow molding, as shown in FIG. 3 (1), a pair of split molds 2 is used.
In the state where 0 is opened, each half-split body 13 is inserted into each groove 21
Set to. Then, the parison 22 is hung between the pair of split molds 20. At this time, the lower end of the parison 22 is sandwiched by parison pinches to form a bag portion 22a, and air is injected by pre-blowing inside the bag portion 22a.

Next, as shown in FIG. 3B, the pair of split molds 20 are clamped to pinch the upper end of the parison 22. Then, the air blowing nozzle 23 is driven from the lower end of the parison 22 to inject compressed air into the parison 22 to shape the parison 22 into a predetermined shape. At this time, the parison 22 is in a state in which the fitting convex portion 15 is rolled up. Therefore, the parison 22 and each half-split body 13 are fitted into each other by concavo-convex fitting. Then, after shaping the predetermined shape, the molded product is cooled to complete the molding. Next, the mold is opened, the molded product is taken out from the split mold 20, the half-split bodies 13 are fixed to each other by the bolts 14, and both ends of the molded product are cut to obtain a blow molded product 10 with a flange portion.

In this way, the half-split body 13 is attached to the split mold 2.
By setting to 0 and performing blow molding, it is possible to prevent the protrusion of the parison 22 and the accumulation of meat on the inner surface of the resin pipe 11. Also, the flange portion 12
Since it is composed of the half-split body 13 manufactured in advance, the surface accuracy and the thickness accuracy can be made high. Further, since the flange portion 12 is configured at the time of blow molding, as compared with the case of forming the flange portion by welding the disc body manufactured by injection molding to the resin pipe manufactured by blow molding, Can be reduced. Furthermore, by changing the formation position of the concave groove 21 in the split mold 20, it is possible to manufacture a blow-molded product having a flange portion at any position of the end portion and the intermediate portion of the resin pipe.

FIG. 4 is a sectional view of the essential parts of a second embodiment of a blow molded product with a flange portion according to the present invention, and FIG.
It is a -B sectional view. The blow-molded product 30 with a flange portion of the second embodiment is provided with a flange portion 12 composed of a pair of half-split bodies 31 at the end portion of the resin pipe 11. Then, each half-split body 31 and the resin pipe 11 are fixedly fitted and recessed by the fitting projection 15 and the fitting recess 16 in the same manner as in the blow-molded product with flange portion 10 of the first embodiment. There is. In particular, it should be noted that although the half-split body 13 of the first embodiment is fixed by bolting, the half-split body 31 of the second embodiment is fixed by the engaging means. That is, one of the half-split bodies 31 (the half-split body on the lower side in FIG. 5) has the engaging protrusions 32 formed on both ends of the outer peripheral surface, and the other half of the half-split body 31 (the upper half of the half-split body in FIG. Engaging pieces 34 having engaging concave portions 33 are formed at both ends of the outer peripheral surface of the half dividing body 31. The two are engaged and fixed to each other.

The method for manufacturing the blow-molded product 30 with the flange portion having such a structure is almost the same as that of the blow-molded product 10 with the flange portion of the first embodiment. However, although the semi-cracked bodies were fixed to each other after the blow molding in the first embodiment, in the second embodiment, when the split mold 20 is clamped,
The engaging convex portion 32 is engaged and fixed to the engaging concave portion 33. Therefore, in addition to the effects of the first embodiment, the second embodiment does not require a special process for fixing the half-split bodies 31 to each other, and has the effect that the number of processes can be reduced. There is.

6 to 10 show the construction of a third embodiment of the blow-molded product with a flange portion according to the present invention. FIG. 6 is a cross-sectional view of a main part of a blow molded product with a flange portion. A blow molded product 40 with a flange portion of the third embodiment has a flange portion 12 composed of a pair of half-split bodies 41 and a resin pipe 11. The half-split body 41 and the resin pipe 11 are fitted and fixed to each other. That is, as shown in FIGS. 7 and 8, a fitting recess 52 is formed along the circumferential direction on the inner peripheral surface of each half-split body 41, and the fitting protrusion 51 is formed on the resin pipe 11. The fitting convex portion 51 is fitted into the fitting concave portion 52 and is fitted into the concave and convex portions.

Further, as shown in FIG. 9, a pair of engaging pieces 43 are provided at one end (upper end in FIG. 7) of each half-split body 41.
Are formed so as to project at intervals in the thickness direction of the half-split bodies 41, and the other end portion (lower end portion in FIG. 7) of each half-split body 41 has the above-mentioned engagement as shown in FIG. A pair of engagement pieces 44 engageable with the piece 43 are formed so as to project in the thickness direction of the half-split body 41 at intervals. Then, the engaging piece 43 of the one half-split body 41 and the engaging piece 4 of the other half-split body 41.
4 and the engaging piece 44 of the one half-split body 41 and the engaging piece 43 of the other half-split body 41 are engaged, and the half-split body 41 is engaged.
The two are stuck together.

The blow-molded product with a flange portion 40 of the third embodiment having such a structure has the same effects as those of the blow-molded products with a flange portion 10 and 30 of the first and second embodiments, and also the flange portion. A pair of half-split bodies 41 constituting 12
Since they are the same product, there is an effect that production management is easy.

FIG. 11 is a diagram showing a manufacturing process of the blow molded product 40 with a flange portion. Blow molded product with flange 4
The manufacturing method of No. 0 is almost the same as that of the blow-molded products 10 and 30 with flange portions of the first and second embodiments. That is, the concave grooves 21 for accommodating the pair of half-split bodies 41 are formed in advance on the inner walls of the pair of left and right split molds 20, respectively. First, prior to blow molding, as shown in FIG. 11 (1), with the pair of split molds 20 opened, the half-split bodies 41 face each other and the engaging pieces 43 and 44 engage each other. In this way, each groove 21 is set. Then, the parison 22 is hung between the pair of split molds 20. At this time, the lower end of the parison 22 is sandwiched by parison pinches to form a bag portion 22a, and air is injected by pre-blowing inside the bag portion 22a.

Next, the pair of split molds 20 are clamped to pinch the upper end of the parison 22. At this time, the engagement piece 43 of the one half-split body 41 and the engagement piece 44 of the other half-split body 41 are pushed into each other while being elastically deformed in the vertical direction, and both engagement portions are brought into the engaged state. Then, the engaging piece 44 of the one half-split body 41 and the engaging piece 43 of the other half-split body 41 are pushed into each other while elastically deforming in the vertical direction, and the two engagements are brought into the engaged state. Thus, the half-cracked body 41 can be pressed with one touch when clamping the mold.
They are engaged with each other and fixed. After the mold is clamped, the air blowing nozzle 23 is driven from the lower end of the parison 22 and compressed air is injected into the parison 22 to shape the parison 22 into a predetermined shape. At this time, parison 22
However, as shown in FIG. 11 (2), it is in a state of being fitted into the fitting recess 52. Therefore, the parison 22 and each half-split body 41 are fitted into each other by concavo-convex fitting. Then, after shaping the predetermined shape, the molded product is cooled to complete the molding. Next, the mold is opened, the molded product is taken out from the split mold 20, both ends of the molded product are cut, and a blow molded product 40 with a flange portion is obtained.

Instead of the engaging pieces 43, 44, a fitting protrusion is formed at one end of each half-split body 41, and a fitting recess is formed at the other end of each half-split body 41. The so-called concavo-convex fit in which the fitting convex part of (1) and the fitting concave part of the other half-cracked body are fitted together, and the fitting concave part of one half-cracked body is fitted with the fitting convex part of the other half-cracked body Depending on the combination, the half-split bodies may be fixed to each other. 12 to 17 show a fourth embodiment of the blow-molded product with a flange portion according to the present invention. The blow-molded product 60 with a flange portion is a resin pipe 1 having a substantially U shape.
1 and flange portions 12 provided on the upper portions of both ends of the resin pipe 11.

The flange portion 12 comprises a pair of half-split bodies 61 obtained by dividing the flange portion 12 into two in the width direction. A fitting convex portion 15 protruding inward is formed on a portion of the inner surface of each of the half-split bodies 61 excluding both ends in the longitudinal direction.
Portions of the fitting protrusion 15 excluding both ends in the longitudinal direction and the central portion in the longitudinal direction are fitted into the fitting recess 16 formed in the resin pipe 11 in a concavo-convex manner. A pair of upper and lower fin portions 64 protruding outward are formed on the outer surface of each half-split body 61 over the entire length. Also, both half-split bodies 6
Reference numeral 1 denotes both longitudinal end portions and a longitudinal central portion, which are separated from each other, and the respective gaps between them are filled with burrs 62 generated during blow molding of the resin pipe 11, so that both half-split bodies 6 are formed.
The both ends in the longitudinal direction and the central portion in the longitudinal direction of the fitting convex portion 15 of No. 1 are concave and convex in the fitting concave portion 63 formed in the burr portion 62.

The resin pipe 11 and the burr portion 62 may be welded to each half-split body 61. By welding, the flange portion 12 can be more firmly fixed to the resin pipe 11. FIG. 17 shows a manufacturing process of a blow molded product with a flange portion 60. Prior to blow molding, a pair of left and right split molds 20 as shown in FIG. Each half-split body 61 is set in each groove 21. Next, between the pair of split molds 20, the parison 22 having a lower end portion welded by cutting and formed into a bag shape is hung down. At this time,
Pre-blow is applied to the inside of the parison 22 to inject air.

Next, after clamping the pair of split molds 20,
Compressed air is injected into the parison 22 from the upper end of the parison 22 to shape the parison 22 into a predetermined shape, and U
The resin pipe 11 is shaped like a letter. At this time, parison 22
Is in a state in which the fitting convex portion 15 is rolled up, and the resin pipe 11 has a fitting concave portion 16 that is fitted into the fitting convex portion 15 in a concavo-convex manner.
Is formed. In addition, in the above case, burrs are formed between the split molds 20. The burrs enter the gap between the half-split bodies 61 to form the burr portion 62 for filling the gap, and at the same time, form the burr portion. 62 is in a state in which the fitting convex portion 15 is rolled up, and the burr portion 62 is formed with a fitting concave portion 63 that is fitted into the fitting convex portion 15 in a concavo-convex manner. Therefore, the parison 22 and each half-split body 13 are fitted into each other by concavo-convex fitting.

After forming a predetermined shape, the molded product is cooled to complete the molding. Then, open the mold and split mold 2
A blow molded product with a flange portion 60 is obtained by taking out a molded product from 0 and cutting the upper end thereof. FIG.
Shows a fifth embodiment of the blow-molded product with a flange portion according to the present invention, and has a configuration similar to that of the fourth embodiment, but one end portion in the longitudinal direction of the pair of half-split bodies 61 constituting the flange portion 12. Are in contact. In addition, both ends in the longitudinal direction of the pair of half-split bodies 61 and any part of the central part in the longitudinal direction may be brought into contact with each other, or two or all of the above parts may be brought into contact with each other. You may let me.

19 and 20 show a sixth embodiment of the blow-molded product with a flange portion according to the present invention, which is a modification of the fourth embodiment. In the fourth embodiment, the resin pipe 11 is U-shaped. In contrast to the letter shape, in the blow molded product with flange 70 of the sixth embodiment, the resin pipe 11 is linear. At the upper part of the resin pipe 11, a pair of half-split bodies 71
A disk-shaped flange portion 12 made of is fixed. A fitting convex portion 15 is formed on the inner side surface of the half-split body 71 as in the fourth embodiment, and is provided in the resin pipe 11 in substantially the same manner as in the fourth embodiment.

21 and 22 show a seventh embodiment of the blow-molded product with a flange portion according to the present invention. In the blow-molded product 80 with a flange portion of the seventh embodiment, the resin pipe 11 is used.
Is in the shape of a rectangular tube, and the flange portion 12 is externally fitted and fixed to the end portion thereof. The flange portion 12 includes a pair of half-split bodies 81.
Each of the half-split bodies 81 includes a bow-shaped vertical wall portion 82 provided along one side of the lower end portion of the resin pipe 11, and a horizontal wall portion horizontally projected from the lower end portion of the vertical wall portion 82. And 83. The vertical wall portions 82 of the two half-split bodies 51 are butted to each other to form a rectangular tube, which is fitted onto the resin pipe 11. Further, the horizontal wall portions 83 of the two half-split bodies 51 are also abutted to each other to form a substantially square frame shape. A pair of projecting portions 84 projecting outward in the radial direction are formed at both ends of the vertical wall portion 82, and each projecting portion 84 of each vertical wall portion 82 corresponds to each projecting portion of the other vertical wall portion 82. 84 and the lower portion are abutted with each other, and a burr portion 85 is filled between the upper portions of the both protruding portions 84 that are abutted,
Both protrusions 84 are welded by the burr 85.

[0028]

As described above, according to the present invention, a pair of half-split bodies that are united with a resin pipe during blow molding,
Since the flange portion is configured, it is possible to set a half-cracked body on the inner wall of the split mold and perform blow molding. As a result, the parison is squeezed out in the first prior art and the flesh is accumulated on the inner surface of the resin pipe. It is possible to solve the problem that occurs. Further, since the half-cracked body can be manufactured in advance, the surface accuracy and the thickness accuracy of the flange portion in the second conventional technique are deteriorated, and the parison is folded to form an air pocket inside the flange, so that the flange portion can be mounted. The problem of reduced strength can be solved.

Further, in the first and second prior arts, the flange portion can be formed only at the end portion of the resin pipe, but according to the present invention, any end portion or intermediate portion of the resin pipe can be formed. A flange portion can be formed at the position. Further, according to the present invention, not only the so-called vertical blow molding method but also the horizontal blow molding method can be used.

[Brief description of drawings]

FIG. 1 is a first blow-molded product with a flange portion according to the present invention.
It is an important section sectional view of an example.

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

FIG. 3 is a first blow-molded product with a flange portion according to the present invention.
It is a figure which shows the manufacturing process of an Example.

FIG. 4 is a second blow-molded product with a flange portion according to the present invention.
It is an important section sectional view of an example.

5 is a sectional view taken along the line BB of FIG.

FIG. 6 is a third blow-molded product with a flange portion according to the present invention.
It is an important section sectional view of an example.

FIG. 7 is a third blow-molded product with a flange portion according to the present invention.
It is a top view of the half cracked body which constitutes the flange part of an example.

8 is a sectional view taken along the line CC of FIG.

9 is a view seen from the arrow D side of FIG. 7.

10 is a view seen from the arrow E side of FIG.

FIG. 11 is a diagram showing a manufacturing process of a third embodiment of the blow-molded product with a flange portion according to the present invention.

FIG. 12 is a front view of a fourth embodiment of a blow molded product with a flange portion according to the present invention.

13 is a sectional view taken along the line FF of FIG.

14 is a sectional view taken along the line GG in FIG.

15 is a cross-sectional view taken along the line HH of FIG.

16 is a view of the half-split body of FIG. 13 taken along the line JJ.

FIG. 17 is a view showing a manufacturing process of the fourth example of the blow-molded product with the flange portion according to the present invention.

FIG. 18 is a cross-sectional view of essential parts of a fifth embodiment of the blow-molded product with a flange portion according to the present invention.

FIG. 19 is a front view of the essential parts of a sixth embodiment of a blow-molded product with a flange according to the present invention.

20 is a sectional view taken along the line KK of FIG.

FIG. 21 is a partial front view of a blow molded product with a flange according to the present invention, showing a partial cross section of a seventh embodiment.

22 is a sectional view taken along the line LL in FIG.

FIG. 23 is a diagram showing a manufacturing process of a first conventional technique.

FIG. 24 is a diagram showing a manufacturing process of a second conventional technique.

[Explanation of symbols]

10, 30, 40, 60, 70, 80 ... Blow molded products,
11 ... Resin pipe, 12 ... Flange portion, 13, 31, 4
1, 61, 71, 81 ... Half-split body, 15, 51 ... Fitting convex part, 16, 52, 63 ... Fitting concave part, 20 ... Split mold, 22
… Parison, 62… Bali section.

Claims (3)

[Claims] 1. A blow-molded article with a flange portion, comprising a resin pipe and a flange portion formed of a pair of half-split bodies joined to the resin pipe during blow molding. 2. A blow-molded article with a flange portion according to claim 1, wherein the half-split body and the resin pipe are united by a concave-convex fit. 3. The blow molded product with a flange portion according to claim 1, wherein the half-split body and the resin pipe are united by welding.