JPH0739132B2 - Blow molded product with flange and manufacturing method thereof - Google Patents

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 and a method for manufacturing the same.

[0002]

2. Description of the Related Art When manufacturing a blow-molded product with a flange portion of this kind, it is better to blow a disc body manufactured by injection molding or the like to 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.

Therefore, conventionally, the following first or second technique is used. 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. Then, Figure 1
As shown in 2 (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. 13 (1), 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. 13B, 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. 12 (3)) during blow molding and a flesh accumulation F (see FIG. 12 (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, a so-called horizontal blow molding method is used. , 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 and a method for manufacturing the same, which solves all the above problems.

[0007]

In order to achieve the above object, the method of manufacturing a blow molded product with a flange portion according to the present invention is characterized in that the inner wall of each of the split molds has a circumferential direction. Regarding, set the half cracked body that constitutes half of the flange part, then set the parison between both split molds, clamp both split molds, join the half cracked bodies, and then The point is that air is blown into the parison to shape the parison into a predetermined shape, and the parison and the half-split body are united.

Further, in the method for manufacturing a blow molded article with a flange portion according to the present invention, half cracked bodies constituting half of the flange portion in the circumferential direction are set on the inner walls of each of the split molds, and then, After setting the parison between the two molds,
It is also possible to clamp both split molds, then blow air into the parison to shape the parison into a predetermined shape, combine the parison and the half-cracked body, and then join the half-cracked bodies together. is there.

In order to achieve the above object, the blow molded article with a flange portion according to the present invention is characterized in that it has a resin pipe and a flange portion composed of a pair of half-split bodies joined to the resin pipe. However, each half-split body constitutes half of the flange portion in the circumferential direction, and the half-split bodies are joined together. In addition, the half-split body and the resin pipe may be joined together by concave and convex fitting. Further, the half-split body and the resin pipe may be joined by welding. Further, the half-split bodies may be joined together by bolting. Further, the half-split bodies may be joined together by the engaging means. Furthermore, the half-split bodies may be joined together by concave and convex fitting.

[0010]

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.
The mold is clamped to join the half-split bodies together, and then air is blown into the parison to shape it into a predetermined shape, and the parison and the half-split bodies are joined together. 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.

[0011]

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.
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. Each half-split body 13 constitutes half of the flange portion 12 in the circumferential direction, 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 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 view 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 a disc body manufactured by injection molding or the like to a 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. 5). 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 flange 40 of the third embodiment having such a structure has the same effect as the blow molded products with flange 10 and 30 of the first and second embodiments, and the flange 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 view 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. Incidentally, 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, so that the fitting projection of one half-split body and the fitting recess of the other half-split body are formed. May be fitted to each other, and the fitting concave portions of one half-cracked body and the fitting convex portions of the other half-cracked body may be fitted together, so that the half-cracked bodies may be fixed to each other by so-called concavo-convex fitting.

[0023]

As described above, according to the present invention, since the flange portion is constituted by the pair of half-cracked bodies, the half-cracked bodies can be set on the inner wall of the split mold and blow molding can be performed. As a result, it is possible to solve the problems of the protrusion of the parison and the accumulation of meat on the inner surface of the resin pipe in the first conventional technique. In addition, since the half-cracked body is manufactured in advance, the surface accuracy and thickness accuracy of the flange portion in the second conventional technique is deteriorated, and the parison is folded to form an air pocket inside the flange, so that the flange portion is attached. The problem of reduced strength can be solved.

Further, in the first and second conventional techniques, 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 diagram showing a manufacturing process of a first conventional technique.

FIG. 13 is a diagram showing a manufacturing process of a second conventional technique.

[Explanation of symbols]

10, 30, 40 ... Blow-molded products, 11 ... Resin pipes,
12 ... Flange portion, 13, 31, 41 ... Half-cracked body, 20
… Split mold, 22… Parison.

Claims (8)

[Claims] 1. A pair of split mold inner walls are each provided with a half-cracked body that constitutes half of the flange portion in the circumferential direction. Next, a parison is set between the split molds, and then both split molds are set. Clamp the mold, combine the half-split bodies together, then
A method for producing a blow-molded article with a flange, comprising blowing air into the parison to shape the parison into a predetermined shape and uniting the parison and the half-cracked body. 2. A pair of split mold inner walls are each set with a half-cracked body that constitutes half of the flange portion in the circumferential direction, and then a parison is set between both split molds, and then both split molds are split. The mold is clamped, then air is blown into the parison to shape the parison into a predetermined shape, the parison and the half-cracked body are united, and then the half-cracked body is united. Method for manufacturing blow molded product with flange. 3. A resin pipe and a flange portion formed of a pair of half-split bodies joined to the resin pipe, each half-split body constituting half of the flange portion in the circumferential direction, and the half-split portion. A blow molded product with a flange, characterized in that the bodies are joined together. 4. A blow-molded article with a flange portion according to claim 3, wherein the half-split body and the resin pipe are united by means of concavo-convex fitting. 5. The blow molded product with a flange portion according to claim 3, wherein the half-split body and the resin pipe are united by welding. 6. A blow-molded article with a flange portion according to claim 3, wherein the half-split bodies are joined together by bolting. 7. A blow-molded article with a flange portion according to claim 3, wherein the half-split bodies are united by an engaging means. 8. The blow-molded article with a flange portion according to claim 3, wherein the half-split bodies are united by concavo-convex fitting.