JPH1044240A - Molding of resin tubular member having joining flange part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the lowering of seal capacity at the time of mounting of a seal member by generating no difference in level to the connection part of a seal groove when split parts are mutually joined. SOLUTION: Unopened parts 9 are preformed to the end parts on the side of split surfaces 7 of seal grooves 5a when split parts 6, 6 are molded before the split parts 6, 6 are mutually joined and integrated. Thereafter, positioning pins 15 are engaged with the respective seal grooves 5a, 5a to perform the relative positioning of the unopened parts 9 and a heat-fusion plate 11. The unopened parts 9 are melted by the heat-fusion plate 11 to smoothly continue the mutual seal grooves 5a, 5a so as not to generate large difference in level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin having a large-diameter joint flange at an end and a closed-loop-shaped seal groove formed in a portion of the joint flange to be a joint surface with a counterpart. In particular, the present invention relates to a method of forming a tubular body made of a plastic material, and particularly to a method of forming a half part having a shape obtained by dividing a tubular body including a joint flange portion by a surface crossing a seal groove of the joint flange portion, and dividing the half part into two. The present invention relates to a molding method in which a set is abutted and joined to each other.

[0002]

2. Description of the Related Art FIGS.
As shown in FIG. 5, large-diameter joint flanges 52, 53 are provided at both ends in the longitudinal direction, while the joint flanges 52, 5 are provided.
When a resin-made tubular body 51 having seal grooves 54, 55 for mounting a seal member formed therein is formed on the tubular body 3, as shown in FIG. , 55) are formed in advance, and the two halved parts 5 are formed in advance.
There is known a molding method in which 6, 6 are abutted to each other at a divided surface 57 and are joined by using an adhesion method such as vibration welding.

In this molding method, the joining flange portions 52, 5
In FIG. 3, it is inevitable that a joint line 58 is formed by a two-part structure. In particular, as shown in FIG.
Since a step 59 is generated at the connecting portion between the two and the groove width is locally reduced, as a result, even if an O-ring-shaped sealing member is to be mounted on the sealing groove 54, the sealing performance is not properly accommodated in the sealing groove 54, and the sealing performance is not improved. Is undesirably reduced.

[0004] In view of the above, in order to avoid the occurrence of the joining line 58 at the joining flange portions 52 and 53 as described above, the joining flange portion 52 is assumed as shown in FIG. , 53, a method of forming a tubular body 61 composed of two parts 62 and 63 in which a dividing surface 60 is set in a part other than the parts (for example, “Nikkei Mechanical” 199).
3, 2, 22, published by Nikkei BP, p. 41).

[0005] This structure eliminates the above-mentioned problems in terms of sealing performance, however, in order to avoid an undercut portion during molding of the part 61, the structure thereof is shown in FIGS.
The slide cores 64 and 65 shown in FIG. 1 are required, which results in an increase in the cost of the product with an increase in the mold manufacturing cost, which is not preferable.

The present invention has been made in view of the above-mentioned problems. As shown in FIGS. 10 and 11, the occurrence of a joint line at a joint flange portion is allowed, but the gap between the seal grooves is reduced. An object of the present invention is to provide a method for forming a tubular body in which the occurrence of a step is prevented beforehand and the sealing performance is improved while reducing costs.

[0007]

According to a first aspect of the present invention, a large-diameter joint flange portion is provided at an end portion, and a portion of the joint flange portion to be a joint surface with a mating side has a closed loop shape. A method of molding a resin tubular body having a seal groove formed therein, the step of molding a half-part having a shape obtained by dividing a tubular body including a joint flange portion into two along a surface crossing the seal groove of the joint flange portion. And joining the two halved parts by abutting each other at the divided surface thereof, wherein the seal groove formed at the same time as the molding of the halved part has an incomplete end on the divided surface side in advance. While being formed into a shape, after joining the halved parts, the incompletely shaped portion of the seal groove formed on both halved parts is melted and connected to each other while finishing to a regular shape. .

According to a second aspect of the present invention, in the first aspect of the present invention, the incompletely shaped portion formed in advance at the end of the seal groove is such that the end of the seal groove is not opened to the dividing surface side. And is formed by being interrupted near the dividing plane.

According to a third aspect of the present invention, in the incompletely formed portion formed in advance at the end of the seal groove in the first aspect of the invention, the end of the seal groove is opened to the dividing surface side. However, it is characterized in that it is formed by making the groove width narrower than the regular size in the vicinity of the division surface.

According to a fourth aspect of the present invention, the sealing groove according to any one of the first to third aspects, wherein the incompletely shaped portion of the seal groove is melted and finished into a regular shape, and the two are connected to each other. Is a heat welding jig having a width dimension equivalent to the groove width of the regular shape portion.

According to a fifth aspect of the present invention, there is provided a heat welding jig according to the fourth aspect of the present invention, wherein the positioning jig simultaneously engages with a regular shape portion of the seal grooves formed in both the half parts. The heat welding jig melts the incompletely shaped portion while being guided by the positioning jig.

According to a sixth aspect of the present invention, the positioning jig according to the fifth aspect of the invention is characterized in that the tip is formed in a tapered shape.

According to a seventh aspect of the present invention, the positioning jig according to the sixth aspect of the present invention is slidably supported by a heat welding jig which moves toward and away from the imperfectly formed portion of the seal groove. Therefore, while the heat welding jig engages with the regular shape portion of the seal groove before contacting the imperfectly shaped portion, the positioning jig and the heat welding jig are engaged when the heat welding jig enters the seal groove to a specified depth. The positioning jig is prevented from moving relative to the jig, and functions as a stopper for regulating the stroke of the heat welding jig.

Therefore, according to the first to sixth aspects of the present invention, both of the halved parts are joined together, and the incompletely formed part formed at the end of the seal groove of each halved part is melted. By connecting the seal grooves to each other, at least the occurrence of a large step at the joint between the seal grooves is eliminated, and even if the seal grooves are slightly shifted, the incompletely shaped portion is melted. Both seal grooves are smoothly connected to each other via the newly formed groove.

[0015] Further, as in the invention according to claim 7, by regulating the stroke of the heat welding jig for welding by the positioning jig, a step is also generated at the bottom of the seal groove. Connected without.

[0016]

According to the first aspect of the present invention, in forming a tubular body by joining two halved parts against each other at their divided surfaces to form a tubular body, the halved parts are formed simultaneously with the forming of the halved parts. The end of the seal groove on the split surface side is formed in advance into an incomplete shape, and after joining the half-split parts, the incompletely shaped part of the seal groove formed in both half-split parts is melted. They are connected to each other while finishing in a regular shape.

Therefore, the seal grooves are smoothly connected to each other without generating a large step, based on a method of allowing the generation of a joint line at the joint flange portion. When the seal member is mounted in the groove, the seal member does not properly fit in the seal groove and does not lower the sealing performance, so that there is an effect that both cost reduction and improvement of the sealing performance can be achieved.

Further, the above-mentioned incompletely shaped portion is defined in claim 2.
In the case where the end of the seal groove of the half-split part is not opened beforehand as in the invention described in the above, or in the case where the groove width of the end of the seal groove is narrowed in advance as in the invention of the third aspect In addition to the same effect of the invention according to claim 1, the incompletely shaped portion itself is melted, so that the original function of the seal groove is not hindered. There is an effect that molding can be performed very easily at the time of molding.

According to the fourth aspect of the present invention, the heat welding jig for melting and connecting the incompletely formed portions of the seal grooves has a groove width equivalent to the regular shape portion of the seal grooves. Therefore, in addition to the same effect as the invention according to any one of claims 1 to 3, there is an effect that the groove width at the connecting portion between the seal grooves can be accurately finished.

According to the fifth aspect of the present invention, the above-mentioned heat welding jig has a positioning jig which simultaneously engages with a regular shape portion of the seal grooves formed in both the half parts. Since the heat welding jig melts the incompletely shaped portion while being guided by the positioning jig, in addition to the same effect as the invention according to claim 4, the incompletely shaped portion and the heat The relative positioning with the welding jig can be performed more accurately, and there is an effect that both seal grooves can be connected more smoothly.

In particular, since the tip of the positioning jig is formed in a tapered shape as in the invention according to the sixth aspect, in addition to the same effect as the invention according to the fifth aspect, an incompletely formed portion is provided. The relative positioning between the heat welding jig and the heat welding jig can be more accurately performed.

According to the seventh aspect of the present invention, the stroke of the heat welding jig is regulated by the positioning jig. There is an effect that the depth of the connection portion between the seal grooves formed by the melting of the complete shape portion can be finished accurately and without any step.

[0023]

1 to 6 show a typical embodiment of the present invention. FIG. 2 shows a tubular body 1 formed by the forming method of the present invention.

As shown in FIG. 2, a tubular body 1 as a product has rectangular joining flange portions 3 and 4 having a diameter larger than that of the tubular portion 2 integrally formed at both ends of a tapered tubular portion 2. A portion of the joint flange portions 3 and 4 that is to be a joint surface with a counterpart member has a closed loop shape having a rectangular cross section so as to surround the open end of the tubular portion 2. Seal groove 5
Are formed.

As shown in FIG. 1A, the tubular body 1 is divided into two parts by a plane which crosses the closed loop-shaped seal groove 5, more specifically, a plane which passes through the axis thereof. , 6 are molded in advance by a resin injection molding method, and the two half parts 6, 6 are joined together by a joining method such as vibration welding after butting against each other on a dividing surface 7. Yes, but each half part 6,6
In forming the sealing flanges 5, 8 of the flange pieces 8, 8 that are to be the joining flange portions 3 when forming the unformed portion 9, an unopened portion 9 is formed in advance as an incompletely shaped portion at the end on the division surface 7 side.

That is, the end of the seal groove 5a of each of the flange pieces 8, 8 is to be opened toward the dividing surface 7 side. An unopened portion 9 such as a weir is formed in advance by stopping at a distance a shown in FIG.

Then, as shown in FIG. 1 (B), the two half parts 6, 6 are joined together by a method such as vibration welding by abutting each other on the divided surface 7 thereof. Subsequent to the joining operation, relative positioning between the seal grooves 5a, 5a of the two half parts 6, 6 and the heat welding jig is performed by using a positioning pin 15, which is a positioning jig, so that the seal grooves 5a, 5a are mutually connected. Connect.

The above is exactly the same for the other connecting flange 4 side.

More specifically, a heat-welding plate 11 as a heat-welding jig is provided on the support 10 shown in FIG.
2, a holder plate 13 is integrally fixed to the upper portion of the heat welding plate 11, and the holder plate 13 is sandwiched between the heat welding plates 11 on both sides thereof. A positioning pin 15 having a stopper nut 14 is vertically movably supported.

Since the above-mentioned heat welding plate 11 melts the unopened portion 9 as will be described later, its width is set in advance to the same size as the regular width b of the seal groove 5a. Each of the positioning pins 15 is constantly urged downward by the compression coil spring 16 in FIG. 1B, and the diameter thereof is set to be large enough to enter the seal groove 5a as shown in FIG. And the tip is formed in a tapered shape.

As shown in FIG. 1B, before the positioning pin 15 is engaged with the seal groove 5a, the tip of the positioning pin 15 is positioned below the lower surface of the heat welding plate 11. While (A),
As shown in (B), the heat welding plate 11 is set so as to contact the unopened portion 9 after the positioning pin 15 is seated on the bottom of the seal groove 5a, and as shown in FIG. The upper surface of the stopper nut 14 is set to contact the holder plate 13 when the lower surface of the heat welding plate 11 is flush with the bottom surface of the seal groove 5a. That is, the stopper nut 14 serves to regulate the stroke of the heat welding plate 11, and this stroke is
4 can be finely adjusted by rotating it.

Therefore, as shown in FIG. 1B, in melting the unreleased parts 9, 9 after the half parts 6, 6 are joined together, the flange pieces 8, 8, which have been joined first, are melted. When the heat welding plate 11 is lowered together with the support 10 from above, the heat welding plate 11 is brought into contact with the unopened portions 9 at the ends of the seal grooves 5a, 5a as shown in FIG. As shown, each positioning pin 15 is seated on the bottom thereof while engaging with the seal groove 5a.

At this time, the seal grooves 5a of the two flange pieces 8 have the same size as shown in FIGS. Even if offset by the dimension c, as long as the dimension c is substantially equal to or less than half of the regular groove width dimension b of the seal groove 5a, the self-aligning function of each positioning pin 15 causes the heat welding plate 11 Is corrected, and the relative positioning between the seal grooves 5a, 5a and the heat welding plate 11 is performed.

That is, as shown in FIGS. 3A and 3B, even if the two seal grooves 5a are offset from each other by the dimension c, both the seal grooves 5a are allowed while allowing the offset amount c. The attitude of the heat welding plate 11 is gradually and obliquely corrected so as to connect the grooves 5a, 5a smoothly.

Then, as shown in FIG. 5B, when the heat welding plate 11 is still lowered even after the positioning pins 15 are seated on the bottom surfaces of the seal grooves 5a, 5a, the pre-heated heat welding is performed. The plate 11 is pressed against the unopened portions 9, 9 and a portion corresponding to the unopened portions 9, 9 is melted so as to communicate the two seal grooves 5a, 5a. Finish to 5a, 5a regular groove width dimension b.

As a result, for the first time at this stage, the unopened portions 9,
9, the two seal grooves 5a, 5a are continuous with the same groove width b, while the above-mentioned unopened portions 9, 9 are melted, and the vicinity of the division surface 7 between the flange pieces 8, 8 is formed. Are thermally welded. That is, (A) of FIG.
As shown in (B), while the offset amount c between the two seal grooves 5a, 5a is allowed, the unreleased portions 9, 9 are melted and eliminated, resulting in the unreleased portions 9, 9. The two seal grooves 5a, 5a,
5a are connected relatively smoothly without a large step. In other words, even if the connecting portion between the seal grooves 5a, 5a is oblique, as long as the same groove width as that of the regular dimension b is secured, the seal member is correctly mounted in the seal groove 5. The sealing performance is not reduced.

At this time, as described above, the heat welding plate 11 has the same width dimension as the groove width dimension b of the seal grooves 5a, 5a, and is flush with the bottom surfaces of the seal grooves 5a, 5a. Stop at the position where both seal grooves 5a, 5
Even at the bottoms of a, they are smoothly continued without any step.

Then, as described above, each seal groove 5
When the a and 5a communicate with each other to form a closed loop-shaped seal groove 5, the heat welding plate 11 is returned to the state shown in FIG. 1 (B), and the operation is completed, whereby the tubular body shown in FIG. 1 is molded. In addition, the positioning pin 15 is used for each of the seal grooves 5a,
It is desirable that the positioning pin 15 and the heat welding plate 11 be urged by an elastic body such as a spring so that the positioning pin 15 and the heat welding plate 11 autonomously return to the original neutral position when they exit from the position a.

Here, in the above-described embodiment, the case where the unopened portion 9 is formed as shown in FIG. 3 as an incompletely shaped portion is exemplified. However, instead of this, for example, as shown in FIG. grooves 5a, 5a of the groove width b of the end portion is locally reduced formation of a b ₁ dimensions, may the fine groove 17 as an incomplete shape portion, in this case, by heat welding plate 11, fine The groove portion 17 is a regular groove width dimension b of the seal groove 5a.
Spread out to be the same as.

As described above, according to each of the embodiments, while the occurrence of the joint line on the division surface 7 between the half-parts 6 and 6 is allowed, the portion where the seal grooves 5a and 5a are connected is large. Since it is possible to smoothly continue without generating a step, it is possible to prevent a decrease in sealing performance when a predetermined sealing member is mounted in the sealing groove 5 as in the prior art. This is effective when molding an intake manifold.

[Brief description of the drawings]

FIG. 1 is a diagram showing a typical embodiment of the present invention;
(A) is an exploded perspective view of a tubular body, and (B) is a cross-sectional view of a main part at the time of joining half-split parts.

FIG. 2 is a perspective view of a tubular body.

3 (A) is an enlarged perspective view of a main part of FIG. 1 (B),
FIG. 2B is a perspective view showing a state after the unreleased portion in FIG.

FIG. 4 is an enlarged sectional view of a main part showing a relationship between a positioning pin and a seal groove.

FIG. 5 is an operation explanatory view of FIG. 1 (B).

FIG. 6 is a perspective view of a main part showing a second embodiment of the present invention.

FIG. 7 is a cross-sectional view of a tubular body formed by a conventional forming method.

FIG. 8 is a left side view of FIG. 7;

FIG. 9 is a right side view of FIG. 7;

FIG. 10 is an exploded perspective view of the tubular body shown in FIG. 7;

FIG. 11 is an explanatory diagram showing a state in which a step is generated at the time of joining.

FIG. 12 is an exploded view of a tubular body formed by another conventional forming method.

FIG. 13 is an explanatory sectional view of a mold for molding the tubular body shown in FIG. 12;

FIG. 14 is an operation explanatory view of FIG. 13;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tubular body 3, 4 ... Joining flange part 5, 5a ... Seal groove 6 ... Half-split part 7 ... Dividing surface 8 ... Flange piece 9 ... Unopened part (incomplete shape part) 11 ... Heat welding plate (Heat welding) Jig) 15 ... Positioning pin (Positioning jig) 17 ... Narrow groove (Incomplete shape part) 18 ... Groove

Claims (7)

[Claims] 1. A resin-made tubular body having a large-diameter joint flange at an end thereof and a closed-loop-shaped seal groove formed at a portion of the joint flange to be a joint surface with a counterpart. A method of forming a half part having a shape obtained by dividing a tubular body including a joining flange portion into two parts at a plane crossing a seal groove of the joining flange part, and dividing the two half parts with each other at the dividing surface. Abutting and joining steps, wherein, of the seal grooves simultaneously formed at the time of forming the half-split parts, the ends on the split surface side are preliminarily formed into an incomplete shape, A method of forming a resin tubular body having a joining flange portion, wherein after joining, an incompletely shaped portion of a seal groove formed in both halves is melted and finished to a regular shape to connect them. 2. The incompletely formed portion preformed at the end of the seal groove is formed by the end of the seal groove being interrupted near the division surface without being opened to the division surface side. The method for forming a resin tubular body having a joint flange portion according to claim 1. 3. An incompletely formed portion formed in advance at an end of the seal groove has a groove width narrower than a regular dimension in the vicinity of the division surface although the end of the seal groove is open to the division surface side. The method for molding a resin tubular body having a joining flange portion according to claim 1, wherein the resin tubular body is formed by being formed. 4. A heat welding jig having a width dimension equal to the groove width of the regular shape portion of the seal groove, wherein the imperfect shape portion of the seal groove is melted and finished to have a regular shape. The method for molding a resin tubular body having a joint flange portion according to claim 1. 5. The heat welding jig has a positioning jig which simultaneously engages with a regular shape portion of a seal groove formed in both half parts, and is guided by the positioning jig. The method according to claim 4, wherein the heat welding jig melts the incompletely formed portion. 6. The method according to claim 5, wherein a tip of the positioning jig is formed in a tapered shape. 7. The positioning jig is slidably supported by a heat welding jig that moves toward and away from the incompletely shaped portion of the seal groove, and the heat welding jig contacts the incompletely shaped portion. While previously engaging with the regular shape portion of the seal groove, when the heat welding jig enters the seal groove to the specified depth, the relative movement between the positioning jig and the heat welding jig is prevented, and the positioning jig is 7. A function as a stopper for regulating a stroke of the heat welding jig.
A method for molding a resin tubular body having the joint flange portion according to the above.