JPH1134811A - Manufacture of resin-made tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a resin-made tank, which is capable of forming the sealing surface of a perforation high surface roughness at smaller cost without any complicated process. SOLUTION: A molding die 30 is provided with a blade tool 38 lodged therein more inside than the die face. The parison expanded in the die 30 adheres to the peripheral wall of the tool 38 and forms a hollow body T having the inner peripheral wall of a perforation 12 defined by the peripheral wall of the tool 38. The tool 38 is thereafter advanced to cut the part of the parison on the tool 38 to remove the cut piece S, which process manufactures a washer tank. The inner peripheral wall of the perforation 12 is formed not as a cut face but conforming to the peripheral wall of the tool 38 to have larger surface roughness. This method requires only a single blow-molding process for the less number of manufacturing processes leading to cost reduction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a resin tank having a through hole in a side wall, and more particularly to a method of manufacturing a resin tank to which hollow molding (blow molding) is applied.

[0002]

2. Description of the Related Art As a resin tank manufactured by blow molding (blow molding), for example, a washer tank applied to a wiper device of a vehicle and containing a liquid such as a window washer liquid is known.

In this type of washer tank, as shown in FIG. 18, a water supply through hole 82 is formed in a side wall portion of the tank 80. Generally, in the vicinity of the through hole 82,
The water supply pump 84 is attached to the tank 80 itself. The pump 84 has an inlet 86 whose grommet 8
8, it is fitted into the through hole 82, thereby ensuring the sealing performance around the through hole 82. When the pump 84 operates, the washer fluid in the tank 80 is absorbed by the pump 84 and discharged from the outlet 90.

By the way, as described above, the through hole 8 of the tank 80 is used.
In FIG. 2, a grommet 88 is interposed between the inlet 86 of the pump 84 and the grommet 88, so that the sealing performance of the through hole 82 is ensured. Is the inner peripheral wall of the through hole 82 (that is,
A high surface roughness is required for the contact surface with the grommet 88). In other words, if the surface roughness of the inner peripheral wall of the through hole 82 is poor,
Adhesion with the grommet 88 deteriorates, resulting in poor sealing.

For this reason, conventionally, after forming the main body portion (hollow body) of the tank 80 by hollow molding, it is processed by a tool such as a drill to form the through-hole 82 and to seal the sealing surface (in the through-hole). The surface roughness of the peripheral wall is secured. Therefore, the number of manufacturing steps is large and it takes time and effort to manufacture, which is a cause of high cost.

In this case, a manufacturing technique has been proposed which does not require post-processing using a tool such as a drill and can form the through-holes 82 when the tank 80 is formed by hollow molding (Japanese Patent Publication No. Hei 3 (1994)). -76808).

According to the manufacturing technique disclosed in the above-mentioned publication, a tool with a blade constituting a cavity is provided so as to enter outside the mold surface (cavity) of a molding die, and the parison is expanded to expand the hollow body. Is formed, the side wall portion of the hollow body is cut off (drilled) by the tool with a blade to form the through hole 82. According to this manufacturing technique, post-processing using a tool such as a drill is not required after the tank 80 (hollow body) is formed by hollow molding,
The tank 80 can be formed in one manufacturing process.

However, in the manufacturing technique disclosed in the above-mentioned publication, since the through-hole 82 is formed by cutting (piercing) the side wall portion of the hollow body with a bladed tool, the inner peripheral wall of the through-hole 82 is formed. The portion (seal surface) is a cut surface. Therefore, there is a disadvantage that the roughness of the inner peripheral wall portion (seal surface) is poor (necessary surface roughness cannot be secured), and as a result, poor sealing tends to occur. Therefore, the tank 80 manufactured by the manufacturing technique disclosed in the above publication cannot be applied to a washer tank of a vehicle or the like.

[0009]

SUMMARY OF THE INVENTION In consideration of the above-mentioned facts, the present invention can form a sealing surface of a through hole with a high surface roughness and at a low cost without requiring complicated processing. It is an object to obtain a method of manufacturing a resin tank that can be realized.

[0010]

According to a first aspect of the present invention, there is provided a method for manufacturing a resin tank having a through hole in a side wall portion. A tool with a blade having the following is protruded in a state in which it enters the inside of the mold from the mold surface, and is provided in advance in the mold, and the resin parison is expanded in the mold and the resin parison is pressed against the mold. At the same time, the resin parison is brought into close contact with the peripheral wall of the tool with a blade, and the cutting edge of the tool with the blade enters into the inside of the resin parison more than the pressed wall thickness of the general part of the resin parison. A hollow body is formed in a state where the inner peripheral wall of the hollow body is formed, and then the bladed tool is advanced toward the inside of the hollow body to remove the resin parison of the hollow body corresponding to the cutting edge of the bladed tool. Cut off the through hole Formed, further, the bladed tool with disengaging from said hollow body, open the mold is taken out a hollow body in which the through hole is formed, is characterized in that.

In the method for manufacturing a resin tank according to the first aspect, the bladed tool is provided in the mold in advance so as to protrude from the mold surface into the interior of the mold. By expanding the resin parison in the mold, the parison is pressed against the mold and is brought into close contact with the peripheral wall of the bladed tool.

In this state, the cutting edge of the tool with a blade enters the inside of the resin parison more than the pressed general thickness of the parison, and the inner peripheral wall surface of the through hole is formed by the peripheral wall of the tool with the blade. A hollow body is formed.

Next, when the bladed tool is advanced toward the inside of the hollow body, the resin parison of the hollow body corresponding to the cutting edge of the bladed tool is cut off to form a through hole. Further, the resin-made tank is manufactured by removing the bladed tool from the hollow body, opening the mold, and taking out the hollow body having the through-hole formed therein.

According to the first aspect of the present invention, the resin parison is expanded in the molding die and the resin parison adheres to the peripheral wall of the bladed tool to form a through hole. Is done. That is, since the inner peripheral wall surface of the through hole is formed not according to the cut surface but following the peripheral wall of the bladed tool (since the peripheral wall of the bladed tool becomes the inner peripheral wall surface of the through hole as it is), The roughness of the peripheral wall portion (seal surface) can be increased (the required surface roughness can be secured). Therefore, the sealing property of the through hole can be ensured, and it can be suitably used for, for example, a washer tank of a vehicle.

In addition, the through-hole can be formed at the same time when the hollow body is formed by hollow molding, instead of the conventional configuration in which the through-hole is formed by post-processing using a tool such as a drill. The provided resin tank can be formed in a single manufacturing process, and the cost can be reduced.

As described above, in the method for manufacturing a resin tank according to the first aspect, the sealing surface of the through-hole can be formed with a high surface roughness, and the sealing surface can be formed without requiring complicated processing. It can be realized by cost.

According to a second aspect of the present invention, in the method for manufacturing a resin tank according to the first aspect, the resin parison in the hollow body corresponding to the cutting edge is cut by the bladed tool. At this time, the cutting piece is held by the tool with a blade, and when the tool with the blade is detached from the hollow body, the cutting piece is removed from the hollow body together with the tool with the blade. .

In the method for manufacturing a resin tank according to the second aspect, when the resin parison of the hollow body corresponding to the cutting edge is cut by the tool with a blade, the cut piece is held by the tool with the blade, and further, the cutting piece is held. When the tool is detached from the hollow body, the cutting piece together with the bladed tool is removed from the hollow body.

Therefore, the cut piece of the resin parison does not fall into the hollow body and remains, so that a step of removing the cut piece remaining after opening the mold and taking out the hollow body becomes unnecessary. In addition, the number of steps can be reduced and the cost can be reduced.

According to a third aspect of the present invention, there is provided a resin tank manufacturing method according to the first or second aspect, wherein the bladed tool is a pair of male and female split molds. It is characterized in that the through-hole is formed by providing the through-hole at a position near the joining portion.

In the method for manufacturing a resin tank according to the third aspect, the bladed tool is provided at a position near the matching portion of a pair of male and female split molds, and the through hole is formed.

Here, a resin parison (a part other than a part formed as a product in a resin tank) is photographed and held in the mold matching part of the split mold. Therefore, when the bladed tool is advanced toward the inside of the hollow body to cut the resin parison of the hollow body to form a through hole, the hollow body (a general part of the resin parison) is moved with the movement of the bladed tool. The resin parison corresponding to the through-hole can be reliably cut off without unnecessary displacement or movement. Therefore, the product accuracy is further improved.

According to a fourth aspect of the present invention, there is provided a resin tank manufacturing method according to the first, second or third aspect, wherein the undercut portion is formed in the hollow body. Constituting the cavity of the mold,
Further, the through-hole is formed by providing the tool with a blade at a position near the forming die corresponding to the undercut portion.

In the method of manufacturing a resin tank according to the present invention, the cavity of the mold is formed so as to form an undercut portion in the hollow body, and the vicinity of the mold corresponding to the undercut portion of the hollow body is provided. A tool with a blade is provided at the position to form a through hole.

Here, the undercut portion of the hollow body is, of course, difficult to separate from the mold, in other words, the hollow body is securely held by the mold. Therefore, when the bladed tool is advanced toward the inside of the hollow body to cut the resin parison of the hollow body to form a through hole, the hollow body (a general part of the resin parison) is moved with the movement of the bladed tool. The resin parison corresponding to the through-hole can be reliably cut off without unnecessary displacement or movement. Therefore, the product accuracy is further improved.

[0026]

FIG. 5 shows the structure of a main part of a washer tank 10 as a resin tank manufactured by applying the method for manufacturing a resin tank according to the first embodiment of the present invention. This is shown in a front view. FIG. 6 is a bottom view showing a configuration of a main part of the washer tank 10.

The washer tank 10 is applied to, for example, a wiper device of a vehicle, and can store a liquid such as a window washer liquid.

In the side wall portion of the washer tank 10, a water supply through hole 12 is formed. Further, a pair of pump fitting portions 14 facing each other are formed in a side wall portion near the through hole 12. As will be described later in detail, the pump fitting portion 14 is an undercut portion when the washer tank 10 is manufactured by blow molding. A water supply pump 16 is fitted and attached to the pump fitting portion 14. The pump 16 has an inlet 18 fitted into the through-hole 12 through the grommet 20, thereby ensuring the sealing around the through-hole 12. When the pump 16 operates, the washer tank 10
In this configuration, the washer fluid inside is absorbed by the pump 16 and discharged from the outlet 22.

Here, FIG. 1 is a sectional view showing main steps of a method for manufacturing a resin tank according to the first embodiment of the present invention.

The present manufacturing method is basically a hollow molding (blow molding), and can manufacture the above-mentioned washer tank 10, and uses a pair of male and female split molds 30 and 32. A cavity 34 corresponding to the washer tank 10 (product) is formed by the pair of split molds 30 and 32.

A tool hole 36 is formed in one molding die 30, and a tool 38 with a blade is arranged in the tool hole 36. The tool 38 with a blade is formed in a columnar shape, and further has a blade edge portion 40 at the tip as shown in detail in FIGS. 2 and 3.

In this case, the tool hole 36 (that is, the tool 38 with the blade) is formed in the through hole 12 of the washer tank 10 described above.
And the mold 3 near the tool hole 36.
At 0, a cavity 34 is formed to form the pump fitting portion 14 (undercut portion).

Further, a cylinder 44 is fixed to the molding die 30 via a fixing table 42. Cylinder 44
The rod 46 is connected to the rear side of the bladed tool 38 so that the rod 46 expands and contracts by the operation of the cylinder 44 so that the bladed tool 38 can be moved in the tool hole 36.

Here, when the washer tank is formed, the bladed tool 38 is used to form the surface of the forming die 30 (the cavity 3).
It is provided in advance so as to protrude further into the inside than in 4).

Next, FIG. 4 is a flowchart showing the specific steps of the method of manufacturing the resin tank according to the first embodiment, and the specific steps of the present method are described in accordance with the flowchart. explain.

As described above, when the washer tank 10 is formed, the bladed tool 38 is provided in advance so as to protrude from the mold surface of the mold 30 into the interior.

After setting the split molds 30 and 32 and the bladed tool 38 in this way, first, in step 100, a resin parison is injected. Further, in step 102, the injected resin parison is sagged and stretched by its own weight. The temperature of the resin parison in this step is, for example, 185 degrees.

Next, in step 104, the resin parison is clamped by the split molds 30 and 32.
In step 106, compressed air is blown (air blown) into the resin parison while the clamping pressure by the split molds 30 and 32 is maintained. The air blow time is, for example, 35 seconds.

As a result, the resin parison expands in the cavities 34 of the split molds 30 and 32, and the resin parison presses the mold surfaces (cavities 34) of the split molds 30 and 32 as shown in FIGS. And the bladed tool 38
Closely attached to the surrounding wall.

In this state, the cutting edge portion 40 of the bladed tool 38 penetrates more than the general thickness of the pressed resin parison, and the inner peripheral wall surface of the through hole 12 is formed by the peripheral wall of the bladed tool 38. Then, a hollow body T is formed.

Next, in step 108, the cylinder 44 is operated to advance the bladed tool 38 toward the inside of the hollow body T (the split molds 30, 32). Thereby, as shown in FIG. 3, the resin parison of the hollow body T corresponding to the cutting edge portion 40 of the bladed tool 38 is cut off, and the through hole 12 is formed. At this point, the hollow body T (resin parison)
Is, for example, 120 degrees.

After the resin parison of the hollow body T is cut off to form the through-holes 12, in step 110, the bladed tool 38 is held in its moving state (for example, 1).
0 seconds). In this state, the hollow body T and the cut piece S are cooled to about 90 degrees.

Further, in step 112, the cylinder 44 is operated again, and the bladed tool 38 is moved backward in the opposite direction to the above-mentioned direction so as to be separated from the hollow body T (the split molds 30, 32). At this time, the cut piece S may fall into the hollow body T, but the cut piece S does not adhere to the inside of the hollow body T because it has already been cooled in step 110.

Thereafter, in Step 114, the air in the split molds 30 and 32 is evacuated and exhausted.
At 6, the split molds 30 and 32 are opened. Further, in step 118, the washer tank 10 made of resin is manufactured by taking out the hollow body T in which the through-hole 12 is formed. At this point, the washer tank 10
Is 88 degrees, for example. When the cut pieces S fall into the hollow body T, a step of taking out the cut pieces S remaining inside the hollow body T is performed after the step 118.

According to the method for manufacturing a resin tank according to the first embodiment, the resin parison expands in the split molds 30 and 32 so that the resin parison is attached to the peripheral wall of the bladed tool 38. By the close contact, the through-hole 12 of the washer tank 10 is formed. That is, since the inner peripheral wall surface of the through hole 12 is formed not according to the cut surface but according to the peripheral wall of the bladed tool 38 (the peripheral wall of the bladed tool 38 is directly covered with the through hole 1).
2), it is possible to increase the roughness of the inner peripheral wall portion (seal surface) (a required surface roughness can be secured). Therefore, the sealing property of the through hole 12 can be ensured, and it is most suitable as a vehicle washer tank.

Further, instead of the conventional structure in which the through-hole 12 is formed by post-processing using a tool such as a drill, the through-hole 12 is simultaneously formed when the hollow body T is formed by blow molding.
Can be formed, and the washer tank 10 having the through-hole 12 can be formed in a single manufacturing process, so that the cost can be reduced.

Further, in the method of manufacturing a resin tank according to the first embodiment, as shown in FIG. 7, the mold surface (cavity 34) of the molding die 30 is
4 (undercut)
Mold 30 corresponding to pump fitting portion 14 of hollow body T
Is provided with a bladed tool 38 (tool hole 36) in the vicinity of, and the through hole 12 is formed.

Here, as shown in FIG. 8, the pump fitting portion 14 (undercut portion) of the hollow body T is of course
The hollow body T is hard to be separated from 0, in other words, the hollow body T is securely held by the mold 30. Therefore, the aforementioned step 1
At 08, when the bladed tool 38 is advanced toward the inside of the hollow body T to cut the resin parison of the hollow body T to form the through hole 12, the hollow body T (the resin The resin parison corresponding to the through hole 12 can be reliably cut off without unnecessarily shifting or moving the parison (a general part of the parison). For this reason, the product accuracy of the washer tank 10 is further improved.

As described above, in the method for manufacturing the resin tank according to the first embodiment, the sealing surface of the through hole 12 of the washer tank 10 can be formed with a high surface roughness.
In addition, this can be realized at low cost without requiring complicated processing.

Next, another embodiment of the present invention will be described. Note that components and manufacturing steps that are basically the same as those in the first embodiment are given the same reference numerals as in the first embodiment, and descriptions thereof are omitted.

FIGS. 9 and 10 are sectional views showing main steps of a method for manufacturing a resin tank according to the second embodiment of the present invention.

In the method for manufacturing a resin tank according to the second embodiment, a bladed tool 48 is used in place of the bladed tool 38 of the first embodiment. The bladed tool 48 has a blade tip 50 formed at the tip and a holding pin 52 protruding therefrom. The holding pin 52 has a function of holding the cut piece S as it is when the cutting tool 48 is advanced to cut the resin parison of the hollow body T corresponding to the cutting edge portion 50.

Also in the second embodiment, when the washer tank 10 is formed, the bladed tool 48 is provided in advance so as to protrude into the inside of the mold 30 from the mold surface. I have.

In the method for manufacturing a resin tank according to the second embodiment, the washer tank 10 is formed by basically the same steps as those shown in FIG.
In FIG. 6, when the resin parison is pressed against the mold surfaces of the split molds 30 and 32 and adheres closely to the peripheral wall of the bladed tool 48, the resin parison also adheres to the periphery of the holding pin 52 (FIG. 9). State shown). Further, in step 108,
By operating the cylinder 44, the bladed tool 48 is
When it is advanced toward the inside of the (split molds 30, 32),
As shown in FIG. 10, the resin parison of the hollow body T corresponding to the cutting edge portion 50 of the bladed tool 48 is cut off to form the through hole 12.

Further, in step 110, the bladed tool 4
When the moving piece 8 is held in the moving state, the cut piece S is positively held by the holding pin 52. Therefore, after that, the bladed tool 48 is connected to the hollow body T (divided molds 30, 3).
Even when detached from 2), the cut piece S is removed from the hollow body T together with the bladed tool 48.

Therefore, the cut piece S of the resin parison does not fall into the hollow body T and remains. Therefore, the cut piece S remaining after the split molds 30 and 32 are opened and the hollow body T is taken out. The step of taking out S again becomes unnecessary, so that the number of steps can be reduced and the cost can be reduced.

Note that in the second embodiment,
Although the holding pin 52 is configured to protrude from the tip of the bladed tool 48, the shape of the holding pin 52 is not limited to this, and may be any configuration that can hold the cut piece S.

For example, a holding groove 60 may be formed at the tip as in a bladed tool 58 shown in FIG.
According to the bladed tool 58, when the resin parison is pressed against the mold surfaces of the split molds 30 and 32 and is brought into close contact with the peripheral wall of the bladed tool 58, the resin parison is also in the holding groove 60. Penetrate. Therefore, the bladed tool 58 is connected to the hollow body T
After the resin parison of the hollow body T is cut off by advancing in the inner direction of the (split molds 30, 32), the cut pieces S are held by the holding grooves 60. Therefore, even if the bladed tool 58 is subsequently separated from the hollow body T (the split molds 30 and 32), the cut pieces S are removed from the hollow body T together with the bladed tool 58 and fall into the hollow body T. As a result, there is no need to remove the resection piece S again, and the number of steps can be reduced and the cost can be reduced.

Further, for example, a wedge-shaped holding projection 66 may be formed at the tip as in a bladed tool 64 shown in FIG. According to the bladed tool 64, the holding projection 66
Is formed in a thick inverted wedge shape, so that the holding force of the cut piece S is significantly improved. Therefore, the cut piece S can be more reliably removed from the hollow body T together with the bladed tool 64, which is more effective. Further, a wedge-shaped holding concave portion 72 may be formed at the tip as in a bladed tool 70 shown in FIG. Even in this case, similarly, the holding force of the resection piece S is significantly improved, which is more effective.

Next, FIGS. 14 and 15 are sectional views showing main steps of a method for manufacturing a resin tank according to the third embodiment of the present invention.

In the method of manufacturing a resin tank according to the third embodiment, a bladed tool 100 is used in place of the bladed tool 38 of the first embodiment. The tool 100 with a blade has a blade edge portion 102 formed at the tip. The cutting edge portion 102 is formed to be conical inclining from above to below (only the upper portion has a pointed shape).
When cutting the resin parison of the hollow body T corresponding to the cutting edge portion 102 by moving the bladed tool 100 forward, only the upper part of the resin parison is cut, and the uncut parison piece P remains at the lower part. ing.

Incidentally, also in the third embodiment, when the washer tank 10 is formed,
Is provided in advance so as to protrude into the inside of the mold 30 from the mold surface.

In the method for manufacturing a resin tank according to the third embodiment, the washer tank 10 is formed by basically the same steps as those shown in FIG.
In FIG. 8, the cylinder 44 is operated to
When 0 is advanced toward the inside of the hollow body T (split molds 30, 32), only the upper part of the resin parison of the hollow body T corresponding to the cutting edge 102 of the bladed tool 100 is cut as shown in FIG. The lower portion of the resin parison is bent toward the bottom of the hollow body T as the bladed tool 100 advances without being cut. In this state, in step 110, the bladed tool 100 is held in its moving state, and the hollow body T and the parison piece P are cooled and solidified to form the through holes 12.

As described above, also in the method for manufacturing the resin tank according to the third embodiment, a sealing surface necessary for bringing the grommet 20 into close contact can be secured.
For example, as shown in FIG.
If the surface roughness of the portion is high, a sealing surface can be secured.

In the method for manufacturing a resin tank according to the third embodiment, the parison piece P after the through-hole 12 is formed is held as it is and falls into the hollow body T and remains. Therefore, there is no need for a step of taking out the parison pieces P remaining after the split molds 30 and 32 are opened and the hollow body T is taken out, so that the number of steps can be reduced and the cost can be reduced.

Further, in the method for manufacturing a resin tank according to the third embodiment, the washer tank 10
When actually used, by the parison piece P,
It is also possible to prevent foreign matter such as dust remaining at the bottom of the washer tank 10 from entering the through hole 12 (in other words, the parison piece P serves as a wall for preventing foreign matter from entering). . Therefore, for example, it is possible to prevent the pump 16 from being damaged due to foreign matter intrusion, and the like, which is more effective.

Incidentally, in the third embodiment,
By forming the blade edge portion 102 of the bladed tool 100 in a conical manner from the upper side to the lower side in a conical shape (only the upper part has a sharp shape), the parison piece P that cuts only the upper part of the resin parison and is not cut at the lower part Although it is configured to remain, the shape (configuration) of the bladed tool 100 for cutting so that the parison piece P that is not cut when forming the through hole 12 remains is not limited to this.

For example, as shown in FIGS. 16 and 17, a bladed tool 10 comprising an upper blade portion 104A and a lower body portion 104B.
It may be four. In the bladed tool 104, the upper blade 1
Only 04A is configured to advance toward the inside of the hollow body T (split molds 30, 32).

According to the bladed tool 104, the upper blade 10
By advancing only 4A, only the upper part of the resin parison of the hollow body T corresponding to the bladed tool 104 is cut,
The lower part of the resin parison is not cut and the upper blade 104
With the advance of A, the hollow body T is directly bent toward the bottom. Thereby, the through hole 12 and the parison piece P are formed in the same manner as described above.

Even in this case, it is possible to secure a sealing surface necessary for bringing the grommet 20 into close contact. Further, since the parison piece P after the formation of the through hole 12 is held as it is and does not fall into the hollow body T and remains, the split molds 30 and 32 are opened and the hollow body T is taken out. The step of taking out the remaining parison piece P again becomes unnecessary, so that the number of steps can be reduced and the cost can be reduced.

Further, the manufactured washer tank 10
When actually used, by the parison piece P,
It is also possible to prevent foreign matter such as dust remaining at the bottom of the washer tank 10 from entering the through hole 12 (in other words, the parison piece P serves as a wall for preventing foreign matter from entering). . Therefore, for example, it is possible to prevent the pump 16 from being damaged due to foreign matter intrusion, and the like, which is more effective.

The cross-sectional shape and size of the blade tip 40 of the bladed tool 38 in each of the above-described embodiments can be arbitrarily changed, and if these are changed as desired, The through hole 12 can be formed not only in a circular shape but also in an arbitrary shape and size such as a square shape and an elliptical shape.

In each of the above embodiments,
Tool hole 36 (blade tool 38, blade tool 48, blade tool 5
8, the tool 64 with a blade, the tool 70 with a blade, the tool 100 with a blade, or the tool 104 with a blade) are provided in the vicinity of the molding die 30 corresponding to the pump fitting portion 14 of the washer tank 10 (hollow body T). Configuration (in other words, the pump fitting portion 14
Although the through hole 12 is formed at a position near the (undercut portion), the forming position of the through hole 12 (that is, the forming position of the tool hole 36) is not limited to this. For example, the tool hole 36 (the bladed tool 38, the bladed tool 48, the bladed tool 58, the bladed tool 64, the bladed tool 70, the bladed tool 10
0, or a tool 104 with a blade,
0, 32 cavities 34 (mold surface for molding hollow body T)
A configuration in which the through-hole 12 is formed by providing it at a position A (see FIG. 1) near the matching part (parting line) 33 other than the above.

In this case, a resin parison (product as a product) is formed in the washer tank 10 at a mold matching portion (parting line) 33 other than the cavity 34 (mold surface for molding the hollow body T) of the split molds 30 and 32. Other parts are taken and held. Therefore, when the bladed tool 38 or the like is advanced toward the inside of the hollow body T to cut the resin parison of the hollow body T and form the through hole 12, the hollow body T is moved with the movement of the bladed tool 38 or the like. (General part of resin parison) does not move or shift unnecessarily,
The resin parison corresponding to No. 2 can be reliably removed. For this reason, the product accuracy of the washer tank 10 is further improved.

Further, in each of the embodiments described above, the configuration is such that the bladed tool 38 and the like are moved by the cylinder 44, but the configuration for moving the bladed tool 38 and the like is not limited to this. For example, the bladed tool 38 and the like may be moved using a cam mechanism, a motor, an electromagnet, or the like.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing main steps of a method for manufacturing a resin tank according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing main steps of a method of manufacturing the resin tank according to the first embodiment of the present invention, in a state where a resin cavity is pressed against and closely attached to a mold surface.

FIG. 3 is a cross-sectional view showing main steps of a method for manufacturing the resin tank according to the first embodiment of the present invention, in which a resin parison corresponding to a through hole of a hollow body has been cut away.

FIG. 4 is a flowchart illustrating specific steps of a method for manufacturing a resin tank according to the first embodiment of the present invention.

FIG. 5 is a front view showing a configuration of a main part of a washer tank manufactured by applying the method for manufacturing a resin tank according to the first embodiment of the present invention.

FIG. 6 is a bottom view showing a configuration of a main part of a washer tank manufactured by applying the method for manufacturing a resin tank according to the first embodiment of the present invention.

FIG. 7 shows a mold surface (cavity) of a molding die corresponding to a pump fitting portion (undercut portion) of a washer tank manufactured by applying the method for manufacturing a resin tank according to the first embodiment of the present invention. FIG.

FIG. 8 is a schematic diagram showing a correspondence relationship between a pump fitting portion (undercut portion) and a molding die of a washer tank manufactured by applying the method for manufacturing a resin tank according to the first embodiment of the present invention. FIG.

FIG. 9 is a cross-sectional view illustrating main steps of a method for manufacturing a resin tank according to a second embodiment of the present invention, in a state where a resin cavity is pressed against and closely attached to a mold surface.

FIG. 10 is a cross-sectional view showing main steps of a method for manufacturing a resin tank according to a second embodiment of the present invention, in a state where a resin parison corresponding to a through hole of a hollow body is cut off.

FIG. 9 is a view showing a modified example of the bladed tool applied to the method for manufacturing a resin tank according to the second embodiment of the present invention;
It is sectional drawing corresponding to FIG.

FIG. 12 is a cross-sectional view showing a modified example of the bladed tool applied to the method of manufacturing a resin tank according to the second embodiment of the present invention.

FIG. 13 is a cross-sectional view showing a modified example of the bladed tool applied to the method for manufacturing a resin tank according to the second embodiment of the present invention.

FIG. 14 is a cross-sectional view showing main steps of a method for manufacturing a resin tank according to a third embodiment of the present invention, in a state where a resin cavity is pressed against and closely attached to a mold surface.

FIG. 15 is a cross-sectional view showing main steps of a method for manufacturing a resin tank according to a third embodiment of the present invention, in which a resin parison corresponding to a through-hole of a hollow body has been cut away.

FIG. 16 is a cross-sectional view showing main steps of a method for manufacturing a resin tank according to a modification of the third embodiment of the present invention, in a state where a resin cavity is pressed against and closely attached to a mold surface.

FIG. 17 is a cross-sectional view showing a main step of a method for manufacturing a resin tank according to a modified example of the third embodiment of the present invention, in which a resin parison corresponding to a through-hole of a hollow body has been cut away. is there.

FIG. 18 is a partially broken front view of a washer tank manufactured by general hollow molding (blow molding).

[Explanation of symbols]

 Reference Signs List 10 washer tank 12 through hole 14 pump fitting part (undercut part) 16 pump 30 molding die 32 molding die 34 cavity 36 tool hole 38 bladed tool 40 blade edge 48 bladed tool 50 bladed edge 52 holding pin 58 bladed tool Reference Signs List 60 holding groove 64 tool with blade 66 holding protrusion 70 tool with blade 72 holding recess 100 tool with blade 104 tool with blade T hollow body S cut piece P parison piece

Claims (4)

[Claims] 1. A method for producing a resin tank having a through hole in a side wall portion, wherein a tool with a blade having a columnar shape and having a cutting edge at a tip is inserted into the mold from the mold surface. The resin parison is expanded in advance in the molding die, and the resin parison is pressed against the molding die and the resin parison is brought into close contact with the peripheral wall of the bladed tool, and is pressed. The hollow body is formed in a state in which the cutting edge of the bladed tool enters the inside more than the general wall thickness of the resin parison and the inner peripheral wall surface of the through hole is formed by the peripheral wall of the bladed tool, The bladed tool is advanced toward the inside of the hollow body, and the resin parison of the hollow body corresponding to the cutting edge of the bladed tool is cut to form the through hole. When detached from the hollow body In the mold to open take out the hollow body the through hole is formed, a manufacturing method of a resin tank, characterized in that. 2. When the resin parison of the hollow body corresponding to the cutting edge is cut by the tool with the blade, the cut piece is held by the tool with the blade, and the tool with the blade is detached from the hollow body. The method for manufacturing a resin tank according to claim 1, wherein the cut piece is removed from the hollow body together with the bladed tool. 3. The resin according to claim 1, wherein the bladed tool is provided at a position near a matching portion of a pair of male and female split molds to form the through hole. Manufacturing method of a plastic tank. 4. A through-hole formed by forming a cavity of the molding die to form an undercut portion in the hollow body, and providing the bladed tool at a position near the molding die corresponding to the undercut portion. The method for producing a resin tank according to claim 1, 2, or 3.