JP3385556B2 - Injection molding method and injection mold for multi-blade vehicle for blower - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding method for a multiblade vehicle for blowers and an injection molding die for the multiblade vehicle used in this method.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, a multiblade for a blower has been used. This multi-wheeled vehicle 1 has a central plate 2 in which a boss (not shown) made of a metal cylinder is embedded in the central portion.
Both end surfaces of the outer peripheral portion and the rings 3 and 4 at both end portions are connected by a large number of blades 5 and 6. These blades 5 and 6 are arranged at intervals in the circumferential direction and extend in the axial direction, and the blade 5 on one side of the central plate 2 and the blade 6 on the other side are circumferentially arranged. The positions are shifted. Furthermore, the outer diameters of the outer peripheral surface of the central plate 2 and the outer peripheral surfaces that connect the outer peripheral surfaces of the blades 5 and 6 are equal, and these are formed in a cylindrical shape. The rings 3 and 4 are the outer peripheral surfaces of the central plate 2 and the blades 5 and 6. Is formed so as to slightly project from.

To mass-produce the above-mentioned multi-blade vehicle, as shown in each of FIGS. 6 to 8, an injection molding die is used for integral molding. As shown in FIG. 6, the injection mold can be detachably attached to a fixed mold 8 that is detachably fixed to a fixed side 7b of an injection molding machine 7 having an injection unit 7a, and a movable side 7c of the injection molding machine 7. It is composed of a movable mold 9 for fixing. As shown in FIGS. 7 and 8, in the fixed mold 8, a casing 11 is fixed to an inner end surface of the fixed mold body 10 facing the movable mold 9, and the front end side of the fixed mold 8 opens with a large diameter. A truncated cone-shaped recess is formed, a fixed insert 12 is provided in the center of the bottom surface of the casing 11, and a large number of blade forming grooves 12 a are formed on the outer periphery of the fixed insert 12.
Have a mutual spacing in the circumferential direction, over the entire axial length,
It is installed side by side.

In the movable mold 9, a frustoconical slider 14 is arranged on the surface of the movable mold body 13 facing the fixed mold body 10. The slider 14 is divided into four transverse fan-shaped divided pieces 15. Each divided piece 15 is held by the movable mold body 13 so as to engage with a rail (not shown) and slide in the radial direction. Further, in the slider 14, the outer peripheral surface 14a is brought into contact with the inner peripheral surface 11a of the casing 11 when the divided piece 15 is closed, the inner peripheral surface 14b is formed in a circular cross section, and notches for ring molding are formed at both ends thereof. 16 and 17 are provided in a ring shape.

A movable insert 18 is provided at the center of the movable mold body 13 so as to face the fixed insert 12, and a blade forming groove 18a is formed on the outer periphery of the movable insert 18 in the same manner as the blade forming groove 12a of the fixed insert 12. It is installed side by side.
A plurality of protruding pins 19 that move through the movable insert 18 in the axial direction are attached to the movable mold body 13 by a conventional means.

Further, the base parts of the four angular pins 20 are fixed to the fixed type main body 10, and the tip end side parts of these are insertable into the inclined holes 15a formed in each divided piece 15 of the slider 14, respectively. There is. As will be described later,
Blade forming groove 12 of fixed and movable nests 12 and 18
A draft is formed in each of a and 18a. In addition, reference numeral 22 in FIG. 7 denotes a boss of the multi-wheel vehicle 1.
Is fixed by being inserted into the motor shaft of the blower.

In order to perform injection molding of a multi-blade vehicle using the above-mentioned injection molding die, as shown in FIG. 8 (a), the fixed die 8 and the movable die 9 mounted on the injection molding machine are opened. With the protruding pin 19 retracted and the slider 14 open to the outer peripheral side, a boss (not shown) is inserted into the fixed insert 12, and the mold closing is started by the operation of the injection molding machine, and the movable mold 9 is fixed. Proceed toward 8. During the mold closing shown in FIG. 8B, the outer peripheral surface 14 a of the slider 14 of the movable mold 9 is fitted to the inner peripheral surface 11 a of the casing 11 of the fixed mold 8, and the angular pin fixed to the fixed mold 8. The tip end of 20 is fitted into the inclined hole 15a provided in the divided piece 15 of the slider 4 (see FIG. 7). In the state shown in FIG. 8B, the divided pieces 15 are separated in the circumferential direction of the slider 4.
Further, when the movable mold 9 advances, the angular pin 20
Is inserted deeply into the inclined hole 15a, and the divided piece 1
5 moves to the center side of the movable mold 9, and when the mold closing is completed as shown in FIG. 8C, the divided pieces 15 are in close contact with each other and the slider 14 has a truncated cone shape, and its outer peripheral surface 14a is fixed. Mold 8
While closely contacting the circumferential surface 11 a of the casing 11, a gap for molding the central plate is formed between the tip surface of the fixed insert 12 and the tip surface of the movable insert 18.

Next, a molten resin is injected from the injection molding machine into the cavity formed by the fixed mold 8 and the movable mold 9, and the resin is cooled to mold the substantially cylindrical multi-wheel vehicle 1. , The mold closed state shown in FIG. When the movable mold 9 is retracted from this state to perform mold opening, the movable mold 9 is separated from the bottom surface of the casing 11 of the fixed mold 8 and the front end surface of the fixed insert 12, and the angular pin 20 is interlocked with the retraction of the movable mold 9. Is extracted from the divided pieces 15 of the slider 14, so that the molded multi-blade wheel 1 is held by the movable mold 9 during the mold opening as shown in FIG. 8E.

When the movable mold 9 is further retracted, the fixed insert 12 is separated from the multi-blade wheel 1, the angular pin 20 is separated from the split piece 15, and subsequently the slider 14 is separated from the casing 11 of the fixed mold 8. The mold opening completion state shown in FIG. In this state, the plurality of projecting pins 19 project from the movable nest 18 and push the central plate 2 of the multi-wheel vehicle 22. Therefore, the multi-wheel vehicle 1 is separated from the inner end surface of the movable mold main body 13 and the movable nest 18 and separated from the movable mold 9, and is in a protruding complete state as shown in FIG. 8 (g).
After that, the multi-wheel vehicle 1 is obliquely taken out from the portion surrounded by the fixed mold 8 and the movable mold 9. After that,
The projecting pin 19 is retracted, the mold closing state shown in FIG. 8A is returned, and the above-described operation is repeated to mass-produce the multi-wheel vehicle 1.

[0010]

However, in the above-described conventional injection molding method for a multiblade for a blower, as shown in FIGS. 9 (d) and 9 (e).
As shown in FIG. 5, when the mold is opened from the mold closed state, the ring 3 on the fixed mold 8 side of the molded multi-blade 1 bites on the bottom surface of the casing 11 in the middle of the process, and the multi-wheel 1 is fixed to the fixed mold. Type 8
And the ring 14 on the movable mold 9 side of the multi-wheel vehicle 1 is separated from the slider 14 by the cutout recess 17 of the slider 14.
Since the multi-blade wheel 1 becomes a defective product and the inside of the slider 14 is difficult to see from the outside, the broken pieces 4 of the ring 4 are broken.
There is a problem that a remains in the slider 14 of the movable mold 9, the mold is closed without noticing the broken pieces 4a, and the movable insert 18 and the like are damaged.

Therefore, as shown in FIG. 10, a draft is provided so that the blade width on the side of the central plate 2 becomes wider with reference to the tips of the blades 5 and 6 of the multi-wheel vehicle 1. That is, 6/1000 on the fixed mold side and 5/1000 on the movable mold side.
By providing gradients having different rates on the bottoms of the blade forming grooves 12a and 18a, the blade 5 on the fixed mold side can be easily removed from the mold. However, during injection molding, the molten resin flows from the portion forming the central plate to the fixed mold side before the movable mold side, and the multi-wheel vehicle 1 molded on the fixed mold side is easily taken. The above problems can hardly be solved.

The present invention solves the above-mentioned problems,
The molded multi-blade is surely left on the movable mold side, no defective products such as the ring on the movable mold side is damaged, and the broken pieces of the ring remain on the slider of the movable mold. An object of the present invention is to provide an injection molding method for a multi-blade vehicle for blowers and an injection molding mold used in this method, which can prevent the movable nest from being damaged.

[0013]

According to a first aspect of the present invention, there is provided an injection molding method for a blower multi-blade vehicle as described above, wherein the slider is fixed to an annular recess formed in an axially central portion of an inner peripheral surface of the slider. The mold and the movable mold are closed, and a part of the synthetic resin injected into the cavity surrounded by the casing, slider and movable mold body is filled, and the outer peripheral portion of the center plate is projected to the outer peripheral side of the blade. Then, the movable die is moved in the axial direction away from the fixed die, and the slider is interlocked with this movement to open the slider.At the beginning of die opening, the outer periphery of the central plate fits into the recess of the slider, The molded multi-blade is fastened to the movable mold side.

According to a second aspect of the present invention, in the injection molding die for a multi-blade vehicle for blowers as described above, the slider is fixed to the inner peripheral surface of the slider in an axially central portion in an annular shape upon completion of mold closing. A concave portion for molding the outer peripheral portion of the central plate is formed so as to face the gap for molding the central plate between the tip surfaces of the movable inserts.

Further, the invention of claim 3 is, in the injection mold of the multiblade for a blower according to claim 2, at the bottom of a large number of blade molding grooves arranged in parallel on the outer periphery of the fixed insert,
Forming a draft that increases on the center plate side with respect to the blade tip on the fixed mold side, at the bottom of many blade forming grooves arranged side by side on the outer periphery of the movable insert, the blade base end on the center plate side As a reference, a draft is formed which becomes smaller toward the tip of the blade of the movable nest and has a lower rate than the draft of the blade of the fixed nest.

[0016]

According to the first aspect of the present invention, there is provided an injection molding method for a multiblade for a blower, wherein an annular recess formed on the inner peripheral surface of the slider is
After the mold closing is completed, the cavity formed by the fixed mold and the movable mold is filled with a part of the injected synthetic resin, and the outer peripheral part of the center plate is projected to the outer peripheral side of the blade, so that the mold opening begins. , The movable mold moves in the axial direction away from the fixed mold, the slider opens in conjunction with this movement, and when the inner peripheral surface of the slider separates from the outer peripheral surface of the molded multi-wheel vehicle, the center of the recess Since the outer peripheral portion of the plate is fitted, the outer peripheral portion forcibly holds the multi-wheel vehicle on the movable mold side.

Therefore, by continuing to open the mold, the multi-wheel vehicle is not left on the fixed mold side, but reliably remains on the movable mold side and moves with it, without damaging the ring. Can be demolded from the fixed mold, and after the mold opening is completed, the multi-impeller can be demolded from the movable mold to eliminate the occurrence of defective products, and the broken pieces of the ring remain in the slider to damage the movable nest. Can be prevented.

In the injection molding die for a multiblade for a blower according to the second aspect of the present invention, a concave portion is formed in the axial center portion of the inner peripheral surface of the slider provided on the movable die. When the slider is closed when the mold is closed, an annular recess is formed on the inner peripheral surface of the slider, and the injection molding method for a multi-blade vehicle according to claim 1 can be performed.

According to a third aspect of the injection molding die for a blower multi-blade, a draft formed at the bottom of the blade forming groove provided in the fixed insert and the movable insert has a blade on the fixed die side in the movable insert. With the tip as the reference, the fixed insert was formed with the blade base end on the side of the center plate as the reference, and the draft of the movable insert was set to be lower than the draft of the fixed insert. The blades on the fixed mold side of the car are easily removed from the mold, and the multi-blade wheel is likely to remain on the movable mold side.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described. 1 and 2 show a multiblade for a blower obtained by an injection molding method according to an embodiment of the present invention,
In this multi-wheel vehicle 1, the outer peripheral portion 2a of the central plate 2 is projected in an annular shape on the outer peripheral sides of the blades 5 and 6. That is,
Assuming that the outer diameter of the central plate 2 is A, the outer diameter connecting the outer circumferences of the blades 5 and 6 is B, and the outer diameters of the rings 3 and 4 provided at both ends are C, the relationship of B <A <C is obtained. To do. In addition,
A, B and C are all diameters.

Specifically, in the multi-blade wheel 1 with B = 135 mm, A = B + 2.0 mm to 4.0 mm, preferably 3.0.
mm to 4.0 mm. This means that, as shown in FIG.
When the thickness of the ring 3 on the fixed mold side is 5.0 mm or more, when the angle of inclination of the angular pin 20 with respect to the axial direction of the injection mold is 15 °, the movement amount of the slider 14 becomes tan15 ° = 0.268. The outer diameter 2a of the central plate 2 may be 1.33 mm (about 1.5 mm) in radius, and the outer diameter may be set to 3 mm or more in diameter. However, since there is interference with the casing 11 of the fixed mold 8, C = B + 6 mm
And

Therefore, in the slider 14 of the injection mold of this embodiment, the slider 14 is located at the central portion in the axial direction, and
1.0 mm to 2.0, which is annular when the split piece 15 is closed
The recess 23 is dug into the inner peripheral surface to a depth of about mm.

Further, as shown in FIGS. 1, 2 and 3,
A draft is provided so that the blade width on the side of the central plate 2 is wide with reference to the tip of the blade 5 on the fixed mold side of the multi-wheel vehicle 1, and the blade width on the side of the tip is based on the base end on the side of the central plate 2. A draft is provided so as to be narrow, and these gradients are set to 6/1000 on the fixed mold side and 5/1000 on the movable mold side. Therefore, the draft is formed at the bottom of the blade forming grooves 12a, 18a of the fixed insert 12 and the movable insert 18. 1 to 3, the same reference numerals as those in FIGS. 5 to 10 denote corresponding parts, and the multi-blade wheel 1 and the injection molding die according to this embodiment have the same configurations as those described above. Is the same as the conventional multi-blade and injection molding die shown in each of FIGS. 5 to 10.

Next, an injection molding method for a multi-blade vehicle according to an embodiment of the present invention will be described. Using the injection molding die shown in FIG. 3, a fixed die 8 is detachably fixed to the fixed side of the injection molding machine, and a movable die 9 is detachably fixed to the movable side. The steps from the mold closing to the mold closing are performed in the same manner as the conventional injection molding method shown in FIG. 8 and described above.

When the molten resin is injected into the cavity formed by the fixed mold 8 and the movable mold 9 in the mold closing completed state, a part of this resin is the inner peripheral surface 14b of the slider 14 of the movable mold 9. The outer peripheral portion 2a of the center plate 2 of the multi-wheel vehicle 1 that is also filled and molded in the annular recess 23 formed in
Project to the outer peripheral side of the blades 5 and 6 (see FIGS. 3 and 4).
(See (d)). Further, since the blade forming grooves 12a and 18a of the fixed and movable inserts 12 and 18 are provided with slopes having different rates at the bottoms, the drafts described above with reference to FIGS. , 6 are formed. Therefore, the molten resin flows from the center plate 2 side to the ring 3 side on the fixed mold 8 side, and before the ring 4 on the movable mold 8 side.
Flowing to the side.

After the injected resin is cooled, the movable mold 9 is retracted from the mold closed state shown in FIG. 4 (d), and the molded multi-blade wheel 1 is shaped as shown in FIGS. 4 (e) and 4 (e). As shown in FIG. 3, when the angular pin 20 fixed to the fixed mold 8 and separated from the bottom surface of the casing 11 of the fixed mold 8 and the tip surface of the fixed insert 12 is pulled out from the divided piece 15 of the slider 14, The respective divided pieces 15 of the slider 14 move radially outward in conjunction with the movable mold 9, and the outer peripheral portions of the rings 3, 4 of the multi-blade wheel 1, the outer peripheral surfaces of the blades 5, 6 and the outer peripheral portion 2a of the center plate 2 are moved. Are the inner peripheral surface 14 of the slider 14, respectively.
Away from a, the tip end surface of the ring 4 of the multi-wheel vehicle 1 is in a state of being bonded and held to the movable mold body 13 of the movable mold 9.

At this time, the blade 5 on the fixed mold 8 side of the multi-wheel vehicle 1 is pulled out from the blade forming groove 12a of the fixed insert 12, and the blade 5 on the fixed mold 8 side is 6 / A draft of 1000 is formed and the movable mold 9
The blade 6 on the side is formed with a draft of 5/1000 that decreases toward the movable mold 9 side with respect to the base end on the side of the central plate 2. As described above, the synthetic resin is formed on the ring 3 on the side of the fixed mold 8. Since it flows to the ring 4 side of the movable mold 8 side earlier than the side, the central ring 2 side may not have a step like the conventional one, so that the blade 5 on the fixed mold 8 side can be easily removed. The multi-wheel vehicle 1 is likely to remain on the movable mold 9 side.

Further, the annular recess 2 provided in the slider 14
When the outer peripheral surface 2a of the central plate 2 is embedded in the mold 3, the mold opening is started, and when the outer peripheral surface of the multiblade 1 is separated from the inner peripheral surface of the slider 14, the outer peripheral surface of the central plate 2 is inserted into the recess 23 of the slider 14. Since the portion 2a is fitted, the multi-wheel vehicle 1 is forcibly retained on the movable mold 9 side by the outer peripheral portion 2a. Therefore, the molded multi-blade wheel 1 is reliably retained on the movable mold 9 side without being taken by the fixed mold 8 side.

From the state in which the mold is being opened as shown in FIG.
When the movable mold 9 is further retracted, the fixed insert 12 is separated from the multi-blade wheel 1, the angular pin 20 is separated from the split piece 15, and the slider 14 is separated from the casing 11.
The mold opening completion state shown in (f) is reached. After opening the mold,
Similar to the conventional injection molding method described above, the multi-blade wheel 1 is separated from the inner end surface of the movable mold main body 13 and the movable nest 18 by the projection of the projecting pin, and the multi-blade wheel 1 is taken out of the injection molding die to project the projecting pin. The multi-blade vehicle is mass-produced by pulling in and repeating the above-mentioned operation.

[0030]

As described above, in the injection molding method for a blower multi-blade vehicle according to the first aspect of the present invention, the mold closing is completed in the annular recess formed in the inner peripheral surface of the slider, and the fixed mold is formed. The cavity formed by the movable mold was filled with a portion of the synthetic resin injected, and the outer peripheral portion of the center plate was projected to the outer peripheral side of the blade, so the movable mold was fixed at the beginning of mold opening. The slider moves in the axial direction away from the slider, the slider opens in conjunction with this movement, and when the inner peripheral surface of the slider separates from the outer peripheral surface of the molded multi-blade, the outer peripheral portion of the central plate fits in the recess. Therefore, the outer peripheral portion forcibly holds the multi-wheel vehicle on the movable die side.

Therefore, by continuing the mold opening, the multi-wheel vehicle is not left on the fixed mold side, but remains on the movable mold side and moves with it, without damaging the ring. Can be demolded from the fixed mold, and after the mold opening is completed, the multi-impeller can be demolded from the movable mold to eliminate the occurrence of defective products, and the broken pieces of the ring remain in the slider to damage the movable nest. Can be prevented.

In the injection molding die for a multiblade for a blower according to the invention of claim 2, a simple process is added to form a recess in the axial center of the inner peripheral surface of the slider provided on the movable die. Thus, when the slider is closed when the mold is closed, an annular recess is formed on the inner peripheral surface of the slider, and the injection molding method for a multi-wheel vehicle according to claim 1 can be performed.

Further, in the injection molding die for a multi-blade for a blower according to claim 3, the draft is provided at the bottom of the blade forming groove provided in the fixed insert and the movable insert, and the movable insert has a fixed mold side. With the blade tip of as a reference, the fixed nest is formed with the blade base end on the center plate side as a reference,
Since the draft of the movable insert is lower than the draft of the fixed insert, the blades on the fixed die side of the molded multi-blade are well removed at the start of mold opening, and the multi-blade is movable. There is an effect that it easily remains on the mold side.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a blower multi-blade obtained by an injection molding method according to an embodiment of the present invention.

2 is a vertical cross-sectional explanatory view of the multi-blade for blower of FIG.

FIG. 3 is a partial vertical sectional view showing an injection molding die of a multiblade for a blower according to an embodiment of the present invention.

FIG. 4 is an explanatory view showing a main part of an injection molding method for a multiblade for a blower according to an embodiment of the present invention.

FIG. 5 is a schematic perspective view of a multiblade for a blower obtained by a conventional injection molding method.

FIG. 6 is a schematic front view of an injection molding machine equipped with an injection molding die for molding the multi-blade for a blower shown in FIG.

FIG. 7 is a partial vertical cross-sectional view showing an injection mold of a conventional multi-blade for a blower.

FIG. 8 is an explanatory view showing, in the order of steps, an injection molding method for a conventional multiblade for a blower.

FIG. 9 is an explanatory view of problems caused by the injection molding method of FIG.

FIG. 10 is an explanatory view of a draft of a conventional multi-blade for a blower.

[Explanation of symbols]

1 multi-wheeled vehicle 2 Central plate 2a outer periphery 3,4 ring 5,6 blade 7 injection molding machine 8 Fixed mold 9 movable mold 11 casing 12 fixed nesting 12a Blade forming groove 14 Slider 15 pieces 16,17 Notches for ring molding 18 movable nesting 18a Blade forming groove 20 Angular Pin 23 recess

Continuation of front page (56) Reference JP-A-3-43223 (JP, A) JP-A-3-43239 (JP, A) JP-A-57-91225 (JP, A) JP-A-60-90727 (JP , A) Actual development 4-102823 (JP, U) Actual development 60-114818 (JP, U) Actual development 60-117116 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB) (Name) B29C 45/00-45/84

Claims (3)

(57) [Claims] 1. A stationary mold provided with a stationary insert in a central portion of a casing, and a movable insert located in a central portion of an inner end surface of the movable insert main body and an outer peripheral side of the movable insert in a movable insert main body. A movable mold provided with a slider composed of a plurality of divided pieces that move to a mold, and a synthetic resin is injected into a cavity surrounded by the casing, the slider fitted in the casing, and the movable mold body. A center plate formed by the gap between the tip surfaces of the inserts,
In the injection molding method of a multiblade for a blower, which integrally molds a large number of blades on both sides of the central plate along the circumferential direction, and a ring connecting the tips of these blades, the inner peripheral surface of the slider The annular recess formed in the central portion of the axial direction is filled with a part of the synthetic resin injected into the cavity, and the outer peripheral portion of the central plate is projected toward the outer peripheral side of the blade, and then the movable metal The mold is moved in the axial direction away from the fixed mold, and the slider is interlocked with this movement to open the slider. An injection molding method for a multi-blade for a blower, characterized by being fastened to a movable mold side. 2. A fixed mold having a fixed insert in the center of the casing, and a movable insert located at the center of the inner end surface of the movable insert and a movable insert, and a radial insert in the outer periphery of the movable insert. A movable die provided with a slider composed of a plurality of divided pieces that move to each other, and the two inserts are formed to have a length such that a gap for forming a central plate is formed between the tips when the molds are closed. Injection of a blower multi-blade vehicle in which a large number of blade forming grooves along the circumferential direction are arranged side by side on the outer peripheral portion of the insert, and notches for ring forming are formed at both axial ends of the inner peripheral surface of the slider. In the molding die, an outer peripheral portion of the central plate, which is annular at the central portion of the inner peripheral surface of the slider when the mold closing is completed, and which faces the gap for molding the central plate between the tip surfaces of the both inserts. Recess for molding A multi-blade injection molding die for a blower, characterized in that a portion is formed. 3. The movable insert of the movable insert is formed with drafts that increase on the central plate side with respect to the blade tip of the fixed mold on the bottom of a large number of blade forming grooves arranged side by side on the outer periphery of the fixed insert. At the bottom of a large number of blade forming grooves arranged side by side on the outer periphery, with the blade base end on the side of the center plate as the reference, it becomes smaller toward the tip of the blade of the movable nest, and at a lower rate than the draft of the blade of the fixed nest 3. An injection molding die for a multiblade for a blower according to claim 2, wherein each of the drafts has the following draft.