JPH11291257A - Diameter expansible core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly mold the inner periphery of the rubber ring mounting groove of the pipe receiving port, part for example, of a pipe joint or a drain measure. SOLUTION: In a stretchable core 7, the T-shaped fitting part 8A of a fan- shaped core 8 is fitted in the guide dovetail grooves 10 of a diameter retractable guide 6 of which the diameter is reduced from the root end part thereof to the leading end part thereof in a freely slidable manner and both sides of a trapezoidal core 9 are pressed by both sides of the fan-shaped cores 8 and expansion rods 12 are holes 13 between the guide slopes 11 and the trapezoidal cores 9 to apply outward expansion force to the trapezoidal cores 9 and fan- shaped cores 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expansion / reduction core used mainly for forming a rubber ring mounting groove in a receiving portion of a pipe joint or a drainage basin.

[0002]

BACKGROUND OF THE INVENTION For example, a groove for mounting a rubber ring for ensuring airtightness is formed in a receiving portion of a pipe joint. In order to form such a receiving portion, a rubber ring mounting groove forming portion is provided in the inner portion of the receiving portion. However, the rubber ring mounting groove of the formed receiving portion becomes an undercut portion. The inner mold cannot be pulled out from the receptacle. Therefore, a core having an enlarged or reduced diameter is arranged in the rubber ring mounting groove forming portion of the inner mold of the receiving portion, the enlarged or reduced diameter core is set in an enlarged state at the time of molding, and when the inner mold is pulled out from the molded product after molding, the There has been provided a mold having a system in which a core having an increased or reduced diameter is stored in an inner mold in a reduced diameter state.

[0003]

2. Description of the Related Art Conventionally, as shown in FIG.
6) is provided. The expansion and contraction core (46) is an expansion and contraction diameter guide.
(47), a fan-shaped core (48), a trapezoidal core (49), the expanding and contracting diameter guide (47) has a tapered shape in which the diameter decreases from the root end to the tip end, and the peripheral surface has The guide dovetail groove (50) of the sector core (48) and the guide dovetail groove (51) of the trapezoid core (49) are provided alternately, and the sector core is provided in the guide dovetail (50, 51). (48)
And T-shaped fitting portions (48A, 49A) formed at the root end of the trapezoid core (49), respectively, are slidably fitted. In the enlarged / reduced diameter core (46) having the above configuration, at the time of molding, the fan-shaped core (48) and the trapezoidal core (49) are located at the root end of the enlarged / reduced diameter guide (47). When the inner die is pulled out, the expanding / reducing guide (47) is slid so that the fan-shaped core (48) and the trapezoidal core (49) are attached to the distal end of the expanding / reducing guide (47). And brought into the reduced diameter state shown in FIG.

[0004]

SUMMARY OF THE INVENTION The above-mentioned conventional core having an enlarged or reduced diameter.
(46), the T-shaped fitting portion (48A, 49A) of the sector core (48) and the trapezoid core (49) and the guide dovetail groove (50,
51) and there is some backlash between
As shown in Figure 3, the fan-shaped core (48) and trapezoidal core (49) in the expanded state
Thus, there is a problem that the circumference formed by the above becomes uneven, and a rubber ring mounting groove having a smooth inner circumference cannot be obtained.

[0005]

As a means for solving the above-mentioned conventional problems, the present invention has a tapered shape in which the diameter decreases from the root end to the tip, and the guide dovetail groove (10) is formed on the peripheral surface. ) And a guide slope (11) alternately provided with an enlarged / reduced diameter guide (7), a fan-shaped core (8) formed with a T-shaped fitting part (8A) at the root end, and a trapezoidal core (9) And the guide slope
The inclination of (11) is set to be steeper than the inclination of the guide dovetail groove (10), and the T-shaped fitting portion (8A) of the sector core (8) is guided by the guide of the expanding / reducing guide (7). It is slidably fitted in the dovetail groove (10),
The trapezoid core (9) is slidably disposed on the guide slope (11), both sides of which are pressed by both sides of the sector core (8). An insertion hole (13) for inserting an overhanging rod (12) is formed between the trapezoidal core (9) and the guide slope (11) at a root end of the overhanging rod (12). By pushing the trapezoidal core (9) into the insertion hole (13), an overhanging force is applied to the trapezoidal core (9).
An object of the present invention is to provide an expanding / reducing core (6) in which the fan-shaped core (8) is also provided with an outward projecting force via (9). In particular, in the present invention, the expanding / reducing core (6) is mounted on the inner mold (2) of the fitting for forming the rubber ring mounting groove (45) of the fitting (44) of the pipe joint. (12), a sliding plate (14, 15, 16) is in communication with the expanding / reducing guide (7) of the expanding / reducing core (6) and the inner mold (2) of the receiving part, respectively. Dynamic plate (14,15,1
The overhanging rod (12) is inserted into and pulled out of the expanding / reducing core (6) through 6), and the expanding / reducing diameter guide (7) slides in the core expanding / reducing direction. The inner mold (2) of the receiving portion is pulled out from the receiving portion (44) inserted and molded into the mold (1), and the sliding plate (14) of the expanding / reducing guide (7) is attached to the overhanging rod (44). 12)
The extension plate (12) slides by being pulled and pushed by the slide plate (16) by contacting the slide plate (16) with a predetermined play. The sliding plate (15) is also the sliding plate (16) of the overhanging rod (12).
It is desirable to adopt a configuration that slides by being pushed or pulled by the arm.

[0006]

The expansion / reduction guide (7) is slid in the forward and reverse directions with respect to the sector core (8) and the trapezoid core (9), so that the sector core (8) and the trapezoid core (9) are slid. ) Means expanding or contracting. In the expanded state, that is, during molding, the sector corresponding to the inner periphery of the rubber ring mounting groove (45) is formed by the sector core (8) and the trapezoid core (9). At this time, when an overhanging rod (12) is pushed into an insertion hole (13) formed between the trapezoid core (9) and the guide slope (11) of the expansion / contraction guide (7), the trapezoid Child (9)
Is provided with an overhanging force to the outside, and the overhanging force is also applied to the fan-shaped core (8) via the trapezoidal core (9), so that the T-shape of the fan-shaped core (8) is Rattling between the fitting portion (8A) and the guide dovetail groove (10) of the expanding / reducing guide (7) is eliminated, and the fan-shaped core (8) and the trapezoidal core (9) are formed. There are almost no irregularities on the circumference.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to an embodiment shown in FIGS. 1 to 11. An injection mold (1) includes an inner mold (2) for a receiving portion, a remaining inner mold (3), and an inner mold (3). An inner die (2) having an outer die (4), and an inner core (6) for forming a rubber ring mounting groove is mounted in an inner space (5) of the inner die (2).

As shown in FIGS. 3 and 4, the expanding / reducing core (6) comprises an expanding / reducing diameter guide (7), a sector core (8) and a trapezoidal core (9). (7) has a tapered shape in which the diameter decreases from the root end to the tip, and guide dovetails (10) and guide slopes (11) are alternately formed on the peripheral surface, and as shown in FIG. The slope of the guide slope (11) is set to be steeper than the slope of the guide dovetail groove (10),
A T-shaped fitting portion (8A) formed at the root end of the sector core (8) is slidably fitted in the guide dovetail groove (10), and is fitted to the guide slope (11). The root edge of the trapezoid core (9) is slidably in contact. In this state, both sides of the trapezoid core (9) are fan-shaped cores
Both sides of (8) are pressed from the outside and are prevented from jumping out. An insertion hole (13) for inserting an overhanging rod (12) is formed between the trapezoidal core (9) and the guide slope (11) at the root end of the expansion / contraction guide (7). I have. A tapered portion (12A) is formed at the tip of the overhang bar (12).

[0009] The inner mold (2) of the receiving portion has a tapered connecting portion (17).
Connected to the sliding plate (14) through the core (6)
The expansion / contraction guide (7) is connected to the sliding plate via the connecting rod (18).
(15), and the overhang bar (12) is connected from the sliding plate (16).

The sliding plates (14, 15, 16) are slidably mounted on a base (19), and are guided left and right by sliding frames (20, 20). As shown in FIGS. 5 and 6, the slide plate (16) of the overhang bar (12) is provided with a bracket (2).
The connecting plate (22) is connected via 1), and the connecting plate (22)
A cross beam (23) is attached to the tip of the cross beam, and piston rods (25, 2) of hydraulic cylinders (24, 24) are attached to both ends of the cross beam (23).
5) is connected.

As shown in FIG. 5 and FIG.
A connecting plate (26) is connected to the sliding plate (15) of (6), and a pair of left and right pins (27, 27) is erected at the end of the connecting plate (26). The pins (27, 27) are slidably fitted in elongated holes (28, 28) provided at the bottom of the slide plate (16) of the overhang bar (12).

As shown in FIG. 2 and FIG.
The sliding plate (14) of (2) communicates with the leading sliding plate (30) through a pair of left and right connecting plates (29, 29) and a connecting pipe (29A). ) Is other sliding plate
Like (14, 15, 16), it is slidably installed on the base (19) while being guided by the sliding frames (20, 20).

The sliding plate (15) of the core (6) and the sliding plate (16) of the overhang bar (12) are connected to pins (27, 27),
Locking hole (3) of connecting plate (26) connected through slot (28,28)
In (1) there is an electromagnetic cylinder (33) mounted in the base (19)
5 and 6 (see FIGS. 5 and 6), and furthermore, the sliding plate (14) of the inner mold (2) and the leading sliding plate (30) are connected to each other. The pin (35) of the electromagnetic cylinder (36) mounted in the base (19) is engaged with the lock hole (34) of the connecting plate (29, 29) to be connected (FIG. 2). ,
See FIG. 6).

As shown in FIGS. 5 and 6, an electromagnetic cylinder (39) in which a pin (38) is engaged with a lock hole (37) of the sliding plate (16) is inserted into the connecting plate (26). Each connecting plate (29, 29) has a sliding plate (15) as shown in FIGS.
When the pin (41) is engaged with the lock hole (40) of the electromagnetic cylinder (4
2) is interpolated.

In the above configuration, the overhanging rod (1
2) Guide slope of trapezoid core (9) and expansion / contraction guide (7)
(11) is inserted into the insertion hole (13) formed between the trapezoidal core (9) and the fan-shaped core (8) through the trapezoidal core (9). And the circumference formed by the sector core (8) and the trapezoid core (9), that is, the molding (4
The rubber ring mounting groove (45) of the receiving portion (44) of (3) has almost no irregularities in the inner peripheral molding portion, and the rubber ring mounting groove (45) having a smooth inner periphery is molded.

After the molding, the hydraulic cylinder (24) is operated from the state shown in FIGS.
The slide plate (16) is slid in the direction shown by the arrow (a) in FIG. 5 (forward) through 2) to the state shown in FIG. 8, and the overhanging rod (12) is pulled out from the core (6). At this time, the connecting plate (26) of the sliding plate (15) of the core (6), the sliding plate (14) of the inner mold (2) of the receiving part, and the leading sliding plate (30) are connected. The pair of right and left connecting plates (29, 29) are locked so that the pins (32, 35) of the electromagnetic cylinder (33, 36) engage with the respective lock holes (31, 34) so that they do not slide. ing.

When the sliding plate (16) comes to the position of FIG.
When the overhang bar (12) is completely withdrawn from the core (6), a pin of the connecting plate (26) is attached to the rear end of the slot (28, 28) of the slide plate (16). (27) is located at the same time as the sliding plate (1
The position of 6) is detected by a photoelectric sensor or the like, and the electromagnetic cylinder (3
3) is actuated to release the pin (32) of the electromagnetic cylinder (33) from the lock hole (31) of the connecting plate (26) to release the locking of the connecting plate (26) as shown in FIG. I do.

Thus, the connecting plate (26) of the sliding plate (15) becomes slidable, and is pulled by the sliding plate (16) through the pins (27, 27) and the elongated holes (28, 28). 8 Slide in the direction of arrow a, and the expanding / reducing guide (7) of the expanding / reducing core (6)
(15) slides in the same direction via the connecting rod (18), and the T-shaped fitting portion (8A) of the sector core (8) relatively
Slide the guide dovetail groove (10) of (7) in the tip direction, and
(9) is pushed by the sector core (8) and slides on the guide slope (11) of the expansion / contraction guide (7).
(6) shifts from the expanded state shown by the dotted line to the reduced state shown by the solid line as shown in FIG. 10, and the sliding plate (16) shown in FIG.
Abuts on the leading sliding plate (30), and when the expanded / reduced diameter core (6) is completely reduced in diameter, it is completely removed from the rubber ring mounting groove (45) of the formed receiving portion (44). . In this state, the position of the sliding plate (16) is detected by a photoelectric sensor or the like to operate the electromagnetic cylinder (36), and the pin (35) of the electromagnetic cylinder (36) is operated.
9 is removed from the lock hole (34) of the connecting plate (29, 29).
The lock of the connecting plates (29, 29) is released as shown in FIG.

The sliding plate (16) pulls the sliding plate (15) as described above, and further leads the sliding plate (30).
Press and slide. Then the leading sliding plate (30)
As shown in FIG. 11, the sliding plate (14) is pulled through the connecting plates (29, 29) unlocked as described above, and as shown in FIG. ).

In order to set the inner mold (2) of the receiving portion into the mold, the electromagnetic cylinder (39) of the connecting plate (26) is operated in the state shown in FIG. The pin (41) is engaged with the lock hole (40) of the sliding plate (15) by engaging the lock hole (37) of (16) and operating the electromagnetic cylinder (42) of each connecting plate (29, 29). Engage. Thus, the connecting plate (26) and the sliding plate (16) and the connecting plate (29, 29) and the sliding plate
With the (15) locked, the hydraulic cylinder (24) is operated to operate the connecting plate (26) and the sliding plate (16) via the connecting plate (22),
And slide the sliding plate (14) through the connecting plates (29, 29) and the sliding plate (15) and the leading sliding plate (30) in the direction of arrow B (rearward). The socket inner mold (2) is set in the mold while the child (6) is kept in the reduced diameter state.

Next, the electromagnetic cylinder (4) of the connecting plate (29, 29)
2) Activate the pin (41) to lock the slide plate (15)
Pull out from (40), connect plate (29,29) and slide plate (15)
And then slide the sliding plate (16) and the sliding plate (15) together in the direction of the arrow B.
(6) is in the expanded state.

Finally, the electromagnetic cylinder (39) of the connecting plate (26) is operated to lock the pin (38) with the lock hole (37) of the sliding plate (16).
From the connecting plate (26) and the sliding plate (16), and the sliding plate (16) is further slid to move the overhang rod (12) to the core (6). Press into the insertion hole (13) between the guide slope (11) of the expansion and contraction diameter guide (7) and the trapezoid core (9), and remove it to the trapezoid core (9) and the sector core (8). The electromagnetic cylinder (36) is actuated to protrude the pin (35) upward, and the pin (35) is engaged with the lock hole (31) of the connecting plate (26). Then, the sliding plate (15) is locked. In this way, the injection mold (1) returns to the standby state shown in FIGS. 1, 2 and 5.

[0023]

According to the present invention, there is provided an enlarged / reduced-diameter core for forming a rubber ring mounting groove at a pipe receiving portion of a pipe joint or a drainage basin.
The projecting rod is pushed into the insertion hole between the guide slope of the expansion / contraction guide and the trapezoidal core to apply an outward projecting force to the trapezoidal core, and further to the fan-shaped core via the trapezoidal core. Almost no irregularities are formed on the circumference formed by the core and the trapezoidal core, so that a rubber ring mounting groove having a smooth circumference can be formed.

[Brief description of the drawings]

 1 to 11 show a specific example of the present invention.

FIG. 1 is an explanatory view of a plane cross section.

FIG. 2 is an explanatory side sectional view (central cross section).

FIG. 3 is an exploded perspective view of an enlarged / reduced diameter core.

FIG. 4 is an explanatory diagram of an expanded state.

FIG. 5 is an explanatory side sectional view (end cross section).

FIG. 6 is an explanatory view of a connection plate arrangement.

FIG. 7 is an explanatory view of an angle between a guide groove and a guide slope.

FIG. 8 is an explanatory side sectional view of a state in which the overhang bar is pulled out.

FIG. 9 is an explanatory diagram of a sectional side view of a reduced diameter state.

FIG. 10 is an explanatory view of a reduced diameter state.

FIG. 11 is a sectional side view of the die in the receiving portion in a state where the die is pulled out;
4 shows a conventional example.

FIG. 12 is an exploded perspective view of a core having an enlarged or reduced diameter.

FIG. 13 is an explanatory diagram of an expanded state.

FIG. 14 is an explanatory diagram of a reduced diameter state.

[Explanation of symbols]

 1 Injection molding die 2 Inner part of receiving part 6 Core with expansion and contraction 7 Expansion and contraction diameter guide 8 Fan-shaped core 8A T-shaped fitting part 9 Trapezoid core 10 Guide dovetail groove 11 Guide slope 12 Overhang rod 13 Insertion holes 14,15, 16 Sliding plate 43 Molded product 44 Receptacle 45 Rubber ring mounting groove

Claims (3)

[Claims] An enlarged / reduced diameter guide having a tapered shape in which a diameter is reduced from a root end to a tip, and a guide dovetail groove and a guide slope are alternately provided on a peripheral surface, and a T-shaped fitting portion. It is composed of a fan-shaped core formed at the root end and a trapezoidal core, and the inclination of the guide slope is set to be steeper than the inclination of the guide dovetail groove, and the T-shaped fitting portion of the fan-shaped core is The trapezoid core is slidably fitted in the guide dovetail groove of the expansion / contraction guide, and the trapezoid core is slidably disposed on the guide slope, and both sides of the core are pressed by both sides of the sector core, Further, an insertion hole for inserting an overhanging rod is formed between the trapezoidal core and the guide slope at a root end portion of the expanding / contracting diameter guide, and the overhanging rod is pushed into the insertion hole to form the trapezoidal center. An overhanging force is applied to the outer core, and the outer core is also applied to the fan-shaped core through the trapezoidal core. Scaling wherein the overhang force is applied to 径中Ko 2. The expansion / reduction core is mounted on an inner mold of a receiving portion for forming a rubber ring mounting groove in a receiving portion of a pipe joint, the overhanging rod, the expanding / reducing diameter guide of the expanding / reducing core, and Sliding plates are connected to the inner molds of the receiving portions, respectively. The overhanging rod is inserted into and pulled out of the expanding / reducing core through the sliding plate, and the expanding / reducing guide is used for expanding / reducing the core. The core according to claim 1, wherein the core is slid in the radial direction of the core and the inner mold of the socket is pulled out from the socket formed by being inserted into a mold. 3. The sliding plate of the expanding / reducing guide is slid by being pulled and pushed by the sliding plate of the overhanging bar by contacting the sliding plate of the overhanging bar with a predetermined play. 3. The core according to claim 2, wherein the sliding plate of the inner mold of the receiving portion also slides by being pushed or pulled by the sliding plate of the overhang bar.