JP2636548B2 - Molten resin supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten resin supply device, and more particularly to a hollow portion formed on a contact surface when a second mold is brought into contact with a first mold of an injection molding machine. The present invention relates to a molten resin supply device that supplies molten resin to the inside of a metal cylinder attached to a metal cylinder.

[0002]

2. Description of the Related Art In general, a magnetic tape used for an audio tape recorder or a video tape recorder is mounted on a deck or a cassette via a tape guide. Then, the magnetic tape thus mounted is moved at a desired speed by the power of the drive source, and the operations of winding and rewinding are performed.
Guided by a non-rotating tape guide.

[0003] Therefore, it is said that the smoothness of the magnetic tape contact surface of the tape guide has an extremely great effect on maintaining the quality of the magnetic tape used repeatedly. And
Currently used tape guides of this type can be broadly classified into those made of synthetic resin and those made of metal. For the former synthetic resin, the smoothness is impaired because the roll surface of the tape guide becomes uneven and rough due to the generation of resin gas due to shear heat generated at the gate, but the outer periphery is cut and polished with a metal cylinder. Is generally used because a good smooth surface can be obtained.

[0004]

Conventionally, however, a tape guide using a metallic cylinder of this type has been used in which a resin molded into a cylindrical shape is press-fitted into this bearing portion.
After the press-fitting, a hole must be formed in order to obtain concentricity of the bearing hole with respect to the metal outer peripheral surface, which has a disadvantage that the mass production effect is reduced and the cost is increased.

In order to overcome such a problem, the inventor of the present invention inserts a synthetic resin into a metal cylindrical material formed to a predetermined size in advance, performs insert molding, and integrally forms a bearing with the cylindrical material. It has been found that by doing so, it is possible to obtain high precision and mass productivity. However, in the case of such insert molding, when the supply of the molding material into the mold of the injection molding machine is automatically or manually supplied, since the mutual molds are opened and closed each time, the molding cycle time is increased. In the case of using a vertical injection molding machine, for example, a plurality of prepared dies are placed on a rotary table and indexed by rotation to form another die during molding. There is also a method in which a metal cylinder is attached to the mold so as not to affect the molding cycle time. However, in this case, there is a problem that the apparatus is enlarged and the cost is increased.

Accordingly, an object of the present invention is to provide an inner wall of a metal cylinder mounted in a hollow portion of a second mold in a state where the first mold and the second mold are in contact with each other. In order to introduce a molten resin into a molding hollow formed by a shaft member inserted therein, a resin introduction hole is penetrated through a first mold and a second mold is coaxial with the introduction hole. Forming a shaft hole in
A hollow portion is formed in the second mold coaxially with the guide hole of the first mold so that the metal cylinder supplied to the guide hole is mounted by a moving body, and a second portion centered on the hollow portion is formed. An arc groove is formed in the mold contact surface, and this is communicated with the shaft hole, a plurality of radial grooves are formed from the arc groove toward the hollow portion axis, and the first mold is guided. A gate formed of a shallow groove was formed on the land provided on the end face of the hole so as to be in contact with the groove in the radial direction, and a radial gate corresponding to the gate was formed on the end face of the moving body, and was mounted in the hollow portion. A configuration in which the molten resin is introduced into the molding hollow portion through the arc groove and the gate into the molding hollow portion in the metal cylinder body, so that the injection molding machine can be mounted in the hollow portion of the second mold in a closed state. Molten resin in the hollow part for molding formed in the metal cylinder With improved quality by filling to be molded, to provide a feeder of molten resin by reducing the molding cycle time to improve the mass production effect can be achieved cost reduction.

[0007]

In order to achieve the above object, one of a first mold and a second mold of an injection molding machine is fixed, and the other is moved to contact each other. In a supply device for supplying a molten resin into a metal cylinder mounted in a hollow portion formed in a contact surface, the first mold and the second mold are brought into contact with each other in a state where the first mold and the second mold are in contact with each other. A hollow portion is formed on the surface, and the metal cylinder supplied to the guide hole inside the first mold is moved in the axial direction of the moving body so as to be coaxial with the second metal mold. When installed in the hollow part of the mold,
A hollow portion for molding is formed by the inner wall of the metal cylinder and a shaft member inserted therein from the opposite side to the moving body, and a guide hole of the first mold is formed so as to communicate with the hollow portion for molding. A resin introduction hole penetrating therethrough is formed in the vicinity, and a shaft hole for slidably inserting and supporting the locking shaft coaxially with the resin introduction hole is formed in the second mold and communicates with the shaft hole. An arc groove having a hollow center formed on the same axis as the first mold is formed on the contact surface of the lever mold, and a plurality of radii are formed from the arc groove toward the hollow part axis. And a gate formed of a shallow groove in contact with the radial groove is formed on a land provided at a contact portion of the guide hole end face of the first mold, and the movable body end face is formed on the land. Forming a radial gate corresponding to the gate, forming a hollow portion in a metal cylinder mounted in the hollow portion; Characterized by configured to introduce the molten resin through the gate.

[0008]

According to the molten resin supply apparatus of the present invention, the metal cylinder mounted in the hollow portion of the second mold in a state where the first mold and the second mold are in contact with each other. In order to introduce a molten resin into a molding hollow portion formed by an inner wall of the body and a shaft member inserted therein, a resin introduction hole is penetrated through a first mold and the second mold is provided with a resin introduction hole. A shaft hole is formed coaxially with the introduction hole, and a hollow portion is formed in the second mold coaxially with the guide hole of the first mold so that the metal cylinder supplied to the guide hole is mounted by the moving body. An arc groove is formed in the second mold contact surface centered on the hollow portion, and this is communicated with the shaft hole. A plurality of radial grooves are formed from the arc groove toward the hollow portion axis. And a gate formed of a shallow groove is formed on a land provided on the end face of the guide hole of the first mold so as to be in contact with the radial groove. And forming a radial gate corresponding to the gate on the end surface of the moving body, and introducing the molten resin into the molding hollow portion in the metal cylinder mounted in the hollow portion through the arc groove and the gate. By doing so, when the mold of the injection molding machine is closed, the molten resin is surely filled into the molding hollow portion formed in the metal cylinder mounted in the hollow portion of the second mold to perform resin molding. As a result, the quality can be improved, and at the same time, the molding cycle time can be shortened, the mass production effect can be improved, and the cost can be reduced.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an apparatus for supplying a molding material according to an embodiment of the present invention. FIGS. 1 to 4 show an embodiment of the present invention, and FIG. 1 is a plan sectional view showing a state in which a pair of molds are in contact with each other.

In the drawings, reference numeral 10 denotes a first mold. The first mold 10 is separated from each other by a compression spring 16 with respect to a base 17 mounted on an injection molding machine. A mold block 15 urged and supported movably within a predetermined range. In the figure, a broken line 14 indicates an abutting surface of the dies, and the movable die 12 as the second die is different from the fixed die 10 as the first die.
A hollow portion is formed on the mutual contact surface when the contact is made. Further, as shown in FIG. 1, an injection hole 22 that penetrates the mold block 15 is provided substantially in the center of the fixed die 10 to supply a synthetic resin. The guide hole 23 is the contact surface 14a of the mold block 15.
It is formed so as to open toward.

As shown in FIGS. 2 and 4 (a), when the dies are in contact with each other, a metal cylinder supplied from a supply cassette 24 fixed above the guide hole 23 is provided in the guide hole 23. A molding material 27 as a body is supported. On the same axis as the guide hole 23, an extrusion shaft 25, which is a moving body having one end fixed to the base 17, is provided immediately behind the metal cylinder 27.

Further, when the movable mold 12 abuts on the contact side end face of the guide hole 23, this is used as a land 21.
The land 21 has a gate 31 formed of a shallow groove radially arranged toward the center of the guide hole 23.
reference). A fitting hole 29 is provided at the center of the tip of the pushing shaft 25.
A metal cylinder is fixed in the fitting hole 29 with the fixing mold 1.
When the push-out shaft 25 is mounted in the through guide hole 37 as a hollow portion of the movable mold 12 by the axial movement of the pushing shaft 25, the stepped small-diameter portion 39 at the tip of the shaft member 40 provided in the movable mold 12.
Is inserted. Further, a gate (not shown) formed of a radial shallow groove is formed on the push-out shaft 25 toward a fitting hole 29 formed on the end face, and this gate is matched with the gate 31 formed on the land 21. As described above.

On the other hand, as shown in FIG. 1, the movable mold 12 comprises a mold block 26, a pair of intermediate blocks 28, and a base 30 on which the intermediate blocks 28 are mounted on the moving side of the injection molding machine. Further, a hollow chamber 32 is formed at the center of the intermediate block 28, and a pair of moving plates 34 combined with each other in the chamber 32 by the action of a compression spring 36.
It is pressed and supported on the 0 side.

Then, as shown in FIG.
6, a through-guide hole 37 having the same diameter as the guide hole 23 of the fixed mold 10 is formed coaxially with the guide hole 23. A hollow sleeve 38 is inserted into the guide hole 37 so as to be slidable in the axial direction. The head of the hollow sleeve 38 is clamped and fixed to the moving plate 34. Further, inside the hollow sleeve 38, a shaft member 40 having a stepped small diameter portion 39 formed at one end and a head formed at the other end and fixed to the base 30 is inserted therethrough (see FIG. 1). (See FIG. 1).

Further, as shown in FIG. 2 and FIG. 4 (b), when the dies are in contact with the contact surfaces 14b of the movable dies 12, they communicate with the resin injection holes 22 of the fixed dies 10. An arc-shaped groove 42 centered on the guide hole 37 serving as the runner 90 is formed on the contact surface, and the groove 42 is further configured to communicate with the gate 31 formed on the land 21 of the fixed mold 10. ing. Further, in a state where the molds are in contact with each other, a through-hole 44 is formed in the mold block 26 of the movable mold 12 coaxially with the injection hole 22 of the fixed mold 10,
In the through hole 44, a locking shaft 48 having a locking portion 46 at the tip is provided with a head formed at the rear end thereof.
4 and is slidably supported in the axial direction (FIG. 1).
reference).

Similarly, the runner 9 formed on the contact surface 14b of the mold 12 is provided on the mold block 26 of the movable mold 12.
At least two (one in the figure) through-holes 50 are drilled corresponding to the arc-shaped grooves 42 that become zero, and a push rod 52 is clamped with the head thereof to the moving plate 34 in this hole 50. It is slidably inserted.

Next, in the state where the pair of dies configured as described above are in contact with each other, the inner wall of the metal cylinder mounted in the hollow portion of the movable die and the small-diameter stepped portion at the tip of the shaft member are formed. The step of injecting the molten resin to be injected into the molding hollow portion will be described below.

That is, as shown in FIG.
In a state where the movable mold 12 is in contact with the contact surface 14a of the injection head 54, the injection hole 2 is measured by the nozzle of the injection head 54.
The molten resin injected from the mold 2 is transferred to the arc groove 42 of the moving mold 12.
And then communicates with the gate 31 formed on the land 21 on the fixed mold 10 contact surface from three protruding portions radially protruding toward the guide hole 37 inside the arc groove 42. After passing through a gate (not shown) at the tip of the extruding shaft 25, it is filled into a molding hollow portion formed by the small-diameter stepped portion 39 at the tip of the shaft member 40 and the inner wall of the metal cylinder 27.

The synthetic resin thus filled in the molding hollow portion in the metal cylinder is integrally formed as a tape guide bearing. In this case, as shown in FIG. 5, the solidified resin filled in the resin introduction hole from the injection hole 22 to the gate 31 and in the locking portion 46 at the tip of the locking shaft 48 is pulled by the locking shaft 46 to form a tapered shape. The spool 58 is separated from the small diameter portion.

Subsequently, as shown in FIG. 5, the movable mold 12 is moved backward to open the mold, and at the same time, the eject bar 56 is inserted through the through hole 54 of the base 30 to push the movable plate 34 against the compression spring 36. And press. When the eject bar 56 is pressed, the movable plate 34 relatively advances, and the hollow sleeve 38, the locking shaft 48, and the push rod 52 protrude from the contact surface 14b of the movable mold 12, respectively. In this case, the molding resin separated from the small-diameter portion of the spool 58 passes through the tapered spool 58 and a plurality of gates 31 arranged at equal angles toward the guide hole from the arc-shaped runner 90 communicating therewith. Thus, it is integrally molded with the resin filled in the molding hollow portion formed between the inner wall of the metal cylinder 27 and the stepped small diameter portion 39.

Accordingly, the molding resin separated from the nozzle of the injection head 54 and integrally formed with the spool 58, the runner 90 and the gate 31 is moved by the projecting operation of the hollow sleeve 38, the locking shaft 48 and the push rod 52. Is taken out from the front of

In this case, the movable plate 34 is pushed back against the spring 36 by the abutting action of the eject bar 56, and the four guide bars 60 fixed at the head to the base.
And can be translated.

Therefore, when the movable mold 12 is moved forward again to close the mold after the molding resin is taken out, the movable mold 12 is accurately positioned by the guide of the guide bar 62 having one end fixed to the base 17 of the fixed mold. After the mutual contact of the molds, the mold is clamped. That is, at the time of contact of the mold, the metal cylinder 27 supplied to the hollow portion of the fixed mold 10 is
When the fixed die 10 is pushed back against the urging force of the compression spring 16 by the contact with the movable die 12, the movable die 12 is moved by the relative movement of the extrusion shaft 25 fixed to the base 17. Is formed into a hollow portion for filling resin with the stepped small-diameter portion at the tip of the shaft member 40 and the inner wall of the metal cylindrical body 27. Thus, the metal cylinder 27
Can be reliably filled with a synthetic resin, and resin molding can be performed in a shorter time.

[0024]

As is apparent from the above-described embodiment, according to the present invention, the first mold and the second mold are placed in the hollow portion of the second mold in a state where they are in contact with each other. In order to introduce a molten resin into a molding hollow portion formed by an inner wall of a mounted metal cylindrical body and a shaft member inserted therein, a resin introduction hole is formed in a first mold and a second resin injection hole is formed. A shaft hole is formed coaxially with the introduction hole in the mold, and a metal cylinder body supplied to the guide hole is coaxially mounted with the guide hole of the first mold in the second mold by a moving body. A hollow portion is formed, and an arc groove is formed in a second mold contact surface centered on the hollow portion, and this is communicated with the shaft hole. Are formed in a radial groove, and a land provided on an end face of the guide hole of the first mold is formed from a shallow groove so as to be in contact with the radial groove. Forming a radial gate corresponding to the gate on the end surface of the moving body, and supplying molten resin to the molding hollow portion inside the metal cylinder mounted in the hollow portion through the arc groove and the gate. By adopting the configuration, the molten resin is reliably filled in the molding hollow portion formed in the metal cylinder mounted in the hollow portion of the second mold in a state where the mold of the injection molding machine is closed. It is possible to improve the quality by performing resin molding by using the resin, and at the same time, it has excellent effects such as shortening the molding cycle time, improving the mass production effect, and achieving a reduction in cost. Although the preferred embodiment of the present invention has been described, it is needless to say that the present invention is not limited to the above-described embodiment, and that various design changes can be made without departing from the spirit of the present invention.

[Brief description of the drawings]

FIG. 1 is a cross-sectional plan view illustrating an embodiment of the present invention, in which a metal cylinder is mounted in a hollow portion of a movable mold by an extrusion shaft in a state where a pair of molds are in contact with each other. .

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an enlarged sectional view of a main part of FIG.

FIG. 4 is a perspective view showing one embodiment according to the present invention and showing a gate and a runner respectively formed on contact surfaces of a pair of molds.

FIG. 5 is a plan sectional view showing a state where a pair of molds are separated from each other and opened.

[Explanation of symbols]

10 (first mold) Fixed mold 12 (second mold)
Mold) Moving mold 15, 26 Mold block 16, 36
Compression spring 17, 30 Base 21 Land 22 Injection hole 23, 37
Guide hole 24 Supply cassette 25 Push-out shaft 27 Metal cylinder 28 Intermediate block 29 Fitting hole 31 Gate 32 Hollow room 34 Moving plate 38 Hollow sleeve 39 Stepped small diameter portion 40 Shaft member 42 Arc groove 46 Locking portion 48 Locking shaft 56 Eject bar 58 Spool 90 Runner

Claims (1)

(57) [Claims] 1. An injection molding machine wherein one of a first mold and a second mold is fixed, and the other is moved and abuts with each other to be mounted in a hollow portion formed in the contact surface. In a supply device for supplying a molten resin into a metal cylinder, a first mold and a second mold are provided.
A hollow portion is formed in the contact surface in a state where the metal mold is brought into contact with the mold, and the metal cylinder supplied to the guide hole inside the first mold is moved in the axial direction of the moving body. When mounted in the hollow portion of the second mold formed coaxially with the movement of the metal cylinder, the molding hollow is formed by the inner wall of the metal cylinder and the shaft member inserted into the inside of the metal cylinder from the side opposite to the moving body. Form a part,
A resin introduction hole penetrating therethrough is formed near the guide hole of the first mold so as to communicate with the hollow portion for molding, and a locking shaft is coaxially formed with the resin introduction hole in the second mold. A shaft hole for slidably inserting and supporting the shaft hole, and communicating with the shaft hole, an arc groove centered on a hollow portion formed on the same axis as the first mold on a contact surface of the mold. Forming a plurality of radial grooves from the arc groove toward the hollow portion axis,
Further, a gate formed of a shallow groove that is in contact with the radial groove is formed on a land provided at the contact portion of the guide hole end face of the first mold, and a radial gate that matches the gate is formed on the moving body end face. A molten resin supply device, wherein the molten resin is introduced into the molding hollow portion in the metal cylinder mounted in the hollow portion through the gate.