JPH058247A - Resing formed body of metallic tubular body - Google Patents

Abstract

PURPOSE:To obtain highly accurate resin formed body having improved mass production effect by a method wherein resin is poured in the inner wall of a metallic tubular body used for a tape guide or the like so as to integrally form resinous bearing part with the metallic tubular body. CONSTITUTION:Through the forming of resin by pouring molten resin in the inner wall of a metallic tubular body 27, the resin formed part in the metallic tubular body 27 is formed integrally with a sprue 58, a runner 90 and a gate 31. The resin formed part in the metallic tubular body 27 is formed to be cut off the main resin formed body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal cylinder body in which a molding hollow portion is formed in a metal cylinder body, and a molten resin is injected into the molding hollow portion to mold the resin on the inner wall of the metal cylinder body. The present invention relates to a resin molded body.

[0002]

2. Description of the Related Art A magnetic tape generally used in an audio tape recorder or a video tape recorder is mounted on a deck or a cassette via a tape guide when the magnetic tape is used. Then, the magnetic tape mounted in this way moves at a desired speed by the power of the drive source, and the winding and rewinding operations are performed.
Guided by a non-rotating tape guide.

Therefore, it is said that the smoothness of the magnetic tape contact surface of the tape guide has an extremely large influence on the quality maintenance of the magnetic tape used repeatedly. And
Currently used tape guides of this kind can be roughly classified into those made of synthetic resin and those made of metal. With the former synthetic resin, smoothness is impaired because the roll surface of the tape guide becomes uneven due to the generation of resin gas due to shearing heat generation at the gate part, but the latter is cut and polished on the outer circumference with a metal cylinder. Since the surface treatment is performed and a good smooth surface is generally obtained, it is generally used.

[0004]

However, in the past, a tape guide using a metal cylinder of this type has heretofore been used in which a resin molded in a cylindrical shape is press-fitted into this bearing portion.
After press-fitting, hole processing had to be performed in order to obtain concentricity of the bearing hole with respect to the metal outer peripheral surface, which had the drawback of reducing the mass production effect and increasing the cost.

Therefore, an object of the present invention is to inject a molten resin into a metal cylinder body to form a resin molding portion on the inner wall of the metal cylinder body so that the metal cylinder body and the injection path form an outer shell of the resin molding body. It is an object of the present invention to provide a resin molded body of a metal cylindrical body which can improve the quality of the resin molded body, improve the mass production effect, and achieve cost reduction by molding.

[0006]

The present invention is characterized in that, in a resin molded body formed by molding, a metal cylinder forms an outer shell of the resin molded body.

In this case, when the metal cylinder is mounted in the hollow part of the mold, resin is injected into the molding hollow part formed inside the metal cylinder to mold the resin on the inner wall of the metal cylinder. It is preferable to have such a configuration.

Further, the resin molding portion of the inner wall of the metal cylinder body constitutes a part of the resin molding body, and the end portion of the resin molding portion of the inner wall of the metal cylinder body is separable by the action of tensile force. You can also do it.

Further, the resin molding portion on the inner wall of the metal cylinder forms a part of the resin molding, and the connecting portion between the resin molding portion on the inner wall of the metal cylinder and the resin molding body is the resin molding. It may be configured to be cuttable with respect to the body.

The resin molding portion of the inner wall of the metal cylinder forms a part of the resin molding body, and the resin molding portion of the inner wall of the metal cylinder and the resin molding body are singular or plural. It is also possible to configure the connection by a resin molding portion that is thinner than the resin molding portion.

[0011]

According to the resin molded body of the metal cylinder according to the present invention,
Molten resin is injected into the molding hollow formed in the metal cylinder to form a resin molding portion on the inner wall of the metal cylinder, and the metal cylinder is integrally formed with the injection path so as to be the outer shell of the resin molding. In addition, it is possible to improve the quality of the resin molded body, improve the mass production effect, and achieve cost reduction. Preferably, the resin molded portion of the metal cylinder is formed so as to be cut from the resin molded body so that the resin molded body can be cut.

[0012]

EXAMPLE An example of a resin molded body of a metal cylinder according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of the present invention and is a plan sectional view showing a state where a pair of molds are in contact with each other. In the figure,
Reference numeral 10 indicates a first mold, and the first mold 10
Is a base 17 attached to the injection molding machine and this base 1
7, a compression block 16 normally biases and supports them in a mutually separated state, and a mold block 15 is provided so as to be movable within a predetermined range. In this case, the fixed die 10 as the first die slides through the guide bushes 64 inserted into the die 10 by the four guide bars 62 whose one end is fixed to the base plate 17 on the fixed side. Guided and supported as possible. Furthermore, a guide bush 64 is inserted coaxially with the guide bar 62 in the movable mold 12 that is movably opposed to the fixed mold 10, and the movable mold 12 moves back and forth with respect to the fixed mold 10. On the other hand, it accurately supports this.

In FIG. 1, a broken line 14 indicates a contact surface between the molds, and when the movable mold 12 which is the second mold is contacted with the fixed mold 10, the contact surfaces are hollow. Parts are formed. Further, as shown in FIG. 1, an injection hole 22 penetrating the mold block 15 for injecting the synthetic resin is provided at substantially the center of the fixed mold 10, and a guide as a hollow portion is provided in parallel with the injection hole 22. The hole 23 is formed so as to open toward the contact surface 14 a of the mold block 15.

FIG. 2 shows the case where the molds are in contact with each other. In the initial state, the molds 10 and 1 are in mutual contact.
2 is in an open state as shown in FIG. 4, and in this state, in the guide hole 23 formed in the fixed mold 10, the supply cassette 2 vertically mounted above the guide hole 23 so as to communicate therewith.
The metal cylinder 27 supplied from No. 4 is supported. And
A metal cylinder 27 supported in the guide hole 23 as shown in the figure.
Immediately behind the shaft is an extrusion shaft 2 with one end fixed to the base 17.
5 are provided.

Further, as shown in FIG. 3A, the contact side end surface of the guide hole 23 is used as the land 21 when the movable die 12 contacts, and the land 21 has the guide hole 23. Gate 3 formed by radial shallow grooves toward the center
1 is provided. A fitting hole 29 is formed at the center of the tip of the pushing shaft 25 shown in FIG. 2, and a metal cylinder 27 is moved in the fitting hole 29 by moving the pushing shaft 25 of the fixed mold 10 in the axial direction. Penetration guide hole 3 as a hollow part of the mold 12
The shaft member 4 provided on the movable die 12 when mounted in the inside 7
The stepped small-diameter portion 39 at the 0 tip is inserted and fitted. At the same time, a molding hollow portion is formed between the inner wall of the metal cylinder 27 and the stepped small diameter portion 39 of the shaft member 40 which is inserted and supported in the inside.

In this case, the metal cylinder 2 shown in FIG.
At the end face of the pushing shaft 25 that presses 7 in the axial direction, a gate formed of a radial shallow groove is engraved toward a fitting hole 29 formed in the end face, and this gate is formed on the land 21 in the radial direction. The angle of the extrusion shaft 25 is determined so as to match the gate 31, and is fixed to the base 17.

On the other hand, as shown in FIG. 1, the movable mold 12 is composed of a mold block 26, a pair of intermediate blocks 28, and a base 30 on which the intermediate block 28 is mounted on the moving side of the injection molding machine. Further, a hollow chamber 32 is formed in the middle of the intermediate block 28, and a pair of moving plates 34 integrated with each other are provided in the chamber 32 by the action of the compression spring 36.
It is pressed and supported on the 0 side. A through guide hole 37 having the same diameter as the guide hole 23 of the fixed mold 10 is formed in the mold block 26 of the movable mold 12 coaxially with the guide hole 23. The hollow sleeve 38 has a head portion fixedly mounted on the moving plate 34 in a slidable manner (see FIG. 2). Further, as described above, the shaft member 40 having the stepped small diameter portion 39 formed at one end and the head portion formed at the other end and fixed to the base 30 is inserted into the hollow sleeve 38. It is arranged.

As shown in FIGS. 2 and 3 (b), the movable mold 12 is communicated with the resin injection hole 22 of the fixed mold 10 in a state where the molds are in contact with the contact surface 14b. Thus, an arc-shaped groove 42 centering on the guide hole 37 is formed, and this groove 42 is further configured to communicate with the gate 31 formed on the land 21 of the fixed mold 10. Further, when 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, and the tip of the through hole 44 is engaged with the through hole 44. A locking shaft 48 having a stopper 46 is attached to the moving plate 34 with a head formed at the rear end thereof being slidably supported in the axial direction (see FIG. 1).

Similarly, in the mold block 26 of the movable mold 12, at least two (one in the figure) through holes corresponding to the arc-shaped grooves 42 formed on the contact surface 14b of the mold 12 are formed. A hole 50 is formed in the hole 50. A push rod 52 is inserted into the hole 50 such that the head of the push rod 52 is attached to the moving plate 34 so as to be slidable in the axial direction.

Next, in a state where the pair of molds configured as described above are in contact with each other, the mold is injected into the molding hollow part of the metal cylinder mounted in the hollow part of the moving mold through the injection path. The molten resin injection step will be described below. That is, as shown in FIG. 2, in a state where the moving mold 12 is brought into contact with the contact surface 14 a of the fixed mold 10, the injection head 5
The molten resin measured from the nozzle No. 5 and injected from the injection hole 22 flows into the arc groove 42 of the moving die 12, and then three points radially project toward the guide hole 37 inside the arc groove 42. The small diameter stepped portion 39 at the tip of the shaft member 40 passes through the gate 31 formed on the land 21 on the contact surface of the fixed mold 10 and the gate (not shown) at the tip of the pushing shaft 25 communicating with this from the protruding portion of And a resin molding portion is formed by being injected into a molding hollow portion formed by the inner wall of the metal cylinder 27.

In this way, the locking shaft 48 slidably fitted in the injection hole 22 penetrating the mold block 15 of the fixed mold 10 and the through hole 44 of the movable mold 12 serving as the injection path. Locking part 46 at the tip, movable mold 1 to communicate with this
2 Circular arc groove 4 centered on the guide hole 37 formed on the contact surface
2. When the molten resin injected from the arc groove 42 through the gate 31 formed in the land 21 and the gate at the end of the extrusion shaft 25 into the molding hollow portion in the metal cylinder 27 solidifies, the inside of the metal cylinder The resin supplied to is integrally molded with the spool 58, the runner 90, and the gate 31 as a bearing of the tape guide as a resin molded body.

Subsequently, as shown in FIG. 4, when the movable die 12 further moves backward with the synthetic resin injected, the injection hole 2 is injected into the engaging portion 46 at the tip of the engaging shaft 48 and solidified.
The spool 58 extending from 2 to the gate 31 is pulled by the locking shaft 46 and separated from the small diameter portion of the tapered spool 58 which is the end portion of the resin molding portion.

The movable mold 12 is moved backward to open the molds 10 and 12 from each other, and at the same time, the eject bar 56 is inserted from the rear of the base 30 through the through hole 54 to abut the movable plate 34. By moving plate 3
4 is pressed against the compression spring 36. When the eject bar 56 is further pressed, the moving plate 34 advances relative to the moving mold 12, and the hollow sleeve 38, the locking shaft 48, and the push rod 52 respectively project forward from the contact surface 14b of the moving mold 12. To do. By these projecting operations, the resin molded body main body separated from the nozzle of the injection head 55 is taken out from the front of the moving mold 12.

However, as shown in FIGS. 5 to 6, the resin-molded portion of the metal cylinder molded together with the resin injected into the injection path is a resin-molded body main body integrally molded with the spool, runner, and gate. After being taken out to the inner wall of the metal cylindrical body 27, the metal cylindrical body 27 after molding is artificially twisted and cut off from the gate portion as a connecting portion between the resin molded portion and the resin molded body. The product filled with resin is completed.

A single or a plurality of metal cylinders are arranged around the resin injection hole 22 and a thin resin is formed on the resin molding portion of the inner wall of the metal cylinder 27 from the resin injection hole 22 as the resin molding body. By composing the gate 31 as a molding line so as to communicate with each other, the mass productivity of the resin molded body can be further improved. In this way
It is possible to reliably inject the synthetic resin into the inside of the metal cylinder 27 and perform the resin molding in a shorter time.

[0026]

As is apparent from the above-described embodiments, according to the present invention, the molten resin is injected into the metal cylinder body to form the resin molding portion on the inner wall of the metal cylinder body, and the metal cylinder body together with the injection path. By integrally forming the resin molded body so as to form the outer contour of the resin molded body, not only the quality of the resin molded body is improved, but also the mass production effect is improved and the cost can be reduced. Although the preferred embodiments of the present invention have been described, the present invention is not limited to the above embodiments, and it is needless to say that various design changes can be made without departing from the spirit of the present invention.

[Brief description of drawings]

FIG. 1 is a plan sectional view showing an embodiment according to the present invention and showing a state 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 an enlarged cross-sectional view of a main part of FIG.

FIG. 3 shows an embodiment according to the present invention, in which (a) is a perspective view showing a gate formed on a land of a first mold, and (b) is a second mold. It is a perspective view showing an arcuate groove formed on the contact surface of.

FIG. 4 is a plan sectional view showing a state in which a pair of molds are separated from each other and opened.

FIG. 5 is an overall perspective view of a resin molded body of a metal cylinder showing an embodiment according to the present invention.

FIG. 6 shows an embodiment according to the present invention, in which (a) is a plan view of a resin molded body of a metal cylinder, and (b) is (c).
FIG. 6B is a view as viewed from the arrow B in FIG.

[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 Extrusion shaft 27 Metal cylinder 28 Intermediate block 29 Fitting hole 31 Gate 32 Hollow chamber 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 (5)

[Claims] 1. A resin molded body formed by molding, wherein the metal cylinder forms an outer contour of the resin molded body. 2. When a metal cylinder is mounted in the hollow part of a mold, a resin is injected into a molding hollow part formed inside the metal cylinder so that the inner wall of the metal cylinder is resin-molded. The resin molded body of the metal cylinder according to claim 1, wherein 3. The resin molding portion of the inner wall of the metal cylinder forms a part of the resin molding body, and the end of the resin molding portion of the inner wall of the metal cylinder is separable by the action of tensile force. The resin molded body of the metal cylinder according to claim 1, wherein 4. The resin molding portion of the inner wall of the metal cylinder forms a part of the resin molding, and the connecting portion between the resin molding portion of the inner wall of the metal cylinder and the resin molding body is the resin molding. The resin molded body of the metal cylinder according to claim 1, wherein the resin molded body is configured to be cuttable with respect to the body body. 5. The resin molding portion of the inner wall of the metal cylinder forms a part of the resin molding body, and the resin molding portion of the inner wall of the metal cylinder and the resin molding body are singular or plural. The resin molded body of the metal cylinder according to claim 1, wherein the resin molded body is connected by a resin molded section thinner than the resin molded section.