JPH0317656B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method for manufacturing shaft end plug members for rollers, etc. used in automatic photo film processors, electrophotographic copying machines, office equipment, etc. be.

[Conventional technology]

An automatic developing machine for photographic film automatically develops photographic film, and has a developing section, a fixing section, a washing section, and a drying section, and the photographic film is developed through each of the above sections. That is, among the above-mentioned sections, the developing section is provided with a developing solution (alkaline) bath tank, and the fixing section is provided with a fixing solution (acidic) bath tank. Continuously transport, develop,
It is becoming established.

As shown in FIG. 8, the rollers used in each liquid bath tank of the automatic developing machine for photographic film have stainless steel rotary shafts 7 in the left and right openings of the cylindrical synthetic resin roller body 6. There is one constructed by inserting an end cap 8 made of synthetic resin. The shaft end plug member (end cap) 8 of such a roller is inserted into the rotating shaft 7 in the molding space (cavity) 10 of the injection mold 9, as shown in FIG.
One end side of the shaft material 7a is inserted, and in that state, synthetic resin for injection molding (thermoplastic resin, thermosetting resin) is injected into the cavity 10 through the spool 12 from the injection molding nozzle 11 and hardened. , and then the mold 9 is opened. In FIG. 9, reference numeral 13 denotes a protruding pin, which prevents the shaft member 7a from moving to the left in the figure due to the injection pressure of the synthetic resin.

[Problems to be Solved by the Invention] However, since the rotating shaft of the end cap is made of stainless steel, it lacks chemical resistance compared to one made of synthetic resin, and an improvement is desired.

Therefore, recently, in place of the above-mentioned end cap, an end cap whose entire body including the rotating shaft is made of synthetic resin has been developed and has been put into practical use in some cases. However, since the rotating shaft itself of such an end cap is made of synthetic resin, the rotating shaft may bend and the straightness of the rotating shaft 14 may deteriorate, as shown in FIG. 11. As shown, the rotating shaft 14 becomes tapered or the first
As shown in FIG. 2, there is a problem that the rotary shaft 14 has a poor circularity due to the elliptical shape. Therefore, it is desired to improve such synthetic resin end caps.

The present invention was made in view of the above circumstances, and an object thereof is to provide a method for easily manufacturing a shaft end plug member for a roller that is highly chemical resistant and has excellent straightness and roundness. do.

[Means for solving problems]

In order to achieve the above object, the method for manufacturing a roller shaft end plug member of the present invention includes a cylindrical plug part for plugging an opening of a cylindrical roller, and a cylindrical plug part that protrudes from the center of the end surface of one end of the cylindrical plug part. A roller shaft end plug member is made of synthetic resin by injection molding into a roller shaft end plug member, which is equipped with a rotating shaft portion and a rod-shaped reinforcing material coaxially embedded in both the cylindrical plug portion and the rotating shaft portion while straddling both parts. A method of manufacturing by molding, in which a mold is formed in at least two places on one end side evenly in the outer circumferential direction in a mold forming space consisting of a space for forming a cylindrical plug part and a space for forming a rotating shaft part communicating with this space. A rod-shaped reinforcing material provided with a protruding protrusion is inserted with the one end thereof positioned in the space for forming the rotating shaft part in the molding space, and the space for forming the cylindrical plug part and the space for forming the rotating shaft part are connected. The synthetic resin is injected from the part of the mold facing the communication part in the direction of the space for forming the rotating shaft part.

That is, in this invention, as a rod-shaped reinforcing material,
A rod-shaped reinforcing material is used in which protrusions protruding toward the outer periphery are formed at at least two locations on one end side, and the protrusions are positioned within the rotating shaft forming space in the molding space of the injection mold. In order to perform injection molding by entering the reinforcing material into the molding space, when the injected resin enters the rotating shaft forming space under a predetermined pressure, it passes through the outer circumferential surface of the protrusion of the reinforcing material.
In this case, the distance between the outer periphery of the protrusion and the wall surface of the rotating shaft forming space is sharply smaller than other parts, and is uniform along the outer periphery of the protrusion.
The pressure of the resin passing through this narrow portion increases rapidly, and the pressure becomes equal around the outer periphery of the protrusion. As a result, the rod-shaped reinforcing material is floated by the above pressure, and is automatically positioned on the central axis of the space for forming the rotating shaft part by the balance of the pressure. Therefore, the roller shaft end plug member in which the reinforcing material is coaxially embedded can be manufactured in one step of injection molding, without providing any special positioning means or process.

Next, embodiments of the present invention will be explained.

〔Example〕

FIG. 1 shows an example of an injection mold used in the present invention. The mold 9 is made up of two halves and has a molding space (cavity) 10 inside. 15 is a space for forming a cylindrical plug portion of the cavity 10, and 16 is a space for forming a rotating shaft portion communicating therewith. The spool 12
extends to the nozzle touch portion 11a. 13 is a protruding pin, and from the end surface of the tip, pin 13
a extends into the rotating shaft forming space 16.
FIG. 2 shows an example of a rod-shaped reinforcing material used in the present invention. This reinforcing member 17 consists of an iron rod 17a and a washer-like resin ring 18 fitted around the outer periphery of the iron rod 17a.
It is used by being fitted externally at one end of the holder at predetermined intervals and formed into a protrusion.

The roller shaft end plug member of the present invention is manufactured using the above-mentioned apparatus in the following manner. That is, as shown in FIG. 3, the rod-shaped reinforcing member 17 on which the resin ring 18 is fitted is placed into the cavity 10. At this time, two resin rings 18 are placed in the rotating shaft forming space 16 in the cavity 10.
Position it so that it fits. In this state, the injection molding nozzle 11 is positioned on the nozzle touch portion 11a and ABS resin is injected. Due to the pressure during this injection, the injected resin flows into the cavity 1.
It enters into the rotating shaft part forming space 16 at 0 with force. At this time, the injected resin is added to the rod-shaped reinforcing material 1
It passes through the gap between the outer periphery of the resin ring 18 fitted on the outside of the ring 7 and the wall surface of the space 16, and reaches the inner part of the rotating shaft forming space 16 while applying uniform pressure to the entire outer periphery of the ring 18. Due to the above pressure, the rod-shaped reinforcing member 17 floats to the center of the rotating shaft portion forming space 16 and is positioned coaxially. That is,
The injected resin is applied to the rod-shaped reinforcing material 17 as described above.
In order to apply uniform pressure over the entire outer periphery of the resin ring 18, the rod-shaped reinforcing material 17 floats due to the pressure and is automatically positioned on the central axis of the rotating shaft forming space 16. After the injected resin is cooled and hardened, the mold is opened, the molded product is taken out, and the resin is filled into the hole where the pin 13a of the protruding pin 13 was removed, resulting in a product as shown in FIG.
A shaft end plug member 22 is obtained in which the rod-shaped reinforcing member 17 is coaxially embedded in both the rotating shaft portion 20 and the cylindrical plug portion 21 with the rod-shaped reinforcing member 17 spanning both parts. As shown in FIG.
It is attached by fitting the

In the shaft end plug member 22 of the roller, a highly rigid reinforcing material 17 is coaxially provided on the shaft portion, so that the straightness and roundness of the rotating shaft portion 20 are improved by the action of the reinforcing material 17. Retained.

In addition, when forming the shaft end plug member 22 as described above, the injection pressure of resin such as ABS resin has a large influence on the floating of the rod-shaped reinforcing member 17. Then, the resin ring 1 in the rod-shaped reinforcing material 17 is
8 is preferably formed of the same resin as the plug member 22, and such a resin ring 1
In order to levitate the rod-shaped reinforcing material 17 equipped with
It is preferable to set it to 150Kg/cm ² . As a result, the rod-shaped reinforcing material 17 can be very precisely
It comes to be positioned coaxially with the rotating shaft portion 20 of the plug member 22.

In addition, in the above embodiment, as the rod-shaped reinforcing material formed in the protrusion part which protrudes in the outer circumferential direction at least at two places on one end side, a material in which two ABS resin rings 18 are fitted around the iron rod 17a is used. However, as shown in FIGS. 6a and 6b, a reinforcing material may be used in which four protrusions are evenly protruded in the circumferential direction at predetermined locations on a metal rod-shaped body. Also, Figure 7a,
As shown in FIG. 6B, a pipe with one end closed and a protrusion similar to that shown in FIG. 6 may be used, and in these cases, the same effect as described above can be achieved. Furthermore, it goes without saying that the ring 18 may have two or more protrusions. Further, in the above embodiment, the pin 13a is made to protrude from the protruding pin 13, and the pin 13a is
Although positioning is performed by bringing the end face of the rod-shaped reinforcing member 17 into contact with a, the protruding pin 13 does not necessarily need to be provided. That is, the injected resin reaches the depths of the rotating shaft forming space 16 in the cavity 10 and is then reversed from there, so that the rod-shaped reinforcing material 17 is automatically positioned by the reverse pressure. It is.

〔Effect of the invention〕

As described above, according to the method for manufacturing a roller shaft end plug member of the present invention, a rod-shaped reinforcing material having at least two protrusions projecting in the outer circumferential direction on one end side is formed into the above-described molding method. The mold is placed into the molding space of the mold in a state in which it is positioned within the space for forming the rotating shaft part in the space, and from the part of the mold facing the entrance of the space for forming the rotating shaft part, it is synthesized in the direction of the space for forming the rotating shaft part. In order to inject the resin, the rod-shaped reinforcing material automatically floats with its own central axis aligned with the central axis of the space for forming the rotating shaft portion. Therefore, a shaft end plug member for a roller in which a rod-shaped reinforcing material is embedded coaxially can be manufactured extremely easily without providing special positioning means or processes.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of an injection mold used in the present invention, Fig. 2 is an exploded perspective view of an example of a rod-shaped reinforcing material also used in the present invention, and Fig. 3 is a plug member manufactured using the reinforcing material. 4 is a longitudinal sectional view of a plug member obtained thereby, FIG. 5 is a longitudinal sectional view of a roller obtained using the plug member of FIG. 4, and FIGS. 6 and 7. is another example of rod-shaped reinforcement,
In each case, a shows a perspective view and b shows a side view. FIG. 8 is a longitudinal sectional view of a conventional example, FIG. 9 is an explanatory diagram of manufacturing a plug member in the roller, and FIGS. 10, 11, and 12 are explanatory diagrams of a conventional synthetic resin end cap. 9... Mold, 10... Molding space, 11... Nozzle, 15... Space for forming a cylindrical plug part, 16... Space for forming a rotating shaft part, 16a... Communication part, 17...
Rod-shaped reinforcing material, 17a... Iron rod, 18... Resin ring, 20... Rotating shaft portion, 21... Cylindrical plug portion, 2
2...Roller shaft end plug member.

Claims (1)

[Claims] 1. A cylindrical plug part for plugging the opening of the cylindrical roller, a rotating shaft part protruding from the center of the end surface of one end of the cylindrical plug part, and a rotary shaft part on both the cylindrical plug part and the rotating shaft part. A method of manufacturing a shaft end plug member of a roller equipped with a rod-shaped reinforcing material coaxially buried in both parts in a loose state by injection molding of synthetic resin, the method includes a space for forming a cylindrical plug part and a space for forming a cylindrical plug part. A rod-shaped reinforcing member provided with protrusions that protrude evenly in the outer circumferential direction at at least two places on one end side is placed in a mold molding space consisting of a space for forming a rotary shaft part communicating with the molding space. The mold is positioned in the rotating shaft forming space, and is inserted in the direction of the rotating shaft forming space from the part of the mold that faces the communication portion between the cylindrical plug forming space and the rotating shaft forming space. A method for manufacturing a roller shaft end plug member, characterized by injecting synthetic resin.