JP2001219431A - Resin roller and its core as well as mold for molding resin roller and method for molding the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To omit or reduce man-hours for removing a runner by preventing residue of a part of the runner at a resin molding or a defecting the resin molding in the case of removing the runner generated in the case of pouring a resin in a mold in molding a resin roller. SOLUTION: The cylindrical resin molding is formed on a periphery of a core 21 by holding both ends at core holding members 14a, 14b in the mold having a cylindrical mold 13 and the members 14a, 14b mounted at both ends of the mold 13, mounting the core 21, charging the resin in a molding space 15 of the mold via a resin charging passage 20 provided at the core 1 and curing the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin roller such as a developing roller, a charging roller, a transfer roller and the like which are incorporated in various apparatuses employing an electrophotographic system such as a laser printer, a copying machine, a facsimile machine, and the like. And a molding die and a molding method for the resin roller.

[0002]

2. Description of the Related Art Various apparatuses employing an electrophotographic method, such as a laser printer, a copying machine, and a facsimile machine, incorporate resin rollers such as a developing roller, a charging roller, and a transfer roller. FIG. 12 shows an example of such a resin roller.
13 is a perspective view, and FIGS. 13A and 13B are cross-sectional views. The resin roller 10 has a core 21 and a cylindrical resin molded portion 12 formed of a synthetic resin around the core 21. A mold for molding such a resin roller 10 is, for example, a cylindrical mold 13 and attached to both ends of the cylindrical mold 13 like a molding mold 100 shown in FIG. The end shaft portions 211 at both ends of the core 21 inserted into the mold 13 are inserted and held in the core insertion holes 141, and both ends of the cylindrical mold 13 are sealed to form the roller molding space 15. It has a pair of core holding members 14a and 14b. The core holding member 14a on the resin injection side communicates with the molding end surface 151 of the roller molding space 15 in the cylindrical mold 13 from the outer end surface thereof to inject the resin material into the roller molding space 15. A resin injection path 16 is formed.
At the time of molding, a resin injection nozzle 18 of a molding machine is pressed against a nozzle touch portion 19 having a semicircular cross section formed outside the mold of the resin injection path 16, and the inside of the roller molding space 15 is formed through the resin injection path 16. Is filled with a resin material.
The core holding member 14a on the resin injection side may be provided with an air bleeding mechanism for bleeding air from the roller molding space 15 during resin injection. After the filling of the resin into the roller molding space 15 of the mold is completed as described above, the resin is heated and cured. After the curing of the resin is completed, the core holding members 14a and 14b are moved outward from the cylindrical mold 13 along the axial direction thereof (upward or downward when the longitudinal direction of the mold is set up vertically). Unplug. Next, the core body 21 is extruded into the cylindrical mold 13 or the like so that the cylindrical mold 13
Take out the molded product held inside.

However, when the resin in the roller molding space 15 is cured, the resin in the resin injection path 16 of the core body holding member 14a opened in the molding end surface 151 of the roller molding space 15 is also heated and cured at the same time. When the resin is taken out, the resin in the resin injection path 16 is formed integrally with the end face 121 of the resin molding portion 12 as a runner 17 as shown in FIG. The runner 17 is torn off in the axial direction in a later step, or cut and removed by a cutter, a nipper, scissors, or the like. However, when the cross-sectional area of the resin injection path 16 in the core holding member 14a is increased or the thickness of the resin molding portion 12 is small in order to shorten the time of resin injection into the mold during roller molding, In addition, the ratio of the cross-sectional area of the runner 17 to the end surface 121 of the resin molded portion increases, and the work of removing the runner 17 becomes difficult. For this reason, as shown in FIG. 15B, when the runner 17 is removed, a part 17a of the runner 17 protrudes from the end surface 121 of the resin molded portion or remains, or as shown in FIG.
As shown in (2), when the runner 17 was removed, the edge 122 of the resin molded portion 12 was lost. In addition, it takes a lot of man-hours to precisely remove the runner in order to eliminate the above-described defective runner removal.

[0004]

As described above, conventionally, when a resin roller is formed, a roller forming space 15 of a die constituted by a cylindrical die 13 and a pair of core holding members 14 is used. The resin injection path 16 for injecting resin into the
Since the opening in the molding end surface 151 in the roller molding space 15, the resin in the resin injection path 16 is hardened, and the runner 17 is integrally formed with the end surface 121 of the resin molding portion 12 in the molded product, and the runner 17 is removed. At this time, a runner removal failure occurs in which a part 17a of the runner 17 protrudes and remains on the resin molding portion end surface 121 or the resin molding portion edge 122 is lost. In order to reduce such runner removal failure. Also took time to remove the runners.

The present invention has been made in view of the above situation, and an object of the present invention is to remove a runner generated when a resin is injected into a mold in the molding of a resin roller, and to apply a runner to a resin molding portion. To prevent a part of the resin from remaining or causing the resin molded part to be damaged, and to eliminate or reduce the number of steps related to runner removal.

[0006]

In order to achieve the above object, a resin roller according to the present invention comprises a molding method in which a resin is injected into a mold using a molding die having a core body preliminarily mounted therein and cured. Accordingly, in a resin roller having a cylindrical resin molded portion formed around a core, a resin injection path is provided from an end shaft portion of the core to a resin molded portion.

In the resin roller according to the present invention as described above, a resin is injected into a mold using a molding die in which a core is inserted in advance, and the resin is cured to form a cylindrical shape around the core. When forming the resin molded part, the resin injection path for injecting the resin material into the molding space of the mold is open to the resin molded part of the core, and the resin material for forming the resin molded part is: The resin material was injected into the roller molding space from the peripheral side surface of the core of the resin molded portion through the resin injection path provided in the core from the end shaft portion of the core, so that the mold was filled with the resin material and heated and cured. Thereafter, the runner in which the resin in the resin injection path is hardened is not integrally formed on the outer surface of the resin molded portion. Therefore,
A runner in which a part of the runner protrudes and remains on the outer surface such as the molding end surface of the resin molding portion when the runner is removed as in the related art, or a part of the resin molding portion such as the edge of the resin molding portion is lost. There is no risk of defective removal. Therefore, man-hours related to runner removal for reducing runner removal failure can be omitted or reduced.

In one embodiment of the present invention, a hollow resin injection hole is provided as an opening in the end face of the core body and the peripheral side surface of the resin molded portion as the resin injection path. Inject resin into the mold. Further, in another embodiment, as the resin injection path,
A resin injection groove is provided on the peripheral side surface from the shaft end of the core body to the resin molding portion, and the resin is injected from the resin injection nozzle into the mold through the resin injection groove. Further, in this case, the D-cut portion provided on the peripheral side surface of the core body may be extended to the resin molded portion and used as a resin injection groove.

A resin roller molding die according to the present invention is a molding die having a cylindrical die and core holding members attached to both ends of the cylindrical die. The core is placed in the mold while the core is placed in the mold, and both ends of the core are held by the core holding member, the resin is injected into the mold, and the core is cured. In a resin roller molding die that forms a cylindrical resin molding around the body,
The core holding member is provided with a core insertion hole opening outside the mold, or the core holding member is provided with a resin injection path communicating with the core insertion hole formed in the core holding member. It becomes.

According to the resin roller molding die of the present invention as described above, the core provided with the resin injection path as described above is mounted in the die, and both ends of the core are connected to the die. The core body is held by the core body holding member, and the core body is inserted from the resin injection path communicating with the core body insertion hole provided on the core body holding member and opening outside the mold. A resin is injected into the mold through the resin injection path and cured to form a cylindrical resin molding around the core. During this roller molding, the resin material for forming the resin molded portion is supplied from the end shaft portion of the core to the roller molding space from the peripheral side surface of the core of the resin molded portion through a resin injection path provided in the core. Since the resin is injected, the runner in which the resin in the resin injection path is hardened is not integrally formed on the outer surface of the resin molded portion. As described above, the man-hour related to the runner removal for reducing the runner removal failure is reduced. Can be omitted or reduced.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings of a molding die and a core, but the present invention is not limited to these embodiments. First,
In one embodiment of the present invention, as shown in FIG. 1, the molding die 100 includes a cylindrical die 13 and a pair of core holding members 14 a and 14 b attached to both ends of the cylindrical die 13. The cylindrical mold 13 and a pair of core holding members 14
a and 14b form a roller forming space 15. In the pair of core holding members 14a and 14b, core insertion holes 141a and 141b for inserting and holding respective end shaft portions 211a and 211b at both ends of the core 21 are formed. These cylindrical mold 13 and core holding members 14a, 14b
Consisting of any known material used for thermosetting resin molding, preferably, pre-hardened steel, hardened steel,
Nonmagnetic steel, carbon tool steel, corrosion resistant steel (stainless steel), and the like.

Next, as a basic form of the core body 21 held in the molding die 100, for example, FIG.
And (b) are applicable, but the present invention is not limited to these. Further, as the material of the core 21, any material known as the core of the resin roller, for example, a metal material or a synthetic resin material having conductivity is applicable.

As for the size of the molding die and the core as described above, the molding die and the core of the present invention can be applied to any size of a known resin roller. Generally, the size is 10 mm to 30 mm in diameter and 200 mm to 400 mm in length. The core 21 held by each of the core holding members 14a and 14b
The outer diameter of the end shaft portions 211a and 211b is 4 mm to 10 m.
m.

In the embodiment shown in FIG. 1, one of the core holding members 1 on the resin injection side of the molding die 100 is provided.
The core body insertion hole 141a of 4a is opened outside the mold,
The opening is provided with a nozzle touch portion 19 with which the resin injection nozzle 18 contacts. The molding die 10
The nozzle 21 is attached to the core 21 mounted in the
A resin injection path communicating with the opening 9 is provided. For example, as shown in FIG. 1 as one embodiment, the resin injection path provided in the core 21
Along with providing a hollow vertical hole portion 201 in the axial direction from
A horizontal hole 202 is provided in the radial direction of the core 21 from the tip of the vertical hole 201 so that the resin can be injected into the roller molding space 15 of the cylindrical mold 13, so that the core body end surface 212 is opened. In addition, a resin injection hole 20 that opens to the roller molding space 15 is provided on the peripheral side surface of the resin molding portion 213 of the core 21. As a specific configuration of the resin injection hole 20, the inner diameter of the vertical hole portion 201 provided in the axial direction from the core end surface 212 of the core body 21 is preferably larger in order to shorten the resin injection time, While taking into account the bending strength of the core 21 and depending on the outer diameter of the core 21,
m or more, and more preferably in the range of φ1 mm to φ3 mm. The cross section of the vertical hole portion 201 may not be circular, but the cross sectional area is preferably equivalent to the inner diameter in the case of the above circular shape. Also, the cross section of the horizontal hole portion 202 that opens from the vertical hole portion 201 into the molding space 15 of the cylindrical mold 13 has an inner diameter of φ depending on the outer diameter of the core body 21.
The range of 0.5 mm to 2 mm is preferable. In addition, it is necessary to take into consideration the number of the lateral hole portions 202 and the bending strength of the core body 21, but it is preferable that the number is not more than two. Further, the horizontal hole portion 202 does not necessarily need to be the tip of the vertical hole portion 201 as shown in the figure, but the shorter the vertical hole portion 201 is, the shorter the resin injection time is, and the less loss of the resin material is. Is preferred. Furthermore, when providing a plurality of horizontal hole portions 202, it is not necessary to provide them from the same position of the vertical hole portion 201. However, when providing two at the same position, it is possible to provide a radial through hole in the core body 21. Processing of the core body 21 is facilitated, while the side hole 2
It is advantageous to provide the core body 21 at a different position from the strength surface of the core body 21 in the 02 part.

The core 2 processed as described above
1 is a nozzle touch in which a resin injection hole 20 provided in a core 21 is provided in an outer opening of the core holding member 14a in a molding die 100 including a cylindrical mold 13 and core holding members 14a and 14b. The resin injection nozzle 18 is press-fitted to the nozzle touch portion 19 in a state where the resin injection hole 18
If a molded product is obtained by injecting a resin into a mold through heating and curing by heating, the resin material is directly filled into the roller molding space 15 from the resin injection nozzle 18 through the core 21. As shown in FIG. 2, the resulting molded article includes:
The runner to be removed is not formed. Therefore, the runner removing step can be omitted, and no defect accompanying the runner removal occurs, and a good product can be stably produced.

Further, for example, as shown in FIG.
Step 125 between the resin molding portion 213 and the end shaft portion 211
In the case of the core body 21 in which the core body 21 is formed, as shown in FIG. 3, the core body insertion hole 141a of the core body holding member 14a is formed to penetrate outside the mold, and the core body 21 is formed. The end surface 212 on the side where the resin injection hole 20 is provided is the core holding member 14a.
Can be mounted in a state where it is exposed to the outside of the mold from the core insertion hole 141a.
9 is processed into a semicircular cross section, and the resin injection nozzle 1
It is also possible to inject resin directly from 8 into the resin injection hole 20 of the core 21.

As shown in FIG. 4, a resin injection passage 16 communicating with the outside of the mold is formed from a core insertion hole 141a provided in the core holding member 14a on the resin injection side. The resin material injected from the nozzle touch portion 19 provided in the opening of the core body 21 is passed through the resin injection path 16.
A method of guiding the resin to the resin injection hole 20 provided as a resin injection path may be adopted. In this case, the resin in the resin injection path 16 of the core holding member 14a is
As shown in (a), the runner 17 is attached to the end face 21 of the core 21.
2, but can be easily removed by cutting along a core end surface 212 with a cutter or the like (FIG. 5B).

FIGS. 6 and 7 show another resin roller according to the present invention, in which a resin injection groove 22 serving as a resin injection path is formed on a peripheral side surface of the core body 21. Shaft 21
This is provided from 1 to the resin molded portion 213.
For example, as shown in FIG. 8, the resin roller 10 is used as a molding die 100 as a core holding member 14a on the resin injection side.
A core insertion hole 141 formed in the core holding member 14a.
a, which is formed with a resin injection path 16 communicating with the outside of the mold from a.
The core 21 formed with the core 2 is mounted in advance with the resin injection groove 22 communicating with the resin injection path 16 of the core holding member 14a. The resin injection nozzle 1
8 is pressed into contact with the roller molding space 15 through the resin injection path 16 of the core holding member 14a and the resin injection groove 22 of the core 21.
The inside of the core 21 is filled with a resin material and cured by heating.
Is formed by forming the resin molded portion 12 around the periphery of the substrate.

As described above, the resin injection groove 22 is
6 and 7, the runner 1 is formed by the resin in the resin injection path 16 of the core body holding member 14a, as shown in FIGS.
7 is formed so as to protrude from the end surface 212 of the core body 21, but if the cutter or the like is cut along the core body end surface 212, the runner 17 can be easily removed.

As a specific mode of the resin injection groove 22 formed on the peripheral side surface of the core body 21 as described above, the cross section thereof is preferably large in order to shorten the resin injection time. It is necessary to consider the bending strength of Further, in the case of the type of bearing for holding the end of the core body in an environment where the resin roller 10 is used, particularly in the case of an oil-impregnated bearing, the resin injection groove 22 wears the inner surface of the oil-impregnated bearing, so that it cannot be made too large. Even when the cross section of the resin injection groove 22 cannot be made large for the above reason, it is possible to reduce the resin injection time by reducing the viscosity of the injected resin. In consideration of the above situation, the cross-sectional area of the resin injection groove 22 is preferably 0.25 mm ² or more, and 0.64 m ² or more.
The range of m ^{2 to 4} mm ² is more preferable.

Further, in the above case, the resin injection path 16 formed in the core holding member 14a can communicate with the resin injection groove 22 formed in the core 21 held by the core holding member 14a. Need to be formed. For example, when the D-cut portion 214 is formed on the end shaft portion 211 of the core body 21 as shown in the figure, the resin injection groove 22 of the core body 21 held on the core body holding member 14a is formed. Since the position is always constant, the resin injection path 1 of the core holding member 14a is
6 may be provided at a predetermined position corresponding to the position of the resin injection groove 22 of the core body 21 with a predetermined size. The core 21
The D-cut part 214 formed in the resin roller 10
When the is rotated by a driving means such as a motor, a gear for transmitting a driving force from the motor or the like is attached and provided as a detent. On the other hand, when the D cut portion 214 is not formed on the core 21 as shown in the figure,
Since it is difficult to position and attach the core body 21 to the core body holding member 14a at a predetermined position around the axis thereof, the resin injection groove 22 formed in the core body 21 is not necessarily at a fixed position. Not be. In this case, if the resin injection path 16 of the core body holding member 14a is provided so as to open over the entire surface of the core body end surface 212, the resin injection groove 21 of the core body holding member 14a can be located at any position. The core 21 can be held by the core holding member 14a in a state where the core 21 communicates with the resin injection path 16.

The sectional shape of the resin injection groove 22 as the resin injection path provided in the core body 21 does not need to be square as shown in FIG. For example, as shown in FIGS. 9 and 10, a D-cut portion 214 provided for attaching a gear or the like to the roller end shaft portion 211 of the resin roller 10 is located at a position reaching the resin molded portion 213 in the axial direction of the core body 21. It is also possible to form the resin injection groove 22 by extending the length up to that. As shown in FIG. 11, for example, the resin roller 10 is formed by forming a core having a shape corresponding to the shape of the end shaft 211 of the core 21 having the D-cut portion 214 formed on the core holding member 14a on the resin injection side. In addition to forming the body insertion hole 141a, the resin injection path 16 communicating from the portion corresponding to the D-cut portion 214 of the core body insertion hole 14a to the outside of the mold is formed. A core 21 having a resin injection groove 22 formed by extending a D-cut portion 214 as a resin injection groove is attached, and the resin injection groove 22 is attached to the core holding member 1.
4a, the resin injection nozzle 18 is pressed against a nozzle touch portion 19 provided at the opening of the resin injection path 16 of the core holding member 14a, and the core holding member 1
A resin material is filled in the roller molding space 15 through the resin injection path 16 of 4 a and the resin injection groove 22 of the core 21, and is heated and cured to form the resin molded portion 12 around the core 21. . In this case, it is not very difficult to cut the runner 17 formed in the D cut portion 214 of the resin roller 10 after molding as shown in FIG. 9 in a later step as shown in FIG.

As described above, according to the present invention, when the resin molding portion 12 is formed around the core 21 of the resin roller 10, the resin injection hole 20 or the resin injection groove 22 formed in the core 21 is formed. Mold 100 using injection path
Is filled with the resin in the roller molding space 15 of the resin molding portion 15 as in the conventional case.
The liner 17 is not integrally formed with the resin in the resin injection path 16 of the core holding member 14 on the outer surface of the mold. Therefore, man-hours related to runner removal for reducing runner removal failure can be omitted or reduced. In order to inject into the mold in a short time, the core 2
It is also possible to provide two or more resin injection paths such as the resin injection hole 20 and the resin injection groove 22 in 1, and in this case, needless to say, each resin injection path can be of a different embodiment.

Hereinafter, a specific method for molding the resin roller 10 using the core 21 and the molding die 100 as described above will be described.

For example, as a resin material for forming a resin molded portion, a curable composition obtained by blending a polysiloxane-based curing agent and a conductivity-imparting material (carbon black) with an allylated polyoxypropylene-based polymer, In a liquid resin injection / injection machine, when a roller having an outer diameter of a core of 8 mm, an outer diameter of a roller of 16 mm, and a length of a resin molding section of 250 mm is formed, the viscosity of the compounded resin material is determined by the conductivity imparting property. Depending on the number of parts mixed, 200-800 poise,
The injection pressure at the time of injection is 0.5 MPa to 4 MPa. As for the direction of the molding die 100 at the time of injection, it is preferable that the longitudinal direction of the die 100 is set upright so that the core holding member 14a on the resin injection side is downward, and the injection is performed from the lower part of the die.

The heating of the mold can be performed by any conventionally known method. Specifically, for example, a method of heating in a heating furnace provided with a heating fan, a method of arranging an electric heater around a mold and heating, or a method of arranging an induction heating coil around the mold and heating. There are methods.

As the temperature of the mold, any temperature at which the resin material can be injected and heat-cured can be selected. When the resin is injected, the temperature at which the resin is easily injected and which does not harden, for example, About 20 ° C to 80 ° C is preferable. Further, the heating temperature of the resin depends on the amount of the curing retarder and the like to be blended with the resin, but is preferably about 80 ° C to 200 ° C.

As a molding resin material used for molding the resin roller of the present invention, a thermosetting resin is used. For example, silicone, urethane, acrylonitrile / butadiene copolymer (NBR), ethylene / propylene / diene / methylene copolymer (EPDM) and the like can be used.

[0029] Other various additives can be added to the thermosetting resin as needed. For example, if a resistance control agent such as carbon black is added, the electric resistance of the roller can be controlled.

As the thermosetting resin material, a curable composition described below can also be used. Since the molding resin composed of the reaction cured product of the curable composition has a particularly flexible structure,
Even if the thickness of the resin molded portion is reduced, the elastic effect is sufficiently exhibited. In addition, when containing an oxyalkylene unit, it is easy to handle because it has a low viscosity before curing, and when it contains a saturated hydrocarbon unit, it has a low water absorption and has little change in volume and roller resistance even in a high humidity environment. It is preferred in that respect.

That is, as the thermosetting resin material,
(A) a polymer having at least one alkenyl group in the molecule, wherein the repeating unit constituting the main chain is mainly composed of an oxyalkylene unit or a saturated hydrocarbon unit; and (B) at least two hydrosilyl groups in the molecule. It is preferable to use a curable composition containing a group-containing curing agent, (C) a hydrosilylation catalyst, and (D) a conductivity-imparting agent as main components.

The thermosetting resin material is added with a material for adjusting a thermosetting reaction, such as a curing agent, a curing accelerator, a curing retarder, and the like, if necessary. If necessary, an organic or inorganic filler can be added. Furthermore, various organic or inorganic pigments, thickeners, release agents, and the like can be added as necessary.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, non-limiting embodiments of the present invention will be described. Using the molding die 100 having the structure shown in FIG.
Roller outer diameter is φ16mm, resin molding length is 250m
m of the resin roller was formed. The outer diameter of the core end shaft 211 is 8 mm, and the inner diameter of the vertical hole 201 of the resin injection hole 20 is φ.
2 mm and the roller forming space 15 of the cylindrical mold 13.
A hole having a diameter of 1 mm is formed as
2 were opened in the outer diameter direction. The thermosetting resin material used was a compounded resin shown in Table 1 below, and had a viscosity of 600 poise. The thermosetting resin material was injected from the lower part of the mold by raising the length of the mold vertically at an injection pressure of 4 MPa in an injection molding machine for liquid resin. Heating the mold
By heating in a heating furnace provided with a heating fan, the atmosphere temperature in the heating furnace is set to 140 ° C., and after heating for 20 minutes, a mold release load of 20 kg is applied from the mold in the axial direction of the molded product. While releasing the mold in about 10 seconds, a molded product was obtained. As a result, in the obtained resin roller, the resin molded portion was favorably molded, and no runner was generated.

[0034]

[Table 1]

[0035]

According to the present invention, as a resin roller having a resin molded portion formed around a core, a resin injection path is provided in the core, and a resin material is injected from here into a molding space of a mold. As a result, the runner is not integrally formed on the outer surface of the resin molded part, and after the molding, a part of the runner remains on the outer surface of the resin molded part or the one part of the resin molded part due to the removal of the runner. Since the part is not lost, a troublesome and precise runner removal step can be omitted or reduced, and a good product can be stably obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view showing a state in which a core of a molding die is mounted according to an embodiment of the present invention.

FIG. 2 is an explanatory cross-sectional view of a resin roller molded by a molding die shown in FIG.

FIG. 3 is an explanatory cross-sectional view of a state in which a core of a molding die according to one embodiment of the present invention is mounted.

FIG. 4 is an explanatory cross-sectional view showing a state in which a core of a molding die is mounted according to one embodiment of the present invention.

5A and 5B are explanatory cross-sectional views of a resin roller formed by a molding die shown in FIG. 4 after molding, in which FIG. 5A shows a state in which a runner is attached immediately after molding, and FIG. .

FIG. 6 is a perspective view of a resin roller provided with a resin injection groove in a core according to an embodiment of the present invention.

7 is an explanatory cross-sectional view of the resin roller shown in FIG. 6 in a state where a runner is attached immediately after molding.

8 is an explanatory sectional view of a state where a core of a molding die of the resin roller shown in FIGS. 6 and 7 is mounted. FIG.

FIG. 9 shows the D of the core in one embodiment of the present invention.
It is a perspective view of the resin roller which extended the cut part and became the resin injection groove.

10 is an explanatory cross-sectional view of the resin roller shown in FIG. 9 in a state where a runner is attached immediately after molding.

FIG. 11 is an explanatory sectional view showing a state where a core of a molding die of the resin roller shown in FIGS. 9 and 10 is mounted.

FIG. 12 is a perspective view of a general resin roller.

FIGS. 13A and 13B are cross-sectional explanatory views of a conventional general resin roller.

FIG. 14 is an explanatory sectional view of a conventional resin roller molding die.

15A and 15B are cross-sectional explanatory views of a resin roller formed by a conventional molding die, wherein FIG. 15A shows a state immediately after molding and a runner is attached, and FIGS. 15B and 15C show states after the runner is removed. (B) shows a state in which a part of the runner remains when the runner is removed, and (c) shows a state in which the edge of the resin molded portion is lost when the runner is removed.

[Explanation of symbols]

10: resin roller, 12: resin molded part, 13: cylindrical mold, 14: core holding member, 15: roller molding space, 1
6: resin injection path, 17: runner, 18: resin injection nozzle, 19: nozzle touch portion, 20: resin injection hole, 21:
Core, 22: resin injection groove, 100: molding die, 121:
Resin molded part end face, 122: Resin molded part edge, 201: Vertical hole part, 202: Horizontal hole part, 211: Core end shaft part, 212:
Core end face, 213: resin molded portion, 214: D cut portion, 215: step.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/08 501 G03G 15/08 501D 4F204 15/16 103 15/16 103 // B29K 105: 20 B29K 105 : 20 B29L 31:32 B29L 31:32 F-term (Reference) 2H003 BB11 CC05 2H032 AA05 BA07 BA15 2H077 AD06 FA13 3J103 AA02 AA13 AA23 EA02 FA15 GA02 GA52 GA57 GA58 GA60 GA74 HA03 HA41 4F202 AD18 AH04 CA01 CK01 CB01Q04 C01CB05 AH04 EA03 EA04 EB01 EB12 EF27 EK17 EK24

Claims (8)

[Claims] 1. A resin roller having a cylindrical resin molded portion formed around a core, wherein a resin injection path is provided from an end shaft of the core to a resin molded portion. . 2. The resin roller according to claim 1, wherein a hollow resin injection hole is provided as an opening in the end surface of the core body and the peripheral side surface of the resin molded portion. 3. The resin roller according to claim 1, wherein a resin injection groove is provided on a peripheral side surface from an end shaft portion of the core body to a resin molding portion as the resin injection path. 4. The resin roller according to claim 3, wherein a D-cut portion provided on an end shaft portion of the core body extends to a resin molding portion as the resin injection groove. 5. A resin roller core manufactured by forming a cylindrical resin molded portion around the resin roller, wherein a resin injection path is provided from an end shaft portion of the core to the resin molded portion. Core body. 6. A molding die having a cylindrical die and core holding members attached to both ends of the cylindrical die,
Placing a core in the mold, holding both ends of the core in the core holding member, mounting the core in the mold, injecting resin into the mold, and curing. In a resin roller molding die that forms a cylindrical resin molded portion around a core, the core holding member is provided with a core insertion hole that opens to the outside of the die. Roller molding die. 7. A molding die having a cylindrical die and core holding members attached to both ends of the cylindrical die,
Placing a core in the mold, holding both ends of the core in the core holding member, mounting the core in the mold, injecting resin into the mold, and curing. In a resin roller molding die that forms a cylindrical resin molded portion around a core, the core holding member communicates with a core insertion hole formed in the core holding member, and is provided outside the die. A resin roller molding die, characterized by having a resin injection path that opens. 8. A core body is disposed in a molding die having a cylindrical mold and core body holding members attached to both ends of the cylindrical mold, and both ends of the core body are attached to the core body. A method of forming a resin roller in which a cylindrical body is formed around a core body by mounting a core body in a mold held by a holding member, injecting a resin into the mold, and curing the core body. , Wherein a resin is injected into a mold through a resin injection path provided in the core body.