JP4990600B2 - Rubber roller manufacturing equipment - Google Patents

Description

  The present invention relates to a developing roller used for electrophotographic image formation. The present invention also relates to a rubber roller manufacturing apparatus in which a rubber material is injected into a molding die and cured to obtain a rubber roller.

  Generally, a rubber roller is manufactured by injecting a rubber material into a molding die. For this purpose, the molding die is composed of at least three members, a hollow cylindrical die body (pipe type) and pieces attached to both ends thereof. When injecting and curing the rubber material, the clamps on both ends of the pipe mold are clamped by a clamping member from above and below with a cylinder, a spring, a screw or the like. At this time, since both end surfaces of the molding die and the clamping member are in contact with each other in a plane, if the parallelism between the end surface of the molding die and the surface of the clamping member is poor, the clamping member and the molding die end surface are uniform. There is a case where it does not hit, and a partial load is applied in the axial direction of the molding die due to contact with one piece. At this time, a bending moment is generated in the molding die and the molding die is bent, or the fitting state between the pipe die and the piece of the molding die is changed. As a result, the molded rubber roller is also bent, and the runout accuracy may deteriorate. This deterioration in shake accuracy has caused uneven electrical resistance and image defects in rollers in electrophotographic technology.

  In addition, if the flat surfaces of the molding die and the clamping member do not contact each other uniformly, a gap occurs in this portion, and in the worst case, a problem of material leakage may occur.

  As a conventional technique, there is a method of clamping using an injection molding machine (C type) using a spherical bearing (see Patent Document 1). However, in this case, since the slide guide for clamping the mold is disposed between the spherical bearing and the mold, the movement amount of the spherical bearing is restricted by the slide guide.

In addition, in the technique of performing mold clamping using a spherical bearing, there is a case where it is not possible to suppress an uneven load from being applied to the molding die only by movement in the spherical direction.
JP-A-10-217302

  An object of the present invention is to provide a manufacturing apparatus capable of suppressing the application of an unbalanced load to a molding die during mold clamping, preventing the bending of the die, and manufacturing a rubber roller with high runout accuracy.

According to the present invention, it has a molding die comprising at least three members of a cylindrical die body and pieces A and B fitted to both ends thereof, and an axial core body is disposed at the center inside the molding die, In a rubber roller manufacturing apparatus for injecting a rubber material from one piece A into a mold body and curing and molding the rubber material,
A mold clamping device for fixing the mold body and the pieces A and B during the injection;
A mold clamping tip member capable of contacting the piece B, and a slide means capable of sliding the mold clamping tip member on the cylindrical central axis of the mold body to contact the piece B; Have
A mold clamping angle adjusting mechanism for adjusting the angle of the mold clamping tip member, and a mold clamping position for adjusting the position of the mold clamping tip member in a direction perpendicular to the cylindrical central axis of the mold body. An apparatus for manufacturing a rubber roller is provided.

  According to the present invention, there is provided a manufacturing apparatus capable of manufacturing a rubber roller with high run-out accuracy by suppressing an uneven load from being applied to a molding die during mold clamping, preventing the deflection of the die.

By the present invention lever may swing accuracy, unevenness of the electric resistance is suppressed with, it is possible to obtain the developing roller of the image defect can be prevented.

  The rubber roller manufacturing apparatus of the present invention has a molding die and a clamping device for clamping the molding die. The molding die has a hollow cylindrical mold body and pieces (at least two pieces) to be fitted to both ends of the mold body.

  One piece (referred to as piece A) is a piece for injecting a rubber material, and a rubber material for forming a rubber roller is injected into a molding die through a through hole provided in the piece A.

  The mold clamping device has slide means that can slide the mold clamping tip member into contact with the other piece (referred to as piece B). When the mold body and the pieces A and B are clamped by the angle adjustment mechanism and the position adjustment mechanism, the slide means can move on the cylindrical central axis of the molding mold and can be clamped.

  The sliding means has a mold clamping angle adjusting mechanism and a mold clamping position adjusting mechanism in order to bring the mold clamping tip member into close contact with the piece while preventing eccentricity of the load during mold clamping.

  Speaking of the part where the die clamping tip member directly contacts the piece, the angle formed by the die clamping tip member with respect to the piece can be adjusted around the die clamping tip member side as close as possible to the piece end surface of the molding die. It is preferable to provide an angle adjustment mechanism. Further, it is preferable that a position adjusting mechanism capable of adjusting the position of the mold clamping tip member is provided on the mold clamping tip member side as close as possible to the end face of the molding die. By having the mold clamping angle adjusting mechanism and the mold clamping position adjusting mechanism, it is possible to deal with mold end faces that change for each mold.

  In this way, the molding die and clamping device can be applied uniformly on the mold center axis on a flat surface, so that it is possible to suppress the application of an offset load to the molding die end face and to suppress the generation of bending moments. To do. For this reason, the bending of the molding die is suppressed, and accordingly, the rubber roller obtained by molding the central core (shaft core) is also straightened, and the deflection accuracy is improved.

[Clamping angle adjustment mechanism]
In the present invention, examples of the mold clamping angle adjusting mechanism include a spherical bearing and a spherical movement. In particular, in a molding die composed of at least three members of a cylindrical die body and pieces A and B fitted to both ends thereof, when the mold is clamped, the tip member of the mold clamping device is brought into contact with the piece end surface that comes into contact. On the other hand, when it is arranged at a position where the tip member and the mold center axis deviate when assuming the mold center axis in the longitudinal direction, a spherical bearing is preferable because an angle change occurs due to the combination.

  When the mold clamping angle adjusting mechanism is a spherical bearing, a load is applied to the piece B from the driving device of the sliding means through the spherical bearing and the mold clamping tip member in this order. The mold clamping tip member is disposed in close contact with the end surface of the piece B through a spherical bearing having an angle adjusting action.

  In addition, as another method for providing the effect of the angle adjustment mechanism, for example, there is a method in which the contact portion between the molding die and the clamping device is a combination of a tapered surface and a convex spherical surface. The taper angle should just be comprised so that the center of a taper part may make the contact of the tangent of a convex spherical surface.

  The angle adjustment mechanism adjusts the angle formed by the mold clamping tip member with respect to the central axis of the cylindrical mold. Thereby, it is possible to make the contact with the die clamping tip member in contact with the outward end face of the piece uniform. The mold clamping tip member is angle-adjusted according to the angle of the outer end face of the piece B.

(Clamping position adjustment mechanism)
The mold clamping position adjustment mechanism enables the mold clamping tip member to be moved in a direction perpendicular to the mold center axis.

  Examples of the mold clamping position adjusting mechanism include a method in which a gap is formed in the connecting portion between the mold clamping tip member that contacts the piece B and the angle adjustable clamping body, and an elastic body is used in the gap.

  When a spherical bearing is used for the mold clamping angle adjusting mechanism, the mold clamping position adjusting mechanism can be formed as follows. That is, a shaft is provided on the clamping end member, a hole for inserting this shaft is provided inside the spherical bearing, and a gap is provided between the shaft and the hole. An elastic body can be arranged in the circumferential direction. In this case, the mold clamping tip member axis and the elastic body arranged around the shaft are arranged in the shaft hole portion of the spherical bearing, and the mold clamping central axis of the mold clamping tip member (center axis of the clamping force) is It can be moved so as to coincide with the central axis of the cylindrical mold main body and the pieces A and B fitted to both ends thereof (cylindrical central axis of the mold main body).

  As the elastic body, an O-ring is preferably used from the viewpoint that it is suitable for being disposed in a cylindrical gap between the spherical bearing and the shaft portion of the tip member. For example, an elastic resin, a gel-like body, or a structure sealed with a liquid material is provided in the circumferential direction in the cylindrical gap between the inner surface of the spherical bearing and the shaft portion of the tip member. You may arrange in.

  Here, the elastic seal is an elastic resin, a gel-like body, or a liquid material sealing structure capable of filling a cylindrical gap.

  With the mold clamping position adjusting mechanism, it is possible to absorb the axial deviation in the normal direction with respect to the central axis of the mold body cylinder at the contact portion between the mold clamping tip member and the mold.

[Sliding means]
An air cylinder, a hydraulic cylinder, a spring, a screw, or the like can be used as a driving device for the sliding means.

[Production method of rubber roller]
A shaft core is arranged in the center of the molding die consisting of at least three members of a cylindrical die body and pieces A and B fitted to both ends thereof, and a rubber material is fed from one piece A into the die body. The rubber roller can be manufactured by pouring, curing and molding.

[Rubber material]
In the present invention, a liquid rubber material is preferred as the rubber material because the rubber material is injected into the cylindrical mold. Examples of the liquid rubber material include silicone rubber, urethane rubber, chloroprene rubber, and the like. Silicone rubber that can provide good setting properties when used as a roller is particularly preferable.

[Development roller]
With the rubber roller manufacturing apparatus of the present invention, a rubber roller suitable for a developing roller mounted on a developing unit of an electrophotographic apparatus can be obtained.

  As described above, in the rubber roller manufacturing apparatus of the present invention, the slide means having the mold clamping angle adjusting mechanism and the mold clamping position adjusting mechanism is used so that the mold clamping tip member is in close contact with the piece during mold clamping. Thereby, it is possible to suppress an offset load from being applied to the molding die (piece). Thereby, since a deformation | transformation of a metal mold | die is suppressed, a rubber roller with good runout accuracy can be shape | molded. The rubber roller is highly compatible as a developing roller.

  An embodiment in which the apparatus for manufacturing a rubber roller of the present invention is applied to molding of a developing roller for electrophotography will be described with reference to the drawings.

[Example 1]
As shown in FIG. 1, a die body 2a having an inner shape of a cylindrical shape with an inner diameter of 12 mm and a length of 240 mm, and an upper piece 1 (piece B) and a lower piece 3 (pieces) fitted to both ends of the mold body. A molding die comprising the three constituent members A) was used.

  The lower piece main body is provided with eight holes with a diameter of 1.8 mm equally distributed in the circumferential direction as material injection holes. The touch piece has a hole with a diameter of 5 mm in the center.

  The material of the molding die is prehardened steel in all the constituent members.

  A shaft core body 4 having a diameter of 6 mm and a length of 250 mm was inserted into the molding die.

  As shown in FIG. 2 and partially enlarged in FIG. 3, the mold clamping device is an angle-adjustable type (the upper piece 1 and the mold clamping tip member 6b are slidably in close contact with the piece. The contact adjustment) and the position adjustment type (O-ring 9). The contact site between the mold clamping device and the mold is a flat surface. By having the spherical bearing 5 and the O-ring 9, the contact between the upper piece 1 and the mold clamping tip member 6b becomes good. For the spherical bearing, model number SB8 (manufactured by THK Corporation) was used.

  The mold clamping device includes a spherical bearing 5, an O-ring 9, a fixed plate (backup plate) 6a, a tightening tip member 6b, an air cylinder 6c, a shaft 6d, and a fixed plate 6e. The fixed plate 6a and the movable plate 6b are flat plates.

  The upper piece 1, the pipe die (die body) 2a, and the lower piece 3 are fixed between the fixing plate 6a of the mold clamping device and the clamping tip member (movable plate) 6b, and the air cylinder is clamped to the mold clamping device. The product was extruded in the direction of the central axis 8 and clamped. The clamping force was 590N.

  A thermosetting liquid silicone rubber was injected into the molding die and cured at 100 ° C. The liquid silicone rubber used for molding is a two-component mixed thermosetting silicone rubber having a viscosity of 150 Pa · s. Moreover, carbon black is blended in order to give conductivity.

  The runout of the rubber roller obtained at a point of 10 mm from both ends of the rubber and at three points at the center was measured. To measure the runout, place a rubber roller on the bearing, measure 100 points in the circumferential direction from the reference to the outer diameter of the roller using a laser dimension measuring instrument (manufactured by KEYENCE CORPORATION), and measure from the maximum value to the minimum value. The value obtained by subtracting the value was evaluated as shake. It is preferable that the center part has a deflection of 25 μm or less and a deflection at both ends of 15 μm or less.

[Comparative Example 1]
An apparatus having the structure shown in FIG. 4 was used as the mold clamping apparatus. This mold clamping apparatus is a fixed type, and the contact part with a metal mold | die is a plane.

  Except for this, a rubber roller was prepared in the same manner as in Example 1, and the runout was measured.

As shown in Table 1, the rubber roller of Example 1 has less deflection than Comparative Example 1. In particular, Comparative Example 1 shows that the center portion has a large deflection and the mold is bent. In addition,
In Comparative Example 1, as shown in FIG. 5, the contact with the upper piece 1 is different for each mold due to the clamping tip member 6 b, and an angle θ is generated. Therefore, it is difficult to make the contact uniform in all molds.

It is a schematic diagram which shows an example of the shaping die which can be used by this invention. It is a schematic diagram which shows an example of the shaping die which can be used by this invention, and a clamping device. It is the elements on larger scale of the mold clamping apparatus shown in FIG. It is a schematic diagram for demonstrating the clamping apparatus used in the comparative example 1. It is a schematic diagram for demonstrating the eccentric load per piece in the mold clamping apparatus used in the comparative example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper piece 2a Cylindrical metal mold body 2b Mold central axis 3 Lower piece 4 Shaft body 5 Spherical bearing 6a Clamping device fixing plate 6b Clamping tip member 6c Clamping device air cylinder 6d Clamping device Shaft 6e Back-up plate of mold clamping device 8 Mold clamping device fixing plate central axis 9 O-ring θ angle

Claims (6)

A cylindrical mold body and a molding die composed of at least three members A and B fitted to both ends of the cylindrical mold body, and an axial core is disposed at the center of the interior of the molding mold; In a rubber roller manufacturing apparatus for injecting a rubber material from one piece A into the mold and curing and molding the rubber material,
A mold clamping device for fixing the mold body and the pieces A and B during the injection;
The mold clamping device is capable of coming into contact with the piece B, and a mold clamping tip member capable of coming into contact with the piece B, and sliding means capable of sliding the mold clamping tip member on the cylindrical central axis of the mold body And
A mold clamping angle adjusting mechanism for adjusting the angle of the mold clamping tip member, and a mold clamping position for adjusting the position of the mold clamping tip member in a direction perpendicular to the cylindrical central axis of the mold body. An apparatus for manufacturing a rubber roller, comprising: an adjustment mechanism.   The rubber roller manufacturing apparatus according to claim 1, wherein the mold clamping angle adjusting mechanism is configured such that the tip member comes into contact with the piece B by a spherical bearing.   3. The rubber roller according to claim 2, wherein the mold clamping tip member includes a shaft inserted into the spherical bearing, and the mold clamping position adjusting mechanism includes an elastic body disposed in a circumferential direction around the shaft. Manufacturing equipment.   The rubber roller manufacturing apparatus according to claim 3, wherein the elastic body is an O-ring or an elastic seal.   The rubber roller manufacturing apparatus according to any one of claims 1 to 4, wherein the sliding means includes at least one selected from the group consisting of an air cylinder, a hydraulic cylinder, a spring, and a screw.   6. The rubber roller manufacturing apparatus according to claim 1, wherein the rubber material is a liquid rubber material.

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