KR20100098051A - Casting mould for manufacturing printer poller and casting method using the casting mould - Google Patents

Abstract

PURPOSE: A casting mold for casting a printing roller and the casting method of the printing roller using the same are provided to reduce the eccentric phenomenon of a rotary shaft by minimizing the volume of a material injecting hole. CONSTITUTION: A casting mold for casting a printing roller includes a lower mold(110) and an upper mold. A lower molding space(112) is placed in the lower mold, and an upper molding space is placed in the upper mold. The upper molding space corresponds to the upper external circumference of the printing roller. The upper molding space faces the lower molding space by combining the upper mold and the lower mold. An injection hole for materials is formed in the upper mold.

Description

Casting mold body for casting of roller for printer and casting method of printer roller using the casting mold body {CASTING MOULD FOR MANUFACTURING PRINTER POLLER AND CASTING METHOD USING THE CASTING MOULD}

The present invention relates to a casting mold body for casting a roller for a printer and a casting method for a roller for a printer using the casting mold body, and more particularly, casting for casting of a roller for a printer manufactured through a low temperature reaction under atmospheric pressure. A casting method of a roller for a printer using a mold body and the said casting mold body.

In printing machines such as copiers, printers, and facsimiles, speeding up output speed and improving print quality are very important factors. In order to meet these demands, in each process such as development cleaning, paper supply, and paper conveyance, a charge roller, a supply roller, a development roller, a feed roller, a convey roller Transfer rollers play an important role.

The rollers described above have to be excellent in mechanical properties such as wear resistance and surface roughness according to the continuous output of the printing machine described above, and in some cases, excellent conductivity may be required for a specific purpose. For example, rollers requiring conductivity include a developing roller, a charging roller, a toner supply roller, and the like.

In particular, the conductive rollers for laser printers include acrylonitrile butadiene rubber (NBR) containing carbon black, metal oxides and ionic compounds, ethylene propylene diene rubber, EPDM), epichlorohydrin rubber (ECO), silicone rubber, polyurethane, and the like are known. That is, the conductive roller for laser printers generally uses rubber and polyurethane as its main materials.

Meanwhile, a rubber roller manufactured by mixing acrylonitrile butadiene rubber (NBR), ethylene propylene diene rubber (EPDM), epichlorohydrin rubber (ECO), and silicone rubber In the manufacturing method, first, the roller shaft coated with the adhesive is placed in a mold, and the above-described materials are injected into the injection mold at a high temperature and high pressure to form a roller, and then cured at a constant temperature. A rubber roller is manufactured.

However, in the case of rubber rollers, when the material is injected into an injection mold, high temperature and high pressure must be maintained, so that the hardness of the rubber roller after molding may be as high as 50 degrees or more. In the case of a roller in contact with a sensitive toner or the like, a roller of relatively high hardness may adversely affect the surface of the roller.

In contrast, a roller made of polyurethane can reduce the hardness to about 40 degrees. However, since polyurethane is hardened at a temperature of about 7-80 ° C., it can be said that injection molding is difficult at high temperature and high pressure, such as rubber, and a roller mainly using polyurethane is manufactured according to a casting method.

That is, the liquid polyurethane is poured into a mold for roller production, and the temperature of the mold is increased to about 7-80 ° C. to cure the polyurethane in the mold. However, conventional molds for producing polyurethane rollers are formed in a single piece and provide a U-shaped mold space, so that the initial molding by casting cannot be used as a roller for a printer. It's a big departure.

Therefore, in order to form the final product having the desired diameter from the initial molding of the polyurethane obtained from the conventional U-shaped mold, it is required to go through several polishing operations, and the loss of material caused by the polishing work is a large economic vulnerability. There is this.

In addition, since a molded article obtained from a conventional mold is formed in a semi-circular shape in correspondence with a non-spherical U-shaped mold, the roller shaft is eccentric in the polishing operation while rotating the roller shaft as a rotating shaft. The shaft for the roller can be bent, and the printing quality can be degraded when using such a product in a printer.

The present invention is directed to casting a roller for a printer that can minimize the loss of material due to repeated polishing to form a final product having a desired diameter from the original molding of polyurethane produced by casting into a U-shaped mold. Provided are a casting method for a roller for a printer using a casting mold body and a casting mold body.

According to the present invention, a cross section of an initial molding of polyurethane cast using a U-shaped mold may be formed in a hemispherical shape, and the roller shaft may be eccentric when polishing is performed while rotating the roller shaft as a rotation axis. Provided are a casting mold body for casting a roller for a printer that can prevent the bending of a roller shaft, and a casting method for a roller for a printer using the casting mold body.

According to one exemplary embodiment of the present invention, a casting mold body for casting of a roller for a printer manufactured through a low temperature reaction under atmospheric pressure includes a lower mold and an upper mold.

The lower mold has a lower mold space formed to correspond to the lower outer circumferential surface of the roller for printer, and the upper mold has an upper mold space formed to correspond to the upper outer circumferential surface of the printer roller, and has a lower mold space facing the upper mold space and the lower mold space. By combining with the mold, an inner space corresponding to the shape of the roller for the printer is formed, and a material injection hole is formed through which is connected to the inner space.

Since the shape of the inner surface of the upper and lower molds has a circular shape approximately similar to the cross section of the printer roller to be finally produced, the cast product can also be cast approximately equal to that cross section of the final product of the printer roller.

In addition, the material injection hole into which the urethane material is injected is also provided in a minimally open form, rather than a U-shaped mold, which is entirely open at the top, so that the loss of material that may occur during polishing operation is minimized. Since the size of the protruding portion due to the material injection hole is minimized as described above, the eccentricity of the roller shaft which may occur during the polishing operation to remove it is minimized, and the bending of the roller shaft due to the polishing is minimized. It can reduce the occurrence.

In addition, the shape of the material injection hole is formed long in the longitudinal direction of the printer roller, and in particular, the width of the center portion of the material injection hole is made wider than the width of the outer portion of the material injection hole, whereby the urethane material forming the printer roller is relatively formed. By injecting into the inner space of the mold body through the wide central portion, it is possible to prevent the urethane material from overflowing to either side due to the viscosity of the urethane material.

In addition, when the urethane material forming the roller for the printer is injected into the interior space through the material injection hole having the above-described shape, the air in the internal space can be discharged to the outside of the mold relatively freely through the material injection hole formed long. Therefore, it is possible to minimize the generation of bubbles that can reduce the surface roughness on the surface and the surface of the cured urethane material.

According to another exemplary embodiment of the present invention, a method for casting a roller for a printer manufactured through a low temperature reaction under atmospheric pressure includes a lower mold having a lower mold space formed so as to correspond to a lower outer circumferential surface of the roller for a printer, and a printer. Providing an upper mold having a material injection hole formed to be connected to the upper mold space and the upper mold space so as to correspond to the upper outer circumferential surface of the roller, and arranging the shaft for the roller on the lower mold side by side with the lower mold space In the step, the upper mold space and the lower mold space facing each other to form an inner space corresponding to the shape of the roller for the printer, the step of combining the lower mold and the upper mold, the urethane material forming the roller for the printer through the material injection hole Injecting into the inner space, curing the urethane material provided in the inner space, and Qualified may include the step of stripping the polyurethane material.

At this time, the material injection hole is preferably formed long along the longitudinal direction of the roller for the printer, in particular, the width of the center portion of the material injection hole is formed wider than the width of the outer portion of the material injection hole, the urethane material is injected through this portion As a result, the air in the mold inner space can be easily discharged to the outside.

As mentioned above, after inject | pouring a urethane material into a casting body, it can hold | maintain for a predetermined time at the temperature of 70-80 degreeC, and can harden the injected urethane material.

Then, when demolding the cured urethane material from the mold, the upper mold can be separated from the lower mold, the roller shaft can be moved from the lower mold, and the cured urethane material can be demolded.

Alternatively, the upper mold may be separated from the lower mold, and the cured urethane material may be pushed out of the material injection hole to demold the cured urethane material from the upper mold. In this case, the force applied to the roller shaft by the weight of the cured urethane material is minimized, thereby preventing the roller shaft from bending.

After demolding the cured urethane material from the mold by the above-described method, it is possible to remove the protruding portion formed by the material injection hole among the cured urethane material, and at this time, while rotating the roller shaft, the cured urethane The material is finally polished to the diameter of the roller to be produced.

Casting method of the printer roller using the casting mold body and the casting mold body for the casting of the roller for the printer of the present invention is minimal waste of material generated during polishing compared to the product manufactured using a conventional U-shaped mold You can do it.

Casting method of the printer roller using the casting mold body and the casting mold body for the casting of the printer roller of the present invention can minimize the volume of the material injection hole in which the urethane stock solution is injected during the casting of the printer roller to thereby occur during polishing It is possible to minimize the eccentricity of the roller shaft which is a rotating shaft, thereby preventing the bending of the roller shaft.

Casting method of the printer roller using the casting mold body and the casting mold body for the casting of the roller for the printer of the present invention, the material injection hole into which the urethane stock solution is injected is formed long to minimize the generation of bubbles in the roller for the printer In addition, it is possible to manufacture a roller for a printer having improved surface properties, thereby preventing the printing of a specific portion during printing.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or limited by the embodiments. For reference, in the present description, the same numbers refer to substantially the same elements, and may be described by quoting contents described in other drawings under such a rule, and the contents repeated or deemed apparent to those skilled in the art may be omitted.

1 and 2 are perspective views of the lower mold and the upper mold of the casting mold body according to one embodiment of the present invention, respectively.

Referring to FIG. 1, the lower mold 110 has a lower mold space 112 formed to correspond to a lower outer circumferential surface of a roller for a printer to be cast.

Four lower mold spaces 112 are provided so that four printer rollers can be cast at a time, and more than one can be formed.

In addition, lower shaft fixing grooves 113 connected to the lower mold space 112 are formed at both ends of the lower mold 110 in the longitudinal direction, respectively.

Referring to FIG. 2, the upper mold 120 has an upper mold space 122 formed to correspond to the upper outer circumferential surface of the roller for the printer to be cast, and the upper mold space 122 is the number of the lower mold spaces 112. 4 are provided in the same manner.

In addition, the upper mold 120 penetrates the upper mold 120 so as to be spatially connected to the upper mold space 122 to form a material injection hole 130. The material injection hole 130 is formed long in the length direction of the roller for the printer, and the width of the central portion 132 of the material injection hole 130 is wider than the width of the outer portion 134 of the material injection hole 130. It is.

In addition, upper shaft fixing grooves 123 connected to the upper mold space 122 are formed at both ends in the longitudinal direction of the upper mold 120, respectively.

As described above, after the lower mold 110 and the upper mold 120 are provided, as shown in FIG. 3, the roller shaft 10 used as the rotating shaft of the roller to be manufactured is mounted on the lower mold 110. It is disposed side by side with the lower mold space 112, wherein both ends of the roller shaft 10 is located in the lower shaft fixing groove 113 formed at both ends in the longitudinal direction of the lower mold 110, respectively. .

Thereafter, the upper mold 120 is covered and coupled to the lower mold 110 so that the upper mold space and the lower mold space face each other to form an inner space corresponding to the shape of the roller for the printer.

Figure 4 is a side view of the lower mold and the upper mold combined according to an embodiment of the present invention.

Referring to FIG. 4, the lower mold space 112 and the upper mold space 122 are coupled to each other so that the lower mold and the upper mold 110 and 120 are coupled to each other, and an inner space corresponding to the outer circumferential surface of the roller for a printer to be cast. 102 is formed.

At this time, the inner space 102 is formed to have a diameter slightly larger than the diameter of the printer-type roller to be finally produced, because the urethane material injected into the inner space 102 to be cured to a predetermined depth from the surface to be. This will be described later in more detail.

In addition, the lower mold 110 and the upper mold 120 is coupled to each other, the lower shaft fixing groove 113 and the upper shaft fixing groove 123 facing each other is disposed for the roller shaft ( Both ends of the 10) form a shaft fixing hole 140 is fixed.

The inner diameter S1 of the shaft 10 and the inner diameter S2 of the shaft fixing hole 140 may be provided in the same manner, but in this embodiment, the inner diameter of the shaft fixing hole 140 is larger than that of the roller shaft 10. To form a larger, surrounding the end of the roller shaft 10, the outer peripheral surface of the roller shaft 10 by using a fixing member 150 corresponding to the shaft fixing hole 140, the shaft fixing hole ( 140) to join.

As described above, by combining the lower and upper molds (110, 120), the roller shaft 10 is disposed across the inner space 102, both ends are coupled to the shaft fixing hole 140 The urethane material forming the roller for the printer is injected into the internal space 102 through the material injection hole 130.

In the process in which the urethane material is injected into the internal space 102 through the material injection hole 130, the urethane material may not flow evenly into the internal space 102 due to the viscosity of the urethane material, but may overflow to the outside. By injecting the urethane material through the central portion 132 of the material injection hole 130 is formed through the 120 having a wider width, the phenomenon that the urethane material overflows to the outside of the mold 100 can be prevented. have. For reference, the depth of the material injection hole 130 is preferably 5 ~ 15mm.

In addition, the urethane material is formed by forming a wider width than the outer portion 134 of only the central portion 132 into which the urethane material is to be injected among the material injection holes 130 formed in the longitudinal direction of the upper mold 120. While effectively injecting into the inner space 102, the volume of the material injection hole 130, which is injected into the urethane stock solution formed in the casting mold 100 at the time of casting can be effectively reduced, which can occur by grinding the protrusions formed thereby Minimize waste of material.

In addition, as described above, the volume of the material injection hole 130 is effectively reduced, thereby minimizing the size of the protruding portion formed thereby, and by the weight of the protruding portion in the process of polishing the portion after curing the urethane material. Eccentricity of the roller shaft 10, which may occur, may be minimized, thereby preventing bending of the roller shaft 10.

In addition, the length of the material injection hole 130 is preferably formed to be longer than the length of the roller for the printer to be produced, thereby forming longer than the length of the final roller to prevent at least a bubble (bubble) is generated in the roller formed body can do. After removing the cured urethane material from the casting mold 100, it is possible to cut both ends of the cured urethane material to match the length of the final product, it is possible to minimize the interference of the roller shaft 10 during the cutting. .

As described above, after the urethane material is injected into the internal space 102 through the material injection hole 130, the urethane material is cured by maintaining at a low temperature of 70 ~ 80 ℃.

As described above, after the urethane material is cured, a process of demolding the cured urethane material from the casting mold 100 may be performed.

At this time, the demolding process, as shown in Figure 5, the upper mold 120 is separated from the lower mold 110, the roller shaft 10 is moved through a moving means such as tongs, the cured urethane material ( 20 may be demolded from lower mold 110.

In addition, as shown in FIG. 6, the upper mold 120 is separated from the lower mold 110, and the urethane material 20 cured from the material injection hole 130 is removed from a predetermined tool such as a rod. By pushing through, the cured urethane material 20 may be demolded from the upper mold 120.

In this case, when the cured urethane material 20 is separated from the upper mold 120, there is no force applied to the roller shaft 10 by the weight of the cured urethane material 20, so that the roller shaft Deflection of (10) is prevented.

As described above, after demolding the cured urethane material 20 from the casting mold 100, the polishing process is performed, and the polishing process will be described below.

7 is a view showing a cured urethane material and a shaft for a roller cast by the casting method according to the present invention.

Referring to FIG. 7, the polishing process of removing the protruding portion 22 formed by the material injection hole 130 of the cured urethane material 20 may be removed by rotating the roller shaft 10 as the rotation axis. Can be.

However, since bending may occur in the roller shaft 10 by the protruding portion 22, as shown in FIG. 7, the diameter D1 of the roller to manufacture the protruding portion 22 is not affected. First, it is preferable to cut off at a predetermined height h1, and then rotate the roller shaft 10 as a rotation shaft to polish the polishing knife 30 as shown in FIG. 8.

In the process of cutting out the remaining protruding portion 22, it is possible to polish to the diameter (D1) of the roller to be manufactured, for this purpose, as described above with reference to Figure 4, the lower mold 110 and the upper mold ( The internal space 102 formed by 120 may be formed larger than the diameter D1 of the roller to be manufactured by forming a predetermined size larger than the diameter of the roller D1 for the printer to be cast.

The reason for forming a predetermined size larger than the diameter of the printer roller D1 to be cast is to improve the surface roughness of the cured urethane material 20 directly separated from the inner surface of the casting mold 100, and in fact, to protrude the portion ( This is because the eccentricity of the roller shaft 10 generated when polishing the remaining protruding portion 22 even when the height of the 22 is cut out by the predetermined height h1 is minimized.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

1 and 2 are perspective views of the lower mold and the upper mold of the casting mold body according to one embodiment of the present invention, respectively.

3 is a view in which a roller shaft is disposed in a lower mold.

Figure 4 is a side view of the lower mold and the upper mold combined according to an embodiment of the present invention.

5 and 6 are views for explaining the process of separating the cured urethane material from the lower and upper molds.

7 is a view showing a cured urethane material and a shaft for a roller cast by the casting method according to the present invention.

8 is a view for explaining a polishing process of the cured urethane material cast by the casting method according to the present invention.

<Description of the symbols for the main parts of the drawings>

10: roller shaft 20: cured urethane material

22: protrusion part 30: Polishing knife

100: casting mold body 102: internal space

112: lower mold space 113: lower shaft fixing groove

120: upper mold 122: upper mold space

123 ： upper shaft fixing groove 130 ： material injection hole

132: center portion 133: outer portion

140: shaft fixing hole 150: fixing member

Claims (25)

In the casting mold body for the casting of the roller for the printer manufactured through a low temperature reaction under atmospheric pressure, A lower mold having a lower mold space formed so as to correspond to a lower outer circumferential surface of the roller for the printer; And An upper mold space is formed to correspond to an upper outer circumferential surface of the roller for the printer, and is combined with the lower mold to face the upper mold space and the lower mold space, thereby forming an inner space corresponding to the shape of the roller for the printer. An upper mold having a material injection hole formed therethrough so as to be connected to the internal space; Casting mold body of the roller for a printer comprising a. The method of claim 1, Lower shaft fixing grooves connected to the lower mold space are formed at both ends of the lower mold in the longitudinal direction, respectively. At both ends of the upper mold in the longitudinal direction, upper shaft fixing grooves are formed to be connected to the upper mold space, respectively. The lower mold and the upper mold are coupled to each other so that the lower shaft fixing groove and the upper shaft fixing groove which face each other form a shaft fixing hole for fixing both ends of the roller shaft disposed across the inner space. Casting mold body of the roller for printer characterized by the above-mentioned. The method of claim 2, An inner diameter of the roller shaft and an inner diameter of the shaft fixing hole are the same. The method of claim 2, The inner diameter of the roller shaft is smaller than the inner diameter of the shaft fixing hole casting mold body of the roller for a printer. The method of claim 4, wherein A casting mold body of a roller for a printer, characterized in that it further comprises a fixing member surrounding an end of the roller shaft, the outer peripheral surface corresponding to the shaft fixing hole. The method of claim 1, The material injection hole is a casting mold body of a roller for a printer, characterized in that formed long in the longitudinal direction of the roller for the printer. The method of claim 6, The casting mold body of the roller for a printer, characterized in that the width of the central portion of the material injection hole is formed wider than the width of the outer portion of the material injection hole. The method of claim 6, The length of the material injection hole is at least longer than the length of the printer roller to be manufactured casting mold body of the roller for the printer. The method of claim 6, Casting material of the roller for the printer that the depth of the material injection hole is 5 ~ 15mm. In the casting method of the roller for a printer manufactured through a low temperature reaction under atmospheric pressure, A lower mold in which a lower mold space is formed to correspond to a lower outer surface of the roller for a printer, and a material injection hole formed to be connected to the upper mold space and the upper mold space so as to correspond to the upper outer surface of the printer roller. Providing an upper mold; Arranging a roller shaft on the lower mold side by side with the lower mold space; Combining the lower mold and the upper mold such that the upper mold space and the lower mold space face each other to form an inner space corresponding to the shape of the roller for the printer; Injecting a urethane material forming the roller for the printer into the inner space through the material injection hole; Curing the urethane material provided in the inner space; And Demolding the cured urethane material; Casting method of the roller for a printer comprising a. The method of claim 10, Lower shaft fixing grooves connected to the lower mold space are formed at both ends of the lower mold in the longitudinal direction, respectively. At both ends of the upper mold in the longitudinal direction, upper shaft fixing grooves are formed to be connected to the upper mold space, respectively. The lower mold and the upper mold are coupled to each other so that the lower shaft fixing groove and the upper shaft fixing groove which face each other form a shaft fixing hole for fixing both ends of the roller shaft disposed across the inner space. A method of casting a roller for a printer, characterized in that. The method of claim 11, A method of casting a roller for a printer, characterized in that the inner diameter of the roller shaft and the inner diameter of the shaft fixing hole are the same. The method of claim 11, The inner diameter of the roller shaft is less than the inner diameter of the shaft fixing hole casting method of the roller for a printer. The method of claim 13, Surrounding the end of the roller shaft, the outer peripheral surface of the roller casting method characterized in that it further comprises a fixing member characterized in that corresponding to the shaft fixing hole. The method of claim 10, The material injection hole is a casting method of the roller for a printer, characterized in that formed in the longitudinal direction of the printer roller. The method of claim 15, The width of the center portion of the material injection hole is formed wider than the width of the outer portion of the material injection hole. The method of claim 16, In the step of injecting the urethane material, Injection of the urethane material is a casting method of the roller for a printer, characterized in that the injection through the central portion of the material injection hole. The method of claim 10, In the step of curing the urethane material, The curing method is a casting method of the roller for a printer, characterized in that maintained for a predetermined time at 70 ~ 80 ℃. The method of claim 10, Demolding the cured urethane material, Separating the upper mold from the lower mold and moving the roller shaft to demold the cured urethane material from the lower mold. The method of claim 10, Demolding the cured urethane material, Separating the upper mold from the lower mold, And casting the cured urethane material from the material injection hole to demold the cured urethane material from the upper mold. The method of claim 10, After demolding the cured urethane material, Casting method of the roller for a printer, characterized in that for removing the protruding portion formed by the material injection hole of the cured urethane material. The method of claim 21, Method for removing the protruding portion formed by the material injection hole, And rotating the roller shaft to polish the cured urethane material to have a predetermined diameter. The method of claim 22, And after cutting the protruding portion to a predetermined height, the cured urethane material is polished to have a predetermined diameter while rotating the roller shaft. The method of claim 10, The length of the material injection hole is a casting method for a roller for a printer, characterized in that at least longer than the length of the roller for the printer to be manufactured. The method of claim 10, Casting method of the roller for the printer that the depth of the material injection hole is 5 ~ 15mm.

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