JP2005144810A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer equipped with a roll which is of a simple structure; low-priced; mass-productive; fast to an external force; and highly reliable in terms of paper feed properties. <P>SOLUTION: In the printer equipped with a paper feeder roll as a platen roll obtained by forcing a metal shaft with an irregularly worked outer shape into a cylindrical rubber tube with an irregular inside diameter so that the metal shaft can be fitted into the rubber tube, a specified amount of an adhesive is applied, at an equal interval, to the recessed part of a groove in the metal shaft and the metal shaft is integrated with the rubber tube. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a printer that prints on recording paper, receipt paper, ticket paper, and the like, and more particularly to a platen roll that is formed in a cylindrical shape and conveys an information recording medium.

  In recent years, thermal paper printers have become widespread in supermarkets, convenience stores and tollgate receipts. There is a strong demand from the market to realize a lightweight and low-cost printer while maintaining print quality. Among them, the rationalization and technical improvement of rubber parts are particularly desired in comparison with the remarkable technological progress of electronic parts and printing components.

  As this type of platen roll material, for example, those using silicone rubber, EPDM rubber or chloroprene rubber are known.

  However, in the conventional platen roll manufacturing method, a rubber material mixed with a curing agent is press-fitted into a metal mold provided with a metal shaft and cured by heating. After the demolding, secondary heating is performed as necessary. Furthermore, the roll surface is polished with a grindstone rotating at high speed with a polishing machine to correct the eccentricity and form the surface. The complexity of the process and the expensive processing machine are necessary, which is a cause of cost increase. In recent years, there has been a demand for a simple manufacturing method and lead time for overseas production, and a short delivery time for shortening mass production.

  On the other hand, there is a proposal for an elastomer injection molding method as a low-priced platen roll. NBR rubber, urethane rubber, etc., are considered to have an effect of lowering the unit price of parts, but there are no varieties having a hardness of 50 degrees or less. Furthermore, in a thermal printer that considers the printer operating temperature range from -10 degrees Celsius to 70 degrees Celsius, the elastomer has a large change in hardness when heated, and is difficult to use as a roll material.

  In addition, a proposal has been made to press-fit a tubular rubber into a metal shaft. However, when pressure is partially applied to the platen roll with a finger or the like, a part of the periphery of the pressed rubber tube moves in the axial direction, and a concave shape is partially generated. Although the deformation recovers with time, the print quality during that time causes a thin print defect due to insufficient pressing force.

  That is, it is desirable to provide an inexpensive thermal platen roll while ensuring quality for various hard usage applications of the user. In addition, there is a demand for technical proposals that can be produced overseas and are not expensive equipment or manufacturing in complicated and inferior environments.

JP 58-139409 A JP 59-049956 A JP 63-163020 A Japanese Patent Laid-Open No. 01-1000029 Japanese Patent Laid-Open No. 03-195647

    1) High reliability: Even if an external force is directly applied to the platen roll, a stable outer diameter and eccentricity can be maintained and good print quality can be stably provided. For example, in the case of a trouble such as a paper jam, forcible pressure is applied to the platen roll. Also, the platen roll may be pry open with a finger or a nib. Therefore, even if the platen roll as a component is partially pressed strongly, it is necessary to manufacture the component firmly. It is the responsibility of the printer to operate normally even in a user environment that is not initially envisioned.

    2) Quality stability: It is natural to maintain the current printing quality and provide stable printer operation.

    3) Low price: By adopting a manufacturing process that allows continuous production without using expensive machines, the quality is stable and the component configuration can be reexamined drastically, which can be offered to consumers at a low price.

  The present invention has been made to solve such a conventional technical problem, and includes a platen roll realized by a simple manufacturing method that is inexpensive, has high quality and accuracy, and does not use an expensive apparatus. An object is to provide a printer.

  The present invention proposes the following means to solve the above problems.

  In order to solve the above-described problems, the present invention provides a printer having a paper feed roll that is a platen roll that is press-fitted with a metal shaft whose outer shape is processed into a different shape so as to fit into a cylindrical rubber tube having a different inner diameter. The adhesive is applied to the concave portion of the groove of the metal shaft at regular intervals, and then integrated with the rubber tube. With the above-described configuration, the roll can be completed by simply press-fitting the shaft into a rubber tube that can be simultaneously vulcanized by extrusion, and the shape can be stabilized with an adhesive against external force during use. For high-torque paper feed requests, the function is sufficient with the tightening force due to the difference in the shape of the irregularly fitted shaft outer diameter and tube inner diameter.

  Further, one or more locations of the fitting are present on the circumference of the metal shaft. With the above configuration, it is effective to fit a physical uneven portion to a roll that requires high torque or a roll that uses low hardness rubber.

  The adhesive may be applied at two or more locations on the metal shaft. With the above-described configuration, an excessive amount of adhesive can be absorbed in the groove, and the adhesive can be prevented from protruding to the contact surface with the rubber tube that affects eccentricity. In addition, by interspersed, air can enter and exit the moisture-absorbing and curable adhesive present inside the rubber tube, and curing is promoted over time.

  Further, the rubber tube is formed by extrusion molding. With the above configuration, a rubber tube having a uniform shape can be provided at a low cost.

  Further, the metal shaft is drawn or pressed. With the above configuration, an inexpensive and stable quality shaft production process can be utilized and a good printer can be provided.

  Further, the discharge amount of the adhesive is 60% or less of the volume formed by the width and depth of the groove. With the above configuration, it is possible to prevent the adhesive from protruding and to allow air to enter and pass through.

  The adhesive is a moisture curable adhesive. With the above configuration, the assembly insertion property is simplified, and an addition-type curable composition having strong adhesion to the silicone tube can be used.

  The adhesive has a viscosity of 1 Sto to 100,000 Sto. With the above configuration, the adhesive can be stably applied to the groove in a small amount. It is also possible to control the insertion resistance force when assembling the rubber tube.

  In addition, an adhesion auxiliary material such as a primer is applied to the concavo-convex portion on the outer periphery of the metal shaft. With the above structure, the strength can be increased with respect to the silicone rubber having a weak adhesion.

  Further, the fitting height of the rubber tube is 2% to 30% of the rubber wall thickness. Since the influence of the hardness change by the uneven | corrugated shape of a base | substrate is eased as a platen roll by the said structure, since a uniform deformation amount is maintained, such as a thermal printer, it is especially effective in a platen roll.

  Further, the fitting portion of the metal shaft is a convex portion and the rubber tube fitting portion is a concave portion, or the fitting portion of the metal shaft is a concave portion and the rubber tube portion is a convex portion. To do. With the above configuration, the shape and directionality of the mating portion can be realized without any restriction.

  The rubber tube has a rubber hardness of 60 degrees (JIS-A) or less. With the above-described configuration, a good printing range spreads with the low hardness rubber of the roll described above, leading to stable quality.

  Further, the rubber tube is made of silicone rubber. With the above configuration, it is possible to make use of a material having a characteristic that is less in compression set and insensitive to temperature change in improving print quality. That is, there is little change in rubber elasticity from a low temperature to a high temperature at which the thermal head generates heat, and the deformation of the roll can be reduced even when the thermal head is constantly in pressure contact.

  Further, the corners of the concavo-convex portion on the outer periphery of the metal shaft are set from R0.05 mm to R1 mm. With the above configuration, even when a high torque is applied, the low hardness rubber material can exert an effect of preventing the occurrence of deviation or peeling from the rubber shaft.

  As described above, according to the present invention, it is possible to obtain a low-priced and high-quality platen roll that can be smoothly mounted on a metal shaft with a simple configuration.

That means
1) Conventionally, an organic solvent-based solvent was applied to a metal shaft and rubber adhesive and dried, which had some influence on the factory periphery. This time, safety has been improved without using organic solvents or other substances that affect the environment.

2) As a merit of bonding the rubber tube to the metal shaft, a highly reliable printer can be provided even when the user is used hard.

3) While making use of the characteristics of non-adhesive silicone rubber, the concave and convex shape is physically made difficult to come out with respect to the rotation direction of the platen roll, and is joined to the metal shaft.

4) As a method of fixing the silicone tube to the metal shaft with an adhesive, application of adhesion without eccentricity becomes a problem. This proposal is filled with a hygroscopic adhesive in the gap (playing part) of the pulling shaft uneven part, and the eccentricity that affects the paper feeding function is 0.1mm or less (current polishing is 0.05mm or less) ).

5) By recessing the metal shaft, the continuously formed metal shaft can be used while being supported by a cylindrical guide without any additional processing. This is a technical proposal with a simple structure and improved design flexibility.

6) Silicone material is effective in reducing the hardness, which is a factor that improves paper feeding performance, but by setting multiple fitting parts with few steps in the outer circumferential direction of the metal shaft, partial hardness unevenness due to low hardness The torque is improved while eliminating the problem. Low eccentricity and fluctuations in rubber thickness contribute to stable quality and low price.

7) The polishing process can be omitted, and the platen roll shaft can be formed by a method in which the material and construction method are inexpensive while maintaining the platen roll quality such as process time reduction, cost reduction, omission of management items.
As a result, the conventional wasteful process was omitted, and the cost reduction of the roll, which had been a major issue in realizing a low-priced and high-quality printer, was resolved, making a dramatic progress. Such a printer of the present invention employs extrusion processing of a deformed metal shaft and silicone tube rubber, and is produced at low cost with high quality and completed with a unique fitting process to complete a roll with high accuracy and low cost. Platen rolls can be obtained. In other words, it is possible to obtain a good platen roll that is mass-productive and smooth against high-torque paper feeding.

  In addition, a high-reliability printer that can be used in a hard working environment has been realized by amortizing high mold costs, which has been a problem in the process of manufacturing rubber platen rolls. Functionally, it is considered one of the key technologies, such as characterizing product strategies in line with the trend of small size, light weight, and improving portability, and expanding the range of design freedom. I think it is an important proposal in the field of consumer electronics and consumer products.

  Hereinafter, the effectiveness will be described in detail through examples of the present invention.

FIG. 1 is a cross-sectional view of a platen roll 6 of the printer of the present invention.
An adhesive 3 was applied to a metal shaft 2 extruded into a deformed shape with an outer diameter of a concave shape 4 in a tubular rubber tube 1 extruded with a deformed inner surface, and then pressed to form a platen roll 6. The concave portion 4 of the metal shaft 2 engages with the rubber tube convex portion. Basically, the outer dimensions of the metal shaft 2 and the inner diameter of the rubber tube coincide with each other. However, by reducing the inner diameter of the rubber tube 1, the size of the engagement is stabilized and slippage is lost when rotational torque is applied. There is an effect to become difficult. However, when the outer shape of the metal shaft 2 is large, the transportability of paper feeding is stabilized when a large torque is applied after the engagement, but the fitting workability at the time of press-fitting becomes difficult. In particular, when there are a plurality of engagement points, the viscosity of the adhesive 3 loaded in the concave portion further makes assembly workability difficult. In this example, four contract locations were used for the description, but the present invention is not limited to this embodiment, and multiple contracts are desirable.

  On the other hand, if the outer shape of the metal shaft 2 is small, there may be a problem that when a large torque is applied after fitting, the metal shaft 2 is easily deformed and peeled off. In particular, when the rubber hardness of the rubber tube 1 is low and the wall thickness is thin, the aforementioned tendency is likely to occur. In this embodiment, the outer diameter of the metal shaft 2 is 4 mm, the inner diameter of the rubber tube 1 is 3.9 mm, and the outer diameter is 8 mm. The convex shape of the rubber tube 1 was 0.8 mm wide and 0.45 mm deep, and the concave shape of the metal shaft 2 was 1.0 mm wide and 0.5 mm deep. The height (shape) of the convex part of the rubber tube 1 is 1% to 50%, preferably 2% to 10%, with respect to the outer diameter of the metal shaft 2. If the shape is large, the hardness of the rubber affects the hardness of the underlying metal shaft 2 and induces paper feed failure. On the other hand, when the shape is small, when the platen roll 6 is deformed, there is a problem that the platen roll 6 is detached and rotates. In general, 2 to 5 places are often used at equal intervals. The width and height of the concavo-convex shape vary depending on the outer dimensions of the metal shaft 2 and the thickness and hardness of the platen roll 6, but about 10% is preferable for the thickness. That is, since the deviation of the platen roll 6 from the paper feed torque of the printing paper 7 does not occur with the metal shaft 2, there is an effect of stabilizing the change in the shape of the uneven part.

  Moreover, although the corner of the uneven | corrugated | grooved part of the outer periphery of the metal shaft 2 was made into R1 mm from R0.05mm, when a corner angle (R) is large, the slipping torque of an engagement location will become weak and the effect of uneven | corrugated shape will decrease. From the processing accuracy of the drawing shaft and the industrial accuracy of the extruded rubber tube, 0.05 mm to 1 mm is considered effective.

  The eccentricity and outer diameter accuracy, which are the lifelines of the platen roll 6, are as good as the current state (Example 2) with the accuracy that can be realized by the existing practical and technical extrusion. That is, the eccentric accuracy of the platen roll 6 affects the extrusion dimension accuracy, and the outer shape accuracy depends on the extrusion conditions. The normal extrusion accuracy is eccentric and plus or minus 0.15 micrometer is industrially realized. In terms of external accuracy, tube rubber of plus or minus 0.1 micrometer can be purchased in the market.

  FIG. 2 is a perspective view of the printer of the present invention that feeds the printing paper 7. The printing paper 7 is supplied from the upper right of the figure, and is printed while being pushed by the thermal head 5 against the platen roll 6 while being guided by a paper guide. The driving force of the motor 8 is transmitted by the gear 9, and the printing paper 7 is conveyed and discharged upward in the figure. Although not visible in the figure, the coloring surface of the printing paper 7 comes into contact with the thermal head 5 and is pressed by the platen roll 6. The thermal head 5 generates heat and prints by a print signal activated by the power switch. The printing paper 7 is controlled by a platen roll 6 having both a paper feed function and a platen function. The applied pressure is transmitted to the outer periphery of the roll, and a part of the platen roll 6 is deformed and conveyed by the frictional resistance with the printing paper 7.

  Further, since the thermal head 5 generates a temperature of 70 degrees or more at the time of color development, the platen roll 6 receives a temperature of about 50 degrees or more via the printing paper 7. This is a necessary condition for the platen roll 6 to be required to have a high compression set, a low temperature dependency, and a low hardness. Silicone rubber meets the above conditions and is widely used in thermal printers. However, since the contact angle is as large as 110 degrees or more, there is a problem that it is difficult to adhere to other substances. When a combination shaft of the concentric metal shaft 2 and the platen roll 6 was used, torque was applied between the metal shaft 2 and the platen roll 6 when the printing paper 7 was transported, resulting in shaft slip failure. However, this technical problem is suppressed by adopting a physical concave / convex shape engagement by a combination of a rubber tube 1 and a metal shaft 2 which are deformed and extruded. Both the platen roll 6 and the metal shaft 2 are formed in a stable shape, and are realized at low cost by adopting an extrusion molding process.

  In FIG. 1, the moisture-absorbing curable adhesive 3 absorbs moisture from the moment it is taken out of the container and touched the atmosphere, and curing begins. Since the curing gradually accelerates from the surface toward the inside and the viscosity increases, a small amount of the adhesive 3 applied to the concave portion of the metal shaft 2 can be smoothly inserted unless it contacts the rubber tube 1 while the viscosity is low. I can't work. When the viscosity of the adhesive 3 further increases, the rubber tube 1 has internal stress generated during the insertion process with the metal shaft 2, leading to an increase in eccentricity. As a result, it becomes one of the causes of printing failure of the platen roll 6.

  In an environment where the room temperature is 20 degrees and the humidity is 65%, the assembly of the rubber tube 1 must be completed within 3 to 10 minutes after application of the moisture-absorption-type adhesive 3. Preferably, about 5 to 7 minutes can be performed with an insertion pressure of 2 kgf / cm 2 and a stress reduced as much as possible. Of course, a shorter assembly time is required in summer, such as 30 degrees Celsius and 80% humidity.

  In FIG. 3, the application amount of the adhesive 3 is preferably 60% or less of the space between the metal shaft 2 and the rubber tube, and preferably 5% to 30%. If it is 5% or less, the adhesive 3 has a small contact area with both members, cannot exhibit sufficient strength, and it is difficult to apply a small amount. Further, if it is 30% or more, the above-mentioned obstacle to air circulation may occur.

  The reason is that the adhesive 3 applied to the central portion of the metal shaft 2 in the longitudinal direction has a problem that after being covered with a rubber tube, the air does not enter and exit, moisture is blocked, and curing is not accelerated. Therefore, in order to allow the air to enter and exit even after insertion and assembly, it is necessary to provide a certain space in the space formed by the concave portion of the metal shaft 2 and the convex portion of the rubber tube even after the adhesive 3 is applied. The dispenser was set at 2 atm for 0.3 seconds as the adhesive and discharge conditions, and 0.003 g to 0.01 g of adhesive could be discharged intermittently stably.

  Wipe off moisture, oil, and dirt in advance on the surface to be bonded.

  It is also effective to make the adhesive 3 interspersed with the concave portions of the metal shaft 2. The inventor used a dispenser as a method for stably supplying the adhesive 3 in a small amount. In this dispenser, it is difficult to stably discharge a liquid having a viscosity of 5000 Sto or more stably in a minute amount. Therefore, as shown in FIG. 3, a certain amount of the adhesive 3 is poured into the groove of the concave portion of the metal shaft 2 in order to be stabilized. Therefore, the nozzle at the tip of the dispenser was moved quickly along the groove, and the discharge signal was intermittently turned ON and OFF, thereby being scattered.

  The shapes of the 13 cross section and the 14 cross section are shown in FIG. The 13th section is a case where the adhesive 3 is filled, and the 14th section is a state where a space which is not filled is formed.

  The reason for forming these two states is that, as shown in FIG. 4, the convex portion on the inner surface of the rubber tube is incorporated by scraping the adhesive 3 applied to the concave portion of the metal shaft 2, so that a partial groove It protrudes to the point where the metal shaft 2 and the rubber tube are in direct contact with each other, which may cause eccentricity.

  As a countermeasure for this, the above-described dotted application of the adhesive 3 is proposed. That is, the excess adhesive 3 that has been scraped off by the convex portions on the inner surface of the rubber tube can be absorbed in the spaces formed by the dots.

  If the adhesive 3 is excessively discharged to the concave portion of the metal shaft 2 as shown in FIG. 5, a part of the adhesive 3 protrudes when the metal shaft 2 is assembled, and the eccentricity of the platen roll 6 is increased. The dispenser used for applying the adhesive 3 can control the discharge amount by the pressure of the compressed air, the discharge time, and the hole diameter at the tip of the nozzle depending on the accuracy of the manufacturer and equipment. Furthermore, since it is scattered, the adhesive 3 can form a good shape for eccentricity in a slender stringing state along the groove according to the moving speed of the nozzle tip.

  That is, if the adhesive 3 is uniformly discharged into the concave portion of the metal shaft 2, the possibility of occurrence of eccentricity failure as shown in FIG. 5 increases. It was shown that the cause of occurrence of the eccentric rubber tube 10 was the protruding adhesive 3.

  As the adhesive 3, a hygroscopic curable adhesive 3 was used. If an adhesive 3 having high adhesion between the metal shaft 2 and the rubber tube 1, particularly silicone rubber, is selected, it can be obtained in the market. Silicone rubber, epoxy, urethane, polyether and modified products thereof are used for the base material of the adhesive 3. In addition, emulsion, hot melt, and polyolefin adhesive 3 are also effective.

  Examples of the adhesion assistant include commercially available primer C, primer D, primer G, primer T, primer MT and organic solvents (toluene, xylene, isopropyl alcohol, butanol, ketone, ester).

  The rubber hardness of the rubber tube 1 can be 80 to 10 degrees (JIS-A standard), and preferably the hardness is 30 to 50. The lower the hardness, the lower the wear resistance, and the higher the hardness, the smaller the nip value (the length of the platen roll 6 being crushed by pressurization), which narrows the good printing range. The deformation due to the eccentricity or the pulsation of the rubber tube 1 is eliminated as the hardness decreases, and is particularly effective when the rubber hardness is 40 degrees or less.

  Silicone rubber used in extrusion molding can be easily selected by actual tests. Specific examples include silicone adhesives, silicone potting materials, silicone gel products, silicone resins, silicone surface protective coating agents, fluoro For example, silicone rubber. The addition reaction type or the condensation reaction type may be used. Silicone rubber can be used alone or in combination of two or more. In other words, for flame retardancy, non-fluidity, thixotropy, heat dissipation, heat resistance, conductivity, solvent resistance, cold resistance, adhesiveness, high strength, electrical contact failure countermeasures, etc. Additives may be added.

  Furthermore, instead of the silicone rubber used, it can be used equally if the following rubber is selected appropriately. That is, natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene- (diene) -rubber (EPM or EPDM), chloroprene rubber (CR) Isobutene-isoprene rubber (IIR), isoprene rubber (IR), acrylic rubber (ACM), ethylene-acrylic rubber, and the like can be considered. Also, an appropriate mixture of these various rubbers may be used.

  Furthermore, in addition to the filler, additives such as conductive material additives, pigments, deterioration inhibitors, stabilizers, and function-imparting agents may be blended. The composition includes a plasticizer, a crosslinking agent, a vulcanization accelerator, a vulcanization accelerator, a kneading accelerator, an activator, and an antiaging agent as long as the mechanical strength and processability specified above are not deteriorated. , Ozone degradation inhibitor, ultraviolet absorber, light stabilizer, tackifier, rubber softener, rubber reinforcing agent, filler, reinforcing agent, foaming agent, foaming aid, internal mold release agent, lubricant, mold release agent, Add known rubber additives such as slip agent, anti-fogging agent, flame retardant, antistatic agent, modifier, antioxidant, heat stabilizer colorant, scorch inhibitor, coupling agent, preservative, antifungal agent May be.

  Examples of the conductive additive include carbon black, graphite, particulate Ag, particulate Au, particulate Ni, particulate stainless steel, particulate titanium oxide, tin oxide, particulate conductive zinc white, AU-AG, and Ni-Ag. Examples include composite, silver-coated glass beads, and particulate carbon balloons.

Further, as the rubber additive, various fillers typified by thermoplastic resin, thermosetting resin, glass fiber, carbon fiber, carbon black, and the like may be added.
In addition to SUM, SUS, aluminum alloy steel wire, etc., high rigidity plastics such as polyphenylene sulfide (PPS), polyether ether ketone (PEEK), liquid crystal polymer (PLA), and polysulfone (PSU) are used for the shaft material. It is possible to achieve automation and cost reduction through weight reduction and continuous production.

  As a result, the paper feed was normal even after printing 10 million lines on the printing paper 7, and there was no problem in printing. Further, even when the platen roll 6 built in the printer was strongly pressed directly with a finger, the concave deformation of the platen roll 6 due to the displacement of the rubber tube did not occur. The pressure on the platen roll 6 of the thermal head 5 was uniform, and no occurrence of printing shading was observed. It was understood that the reason was that the rubber tube was in close contact with the metal shaft 2 and exhibited a resistance against external stress. Even after the printing durability test of the printing paper 7, peeling between the outer peripheral portion of the metal shaft 2 and the inner surface of the silicone tube was not observed, and the clear printing did not change until the end. As shown in FIG. 8, there was no difference in quality from the conventional platen roll 6, and there was no particular problem.

  The roll price of the silicone tube was about ½ compared to the conventional vulcanization method. The price difference of the rubber itself was large due to the mass productivity of the manufacturing method and the price of individual molds. As a result, the high quality and low cost of the platen roll 6 of the present invention were demonstrated. Details are shown in FIG.

(Conventional example 1)
It is sectional drawing of the platen roll 6 of the same structure as this invention which has not adhere | attached the conventional example like FIG.

  As shown in FIG. 6, in the rubber tube 1 of the conventional example, when an external force is applied by a finger, the pressed portion is recessed, and a part of the rubber tube moves along the groove of the extraction shaft. Even with silicone rubber having a small compression set, a part of the printing paper 7 becomes white as shown in FIG. It is understood that the pressure of the deformed thermal head 5 due to the printing is weakened on the printing paper 7 and a white and non-colored portion 11 is developed.

  As a result, even after 10 million lines were printed on the printing paper 7, the paper feed was normal and printing was no problem. The mottled printed portion 11 was finally solved, but during that time, defects continued to occur and became a quality problem. Details are summarized in FIG.

(Conventional example 2)
FIG. 8 is a cross-sectional view of a platen roll 6 having a compression-molded structure according to a conventional example.

  As shown in FIG. 8, the platen roll 6 of the conventional example is coated with the primer 12 on the entire surface of the metal shaft 2 made of SUM that comes into contact with the silicone rubber 1 and dried at 60 degrees for 30 minutes. Although not shown, the metal shaft 2 treated with the primer 12 is placed on a rubber mold heated at 175 ° C. while adjusting a jig at the center of the mold, and the upper mold is covered. An appropriate amount of the unvulcanized silicone rubber product is weighed and injected into a compression molding machine provided with the mold and vulcanized. Although the mold is large because the platen roll 6 is formed, high precision is required for eccentricity. The primary vulcanization condition was 13 minutes at 175 degrees, and the silicone rubber was temporarily cured. The platen roll 6 is taken out from the mold, put into a high-temperature tank, and the platen roll 6 is treated and completely cured under secondary vulcanization conditions at 200 degrees for 4 hours. Scattering of by-products generated from the unvulcanized reaction, removal of volatile components in the compound, and stabilization of physical properties of compression set were achieved.

  Next, the outer peripheral side surface of the platen roll 6 was subjected to outer diameter processing with an expensive polishing machine using a disc-shaped grindstone at a peripheral speed of 1800 rpm. A predetermined eccentricity accuracy was ensured in this step. The surface roughness of the outer periphery after polishing was measured to be 6 microns with Ry, and formed a substantially uniform surface. Although dust generated in the polishing process is collected, it causes the working environment to deteriorate.

  As a result, even after 10 million lines were printed on the printing paper 7, the paper feed was normal and printing was no problem. The clear print did not change until the end, and there was no problem. Details are summarized in FIG.

  However, expensive processes such as rubber molds, rubber kneaders, compression molding machines, polishing machines and dryers are used, and many processes and time are spent. Therefore, the number of management items increases, and a large number of workers are required, which inevitably increases costs. In addition, the organic solvent-based primer treatment operation has a considerable adverse effect on the human body, which leads to one of the factors such as wastewater treatment and air pollution. Furthermore, the work of the rubber kneader for several hours involves the work of turning the rotating rubber by hand, and is a dangerous work in conjunction with the machine.

1) Suitable for printer paper feed rolls.
Example: Paper feed roll for impact printer Example: Paper feed roll for inkjet printer Example: Paper feed roll for electrophotographic printer

2) Suitable for the field of fixing a compact silicone tube to the shaft.
Example: Fixing the rubber part of the pen that touches the hand Example: Fixing the handle with a silicone tube inserted

3) Suitable for the field that regulates shaft rotation.
Example: Car handle cover, etc. Example: Train and bus straps, etc. Example: Rubber covers for bathrooms and handrails on stairs, etc.

It is sectional drawing which shows the position of the rubber tube 1, the metal shaft 2, and the adhesive agent 3 of this invention of Example 1. FIG. 1 is a perspective view of a printer of the present invention shown in Embodiment 1. FIG. 1 is a perspective view of a metal shaft 2 applied with an adhesive of Example 1. FIG. 2 is a cross-sectional view of a metal shaft 2 applied with an adhesive of Example 1. FIG. It is sectional drawing which the adhesive agent protruded and the rubber tube deform | transformed. 6 is a cross-sectional view of a rubber tube 1 deformed by an external force of Comparative Example 2. FIG. It is sectional drawing of the rubber tube and metal shaft 2 which do not apply | coat the adhesive agent of the prior art example 1. FIG. It is sectional drawing of the platen roll of the compression molding of the prior art example 2. 6 is a comparative diagram of print samples of Example 1 and Comparative Example 1. FIG. It is the figure which put together the result of Example 1 and the comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rubber tube 2 Metal shaft 3 Hygroscopic hardening type adhesive 4 Recessed part 5 Thermal head 6 Platen roll 7 Printing paper 8 Motor 9 Gear 10 Eccentric platen roll part 11 White spot defective part 12 Conventional metal shaft primer 13 Adhesive application Cross section 14 Cross section without adhesive

Claims (14)

  In a printer having a paper feed roll that is press-fitted with a metal shaft whose outer shape is processed into a different shape so as to fit into a cylindrical rubber tube having a different inner diameter, the adhesive is used as a recess in the groove of the metal shaft. A printer which is integrated with the rubber tube after a predetermined amount is applied at regular intervals.   The printer according to claim 1, wherein at least one fitting portion exists on a circumference of the metal shaft.   The printer according to claim 1, wherein the adhesive is applied at two or more locations on the metal shaft.   The printer according to claim 1, wherein the rubber tube is formed by extrusion molding.   The printer according to claim 1, wherein the metal shaft is drawn or pressed.   6. The printer according to claim 1, wherein the discharge amount of the adhesive is 60% or less of the volume formed by the width and depth of the groove.   The printer according to claim 1, wherein the adhesive is a moisture curable adhesive.   8. The printer according to claim 1, wherein the adhesive has a viscosity of 1 Stokes (hereinafter referred to as Sto) to 100,000 Sto.   The printer according to any one of claims 1 to 8, wherein an adhesion auxiliary material such as a primer is applied to the uneven portion on the outer periphery of the metal shaft.   10. The printer according to claim 1, wherein the fitting height of the rubber tube is 2% (hereinafter referred to as%) to 30% of the rubber wall thickness.   The fitting portion of the metal shaft is a convex portion and the fitting portion of the rubber tube is a concave portion, or the fitting portion of the metal shaft is a concave portion and the rubber tube portion is a convex portion. Item 11. The printer according to any one of Items 1 to 10.   The printer according to claim 1, wherein the rubber tube has a rubber hardness of 60 degrees (JIS-A) or less.   The printer according to claim 1, wherein the rubber tube is made of silicone rubber. The printer according to any one of claims 1 to 13, wherein a corner of an uneven portion on an outer periphery of the metal shaft is set to R0.05 mm to R1 mm.

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