CN106827901A - The temperature control erasing apparatus that the easy stump that rubs is used - Google Patents

Abstract

The temperature-controlled erasing device used by the rubbing and erasable pen relates to the field of decolorization of heat-sensitive ink, especially the erasing of handwriting of the rubbing and erasable pen used by students. In order to avoid damage to the paper, the technical solution is: the temperature-controlled erasing device used by the friction pen, which is characterized in that: a power supply is connected in series with two switches, one is a temperature-controlled switch, which is a normally closed switch, and the other is a power switch. It is a normally open switch, usually in the off state; the temperature control switch is composed of a heating resistor and a bimetal, the heating resistor generates heat when the power is turned on, and the bimetal disconnects the circuit when it reaches the designed temperature. The design temperature is 55‑70 degrees Celsius. The beneficial effects are: there is no need to rub the surface of the paper, and the paper will not be damaged; the use of erasers is reduced, saving social resources; The economical use of the device is low in cost, easy to manufacture, convenient to use and easy to use.

Description

Temperature-controlled erasing device for friction-erase pens

technical field

The invention relates to the field of decolorization of heat-sensitive ink, in particular to the aspect of erasing handwriting of rubbing and easy-erasing pens used by students.

Background technique

Now the rubbing pen uses heat-sensitive ink, and its writing will disappear when the temperature is relatively high. Elementary school students like to use rubbing pens for writing in order to keep the roll surface or the surface of homework paper clean. When they need to modify, they usually use an eraser to reach a higher temperature through friction to make the handwriting disappear. The problem that exists is: fast friction can cause the temperature to rise quickly, and fast friction can easily cause paper damage.

Contents of the invention

In order to avoid damage to the paper, the present invention designs a temperature-controlled erasing device for a friction-erasable pen.

The technical solution adopted by the present invention to achieve the purpose of the invention is: a temperature-controlled erasing device used by the friction-easy-erase pen, which is characterized in that: a power supply is connected in series with two switches, and one switch is a temperature control switch, referred to as a temperature control switch. The switch is a normally closed switch, usually in the connected state, the other switch is the power connection switch, referred to as the power switch, the power switch is a normally open switch, usually in the disconnected state; the temperature control switch is composed of a heating resistor and a bimetal , The heating resistance sheet generates heat when the power is turned on, and the bimetal sheet disconnects the circuit when it reaches the designed temperature. The designed temperature is 55-70 degrees Celsius.

The outer casing of the temperature control erasing device is composed of two sleeves, which are called the upper sleeve and the lower sleeve for the convenience of expression. The upper sleeve and the lower sleeve are connected by elastic parts (metal springs or elastic plastics or springs) on the inside. There is a ring of metal sheet on the outside of the upper sleeve as a contact of the power switch, and the upper end of the outer sleeve of the lower sleeve is another contact of the power switch. Press down on the upper sleeve Compress the elastic member to make the contact on the outer side of the upper sleeve contact with the contact on the outer side of the lower sleeve, and turn on the power switch (after removing the external force, the elastic member separates the upper sleeve from the lower sleeve, and turns off the power switch).

The heating resistance sheet of the temperature control switch is a thin sheet with a thickness of 0.1-0.2 micron and an area of 0.5-1 square centimeter.

The heating resistance sheet is fixed on the outer side of the inner upper end of the upper sleeve, the outer surface of the heating resistance sheet is 3-5mm away from the port of the upper sleeve, and the port of the upper sleeve is covered with a layer of grid.

The power supply is a dry battery or a rechargeable battery, that is, the voltage is about 1.5 volts, and the current can reach 1 ampere. It is located in the hollow space formed by the inner side of the upper sleeve and the lower sleeve.

The upper sleeve and the lower sleeve form a pen cap, the lower end of the pen cap is threaded, and the pen cap can be threadedly connected to the upper end of the rubbing pen.

There is a layer of non-conductive ceramic sheets on both sides of the heating resistance sheet (ceramic sheets are poor conductors, that is, non-conductive, which is the prior art), the thickness of the ceramic sheets is 0.5-1 mm, and the center of the inner ceramic sheets has A circular hole (circular through hole) with a diameter of 2-3 mm is used for one end of the bimetal (electrode) to contact the heating resistor.

The outer edges of the two layers of ceramic sheets have annular grooves with a width of 1 mm and a thickness of 0.05 mm. The two grooves face each other to form a circular space with a width of 1 mm and a thickness of 0.1 mm. The circular space is arranged A ring of copper material as an electrode contacts the edge of the heating resistor.

The circumference of the upper end surface of the upper sleeve is fixed with balls. The rolling friction of the ball is small and the movement is smooth, which can reduce the contact friction between the end surface of the device and the paper. Rolling is a prior art and can be realized.

The beneficial effects of the present invention are: the most important advantage is that there is no need to rub the surface of the paper, so the paper will not be damaged; It can be used alone or it can be attached to the rubbing pen to become a part of the rubbing pen, such as the pen cap. The position of the cap of the existing rubbing pen is an eraser, and the device for pressing the refill is on the side, so the existing The upper end of the friction pen can be threaded, so that the device can be connected with the friction pen through the thread, because it can be disassembled, so it is not necessary to equip each pen with this device, which can achieve the economical use of this device; the cost is low , easy to make, easy to use, easy to use; short heating time, tolerable; less heat storage, will not burn the skin.

Description of drawings

Figure 1 is a schematic diagram of the circuit; Figure 2 is a schematic diagram of a temperature control switch; Figure 3 is an overall schematic diagram of the device; Figure 4 is a schematic diagram of circuit connections;

Among them, 1. Power supply; 2. Temperature control switch; 3. Power switch; 4. Heating resistor; 5. Bimetallic sheet; 6. Upper sleeve; 7. Lower sleeve; 8. Elastic member; .

detailed description

As the formulation of heat-sensitive ink changes, its color development and decolorization temperature will also change. The following are the parameters of a heat-sensitive ink found on the Internet: the ink is colored at room temperature, it is heated to 50°C-60°C to lose color, and cooled to minus 5°C-minus 20°C to develop color, and it is reversible. Specifically, the starting decolorization temperature is about 45°C, and the complete decolorization temperature is about 55°C. The starting color temperature is about minus 5°C, and the full color temperature is about minus 20°C. The average fineness of the microcapsules in the ink is 2-3 microns.

The temperature-controlled erasing device used by the rubbing pen includes a power supply 1 and two switches. The power supply 1 and the two switches are connected in series. For the convenience of distinguishing the two switches, one switch is a temperature control switch, referred to as the temperature control switch 2. A switch is a power connection switch, referred to as the power switch 3, which is a conventional circuit control switch and is a prior art for connecting the power supply; the temperature control switch is the main component of the present invention. 5 components, the heating resistance sheet 4, because of its large resistance value, generates heat when the power is turned on to increase the temperature, and the bimetal sheet disconnects the circuit when it reaches the designed temperature. According to the parameters of the existing heat-sensitive ink, the design temperature is 55-70 degrees Celsius which is more appropriate. According to the physiological limit of the human body's tolerance to high temperature, there is a risk of burning the human skin at 55-70 degrees Celsius, and the method of avoiding danger is adopted: first, keep the heat source (that is, the heating resistor 4 away from the skin of the human body, similar to the way of a hair dryer, That is, a fence is set outside the heat source, and the heating resistors transfer heat to the paper surface with writing through the air. Since the specific heat of the air is relatively small, while the skin contains more water and has a larger specific heat, the burn of the skin in a short time by the hot air is less. For example, the temperature of the tuyere of the hair dryer is higher, but it will not burn the skin in a short time. For example, the heating resistor 4 is fixed on the outer side of the inner upper end of the upper sleeve 6. 3-5mm, the port of the upper sleeve 6 is covered with a layer of grid; the second is to limit the heat contained in the heating resistor 4, that is, to reduce the area of the heating resistor 4 and to reduce the thickness of the heating resistor 4.

The outer casing of the temperature control erasing device is composed of two sleeves. For the convenience of expression, one is called the upper sleeve 6 and the other is called the lower sleeve 7. The upper sleeve and the lower sleeve are connected by an elastic member 8 on the inside. , the commonly used elastic parts are metal springs or elastic plastics or spring sheets, etc.; the lower end of the outer side of the upper sleeve 6 has a ring of metal sheets 9 as a contact point of the power switch 3, and the upper end of the outer side of the lower sleeve 7 has a ring of metal sheets as a power supply. The other contact of the switch 3, press down the upper sleeve 6, compress the elastic member 8 so that the contact on the outside of the upper sleeve 6 contacts the contact on the outside of the lower sleeve 7, and turn on the power switch 3; after the external force is removed, the elastic Part 8 separates the upper sleeve 6 from the lower sleeve 7, and disconnects the power switch 3.

The heating resistor 4 of the temperature control switch is a thin sheet with a thickness of 0.1-0.2 microns and an area of 0.5-1 square centimeters. Its volume is very small, and 0.1 ml of water is roughly equivalent to the volume of 1 drop of water. Splashing on hands, for example, when cooking in a pot, water close to 100 degrees Celsius will be splashed on hands, and a few drops of water will often be poured on hands when getting hot water from a thermos bottle (most of the temperature of the thermos bottle is around 70 degrees), these are generally Neither will cause much harm, mainly because the amount is not large. In addition, the human body mainly contains water, and a small amount of high-temperature water will quickly cool down. The heating resistance sheet belongs to metal, and the heat capacity of water in nature is the largest, and the heat capacity of metal is far smaller than that of water. Therefore, the heat stored in the heating resistance sheet 4 of this design will not be greater than the heat of a drop of 70-degree water, and will not cause skin damage.

The basis for parameter design is described below: For Cr20Ni80 (Cr20% containing chromium and Ni 80% containing Ni) alloy resistance wire, its resistivity is 1.09*10 ^-6 ohm*m, specific heat is 0.5 joule/(gram*degree Celsius), and density is 8 grams /cubic centimeter, the diameter of a circle with an area of 0.5 square centimeters is about 4 millimeters, assuming that the edge of the circle is an electrode, and the center is an electrode, the diameter of the contact point of the design center electrode is 2 millimeters, and the estimate of its resistance is ( 1.09*10 ^-6 ohms*m*dr/(2*3.14*r*d)), where r is the radius, d is the thickness, 2*3.14*r*d is the area of the ring, and its integral is (1.09* 10 ^-6 ohms*meter/(2*3.14*d)*ln(r2/r1)) where r2=4mm, r1=2mm/2=1mm, ln(r2/r1)=ln(4)= 1.386, the existing dry battery or rechargeable battery can roughly provide a current of about 1 ampere, and the voltage is about 1-1.5 volts, so the resistance needs about 1.5 ohms, 1.09*10 ^-6 ohms*m/(2*3.14 *d)* 1.386=1.5 ohm, then d=0.16 microns. For such a thin resistor, the best way is to clamp the ceramic sheet on both sides (it can be realized by vacuum coating on the ceramic sheet), and the heat capacity of the ceramic sheet is generally 0.84*10 ^3J/(kg℃) (heat capacity of dry soil, because ceramics are generally fired from soil) to estimate.

Estimate the time required for the temperature to rise as follows: power = 1.5 volts * 1.5 volts / 1.5 ohms = 1.5 watts, assuming that the thickness of the ceramic sheet is 1 mm, divided into two layers, the diameter is calculated according to 1 cm, and the area = 3.14 * 5 mm * 5 mm=78 square millimeters, the volume is 78 cubic millimeters, the density is 2.4 grams per cubic centimeter according to the soil, its mass is about 0.078*2.4=0.2 grams, and the heat required to raise 1 degree is 0.84*10^3J/(kg℃)*0.2 grams *(°C)=0.168 J; for the heating resistor 4 made of alloy resistance wire, due to its specific heat of 0.5 joules/(g*°C) ratio 0.84*10^3J/(kg°C)= 0.84J/(g°C) =0.84 joules/(grams*degrees Celsius) is small, and the thickness is very small, so it can be ignored, then 1.5 watts*1 second/(0.168 J/degrees)=9 degrees, that is, it can rise by 9 degrees per second, and the normal room temperature is about From 20 degrees Celsius to 60 degrees, it takes about 4-5 seconds. For the estimation of its heat, 1.5 watts*5 seconds/(4.2 joules/(grams*degrees))=1.8 grams*degrees, one gram of water is about 20 drops, 1.8 grams*degrees=36 drops*degrees=1 drop*36 degrees, From room temperature to 60 degrees, there is a temperature difference of about 40 degrees. Therefore, the heat storage of this device is roughly equivalent to the heat released by a drop of water at 60 degrees Celsius when it is lowered to an ambient temperature of 20 degrees Celsius, so it will not cause damage to the skin.

The power source 1 is a dry battery or a rechargeable battery, and is located in the space inside the upper sleeve 6 and the lower sleeve 7 .

The upper sleeve 6 and the lower sleeve 7 form a pen cap, the lower end of the pen cap is threaded, and the pen cap can be threadedly connected to the upper end of the rubbing pen.

The outer edges of the two layers of ceramic sheets have annular grooves with a width of 1 mm and a thickness of 0.05 mm. The two grooves face each other to form a space with a width of 1 mm and a thickness of 0.1 mm. The copper material is used as an electrode to contact the edge of the heating resistance sheet 4, so that the heating resistance sheet 4 conducts electricity more uniformly, thereby making the temperature distribution more uniform. From this design, the current flows to the center. The current density at the center is higher than that at the edge, so the temperature is slightly higher. However, since metal and ceramics are relatively good heat-conducting materials, the temperature can be basically uniform.

Claims (10)

1. The temperature-controlled erasing device used by the rubbing pen is characterized by: a power supply (1) connected in series with two switches, one switch is a temperature control switch, referred to as a temperature control switch (2), and the other switch is a power supply The connection switch, referred to as the power switch (3); the temperature control switch is composed of a heating resistor (4) and a bimetal (5), the heating resistor generates heat when the power is turned on, and the bimetal reaches the designed temperature disconnect the circuit. 2. The temperature-controlled erasing device for the rubbing pen according to claim 1, characterized in that: the designed temperature is 55-70 degrees Celsius. 3. The temperature-controlled erasing device for a friction-erasable pen according to claim 1, characterized in that: the outer casing of the temperature-controlled erasing device is composed of two sleeves, called the upper sleeve (6) and the lower sleeve The sleeve (7), the upper sleeve and the lower sleeve are connected on the inside by an elastic member (8); the lower end of the upper sleeve (6) outside has a circle of metal sheet (9) as a contact of the power switch (3) , the upper end of the outer side of the lower sleeve (7) has a ring of metal sheets as another contact point of the power switch (3), press down on the upper sleeve (6), and compress the elastic member (8) so that the outer side of the upper sleeve (6) The contact contacts the contact on the outside of the lower sleeve (7), and the power switch (3) is turned on. 4. The temperature-controlled erasing device used by the rubbing pen according to claim 1, characterized in that: the heating resistor (4) of the temperature-controlled switch is a thin sheet with a thickness of 0.1-0.2 microns and an area of 0.5 -1 square centimeter. 5. The temperature-controlled erasing device for a friction-erasable pen according to claim 3, characterized in that: the heating resistor (4) is fixed on the outer side of the inner upper end of the upper sleeve (6), and the heating resistor (4) The distance from the outer surface of the upper sleeve (6) to the port is 3-5mm, and the port of the upper sleeve (6) is covered with a layer of grid. 6. The temperature-controlled erasing device used by the rubbing pen according to claim 3, characterized in that: the power supply (1) is a dry battery or a rechargeable battery, located on the upper sleeve (6) and the lower sleeve (7) ) inside the space. 7. The temperature-controlled erasing device for a friction-erasable pen according to claim 3, characterized in that: the upper sleeve (6) and the lower sleeve (7) form a pen cap, the lower end of the pen cap is threaded, and the pen cap can pass through Threaded to the upper end of the rub-and-rub pen. 8. The temperature-controlled erasing device used by the rubbing pen according to claim 4, characterized in that: there is a layer of non-conductive ceramic sheet on both sides of the heating resistance sheet (4), and the thickness of the ceramic sheet is between 0.5- 1 mm, the center of the inner ceramic sheet has a circular hole with a diameter of 2-3 mm for one end of the bimetallic sheet (5) to contact the heating resistance sheet (4). 9. The temperature-controlled erasing device used by the friction-erasable pen according to claim 8, characterized in that: the outer edges of the two layers of ceramic sheets have circular grooves with a width of 1 mm and a thickness of 0.05 mm, and the two layers Two ring-shaped grooves face to form a ring-shaped space with a width of 1 mm and a thickness of 0.1 mm. In this ring-shaped space, a ring of copper material is arranged as an electrode to contact the edge of the heating resistor (4). 10. The temperature-controlled erasing device for the rubbing pen according to claim 3, characterized in that: the circumference of the upper end surface of the upper sleeve is fixed with balls.