JP7598841B2 - Wire winding bobbin and winding device - Google Patents

Description

This disclosure relates to a bobbin for winding wire and a winding device.

Traditionally, to reduce transportation costs, metal wire has been transported wound around a relatively light plastic bobbin. When winding wire around such a bobbin, the tension in the wire generates stress that deforms the bobbin body (body). This stress causes a bending moment to act on the flange in a direction that bends the flange outward.

However, because the flange has low rigidity, it is prone to deformation and collapse, causing the wire wound around the bobbin body (body) to collapse, making it impossible to pay out the wire efficiently.

To solve this problem, Patent Document 1 proposes a resin winding bobbin with higher ribs on the flange and thicker body and flange sections.

Utility Model Registration No. 3065847

However, resin is prone to sink marks (a phenomenon in which the volume of resin shrinks as it solidifies, causing defects such as dents on the surface), and bobbins made of resin have the problem that sink marks can cause the roundness and smoothness of the body and flange to be lost, leading to breakage.

The objective of this disclosure is to provide a wire winding bobbin and a winding device that can efficiently unwind wire.

The wire winding bobbin according to the present disclosure comprises a straight body portion having an inner peripheral wall that forms an axial hole penetrating along the axial direction and an outer peripheral wall that is positioned on either side of a cylindrical internal space that surrounds the inner peripheral wall, flange portions located on both ends of the straight body portion, and a lid portion attached to at least one of the flange portions. At least the straight body portion and the flange portion are made of ceramics.

The wire winding bobbin according to the present disclosure comprises a straight body portion having an inner peripheral wall that forms an axial hole penetrating along the axial direction and an outer peripheral wall that is positioned on either side of a cylindrical internal space that surrounds the inner peripheral wall, and flange portions that are positioned on both ends of the straight body portion and have through holes that connect to the internal space along the axial direction. The straight body portion and the flange portions are made of ceramics.

The winding device according to the present disclosure uses the above-mentioned wire winding bobbin.

The wire winding bobbin and winding device disclosed herein are capable of efficiently unwinding wire.

FIG. 2 is a plan view of a wire winding bobbin according to a non-limiting embodiment of the present disclosure. 2 is a cross-sectional view of the wire winding bobbin shown in FIG. 1 taken along line II-II. 3 is an enlarged view of the periphery of a first bonding layer and a second bonding layer in the wire winding bobbin shown in FIG. 2 . FIG. FIG. 2 is a plan view of a wire winding bobbin according to a non-limiting embodiment of the present disclosure. 5 is a cross-sectional view taken along line VV of the wire winding bobbin shown in FIG. 4. 6 is an enlarged view of the periphery of a first bonding layer and a second bonding layer in the wire winding bobbin shown in FIG. 5 .

<Wire winding bobbin>
Hereinafter, a wire winding bobbin according to a non-limiting embodiment of the present disclosure will be described in detail with reference to the drawings. However, in each of the drawings referred to below, for the sake of convenience, only the main components necessary for explaining the embodiment are shown in a simplified form. Therefore, the wire winding bobbin may include any component not shown in each of the drawings referred to. Furthermore, the dimensions of the components in each drawing do not faithfully represent the dimensions of the actual components and the dimensional ratios of each component.

The wire winding bobbin 1 (hereinafter sometimes referred to as "bobbin 1") comprises a straight body portion 2, a flange portion 3, and a lid portion 4, as shown in the example in Figures 1 to 3.

The straight body portion 2 has an inner peripheral wall 22 that forms an axial hole 21 that penetrates along the axis S direction, and an outer peripheral wall 24 that is positioned on either side of a cylindrical internal space 23 that surrounds the inner peripheral wall 22. Because the straight body portion 2 has the internal space 23, the bobbin 1 can be made lighter, and transportation costs can be reduced.

The inner peripheral wall 22 and the outer peripheral wall 24 may be cylindrical. A wire can be wound around the outer peripheral surface 241 of the outer peripheral wall 24. The shaft hole 21 can function as a portion for transmitting rotation from a winding device. For example, when the rotating shaft of the winding device is inserted into the shaft hole 21 and the bobbin 1 is rotated, the wire can be wound around the outer peripheral surface 241 of the outer peripheral wall 24. Examples of the wire can include fiber and wire.

The flanges 3 are attached to both ends of the straight body portion 2. Therefore, the number of flanges 3 is two. The configuration of the two flanges 3 may be the same or different. For convenience, the two flanges 3 may be referred to as a first flange 31 and a second flange 32. The outer diameter of the flange 3 may be larger than the outer diameter of the straight body portion 2. The outer periphery of the flange 3 may be circular.

The lid portion 4 is attached to at least one of the flange portions 3. For example, as shown in the example in FIG. 2, the lid portion 4 may be attached to the first flange portion 31. By attaching the lid portion 4 to the flange portion 3, the inner peripheral wall 22 and the outer peripheral wall 24 can be formed into various shapes before attachment, which increases the degree of freedom in design. The lid portion 4 may be attached to the flange portion 3 so as to close the internal space 23 exposed from the flange portion 3.

Here, at least the straight body portion 2 and the flange portion 3 are made of ceramics. This makes them more rigid than when they are made of resin, and so roundness and smoothness are less likely to be lost. This makes it possible to pay out the wire efficiently.

The lid 4 may also be made of ceramics. The ceramics may have aluminum oxide as its main component. The main component may mean the component that is the most abundant out of a total of 100% by mass of all components that make up the ceramics, and the main component is, for example, 80% by mass or more and 99.8% by mass or less. When the main component of the ceramics is aluminum oxide, it may contain at least one of silicon, magnesium, and calcium as an oxide.

Each component contained in the ceramic is identified using an X-ray diffraction apparatus using CuKα radiation, and the content of each component is determined, for example, using an ICP (Inductively Coupled Plasma) emission spectrometer or an X-ray fluorescence analyzer.

The body 2 and the flange 3 may be integrally formed. In this case, the heat treatment required only to join the body 2 and the flange 3 can be eliminated, and the bobbin 1 can be obtained at low cost. Note that an integrally formed product may mean that the parts are not processed separately and then joined together, but are made integrally from the same material without being joined together. For example, a cylindrical molded body may be produced by cold isostatic pressing (CIP) molding, and the body 2 and flange 3 may be formed on this molded body by cutting or other processing.

The flange 3 may be flat, or may have a recess 33, as in the example shown in FIG. 2. That is, at least one of the flanges 3 may have a recess 33 that opens in the axial S direction. The lid 4 may be flat, or may be attached to the bottom surface of the recess 33. The bobbin 1 may have a first bonding layer 5 between the main surface 41 of the lid 4 on the side of the straight body 2 and the first bottom surface 331 on the side of the outer wall 24 of the recess 33, as in the example shown in FIG. 3. In these cases, the straight body 2 is sealed from the axial S direction, so that the cylindricity of the outer wall 24 of the straight body 2 is less likely to be impaired even if the fiber or wire is repeatedly wound around it.

The first bonding layer 5 may be made of ceramics with the same main component as the ceramics that make up the body portion 2 and the flange portion 3. In this case, the lid portion 4 can be firmly fixed to the flange portion 3. Note that the material of the first bonding layer 5 is not limited to the exemplified materials as long as it can bond the main surface 41 of the lid portion 4 and the first bottom surface 331 of the recess 33. In addition, the thickness of the first bonding layer 5 may be set to, for example, approximately 40 μm or more and 60 μm or less.

The first bonding layer 5 may have a first convex portion 51 connected to the first bonding layer 5. The first convex portion 51 may be in contact with at least one of the outer peripheral surface 241 and the inner peripheral surface 242 of the outer peripheral wall 24, and the main surface 41 of the lid portion 4. For example, as shown in an example in FIG. 3, the first convex portion 51 may be in contact with the inner peripheral surface 242 of the outer peripheral wall 24 and the main surface 41 of the lid portion 4. When the first convex portion 51 is in contact with at least one of the outer peripheral surface 241 and the inner peripheral surface 242 of the outer peripheral wall 24, and the main surface 41 of the lid portion 4, the first bonding layer 5 is not easily eroded even when used in a highly corrosive atmosphere, so that the bobbin 1 can be used for a long period of time. The main component of the first convex portion 51 may be the same as the main component of the first bonding layer 5.

The relative density of the ceramics that make up the body portion 2 and flange portion 3 is, for example, 95% or more. If the relative density is within the above range, the number of open pores will be reduced, so that even if the wire comes into contact with the outer peripheral surface 241 of the outer peripheral wall 24 or the inward facing surfaces that sandwich the outer peripheral wall 24 on both sides of the flange portion 3, grains are less likely to fall out from around the open pores on the contacting surfaces.

The ceramic has a plurality of closed pores, and the value obtained by subtracting the average diameter of the closed pores from the average distance between the centers of gravity of the closed pores is preferably 4 μm or more and 20 μm or less.

When the value obtained by subtracting the average diameter of the closed pores from the average distance between the centers of gravity of the closed pores is 4 μm or more, the closed pores are relatively dispersed, and the mechanical strength and rigidity of the ceramics are high. When the value obtained by subtracting the average equivalent circle diameter of the closed pores from the average distance between the centers of gravity of the closed pores is 20 μm or less, even if the ceramic is placed in an environment exposed to repeated temperature increases and decreases and microcracks originating from the contours of the closed pores occur, there is a high probability that their extension will be blocked by the surrounding closed pores.

If the lid portion 4 is made of ceramics, its relative density should be 95% or more.

Relative density is expressed as a percentage (proportion) of the apparent density of a ceramic to the theoretical density calculated from the ratio of the identified components of the ceramic. The apparent density of ceramics can be determined in accordance with JIS R 1634-1998.

When the lid 4 is made of ceramics, it is preferable that the ceramics have a plurality of closed pores, and the value obtained by subtracting the average diameter of the closed pores from the average distance between the centers of gravity of the closed pores is 4 μm or more and 20 μm or less. The same effect as described above can be obtained.

To determine the distance between the centers of gravity of closed pores contained in a ceramic, first cut out a portion of the ceramic and polish the surface to be observed with diamond abrasive grains until it becomes a mirror surface. Observe using an optical microscope, and the magnification may be set to, for example, 200 times. The observation range of the surface to be observed is set to, for example, a horizontal length of 290 μm and a vertical length of 217 μm. The average value of the distance between the centers of gravity may be determined by applying the distance between the centers of gravity method of the image analysis software "Azokun (Ver. 2.52)" (registered trademark, manufactured by Asahi Kasei Engineering Co., Ltd., hereinafter referred to simply as image analysis software) to this observation range.

To determine the average diameter of the closed pores contained in ceramics, the observation range described above can be targeted and a method called particle analysis using image analysis software can be applied to determine the average diameter.

In the analysis, the setting conditions for particle analysis and the distance between centers of gravity method are: particle brightness is dark, the binarization method is manual, the threshold is 193, the small figure removal area is 0.3 μm ² , and a noise removal filter is enabled.

In the above analysis, the threshold value was set to 193, but the threshold value may be adjusted according to the brightness of the image, which is the observation range, by setting the particle brightness to dark, the binarization method to manual, the small figure removal area to 0.3 ^μm2 , and a noise removal filter, and then adjusting the threshold value so that the markers appearing in the image match the shapes of the closed pores. The average diameter of the closed pores may be the average value of the circle equivalent diameter.

The first convex portion 51 and the lid portion 4 may have closed pores. More specifically, the first convex portion 51 and the lid portion 4 may have a plurality of closed pores. The average diameter of the closed pores of the first convex portion 51 may be 1.5 times or less the average diameter of the closed pores of the lid portion 4. In this case, since the closed pores that are the source of fracture in the first convex portion 51 are small, the occurrence of microcracks originating from the closed pores of the first convex portion 51 and the progression of the microcracks to the straight body portion 2 and the lid portion 4 can be suppressed.

The average diameter of the closed pores of the first convex portion 51 may be 0.8 times or more the average diameter of the closed pores of the lid portion 4. The average diameter of the closed pores of the first convex portion 51 may be smaller than the average diameter of the closed pores of the lid portion 4. The average diameter of the closed pores is not limited to a specific value. For example, the average diameter of the closed pores of the first convex portion 51 may be set to approximately 0.7 μm or more and 2 μm or less. The average diameter of the closed pores of the lid portion 4 may be set to approximately 0.8 μm or more and 3 μm or less.

The average aspect ratio of the closed pores of the first protrusions 51 may be 2 or less.
The aspect ratio of a closed pore is a value expressed as the ratio of the maximum length of a closed pore to the minimum width of the closed pore, and the closer this value is to 1, the closer it is to a perfect circle.

Having multiple closed pores relieves stress, and when the average aspect ratio of the closed pores is 2 or less, there are many closed pores that are close to spherical, which reduces the stress generated around the closed pores and makes it less likely for cracks to occur starting from these peripheries.

The average diameter of the closed pores of the first convex portion 51 and the lid portion 4 may be measured, for example, by cross-sectional observation using a scanning electron microscope. A sample including a part of the lid portion 4 to be measured and the first convex portion 51 in contact with the lid portion 4 is cut out and embedded in a polyester resin to form a cylindrical sample. Here, the cross section of the sample may be mirror-finished using diamond abrasive grains. The magnification may be set to, for example, 500 times. The observation range in which the cross section of the sample is observed may be set to, for example, a horizontal length of 256 μm and a vertical length of 192 μm, and the lid portion 4 and the first convex portion 51 may be divided. Each of these divided observation ranges may be observed, and the average diameter of the closed pores may be obtained by applying a method called particle analysis of image analysis software. The average diameter of the closed pores may be the average value of the circle equivalent diameter.

The average aspect ratio of closed pores can also be measured using the same method as described above.

In the analysis, the conditions for particle analysis and the distance between centers of gravity method were set as follows: particle brightness was dark, the binarization method was manual, the threshold was 70 to 100, the small figure removal area was 0.3 μm ^{2 ,} and a noise removal filter was used.

In the above analysis, the threshold value was set to 70 to 100, but the threshold value can be adjusted according to the brightness of the image, which is the observation range. The particle brightness is set to dark, the binarization method is set to manual, the small figure removal area is set to 0.3 ^μm2 , and a noise removal filter is used. The threshold value can then be adjusted so that the markers appearing in the image match the shapes of closed pores.

The bobbin 1 may have a second bonding layer 6 between the main surface 41 of the lid 4 on the side of the straight body 2 and the second bottom surface 332 on the side of the inner wall 22 of the recess 33. In this case, the rigidity of the straight body 2 is higher than when it is fixed only by the first bonding layer 5, so that the cylindricity of the outer wall 24 of the straight body 2 is less likely to be impaired even if the fiber or wire is repeatedly wound around it.

The second bonding layer 6 may be made of ceramics with the same main component as the ceramics that make up the body portion 2 and the flange portion 3. In this case, the lid portion 4 can be firmly fixed to the flange portion 3. Note that the material of the second bonding layer 6 is not limited to the exemplified materials as long as it can bond the main surface 41 of the lid portion 4 and the second bottom surface 332 of the recess 33. In addition, the thickness of the second bonding layer 6 may be set to, for example, about 40 μm or more and 60 μm or less.

The second bonding layer 6 may have a second protrusion 61 connected to the second bonding layer 6. The second protrusion 61 may be in contact with at least one of the inner peripheral surface 221 and the outer peripheral surface 222 of the inner peripheral wall 22, and the main surface 41 of the lid portion 4. For example, as shown in FIG. 3, the second protrusion 61 may be in contact with the outer peripheral surface 222 of the inner peripheral wall 22 and the main surface 41 of the lid portion 4. When the second protrusion 61 is in contact with at least one of the inner peripheral surface 221 and the outer peripheral surface 222 of the inner peripheral wall 22, and the main surface 41 of the lid portion 4, the second bonding layer 6 is not easily eroded even when used in a highly corrosive atmosphere, so that the bobbin 1 can be used for a long period of time. The main component of the second protrusion 61 may be the same as the main component of the second bonding layer 6.

The second convex portion 61 may have closed pores. More specifically, the second convex portion 61 may have a plurality of closed pores. The average diameter of the closed pores of the second convex portion 61 may be 1.5 times or less the average diameter of the closed pores of the lid portion 4. In this case, since the closed pores that are the source of destruction in the second convex portion 61 are small, the occurrence of microcracks originating from the closed pores of the second convex portion 61 and the progression of the microcracks to the straight body portion 2 and the lid portion 4 can be suppressed.

The average diameter of the closed pores of the second convex portion 61 may be 0.8 times or more the average diameter of the closed pores of the lid portion 4. The average diameter of the closed pores of the second convex portion 61 may be smaller than the average diameter of the closed pores of the lid portion 4. The average diameter of the closed pores of the second convex portion 61 is not limited to a specific value. For example, the average diameter of the closed pores of the second convex portion 61 may be set to approximately 1 μm or more and 2 μm or less.

The average aspect ratio of the closed pores of the second protrusions 61 may be 2 or less.
Having a plurality of closed pores relieves stress, and when the average aspect ratio of the closed pores is 2 or less, there are many closed pores that are close to spherical, which reduces stress generated around the closed pores and makes it less likely for cracks to occur starting from these pores.

The average diameter of the closed pores of the second convex portion 61 and the lid portion 4 may be measured using the same method as that used to measure the average diameter of the closed pores of the first convex portion 51 and the lid portion 4.

The recess 33 may have a third bottom surface 333 on the outer periphery side of the first bottom surface 331. The first bottom surface 331 may be located shallower than the third bottom surface 333. In other words, the third bottom surface 333 may be located farther from the opening of the recess 33 than the first bottom surface 331. If the first bottom surface 331 is located shallower than the third bottom surface 333, the first protrusion 51 on the outer periphery 241 side of the outer wall 24 of the straight body portion 2 can be easily removed if required.

The bobbin 1 may include a reinforcing rib as described in Patent Document 1. For example, the reinforcing rib may connect the outer surface 42 of the lid portion 4 and the inner surface 34 of the flange portion 3 that forms the recess 33. In this case, the reinforcing rib that connects the outer surface 42 of the lid portion 4 and the inner surface 34 of the flange portion 3 that forms the recess 33 does not have to be on the third bottom surface 333. In other words, the reinforcing rib described above does not have to be in contact with the third bottom surface 333. In this case, the increase in mass due to the reinforcing rib can be suppressed.

The lid portion 4 may be disk-shaped, and its outer diameter may be within ±1 mm of the outer diameter of the outer wall 24. In this case, the progression of microcracks from the outer wall 24 of the straight body portion 2 toward the lid portion 4 is suppressed.

The outer surface 42 of the lid portion 4 may be on an extension of the outer surface 241 of the outer wall 24. In this case, it becomes even easier to suppress the progression of microcracks from the outer wall 24 of the straight body portion 2 toward the lid portion 4.

As shown in the example in FIG. 2, the cover 4 may have a hole 43 that penetrates the cover 4 along the axis S and connects to the shaft hole 21. The hole 43 can function together with the shaft hole 21 as a part for transmitting rotation from the winding device.

The lid portion 4 may have a through hole 44 that connects to the internal space 23 along the axis S direction. The through hole 44 may function as a part for transmitting rotation from the winding device. The through hole 44 may be multiple, as in the example shown in FIG. 1. When there are multiple through holes 44, the number of the through holes 44 may be 2 or more and 10 or less. The multiple through holes 44 may be positioned at equal intervals along the circumferential direction of the lid portion 4. Note that, as in the example shown in FIG. 2, the flange portion 3 (second flange portion 32) may also have a through hole 35 that connects to the internal space 23 along the axis S direction, similar to the lid portion 4. The through hole 35 may be multiple, similar to the through hole 44 of the lid portion 4. When there are multiple through holes 35, the number of the through holes 35 may be 2 or more and 10 or less. The multiple through holes 35 may be positioned at equal intervals along the circumferential direction of the flange portion 3.

The size of the bobbin 1 may be set appropriately depending on the wire to be wound. For example, the length of the straight body portion 2 in the direction along the axis S may be set to about 60 mm or more and 200 mm or less. The outer diameter of the outer wall 24 of the straight body portion 2 may be set to about 60 mm or more and 200 mm or less. The outer diameter of the flange portion 3 may be set to about 130 mm or more and 270 mm or less. The thickness of the flange portion 3 in the direction along the axis S may be set to about 10 mm or more and 20 mm or less.

Next, a wire winding bobbin 1A (hereinafter, sometimes referred to as "bobbin 1A") according to a non-limiting embodiment of the present disclosure will be described with reference to the drawings. Below, the differences between bobbin 1A and bobbin 1 will be mainly described, and detailed descriptions of the features that have the same configuration as bobbin 1 may be omitted.

As shown in the example in Figures 4 to 6, the bobbin 1A comprises a straight body portion 2 and a flange portion 3. The straight body portion 2 has an inner peripheral wall 22 that forms an axial hole 21 penetrating along the axial S direction, and an outer peripheral wall 24 that is positioned on either side of a cylindrical internal space 23 that surrounds the inner peripheral wall 22. The flange portions 3 are attached to both ends of the straight body portion 2 and comprise through holes 35 that connect to the internal space 23 along the axial S direction.

The body portion 2 and flange portion 3 are made of ceramics. This makes them more rigid than when they are made of resin, and therefore circularity and smoothness are less likely to be lost. Also, by attaching one of the flange portions 3 to the body portion 2, the inner peripheral wall 22 and the outer peripheral wall 24 can be formed into various shapes before attachment, which increases the degree of freedom in design.

Either one of the flanges 3 and the straight body portion 2 may be integrally formed. For example, as shown in the example in FIG. 5, the second flange 32 and the straight body portion 2 may be integrally formed. When either one of the flanges 3 and the straight body portion 2 are integrally formed, the heat treatment just for joining the straight body portion 2 and the flange 3 can be eliminated, and the bobbin 1A can be obtained at low cost.

Either of the flanges 3 and the straight body 2 may be joined. For example, as shown in the example in FIG. 5, the first flange 31 and the straight body 2 may be joined. As shown in the example in FIG. 6, the bobbin 1A may have a first bonding layer 5 between the main surface 36 of the flange 3 on the straight body 2 side and the end surface 243 of the outer peripheral wall 24 on the flange 3 side. In this case, the straight body 2 is sealed from the axial S direction, so that the cylindricity of the outer peripheral wall 24 of the straight body 2 is less likely to be impaired even if the fiber or wire is repeatedly wound around it.

The first bonding layer 5 may have a first protruding portion 51 connected to the first bonding layer 5. The first protruding portion 51 may be in contact with at least one of the inner peripheral surface 242 and the outer peripheral surface 241 of the outer peripheral wall 24, and the main surface 36 of the flange portion 3. For example, as shown in an example in FIG. 6, the first protruding portion 51 may be in contact with the inner peripheral surface 242 of the outer peripheral wall 24 and the main surface 36 of the flange portion 3. When the first protruding portion 51 is in contact with at least one of the inner peripheral surface 242 and the outer peripheral surface 241 of the outer peripheral wall 24, and the main surface 36 of the flange portion 3, the first bonding layer 5 is not easily eroded even when used in a highly corrosive atmosphere, so the bobbin 1A can be used for a long period of time.

The flange 3 may have closed pores. More specifically, the flange 3 may have a plurality of closed pores. The average diameter of the closed pores in the first convex portion 51 may be 1.5 times or less the average diameter of the closed pores in the flange 3. In this case, since the closed pores that are the source of fracture in the first convex portion 51 are small, the occurrence of microcracks originating from the closed pores in the first convex portion 51 and the progression of the microcracks to the straight body portion 2 and the flange 3 can be suppressed.

The average diameter of the closed pores of the first convex portion 51 may be 0.8 times or more the average diameter of the closed pores of the flange portion 3. The average diameter of the closed pores of the first convex portion 51 may be smaller than the average diameter of the closed pores of the flange portion 3. The average diameter of the closed pores of the flange portion 3 is not limited to a specific value. For example, the average diameter of the closed pores of the flange portion 3 may be set to approximately 0.8 μm or more and 3 μm or less.

The average aspect ratio of the closed pores of the first protrusions 51 may be 2 or less.
Having a plurality of closed pores relieves stress, and when the average aspect ratio of the closed pores is 2 or less, there are many closed pores that are close to spherical, which reduces stress generated around the closed pores and makes it less likely for cracks to occur starting from these pores.

The average diameter of the closed pores in the first convex portion 51 and the flange portion 3 may be measured using the same method as that used to measure the average diameter of the closed pores in the first convex portion 51 and the lid portion 4.

Either of the flanges 3 and the straight body 2 may be joined. For example, as shown in the example in FIG. 5, the first flange 31 and the straight body 2 may be joined. As shown in the example in FIG. 6, the bobbin 1A may have a second joining layer 6 between the main surface 36 of the flange 3 on the straight body 2 side and the end surface 223 of the inner wall 22 on the flange 3 side. In this case, the straight body 2 is sealed from the axial S direction, so that the cylindricity of the outer wall 24 of the straight body 2 is less likely to be impaired even if the fiber or wire is repeatedly wound around it.

The second bonding layer 6 may have a second protrusion 61 connected to the second bonding layer 6. The second protrusion 61 may be in contact with at least one of the inner circumferential surface 221 and the outer circumferential surface 222 of the inner circumferential wall 22, and the main surface 36 of the flange portion 3. For example, as shown in an example in FIG. 6, the second protrusion 61 may be in contact with the outer circumferential surface 222 of the inner circumferential wall 22 and the main surface 36 of the flange portion 3. When the second protrusion 61 is in contact with at least one of the inner circumferential surface 221 and the outer circumferential surface 222 of the inner circumferential wall 22, and the main surface 36 of the flange portion 3, the second bonding layer 6 is not easily eroded even when used in a highly corrosive atmosphere, so the bobbin 1A can be used for a long period of time.

The average diameter of the closed pores in the second convex portion 61 may be 1.5 times or less the average diameter of the closed pores in the flange portion 3. In this case, since the closed pores that are the source of destruction in the second convex portion 61 are small, it is possible to suppress the occurrence of microcracks originating from the closed pores in the second convex portion 61 and the progression of the microcracks to the straight body portion 2 and the flange portion 3. The average diameter of the closed pores in the second convex portion 61 may be 0.8 times or more the average diameter of the closed pores in the flange portion 3. The average diameter of the closed pores in the second convex portion 61 may be smaller than the average diameter of the closed pores in the flange portion 3.

The average diameter of the closed pores in the second convex portion 61 and the flange portion 3 can be measured using the same method as that used to measure the average diameter of the closed pores in the first convex portion 51 and the lid portion 4.

The average aspect ratio of the closed pores of the second protrusions 61 may be 2 or less.
Having a plurality of closed pores relieves stress, and when the average aspect ratio of the closed pores is 2 or less, there are many closed pores that are close to spherical, which reduces stress generated around the closed pores and makes it less likely for cracks to occur starting from these pores.

As shown in the example in FIG. 5, the flange 3 may have a hole 37 that passes through the flange 3 along the axis S and connects to the shaft hole 21. The hole 37 can function together with the shaft hole 21 as a part for transmitting rotation from the winding device.

Next, a method for manufacturing the wire winding bobbin according to the present disclosure will be described.
First, a case where the straight body portion 2 and the flange portion 3 of the wire winding bobbin are integrally formed will be described.

First, a powder mixture is weighed out so that the magnesium hydroxide is 0.3 mass% converted to oxide (MgO), silicon oxide is 0.04 mass%, calcium carbonate is 0.02 mass% converted to oxide (CaO), and the remainder is aluminum oxide. The powder mixture is then placed in a rotary mill together with a solvent such as water and mixed with ceramic balls made of aluminum oxide with a purity of 99.5% to 99.99%.

Next, a molding binder such as polyvinyl alcohol, polyethylene glycol, or acrylic resin is added and mixed to obtain a slurry. Here, the amount of molding binder added is 2 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the mixed powder.

Next, the slurry is spray-dried using a spray drying device to obtain granules. The granules are then subjected to a CIP process at a pressure of, for example, 80 MPa to 100 MPa to obtain a cylindrical compact. This compact is then cut to form the flange 3, straight body 2, shaft hole 21, internal space 23, through-holes, recesses 33, etc.

The wire winding bobbin of the present disclosure can be obtained by sintering the machined molded body in an air atmosphere at a temperature of 1500°C or higher and 1700°C or lower for 5 hours or higher and 8 hours or lower.

Next, we will explain the manufacturing method of a wire winding bobbin in which the straight body portion 2 and the flange portion 3 are joined by the first joining layer 5 and the second joining layer 6.

The granules obtained by the above-mentioned method are molded in the same manner to obtain cylindrical and disk-shaped bodies. The cylindrical body is machined to form the flange 3, straight body 2, axial hole 21, internal space 23, through hole, recess 33, etc., to form precursor A in which the straight body 2 and flange 3 are connected along the axis S direction. The disk-shaped body is machined to form precursor B for the lid 4 with a through hole 44.

Here, a paste containing aluminum oxide powder, cellulose polysaccharides, and a solvent is prepared.

Specifically, a solvent such as water or ethanol is added to the mixed powder so that the volume ratio of mixed powder to solvent is 55-60:40-45, and the total of this solvent and mixed powder is 100 parts by mass. To this 100 parts by mass, 8 parts by mass to 20 parts by mass of cellulose polysaccharide is added, and these are placed in a storage container in a stirring device and mixed and stirred to obtain a paste.

Here, the cellulose polysaccharide is, for example, at least one of methyl cellulose, ethyl cellulose, ethyl methyl cellulose, hydroxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, carboxymethyl cellulose, carboxymethyl ethyl cellulose, and carboxyethyl cellulose.

The average diameter of the closed pores may be adjusted, for example, by the conditions when stirring the paste. For example, if the average diameter of the closed pores of the first convex portion 51 is to be 1.5 times or less than the average diameter of the closed pores of the lid portion 4, the rotation speed of the stirring device may be set to 1200 rpm or more and 1600 rpm or less, and the rotation time may be set to 5 minutes or more and 15 minutes or less. Also, if the average diameter of the closed pores of the first convex portion 51 is to be smaller than the average diameter of the closed pores of the lid portion 4, the rotation speed may be increased to 1400 rpm or more and 1600 rpm or less, and the rotation time may be set to 5 minutes or more and 15 minutes or less.

By stirring the paste within this range of stirring conditions, it is possible to adjust the average diameter of the closed pores to the above-mentioned relationship. The above points can also be applied to adjusting the average diameter of the closed pores in the second convex portion 61 and the flange portion 3.

The paste is then applied to the opposing surfaces of at least one of precursor A and precursor B, and the opposing surfaces are then placed facing each other. Precursor A and precursor B are then pressurized, for example, at a pressure of 20 kPa or more and 40 kPa or less, to obtain a precursor in which precursor A and precursor B are connected along the axis S direction.

Next, the paste is dried by holding it at room temperature for 12 to 48 hours while adjusting the humidity. The precursor is then fired in an air atmosphere at a temperature of 1500°C to 1700°C for 5 to 8 hours, thereby obtaining the wire winding bobbin of the present disclosure.

The above manufacturing method is one example of a method for manufacturing the wire winding bobbin of the present disclosure. Therefore, it goes without saying that the wire winding bobbin of the present disclosure is not limited to those manufactured by the above manufacturing method.

<Winding device>
Next, a winding device according to a non-limiting embodiment of the present disclosure will be described using the above-described bobbin 1 as an example.

A non-limiting embodiment of the winding device uses the above-mentioned bobbin 1. This allows the wire to be efficiently unwound. Note that the winding device may use the above-mentioned bobbin 1A instead of the bobbin 1.

Although the above provides examples of embodiments of the present disclosure, it goes without saying that the present disclosure is not limited to the above embodiments and may be any embodiment without departing from the gist of the present disclosure.

REFERENCE SIGNS LIST 1: Wire winding bobbin 2: Body portion 21: Shaft hole 22: Inner peripheral wall 221: Inner peripheral surface 222: Outer peripheral surface 223: End surface on the flange portion side 23: Internal space 24: Outer peripheral wall 241: Outer peripheral surface 242: Inner peripheral surface 243: End surface on the flange portion side 3: Flange portion 31: First flange portion 32: Second flange portion 33: Recessed portion 331: First bottom surface 332: Second bottom surface 333: Third bottom surface 34: Inner surface 35: Through hole 36: Main surface on the body portion side 37: Hole 4: Lid portion 41: Main surface on the body portion side 42: Outer surface 43: Hole 44: Through hole 5: First bonding layer 51: First protruding portion 6: Second bonding layer 61: Second protruding portion S: Shaft

Claims (18)

a straight body portion having an inner peripheral wall that defines an axial hole penetrating along an axial direction and an outer peripheral wall that is positioned on either side of a cylindrical internal space that surrounds the inner peripheral wall;
flanges located at both ends of the straight body portion;
and a lid portion attached to at least one of the flange portions,
At least the body portion and the flange portion are made of ceramics,
A wire winding bobbin having a first bonding layer between the lid portion and the flange portion . The wire winding bobbin according to claim 1, wherein the ceramic has a plurality of adjacent closed pores, and the value obtained by subtracting the average value of the circle equivalent diameter of the closed pores from the average value of the distance between the centers of gravity of the closed pores is 4 μm or more and 20 μm or less. At least one of the flange portions has a recess that opens in the axial direction,
The lid portion has a flat plate shape and is attached to a bottom surface of the recessed portion,
3 . The wire winding bobbin according to claim 1 , wherein the first bonding layer is provided between a main surface of the lid portion on the side of the straight body portion and a first bottom surface of the recess on the side of the outer circumferential wall. the first bonding layer has a first protruding portion connected to the first bonding layer, the first protruding portion being in contact with at least one of an outer peripheral surface and an inner peripheral surface of the outer peripheral wall and the main surface;
the first protrusion and the lid have closed pores,
4. The wire winding bobbin according to claim 3, wherein an average diameter of closed pores in the first projection is 1.5 times or less an average diameter of closed pores in the lid. the first bonding layer has a first convex portion connected to the first bonding layer, the first convex portion being in contact with at least one of an outer peripheral surface and an inner peripheral surface of the outer peripheral wall and the main surface;
the first protrusion has closed pores,
5. The wire winding bobbin according to claim 3, wherein an average aspect ratio of closed pores of said first projections is 2 or less. A wire winding bobbin according to any one of claims 3 to 5, having a second bonding layer between the main surface and a second bottom surface on the inner wall side of the recess. the second bonding layer has a second convex portion connected to the second bonding layer, the second convex portion being in contact with at least one of an inner circumferential surface and an outer circumferential surface of the inner circumferential wall and the main surface;
the second protrusion and the lid have closed pores,
7. The wire winding bobbin according to claim 6, wherein an average diameter of closed pores in the second protrusion is 1.5 times or less an average diameter of closed pores in the lid. the second bonding layer has a second convex portion connected to the second bonding layer, the second convex portion being in contact with at least one of an inner circumferential surface and an outer circumferential surface of the inner circumferential wall and the main surface;
the second protrusion has closed pores,
8. The wire winding bobbin according to claim 6, wherein an average aspect ratio of closed pores of said second projections is 2 or less. A wire winding bobbin according to any one of claims 3 to 8, wherein the recess has a third bottom surface on the outer peripheral side of the first bottom surface, and the first bottom surface is located shallower than the third bottom surface. a straight body portion having an inner peripheral wall that defines an axial hole penetrating along an axial direction and an outer peripheral wall that is positioned on either side of a cylindrical internal space that surrounds the inner peripheral wall;
flanges located at both ends of the straight body portion;
and a lid portion attached to at least one of the flange portions,
At least the body portion and the flange portion are made of ceramics,
The cover portion is disk -shaped and has an outer diameter within ±1 mm of the outer diameter of the outer wall. a straight body portion having an inner peripheral wall that defines an axial hole penetrating along an axial direction and an outer peripheral wall that is positioned on either side of a cylindrical internal space that surrounds the inner peripheral wall;
flanges located at both ends of the straight body portion;
and a lid portion attached to at least one of the flange portions,
At least the body portion and the flange portion are made of ceramics,
The outer surface of the lid portion is an extension of the outer surface of the outer wall . a straight body portion having an inner peripheral wall that defines an axial hole penetrating along an axial direction and an outer peripheral wall that is positioned on either side of a cylindrical internal space that surrounds the inner peripheral wall;
and a flange portion located at both ends of the straight body portion and having a through hole connected to the internal space along the axial direction,
the body portion and the flange portion are made of ceramics,
A wire winding bobbin, in which the other of the flange portions and the straight body portion are joined together, and a first joining layer is provided between the main surface of the flange portion on the straight body portion side and the end face of the outer wall on the flange portion side . The wire winding bobbin according to claim 12, wherein the ceramic has a plurality of adjacent closed pores, and the value obtained by subtracting the average value of the circle equivalent diameter of the closed pores from the average value of the distance between the centers of gravity of the closed pores is 4 μm or more and 20 μm or less. the first bonding layer has a first protruding portion connected to the first bonding layer, the first protruding portion being in contact with at least one of an inner peripheral surface and an outer peripheral surface of the outer peripheral wall and the main surface;
the first protrusion and the flange have closed pores,
14. The wire winding bobbin according to claim 12 , wherein an average diameter of closed pores in the first protrusion is 1.5 times or less an average diameter of closed pores in the flange portion. the first bonding layer has a first protruding portion connected to the first bonding layer, the first protruding portion being in contact with at least one of an inner peripheral surface and an outer peripheral surface of the outer peripheral wall and the main surface;
the first protrusion has closed pores,
The wire winding bobbin according to any one of claims 12 to 14 , wherein an average aspect ratio of the closed pores of the first projections is 2 or less. a straight body portion having an inner peripheral wall that defines an axial hole penetrating along an axial direction and an outer peripheral wall that is positioned on either side of a cylindrical internal space that surrounds the inner peripheral wall;
and a flange portion located at both ends of the straight body portion and having a through hole connected to the internal space along the axial direction,
the body portion and the flange portion are made of ceramics,
The other of the flange portions and the straight body portion are joined together, and a second joining layer is provided between a main surface of the flange portion on the straight body portion side and an end surface of the inner circumferential wall on the flange portion side,
the second bonding layer has a second convex portion connected to the second bonding layer, the second convex portion being in contact with at least one of an inner circumferential surface and an outer circumferential surface of the inner circumferential wall and the main surface;
the second protrusion and the flange have closed pores,
a mean diameter of the closed pores of the second convex portion being 1.5 times or less a mean diameter of the closed pores of the flange portion. a straight body portion having an inner peripheral wall that defines an axial hole penetrating along an axial direction and an outer peripheral wall that is positioned on either side of a cylindrical internal space that surrounds the inner peripheral wall;
and a flange portion located at both ends of the straight body portion and having a through hole connected to the internal space along the axial direction,
the body portion and the flange portion are made of ceramics,
The other of the flange portions and the straight body portion are joined together, and a second joining layer is provided between a main surface of the flange portion on the straight body portion side and an end surface of the inner circumferential wall on the flange portion side,
the second bonding layer has a second convex portion connected to the second bonding layer, the second convex portion being in contact with at least one of an inner circumferential surface and an outer circumferential surface of the inner circumferential wall and the main surface;
the second protrusion has closed pores,
a mean aspect ratio of the closed pores of the second protrusions is 2 or less ; A winding device using the wire winding bobbin according to any one of claims 1 to 17 .

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