The present invention relates to a coil device used as, for example, an inductor.
As a coil device known as an inductor or the like, for example, a coil device described in Japanese Patent Laid-Open No. 2018-133402 (Patent Literature 1) is known. The coil device described in Patent Literature 1 includes an element body, a coil disposed inside the element body, and a terminal connected to a lead portion of the coil. The terminal includes a wire connecting portion connected to the lead portion of the coil, and a base portion (coil fixing portion) that holds the wire connecting portion. The base portion is disposed inside the element body, and the coil can be disposed on an upper surface of the base portion.
The coil device described above is obtained by disposing a coil and a terminal inside a mold, filling the mold with a magnetic material that constitutes the element body, and performing compression molding. As described above, by disposing the coil on the upper surface of the base portion, there is an advantage that the coil can be prevented from being displaced due to applied pressure during the compression molding.
However, when the coil is disposed on the upper surface of the base portion, the following problem may occur. That is, although a conductor portion of the coil is normally covered with an insulation coating, damage to the insulation coating may expose the conductor portion of the coil. In this case, the base portion and the exposed conductor portion of the coil come into contact with each other either directly or via plating or metal powder of the element body on a surface of the base portion, thereby causing a short circuit between the conductor portion of the coil and the terminal.
Therefore, in order to avoid such a problem, instead of disposing the coil on the upper surface of the base portion, for example, it is conceivable to dispose the coil at a position spaced upward from the upper surface of the base portion, so as to forcibly avoid physical contact between the upper surface of the base portion and a bottom surface of the coil. However, in this case, since the coil is disposed far from the terminal (particularly, the wire connecting portion), processing such as bending the lead portion is required in order to pull out the lead portion of the coil to the position of the wire connecting portion of the terminal. Such processing is not preferable since it causes an increase in man-hours and a deterioration in quality of the coil device.
The present invention is made in view of such circumstances, and an object thereof is to provide a coil device that prevents occurrence of short circuits and contributes to reducing man-hours and improving quality.
In order to achieve the above object, a coil device according to the present invention includes:
a coil;
a terminal including a wire connecting portion connected to a lead portion of the coil, and a base portion positioned at substantially the same height as a bottom surface of the coil and holding the wire connecting portion; and
an element body covering the coil together with the wire connecting portion and the base portion, in which
the base portion includes a main branch portion and a sub branch portion, and a curved portion curved along an outer peripheral surface of the coil is formed at a position spaced apart from the outer peripheral surface of the coil on an inner edge of each of the main branch portion and the sub branch portion.
In the coil device according to the present invention, since the base portion is positioned at substantially the same height as a bottom surface of the coil, the lead portion of the coil can be led out to the position of the wire connecting portion and connected thereto without being bent unnecessarily. Therefore, it is possible to prevent damage to the lead portion of the coil and obtain a high-quality coil device. Unnecessary processing (bending) of the coil can be avoided, and the number of man-hours can be reduced.
Since the inner edges (curved portions) of the main branch portion and the sub branch portion are disposed away from the outer peripheral surface of the coil, the main branch and the sub-branch do not come into physical contact with the coil, and it is possible to ensure a sufficient withstand voltage therebetween. Therefore, it is possible to avoid the above problem in the related art (the problem that the conductor portion of the coil and the terminal physically come into contact with each other due to damage to the insulation coating of the coil, thereby causing a short circuit therebetween).
Since the inner edges (curved portions) of the main branch portion and the sub branch portion are curved along the outer peripheral surface of the coil, it is possible to dispose the main branch portion, the sub branch portion, and the wire connecting portion relatively close to the outer peripheral surface of the coil, and it is possible to make the base portion or the wire connecting portion compact. A volume of the coil can be increased by the amount of compactness of the base portion or the wire connecting portion, thereby improving inductance characteristics of the coil device.
Preferably, the main branch portion includes a main protruding portion that protrudes forward of the element body, the sub branch portion includes a sub protruding portion that protrudes rearward of the element body, and one of the main protruding portion and the sub protruding portion is displaced relative to the other of the main protruding portion and the sub protruding portion along a left-right direction perpendicular to a front-rear direction of the element body. By adopting such a configuration, the terminal can be prevented from coming off from the element body and displacement of the base portion in the element body can be prevented particularly in the left-right direction of the element body by an anchoring effect of the main protruding portion and the sub protruding portion. By displacing one of the main protruding portion and the sub protruding portion relative to the other along the left-right direction of the element body, an area occupied by the main protruding portion and the sub protruding portion inside the element body can be sufficiently ensured, so that the above effect can be effectively obtained.
Preferably, an outer edge of the main branch portion is curved forward from a side of the element body inside the element body, an outer edge of the sub branch portion is curved rearward from a side of the element body inside the element body, and a radius of curvature of the outer edge of the main branch portion is different from a radius of curvature of the outer edge of the sub branch portion. By adopting such a configuration, the terminal can be prevented from coming off from the element body and displacement of the base portion in the element body can be prevented particularly in the left-right direction of the element body by an anchoring effect of the main branch portion and the sub branch portion. By making the radius of curvature of the outer edge of the main branch portion different from the radius of curvature of the outer edge of the sub branch portion, the main branch portion or the sub branch portion may be provided with a sufficient size to achieve the above effect, so that the above effect can be effectively obtained.
Preferably, the terminal includes a first terminal and a second terminal,
the first terminal includes a first base portion,
the second terminal includes a second base portion,
the first base portion includes a first main branch portion and a first sub branch portion,
the second base portion includes a second main branch portion and a second sub branch portion,
the curved portion includes a first main curved portion formed on an inner edge of the first main branch portion, a first sub curved portion formed on an inner edge of the first sub branch portion, a second main curved portion formed on an inner edge of the second main branch portion, and a second sub curved portion formed on an inner edge of the second sub branch portion, and
a center position of a virtual circle defined by the first main curved portion, the first sub curved portion, the second main curved portion, and the second sub curved portion substantially coincides with a center position of an inner periphery of the coil.
By adopting such a configuration, it is possible to make a clearance between the outer peripheral surface of the coil and the inner edges of the first base portion (the first main branch portion and the first sub branch portion) substantially constant, and to make a clearance between the outer peripheral surface of the coil and the inner edges of the second base portion (the second main branch portion and the second sub branch portion) substantially constant. Therefore, it is possible to prevent variations in inductance characteristics from occurring for each product. It is also possible to prevent local formation of regions with low withstand voltage between the first base portion and the second base portion and the coil, thereby promoting quality improvement of the coil device.
Preferably, an upper surface of the base portion and the bottom surface of the coil are positioned substantially on the same plane, and a distance between the first main curved portion and the outer peripheral surface of the coil, a distance between the first sub curved portion and the outer peripheral surface of the coil, a distance between the second main curved portion and the outer peripheral surface of the coil, and a distance between the second sub curved portion and the outer peripheral surface of the coil, on the substantially same plane, are substantially equal to one another. When the upper surface of the base portion and the bottom surface of the coil are positioned substantially on the same plane, the lead portion of the coil can be led out to the position of the wire connecting portion and connected thereto without being bent unnecessarily. This point is particularly advantageous in a case where the coil is formed by a flat wire or the like, which is not easy to process, and contributes to the quality improvement of the coil device. By adopting such a configuration, it is possible to maintain a substantially constant clearance between the outer peripheral surface of the coil and the inner edges of the first base portion and the second base portion (first main curved portion, first sub curved portion, second main curved portion, and second sub curved portion), thereby further improving the quality of the coil device.
Preferably, a part of the wire connecting portion is disposed at a position spaced upward from an upper surface of the base portion. By adopting such a configuration, when the lead portion of the coil is led out at a position spaced upward from the upper surface of the base portion, the lead portion of the coil can be led out to the position of the wire connecting portion and connected thereto without being bent unnecessarily.
Preferably, a center position of the coil is displaced to a side opposite to the wire connecting portion relative to a center of the element body along a front-rear direction of the element body. By adopting such a configuration, it is possible to ensure a sufficient volume of the element body in front of the element body (on a side where the wire connecting portion is disposed). Therefore, it is possible to cover the wire connecting portion and the lead portion of the coil connected thereto with a sufficient amount of the element body and protect the wire connecting portion and the lead portion with the element body. Since a sufficient space is formed in front of the element body for disposing the wire connecting portion, there is no need to expand the element body outward (forward) to ensure the space, and it is possible to reduce a size of the coil device.
Preferably, the coil is made of a flat wire. By adopting such a configuration, a relatively large current can flow through the coil, deformation of the coil is unlikely to occur, and a high-quality coil device can be obtained.
Hereinafter, the present invention will be described based on embodiments shown in the drawings.
As shown in
As shown in
In the following description, for ease of understanding, the upper side of the paper surface (the negative side of the Z-axis direction in
Although dimensions of the inductor 1 are not particularly limited, a width thereof in the X-axis direction is preferably 2 to 20 mm, a width thereof in the Y-axis direction is preferably 2 to 20 mm, and a width thereof in the Z-axis direction is preferably 1 to 10 mm.
The core 8 is made of a mixture containing magnetic powder and binder resin, and is formed by combining a first core 5 and a second core 6 shown in
The core 8 (the first core 5 and/or the second core 6) is made of synthetic resin in which ferrite particles or metal magnetic particles are dispersed. However, a material constituting the core 8 is not limited thereto, and the core 8 may be constituted by a synthetic resin that does not contain these particles. Examples of the ferrite particles include Ni—Zn ferrite and Mn—Zn ferrite. The metal magnetic particles are not particularly limited, and examples thereof include Fe—Ni alloy powder, Fe—Si alloy powder, Fe—Si—Cr alloy powder, Fe—Co alloy powder, Fe—Si—Al alloy powder, and amorphous iron.
The synthetic resin contained in the core 8 is not particularly limited, and preferable examples thereof include epoxy resin, phenol resin, polyester resin, polyurethane resin, polyimide resin, and silicone resin.
As shown in
A winding axis direction of the coil 2 corresponds to the Z-axis direction. The wire 3 is wound such that two relatively wide surfaces among four side surfaces constituting an outer surface of the flat wire face inner and outer peripheral sides of the coil 2. Note that the wire 3 may be wound such that two relatively narrow surfaces among the four side surfaces constituting the outer surface of the flat wire face the inner and outer peripheral sides of the coil 2, so as to form the coil 2, which is an edgewise coil.
The coil 2 is an air-cored coil, and as shown in
Examples of a material constituting the wire 3 include a good conductor of metal such as copper, copper alloys, silver, and nickel, but the material is not particularly limited as long as it is a conductive material. The wire 3 is an insulated coated wire, and an insulation coating 30 is formed on a surface of the wire 3. Resin constituting the insulation coating 30 is not particularly limited, but for example, a polyamide-imide resin, a urethane resin, or the like is used. As the wire 3, a self-welding wire including a welding coating outside the insulation coating may be used. Although the resin constituting the welding coating is not particularly limited, for example, a polyamide resin, an epoxy resin, or the like is used. The insulation coating 30 is removed from the wire 3 at positions of the lead portions 3a, 3b in order to establish electrical connection with the terminals 4a, 4b.
As shown in
In the state shown in
As shown in
As shown in
As shown in
The wire connecting portion 42a is connected to an end portion of the main branch portion 410a (more specifically, a main protruding portion 412a, which will be described later) on the positive side of the Y-axis direction, and the main branch portion 410a holds the wire connecting portion 42a. End portions of the main branch portion 410a and the sub branch portion 411a on the negative side of the X-axis direction are both connected to a lower end portion of the connecting portion 43a. The main branch portion 410a extends further outward in the Y-axis direction than an end portion of the connecting portion 43a on the positive side of the Y-axis direction, and the sub branch portion 411a extends further outward in the Y-axis direction than an end portion of the connecting portion 43a on the negative side of the Y-axis direction.
A groove portion 45a is formed between the main branch portion 410a and the sub branch portion 411a. The groove portion 45a forms a gap between the main branch portion 410a and the sub branch portion 411a so that the base portion 41a has a bifurcated shape.
The main branch portion 410a is positioned on the positive side of the Y-axis direction of the groove portion 45a, and the sub branch portion 411a is positioned on the negative side of the Y-axis direction of the groove portion 45a. Each of the main branch portion 410a and the sub branch portion 411a is bent in a substantially L shape as a whole. That is, the main branch portion 410a extends inward in the X-axis direction from a lower end portion of the connecting portion 43a, turns to the Y-axis direction, and extends toward the positive side of the Y-axis direction. The sub branch portion 411a extends inward in the X-axis direction from the lower end portion of the connecting portion 43a, turns to the Y-axis direction, and extends toward the negative side of the Y-axis direction.
As shown in
An outer edge 410a1 of the main branch portion 410a is smoothly curved forward from the side of the core 8 in line with an overall shape of the main branch portion 410a. An outer edge 411a1 of the sub branch portion 411a is smoothly curved rearward from the side of the core 8 in line with an overall shape of the sub branch portion 411a. A radius of curvature R1 of the outer edge 410a1 of the main branch portion 410a is different from a radius of curvature R2 of the outer edge 411a1 of the sub branch portion 411a. In the present embodiment, R1>R2, but R1<R2 is also possible.
By curving the outer edge 410a1 of the main branch portion 410a and the outer edge 411a1 of the sub branch portion 411a, the terminal 4a can be prevented from coming off from the core 8 and displacement of the base portion 41a in the core 8 can be prevented particularly in the left-right direction of the core 8 by an anchoring effect of the main branch portion 410a and the sub branch portion 411a. By making the radius of curvature of the outer edge 410a1 of the main branch portion 410a different from the radius of curvature of the outer edge 411a1 of the sub branch portion 411a, the main branch portion 410a and the sub branch portion 411a may be provided with a sufficient size to achieve the above effect, so that the above effect can be effectively obtained.
The main branch portion 410a includes the main protruding portion 412a that protrudes (extends) forward of the core 8. The sub branch portion 411a includes a sub protruding portion 413a that protrudes (extends) rearward of the core 8. The main branch portion 410b includes a main protruding portion 412b that protrudes forward of the core 8. The sub branch portion 411b includes a sub protruding portion 413b that protrudes rearward of the core 8.
The main protruding portion 412a is formed narrower than other portions of the main branch portion 410a, and the sub protruding portion 413a is formed narrower than other portions of the sub branch portion 411a. The sub branch portion 411a is formed narrower in the X-axis direction than the main branch portion 410a.
The main protruding portion 412a protrudes forward of the core 8 from the outer peripheral surface 2e of the coil 2 along the Y-axis direction. On the other hand, the sub protruding portion 413a protrudes rearward of the core 8 from an inner peripheral surface 2f of the coil 2 along the Y-axis direction, while does not protrude rearward of the core 8 from the outer peripheral surface 2e of the coil 2. That is, an end portion of the sub protruding portion 413a in the Y-axis direction is disposed between the inner peripheral surface 2f and the outer peripheral surface 2e of the coil 2 in the Y-axis direction.
One of the main protruding portion 412a and the sub protruding portion 413a is displaced with respect to the other along the X-axis direction of the core 8. In the present embodiment, the sub protruding portion 413a is displaced to the outside of the core 8 in the X-axis direction with respect to the main protruding portion 412a. That is, an inner edge of the sub protruding portion 413a is positioned more outside the core 8 than an inner edge of the main protruding portion 412a, and an outer edge of the sub protruding portion 413a is positioned more outside the core 8 than an outer edge of the main protruding portion 412a.
By providing the base portion 41a with the main protruding portion 412a and the sub protruding portion 413a, the terminal 4a can be prevented from coming off from the core 8 and displacement of the base portion 41a in the core 8 can be prevented particularly in the left-right direction of the core 8 by an anchoring effect of the main protruding portion 412a and the sub protruding portion 413a. By displacing one of the main protruding portion 412a and the sub protruding portion 413a relative to the other along the left-right direction of the core 8, an area occupied by the main protruding portion 412a and the sub protruding portion 413a inside the core 8 can be sufficiently ensured, so that the above effect can be effectively obtained.
As shown in
The main curved portions 414a, 414b are mainly formed on parts of the main branch portions 410a, 410b excluding the main protruding portions 412a, 412b. The sub curved portions 415a, 415b are mainly formed on parts of the sub branch portions 411a, 411b excluding the sub protruding portions 413a, 413b.
A radius of curvature of the main curved portion 414a, a radius of curvature of the sub curved portion 415a, a radius of curvature of the main curved portion 414b, and a radius of curvature of the sub curved portion 415b are substantially equal to each other. These radiuses of curvature are approximately equal to a radius of curvature of an outer periphery (outer peripheral surface 2e) or an inner periphery (inner peripheral surface 2f) of the coil 2. Therefore, the main curved portions 414a, 414b and the sub curved portions 415a, 415b are curved along the outer peripheral surface 2e of the coil 2 at positions spaced from the outer peripheral surface 2e of the coil 2 by a predetermined distance.
As shown in
A center position of a virtual circle C defined by the main curved portion 414a, the sub curved portion 415a, the main curved portion 414b, and the sub curved portion 415b approximately coincides with a center position of the inner periphery (inner peripheral surface 2f) or the outer periphery (outer peripheral surface 2e) of the coil 2. That is, the virtual circle C and a virtual circle defined by the inner periphery (inner peripheral surface 2f) or the outer periphery (outer peripheral surface 2e) of the coil 2 are arranged concentrically.
As shown in
The inner edge 410b2 of the main branch portion 410b is positioned outside an inner side surface 3b2 of the lead portion 3b in the X-axis direction. Although detailed illustration is omitted, the inner edge 411b2 (
A lead bottom portion 3b1 of the lead portion 3b led from a lower part (second lead-out position 2d) of the coil 2 is placed on an upper surface of the main branch portion 410b between the main branch portion 410a and the main branch portion 410b. As a result, the lead portion 3b is fixed to the main branch portion 410b, and during manufacture of the inductor 1 (during compression molding of the first core 5 and the second core 6 shown in
As shown in
The wire connecting portions 42a, 42b have a flat plate shape substantially parallel to an XZ plane, and are arranged substantially orthogonal to the lead portions 3a, 3b (see
As shown in
As shown in
The length of the wire connecting portion 42b in the Z-axis direction is smaller than the length of the wire 3 in the Z-axis direction, and the upper end portion of the wire connecting portion 42b is disposed at a position corresponding to the first layer of the coil 2 (second lead-out position 2d). Therefore, the position of the upper end portion of the wire connecting portion 42a and the position of the upper end portion of the wire connecting portion 42b are displaced from each other along the Z-axis direction.
In this way, since the positions (heights) of the wire connecting portions 42a, 42b are adjusted to match positions (heights) of the lead-out positions 2c, 2d, the lead portions 3a, 3b can be led out to the positions of the wire connecting portions 42a, 42b and connected thereto without being bent unnecessarily.
As shown in
It is possible to dispose the outer peripheral surface 2e of the coil 2 at a position sufficiently spaced from a side surface of the core 8 on the positive side of the Y-axis direction, ensure a sufficient thickness of the core 8 between the outer peripheral surface 2e of the coil 2 and the side surface of the core 8 on the positive side of the Y-axis direction, and prevent cracks from occurring on the side surface of the core 8 on the positive side of the Y-axis direction.
As shown in
A notch portion 420a is formed along the Z-axis direction in an inner edge of the wire connecting portion 42a between the wire connecting portion 42a and the wire connecting portion 42b. The notch portion 420a is cut downward at a predetermined depth from an upper end of the wire connecting portion 42a. The lead portion 3a of the wire 3 can be fixed to the notch portion 420a.
A length of the notch portion 420a in the Z-axis direction is substantially the same as the length of the wire 3 in the Z-axis direction. As shown in
In this way, by fixing the lead portion 3a at a position spaced upward from the notch bottom portion 421a, even if the first lead-out position 2c of the lead portion 3a changes along the Z-axis direction, the lead portion 3a does not come into contact with the notch bottom portion 421a, and the lead portion 3a can be reliably fixed to the notch portion 420a. When connecting the lead portion 3a to the wire connecting portion 42a, the lead portion 3a can be fixed to the notch portion 420a in a state of being straightly led out without being bent.
Note that an upper end portion of the lead portion 3b also protrudes above the upper end of the wire connecting portion 42b, similarly to the upper end portion of the lead portion 3a. This is because the length of the wire connecting portion 42b in the Z-axis direction is smaller than the length of the wire 3 in the Z-axis direction due to the miniaturization of the wire connecting portion 42b.
An outer side surface 3a3 (more specifically, a part or most of the outer side surface 3a3) of the lead portion 3a is connected to the inner edge of the wire connecting portion 42a, and an outer side surface 3b3 (more specifically, a part or most of the outer side surface 3a3) of the lead portion 3b is connected to an inner edge of the wire connecting portion 42b. The inner side surface 3a2 of the lead portion 3a is not fixed to the wire connecting portion 42a, and the inner side surface 3b2 of the lead portion 3b is not fixed to the wire connecting portion 42b.
With respect to the X-axis direction, a position of the outer side surface 3a3 of the lead portion 3a is positioned more inside than a position of the outer peripheral surface 2e of the coil 2 at the first lead-out position 2c. Therefore, with respect to the X-axis direction, the inner edge of the wire connecting portion 42a is positioned between the outer side surface 3a3 of the lead portion 3a and the outer peripheral surface 2e at the first lead-out position 2c. With respect to the X-axis direction, the position of the outer side surface 3b3 of the lead portion 3b is positioned more inside than the position of the outer peripheral surface 2e of the coil 2 at the second lead-out position 2d. Therefore, the inner edge of the wire connecting portion 42b is positioned between the outer side surface 3b3 of the lead portion 3b and the outer peripheral surface 2e at the second lead-out position 2d with respect to the X-axis direction.
In the present embodiment, the wire connecting portion 42a is positioned biased outward of the lead portion 3a that is led out forward of the core 8 in the X-axis direction. Similarly, the wire connecting portion 42b is positioned biased outward of the lead portion 3b that is led out forward of the core 8 in the X-axis direction. More specifically, the inner edge of the wire connecting portion 42a is positioned outside the inner side surface 3a2 of the lead portion 3a in the X-axis direction. The inner edge of the wire connecting portion 42a is positioned outside the outer side surface 3a3 of the lead portion 3a in the X-axis direction at the position of the notch portion 420a. The inner edge of the wire connecting portion 42b is positioned outside the inner side surface 3b2 and the outer side surface 3b3 of the lead portion 3b in the X-axis direction. That is, the wire connecting portions 42a, 42b do not protrude inward in the X-axis direction beyond the inner side surfaces 3a2, 3b2 of the lead portions 3a, 3b, and the entire wire connecting portions 42a, 42b are arranged outside the inner side surfaces 3a2, 3b2 in the X-axis direction.
As shown in
As shown in
As shown in
The mounting portions 44a, 44b are connected to a circuit board or the like via a connection member such as solder or a conductive adhesive. In this case, solder fillets can be formed in the connecting portions 43a, 43b, so that a mounting strength of the inductor 1 on the circuit board or the like can be increased.
Next, a method for manufacturing the inductor 1 will be described with reference to
Next, as shown in
When disposing the coil 2, the outer surface 3a3 of the lead portion 3a of the wire 3 is fixed to the inner edge (notch portion 420a) of the wire connecting portion 42a, and the wire connecting portion 42a is arranged outside the outer side surface 3a3 in the X-axis direction. The outer side surface 3b3 of the lead portion 3b of the wire 3 is fixed to the inner edge of the wire connecting portion 42b, and the wire connecting portion 42b is disposed outside the outer side surface 3b3 in the X-axis direction. The lead portion 3b of the wire 3 is placed on the main branch portion 410b so that the lead bottom portion 3b1 contacts the upper surface of the main branch portion 410b.
Next, as shown in
Next, the coil 2 in which the terminals 4a, 4b are fixed to each end portion respectively is disposed inside the mold, and the coil 2 is combined with the first core 5 and the second core 6 as shown in
The first core 5 and the second core 6 of the temporary assembly shown in
Next, as shown in
As shown in
As shown in
Since the main curved portions 414a, 414b of the main branch portions 410a, 410b and the sub curved portions 415a, 415b of the sub branch portions 411a, 411b are curved along the outer peripheral surface 2e of the coil 2, it is possible to dispose the main branch portions 410a, 410b, the sub branch portions 411a, 411b, and further the wire connecting portions 42a, 42b relatively close to the outer peripheral surface 2e of the coil 2, and it is possible to make the base portions 41a, 41b or the wire connecting portions 42a, 42b compact. A volume of the coil 2 can be increased by the amount of compactness of the base portions 41a, 41b or the wire connecting portions 42a, 42b, thereby improving inductance characteristics of the inductor 1.
The center position of the virtual circle C defined by the main curved portion 414a, the sub curved portion 415a, the main curved portion 414b, and the sub curved portion 415b approximately coincides with a position of a center O of the inner periphery of the coil 2. Therefore, a clearance between the outer peripheral surface 2e of the coil 2 and the inner edges of the main branch portions 410a, 410b and the sub branch portions 411a, 411b can be made substantially constant. Therefore, it is possible to prevent variations in the inductance characteristics from occurring for each product. It is also possible to prevent local formation of regions with low withstand voltage between the base portions 41a, 41b and the coil 2, thereby promoting quality improvement of the inductor 1.
The upper surfaces of the base portions 41a, 41b and the bottom surface 2b of the coil 2 are positioned substantially on the same plane, and the distances D1 to D4 shown in
An inductor 1A according to a second embodiment of the present invention shown in
As shown in
The pair of protruding portions 423a are formed on one side and the other side in the X-axis direction with the accommodating portion 422a interposed therebetween. The pair of protruding portions 423a can prevent the lead portion 3a accommodated in the accommodating portion 422a from being displaced inward and outward in the X-axis direction.
The wire connecting portion 42bA has a bifurcated shape, and includes an accommodating portion 422b and a pair of protruding portions 423b. The accommodating portion 422b is a groove opened upward, and is cut downward along the Z-axis direction from an upper end of the wire connecting portion 42bA. Unlike the accommodating portion 422a, the accommodating portion 422b extends to the base portion 41b (the main branch portion 410b). In other words, the accommodating portion 422b is formed not only at the wire connecting portion 42bA but also at the end portion of the base portion 41b (main branch portion 410b) in the Y-axis direction. By adopting such a configuration, when processing the terminal 4bA, it becomes easy to bend the pair of protruding portions 423b in a substantially vertical direction with respect to the base portion 41b, thereby facilitating the processing of the terminal 4bA.
The lead portion 3b of the wire 3 can be slid and accommodated from above the wire connecting portion 42bA inside the accommodating portion 422b. However, the lead portion 3b is not accommodated in a part of the accommodating portion 422b extending to the end portion of the base portion 41b in the Y-axis direction. A length of the accommodating portion 422b in the Z-axis direction is smaller than a length of the lead portion 3b in the Z-axis direction. Therefore, an upper end portion of the lead portion 3b protrudes from above the accommodating portion 422b. As in the first embodiment, the lead portion 3b is accommodated in the accommodating portion 422b so that the lead bottom portion 3b1 contacts the upper surface of the base portion 41b.
The pair of protruding portions 423b are formed on one side and the other side in the X-axis direction with the accommodating portion 422b interposed therebetween. The pair of protruding portions 423b are arranged substantially parallel to the pair of protruding portions 423a.
The present embodiment also has the same effect as the first embodiment. In the present embodiment, since the accommodating portions 422a, 422b are formed in the terminals 4aA, 4bA, the accommodating portions 422a, 422b prevent the lead portions 3a, 3b from being displaced in the X-axis direction, and the lead portions 3a, 3b can be firmly fixed to the wire connecting portions 42aA, 42bA.
Note that the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention.
In each of the above-described embodiments, application examples of the present invention to inductors have been shown, but the present invention may be applied to coil devices other than inductors.
In each of the above embodiments, the wire 3 is made of a flat wire, but may be made of a wire other than a flat wire such as a round wire or a square wire.
In each of the above-described embodiments, the wire 3 is wound in a circular spiral shape, but it may be in an elliptical spiral shape, an angular spiral shape, or the like.
In each of the above embodiments, the core 8 is constituted by two cores, the first core 5 and the second core 6, but the core 8 of the inductor 1 may be constituted by only one core. In this case, the core 8 may be formed inside the mold by compaction molding, injection molding, or the like.
As shown in
Number | Date | Country | Kind |
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2021-188783 | Nov 2021 | JP | national |