Coil body, inductive rotational speed sensor, and method for producing the same

An inductive rotational speed sensor, comprising:

• a coil body for an inductive rotational speed sensor, including:
• a pole assembly;
• a base body having at least one winding region, which includes coil windings about an axial axis and an opening that receives along the axial axis the pole assembly, wherein the pole assembly includes a magnet and a pole core in the opening of the base body;
• and
• two current rails, each of current rail of the current rails runs parallel to the axial axis and includes a respective contact region for a respective electrical connection cable to connect at least one coil winding of the coil windings in the at least one winding region to the respective electrical connection cable, wherein each of the current rails is formed from a flat metal sheet and has a main surface, each current rail being bent, about a longitudinal direction, in the respective contact region to form a respective contact surface perpendicular to the main surface;
• wherein each current rail of the two current rails includes a respective connection region and a respective intermediate region, the respective intermediate region being situated between the respective connection region and the respective contact region, the respective connection region being at a first end of the current rail and the respective contact region being at a second end of the current rail, the first and second ends being opposite ends of the current rail relative to each other;
• wherein each of the respective contact regions includes a bendable section in the respective contact surface and is configured to guide the respective electrical connection cable, at least in some sections, (i) parallel to the axial axis for an axial variant or, (ii) perpendicular thereto in a radial manner for a radial variant,
• wherein each bendable section of each of the respective contact regions has a reduced cross-sectional area by way two material cut-outs so that a defined bend of the bendable section can be realized in a manner in which an end section of the respective contact region can be bent about an axis that is perpendicular to the main surface, at the material cut-outs, away from the axial axis and perpendicular to a remaining part of the respective contact region;
• wherein the two current rails are formed identically and fastened to opposite lying sides on the base body;
• a casing, which is made from a synthetic material, that encases at least in part the coil body, which has the coil windings and the pole assembly;
• wherein each respective current rail of the two current rails includes a respective tab fixed to the base body and which by a positive-locking or a non-positive locking fixing arrangement on the base body, the respective tabs prevent an axial displacement of the current rails relative to the base body, and wherein for each respective current rail of the two current rails, the respective tab is formed as a vertically upwards bent section of the respective intermediate section of the respective current rail, and
• wherein each respective current rail of the two current rails is bent in the respective connection region of the respective current rail, toward the respective contact region of the respective current rail, in a U-shape, and a protruding limb of each of the U-shapes has a slit which receives at least one wire of the coil, the protruding limb extending in a direction toward the respective contact region of the respective current rail.

A method for producing two current rails for a coil body, the method comprising:

• producing each current rail of the two current rails by:
• stamping a flat metal sheet to form the current rail, the current rail having a main surface including a contact region, a connection region for at least one coil winding of a plurality of coil windings, and an intermediate region between the contact region and the connection region, the connection region being at a first end of the current rail and the contact region being at a second end of the current rail, the first and second ends being opposite ends of the current rail relative to one another,
• wherein the contact region includes a bendable section and is configured to guide a respective electrical connection cable, at least in some sections, (i) parallel to an axial axis for an axial variant, or, (ii) perpendicular thereto, in a radial manner for a radial variant,
• wherein the bendable section has a reduced cross-sectional area by way of two material cut-outs so that a defined bend of the bendable section can be realized in a manner in which an end section of the contact region can be bent about an axis perpendicular to the main surface, at the material cut-outs, away from the axial axis and perpendicular to a remaining part of the contact region;
• forming a slit in the connection region for the at least one coil wire;
• bending the connection region toward the contact region to form a U-shaped end section having the slit in a protruding limb, the protruding limb extending in a direction toward the contact region;
• bending the contact region about a longitudinal direction to form a contact surface perpendicular to the main surface, wherein the bendable section is in the contact surface;
• wherein the coil body includes:
• a base body having at least one winding region for the coil windings about the axial axis, and an opening for receiving a pole assembly along the axial axis;
• and
• the two current rails run parallel to the axial axis, and the contact regions electrically connecting the respective electrical connection cables to the coil windings in the winding region;
• wherein each respective current rail of the two current rails includes a respective tab fixed to the base body and which by a positive-locking or a non-positive locking fixing arrangement on the base body, the respective tabs prevent an axial displacement of the current rails relative to the base body, and wherein for each respective current rail of the two current rails, the respective tab of the respective current rail is formed as a vertically upwards bent section of the intermediate section of the respective current rail.

A method for producing a coil body for an inductive rotational speed sensor, the method comprising:

• providing a base body that includes at least one winding region for coil windings about an axial axis and an opening for receiving a pole assembly along the axial axis;
• and
• attaching two current rails that each run parallel to the axial axis and each include a respective contact region for a respective electrical connection cable to connect at least one coil winding of the coil windings in the at least one winding region to the respective electrical connection cable, wherein each of the current rails is formed from a flat metal sheet and has a main surface, each current rail being bent, about a longitudinal direction, in the respective contact region to form a respective contact surface perpendicular to the main surface;
• wherein each current rail of the two current rails includes a respective connection region and a respective intermediate region, the respective intermediate region being situated between the respective connection region and the respective contact region, the respective connection region being at a first end of the current rail and the respective contact region being at a second end of the current rail, the first and second ends being opposite ends of the current rail relative to each other;
• wherein for each of the two current rails, the respective contact region extends along the axial axis, and
• wherein each of the respective contact regions includes at least one bendable section in the respective contact surface and is configured to guide the respective electrical connection cable at least in some sections, (i) parallel to the axial axis for an axial variant, or (ii) perpendicular thereto in a radial manner for a radial variant,
• wherein each bendable section of each of the respective contact regions has a reduced cross-sectional area by way of two material cut-outs so that a defined bend of the bendable section can be realized in a manner in which an end section of the respective contact region can be bent about an axis that is perpendicular to the main surface, at the material cutouts, away from the axial axis and perpendicular to a remaining part of the respective contact region, and
• wherein each respective current rail of the two current rails includes a respective tab fixed to the base body and which by a positive-locking or a non-positive locking fixing arrangement on the base body, the respective tabs prevent an axial displacement of the current rails relative to the base body, and wherein for each respective current rail of the two current rails, the respective tab of the respective current rail is formed as a vertically upwards bent section of the respective intermediate section of the respective current rail, and
• wherein each respective current rail of the two current rails is bent in the respective connection region of the respective current rail, toward the respective contact region of the respective current rail, in a U-shape, and a protruding limb of each of the U-shapes has a slit which receives at least one wire of the coil, the protruding limb extending in a direction toward the respective contact region of the respective current rail.