Sensor for a high-pressure line, and method for producing same

A sensor for a high-pressure line comprising:

• an outer tube of metal with an outer surface, an inner surface, an outer diameter and an inner diameter, and an inner tube of metal with an outer surface, an inner surface, an outer diameter and an inner diameter, wherein the inner tube extends concentrically in the outer tube such that the inner tube and the outer tube together form a tube, and wherein the overall wall thickness measured as half of the difference between the outer diameter of the outer tube and the inner diameter of the inner tube is equal to or larger than the inner diameter of the inner tube;
• at least one groove extending in a longitudinal direction of the tube in the inner surface of the outer tube or in the outer surface of the inner tube;
• at least one signal line placed in the groove;
• and
• at least one pick-up element connected to the signal line,
• wherein the pick-up element is placed at least in the groove or in at least one recess provided in addition to the groove at least in the outer surface of the inner tube or in the inner surface of the outer tube,
• wherein the outer tube is in a frictional connection with the inner tube, and
• wherein the inner tube has a larger elongation than the outer tube.

A method for manufacturing a sensor for a high-pressure line comprising the steps:

• providing an outer tube of metal with an outer surface, an inner surface, an outer diameter and an inner diameter;
• providing an inner tube of metal with an outer surface, an inner surface, an outer diameter and an inner diameter, wherein the outer diameter of the inner tube is smaller than the inner diameter of the outer tube, and wherein the overall wall thickness measured as a half of a difference between the outer diameter of the outer tube and the inner diameter of the inner tube is equal to or larger than the inner diameter of the inner tube;
• providing at least one groove extending in a longitudinal direction of the outer tube or of the inner tube into at least the inner surface of the outer tube or into the outer surface of the inner tube;
• placing at least one signal line in the groove;
• placing at least one pick-up element connected to the signal line at least in the groove or in at least one recess provided at least in the outer surface of the inner tube or in the inner surface of the outer tube;
• inserting the inner tube into the outer tube such that the inner tube extends in the outer tube;
• and
• drawing the inner tube and the outer tube together through a first drawing die having an inner tool surface forming the outer surface of the outer tube,
• wherein a tool diameter of the inner tool surface of the first drawing die is selected such that the by drawing the inner diameter of the outer tube is reduced such that after the drawing the outer tube is in frictional connection with the inner tube.