Heater for electronic thermostat and method for manufacturing the same
Disclosed is a heater for an electronic thermostat, in which response is improved so that time taken in increasing a heating temperature up to a target temperature can be reduced, and an effect on improving fuel efficiency of a vehicle is maximized through effective temperature control of a coolant, and a method of manufacturing the same. Further, there is provided a heater for an electronic thermostat, which is structurally simple, is improved in workability and productivity for mass production when manufactured and assembled, reduces production costs, and enhances durability and reliability when applied to the thermostat for controlling a temperature of a coolant, and a method of manufacturing the same.
1. A heater for an electronic thermostat, comprising:
a tube which comprises a hollow structure of which one end is opened and the other end is closed;
a first lead line which comprises a first end portion exposed to an outside of the tube and a second end portion placed inside the tube and receives electric power from an exterior through the first end portion exposed to the outside of the tube;
a second lead line which comprises a first end portion exposed to the outside of the tube and a second end portion placed inside the tube and is installed to be spaced apart from the first lead line;
a heating coil which is disposed in the tube and electrically connects the first lead line and the second lead line to generate heat based on electrical resistance;
an insulation material which is filled in the tube;
a packing which is installed inside a mouth of the tube and made of an insulating substance serving as a support for supporting and maintaining the first lead line and the second lead line to be spaced apart from each other;
an insulation pipe which is disposed in an inner space formed by the tube and the packing and encloses the first and second lead lines for securing insulation around the first and second lead lines placed inside the tube; and
an insulation ring for securing insulation between the heating coil inside the tube and a closed end portion of the tube,
wherein the insulation pipe encloses the first and second lead lines and the heating coil that are disposed within the tube.
2. The heater for the electronic thermostat according to claim 1 , wherein the heating coil comprises a first end connected to a front end portion of the first lead line inside the tube and a second end connected to a front end portion of the second lead line inside the tube, and is shaped like a ‘U’-shape.
3. The heater for the electronic thermostat according to claim 2 , wherein the connection between the first end of the heating coil and the front end portion of the first lead line inside the tube, and the connection between the second end of the heating coil and the front end portion of the second lead line inside the tube are achieved by respectively inserting the first lead line and the second lead line in both ends of the heating coil, and applying electric resistance welding or laser welding to the inserted portions.
4. The heater for the electronic thermostat according to claim 3 , wherein the first lead line and the second lead line placed inside the tube are configured to have the same length.
5. The heater for the electronic thermostat according to claim 1 , further comprising a fitting which is formed with a screw thread on an outer circumference thereof and put on the outside of the tube through press-fitting so that the heater can be screw-coupled to the heater mounting portion.
6. The heater for the electronic thermostat according to claim 5 , further comprising a cap which is made of an insulating substance and provided in a mouth portion of the fitting so as to close the mouth portion of the fitting while supporting portions of the first and second lead lines exposed to the outside of the tube.
7. The heater for the electronic thermostat according to claim 1 , wherein the insulation pipe encloses portions of the first and second lead lines that extend into the inner space beyond the packing.
8. The heater for the electronic thermostat according to claim 1 , wherein the insulation pipe is disposed in an inner space of the tube closed by the packing and encloses the first and second lead lines.
9. A method of manufacturing a heater for an electronic thermostat, the method comprising:
preparing a tube comprising a hollow structure of which one end is opened and the other end is closed;
preparing a first lead line and a second lead line to be inserted in the tube;
preparing a ‘U’-shaped heating coil bent with respect to a middle of a coil spring;
connecting a first end of the ‘U’-shaped heating coil with the first lead line and a second end of the heating coil with the second lead line;
installing an insulation pipe to enclose the first and second lead lines and the heating coil for securing insulation;
inserting the heating coil, the first and second lead lines connected to the heating coil, and the insulation pipe in the tube;
filling the tube with an insulation material;
installing packing made of an insulating substance at an opened mouth of the tube; and
inserting an insulation ring having an opening before the inserting the heating coil, the first and second lead lines, and the insulation pipe,
wherein the opening of the insulation ring passes through a body of the insulation ring, and
wherein the opening of the insulation ring is filled with the insulation material after filling the tube with the insulation material.
10. A heater for an electronic thermostat, comprising:
a tube which comprises a hollow structure of which one end is opened and the other end is closed;
a first lead line which comprises a first end portion exposed to an outside of the tube and a second end portion placed inside the tube and receives electric power from an exterior through the first end portion exposed to the outside of the tube;
a second lead line which comprises a first end portion exposed to the outside of the tube and a second end portion placed inside the tube and is installed to be spaced apart from the first lead line;
a heating coil which is disposed in the tube and electrically connects the first lead line and the second lead line to generate heat based on electrical resistance;
an insulation material which is filled in the tube;
a packing which is installed inside a mouth of the tube and made of an insulating substance serving as a support for supporting and maintaining the first lead line and the second lead line to be spaced apart from each other;
an insulation pipe which is disposed in an inner space formed by the tube and the packing and encloses the first and second lead lines for securing insulation around the first and second lead lines placed inside the tube; and
an insulation ring for securing insulation between the heating coil inside the tube and a closed end portion of the tube,
wherein the insulation ring includes an opening passing through a body of the insulation ring.
11. The heater for the electronic thermostat according to claim 10 , wherein the opening of the insulation ring is filled with the insulation material.