KR20040076926A - Apparatus for heating cooling water in diesel engine using PTC thermistor heating elements - Google Patents

Abstract

PURPOSE: An apparatus for heating cooling water of a diesel engine using PTC elements is provided to prevent a cooling apparatus from being overheated by cutting off a current by rapidly increasing resistance if a temperature of a heating part becomes higher than a predetermined temperature. CONSTITUTION: An apparatus for heating cooling water is formed of a PTC(Positive Temperature Coefficient) heater(10) including a pair of heat sinks(12) and a plurality of PTC elements(11) connected with electrodes(13) respectively in a state that the plurality of PTC elements are inserted into mounting grooves(12a-2) of the heat sinks. The PTC heater has sealing grooves(12a-1,12b-1) formed at an inside combination surface(12a) and an outside cover combination body(12b), and an insert rubber(14) and a sealing rubber(15) installed at the sealing grooves respectively.

Description

Apparatus for heating cooling water in diesel engine using PTC thermistor heating elements}

The present invention relates to a cooling water heating device for a diesel engine using a PTC element, and more particularly, a positive temperature coefficient (PTC) in which a heating value is relatively increased or decreased depending on the ambient temperature in a cooling device for a diesel engine applied to an automobile. By using a heating element having a heating element to prevent the overheating of the cooling device by applying a heating method such that the current is cut off by a sudden increase in resistance even if the heating portion is exposed to the air due to the leakage of cooling water due to the leakage of cooling water. In addition, it is possible to use a heater that generates heat near the Curie temperature by using the characteristics of such a device, and more particularly relates to a cooling water heating device of a diesel engine using a PTC element that can maintain a constant temperature without a separate current regulator.

In general, the mixture of air and fuel combusted inside an engine cylinder of an automobile rises to a temperature of 2200 ° C. or higher, so the engine becomes very hot, but the cylinder wall should not be hot above about 260 ° C.

Higher temperatures will cause lubricants to decompose or degrade lubrication, and damage other engine components.

Thus, the coolant is circulated into the engine to prevent overheating of the engine to remove excess heat, which is about one third of the heat generated during combustion in the combustion chamber.

Some basic components are used to control the temperature of the coolant applied to the automobile engine. As shown in FIG. 6, the cooler is driven by the engine 100 to direct the coolant to the outside of the water jackets. And a thermostat 120 of a thermostatic valve type to control the flow of the coolant, and a portion of the heat generated by the engine through the coolant. It consists of a radiator 130 and the like emitted.

As such, the coolant that performs temperature control of the engine 100 while circulating in the engine 100 heats the vehicle interior with heat generated in the combustion chamber of the engine 100 while circulating the heater core 150 of the air conditioning apparatus in winter. It is supposed to be.

However, among the engines, diesel engines, unlike gasoline engines, have high thermal efficiency, and thus, it takes longer for the cooling water of the engine to heat up than the gasoline engine from the initial start of the vehicle.

Therefore, the vehicle equipped with the diesel engine in winter has a problem that the heating of the cooling water is delayed after the initial start-up, the indoor heating performance is lowered.

In order to solve these problems, an electric heater 140 is mounted to heat the cooling water by receiving electric power from a vehicle's power supply at an initial stage of startup.

As shown in FIG. 7, the electric heater 140 uses a plug-type heater in which a metal heating wire such as nichrome wire is embedded, and the plug heater uses about 2 to 4 coolants according to the amount of heat required. The heating is turned on and the engine is turned on so that the coolant reaches a temperature sufficient for heating and the power is turned off to terminate the function.

The plug-type heater is heat-exchanged while the heat generating portion is in contact with the cooling water, and during operation the heat generating portion temperature is maintained below 100 ℃ because the heat quantity of the heat generating portion continues to move toward the cooling water.

However, when the coolant of the engine flows out, the heat generating portion of the electric heater 140 is exposed to the air and continuous heat exchange is not performed, thereby increasing the temperature of the heat generating portion to 600 to 800 ° C.

If this condition persists, the heat of the heat generating portion is transferred to the peripheral body to which the electric heater 140 is fastened, and the temperature of the cooling water hose fastening portion where the cooling water enters and rises to 300 ° C. or higher, so that the hose is deformed, melted, or ignited. This increases the risk of fire in the vehicle.

In addition, since the heating coil material of the electric heater 140 is made of a metal such as nichrome wire, even if the heating part contacts the cooling water, the coil temperature reaches 600 ° C. or higher during the heating, so that the heating coil is surrounded by oxygen at such a temperature. There is a problem in that the endurance life of the coil is lowered because it forms an oxide by oxidation.

Accordingly, the present invention has been made to solve the above problems, the heat generating portion in the air due to the leakage of the cooling water by using a heating element having a positive temperature coefficient (PTC) resistance changes according to the ambient temperature Even if exposed, by applying a heating method that the resistance is rapidly increased to cut off the current when the temperature exceeds the predetermined temperature (Curi temperature), not only prevents overheating of the cooling device, but also forms a heating element made of a ceramic material to deteriorate oxidation due to heat generation. The purpose of the present invention is to provide a cooling water heating device for a diesel engine using a PTC element having excellent durability.

In addition, another object of the present invention is to produce a heater in the form of a plate in addition to the above to increase the contact surface area with the cooling water compared to the conventional plug form to improve the heat exchange efficiency, PTC can achieve the equivalent heating performance at low temperatures It is an object to provide a cooling water heating device of a diesel engine using the device.

1 is an exploded perspective view showing a cooling water heating device of a diesel engine using a PTC device according to the present invention;

2 is a perspective view showing a cooling water heating device of a diesel engine using a PTC device according to the present invention;

3 is an assembly view of a heater module using a basic PTC device according to the present invention;

4 is a graph showing a temperature resistance curve of a PTC device according to the present invention;

5 is a graph showing the vehicle heating test results of the present invention and the prior art,

6 is a conceptual diagram showing a cooling water line of a general diesel engine,

7 is a perspective view showing a conventional electric heater.

<Explanation of symbols for the main parts of the drawings>

10: PTC heater 11: PTC element

12: heater body 12a: coalescing surface

12a-1: Sealing groove 12a-2: Mounting groove

12b: cover assembly 12b-1: sealing groove

12c: uneven surface 13: electrode

14: insert rubber 15: sealing rubber

16: screw 20: case

30: cover

Hereinafter, the features of the present invention for achieving the above object are as follows.

The present invention is a cooling water heating apparatus mounted on the cooling water line of the diesel engine to heat the cooling water,

The cooling water heater is a plurality of heater body 12 is possible to coalesce and a plurality of electrodes 13 are connected to each other in the form of being inserted / mounted in the mounting groove 12a-2 in the heater body 12. Characterized in that the PTC heater 10 including the PTC element (11).

In particular, the PTC element 11 and the heater body 12 is characterized by consisting of a plate-like structure.

In addition, the PTC heater 10 forms sealing grooves 12a-1 and 12b-1 on the inner union surface 12a and the outer cover assembly 12b of the heater body 12 so as not to be exposed to cooling water. And a sealing structure in which the insert rubber 14 and the sealing rubber 15 are embedded in each of the sealing grooves 12a-1 and 12b-1.

The PTC element 11 is characterized in that the number can be adjusted according to the required amount of heat generated and heat generated area.

On the other hand, the surface of the heater body 12 is characterized in that the concave-convex surface 12c for securing the heat exchange area is formed.

The PTC heater 10 is characterized in that the coupling structure coupled to the tubular case 20 by the cover 30.

Hereinafter, the configuration of the present invention with reference to the accompanying drawings in detail.

1 is an exploded perspective view showing a cooling water heating device of a diesel engine using a PTC device according to the present invention, Figure 2 is a perspective view showing a cooling water heating device of a diesel engine using a PTC device according to the invention, Figure 3 The assembly diagram of the heater module using the basic PTC element according to the present invention is shown.

4 is a graph showing the temperature resistance curve of the PTC device according to the present invention, Figure 5 is a graph showing the vehicle heating test results of the present invention and the prior art.

As shown in FIG. 1, a heating device mounted on a cooling water line of a diesel engine to heat the cooling water includes a heating element having a positive temperature coefficient, that is, a PTC element 11. The element 11 is a sensor having a function of an economical and efficient heating element in which a heating value increases when the temperature decreases and the heating value decreases again when the temperature decreases. When the temperature is maintained above a predetermined temperature (Curie temperature), the resistance rapidly increases and the current is cut off.

The PTC element 11 having such characteristics is integrally modularized by a heater sink 12 so as not to be exposed to cooling water. As shown in FIG. 3, a pair of basic heater modules are provided. The PTC element 11 in which the electrode body 12 is connected between the heater body 12 made of a plate shape and inserted into the mounting groove 12a-2 of the heater body 12. Is sealed by sealing means and fastened by bolts or brazed (brazed).

As described above, in the preferred embodiment according to the present invention having an assembly form of the basic heater module, the PTC heater 10 performing a heat exchange action with the cooling water is mounted in the tubular case 20 made to flow the cooling water. In the following embodiment, the PTC heater 10 is inserted so that a total of six PTC elements 11 are three in a row.

1 is an exploded perspective view showing a cooling water heating device of a diesel engine using a PTC element according to the present invention, reference numeral 20 denotes a tubular case in which cooling water flows in association with a cooling water line of a general diesel engine.

The case 20 has a groove having a predetermined shape so that the cooling water heater, that is, the PTC heater 10 is mounted at the bottom thereof, and the heater body 12 of the PTC heater 10 is fitted to both sides thereof. A cover 30 having a predetermined shape is formed.

On the other hand, as described above, the PTC heater 10 is assembled in the same form as the assembly form of the basic heater module of Fig. 3, the heater body 12 of aluminum material made of a pair of plate-like form, and the heater It is composed of a PTC element 11 which is connected to the mounting groove 12a-2 of the body 12 to be completely inserted between the electrodes 13, respectively.

The PTC elements 11 are arranged so that a total of six pieces of three elements in a row overlap each other, and each electrode 13 inserted therebetween is connected to a power source (not shown) to which electric power of a vehicle is supplied.

The PTC heater 10 having such an assembly structure includes an insert rubber 14 inserted into a sealing groove 12a-1 formed in the inner union surface 12a of the heater body 12, and the heater body ( 12 is sealed by a sealing rubber (15) inserted into the sealing groove (12b-1) formed in the cover assembly (12b) integrally formed, and fastened by a screw (16) so as not to be exposed to the cooling water. On the other hand, the surface of the heater body 12 is formed with an uneven surface 12c for securing the heat exchange area.

As shown in FIG. 2, the PTC heater 10 assembled as described above is mounted to the case 20 by the cover 30, and the PTC heater 10 is formed in a plate shape to form a coolant. The contact surface area is increased compared to the conventional plug type to improve heat exchange efficiency, so that even at low temperatures, equivalent heating performance can be achieved.

In addition, as in the above embodiment, the PTC heater 10 in which the heater body 12 and the PTC element 11 are integrally modularized may control the number of PTC elements 11 according to the required heat generation amount and heat generation area.

3 is a graph showing the temperature resistance curve of the PTC device according to the present invention, wherein the PTC device used herein has a Curie temperature of 200 ° C. or higher and an operating resistance of 3 Ω or lower.

As shown in the graph, the resistance is constant until the Curie temperature (200 ° C.), but when the temperature is 200 ° C. or more, the resistance value is rapidly increased.

As described above, when the cooling water generates heat by the PTC element 11 which is a heat generating element and rises above a predetermined limit temperature, the resistance value is rapidly increased due to the characteristics of the PTC element.

Therefore, the PTC element 11 can be used as a heating device that generates heat near the Curie temperature, and in particular, the PTC device 11 can be maintained at a constant temperature without a separate current controller.

On the other hand, Figure 5 is a graph showing the vehicle heating test results of the present invention and the prior art at -20 ℃, in order to measure the performance of the PTC heater 10 with the existing electric heater (metal) 140 heating of the vehicle As a result of measuring the performance, as shown in the accompanying drawings, the PTC heater 10 of the present invention exhibits an equivalent level of performance in comparison with a conventional metal heating material product.

Moreover, unlike the existing metal heating material products, the heating element itself, that is, the PTC element 11 is made of a ceramic material mainly made of barium titanate (BaTiO ₃ ), there is no oxidation deterioration due to heat generation in the air, durability This is a very good performance improvement.

Therefore, the cooling water heating device of the diesel engine using such PTC element is an invention capable of stably and efficiently heating the interior of an automobile.

As described above, the cooling water heating device of the diesel engine using the PTC element according to the present invention is heated so that the resistance is rapidly increased when the heating element is exposed to the air due to the coolant outflow, the resistance is rapidly increased to cut off the current. By applying the method, it is possible not only to prevent overheating of the cooling device, but also to use a heater that generates heat near the Curie temperature by using the characteristics of such a device, and in particular, to maintain a constant temperature without a separate current regulator, Is made of ceramic material, so there is no oxidative deterioration due to heat generation, and it is excellent in durability.The heater is made in the form of plate, and the contact surface area with the coolant is increased compared to the conventional plug type, so that the heat exchange efficiency is improved, so that even heating at low temperature This has the effect of achieving performance.

Claims (6)

In the cooling water heating device mounted on the cooling water line of the diesel engine to heat the cooling water, The cooling water heater is a plurality of heater body 12 is possible to coalesce and a plurality of electrodes 13 are connected to each other in the form of being inserted / mounted in the mounting groove 12a-2 in the heater body 12. Cooling water heating device for a diesel engine using a PTC element, characterized in that the PTC heater (10) comprising a PTC element (11). The apparatus of claim 1, wherein the PTC element (11) and the heater body (12) have a plate-like structure. The method of claim 1, wherein the PTC heater 10 is sealing grooves (12a-1, 12b-1) in the inner union surface 12a and the outer cover assembly (12b) of the heater body 12 so as not to be exposed to the cooling water ) And a sealing structure in which the insert rubber (14) and the sealing rubber (15) are built into each of the sealing grooves (12a-1, 12b-1). Heating device. The apparatus of claim 1 or 2, wherein the PTC element (11) can adjust the number of the PTC element (11) according to the required heat generation amount and heat generation area. The apparatus of claim 1 or 2, wherein the surface of the heater body (12) is formed with an uneven surface (12c) for securing a heat exchange area. The apparatus of claim 1 or 3, wherein the PTC heater (10) has a coupling structure coupled to the tubular case (20) by a cover (30).