JPS601507Y2 - heating device - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a heating device.

As a relatively small-capacity heating device, heating devices that use electricity as an energy source are widely used because of their ease of handling.A typical heating device of this type is a resistance wire heater such as a nichrome wire heater. There is something I used.

However, in conventional heating devices using resistance wires, it is necessary to install a temperature-sensitive switch to control the heating temperature, which makes the device complicated and takes time to assemble. It is extremely difficult to maintain the heating temperature at a predetermined value with high precision even if the heating temperature is provided.

Therefore, the present applicant previously proposed a heating device using a thermistor element having a positive temperature coefficient as a heating element (Utility Application No. 106629/1982).

This proposed heating device has a heat dissipation fin with a hollow part, and houses a heat generating assembly in which an insulating plate, an electrode plate, and a thermistor element having a positive temperature coefficient are configured in a laminated structure. The lead is attached to a shaped electrode plate such that the thermistor element contacts one inner wall of the hollow part and the electrode plate is electrically insulated from the other inner wall of the hollow part by an insulating plate. It is constructed so that heating power is supplied between the wire and the radiation fin made of a material with good electrical conductivity.

However, in this proposed heating device, only one side wall of the radiation fin is directly heated by the thermistor element, so the amount of heat generated is extremely small, and the radiant heat from the radiation fin is not uniform, so the temperature This had drawbacks such as non-uniform distribution.

Therefore, the present invention aims to improve the above-mentioned drawbacks of the prior art, and its purpose is to provide a heating device that is small in size, generates a large amount of heat, and uniformly radiates heat from its radiation fins.

The heating device according to the present invention, which is related to this purpose, is characterized by an arrangement of a plurality of heat dissipation fins each having a hollow part made of a metal with good thermal conductivity, and a plurality of heat dissipation fins arranged in the hollow part in contact with the inner wall of the heat dissipation fins. a first thermistor element having a positive temperature coefficient, an electrode plate in contact with the first thermistor element, and a second thermistor element having a positive temperature coefficient in contact with both the electrode plate and the inner wall of the radiation fin. The heating device has a laminated structure, an outer casing that supports the arrangement of the radiation fins, and a lead wire that passes through the outer casing and is connected to the electrode plate.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 shows an embodiment of a carburetor for a gasoline internal combustion engine equipped with the heating device of the present invention.

As shown in FIG. 1, this carburetor 10 takes in an air flow A supplied through an air cleaner (not shown) by regulating the flow rate with a choke valve 2 provided in an intake manifold 1, and takes in the air flow A through a nozzle 3. Gasoline supplied to the nozzle 3 is atomized by a vaporization mechanism consisting of a fuel cell and a pentieri 4, and the atomized gasoline 5 is mixed with the air flow A at the theoretical air fuel efficiency, the flow rate is adjusted by a slot valve 6, and the gas is 7 to an engine room (not shown).

By the way, in order to ensure optimal combustion operation in the engine room, it is necessary to supply gasoline and air with minute particle sizes as a mixed gas based on the stoichiometric air-fuel ratio. In a gasoline internal combustion engine, since the intake manifold 1 and the passage 7 are cold, the gas mixture of gasoline and air is reliquefied while being sent to the engine compartment, and therefore may flow into the engine compartment as a fluid. These problems include worsening fuel efficiency and emitting harmful exhaust gas.

This tendency is particularly noticeable when starting the engine in winter.

In order to solve this problem, this vaporizer 10
In order to heat the liquefied gasoline and vaporize it again in the event that the gasoline once vaporized inside the vaporizer liquefies for some reason, the bottom wall 8a of the recess 8 located at the bottom of the vaporizer 10 is heated. Device 11 is glued.

FIG. 2A is an enlarged sectional view of the heating device 11 shown in FIG. 1, and FIG. 2B is a perspective view of the heating device 11.

The heating device 11 has an array of a plurality of radiation fins 20 (three in the embodiment) made of a metal with good thermal conductivity (for example, copper), and the fins are molded integrally with the support base 20a.

Inside the fin 20, the inner walls are parallel to each other and are opposed to each other, with an intermediate portion between the inner walls.

A laminated structure including a thermistor element 21, an electrode plate 22, and a thermistor element 23 is inserted into the hollow portion as shown.

Both thermistor elements 21 and 23 have a thin plate structure and have a positive temperature coefficient (p'rc; Po5itive Tempe
rate Coefficient).

Each side of the thermistor element 21 , 23 is in contact with the electrode plate 22 , and each other side is in contact with the inner wall of the radiation fin 20 .

Therefore, by applying a voltage between the electrode plate 22 and the radiation fin 20, current flows through both thermistor elements 21 and 23, and these elements generate Joule heat and generate heat.

The support base 20a of the heat dissipation fin is mounted on a heat insulating outer casing 25 as shown in the figure.
It is fixed by a bolt 26.

The heat-insulating outer casing 25 is made of a material with excellent heat-insulating properties, such as glass-filled Teflon.

Note that a ring-shaped gasket 28 with good cushioning properties is inserted into the lower end of the support base 20a.

By tightening the bolts 26, this gasket 28 ensures airtightness between the support base 20a and the heat insulating outer casing 25, and prevents gasoline vapor from entering through the gap H and touching the thermistor element.

Note that a lead wire 2 common to all electrode plates is connected from the electrode plate 22.
4 is provided by penetrating the center of the bottom of the heat insulating outer casing 25.

Also, a plurality of bolt holes 27 are formed around the periphery of the heat insulating outer casing 25, and the heating device 11 is fixed to the bottom 8a of the intake manifold by bolts inserted into the holes.

As mentioned above, when a voltage is applied between the lead wire 24 and the bolt 26 with the heating device 11 fixed to the bottom 8a of the intake manifold, the thermistor elements 21 and 23 are energized and generate heat.

Since the thermistor element is provided in close contact with the two inner wall surfaces of the heat dissipation fin hollow part, the amount of heat radiated from the heat dissipation fin 20 is large and uniform, and a large amount of heat is obtained despite the small size. be able to.

The heat generated by the thermistor elements 21 and 23 is transmitted to the intake manifold via the radiation fins 20, and the gasoline is vaporized.

Since the thermistor element immediately generates heat when energized, it has extremely good vaporization characteristics when starting the engine.

Furthermore, since the thermistor element has a positive temperature coefficient, as the temperature rises, the electric resistance of the element itself increases and the current decreases.

In this way, since the thermistor elements 21 and 23 have positive temperature coefficients, the heating element itself controls the temperature of the heat generated, and therefore the temperature of the thermistor element rises above a certain value. This property is effective in preventing accidents.

As is clear from FIGS. 2A and B, it is the heat-insulating outer casing 25 that is in direct contact with the inner wall (usually made of aluminum) of the intake manifold, and the radiation fins 20 are thermally insulated from the inner wall of the intake manifold. has been done.

Therefore, the heat from the radiation fins does not escape through the walls of the intake manifold, and all of the generated heat contributes to the vaporization of gasoline.

Furthermore, one of the features of the present invention is that the thermistor element does not come into direct contact with the object to be heated (gasoline in this embodiment). Air is replenished, so
Stable operation of the thermistor element over a long period of time is guaranteed.

Furthermore, as already mentioned, when the engine is warm, the resistance value of the thermistor element increases, so power consumption is small, making it ideal as a battery-powered carburetor.

Therefore, it is sufficient to link the power switch to the thermistor element with the engine key.

Although the above embodiment shows a case where the heating device according to the present invention is installed in a vaporizer, the heating device according to the present invention is not limited to being attached to a vaporizer.

According to the present invention, since the heat generated by the thermistor element having a positive temperature coefficient is utilized, the element itself has the characteristic of maintaining the heat generation temperature at a predetermined value, and the thermistor element as the heat generating element is installed in the hollow part of the heat dissipation fin. It has a laminated structure consisting of an element and an electrode plate, and the thermistor element directly heats the inner wall surface of the hollow part of the heat dissipation fin, so it is small and can generate a large amount of heat, and is highly efficient, as well as distributing heat uniformly from the heat dissipation fin. Furthermore, since the heat dissipation fins are used as electrodes, the structure is simplified and the time required for assembly is significantly shortened compared to conventional heating devices.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an embodiment of a vaporizer equipped with a heating device according to the present invention, and FIGS. 2A and 2B are an enlarged sectional view and a perspective view of the heating device shown in FIG. . 11; heating device, 20; radiation fins, 21, 23: thermistor element, 22; electrode plate, 24; lid wire, 25; heat insulating outer casing.

Claims (1)

[Scope of utility model registration request] an array of a plurality of heat dissipation fins each having a hollow part made of metal with good thermal conductivity, a first thermistor element having a positive temperature coefficient provided in the hollow part in contact with an inner wall of the heat dissipation fin, and the first thermistor element having a positive temperature coefficient; a laminated structure including an electrode plate in contact with the thermistor element and a second thermistor element having a positive temperature coefficient in contact with both the electrode plate and the inner wall of the heat dissipation fin; an outer casing that supports the arrangement of the heat dissipation fins; A heating device comprising: a lead wire that passes through an outer casing and is connected to the electrode plate.