JPH0521613Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention is designed to reburn unburned particles such as carbon contained in the exhaust of automobiles equipped with internal combustion engines, especially diesel engines, in the exhaust tract. The present invention relates to an exhaust gas heater.

[Prior Art] For example, as shown in FIG. 7, in the conventional exhaust gas heater 20, when the sheathed heater 22 as a heat generating element is attached to the heater case 21, a mounting plate is provided on the outside of the tube 22a of the sheathed heater 22. The metal fitting 23 is fixed by brazing or the like, and this metal fitting 2
The sheathed heater 22 is attached by fixing it with a nut 24.

[Problems to be solved by the invention] However, when attaching the sheathed heater 22 to the heater case 21 in this way, the metal fittings 23 and the nuts 24 are required, which increases the number of parts and the manufacturing process. case 21
Since a fitting hole must be provided that is larger than the outer diameter of the metal fitting 23, the heater case 21 needs to have a sufficient thickness relative to the outer diameter of the metal fitting 23, resulting in an increase in weight.

The present invention aims to reduce the number of parts in an exhaust gas heater, simplify the manufacturing process, and reduce its weight.

[Means for Solving the Problems] The present invention provides a filter installed in an exhaust path for guiding exhaust gas emitted from an internal combustion engine, etc. to the outside, upstream of a filter for capturing unburned particles in the exhaust gas. In the exhaust heater, the exhaust heater includes a plurality of electric heating elements provided at both ends, and an annular frame forming a part of the exhaust passage and fixing the plurality of electric heating elements. It consists of a plurality of sheathed heaters having a substantially horseshoe shape and having a current-carrying electrode thereon, and the annular frame has a plurality of holes that penetrate the plurality of sheathed heaters from the inside to the outside,
The technical means of the plurality of sheathed heaters is that each energizing electrode is disposed on the outer circumferential side of the annular frame, penetrates the annular frame, and is directly joined to the annular frame.

[Operation and Effects of the Invention] In the present invention, the annular frame has a plurality of holes through which the plurality of sheathed heaters penetrate from the inside to the outside, and the sheathed heater, which has a substantially horseshoe shape, penetrates the annular frame and has a plurality of holes through which the sheathed heaters penetrate from the inside to the outside. Connected directly to the frame. Therefore, brazing or welding can be used to join the sheathed heater and the annular frame, and there is no need to equip the sheathed heater with metal fittings for fixing it to the annular frame. The number of points is reduced, and the process associated with fixing the metal fittings can be eliminated.

In addition, since no mounting hardware is used,
Since the annular frame only needs to be provided with a small through hole that corresponds to the diameter of the sheathed heater, the width of the annular frame can be reduced and the weight of the exhaust heater can be reduced. It is possible to save labor when moving and transporting the heater as a component.

[Example] Next, embodiments of the present invention will be described based on the drawings.

The exhaust gas heater 1 of this embodiment shown in FIG.
It is composed of a heater case 2 as an annular frame and sheathed heaters 3 and 4.

The heater case 2 is made of, for example, cast iron, stainless steel,
It is an annular frame made of a heat-resistant material such as titanium alloy, and as shown in the figure, the heater case 2
In order to install each sheathed heater 3 and 4,
Four holes 2a are provided in a row so that the inside and outside of the heater case 2 communicate with each other.

The sheathed heaters 3 and 4 are well-known electric heating elements in which heating wires (not shown) are provided in heat-resistant metal tubes 3A and 4A filled with insulating powder such as magnesium oxide, respectively. It has a shape.

Here, the sheathed heater 4 has an approximately horseshoe shape that is curved one size smaller than the sheathed heater 3 in order to heat the inner part of the sheathed heater 3, and the sheathed heater 4 has a substantially horseshoe shape that is curved one size smaller than the sheathed heater 3. I'm doing well.

Each end of the sheathed heaters 3 and 4 is provided with current-carrying electrodes 3a, 3b, 4a, and 4b connected to the heating wires within each sheathed heater 3 and 4, and these electrodes are connected to an insulating member 5. tube 3A,
4A and insulated.

The sheathed heaters 3 and 4 are fitted into each hole 2a from the inside of the heater case 2, and each tube 3A,
It is fixed by a foil-like solder provided on the surface of 4A. Note that an appropriate clearance is provided between the hole 2a and each tube 3A, 4A, and since each sheathed heater 3, 4 is elastically deformed by an external load, it is easily connected to the hole 2a. can be inserted into.

In this way, in the present invention, each sheathed heater 3, 4
Since it is directly connected to the heater case 2, compared to the case where it is connected through mounting metal fittings, it is necessary to set the diameter of the hole 2a in the heater case 2 to match each tube 3A, 4A. Therefore, the thickness of the heater case 2 can be reduced. Therefore, the exhaust gas heater 1 can be manufactured as a lightweight component.

Further, since there are no parts interposed between the heater case 2 and each sheathed heater 3, 4, the manufacturing process can be simplified.

Furthermore, each of the sheathed heaters 3 and 4 has a substantially horseshoe shape as described above, and since the degree of curvature thereof is different, each electrode can be provided in a concentrated manner in the heater case 2. Since the electrodes 3a and 4a and the electrodes 3b and 4b of the sheathed heaters 3 and 4, which are close to each other, can be connected to each other by connection plates (not shown), etc., it is possible to connect the sheathed heaters 3 and 4 with electricity. The lead wires only need to be connected to the electrodes 3a and 3b or the electrodes 4a and 4b, which greatly simplifies the wiring process.

The exhaust heater 1 having the above configuration has a second
It is provided close to the filter 12 shown in the figure.

This filter 12 is made of ceramic and has partition walls 12a arranged in a rectangular lattice shape in order to adsorb unburned particles such as carbon contained in the exhaust gas. The fuel is coated with platinum as a catalyst in order to re-burn it using the heat of the exhaust gas. As shown in FIG. 3, the filter 12 is connected to an exhaust pipe 1 that guides exhaust gas discharged from the engine of the vehicle 13 to the outside.
As shown in FIG. 4, the exhaust heater 1 has flanges 14c for connecting exhaust pipes 14a and 14b,
A plurality of fixing holes 2b are provided in the heater 2 and inserted between the holes 14d through gaskets (not shown).
It is fixed by bolts 15a and nuts 15b.

At this time, the lead wires for energizing each of the sheathed heaters 3 and 4 are only pulled out in one direction, for example, toward the side of the vehicle, under the chassis 16 of the vehicle 13; There is no need to provide a space for wiring in other directions such as above, above, and below. As a result, the exhaust pipe 14 and the chassis 16 can be brought into close contact with each other, and the mounting structure of the exhaust pipe 14 can be further simplified.

In this way, the exhaust heater 1
Since it is a part that is fixed to a vehicle assembly plant, it is transported to a vehicle assembly plant after manufacturing, but since the weight of the product is reduced according to this invention, it can be shipped within the parts assembly plant or transported to a vehicle assembly plant. In this way, it is possible to save labor. Furthermore, labor savings can be similarly achieved when managing parts within a vehicle assembly factory.

A second embodiment and a third embodiment of the present invention are shown in FIGS. 5 and 6, respectively. In order to simplify the explanation, the same functional objects are given the same numbers.

In the second embodiment, the annular heater case 2 is divided into two parts in the axial direction.
A, 2B are provided, grooves 2c, 2d are provided in both or one of them for fitting the sheathed heaters 3, 4, respectively, and after the sheathed heaters 3, 4 are arranged, the heater cases 2A and 2B are They are joined using wax foil.

In the third embodiment, a groove 2c deeper than the diameter of each sheathed heater 3, 4 is provided in the heater case 2, and after each sheathed heater 3, 4 is arranged, a fixing member 2e is brazed. This embodiment also eliminates the need for the metal fittings 23 and nuts 24 that were conventionally required, which reduces the number of parts and simplifies the manufacturing process.

As described above, according to the exhaust heater of the present invention, the number of parts can be reduced, the manufacturing process is simplified, and the weight of the exhaust heater is reduced, so movement and transportation can be omitted. be able to.

[Brief explanation of drawings]

FIG. 1 is a front view showing the first embodiment of the present invention, FIG. 2 is an exploded perspective view showing the exhaust gas heater and filter of the present invention, and FIG. 3 is a diagram of a vehicle equipped with the exhaust gas heater of the present invention. FIG. 4 is a side sectional view of the exhaust pipe showing the installed state of the exhaust gas heater of the present invention, FIG. 5 is an exploded perspective view showing the second embodiment of the present invention, and FIG. 6 is the exhaust pipe of the present invention. FIG. 7 is an exploded perspective view showing the third embodiment, and FIG. 7 is a front view showing the conventional example. In the figure, 1... Exhaust heating heater, 2... Heater case (annular frame), 3, 4... Sheathed heater.

Claims (1)

[Scope of Claim for Utility Model Registration] A plurality of filters provided upstream and close to a filter provided in an exhaust path that guides exhaust gas emitted from an internal combustion engine, etc. to the outside to capture unburned particles in the exhaust gas. An exhaust heater comprising an electric heating element and an annular frame forming a part of the exhaust passage and fixing the plurality of electric heating elements, wherein the plurality of electric heating elements have energizing electrodes at both ends. The annular frame has a plurality of holes that penetrate the plurality of sheathed heaters from the inside to the outside, and the plurality of sheathed heaters have each energizing electrode connected to the An exhaust gas heater for an internal combustion engine or the like, characterized in that it is disposed on the outer peripheral side of an annular frame, passes through the annular frame, and is directly joined to the annular frame.