JPS6335184Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates primarily to improvements in air heater devices used in diesel engines.

(Prior Art and its Problems) In order to raise the temperature of the intake air and improve the ignitability when starting the engine, a heating device is installed in the middle of the intake passage.

One example of this intake device is an electric air heater as shown in FIG. 1, for example.

This means that the intake system corresponds to the two cylinder groups.
This air heater device is installed at the inlet of a divided intake manifold (see Figure 2), and its plate-shaped heater frame 1 has two openings formed by a central partition wall 2 corresponding to the divided passages. Part 3
a and 3b are formed.

In the two openings 3a and 3b, as shown in the figure, a series of ribbon-shaped heating elements (heating wires) 4 which are sequentially folded back and formed into a wave shape are placed in a positional relationship in which the straight portions 4s thereof are approximately parallel to the partition wall 2. One end 4a of the heating element 4 is connected to a terminal 5a electrically insulated and supported by the heater frame 1.
Similarly, the other ends 4b are respectively connected to terminals 5b which are grounded to the heater frame 1.
Note that the heating element 4 is also supported in an electrically insulating manner at a portion that crosses the partition wall portion 2.

Further, the heating element 4 includes a plurality of insulators 6 disposed facing each other so as to sandwich the folded portions 4f at both ends thereof.
The insulator 6 is held on the heater frame 1 via a holder 7 having a substantially U-shaped cross section.

In such a ribbon-shaped heating element 4, there is a risk that the linear portion 4s will be deformed in a buckling manner due to thermal expansion when electricity is generated, and adjacent elements may come into contact with each other and cause a short circuit. In this device, a plurality of insulators 6 are provided, and two adjacent insulators 6
A part of the heating element folded part 4f is held between the parts, and this part is designed to absorb the thermal expansion. (Refer to Japanese Utility Model Publication No. 56-1955.) By the way, if the span of the ribbon-shaped heating element 4, that is, the length of the straight portion 4s, is increased beyond a certain level, the amount of deformation due to the thermal expansion described above will also increase accordingly. It becomes structurally difficult to do so, and also causes problems in terms of strength, such as vibration caused by the action of intake pulsation and easy damage.

For this reason, in the conventional air heater device described above, there are limits to the shape and dimensions of the openings 3a and 3b.
For example, if an attempt is made to enlarge the opening area in response to an increase in the engine displacement, that is, the intake flow rate, the openings 3a and 3b will have to be enlarged in the left-right direction in FIG. 1, and as a result, there is a risk of deviation from the appropriate passage shape. There was.

On the other hand, for example, Japanese Utility Model Application Publication No. 57-13864 discloses a system in which multiple rows of heating elements are provided. The problem of shape and size limitations is resolved.

However, in this air heater device, a beam-shaped support means is provided to support the holders of the heating elements adjacent to each other with respect to the metal square frame so as to cross the intake passage. Since the structure is such that the air heater is assembled in advance, there are problems in that it takes many man-hours to attach the air heater to the intake pipe, and the number of parts increases as the support means is required.

Furthermore, in this type of air heater device, as described above, a beam-shaped support means is provided across the intake passage portion in order to support adjacent portions of multiple heating elements, which tends to increase intake resistance.

The present invention aims to solve these conventional problems.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a heating element that is sequentially folded back to form a wave shape, and a holder that holds the folded parts on both sides facing each other through an insulator. In an air heater device housed in a heater frame held in the middle of an engine intake pipe, the heating elements are arranged in a plurality of rows so that holders for holding them are positioned in parallel, and the heating element rows are arranged in parallel. A support portion having a spindle-shaped cross section is provided to sandwich the adjacent holders from the upstream side and the downstream side at the adjacent portion so as to cross the intake passage, and at least one of the upstream side support portion or the downstream side support portion is connected to the It is integrally formed into the tube.

(Function) In the above configuration, one of the pair of support parts that holds the adjacent parts of the plurality of holders from above and below is provided integrally with the intake pipe, so that it is easy to assemble the air heater to the intake pipe. The work becomes easier and the number of parts is reduced. Further, since the support portion has a spindle-shaped cross section, the intake resistance around the holder is reduced.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. Note that substantially the same parts as in FIG. 1 are designated by the same reference numerals.

In the present invention, for example, as shown in FIG.
7o are arranged in parallel or parallel to each other.

That is, the heater frame 11 has the partition wall portion 1.
2 to form two openings 13a and 13b, and holders 7i and 7o holding the heating element 4 through the insulator 6 are housed in each in parallel to each other. Note that the partition wall portion 12 does not necessarily need to be provided.

One end portion 4c of each of the two rows of heating elements 4 is connected to two terminals 5c insulated and supported on the heater frame 11, and these two terminals 5c.
electrically connected via a conductive piece 15 connecting
The other end 4a of the heating element 4 on the right in the figure is connected to a lead wire from a power source (not shown) via a terminal 5a which is also insulated and supported, while the other end 4b of the heating element 4 on the left is connected to a terminal 5b. The heater frame 11 is grounded through the heater frame 11.

In the present invention, as shown in FIG. Upper and lower support parts 18 and 19 are provided to sandwich and support the partition wall part 12 and the mutually adjacent inner holders 7i.

The upper and lower support parts 18 and 19 are provided on the intake pipes 16 and 17, respectively, and at least one is formed integrally with the intake pipe 16 or 17, and one of them is formed integrally with the partition wall part 12. You may also do so. Further, as shown in the figure, the upper and lower support portions 18 and 19 are each formed to have a spindle-shaped cross section. Furthermore, in this case, the support parts 18, 19
When the width is L and the height is H, [(L/3)<
It is appropriate to determine the dimensions and shape so as to satisfy the relationship: H<3L].

Note that the holder 7o on the outside of both heating element rows A and B
are held between the flanges 16a and 17a of the intake pipes 16 and 17, respectively, as in the conventional case.

In a state where the heating element rows A and B are only arranged on the heater frame 11, the holders 7i and 7o are located at the opening 1.
It only fits along one side of 3a or 13b, but connect it to the intake pipe 1 as shown in Figure 4.
By sandwiching them between 6 and 17 and tightening them together using bolts (not shown), the inner holder 7i can be secured by the upper and lower support parts 18 and 19 as described above.
Furthermore, the outer holder 7o is the intake pipe flange portion 16.
a and 17a, each is firmly fixed. Therefore, no special consideration is required when attaching the heater frame 11.

By the way, in the present invention, as shown in the above embodiment, since the plurality of heating element rows A and B are arranged in parallel with each other, the effective intake passage cross-sectional area can be increased without increasing the span of the heating elements 4 compared to the conventional one. It can be expanded, and even in that case, problems such as the cross-sectional shape of the passage becoming unnecessarily elongated will not occur. In other words,
In order to expand the cross-sectional area of the passage in Figure 3, it is sufficient to increase the vertical dimensions of the figure as a whole.
If this is still insufficient, or if the cross-sectional shape of the passage becomes inappropriate, this can be dealt with by providing three or more rows of heating elements.

(Effects of the invention) As described above, according to the invention, a large intake passage cross-sectional area can be secured without increasing the span of the ribbon-shaped heating element, and therefore it is applicable to large internal combustion engines and has high reliability. Not only does it have the advantage of being high as a dual air heater device, but it also has a support section with a spindle-shaped cross section that holds the adjacent parts of multiple holders from above and below, reducing intake resistance around the air heater holders and improving engine intake. In addition to improving efficiency, since at least one of the upstream and downstream support parts is integrally formed with the intake pipe, the holder can be easily held when assembling the air heater to the intake pipe. The practical effects of reducing the number of assembly steps and reducing the number of parts compared to the case where the holder support means is provided separately from the intake pipe can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a front view of an example of a conventional air heater device, and FIG. 2 is a plan view of an intake manifold for explaining the installation state thereof. FIG. 3 is a front view of one embodiment of the present invention, and FIG. 4 is a plan cross-sectional view of the same when it is attached to an intake pipe. 4... Heating element, 6... Insulator, 7i, 7o... Holder,
11... Heater frame, 12... Partition wall part, 13
a, 13b...opening, 16...intake pipe, 17...intake pipe (intake manifold), 18, 19...support part.

Claims (1)

[Scope of utility model registration request] An air heater device in which a heating element formed into a wave shape by sequentially folding back and a holder that holds the folded parts on both sides facing each other through an insulator are housed in a heater frame which is held in the middle of an engine intake pipe.
The heating elements are arranged in a plurality of rows so that holders holding the heating elements are located in parallel, and the mutually adjacent holders of each heating element row are held between the upstream side and the downstream side at the adjacent portions. A support section with a spindle-shaped cross section is provided across the intake passage,
A dual air heater device for an internal combustion engine, characterized in that at least one of the upstream side support portion and the downstream side support portion is integrally formed with an intake pipe.