JPH0452955Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an air heater used for preheating intake air of an internal combustion engine.

(Prior Art) It is sometimes difficult to start gasoline engines and diesel engines in cold regions during the winter due to the low outside air temperature. Therefore, air heaters are used to improve starting performance by preheating the air supplied to the cylinders of the engine. Third
The figure shows an external view of the air heater, where 1 is a heater element, 2 is an insulator, and 3 is a container frame. FIG. 4 shows the heater element 1 and insulator 2 in FIG. , each bent portion of the heater element 1 is inserted into a hole 4 provided corresponding to the bent portion of the heater element 1. Note that this insulator 2 is used on both the upper and lower sides of the heater element 1, and the heater element 1 is held by pressing the insulator from above and below with a leaf spring or the like. Further, FIG. 5 shows an example in which the insulator is divided into front and back parts at the top and bottom of the heater element 1, and each insulator is made up of a front insulator 2a and a rear insulator 2b each having a groove. It has a structure in which the bent portion of the heater element 1 is held between the front and back.

(Problem to be solved by the invention) Since the heater element expands due to heat generated by electricity, in order to prevent deformation due to this expansion, it is necessary to fit the bent part of the heater element into the hole or groove of the insulator. The structure was always such that there was a slight gap. Therefore, play may occur between the heater element and the insulator, and in the example shown in Fig. 5, the bent portion of the heater element may wear out due to vibration, which greatly reduces the durability of the heater element and reduces its reliability. It will lack sex.

(Means and effects for solving the problem) The present invention has been made to solve the above problems, and each adjacent bent portion on the same side of the heater element is arranged in a manner corresponding to the bent portion. To provide an air heater equipped with a heater part that is inserted into a hole formed in an insulator and is locked by alternately elastically biasing the front and rear walls in the width direction of the heater element inside the hole. It is.

As a means for alternately elastically biasing and locking the front and rear wall surfaces inside the hole, a step is provided at every other bent portion on the same side of the heater element formed by bending in a zigzag shape. In particular, the torsional spring properties of the heater element may be used to alternately elastically press the front and rear walls inside the hole of the insulator, or alternatively, the heater element may be the same as before without providing a step as described above. Instead, by forming every other hole in the insulator with a step between the front and back, it is possible to alternately press the front and rear walls inside the hole elastically in the same way as above. Become.

As described above, since the bent portion of the heater element is locked in the hole of the insulator by utilizing its spring property, even if a fitting gap is provided, no rattling occurs and the heater element is resistant to vibration.

(Embodiment) Fig. 1 shows an embodiment of the heater section of an air heater according to the present invention, and Fig. 1 shows a perspective view of the heater element. In A, the heater element 1A is a ribbon-shaped resistor bent in a zigzag shape as in the conventional example, but every other adjacent bent part on the same side is alternately provided with steps of d in the width direction. It is formed. B shows a front view seen from the direction of arrow M in A. C is a sectional view showing a state in which the heater element as described above is held by an insulator, in which each bent portion of the heater element 1A corresponds to a hole 2A formed in the insulator 2A.
1 are inserted respectively. Hole 2A-1 is provided without any step, so heater element 1A
The step d of the bent portion of the heater element 1A is optimally set so that the inner wall of the hole is elastically biased with appropriate pressure alternately in the directions of arrows N and N' due to the torsional springiness of the heater element 1A. ing.

FIG. 2 shows another embodiment of the heater section, and is a sectional view showing a state in which the heater element is held by an insulator. Unlike the above embodiment, the heater element 1B does not have a step at the bending part, and is different from the conventional example. It is similar, but instead, every other hole 2B-1 is formed in the insulator 2B with a step d in the front and back, and as a result, the same effect as in the above embodiment is obtained. In exactly the same way, the bent part of the heater element is indicated by arrow N.
This is a structure in which the inner wall of the hole is elastically biased in the directions of and N'.

As described above, since the bent portion of the heater element elastically presses against the inner wall of the hole in the insulator in the directions of arrows N and N', there is no play in the fitted portion. At the same time, it is possible to provide an appropriate fitting gap, thereby preventing deformation of the heater element due to thermal expansion. Note that this effect is limited to a temperature range in which the heater element material has springiness, and when the heater temperature rises above the transformation point, the pressure between the insulator and the bent portion becomes zero. However, since the dimensions are in sufficient contact, there is no play compared to conventional products.

(Effect of the invention) In the air heater of the invention, the bending part of the heater element in the heater part and the hole in the insulator that holds it are elastically held, so there is no play caused by engine vibration. In addition, sufficient fitting clearance can be provided between the insulator in the N and N' directions, so the heater element will not be deformed due to thermal expansion, resulting in a functionally stable and vibration-resistant structure. Air heaters can be provided.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the air heater according to the present invention.
A is a perspective view of the heater element, B is a front view seen from the direction of arrow M in A, C is a sectional view showing the state in which the heater element is held by an insulator, and
The figure is a sectional view showing the heater element held by an insulator in another embodiment of the air heater according to the present invention, Figure 3 is an external view of the air heater, and Figure 4 is a heater element and insulation in the heater section of a conventional air heater. FIG. 5 is a perspective view showing the relationship with the body. FIG. 5 is a cross-sectional view of another conventional heater element held by an insulator when viewed from above. 1A, 1B...Heater element, 2A, 2B
... Insulator, 2A-1, 2B-1 ... Hole, 3 ...
Vessel frame.

Claims (1)

[Scope of utility model registration request] In an air heater for an internal combustion engine, in which a heater section is housed in a container frame, each bent portion of a heater element made by bending a ribbon-shaped resistor in a zigzag shape and held by an insulator on both sides, the heater element is placed adjacent to the heater element on the same side. Each bent portion is inserted into a hole formed in the insulator corresponding to the bent portion, and is engaged by elastically urging the inner wall surface of the hole alternately in the width direction of the ribbon-shaped resistor. An air heater for an internal combustion engine, characterized in that the air heater is stopped.