JPS6218694Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an air heater device installed in a curved intake passage, such as a connecting portion between an intake duct and an intake manifold of an internal combustion engine.

2. Description of the Related Art In diesel engines and the like, it is known to interpose an air heater in the middle of an intake passage in order to warm the air taken into the engine and improve ignitability.

In this case, if you install an air heater at the part where the intake passage is curved, that is, at the connection between the intake duct and intake manifold, more of the intake airflow will flow toward the outer circumference of the curved part, increasing the heat exchange rate at the outer part. On the other hand, the efficiency on the inner circumferential side is poor, and the disadvantage is that the heating wire of the air heater increases intake resistance.

Therefore, the applicant has proposed an air heater device in Utility Model Application No. 114168/1982 in which, in the curved portion of the intake passage, a heater wire is attached only to the outer periphery, with the inside being a simple passage. This makes effective use of the heat generated by the air heater, particularly in operating ranges where intake heating is required, such as at engine start-up, while reducing intake resistance as much as possible when the amount of intake air increases, such as in the high engine speed range.

However, when such an air heater device is assembled into an internal combustion engine, if it is installed in the wrong direction at the connection between the intake duct and intake manifold, it will not only not be able to perform its intended function, but may even work in the opposite direction. As heating efficiency deteriorates, careful assembly work was required.

This reduces the efficiency of assembly work,
It was also very unfavorable from a quality control standpoint.

The present invention was proposed in order to solve this problem, and while a protrusion is provided on a part of the air heater to which a part of the heater wire is stretched, the intake duct (air heater housing) that sandwiches the air heater is
By providing a portion on each mating surface between the air heater and the intake manifold that accepts the protrusion only when the air heater is in the correct assembly position, and otherwise interferes with the protrusion, incorrect assembly of the air heater with a certain mounting direction is prevented. The purpose is to prevent it easily and reliably.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIGS. 1 and 2, 1 and 2 indicate an air housing (intake duct) and an intake manifold that constitute a part of the intake passage.

Reference numeral 3 denotes an air heater inserted between the joint surface of the air housing 1 and the intake manifold 2, and a heater wire 5 is disposed in the guide frame 4 only in the outer half of the curved portion of the intake passage. Ru.

A plurality of heater wires 5 are arranged in parallel orthogonally to the line connecting the outer circumferential side and the inner circumferential side, and heat the intake air and produce a rectifying effect.

6A and 6B are terminals connected to the heater wire 5.

As shown in FIGS. 3A to 3D, pins 7 are provided as protrusions at the corners of the upper surface of the guide frame 4. A receiving part (recess) 8 that accepts this pin 7 only when
is formed at the corner of the joint surface of the air housing 1, and at the corner opposite to the receiving part 8, there is a pin 7 that will come into contact with the pin 7 when the air heater 3 is vertically correct but the horizontal direction is reversed. An interference portion (built-up portion) 9 is formed that makes assembly impossible.

In addition, there is an interference part on the joint surface of the intake manifold 2 that does not interfere when the air heater 3 is oriented in the correct vertical direction, but comes into contact with the pin 7 in both left and right directions when the front and back directions are reversed. 10A and 10B are formed at diagonal corners.

As a result, the air heater 3 is inserted into the joint surface of the air housing 1 and the intake manifold 2, and the bolt holes 11A and 1 provided at the four corners are inserted.
When fastening with the through bolt 12 via 1B and 11C, unless the air heater 3 is in the correct assembly position, the pin 7 will interfere with one of the joint surfaces, which may result in incorrect assembly. It becomes possible.

Therefore, when the pin 7 of the air heater 3 comes into contact with the pin 7 of the air heater 3, the assembly worker should turn it inside out or reverse the left and right sides to make sure that the joint surfaces of the air heater 3, air housing 1, and intake manifold 2 are tight. As long as the through bolts 11 are tightened when they match, the air heater 3 can be installed correctly, and there is no need to check whether it is correct or not.

As described above, according to the present invention, it is possible to assemble the air heater in the correct position extremely easily and reliably, thereby facilitating the assembly work and improving accuracy.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing an embodiment of the present invention, Fig. 2 is a sectional view, Fig. 3A is a bottom view of the joint of the air heater housing, Fig. 3B is a plan view of the air heater, Fig. 3C Similarly, FIG. 3D is a bottom view thereof, and FIG. 3D is a plan view of the joint portion of the intake manifold. 1... Air housing (intake passage), 2... Intake manifold (intake passage), 3... Air heater, 5... Heater wire, 7... Pin (protrusion),
8... Acceptance section, 9, 10A, 10B... Interference section.

Claims (1)

[Scope of utility model registration request] In an air heater device in which an air heater is interposed in a curved intake passage, and the heater wire of the air heater is arranged biased toward the outer circumferential side of the curved portion, a protrusion is provided on one surface of the guide frame of the air heater, while the air heater is held between the air heaters. An air heater device characterized in that each joint surface of an intake passage is provided with a receiving part and an interference part, respectively, which receive the protrusion when the air heater is in the normal assembly position, and which interfere with the protrusion at other times.