JPS59206661A - Fuel heating system - Google Patents

Abstract

PURPOSE:To obtain a highly reliable fuel heating system by providing a junction communicating to the upper and down stream of a fuel pipe in the fuel feed path of Diesel engine while heat producing board and means at the enlarged portion between the junctions. CONSTITUTION: A conduit member 1 is formed by fastening the large diameter section of a funnel members 1a, 1b through a bolt 2. The first junction 3 is coupled to the upstream side of a fuel pipe while the second junction having small diameter is coupled to the downstream of the fuel pipe. A heat producing member 6 formed with heat producing material is provided in an enlarged section 5 formed between said junctions 3, 4. The heat producing member 6 is held through fastening force of the bolt 2 between the large diameter sections of said funnel members 1a, 1b. Galvanized electrode layers 7, 8 of such as Ni are applied on both faces of said member 6 to be fixed with an electrode board 10. Upon start of engine, voltage is applied to the heat producing board 6 to start heating of fuel effectively and to feed through a path 18 to a fuel filter.

Description

TECHNICAL FIELD The present invention relates to a device for heating fuel provided in a fuel supply passage of a diesel engine.

Technical background Diesel engine fuel has an environmental temperature of approximately -15°C.
If it is below this level, it will crystallize and the fluidity will decrease, which may cause clogging in areas with small flow path areas, such as fuel filters. When such a filter becomes clogged, the fuel supply condition deteriorates, making it difficult to start the engine, and even if it starts, the engine suddenly stops.

In order to avoid this problem, conventional fuel pipes heat the fuel within the fuel pipe by wrapping a coated heater or the like around the outer surface of the fuel pipe. However, with this structure, although the fuel near the tube wall can be sufficiently heated, the fuel in the center of the tube cannot be sufficiently heated. There are also fuel pipes in which the heater is inserted a considerable length into the pipe, but this makes it difficult to secure the heater within the pipe, and there is a risk that the heater may come off from the removed part during long-term use. , it is not sufficient in terms of reliability. Also in this case, only a portion of the fuel is heated as it is in contact with the heater surface, and sufficient heating is not achieved.

Purpose of the Invention In view of the above points, the present invention has been made with the object of providing a fuel heating device which has high structural reliability and is capable of sufficiently heating fuel.

Structure of the Invention The present invention provides first and second connecting portions that are attached to a fuel pipe for feeding fuel and communicate with the upstream and downstream sides of the fuel pipe, respectively. a conduit member having an enlarged portion formed between the contact portions; a conduit member formed from a heat-generating material and provided within the enlarged portion so as to be substantially perpendicular to the flow direction of the fuel; and the first and second connecting portions. It is characterized by comprising a heat generating means for causing the heat generating plate to generate heat.

Example The present invention will be explained below with reference to illustrated embodiments.

1 to 4 show an embodiment of the present invention, in which a pipe member 1
is the large diameter side of the two funnel-shaped members 1a and lb.
It is formed by fastening with several bolts 2. A small-diameter first connection part 34 located at the top of the figure is connected to the upstream side of a fuel pipe (not shown), and a small-diameter second connection part 4 located at the bottom is connected to the downstream side of the fuel pipe. be done.

A heat generating plate 6 formed from a heat generating material is provided within the enlarged portion 5 formed between the first and second connecting portions 3 and 4. The heating plate 6 contains a crystalline resin, such as polyvinylidene fluoride, which has a sandwiching property between the large diameter portions of the funnel members la and ``1b'' due to the fastening force of the poles 1 and 2. In other words, the heating plate 6 has a temperature ) The electrical resistance R shows a change as shown in FIG. contains epoxy resin as a reinforcing material in addition to crystalline resin and conductive material.
In the base material whose diameter is larger than that of O-rings 16 and 17,
To reduce heat generation, it is preferable to reduce or omit the conductive material. N on both sides of the heat generating plate 6
It is covered with electrode plating layers 7 and 8 such as i, and an electrode plate 10 is fixed to these plating layers 7 and 8 via screws 9, respectively. For example, the wire 11 connected to a DC 12V power source (not shown) has a core wire 12 exposed at its tip, and a part of the electrode plate 10 is fixed to the core wire 12 by caulking. This caulked portion is covered with a heat shrinkable tube 13 or the like. The vicinity of the electrode plate 10 of the funnel members 1a, lb is a raised part 14 in order to avoid contact with the electrode plate 10 and the hissing member 9, and an insulating member 15 is attached to the inner surface of the raised part 14.

O-rings 16 and 17 are sandwiched between the upper surface of the heating plate 6 and the funnel member 1a, and between the funnel member 1b and the lower surface of the heating plate 6, respectively. As a result, the inside of the conduit member 1 is cut off from the outside. O-rings 16 and 17 of heat generating plate 6
A plurality of passages 18 are bored closer to the inner circumference. This passage 18 allows communication between the first and second connecting portions 3 and 4,
The fuel flowing into the first connection part 3 along the arrow A flows through the passage 18.
It flows out from the second connection part 4 through.

Note that the surrounding area 6a of the poles 1 and 2 on the surface of the heat generating plate 6 is as follows:
After plating, it is cut with an end mill or the like, and the electrode plating layer is removed to improve insulation with respect to the bolt 2.

Although the device of this embodiment having the above configuration can be installed anywhere in the fuel pipe, the effect is remarkable when it is installed immediately upstream of the fuel filter. It is preferable to set the timing for turning on the power so that it is turned on at the same time as the engine key switch, for example. When the engine starts, a voltage is applied to the heat generating plate 6 and it begins to generate heat. Substantially all of the fuel passing through the fuel pipe flows while contacting the heat generating plate 6, is effectively heated, and is sent to the fuel filter. be done. therefore,
Fuel crystallization is prevented, filter clogging is prevented, and engine startability is improved.

Since the heat generating plate 6 has PTC characteristics, there is no fear that the fuel temperature will rise abnormally. The power supply to the heat generating plate 6 may be stopped in accordance with a signal of the fuel temperature or the outside temperature.

Note that if the entire mounting portion of the heat generating plate 6 and the lead wires 11 is coated with, for example, fluororesin, fuel will not penetrate into the heat generating plate 6, and the insulation resistance, salt contact resistance, etc. of the mounting portion will be improved. will improve.

Also, if the infundibulum is lunar 1a, lb, it is not necessarily holt 2.
It is not necessary to fasten them together, but these outer peripheral parts may be fastened together by caulking.

Furthermore, if the inner circumferential surface of the enlarged portion 5 is coated with a heat insulating material such as Teflon, the heat insulation properties will be improved and the heating efficiency of the fuel will be improved.

Effects of the Invention As described above, according to the present invention, a fuel heating device that can quickly heat fuel and has high reliability can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an embodiment of the present invention, Fig. 2 is a graph showing the electrical resistance characteristics of a heating element, Fig. 3 is a partially cutaway plan view of Fig. 1, and Fig. 4. is a sectional view taken along line IV-1v in FIG. 3; DESCRIPTION OF SYMBOLS 1... Pipeline member, 3... First connection part, 4... Second
Connection part, 5... Enlarged part, 6... Heat generating plate, 7, 8...
・Electrode plated eyebrow, 11... Lead wire, 18... Passage. Patent applicant Toyota Motor Corporation Patent agent Akira Aoki Patent attorney Kazuyuki Nishidate Patent attorney Kyosuke Donakayama Patent attorney Akira Yamaguchi Figure 1 Figure 2

Claims (1)

[Scope of Claims] (1) First and second connecting portions are provided that are attached to a fuel pipe that supplies fuel and communicate with the upstream and downstream sides of the fuel pipe, respectively, and the first and second connecting portions are provided. a conduit member having an enlarged portion formed between the connecting portions; and a conduit member molded from a heat-generating material and provided within the expanded portion so as to be substantially orthogonal to the flow direction of the fuel, and between the first and second connecting portions. A fuel heating device comprising: a heat generating plate in which a passage is formed to communicate with the heat generating plate; and a heat generating means for causing the heat generating plate to generate heat. 2. The heat generating plate is a conductive plate-like member having a positive polarity characteristic, and the heat generating means is an electrode plating layer coated on both sides of the heat generating plate described in 2. I=
2. The fuel heating device according to claim 1, wherein the lead wires numbered J and a power source for applying voltage to the heating plate via these lead wires are connected to each other.