JPS58162757A - Heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid heating device↑No, there is no practical use, but there is a book specifically related to a liquid fuel heating device for internal combustion engines.

Liquid fuel is composed of many components, and although these components are liquid at room temperature, they can freeze at low temperatures. Frozen fuel debris can cause blockages in engine fuel systems, particularly diesel engine fuel systems. The reason for this is that the diesel fuel system incorporates one or more fine filters whose purpose is to trap small particles of dirt in order to minimize damage to the operating surfaces of the fuel filter. Frozen particles of fuel are captured by the filter and gradually accumulate there, thereby inhibiting the supply of fuel to the engine.

It is a known fact that electric heating devices are used to heat fuel, and one example of such a device is described in U.S. Pat.
1265. In this case, the heating device is placed in the channels through which the fuel passes before reaching the filter. The heating device described in the above specification comprises a heating device having a pair of resistors in which tll pulses of power are consumed and a pair of e-war transistors each controlling the current in the resistors. Further, a control transistor and a temperature responsive device are attached to the heating device, and each of the casing parts is immersed in the fuel flowing through the fuel tank.

The disadvantage of this device is that the surface area of the heating component is very small.1. Another point is that the temperature of the parts must be raised considerably in order to perform rapid heating. Therefore, if the fuel in the channels should become empty, there remains a problem in that the surface temperature of the parts may rise too much, causing a dangerous breakdown.

Another drawback is the fact that since the fuel is in contact with the electrical components, it is necessary to select electrical components that can withstand the fuel and the substances it contains, such as water.

It is an object of the invention to provide a simple and convenient type of solvent heating device.

According to the invention, the fuel heating device Vi comprises a metal body with a substantially flat surface, a flow path for the liquid to be heated which is defined by at least a part of the metal body, and a supporting electrically insulating plate mounted on it. A foil-like electric heating element, a clamping plate, and an insulating plate are arranged opposite to the clamping plate, a silk-like heating element is attached to the above-mentioned surface of the metal body, and an electrical connection is made between the heating element and the above-mentioned surface. It consists of a means for fixing the clamping plate to a metal body in a state in which an insulating sheet is placed, and when the element is connected to a power source, heat generated within the element is conducted to the metal body and the liquid in the flow path is The thickness and material of the insulating sheet are determined so as to be heated.8 The present invention will be described in detail below with reference to the accompanying drawings.

According to Figures 1 to 5 of the drawings, the device, indicated generally at 10, consists of a composite body formed from two rectangular slabs made entirely of 1/@f, such as aluminum alloy. be done. The surface of the slab 110 is divided by gaskets 12 made of a material 1 that is resistant to heat and heated liquids. The problem surfaces of the two slabs of material have a portion of a flow path formed therein as shown in FIG. 6, the flow path being indicated at 161. Each channel is designed to be long, and one end thereof is connected to another channel through an opening 14. The other end of the flow path is another through opening i4
Although the flow path ends slightly before A, both channels communicate with each other through a flow opening 15 formed in the gasket. The gasket has an opening that corresponds to opening 14, and each opening within the gasket is made undersized. The opening 14 in the slab that communicates with the flow path is a plug 16.
is inserted inside.

The plug 16 is in the form of a bolt with a hexagonal head and a threaded shank which, in use, can be screwed into a mounting screw hole cut in, for example, a filter housing or a special mounting partner.

An enlarged diameter portion 17 is provided on the shank of the bolt between both ends of the bolt, and upon completion of assembly, the enlarged diameter portion abuts against the edge of each opening in the gasket 11 and serves as a seal. Blind holes are drilled from both ends of the bolt, and these open from the I-doshank portions on both sides of the enlarged diameter portion 170 to the circumferential surface. In use, these blind holes communicate with the fuel passages of the filter, allowing fuel to flow through the passage 16 of one slab 11 via the opening i5 of the gasket 12 and the passage 13 of the other slab. It looks like this. In use, the strands in an interpolating relationship with the strand 16 pass through the other opening 14 as well as through the opening in the slab, but this is only for convenience.

An improved version of the slab is shown at 40 in FIG. In this structure, the shape of the channel 41 is slightly different, but the basic difference compared to the example shown in FIG. 6 is that both ends of the channel communicate with the opening 14, respectively.

In this example, the opening 15 with the gasket 12 is not provided. In this case, bolts 16 are used for the pair of openings,
For another pair of openings, it is possible to obtain the same flow conditions as described above by using a bolt having a shank portion with a clearance around the opening of the gasket. This type of flow can be considered serial flow since the channels 16 are coupled in series. It is also possible to create parallel flows by using two bolts with a slightly different construction than described above. For parallel flow, each bolt has a blind hole that communicates with two holes on either side of the gasket. One bolt forms a fuel inlet', the fuel flow being divided by a channel 16.

The other bolt forms a fuel outlet, two holes receive fuel from the flow path, and a blind hole in the fuel bolt,
We'll meet up at

Although this device is designed to be attached to a filter unit, it is of course possible to attach it to another attachment point. Utilizing bolts of other shapes allows series or parallel flow to be achieved without fundamentally changing the equipment.

Each slab 11 has a flat surface 18 which is arranged to be set back from the outer surface of the slab. Both halves 1°
8 are fitted with a pair of electrically insulating sheets 19 of sufficient thickness and of a material capable of transferring heat from the heating element mounted on the supporting electrically insulating plate 20 to the associated plane 18. The plate is conveniently formed of an insulating laminate material of the type used in bullet circuit construction and has a foil electrical heating element shown at 21 in FIG. The heating elements are elongated and can be formed using conventional printed circuit techniques. The grate 20 has a protrusion 22 on which an electrical terminal 26 for connection to a power supply circuit as shown can be provided.

Sheet 19 can be made of nylon reinforced with glass fiber reinforced silicoglass, or if unreinforced it can be made of nylon coated with silicone grease.

A metal clamping seat 24 is applied to the outer surface of the plate 2° and the various parts are held in the assembled condition by fastening means in the form of ports 25 passing through responsive openings in the various parts.

In the example shown in FIGS. 1 and 2, a pair of power transistors 26 are each mounted on a slab and a plate 2
electrically coupled to a printed circuit on 0.

A drill hole is drilled in one of the slabs 11 to accommodate a temperature sensor 27, and the device is enclosed by a cover 28. The cover is provided with an opening to allow electrical connection to the terminal 23.

In use, the device is installed in the fuel system upstream of the filter, and when power is applied, it heats the fuel to prevent the risk of filter blockage due to frozen debris in cold weather.

In the unlikely event that the control circuit that communicates with the transistor fails, some means of preventing overheating of the slab material is required. If the transistor remains switched on, it is necessary to ensure that the heating element is shut off when the temperature reaches an overheating condition.

There are two ways to do this. The first method utilizes the expansion of the steel foil forming the heating element. Once overheating is reached, the foil expands and buckles; once buckling occurs, the temperature in this part of the heating element increases enough to cause a rupture, which interrupts the electrical circuit of the heating element. Ru. It is advisable to provide the heating element with a special part that is small in width and therefore has a small current capacity. This portion, indicated at 29 in FIG. 2, is advantageously formed on the protruding portion 22 of the plate.

As an alternative to utilizing buckling of the heating element, sheet 19 may be formed from a thermoplastic material such as nylon having a suitably low melting point. In this case, when the temperature of the heating element rises above the preset temperature, the plastic material melts and the heating element presses against the slab 11. A potential difference is created between the heating element and the slab over the entire length of the heating element, and when such contact occurs, a temperature rise occurs and the element breaks, resulting in the interruption of the conductive path of the element. It is possible to arrange it as follows.

Temperature sensor 27 is mounted in the slab near transistor 26, which is itself mounted in the slab and undergoes heating due to the passage of current. This allows for temperature regulation of the fuel leaving the heating device.
Fuel temperature can be controlled within 1°C.

Referring to FIG. 6, two heating elements are connected in parallel in the circuit, the conduction of the power transistor is controlled by a control circuit 30, one terminal of which is coupled to the negative power supply terminal 31, and the heating The element is coupled to a positive power supply terminal 64 via a switch 62 and a fuse 63. In the unlikely event that a failure occurs in the control circuit 60 and the sheet 19 melts, the fuse 6 will close before the heating element itself melts.
The fuse can be selected so that 6 is fused. However, it will be appreciated that once the heating element ruptures in this way, it will not be able to be used again. As can be seen in FIG. 6, two alarm lamps are provided, the first lamp 65 being coupled between the terminals 31 and the terminals of the switch 52 which is coupled to the heating element, and the second lamp 36
is coupled to an intermediate point between the control circuit 30 and the heating element and to a positive power terminal 67 which is itself coupled to the vehicle accumulator positive power terminal via a standard vehicle control switch. Control circuit 5 with control switch closed
If the temperature of the fuel detected by the sensor 27, which forms part of the 0, is lower than a preset value, the lamp 66 is turned on.

This is a command signal to the driver of the car to close the switch 62, and when the switch is closed, the lamp 65 lights up. Both lamps remain on until the fuel temperature reaches the desired value, at which point lamp 66 goes out and switch 32 is turned off at the will of the vehicle operator.
Just open it.

If desired, the power transistors may be controlled by a separate control circuit 30, in which case two alarm lamps corresponding to lamp 66 may be provided. Both control circuits can be set to operate at different temperatures, so that both heating elements are operated simultaneously only when the fuel is very cold.

Another structure uses a thermostat in place of the power transistor. The thermostat is located on the protrusion 22 of each freight.
and has a surface that maintains good thermal contact with the associated slab. Control of the fuel temperature using this control method is less accurate and less costly and does not require a separate housing for the control circuitry. A temperature responsive fuse may be provided in series with the heating element and the thermostat, and the temperature setpoints of the thermostat may be set to separate values.

The cover 28 is filled with epoxy or similar material.
Engineering from K. , 5゜□Wow. B. The compound fills every space within the cover and holds the transistor and thermostat in place.

[Brief explanation of drawings]

FIG. 1 is an exploded arrangement diagram of this device. FIG. 2 is a front view of a portion of the apparatus shown in FIG. FIG. 6 is the same front view as FIG. 2 of another part of the apparatus shown in FIG. 1; Fourth
The figure is a partial cross-sectional view of a portion of the apparatus shown in FIG. 1. Fifth
The figure is the same front view as FIG. 2 of another part of the apparatus shown in FIG. FIG. 6 is an electrical circuit diagram illustrating one method of coupling the apparatus to the engine electrical system. And FIG. 7 is a drawing similar to FIG. 6 showing another structure. (Symbols in the diagram) 10...Equipment, 11.Old...Slab, 12...
...Gasket, 16...Flow path, 14...
...Through opening, 15... Channel opening, 1
6... Plug, 17... Expanded diameter part, 1
8...Surface, 19. Old insulation sheet, 20.
...Flate, 21...Foil electric heating element, 22...Protrusion, 26...
Electrical terminal, 24...Metal clamping sheet, 2
5... Volt, 26... Power transistor, 27... Temperature sensor, 28...
...Cover, 29...Narrowing part, 60...
・Control circuit, 31...Negative power supply terminal, 62...
...Switch, 63...Fuse, 64...
...Positive power supply terminal, 65...First lamp, 6
6...Second lamp, 67/curved ball power terminal, FIG, 3. FIG, d, FIG5゜+V

Claims (1)

[Scope of Claims] 1) A metal body, a flow path with a heated liquid limited by a part of the metal body, a foil electric heating element attached on a supporting electric insulating plate, a clamping plate, and an insulating The clamping plate is placed in a position opposite to the clamping plate, a foil heating element is placed on the surface of the metal body, and an electrically insulating sheet is placed between the heating element and the metal body. The thickness and material of the insulating sheet are determined so that when the element is connected to a power source, the heat generated within the element is conducted to the metal body and heats the fluid in the flow path. A liquid heating device that is referred to as I￥f*. 2) The above-mentioned metal body is composed of a device having two roughly rectangular slabs, and a gasket placed between the upper slabs, each slab forming a surface that abuts the gasket, and forming a flow path. and the remainder of the flow path is defined by the adjacent face of the gasket, each slab having an associated foil electrical heating element mounted on a supporting insulating plate, with a clamping plate and an electrical insulating sheet between the heating element and the slab. 2. A heating device as claimed in claim 1, characterized in that the parts are secured in mutual assembly by means of a gel which extends through the openings of the parts. 6) each slab has a through opening communicating with one end of each channel, said opening being aligned to permit penetration of the quilt;
3. A heating device as claimed in claim 2, characterized in that the gasket has an opening therein which is aligned with and smaller than the dimension of the opening in the slab. 4) The gasket is provided with a flow path opening, and the flow path opening functions to provide the other end of the flow path that communicates with each other. heating device. 5) Each slab has another through-opening communicating with the other end of each channel, the opening on said side being aligned to allow for passage of the zelt, and the gasket itself having another through-opening in the slab. 7. The heating device according to claim 6, further comprising an opening that is aligned with the opening and has a size smaller than that of the opening. 6) If! to have temperature responsive means to control the current in the heating element! The heating device according to claim 5, wherein the heating device has the f-character. 7) The means comprises a nower transistor and a control circuit for the nower transistor, the control circuit comprising a temperature sensor responsive to the temperature of one of the slabs. The heating device described in . 8) The foil-shaped heating element has a constricted portion, and the constricted portion is designed to melt and break when an electrical failure occurs. heating device. 9) The temperature responsive means comprises a thermostat in communication with each of the heating elements in the circuit, and the thermostat has a surface that maintains good thermal conductivity with each slab. 10) The thermostat 8. The heating device according to claim 7, wherein the heating device has different temperature setting values. 11) A heating device according to claim 9, characterized in that it has a temperature-responsive fuse in the circuit communicating with the heating element. 12) The Zelto has an enlarged diameter portion formed in its central shank portion, the enlarged diameter portion cooperates with the periphery of the opening to form a seal, and the Zelto is bored inward from both ends. Claim 4, characterized in that a blind hole is provided, a passage communicating with the blind hole is provided in the shank portion, and an opening is provided on the circumferential surface of the shank portion of the enlarged diameter portion.
The heating device according to item 1 or 5. 16) Percentage Based on claim 5, there is another gel disposed in the opening on the side, and the diameter of the shank of the gel is larger than the diameter of the other opening in the gasket. 13. The heating device according to claim 12, characterized in that it is small. 14) The bolt and another bolt in the opening on the side have a diameter smaller than the diameter of the opening in the gasket, and each of the delts is connected to a hole on the circumferential surface of the shank on both sides of the gasket. 6. The heating device according to claim 5, further comprising a through hole. 15) A liquid heating device constructed by the combination and arrangement of the parts described above with reference to the accompanying drawings.