WO2016023752A1

WO2016023752A1 - Rail assembly having fuel heater

Info

Publication number: WO2016023752A1
Application number: PCT/EP2015/067385
Authority: WO
Inventors: Andreas Reissner; Conrad Bubeck
Original assignee: Robert Bosch Gmbh
Priority date: 2014-08-12
Filing date: 2015-07-29
Publication date: 2016-02-18
Also published as: EP3180508A1; BR112017002452A2; DE102014215981A1

Abstract

The invention relates to a rail assembly (1; 4; 6; 7), comprising a chamber (11; 41, 61, 71) made of a steel material, a fuel heater (12; 42; 52; 62; 72) having an annealing tube (121; 421; 521; 621; 721), and a receiving component (13; 23; 33; 43; 63; 73) provided in an opening (112; 412; 612; 712) of the chamber (11; 41, 61, 71) for receiving the fuel heater (12; 42; 52; 62; 72), wherein the annealing tube (121; 421; 521; 621) of the fuel heater (12; 42; 52; 62; 72) is directly accommodated in the receiving component (13; 23; 33; 43; 63; 73). The invention further relates to an internal combustion engine having such a rail assembly (1; 4; 6; 7), wherein the internal combustion engine is configured to operate with alcohol, preferably methanol or ethanol, and gasoline, or an alcohol mixture and a mixture of alcohol and gasoline.

Description

Rail assembly with fuel heater

State of the art

The present invention relates to a rail assembly with a fuel heater, in particular a rail assembly of a fuel rail of an internal combustion engine for conducting alcohol or an alcohol mixture as fuel to the

Internal combustion engine.

For the automotive sector, there are countries, such as Brazil or USA, in which in addition to conventional gasoline and alcohol, that is mainly methanol or ethanol, or alcohol-gasoline mixtures are used to operate internal combustion engines. Such alcohols can be locally produced in these countries, making them independent of oil imports and thereby making operating an internal combustion engine with alcohol in these countries much cheaper than operating the oil

Internal combustion engine with gasoline or diesel fuel is.

However, operating internal combustion engines with alcohol or alcohol mixtures can also be disadvantageous since, for example, ethanol-operated gasoline engines can only be started at a temperature of more than 14 ° C. Their operation is therefore at lower, cold

Temperatures quite difficult. At present, this fact is taken into account by adding fuel tanks in addition to the main tank, which is filled with alcohol, in motor vehicles powered by alcohol

Lines is provided, which is filled with regular gasoline. At temperatures below 14 ° C, the gasoline engine is started not with alcohol but with gasoline until the engine has reached a certain temperature, after which it can be switched to alcohol operation with alcohol from the main tank. These Additional tank solution is still widespread in alcohol-powered gasoline engines.

However, a major disadvantage of this additional tank solution is attributable to the fact that the contents of the additional tank and the associated

Lines, that is, the gasoline, in warm temperatures above 14 ° C, as they are available in summer, is not used and over time largely

evaporates, causing the remaining residual gas in pipes and tank

becomes thick. In this thickening of the gasoline, however, long-chain hydrocarbons remain, which can inter alia stick the outlet of the additional tank and the subsequent valves and lines. Is it

then, in the winter, getting colder again, starting with gasoline in this case is due to the glued pipes / valves and thereby clogged

Additional tanks no longer possible. The pipes and the additional tank to

Storage of gasoline must be intensively cleaned or in this case

worst case even be completely replaced. Beside this

Another major disadvantage of the auxiliary tank solution is that for this solution in a motor vehicle two tanks, that is to say the main tank filled with alcohol and the additional tank filled with alcohol, must be provided, which require more space than just a single tank in the vehicle. making the vehicle overall in terms of manufacturing and

Component installation is more expensive. In addition, the gasoline filled

Additional tank in an accident of the motor vehicle is a non-negligible additional security risk.

In order to find an alternative to the additional tank solution, it is already known in the field of alcohol-powered internal combustion engines to omit the additional tank with all its disadvantages and instead to use a heatable fuel rail, in which the supplied alcohol can be heated at low temperatures. A specially designed for this purpose Rail, an associated

Fuel heater, a dedicated special controller and its

Software control is a heated fuel rail system, the so-called Flexstart system. So far, at least two such Flexstart systems are known, which differ by the material of the rail, wherein the rail consists of either steel or a plastic. The used fuel heater of the each Flexstart system is usually the same in both cases, with only the connection technology of the fuel heater in the rail and the housing of the fuel heater for the respective rail must be designed differently. As an example of a corresponding fuel heater for such a Flexstart

For example, DE 10 2006 052 634 A1 proposes a fuel heater which is used as a heating source and which is integrated into the ethanol injection system and serves to preheat the fuel. The basic structure of the fuel heater used corresponds to that of known metallic glow plugs, as they are known inter alia from DE 20 2005 016 047 U1.

As shown in FIG. 8, such a fuel heater 8 is shown in FIG

Essentially a closed, tubular formed metallic glow tube 81, in which a spiral-shaped heating coil (not shown) installed and materially connected to the glow tube 81, for example, is welded. At the other end, the heating coil is electrically conductively connected to a connecting bolt (not shown), at the end of which the electrical connection in the form of a

Round plug 82 is located. A ceramic insulating powder in which it is

Usually is magnesium oxide, is used in the glow tube 81 between the turns of the spiral-shaped heating coil as electrical insulation against the glow tube 81. Glührohr 81, heating coil, insulating powder and

Connecting bolts form the radiator. The radiator sits in a housing 83 made of steel, which in turn is screwed into a chamber 9 of the Flexstart Rails. This seated in the housing 83 part of the radiator is pressed in an assembly in the housing 83, wherein between the housing 83 and the round plug 82, an insulating 84 is installed, which the connecting bolt and the

Round plug 82 isolated from the housing. The fuel heater 8 is screwed through the housing 83 in a receiving member 91, which in turn sits in an opening of the rail 9, wherein a seal geometry 85 between the rail 9 and the housing 83 of a seal geometry of a known glow plug

taken over and over two cones with different angles, as can be taken, inter alia, the standard DIN ISO 6550-2. In operation, cold fuel passes from a main rail (not shown) via a fuel inlet 92 into a chamber 93 in which the fuel is heated by the fuel heater 8 and then rises. The warm fuel accumulates in front of a fuel outlet 94 of the intermediate rail 9, behind which an injection valve (not shown) that ultimately injects the warm alcohol fuel into an intake manifold of the internal combustion engine for combustion thereof. The Flexstartsystem can also be used in conjunction with a gasoline direct injection. A problem of the alternative solution described above, however, is that the

Requirements for the tightness of the Flexstart system are much higher than for the installation systems of conventional glow plugs, as can be taken from the standard DIN ISO 7578, for example. A leakage allowed there is too high for the Flexstart system, since both the tightness of the press fit between glow tube 81 and housing 83 of the fuel heater 8 as well as the tightness of the

Sealing seat between the fuel heater 8 and the receiving member 91 of the rail 9 of geometrical tolerances and the quality of the respective surfaces are dependent. The conical seat between fuel heater 8 and 9 rail in the form of a

Cone cone is comparatively more prone to leak than the interference fit between glow tube 81 and housing 83 of the fuel heater. 8

Disclosure of the invention

According to the present invention, a rail assembly with the features of claim 1 is proposed, preferably for an internal combustion engine for

Burning alcohol as fuel. More specifically, the

Rail assembly according to the invention a chamber made of a steel material, also known as a rail chamber or fuel rail chamber, a fuel heater with a glow tube and provided in an opening of the chamber

Receiving member, wherein the receiving member for receiving the

Fuel heater is provided to project this into the chamber

to let. The glow tube of the fuel heater is according to the invention in the

Receiving member recorded directly, so without a further component between the glow tube and receiving member is provided. Accordingly, that stands

Glow tube of the fuel heater directly in contact with the receiving component,

on the one hand cost-effective to dispense with other components such as the housing of a known fuel heater as described above, and on the other hand, the disadvantages of the previously described

disadvantageous conical seat between the known fuel heater and the chamber can be avoided. The object of the present invention, at least To make one of the critical sealing interfaces superfluous, in particular the conical sealing seat, is correspondingly fulfilled with the rail assembly according to the invention. Advantageous developments of the invention are possible by the features of the dependent claims.

According to a preferred embodiment of the rail assembly according to the invention, the glow tube of the fuel heater is provided in the receiving member pressed. The glow tube of the fuel heater is therefore no longer pressed into the housing but directly into the chamber, whereby the disadvantageous conical seat between glow tube and housing is avoided. Alternatively or additionally, the glow tube of the fuel heater may be materially connected to the receiving member, wherein the cohesive connection is preferably a welded joint or a solder joint. This means that the glow tube is not only pressed into the receiving component, but also can also be welded or soldered to it.

Alternatively, the glow tube can be pressed either only in the receiving member, wherein the press fit provides the desired tightness, but can also be "welded" or soldered without interference fit in this case, the interference fit no longer be completely tight It is sufficient a slight interference fit, the glow tube during the following

Mechanically holding the welding process. The desired tightness is produced by the weld.

A corresponding welded connection can be produced, for example, by drawing a fillet weld, for example with a laser, between the glow tube and the receiving component. With such

cohesive connection, it is generally possible, also the

Usually to avoid existing between the housing and rail sealing surface, so that accounts with the solution according to the invention all known from the prior art tightness problems. A leak test between the housing and the glow tube, which usually has to be carried out consistently in all rail assemblies of the prior art, thereby completely eliminated. According to an additional development of the present rail assembly according to the invention, a main body of the receiving component has a shape of an open hollow cylinder, that is, in an annular shape with a continuous opening, which is further preferably a central opening. The

Receiving member may have an outer diameter of 10 to 30mm, preferably in about 20mm, and a height of 6 to 30mm, preferably in about 12mm, the central opening may have a diameter of 4 to 8mm, preferably 6mm. The main body may be a solid body which is annular, but may alternatively be thin-walled, for example, with a wall thickness of 0.5 to 2mm, preferably 1mm, the main body has a cup shape by the thin-walled training, with an opening in the bottom of the pot, which in turn creates the open hollow cylindrical shape. Preferably, a

thin-walled extension provided on the main body of the receiving member, which serves for further contacting of the glow tube. The extension starts at an outer diameter of the opening in the main body, ie at the edge of the opening in the main body. The thin-walled extension preferably also has a shape of an open hollow cylinder, so it is also in a ring shape. The thin-walled extension of the receiving component essentially serves to facilitate the production of the cohesive connection between the glow tube of the fuel heater and receiving component, for example, by welding together these components directly through the thin-walled extension and this is thus directly connected to the glow tube. For laser welding, for example, this has the advantage that the laser is not exactly at the edges of the two

Components, ie the glow tube and the receiving component must meet but a margin for the welding accuracy is given, which can have a very favorable effect on subsequent tolerance requirements. Further preferably, the thin-walled extension of the chamber is provided pioneering, so arranged on the main body, that the extension increases the axial extent of the receiving member. Especially with this

Embodiment, the previously described welding together of the glow tube to the receiving member can be facilitated. Alternatively, the extension may also be provided to the chamber indicative of the main body. However, this embodiment is only useful if the main body is thin-walled and the extension thereby into the inner cavity of the main body

protruding, whereby a unilaterally open, continuous annular shape is formed, which shows an approximately U-shaped cross-section, as will be described in more detail below with regard to the preferred embodiments.

According to an additional development of the rail assembly according to the invention, the receiving member is a rotated component, that is, a manufactured by a turning process component, a deep-drawn component, ie a through

Deep-drawn manufactured component, a extruded component, ie a manufactured by flow extrusion component or even by a

Combination of said production method manufactured component. The receiving member is preferably made of stainless steel, but may also be made of a similar material, as long as a connection with the existing of a stainless steel material chamber is possible. Stainless steel 1.4301 is currently used for the chamber. This material can basically also be used for the receiving part. For a

Thermoformed housing can be used stainless steel 1.4303 or 1 .4307. The glow tube may consist of a nickel-chromium alloy 2.4851. However, correspondingly corrosion-resistant stainless steels are also suitable, for example 1.4828.

According to an additional development of the rail assembly according to the invention, the fuel heater in addition to the glow tube with the inner

Heizwendel and the insulating powder further connected to the glow plug connecting bolt, more precisely connected to the heating coil of the glow tube connecting bolt, and a seal, wherein the end of the connecting bolt, which is not connected to the heating coil, from the

Glow tube protrudes and the seal between the protruding from the glow tube part of the connecting bolt and the receiving member is arranged and seals them to each other. This seal is used

In particular, in a press fit between the glow tube and receiving member to ensure the tightness of the press fit, or in cohesively connected glow tube as additional safety precaution in possible Leakage between glow tube and receiving member to serve. The

Receiving member can maintain the known from the prior art annular solid body with cone cone to provide a better recording of the seal between receiving member and glow tube. The seal may consist of hydrogenated acrylonitrile butadiene rubber (HNBR) or fluororubber (FKM).

Further preferably, in the previous development of the rail assembly according to the invention, the fuel heater in addition to the glow tube with the inner heating coil and the insulating powder, connected to the glow plug connecting bolt and the seal also have an insulating and a round plug or a round nut, the insulating between seal and round or round nut is arranged to prevent short circuits. The insulating washer is preferably made of an electrically non-conductive material, such as a plastic or the like. Round nut or round plug serve as a conclusion of the fuel heater at the protruding from the glow tube end of the

Terminal stud. A round nut, which should have a through bore with internal thread, is thereby screwed onto the free-standing end of the connecting bolt and caulked for fixing with this. For this, the connecting bolt must be provided with an external thread. It is alternatively also possible to use a round nut without internal thread, which is caulked only on the external thread of the connecting bolt. A round plug can also be screwed onto an external thread of the connecting bolt and caulked for fixing. An alternative possibility is to use the connecting bolt instead of a

To provide external thread with a knurl, in which case the round plug must also have no thread, as during the Verstemmvorgangs the round plug is simply pressed onto the connecting bolt. In all cases, the round plug or the round nut presses the insulating against the seal and / or the receiving member to ensure a tight cohesion of the individual components of the fuel heater.

According to a further aspect of the present invention, an internal combustion engine with a previously described rail Assembly proposed, wherein the internal combustion engine is designed for operation with alcohol, preferably methanol or ethanol, or an alcohol mixture. The operation of the internal combustion engine with gasoline or a

Mixture of gasoline and alcohol is also possible.

Advantages of the invention

With the rail assembly according to the invention, its components can be reduced compared to the prior art by up to three components, that is, depending on the design of the housing of the fuel heater per se, on a seal between the housing of the fuel heater and receiving member and a corresponding insulating disc are omitted, resulting in a huge cost savings. The glow tube of the fuel heater is no longer pressed into the housing but inserted directly into a chamber of the rail. As a result, the normally necessary thread and the necessary sealing cone surface of the sealing geometry can be dispensed with in the receiving component as a connecting piece between rail and fuel heater. This eliminates the problem-prone tapered seat, which can be further significant cost savings and significantly simplifies the entire structure of the rail assembly.

When the glow tube is welded, a cohesive material is created

Connection, which also eliminates the second sealing surface between the housing of the known fuel heater and the receiving member and thus all known leaks problems can be avoided.

Furthermore, with a rail assembly according to the invention eliminates the

Necessity of a leak test between the housing and the

Radiator in the course of a quality inspection, which is usually carried out at 100% of the rail fuel heater used.

Brief description of the drawings

Fig. 1 is a cross-sectional view of a first preferred embodiment of a rail assembly according to the invention; Fig. 2a is an enlarged cross-sectional view of a receiving member of the rail assembly shown in Fig. 1;

Fig. 2b is an enlarged cross-sectional view of a receiving member of a second preferred embodiment of a rail assembly according to the invention;

Fig. 3a is an enlarged cross-sectional view of a receiving member of a third preferred embodiment of a rail assembly according to the invention;

3b is an enlarged cross-sectional view of a receiving member of a fourth preferred embodiment of a rail assembly according to the invention;

Fig. 4 is a cross-sectional view of the fourth preferred embodiment of a rail assembly according to the invention with the receiving member shown in Figure 3b in the installed state.

Fig. 5 is a cross-sectional view of a fuel heater of the first

preferred embodiment with attached round plug;

Fig. 6 is a cross-sectional view of a fifth preferred embodiment of a rail assembly according to the invention;

Fig. 7 is a cross-sectional view of a sixth preferred

Embodiment of a rail assembly according to the invention; and

Fig. 8 is a cross-sectional view of a rail assembly according to the prior art.

Embodiments of the invention FIG. 1 shows a rail assembly 1 according to a first preferred embodiment

Embodiment in a partially sectioned cross-sectional view. The rail assembly 1 consists of a chamber 11, a fuel heater 12 and serving as a spacer receiving member 13. The chamber 11 has an interior 111 in which the fuel flows during operation, and an opening 112 in which the receiving member 13th is used, preferably fluid-tight soldered. The chamber 11 further includes a fuel supply 113 for supplying the fuel from a main rail into the interior 111 of the chamber 11 and a fuel discharge 114 for discharging the fuel heated by the fuel heater 12 to an injection valve (not shown). A fuel flow during operation of the rail assembly 1 is shown in Figure 1 by arrows. The fuel heater 12 has an incandescent tube 121, a

Connection bolt 122 and a circular connector 123, wherein the fuel heater 12 is inserted into a central through hole 132 of the annular receiving member 13. More specifically, the glow tube 121 of the

Fuel heater 12 in the central passage opening 132 of the

Receiving member 13 pressed and / or welded, creating a direct contact or a direct connection between the glow tube 121 and

Receiving member 13 is formed, which is fluid-tight. The glow tube 121 is constructed as in a known fuel heater with heating coil, etc. The glow tube

121 protrudes into the chamber 11 so as to be able to heat the fuel. The round plug 123 is connected to a free end of the connecting bolt

122 caulked and is used inter alia for electrically contacting the fuel heater 12. A ground connection via the metal chamber 1 1, which is connected to the main metal rail (not shown). The

Total trailer is attached to the engine block.

Figure 2a shows the receiving member 13 of the first preferred embodiment of the rail assembly according to the invention in an enlarged detail view in cross section. The receiving member 13 has a substantially annular shape and consists of a cylindrical main body 131 made of solid material with a central passage opening 132 into which the glow tube 121 is to be inserted. In this case, the glow tube 121 can be pressed into the central passage opening 132 and / or connected to it in a material-locking manner, for example by soldering or welding or the like, the passage opening 132 can alternatively for this purpose may also be provided decentrally in the main body 131, and may also be provided with an inclination in the main body 131, so that the glow tube 121 does not project straight but obliquely into the chamber 11

FIG. 2b shows a receiving component 23 of a second preferred embodiment

Embodiment of the rail assembly according to the invention. The receiving member 23 is substantially identical to the receiving member 13, with a cylindrical main body 231 made of solid material with central

Through hole 232, with the difference that the receiving member 23 also has a thin-walled extension 233, which is provided at an end face of the main body 231 so that the passage opening 232 is extended. The thin-walled extension 233 thereby forms a projection which serves to hold the glow tube 121 over a longer distance. Furthermore, when the glow tube 121 and the receiving component 23 are welded together, they can be welded directly through the thin-walled extension 233 and thus directly connected to the glow tube 121, whereby a firm, fluid-tight connection between the glow tube 121 and the receiving component 23 is created. In order to facilitate welding, the receiving member 23 should be inserted into the opening 112 of the chamber 11 so that the thin-walled extension 233 is directed away from the inner space 111 of the chamber 11. The thin-walled extension 233 is correspondingly advantageous in particular for welding. The welding directly through the thin-walled extension 233 has the advantage that a welding laser does not exactly match the edges of the two

must meet welding components. This has a very favorable effect on later tolerance requirements. It can also be both methods, ie

Pressing and welding, combined. In this case, the interference fit between glow tube 121 and through hole 232 no longer has to be tight. The tightness is produced by the weld.

FIG. 3 a shows a receiving component 33 of a third preferred embodiment

Embodiment of the rail assembly according to the invention. The main body 331 of the receiving member 33 is here also thin-walled, so that a pot shape is formed, in the bottom of a central through-hole 332 is provided, wherein the thin-walled main body 331 in a thin-walled Extension 333, which protrudes from the main body 331 away from the ground.

FIG. 3b shows a receiving component 43 of a fourth preferred embodiment

Embodiment of the rail assembly according to the invention. The main body 431 of the receiving member 43 is similar to that shown in Fig. 3a

Receiving member 33 also formed thin-walled, so that a pot shape is formed in the bottom of a central through-hole 432 is provided. The thin-walled main body 431 also merges into a thin-walled extension 433, which however differs from the main body shown in FIG. 3a

431 protrudes. FIG. 4 shows the fourth embodiment of the rail assembly 4 according to the invention in a partially sectioned cross-sectional view. The rail assembly 4 consists of a chamber 41, a fuel heater 42 and serving as a spacer receiving member 43. The chamber 41 has an interior space 411, in which the fuel flows during operation, and an opening 412, in which the receiving member 43rd soldered fluid tight. The fuel heater 42 has a glow tube 421, a connecting bolt 422 and a round plug 423, wherein the fuel heater 42 in the central

Through opening 432 of the cup-shaped receiving member 43 is inserted. More specifically, the glow tube 421 of the fuel heater 42 is press-fitted into the central through hole 432 of the receiving member 43, whereby a direct contact or a direct connection between the glow tube 421 and receiving member 43 is formed, which is fluid-tight. In Figure 4, therefore, the receiving member 43, which is deep-drawn or extruded here, shown in conjunction with the chamber 41 and the fuel heater 42 with mounted round plug 423.

The receiving components 33 and 43 shown in Figures 3a and 3b are deep-drawn or extruded, creating a cost advantage over the receiving components 13 and 23 shown in Figures 2a and 2b. The in FIG

3a receiving member 33 is optimized for welding. The weld is pulled through the thin-walled extension 333. In contrast, the receiving component 43 shown in FIG. 3b is more suitable for the pressing-in process, but it is also conceivable to weld the thin-walled extension 433 to the glow tube 421 via a fillet weld. Figure 5 shows a fuel heater 52 of the fifth embodiment of the rail assembly according to the invention in a partially cut

Cross-sectional view. The fuel heater 52 has a glow tube 521, a connection bolt 522 and a round plug 523. In the glow tube 521, a spiral-shaped heating coil 524 is installed and materially connected to the glow tube 521, for example, welded. At the other end, the heating coil 524 is electrically conductively connected to one end of the connecting bolt 522, at the other end of which the electrical connection in the form of the round plug 523 is located. A ceramic insulating powder 525, which is typically magnesium oxide, serves as an electrical insulation in the glow tube 521 between the turns of the helically shaped heating coil 524 opposite the glow tube 521. The connection bolt 522 is electrically insulated from the glow tube 521 by a radiator seal 526. The radiator seal 526 protects the interior and thus the

Heating coil from air and other pollutants, such as liquids, oil or other particles. The round plug 523 is the plug of

Similar to glow plugs and is also used in already known Flexstart systems. In this embodiment of the fuel heater 52 is dispensed with a housing seal and an insulating. The connecting bolt 522 is short and stiff enough to securely hold the round plug 523, which is caulked in a caulking region 5231 with the connecting bolt 522 provided with a knurling 5221 at the end. A connection via a thread is also conceivable here. The round plug 523 can only after the

Pressing the fuel heater 52 in a corresponding

Receiving member are connected to the connecting bolt 522. If the connection between the fuel heater 52 and the corresponding receiving component is realized by means of laser welding, the round plug 523 can already be pre-assembled.

FIG. 6 shows a rail assembly 6 according to a sixth preferred embodiment

Embodiment in a partially sectioned cross-sectional view. The rail assembly 6 consists of a chamber 61, a fuel heater 62 and serving as a spacer receiving member 63. The fuel heater 62 has a glow tube 621, a connecting bolt 622 and a round plug 623rd wherein the fuel heater 62 through the annular formed

Receiving member 63 protrudes. More specifically, the glow tube 621 of the fuel heater 62 is inserted into a central through hole 632 of the receiving member 63 provided in a main body 631. The round plug 623 is caulked to a free end of the terminal bolt 622 and serves inter alia to electrically contact the fuel heater 62. A ground connection is made via the metal chamber 61 which is connected to a metal main rail (not shown) which is secured to the engine block. The receiving member 63 of this embodiment retains the inner contour of a housing of a known fuel heater and is soldered into an opening 612 of the chamber 61 as previously described. Subsequently, the glow tube 621 is pressed into the receiving member 63. Between connecting pin 622 and receiving member 63, a seal 64 is provided, wherein the seal 64 is in the form of a cone and with a sealing cone geometry 633 of the receiving member 63 goes into abutment.

In addition, an insulating washer 65 made of an electrically non-conductive material, preferably plastic, between the circular connector 623 and the seal 64 is mounted. The round plug 623 may be caulked to the connecting bolt 622, as shown in Figure 5, or the

Round plug 623 can be screwed onto the connecting bolt 622 and

then be caulked for fixing with this, in which case the connecting bolt 622 must be provided with a thread. During the caulking process, the round plug 623 is pressed onto the insulating disk 65. FIG. 7 shows a rail assembly 7 according to a seventh preferred

Embodiment in a partially sectioned cross-sectional view. The rail assembly 7 differs from the rail assembly 6 shown in Figure 6 essentially only in that instead of a circular plug 623 a

Round nut 723 is provided. The rail assembly 7 thus consists of a chamber 71, a fuel heater 72 and serving as an intermediate piece

Receiving member 73. The fuel heater 72 has a glow tube 721, a connecting bolt 722 and the round nut 723, wherein the fuel heater 72 protrudes through the annular receiving member 73. The

Round nut 723 is preferably bolted to a free end of the connecting bolt 722. Alternatively, the round nut 723 without thread be provided, in which case the round nut 723 is caulked with the connecting bolt 722. Among other things, the round nut 723 serves to electrically contact the fuel heater 72. A ground connection is made via the metal chamber 71, which is connected to a metal main rail (not shown), which is fastened to the engine block. The receiving member 73 of this embodiment retains the inner contour of a housing of a known fuel heater and is soldered into an opening 712 of the chamber 71 as previously described. Subsequently, the glow tube 721 is pressed into the receiving member 73. Between terminal pin 722 and receiving member 73, a seal 74 is provided, wherein the seal 74 is in the form of a cone and with a sealing cone geometry 733 of the

Receiving member 73 goes into investment. In addition, an insulating washer 75 made of an electrically non-conductive material, preferably plastic, between the round nut 723 and the seal 74 is mounted.

The technical features of the embodiments described above are not limited to the respective embodiment and are correspondingly interchangeable.

Claims

claims

1. Rail module (1, 4, 6, 7), with

a chamber (11; 41, 61, 71) made of a steel material,

a fuel heater (12; 42; 52; 62; 72) having a glow tube (121; 421;

521; 621; 721), and

a receiving component (13; 23; 33; 43; 63; 73) provided in an opening (112; 412; 612; 712) of the chamber (11; 41, 61, 71) for

Receiving the fuel heater (12; 42; 52; 62; 72), wherein the glow tube (121; 421; 521; 621; 721) of the fuel heater (12; 42; 52; 62; 72) in the receiving member (13; 23; 33, 43, 63, 73) is recorded directly.

2. Rail assembly (1; 4; 6; 7) according to claim 1, wherein the glow tube (121;

421; 521; 621; 721) of the fuel heater (12; 42; 52; 62; 72) in the receiving member (13; 23; 33; 43; 63; 73) is pressed.

The rail assembly (1; 4; 6; 7) of claim 1 or 2, wherein the glow tube (121; 421; 521; 621; 721) of the fuel heater (12; 42; 52; 62; 72) is in communication with the receiving member (13; 23; 33; 43; 63; 73) is materially connected, wherein the integral connection preferably a

Welded joint or a solder joint is.

4. Rail assembly (1; 4; 6; 7) according to one of the preceding claims, wherein a main body (131; 231; 331; 431; 631; 731) of the

Receiving member (13; 23; 33; 43; 63; 73) has a shape of an open hollow cylinder, wherein the main body (331; 431) is preferably thin-walled.

5. Rail assembly (4) according to claim 4, wherein a thin-walled extension (233; 333; 433) on the main body (231; 331; 431) of

Receiving component (23; 33; 43) for contacting the glow tube (421) is provided, which preferably has a shape of an open hollow cylinder.

The rail assembly (4) according to claim 5, wherein the thin-walled extension (233; 333; 433) is provided facing away from the chamber (41) or facing the chamber (41) on the main body (231; 331; 431).

A rail assembly (1; 4; 6; 7) according to any one of the preceding claims, wherein the receiving member (13; 23; 33; 43; 63; 73) is a rotated, deep-drawn or extruded member.

A rail assembly (1; 4; 6; 7) according to any one of the preceding claims, wherein the receiving member (13; 23; 33; 43; 63; 73) is made of stainless steel.

The rail assembly (6; 7) of any one of the preceding claims, wherein the fuel heater (62; 72) further includes a terminal bolt (622; 722) connected to the glow tube (621; 721) and a gasket (64; 74) the connection bolt (622; 722) protrudes from the glow tube (621; 721) and the seal (64; 74) is arranged between terminal bolts (622; 722) and receiving component (63; 73) and seals them to one another.

The rail assembly (6; 7) of claim 9, wherein the fuel heater (62; 72) further comprises an insulating washer (65; 75) and a round plug (623) or round nut (723), the insulating washer (65; 75). between seal (64; 74) and round plug (623) or round nut (723) is arranged, wherein the insulating disc (65; 75) is preferably made of an electrically non-conductive material, more preferably made of plastic.

Internal combustion engine with a rail assembly (1; 4; 6; 7) according to one of the preceding claims, wherein the internal combustion engine is designed for operation with alcohol, preferably methanol or ethanol, and gasoline, or an alcohol mixture and a mixture of alcohol and gasoline.