(19)
(11)EP 3 284 945 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
29.04.2020 Bulletin 2020/18

(21)Application number: 16779723.2

(22)Date of filing:  01.02.2016
(51)International Patent Classification (IPC): 
F02M 55/02(2006.01)
F02M 69/46(2006.01)
F02M 37/00(2006.01)
(86)International application number:
PCT/JP2016/000493
(87)International publication number:
WO 2016/166923 (20.10.2016 Gazette  2016/42)

(54)

GASOLINE DIRECT INJECTION RAIL

BENZINDIREKTEINSPRITZUNGSVERTEILERROHR

RAIL D'INJECTION DIRECTE D'ESSENCE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 15.04.2015 JP 2015083009

(43)Date of publication of application:
21.02.2018 Bulletin 2018/08

(73)Proprietor: Usui Co., Ltd.
Sunto-gun Shizuoka 411-8610 (JP)

(72)Inventors:
  • NISHIZAWA, Hiroyuki
    Shizuoka 411-8610 (JP)
  • SUZUKI, Shuji
    Shizuoka 411-8610 (JP)

(74)Representative: Isarpatent 
Patent- und Rechtsanwälte Behnisch Barth Charles Hassa Peckmann & Partner mbB Friedrichstrasse 31
80801 München
80801 München (DE)


(56)References cited: : 
JP-A- H08 114 160
JP-A- 2004 036 441
JP-A- 2007 285 213
JP-A- 2014 047 671
JP-A- 2003 049 741
JP-A- 2007 247 641
JP-A- 2013 213 470
US-A1- 2013 001 891
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    Technical Field



    [0001] The present invention relates to a gasoline direct injection rail.

    Background Art



    [0002] Direct injection gasoline engines have started to come back into widespread use since 2005 in Europe, and many gasoline direct injection rails in recent years are made of stainless materials that have excellent corrosion resistance. However, gasoline direct injection rails made of stainless materials may result in stress corrosion cracking when placed in a chlorine atmosphere or when a corrosive medium such as chlorine is contained in fuel.

    [0003] On the other hand, steel materials are available in a wide variety of strengths and are inexpensive, and therefore steel materials attract attention as materials having better mechanical properties and greater cost advantages than stainless materials for higher-pressure systems of the future. Thus, recently, there are increasing demands for gasoline direct injection rails made of steel materials. JP 2012-97690A and JP 2013 213470 A are known examples.

    Summary of Invention


    Technical Problem



    [0004] However, in the case of using a steel gasoline direct injection rail, the surface needs to be plated to prevent rust and corrosion. An inlet part provided in a gasoline direct injection rail is often given an orifice as shown in the aforementioned examples to reduce pressure fluctuations resulting from the injections of a fuel pump and an injector. In such a case, because the inner diameter of a commonly used orifice is as small as about 1 to 2 mm, a plating solution when performing plating treatment is unlikely to enter inside, and is also unlikely to come out, through the orifice. Therefore, it is difficult to reliably perform plating treatment on the inner circumferential surface of the orifice and the inner circumferential surface of the rail body.

    [0005] Accordingly, an object of the present invention is to solve the above-described problem and to obtain a gasoline direct injection rail that enables plating treatment to be easily and reliably performed on the inside of the rail body and the inlet part, that also includes an orifice, and that has excellent mechanical properties.

    Solution to Problem



    [0006] The present invention has solved the above-described problem, and is a gasoline direct injection rail as defined in claim 1. Screw-fixing the orifice member to the inlet part makes it possible to firmly fix the orifice member to the inlet part. Unlike in the case of merely fixing the orifice member to the inlet part by insertion, it is not necessary to precisely adjust the dimensions of the outer diameter of the orifice member and the inner diameter of the inlet part, it is easy to position the orifice member relative to the inlet part, and it is thus easy to securely dispose the orifice member in the inlet part. Furthermore, in comparison to the case where the orifice member is fixed to the inlet part with an adhesive, there is no concern of dirt derived from the adhesive and, moreover, the problem of contamination between the adhesive and fuel does not arise.

    Advantageous Effects of Invention



    [0007] As described above, in the present invention, the stainless orifice member that is formed separately from the inlet part is screw-fixed to the communication passage of the inlet part provided in the steel rail body. Therefore, performing plating treatment on the rail body provided with the inlet part before securely disposing the orifice member in the inlet part makes it possible to cause a plating solution to easily flow into and flow out of the inside of the inlet part and the rail body because the orifice is not present inside the inlet part and the rail body, and makes it possible to easily perform plating treatment. Since the orifice member is made of a stainless material, it is not necessary to perform plating treatment, and therefore the problem of conventional art concerning plating treatment on a small-diameter orifice does not arise. Since the rail body is made of steel, products can be obtained that are available in a wide variety of strengths and have better mechanical properties than stainless materials for high-pressure systems of the future.

    Brief Description of Drawings



    [0008] 

    [Figure 1] Figure 1 is a partially enlarged cross-sectional view of a known example before an orifice member is attached to an inlet part.

    [Figure 2] Figure 2 is a partially enlarged cross-sectional view of a known example after an orifice member is attached to an inlet part.

    [Figure 3] Figure 3 is a partially enlarged cross-sectional view of another known example before an orifice member is attached to an inlet part.

    [Figure 4] Figure 4 is a partially enlarged cross-sectional view of another known example after an orifice member is attached to an inlet part.

    [Figure 5] Figure 5 is a partially enlarged cross-sectional view of an embodiment before an orifice member is attached to an inlet part.

    [Figure 6] Figure 6 is a partially enlarged cross-sectional view of an embodiment after an orifice member is attached to an inlet part.



    [0009] A known example will now be described in reference to Figures 1 and 2 where (1) is an orifice member and is formed of a stainless material. By forming the orifice member (1) from a stainless material, it is not necessity to perform plating treatment for preventing rust and corrosion. The orifice member (1) is formed in a cylindrical shape and is provided with an orifice (2) in the length direction, and the outer circumferential surface thereof has an outer circumferential thread (3) as shown in Figure 1.

    [0010] On the other hand, in a rail body (4) of the gasoline direct injection rail, an inlet part (6) that is formed separately from the rail body (4) is securely disposed at a first end (5) thereof. The inlet part (6) is formed separately from the rail body (4) and is securely disposed at the first end (5) of the rail body (4) as described above, but the inlet part (6) may be formed integrally with the rail body (4) in another embodiment. The rail body (4) and the inlet part (6) are made of steel. A plurality of injector holders (not shown) that are in communication with the fuel passage of the rail body (4) are disposed so as to be connected to the rail body (4) at equal intervals in the length direction.

    [0011] A communication passage (7) is provided in the inlet part (6), and by attaching the inlet part (6) to the rail body (4) as shown in Figure 1, a state is reached where the communication passage (7) is in communication with the fuel passage (not shown) of the rail body (4). On the opening (8) side of the communication passage (7) of the inlet part (6), a tapered part (10) is formed that is continuous with the communication passage (7) and has a larger diameter on the opening (8) side and a smaller diameter on the side opposite the opening part (8). The communication passage (7) has an attachment hole (11) for attachment of the orifice member (1). The inner circumferential surface of the attachment hole (11) has an inner circumferential thread (12) that can be screw-fitted to the outer circumferential thread (3) of the orifice member (1).

    [0012] Since the rail body (4) and the inlet part (6) are made of steel, it is necessary to perform plating treatment. Accordingly, before screw-fixing the orifice member (1) to the inlet part (6), plating treatment is performed on the rail body (4) to which the inlet part (6) has been attached. At this time no orifice is provided in the inlet part (6) of the rail body (4), and it is thus possible to cause a plating solution to reliably flow into and flow out of the rail body (4) and the inlet part (6). Therefore, it is possible to easily and reliably perform plating treatment on the inner circumferences of the rail body (4) and the inlet part (6).

    [0013] According to the invention the orifice member (1) is screw-fixed to the attachment part of the inlet part (6) on which plating treatment has been performed as described above. Screw-fixing the orifice member (1) to the inlet part (6) in this way makes it possible to firmly fix the orifice member (1) to the inlet part (6). Unlike in the case of fixing the orifice member (1) to the inlet part (6) by insertion, it is not necessary to precisely adjust the dimensions of the outer diameter of the orifice member (1) and the inner diameter of the inlet part (6), it is easy to position the orifice member (1) relative to the inlet part (6), and it is thus easy to securely dispose the orifice member (1) in the inlet part (6). Furthermore, in comparison to the case where the orifice member (1) is fixed to the inlet part (6) with an adhesive, there is no concern of dirt derived from the adhesive and, moreover, the problem of contamination between the adhesive and fuel does not arise.

    [0014]  A screw stopper (13) that does not form the inner circumferential thread (12) is provided on the communication passage (7) side of the attachment hole (11) of the inlet part (6). Therefore, when screw-fixing the orifice member (1) to the inlet part (6), the screwing of the orifice member (1) is stopped by the screw stopper (13), thus making it possible to smoothly carry out the work without worrying about where to stop screwing at the time of attaching the orifice member (1). As shown in Figures 3 and 4, an inner circumferential step (14) is provided on the inner circumference on the communication passage (7) side of the attachment hole (11) to cause the inner circumferential step (14) to serve as the screw stopper (13), and as shown in Figures. 5 and 6, an outer circumferential projection (15) is provided on the outer circumference at one end of the orifice member (1) to cause the outer circumferential projection (15) to serve as the screw stopper (13).

    [0015] Since the orifice member (1) is formed of a stainless material as described above, it is not necessary to perform plating treatment on the orifice member (1). Therefore, the problem of conventional art that a plating solution is unlikely to flow in and flow out when performing plating treatment on the orifice (2) does not arise. Since the rail body (4) and the inlet part (6) are made of steel, products can be obtained that are available in a wide variety of strengths and have superior mechanical properties to stainless materials for high-pressure systems of the future.

    Reference Signs List



    [0016] 
    1
    Orifice member
    4
    Rail body
    5
    First end
    6
    Inlet part
    7
    Communication passage



    Claims

    1. A gasoline direct injection rail comprising:

    a steel rail body (4);

    an inlet part (6) provided integrally with or separately from a first end of the rail body (4) and comprising therein a communication passage (7) in communication with a fuel passage of the rail body (4); and

    a plurality of injector holders in communication with the fuel passage (7), wherein

    a stainless orifice member (1) formed separately from the rail body (4) is securely disposed in the communication passage (7) of the inlet part (6),

    wherein the communication passage (7) has an attachment hole (11) for attachment of the orifice member (1), and

    characterised in that:
    the orifice member (1) is screw-fixed to the communication passage of the inlet part, an inner circumferential step (14) is provided on the inner circumference on the communication passage (7) side of the attachment hole (11) to cause the inner circumferential step (14) to serve as a screw stopper (13), the screw stopper (13) does not form an inner circumferential thread (12), and at one end of the orifice member (1) an outer circumferential projection (15) is provided.


     


    Ansprüche

    1. Benzindirekteinspritzungsverteilerrohr, umfassend:

    einen Rohrkörper (4) aus Stahl;

    einen Einlassteil (6), der integral mit, oder separat von, einem ersten Ende des Rohrkörpers (4) ausgebildet und durch den hindurch ein Strömungsdurchgang (7) verläuft, der mit einem Kraftstoffdurchgang des Rohrkörpers (4) in Verbindung steht; und

    mehrere Injektorhalterungen, die mit dem Kraftstoffdurchgang (7) in Verbindung stehen,

    wobei ein rostfreies Öffnungselement (1), das von dem Rohrkörper (4) separat ausgebildet ist, fest in dem Strömungsdurchgang (7) des Einlassteils (6) angeordnet ist,

    wobei der Strömungsdurchgang (7) ein Befestigungsloch (11) zur Befestigung des Öffnungselements (1) aufweist, und

    dadurch gekennzeichnet, dass:
    das Öffnungselement (1) mit dem Strömungsdurchgang des Einlassteils verschraubt ist, eine Innenumfangsstufe (14) an dem Innenumfang auf der Seite des Strömungsdurchgangs (7) des Befestigungslochs (11) ausgebildet ist, um zu bewirken, dass die Innenumfangsstufe (14) als ein Schraub-Endanschlag (13) dient, der Schraub-Endanschlag (13) kein Innenumfangsgewinde (12) bildet, und an einem Ende des Öffnungselements (1) ein Außenumfangsvorsprung (15) vorhanden ist.


     


    Revendications

    1. Rail d'injection directe d'essence, comprenant :

    un corps de rail en acier (4) ;

    une partie d'entrée (6) formée d'une seule pièce avec une première extrémité du corps de rail (4) ou séparément de celle-ci et comprenant en son sein un passage de communication (7) en communication avec un passage de carburant du corps de rail (4) ; et

    une pluralité de porte-injecteurs en communication avec le passage de carburant (7), dans lequel :

    un élément à orifice inoxydable (1) formé séparément du corps de rail (4) est disposé de manière sûre dans le passage de communication (7) de la partie d'entrée (6), dans lequel le passage de communication (7) comporte un trou de fixation (11) permettant la fixation de l'élément à orifice (1), et

    caractérisé en ce que :

    l'élément à orifice (1) est vissé sur le passage de communication de la partie d'entrée,

    un épaulement circonférentiel intérieur (14) est ménagé sur la circonférence intérieure du côté passage de communication (7) du trou de fixation (11) pour faire que l'épaulement circonférentiel intérieur (14) serve de butée de vissage (13), la butée de vissage (13) ne forme pas de filetage circonférentiel intérieur (12), et à une extrémité de l'élément à orifice (1) se trouve une saillie circonférentielle extérieure (15).


     




    Drawing














    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description