INJECTOR MOUNTING STRUCTURE

Abstract

Injector mounting structure, including: a head opening (4) and a cover opening (5), each provided, which penetrate a cylinder head (2) and a head cover (3) which are connected to each other; an injector (1) which is inserted into the head opening (4) and cover opening (5) with a gap in a radial direction; a first sealing element (6) which is detachably attached to the head cover (3) around the cover opening (5) and comes into contact with the injector (1) to seal a gap between the cover opening (5) and the injector (1); and a second sealing element (7) which is attached to be arranged between the cylinder head (2) and the head cover (3) around the head opening (4) and comes into contact with the injector (1) to seal a gap between the head opening (4) and the injector (1).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an injector mounting structure. STATE OF THE ART

[0002] Generally, in a direct-injection internal combustion engine, a head port and a cover port are provided, respectively, penetrating through a cylinder head and a head cover that are connected to each other. An injector is inserted into the head port and cover port with a gap in a radial direction. The gap between the cover port and the injector is sealed by a sealing member. CITATION LISTPATENT LITERATURE

[0003] Patent literature 1: JP 2009 - 236 219 A

[0004] DE 20 2008 007 478 U1 describes a fuel injector for injecting fuel into a combustion chamber of an internal combustion engine. The injector mounting structure includes a head opening and a cover opening, each provided and penetrating through a cylinder head and a head cover that are connected to each other; an injector inserted into the head opening and cover opening with a gap in a radial direction; and a first sealing member detachably attached to the head cover around the cover opening and contacting the injector to seal a gap between the cover opening and the injector.

[0005] DE 12 24 092 A describes an injection-type internal combustion engine with a fuel injection nozzle arranged in the cylinder head in the region of the cylinder's longitudinal center axis and a cover covering the cylinder head. A sealing element is described that is arranged between the cylinder head and the head cover around the head opening. DE 10 2013 017 146 A1 describes an arrangement of an injector on a cylinder head of an internal combustion engine. A sealing element is described that is arranged on the cylinder head around the head opening and that comes into contact with the injector to seal a gap between the head opening and the injector. SUMMARY OF THE INVENTION TECHNICAL PROBLEM

[0006] The sealing element described above may be detachably attached to the head cover. In this case, for example, when the injector is inserted and removed for position adjustment or the like during assembly, the sealing element may be displaced and the seal may become loose, creating a risk of water penetrating the cover opening and the head opening from the outside. If water penetrates the head opening, the water may remain at the bottom of the head opening for a relatively long period of time and cause rust to the cylinder head and injector.

[0007] Therefore, the present disclosure is developed in view of such circumstances, and one of its objects is to provide an injector mounting structure that reduces the intrusion of water into a head opening. SOLUTION TO THE PROBLEM

[0008] According to one aspect of the present disclosure, an injector mounting structure is provided, including: a head opening and a cover opening each provided and penetrating through a cylinder head and a head cover connected to each other; an injector inserted into the head opening and cover opening with a gap in a radial direction; a first sealing member detachably secured to the head cover around the cover opening and contacting the injector to seal a gap between the cover opening and the injector; and a second sealing member mounted to be disposed between the cylinder head and the head cover around the head opening and coming into contact with the injector to seal a gap between the head opening and the injector.

[0009] Preferably, the second sealing element seals a gap between the cylinder head and the head cover. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0010] According to the present disclosure, it is possible to reduce the intrusion of water into a head opening. BRIEF DESCRIPTION OF THE DRAWINGS [ Fig. 1] Fig. 1 is a vertical cross-sectional view illustrating an injector mounting structure. [ Fig. 2] Fig. 2 is an enlarged view of a main part of Fig. 1. DESCRIPTION OF THE EMBODIMENT

[0011] Hereinafter, an embodiment of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the following embodiment.

[0012] Fig. 1 is a vertical cross-sectional view illustrating an injector mounting structure according to the present embodiment. Such a mounting structure is a structure for mounting an injector 1 as a fuel injection valve on a direct injection internal combustion engine (engine). The engine of the present embodiment is a diesel engine for a vehicle, but the type and use thereof are not particularly limited. For example, the engine may be a gasoline engine.

[0013] The engine is multi-cylinder, but the figure shows only one cylinder. For simplicity, the dimensions of each part have been distorted to emphasize the characteristics of each part.

[0014] The injector mounting structure includes a head hole 4 and a cover hole 5 each provided and penetrating through a cylinder head 2 and a head cover 3 connected to each other, the injector 1 inserted into the head hole 4 and the cover hole 5 with a gap in a radial direction, a first sealing member 6 detachably attached to the head cover 3 around the cover hole 5 and coming into contact with the injector 1 to seal a gap between the cover hole 5 and the injector 1, and a second sealing member 7 attached so as to be disposed between the cylinder head 2 and the head cover 3 around the head hole 4 and coming into contact with the injector 1 to seal a gap between the head hole 4 and the injector 1.

[0015] In the present embodiment, the cylinder head 2 is divided into upper and lower parts and consists of a cylinder head main body 2A on a lower side and a cam carrier 2B on an upper side. These are superimposed and assembled by bolts, which is not illustrated. A valve, a valve spring, and the like (not illustrated) are mainly mounted on the cylinder head main body 2A, and a camshaft (not illustrated) is mainly mounted on the cam carrier 2B. The cylinder head 2 may not have a divided structure.

[0016] The head port 4 consists of a main body port 4A provided in the cylinder head main body 2A and a support port 4B provided in the cam support 2B. These ports 4A and 4B are coaxially positioned. These ports 4A and 4B have slightly larger diameters than the injector 1 and have the same diameter, but may have different diameters from each other. A reduced diameter portion 9 is provided at a lower end portion of the main body port 4A, and a shoulder portion 8 formed from a plane perpendicular to an opening axis C is formed in the main body port 4A. A shoulder portion 10 of the injector 1 is pressed against the shoulder portion 8 to seal the space between the injector 1 and the main body port 4A.A packing seal may be provided between the shoulder portion 8 of the main body opening 4A and the shoulder portion 10 of the injector 1. The opening axis C represents a center axis of the head opening 4 and, in the present embodiment, a center axis of the support opening 4B.

[0017] A reduced-diameter nozzle portion 1A of the injector 1 is inserted into the reduced-diameter portion 9. Fuel is injected into a combustion chamber 12 from an injection port 11 at a tip of the nozzle portion 1A.

[0018] The head cover 3 is mounted on the cam support 2B and covers the cam support 2B. The head cover 3 of the present embodiment is made of resin, but may also be made of metal. The head cover 3 is mounted on the cam support 2B by a plurality of screws 13 (only one is illustrated). A collar 14 having a cylindrical shape is fitted around the screw 13 to prevent compression deformation of the head cover 3 due to tightening of the screw 13. The collar 14 is arranged and inserted into a collar opening 15 of the head cover 3, and a gap between the collar 14 and the collar opening 15 is sealed by a paint seal member 16. The screw 13 is fastened into an internally threaded hole 21 provided in the cam support 2B.

[0019] The cover opening 5 is positioned coaxially with the support opening 4B. The cover opening 5 has a slightly larger diameter than the injector 1 and has the same diameter as the support opening 4B, but may have a different diameter than the support opening 4B.

[0020] Further, an injector holder 17 is provided, which pushes the injector 1 downward to press the shoulder portion 10 of the injector 1 against the shoulder portion 8 of the main body opening 4A. As is well known, the injector holder 17 is provided with a forked finger portion 18 at the tip thereof. The injector holder 17 is pushed downward by a screw 19 to rotate around a base end portion as a fulcrum, and the finger portion 18 pushes down an engagement surface 20 of the injector 1.

[0021] The bolt 19 is sequentially inserted from above into an insertion hole 22 provided in the head cover 3 and an insertion hole 23 provided in the cam carrier 2B, and then tightened into an internally threaded hole 24 provided in the cylinder head main body 2A. A head portion (not illustrated) located at an upper end of the bolt 19 presses the injector holder 17 downward.

[0022] As in Fig.As illustrated in Figure 2, the first sealing member 6 is an annular member made of an elastic material such as rubber. The first sealing member 6 integrally includes an annular, plate-shaped disc portion 25 perpendicular to the opening axis C and a cylindrical flange portion 26 projecting downward in a direction of the opening axis C from an outer peripheral end edge portion of the disc portion 25. The first sealing member 6 is formed in an L-shape in a cross-sectional view.

[0023] Accordingly, a first fastening groove 27 for fastening the first sealing member 6 around the cover opening 5 is provided on an upper surface portion of the head cover 3. The first fastening groove 27 is also formed in a ring shape and an L-shape in a cross-sectional view.

[0024] The first sealing element 6 is detachably secured to the first fastening groove 27 in close contact with an inner surface of the first fastening groove 27 by a spring force of the first sealing element 6. Specifically, outer peripheral surfaces of the disc portion 25 and the flange portion 26 resiliently come into close contact with an outer peripheral surface 28 of the first fastening groove 27, and an inner peripheral surface of the flange portion 26 resiliently comes into close contact with an inner peripheral surface 29 of the first fastening groove 27. The disc portion 25 is then located on a bottom surface 30 of the first fastening groove 27.

[0025] An inner peripheral end edge portion 31 of the disc portion 25 resiliently comes into close contact with an outer peripheral surface 32 of the injector 1. Consequently, a gap 33 between the cover opening 5 and the outer peripheral surface 32 of the injector 1 is sealed.

[0026] "A comes into resilient close contact with B" means that A comes into close contact with B due to a reaction force from A, compressed and deformed by B.

[0027] The first sealing member 6 mainly acts as a dust seal to prevent external dust from entering the gap 33.

[0028] Next, the second sealing member 7 will be described. The second sealing member 7 is an annular member made of an elastic material such as rubber. The second sealing member 7 integrally includes an annular, plate-shaped disc portion 41 perpendicular to the opening axis C and a cylindrical flange portion 42 projecting downward in a direction of the opening axis C from a central portion of the disc portion 41 in the radial direction. The second sealing member 7 is formed in a T-shape in a cross-sectional view.

[0029] The disc portion 41 is fixed to be disposed between an upper surface of the cam carrier 2B and a lower surface of the head cover 3. Further, an annular recess portion 43 is provided on an upper surface portion of the cam carrier 2B for arranging and inserting the flange portion 42 at a position radially outside the carrier opening 4B with a predetermined pitch.

[0030] When the disc portion 41 is clamped in a state where the flange portion 42 is inserted into the recessed portion 43, as indicated by the arrow, an upper surface 41A of the disc portion 41 resiliently comes into close contact with the lower surface of the head cover 3, and a bottom surface 42A of the flange portion 42 resiliently comes into close contact with a bottom surface of the recessed portion 43. Consequently, a gap 44 between the cam carrier 2B and the head cover 3 is sealed by the second sealing member 7. On the other hand, the gap 44 is also sealed by a third sealing member 45.

[0031] An inner peripheral end edge portion 46 of the disc portion 41 resiliently comes into close contact with an outer peripheral surface 32 of the injector 1. Consequently, a gap 47 between the support opening 4B and the outer peripheral surface 32 of the injector 1 is sealed. That is, the gap 47 is sealed or insulated from the gap 44 between the cam support 2B and the head cover 3, and simultaneously sealed or insulated from the gap 33 between the cover opening 5 and the injector 1.

[0032] The second sealing member 7 primarily functions as an oil seal to prevent the oil in the cylinder head 2, which is present in the gap 44, from penetrating into the gap 47. At the same time, the present embodiment is characterized in that the second sealing member 7 has a function of preventing water, which penetrates into the gap 33, from penetrating into the gap 47. The third sealing member 45 functions as an oil seal similar to the second sealing member 7.

[0033] In the present disclosure, the first sealing member 6 is not fixed to the head cover 3, but is detachably attached. In this case, for example, when the injector 1 is inserted and removed for position adjustment or the like during assembly, or when the engine vibrates, the first sealing member 6 may be displaced and the seal may become loose, thus creating a risk that water may enter the cover opening 5 or the gap 33 from the outside. The displacement of the first sealing member 6 involves the fact that part or all of the first sealing member 6 deviates from the first fastening groove 27.

[0034] In a comparative example prior to the concept of the present disclosure, the second sealing member 7 does not come into contact with the injector 1. Therefore, water penetrating the cover hole 5 or the gap 33 may further penetrate from a gap between the second sealing member 7 and the injector 1 into the head hole 4 or the gap 47 below the gap. When water penetrates, the water may remain on the bottom portion of the head hole 4 (particularly, the main body hole 4A) for a relatively long period of time, causing the cylinder head 2 (particularly, the cylinder head main body 2A) of the injector 1 to rust.

[0035] In contrast, in the present embodiment, the second sealing member 7 comes into contact with the injector 1 and seals the gap (specifically, the gap 47 between the support hole 4B and the injector 1) between the head hole 4 and the injector 1. Therefore, even if water enters the cover hole 5, the water can be stopped, thus reducing the intrusion of water into the head hole 4. Then, the water can be prevented from remaining at the bottom portion of the head hole 4 and, for example, rusting the cylinder head main body 2A and the injector 1.

[0036] Since the second sealing member 7 is fixed to be arranged between the cylinder head 2 (particularly, the cam carrier 2B) and the head cover 3, the second sealing member 7 is not displaced due to the insertion and removal of the injector 1 or the vibration of the engine, and thus the sealing can be stably maintained for a long period of time.

[0037] Furthermore, since it is only necessary to reduce the inner diameter of the existing second sealing member 7 in the comparative example and to bring the existing second sealing member 7 into contact with the injector 1, the desired effect can be obtained by slightly improving the configuration of the existing second sealing member 7.

[0038] Since the second sealing member 7 is fixed in a clamped manner, even if the inner diameter of the second sealing member 7 is set small and the inner peripheral end edge portion 46 is brought into strong contact with the injector 1, it may be difficult to displace the second sealing member 7 when, for example, the injector 1 is inserted and removed. Therefore, the stability of the seal can be improved while enhancing the sealing property.

[0039] Although the embodiment of the present disclosure is described in detail above, the present disclosure may also include the following other embodiments.

[0040] (1) For example, the cross-sectional shape of the second sealing member 7 may be changed and may be L-shaped or the like.

[0041] (2) Similarly, the cross-sectional shape of the first sealing member 6 can be changed.

[0042] The embodiment of the present disclosure is not limited to the above-described embodiment, and all modification examples, application examples, and equivalents included in the ideas of the present disclosure, which are defined by the scope of the claims, are included in the present disclosure. Therefore, the present disclosure should not be construed in a limiting manner and can be applied to any other technology that falls within the scope of the ideas of the present disclosure.

[0043] This application is based on a Japanese patent application filed on September 20, 2019 (Japanese Patent Application No. 2019-171579), the contents of which are incorporated herein by reference. INDUSTRIAL APPLICABILITY

[0044] According to the present disclosure, it is useful in that it is possible to provide an injector mounting structure capable of reducing the intrusion of water into a head opening. REFERENCE SYMBOL LIST 1 injector 2 cylinder head 3 Head cover 4 Head opening 5 Cover opening 6 first sealing element 7 second sealing element

Claims

[1] Injector mounting structure comprising: a head opening (4) and a cover opening (5) respectively provided and penetrating through a cylinder head (2) and a head cover (3) connected to each other; an injector (1) inserted into the head opening (4) and cover opening (5) with a gap in a radial direction; a first sealing member (6) detachably secured to the head cover (3) around the cover opening (5) and coming into contact with the injector (1) to seal a gap between the cover opening (5) and the injector (1); and a second sealing member (7) mounted to be disposed between the cylinder head (2) and the head cover (3) around the head opening (4) and coming into contact with the injector (1) to seal a gap between the head opening (4) and the injector (1). [2] The injector mounting structure according to claim 1, wherein the second sealing member (7) seals a gap between the cylinder head (2) and the head cover (3).

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