JP5558293B2 - Support device for fuel injection valve - Google Patents

Description

  In the present invention, a fuel distribution pipe is fitted on the outer periphery of a fuel inlet cylinder on the rear end side of a fuel injection valve in which a nozzle cylinder portion on the front end side is inserted into an engine mounting hole, and fuel injection is performed in cooperation with the fuel distribution pipe. The present invention relates to an improvement in a fuel injection valve support device in which an alignment mechanism for holding a valve in an axial direction is interposed between an engine and a fuel injection valve.

  Such a support device for a fuel injection valve is already known as disclosed in Patent Document 1.

JP 2010-138810 A

  According to such a fuel injection valve support device, even if the axis of the fuel injection valve is inclined due to processing errors and assembly errors of the engine mounting holes and fuel distribution pipes, the alignment mechanism can adjust the inclination. By allowing it, the support of the fuel injection valve by the mounting hole and the fuel distribution pipe can be stabilized.

  However, in such a conventional fuel injection valve support device, a support hole is provided in the engine at the rear end of the mounting hole via a rearward stepped portion, and a centering mechanism is annularly supported on the rearward stepped portion. The washer, a rearward annular convex curved surface formed on the inner peripheral surface of the washer, and a forward conical surface formed on the fuel injection valve so as to be in contact with the annular convex curved surface. In order to form a backward annular convex curved surface on the washer, a special curved surface processing must be performed, which is one factor hindering cost reduction.

  The present invention has been made in view of such circumstances, and provides a support device for a fuel injection valve capable of obtaining an alignment mechanism easily and inexpensively without performing special processing. For the purpose.

  In order to achieve the above object, the present invention provides a fuel distribution pipe fitted on the outer periphery of a fuel inlet cylinder at the rear end of a fuel injection valve in which a nozzle cylinder portion at the front end is fitted in a mounting hole of an engine. In a fuel injection valve support device comprising a centering mechanism for holding the fuel injection valve in an axial direction in cooperation with the engine and the fuel injection valve, a rearwardly stepped portion is connected to the rear end of the mounting hole. A ring-shaped ring holder accommodated in the support hole so as to be supported by the rearward stepped portion surrounding the fuel injection valve, and an inner ring of the ring holder. The first structure comprises a circular ring-shaped support ring held in an annular recess opened rearward of the peripheral surface, and a forward conical surface formed on the fuel injection valve so as to be in contact with the support ring. Features.

  According to the present invention, in addition to the first feature, the support ring is provided with one cut end and a tension that can be expanded from the inner diameter of the annular recess, and the support ring is elastically attached to the annular recess. The second feature is that it is mounted on the machine.

  Furthermore, in addition to the first or second feature, the third feature of the present invention is that the support ring is formed by bending a steel wire having a circular cross section into an annular shape.

  According to the first feature of the present invention, when the center axis of the fuel injection valve is inclined due to processing errors and assembly errors of the mounting holes and the fuel distribution pipes, the ring holder in the aligning mechanism causes the rearward step of the engine. The center axis of the fuel injection valve is inclined by sliding the outer circumferential surface of the circular support ring so that the forward conical surface of the fuel injection valve swings around its center. Permissible. This can prevent an excessive bending load from acting on the fuel injection valve. In addition, the ring holder, support ring, and conical surface that make up the alignment mechanism can be easily obtained without any special processing, thereby reducing the cost of the alignment mechanism and, consequently, the fuel injection valve support device. Can contribute.

  According to the second feature of the present invention, the support ring having one cut is elastically attached to the annular recess of the ring holder by its own tension. The support ring attached to the lens does not fall off, making the alignment mechanism easy to assemble. Moreover, even if it receives engine vibration, generation | occurrence | production of the vibration noise from between a ring holder and a support ring can be prevented.

  According to the third feature of the present invention, the support ring can be easily obtained from an inexpensive steel wire, which can contribute to further cost reduction of the aligning mechanism and thus the fuel injection valve support device.

The longitudinal section side view which shows the support apparatus of the fuel injection valve which concerns on this invention. The disassembled perspective view of the ring holder and support ring of the alignment mechanism in the said support apparatus.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  In FIG. 1, the cylinder head 1 of the engine E is provided with a mounting hole 1b that opens into the combustion chamber 1a, and the front end portion of the electromagnetic fuel injection valve I is fitted into the mounting hole 1b. The fuel injection valve I can inject fuel toward the combustion chamber 1a. In the fuel injection valve I, “front” means the nozzle cylinder portion 3a side, and “rear” means the fuel inlet cylinder 7 side.

  The valve housing 2 of the fuel injection valve I includes a valve seat member 3, a magnetic cylinder 4 coaxially coupled to the rear end of the valve seat member 3, and a coaxial coupling to the rear end of the magnetic cylinder 4. The nonmagnetic cylindrical body 5 is made up of. A fixed core 6 is coaxially coupled to the rear end of the nonmagnetic cylindrical body 5, and a fuel inlet cylinder 7 is coaxially connected to the rear end of the fixed core 6. The fixed core 6 has a hollow portion 6 a communicating with the inside of the fuel inlet cylinder 7.

  The valve seat member 3 includes a nozzle cylinder portion 3a having a front end wall and a flange portion 3b formed at the rear end of the nozzle cylinder portion 3a. The front end wall of the nozzle cylinder portion 3a has a conical shape. A valve seat 8 and a fuel injection hole 9 connected to the front end of the valve seat 8 are provided.

  A seal groove 10 is formed on the outer periphery of the tip of the nozzle tube portion 3a, and the nozzle tube portion 3a is attached to the seal member 11 so as to be in close contact with the inner peripheral surface of the mounting hole 1b. It is fitted in the hole 1b.

  The magnetic cylinder 4 has a large-diameter hollow portion 4a that opens to the front end surface thereof, and a small-diameter hollow portion 4b that continues to the rear end of the large-diameter hollow portion 4a via a forward stepped portion 4c. A stopper plate 15 that contacts the forward stepped portion 4 c is fitted into the diameter hollow portion 4 a, and the flange portion 3 b is fitted over the stopper plate 15, and the flange portion 3 b is attached to the magnetic cylindrical body 4. Closely welded.

  The valve assembly V is accommodated in the valve housing 2 extending from the valve seat member 3 to the nonmagnetic cylindrical body 5. The valve assembly V is a movable core that is slidably fitted to the inner peripheral surfaces of the magnetic cylinder 4 and the nonmagnetic cylinder 5 so as to face the front end suction surface of the fixed core 6 with a certain gap. 16 and a needle valve body 17 which is coupled to the front end portion of the movable core 16 and opens and closes the valve hole 9 in cooperation with the valve seat 8. The needle valve body 17 includes a nozzle cylinder portion 3a. A pair of upper and lower journal portions 18a, 18b that are slidably fitted to the inner peripheral surface are formed, and a flat surface that allows fuel to flow in the nozzle cylinder portion 3a is formed on the outer periphery of the journal portions 18a, 18b. It is formed. Further, the needle valve body 17 is formed with a stopper flange 19 that abuts against the stopper plate 15 and defines the valve opening limit. A cutout 20 is provided on the outer periphery of the movable core 16 to communicate the hollow portion 6a of the fixed core 6 with the nozzle cylinder portion 3a.

  A pipe-shaped retainer 21 is fitted into the hollow portion 6 a of the fixed core 6, and a valve spring 22 that biases the movable core 16 toward the valve closing side of the needle valve body 17 between the retainer 21 and the movable core 16. Is reduced.

  A coil assembly 25 is fitted on the outer peripheral surface of the portion from the rear end portion of the magnetic cylindrical body 4 to the fixed core 6. The coil assembly 25 includes a bobbin 26 fitted to the outer peripheral surface and a coil 27 wound around the bobbin 26, and a front end of a coil housing 28 surrounding the coil assembly 25 is a magnetic cylindrical body 4. An annular yoke 29 connected to the rear end surface of the coil housing 28 by welding is connected to the outer peripheral surface of the fixed core 6 by welding or the like.

  A resin coating layer 30 is molded on the outer peripheral surface from the rear end portion of the magnetic cylindrical body 4 to the intermediate portion of the fuel inlet cylinder 7. A connector housing portion 51 is formed in a notch shape on the outer periphery of the rear portion of the resin coating layer 30, and a connector 52 connected to the coil 27 is disposed in the connector housing portion 51. A cover 53 made of synthetic resin is closed to the resin coating layer 30. The connector 52 is connected to a power supply external conductor 54.

  A seal groove 35 is formed on the outer periphery of the rear end portion of the fuel inlet cylinder 7, and an O-ring 36 and a backup ring 37 that receives the back surface of the seal groove 35 are attached to the seal groove 35. A joint cylinder portion 38a of a fuel distribution pipe 38 fixed to an appropriate position of the engine E is fitted on the outer periphery of the rear end portion of the fuel inlet cylinder 7, and the O-ring 36 is pressed against the inner peripheral surface of the joint cylinder portion 38a. To do.

  The cylinder head 1 is provided with a stepped support hole 40 having a diameter larger than that connected to the rear end of the mounting hole 1b. The support hole 40 includes an intermediate portion of the fuel injection valve I including the magnetic cylindrical body 4 and , And an aligning mechanism 41 that supports the magnetic cylinder 4 in an aligning manner.

  The stepped support hole 40 includes a small-diameter hole 40a on the mounting hole 1b side and a large-diameter hole 40b coaxially connected to the rear end of the small-diameter hole 40a via a rearwardly-facing step portion 40b. Includes an annular ring holder 42 accommodated in the large-diameter hole 40b so as to be supported by the rearwardly stepped portion 40b while surrounding the magnetic cylindrical body 4, and a circular cross-section and annular shape held by the ring holder 42. The support ring 43 and a support flange 44 having a forward conical surface 44 a that projects integrally with the outer peripheral surface of the magnetic cylindrical body 4 and contacts the support ring 43.

  As shown in FIG. 2, an annular recess 42a opened rearward is provided on the inner peripheral surface of the ring holder 42, and a support ring 43 is accommodated and held in the annular recess 42a. The ring holder 42 having such an annular recess 42a is formed by pressing a steel plate.

  Further, as shown in FIG. 2, the support ring 43 is formed by bending a steel wire having a circular cross section into an annular shape, and a gap 43a between the opposite ends of the steel wire serves as a cut 43a of the support ring 43. The support ring 43 is provided with a tension that allows the outer diameter to be larger than the inner diameter of the annular recess 42a.

  The ring holder 42 support ring 43 is fitted around the magnetic cylinder 4 from the nozzle cylinder portion 3a side of the fuel injection valve I before the fuel injection valve I is mounted on the cylinder head 1. A set ring 45 that prevents the holder 42 from falling off the magnetic cylindrical body 4 is mounted in an annular locking groove 46 on the outer periphery of the front end portion of the magnetic cylindrical body 4.

  The large-diameter hole 40b of the support hole 40 is formed to have a larger diameter than the ring holder 42 so that the ring holder 42 can slide on the rearward stepped portion 40b when the alignment mechanism 41 is operated. The small-diameter hole 40a has a larger diameter than the set ring 45 so as to avoid interference with the set ring 45 when the aligning mechanism 41 is operated.

  Next, the operation of this embodiment will be described.

  When the coil 27 is demagnetized, the valve assembly V is pressed forward by the urging force of the valve spring 22, and the needle valve body 17 is seated on the valve seat 8. When the coil 27 is energized by energization, the magnetic flux generated by the coil 27 sequentially travels through the fixed core 6, the coil housing 28, the magnetic cylindrical body 4, and the movable core 16, and the movable core 16 resists the set load of the valve spring 22 by the magnetic force. Since the needle valve body 17 is sucked into the fixed core 6 and separated from the valve seat 8, the fuel pumped from the fuel pump (not shown) to the fuel inlet cylinder 7 through the fuel distribution pipe 38 is contained in the pipe-like retainer 21 and The fuel is injected directly from the fuel injection hole 9 into the combustion chamber 1a of the engine E through the hollow portion 6a of the fixed core 6, the notch 20 of the movable core 16, the nozzle cylinder portion 3a and the valve seat 8 in order.

  During this time, the pressure of the high-pressure fuel introduced into the joint cylinder portion 38a of the fuel distribution pipe 38 acts on the rear end surface of the fuel inlet cylinder 7 of the fuel injection valve I as a forward pressing force. It is received by the rearward stepped portion 40b of the cylinder head 1 through the center mechanism 41, that is, through the support flange 44, the support ring 43 and the ring holder 42.

  By the way, the fuel injection valve I has the nozzle cylinder portion 3a fitted in the mounting hole 1b of the cylinder head 1 via the seal member 11, and the alignment mechanism 41 supported by the rearward stepped portion 40b of the cylinder head 1. And the joint cylinder portion 38a of the fuel distribution pipe 38 fitted to the outer periphery of the fuel inlet cylinder 7 is held in the axial direction. At this time, if the center axis Y of the fuel injection valve I is inclined due to processing errors and assembly errors of the mounting hole 1b and the fuel distribution pipe 38, the ring holder 42 moves over the rearwardly stepped portion 40b in the aligning mechanism 41. While sliding in the radial direction, the forward conical surface 44a of the fuel injection valve I slides on the outer peripheral surface of the support ring 43 having a circular cross section so as to swing around the center thereof. Tilt is allowed. As a result, an excessive bending load can be prevented from acting on the fuel injection valve I, and the seal member 11 between the mounting hole 1b of the cylinder head 1 and the nozzle tube portion 3a, the fuel inlet tube 7 and the joint tube portion. It is possible to avoid that an uneven load acts on the O-ring 36 between 38a, and to keep their sealing functions in a normal state.

  By the way, the ring holder 42, the support ring 43, and the conical surface 44a constituting the alignment mechanism 41 can be easily obtained without any special processing.

  In particular, the ring holder 42 having the annular recess 42a can be easily obtained by pressing a steel plate, and the support ring 43 having a circular cross section can also be easily obtained by bending an inexpensive steel wire into an annular shape. This contributes to the cost reduction of the aligning mechanism 41 and thus the support device for the fuel injection valve I.

  Further, the support ring 43 having one cut-out 43a is elastically attached to the annular recess 42a of the ring holder 42 by its own tension, so that it is temporarily attached to the ring holder 42 during the assembly of the alignment mechanism 41. The support ring 43 does not drop off, and the assembly of the alignment mechanism 41 is improved, and generation of vibration noise from between the ring holder 42 and the support ring 43 can be prevented even when engine vibration is received.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention. For example, the present invention can be applied to a support device for a fuel injection valve that injects fuel into an intake system of an engine.

E ··· Engine I ··· Fuel injection valve Y ··· Fuel injection valve central axis 1a · Mounting hole 3a · · · Nozzle cylinder 7 · · · ··· Fuel inlet tube 40 ··· Support hole 40c ··· Backward stepped portion 41 ··· Centering mechanism 42 ··· Ring holder 42a ··· Ring recess 43 ··· .... Support ring 43a ... Cut 44 ... Support flange 44a ... Conical surface

Claims (3)

A fuel distribution pipe (38) is fitted to the outer periphery of the fuel inlet cylinder (7) at the rear end of the fuel injection valve (I) in which the nozzle cylinder portion (3a) at the front end is fitted into the mounting hole (1b) of the engine (E). A centering mechanism (41) for holding the fuel injection valve (I) in the axial direction in cooperation with the fuel distribution pipe (38) is interposed between the engine (E) and the fuel injection valve (I). In the fuel injection valve support device,
The engine (E) is provided with a support hole (40) connected to the rear end of the mounting hole (1b) and having a backward stepped portion (40b), and the alignment mechanism (41) surrounds the fuel injection valve (I). An annular ring holder (42) received in the support hole (40) so as to be supported by the rearward stepped portion (40b), and an annularly opened rearward direction of the inner peripheral surface of the ring holder (42) A circular ring-shaped support ring (43) held in the recess (42a) and a forward conical surface (44a) formed on the fuel injection valve (I) so as to be in contact with the support ring (43). A fuel injection valve support device characterized by comprising. The fuel injection valve support device according to claim 1,
The support ring (43) is provided with a single cut (43a) and is provided with a tension that can be larger than the inner diameter of the annular recess (42a). The support ring (43) is provided with the annular recess (42a). A fuel injection valve support device characterized by being elastically attached to the fuel injection valve. The fuel injection valve support device according to claim 1 or 2,
A support device for a fuel injection valve, wherein the support ring (43) is formed by bending a steel wire having a circular cross section into an annular shape.

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