JP2010209738A - Fuel injection device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection device of an internal combustion engine that allows an axial misalignment that occurs between a delivery pipe and respective fuel injection valves without reducing a durability of the device. <P>SOLUTION: The fuel injection device 10 includes the delivery pipe 11 and the four fuel injection valves 12, of which one ends 12a provided with an injection port 15, respectively, are fixed to a cylinder head 2, and other ends 12b are connected with the delivery pipe 11 via an adopter 13, respectively. The adopter 13 includes a cylindrical downstream end part 18 fitted into a connecting hole 16 formed at the other end 12b of the fuel injection valve 12, and a cylindrical upstream end part 17 fitted into a connecting hole 11a formed in the delivery pipe 11. The upstream end part 17 is provided to the adopter 13 so that a center line CL1 thereof is parallel to a center line CL2 of the downstream end part 18 and is offset in a radially outer direction to the center line CL2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel injection device for an internal combustion engine including a pressure accumulation chamber in which pressurized fuel is stored, and a plurality of fuel injection valves having one end fixed to a cylinder head and the other end connected to the pressure accumulation chamber.

  There is known a fuel injection device in which fuel is pressurized and stored in a delivery pipe, and the pressurized fuel is injected from a plurality of fuel injection valves connected to the delivery pipe. In such a fuel injection device, the fuel receiving portion provided in the delivery pipe and the fuel injection valve are connected by a bellows member, and the moving direction of the fuel receiving portion intersects the axis of the fuel injection device outside the bellows member. It is known that a pipe for restricting in the direction to be provided is provided to ensure a fuel seal when an axial deviation occurs between the connection portion of the delivery pipe and the fuel injection valve (see Patent Document 1). ). In addition, there are Patent Documents 2 and 3 as prior art documents related to the present invention.

JP 2008-121604 A JP 2001-90631 A JP 2002-195126 A

  As is well known, the bellows member has a thin tube wall so that it can be deformed when a force is applied. Therefore, when a bellows member is provided between the delivery pipe and the fuel injection valve as in the device of Patent Document 1, the rigidity of the bellows member portion is lower than that of the other portions. Therefore, the durability of the device may be reduced.

  In view of the above, an object of the present invention is to provide a fuel injection device for an internal combustion engine that can tolerate an axial deviation that occurs between a delivery pipe and a fuel injection valve without reducing the durability of the device.

  The fuel injection device for an internal combustion engine according to the present invention has a pressure accumulation chamber for storing pressurized fuel, one end provided with an injection port fixed to a common cylinder head, and the other end via a joining member. A plurality of fuel injection valves respectively connected to the pressure accumulating chamber, and the joining member is a cylindrical injection valve side end portion fitted in a connection hole provided at the other end of the fuel injection valve; A cylindrical pressure accumulation chamber side end fitted in a connection hole provided in the pressure accumulation chamber, and the center line of the pressure accumulation chamber side end is parallel to the center line of the injection valve side end, And it is provided in the said joining member so that it may be offset to the radial direction outer side with respect to the centerline of the said injection valve side edge part (Claim 1).

  According to the fuel injection device of the present invention, since the center line of the pressure accumulating chamber side end is offset radially outward with respect to the center line of the injection valve side end, the injection valve side end is connected to the fuel injection valve. The position of the pressure accumulating chamber side end can be changed by rotating the joining member in a state of being fitted into the pressure accumulating chamber. Therefore, even if an axial deviation occurs between the delivery pipe and the fuel injection valve, the axial deviation can be allowed by adjusting the position of the pressure accumulating chamber side end by rotating the joining member. Further, in the fuel injection device according to the present invention, since the shaft misalignment generated between the delivery pipe and the fuel injection valve can be allowed without using the bellows member having low rigidity, it is possible to prevent the rigidity of this portion from being lowered. . Therefore, it can prevent that durability of an apparatus falls.

  As described above, according to the fuel injection device for an internal combustion engine of the present invention, by rotating the joining member and adjusting the position of the pressure accumulating chamber side end portion of the joining member, the delivery pipe, the fuel injection valve, Misalignment between the two can be allowed. For this reason, it is possible to allow an axial deviation generated between the delivery pipe and the fuel injection valve without deteriorating the durability of the apparatus.

The figure which shows the principal part of the internal combustion engine in which the fuel-injection apparatus which concerns on one form of this invention was integrated. The figure which shows the fixed state of a delivery pipe. The figure which expands and shows a fuel injection valve. The figure which expands and shows an adapter. The figure for demonstrating the range which can move the upstream edge part of the adapter in the state which inserted the downstream edge part of the adapter in the fuel injection valve. The figure which shows a fuel-injection apparatus when an axial shift arises between a delivery pipe and a fuel injection valve.

  FIG. 1 shows a main part of an internal combustion engine in which a fuel injection device according to one embodiment of the present invention is incorporated. An internal combustion engine 1 in FIG. 1 is mounted on a vehicle as a driving power source, and includes four cylinders (not shown) and a cylinder head 2. Cylinder numbers # 1 to # 4 are assigned to the cylinders from one end to the other end in the arrangement direction to distinguish these cylinders. The cylinder head 2 is provided with an intake port (not shown) for each cylinder.

  The internal combustion engine 1 is provided with a fuel injection device 10. The fuel injection device 10 includes a delivery pipe 11 as a pressure accumulation chamber, four fuel injection valves 12, and an adapter 13 as a joining member that connects the delivery pipe 11 and the fuel injection valve 12. In the cylinder head 2, a communication hole 2a communicating with the cylinder is provided for each cylinder. As shown in this figure, the four communication holes 2 a are provided in a line in the cylinder head 2. Each fuel injection valve 12 has its one end 12a inserted and fixed into a different communication hole 2a. These four fuel injection valves 12 are connected to the same delivery pipe 11 via an adapter 13. Each fuel injection valve 12 is attached to the cylinder head 2 by being pressed against the cylinder head 2 by the delivery pipe 11. As shown in FIG. 2, the delivery pipe 11 is fixed to the cylinder head 2 with bolts 14. Fuel is pressurized and sent to the delivery pipe 11 from a fuel tank (not shown) through a high-pressure pump (not shown). The pressurized fuel is stored in the delivery pipe 11. The fuel in the delivery pipe 11 is sent from the delivery pipe 11 to the fuel injection valve 12 through the adapter 13 when the fuel injection valve 12 is opened, and then directly injected into the cylinder from the fuel injection valve 12. . That is, the internal combustion engine 1 is configured as an in-cylinder direct injection internal combustion engine in which fuel is directly injected into the cylinder.

  FIG. 3 shows an enlarged view of the fuel injection valve 12 of the # 1 cylinder. In the following, the fuel injection valve 12 of the # 1 cylinder will be described, but the same applies to the fuel injection valves 12 of the other cylinders. An injection port 15 is provided at one end 12 a of the fuel injection valve 12. As described above, the fuel injection valve 12 has one end 12 a inserted into the communication hole 2 a of the cylinder head 2 and fixed to the cylinder head 2. A Teflon (registered trademark) seal 14 is provided around one end 12 a of the fuel injection valve 12. The Teflon (registered trademark) seal 14 is interposed between the fuel injection valve 12 and the cylinder head 2, and closes the gap between the fuel injection valve 12 and the cylinder head 2. The other end 12b of the fuel injection valve 12 is provided with a connection hole 16 into which the adapter 13 is fitted. In the center of the bottom surface of the connection hole 16, an introduction hole 16 a for introducing fuel into the fuel injection valve 12 is opened. The internal structure of the fuel injection valve 12 is the same as that of a well-known fuel injection valve provided in the internal combustion engine, and a description thereof will be omitted.

  The delivery pipe 11 is provided with a connection hole 11a into which the adapter 13 is fitted. As described above, since four fuel injection valves 12 are connected to the delivery pipe 11, four connection holes 11a are provided. These four connection holes 11a are provided in a row in the delivery pipe 11. At the center of the bottom surface of each connection hole 11a, a discharge hole (not shown) communicating with the inside of the delivery pipe 11 is opened.

  FIG. 4 shows the adapter 13 in an enlarged manner. The adapter 13 includes an upstream end 17 as a pressure accumulation chamber side end fitted into the connection hole 11 a of the delivery pipe 11 and a downstream end as an injection valve side end fitted into the connection hole 16 of the fuel injection valve 12. 18 and a fuel passage 19 penetrating through the adapter 13 from the upper end surface 17a of the upstream end portion 17 to the lower end surface 18a of the downstream end portion 18. The upstream end 17 has a cylindrical shape, and an O-ring 20 is provided on the outer peripheral surface thereof. Similarly, the downstream end 18 is cylindrical, and an O-ring 21 is provided on the outer peripheral surface thereof. As shown in this figure, the upstream end 17 and the downstream end 18 are provided on the adapter 13 so that their outer diameters are substantially the same. Further, as shown in this figure, the upstream end portion 17 is offset by an offset amount S in the center line CL1 parallel to the center line CL2 of the downstream end portion 18 and radially outward with respect to the center line CL2. As shown, the adapter 13 is provided. Therefore, the upstream end portion 17 is provided at a position where the center is shifted radially outward with respect to the downstream end portion 18, whereby the adapter 13 is formed in a crank shape. The fuel passage 19 includes an upstream fuel passage 19a provided on the center line CL1 of the upstream end portion 17, and a downstream fuel passage 19b provided on the center line CL2 of the downstream end portion 18. The upstream fuel passage 19 a and the downstream fuel passage 19 b are connected in the adapter 13.

  Since the adapter 13 is thus formed in a crank shape, the adapter 13 is rotated about the center line CL2 with the downstream end 18 inserted into the fuel injection valve 12, so that the upstream end 17 The position of the center line CL1 can be changed. As described above, since the center line CL1 of the upstream end portion 17 is separated from the center line CL2 of the downstream end portion 18 by the offset amount S radially outward, as shown in FIG. By rotating around CL2, the center line CL1 of the upstream end portion 17 can be changed on the circle C with the offset amount S as the radius. Therefore, the O-ring 20 of the upstream end 17 can be disposed at any one of the positions P1, P2, and P3 in FIG. 5 with respect to the O-ring 21 of the downstream end 18, for example. Further, the attachment position of the delivery pipe 11 to the cylinder head 2 can be changed by rotating the adapter 13 about the center line CL2. Therefore, as shown in FIG. 2, the inner diameter Dh of the bolt hole 11b of the delivery pipe 11 is set to a value obtained by adding a value obtained by doubling the offset amount S to the outer diameter Db of the bolt 14. By setting the inner diameter Dh of the bolt hole 11b to such a value, the attachment position of the delivery pipe 11 can be changed.

  According to the fuel injection device 10 of the present embodiment, since the adapter 13 has a crank shape, the adapter 13 is rotated or the delivery pipe 11 is moved to move between the delivery pipe 11 and the fuel injection valve 12. The generated axis deviation can be allowed within the range of the offset amount S. Specifically, for example, as shown in FIG. 6, the connection hole 11 a corresponding to the fuel injection valve 12 of the # 3 cylinder among the four connection holes 11 a provided in the delivery pipe 11 is from the position where it should be originally processed. In the case where the processing is shifted, the adapter 13 is rotated to change the position of the upstream side end portion 17, so that the upstream side of the adapter 13 is inserted into the shifted connection hole 11 a without tilting the fuel injection valve 12. The side end portion 17 can be fitted.

  Further, in the fuel injection device 10 of the present embodiment, the crank-shaped adapter 13 copes with the shaft misalignment, so that the rigidity of this portion can be prevented from being lowered. Therefore, it is possible to prevent the durability of the fuel injection device 10 from being lowered.

  The present invention is not limited to the above-described form and can be implemented in various forms. For example, the internal combustion engine to which the present invention is applied is not limited to a direct injection internal combustion engine that directly injects fuel into a cylinder. For example, the present invention may be applied to a so-called port injection type internal combustion engine in which fuel is injected into an intake port. Moreover, you may apply this invention to the common rail provided in a diesel internal combustion engine. Furthermore, the present invention may be applied to various internal combustion engines, such as a V-type internal combustion engine, in which cylinders are arranged in one direction on a cylinder head.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cylinder head 10 Fuel injection apparatus 11 Delivery pipe (pressure accumulation chamber)
11a Connection hole 12 Fuel injection valve 12a One end 12b The other end 13 Adapter (joining member)
15 injection port 16 connection hole 17 upstream side end (pressure accumulation chamber side end)
18 Downstream end (injection valve end)
CL1 Center line at the upstream end CL2 Center line at the downstream end

Claims (1)

A plurality of pressure accumulation chambers in which pressurized fuel is stored, and one end where an injection port is provided are fixed to a common cylinder head, and the other end is connected to the pressure accumulation chamber via a joining member. A fuel injection valve,
The joining member includes a cylindrical injection valve side end fitted into a connection hole provided at the other end of the fuel injection valve, and a cylindrical pressure accumulation chamber side end fitted into a connection hole provided in the pressure accumulation chamber. And
The pressure accumulating chamber side end is parallel to the center line of the injection valve side end and offset to the outer side in the radial direction with respect to the center line of the injection valve side end. A fuel injection device for an internal combustion engine provided.

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