Fuel injector

Abstract

To provide a fuel injection valve connected to a connection pipe of a fuel pipe by a holder with an aligning function.SOLUTION: A fuel injection valve 1 with a holder 3 is energized toward an engine side by receiving energizing force from the holder 3, and attached to a connection pipe 2 of a fuel pipe. The holder 3 includes a plurality of first curved parts 31 that abut against the connection pipe 2 of the fuel pipe, and a plurality of second curved parts that abut against the fuel injection valve 1. The first curved parts 31 are displaced to the outside in a radial direction around a center axis 1a by having the holder 3 pressed in a direction along the center axis 1a of the fuel injection valve 1. The second curved parts are displaced to the inside in the radial direction around the center axis 1a by having the holder 3 pressed in the direction along the center axis 1a.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a fuel injection valve that injects fuel.

Background Art

[0002] A holding device provided between a fuel injection valve and a connecting pipe, which presses and holds the fuel injection valve in a housing hole of a cylinder head, is described in Patent Document 1. This holding device is configured as a punched and bent part and has a partially ring-shaped base element, from which a holding bracket is bent and extended. And the holding bracket abuts on the downstream end face of the connecting pipe in the incorporated state (see paragraph 0018).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When connecting a direct injection type fuel injection valve (DI injector) that directly injects fuel into a cylinder to a connecting pipe of a fuel pipe, the fuel injection valve is urged toward the engine side via a holder (the holding device of Patent Document 1) so that the fuel injection valve does not float from the engine side due to fuel pressure fluctuations during operation. Here, due to the mounting relationship against the fuel pressure, within the movable range due to deformation of the O-ring arranged at the connection part between the fuel injection valve and the connecting pipe, there was a possibility that it was held in a state deviated from the central axis of the connecting pipe.

[0005] In Patent Document 1, no consideration is given to providing the holder (holding device) with a centering (alignment) function for aligning the central axis of the connecting pipe and the central axis of the fuel injection valve.

[0006] The object of the present invention is to provide a fuel injection valve connected to a fuel piping connection pipe with a holder having an alignment function. [Means for solving the problem]

[0007] To achieve the above objective, the fuel injection valve of the present invention is A fuel injector having a holder, which is biased toward the engine by a biasing force from the holder and attached to a connecting pipe of the fuel line, The holder comprises a plurality of first curved portions that abut against the connecting pipe of the fuel piping, and a plurality of second curved portions that abut against the fuel injection valve. The first curved portion is displaced radially outward with respect to the central axis when the holder is pressed in a direction along the central axis of the fuel injection valve. The second curved portion is configured to be displaced radially inward with respect to the central axis when the holder is pressed in a direction along the central axis. [Effects of the Invention]

[0008] According to the present invention, the centering function of the holder allows the central axis of the fuel injector to be aligned with the central axis of the connecting pipe of the fuel line, thereby enabling connection of the fuel injector to the connecting pipe of the fuel line. As a result, assembly of the fuel injector into the engine becomes easier. [Brief explanation of the drawing]

[0009] [Figure 1] This is an external view of a fuel injection valve according to one embodiment of the present invention. [Figure 2] This is a perspective view showing the appearance of a holder according to one embodiment of the present invention. [Figure 3] Figure 2 is a top view of the holder, seen from above. [Figure 4] This is a side view of the holder shown in Figure 2, seen from the side. [Figure 5] Figure 2 is a cross-sectional view showing the fuel injection valve connected to the fuel piping's connecting pipe using the holder. [Figure 6]Figure 2 is a cross-sectional view (viewed from a different direction than Figure 5) showing the fuel injector connected to the fuel piping using the holder shown in Figure 2. [Figure 7] This is a perspective view showing the appearance of a modified holder according to one embodiment of the present invention. [Figure 8] Figure 7 is a cross-sectional view showing the fuel injector connected to the fuel piping using the holder. [Modes for carrying out the invention]

[0010] One embodiment of the present invention will be described with reference to the drawings.

[0011] The configuration of the fuel injection valve 1 will be described with reference to Figure 1. Figure 1 is an external view of a fuel injection valve 1 according to one embodiment of the present invention.

[0012] 1a represents the central axis of the fuel injector 1, and 2a represents the central axis of the connecting pipe 2 of the fuel piping. In Figure 1, for clarity, the central axes 1a and 2a are drawn to pass outside the fuel injector 1 and connecting pipe 2, respectively, but in reality, central axis 1a passes inside the fuel injector 1, and central axis 2a passes inside the connecting pipe 2.

[0013] The central axis 1a of the fuel injector 1 coincides with the axis of a movable element (movable element axis) located inside the fuel injector 1 (not shown). The movable element is a movable component on which a valve body (not shown) is integrally attached, and the movable element axis is sometimes called the valve axis.

[0014] In Figure 1, the upper end (upper side) will be referred to as the base end (base side), and the lower end (lower side) will be referred to as the tip end (tip side). The designations of the base end (base side) and tip end (tip side) are based on the direction of fuel flow. That is, fuel flows from the upper end (base end) to the lower end (tip end) of the fuel injector 1. The vertical relationship described herein is defined based on Figure 1 and does not necessarily coincide with the vertical direction when the fuel injector 1 is mounted on an internal combustion engine.

[0015] A fuel supply port 11 (see FIG. 5) is provided at the base end of the fuel injection valve 1, and a fuel injection hole 12 is provided at the tip end of the fuel injection valve 1. The fuel that flows into the interior of the fuel injection valve 1 from the fuel supply port 11 flows toward the tip end of the fuel injection valve 1 and is injected outside the fuel injection valve 1 from the fuel injection hole 12.

[0016] A valve portion composed of a valve body and a valve seat (not shown) is formed at the tip end of the fuel injection valve 1. The opening and closing of the fuel passage are performed by the valve body coming into contact with and separating from the valve seat. That is, when the valve body contacts the valve seat, the fuel passage is closed and fuel injection stops, and when the valve body separates from the valve seat, the fuel passage is opened and fuel injection is performed.

[0017] The fuel injection valve 1 of this embodiment is an electromagnetic drive type fuel injection valve, and an electromagnetic drive unit (not shown) is provided at an intermediate portion in the direction along the central axis 1a of the fuel injection valve 1. The electromagnetic drive unit includes a fixed iron core, a movable iron core provided on a mover, an electromagnetic coil, and a spring that biases the mover in the valve closing direction. By energizing the electromagnetic coil, an electromagnetic force acts between the fixed iron core and the movable iron core, and the mover provided with the movable iron core is attracted toward the fixed iron core side. At this time, the valve body provided on the mover separates from the valve seat and opens, and fuel injection is performed. When the energization of the electromagnetic coil is stopped, the electromagnetic force acting between the fixed iron core and the movable iron core disappears, the mover is pushed back in the valve closing direction by the spring, and the valve body provided on the mover contacts the valve seat and closes.

[0018] A connector 13 to which an external wiring is connected to energize the electromagnetic coil is provided on the fuel injection valve 1. The connector 13 is integrally formed with a resin cover (resin molding portion) 14 that covers the outer surface of the fuel injection valve 1 by a resin material.

[0019] A metal nozzle portion 15 is provided on the tip side of the fuel injector 1 relative to the resin cover 14. The fuel injection hole 12 is located at the tip of the nozzle portion 15. A sealing member 16 is provided on the narrow diameter portion 15a of the nozzle portion 15. The narrow diameter portion 15a of the nozzle portion 15 is inserted into an insertion hole provided in the engine, and the sealing member 16 seals the fuel injector 1 and the inner circumferential surface of the insertion hole to maintain airtightness and liquid tightness.

[0020] The fuel injector 1 is biased toward the engine by the holder 3' when the narrow-diameter portion 15a of the nozzle portion 15 is inserted into an insertion hole provided in the engine, and the fuel supply port 11 (see Figure 5) is inserted into the connecting pipe 2 of the fuel piping. At this time, the fuel injector 1 is pressed toward the engine by the holder 3' so that the lower end surface 15c of the large-diameter portion 15b abuts against the engine.

[0021] The fuel injector 1 is subjected to a force that causes it to lift away from the engine due to fuel pressure fluctuations during operation. At this time, the holder 3' prevents or suppresses the fuel injector 1 from lifting away from the engine by biasing it toward the engine.

[0022] Various forms of electromagnetic drive mechanisms for fuel injectors are known, and the fuel injector 1 can be configured in various ways in addition to the configuration described above. Furthermore, the drive mechanism for the movable element, i.e., the drive mechanism for the valve body, of the fuel injector 1 is not limited to an electromagnetic drive type, and other drive methods can be employed.

[0023] Next, the configuration of the holder 3 of this embodiment will be described with reference to Figures 2 to 4. Figure 2 is a perspective view showing the external appearance of the holder 3 according to one embodiment of the present invention. Figure 3 is a top view of the holder 3 of Figure 2, seen from above. Figure 4 is a side view of the holder 3 of Figure 2, seen from the side. Note that the holder 3' shown in Figure 1 is a holder that does not have a self-aligning function, while the holder (pressing member) 3 shown in Figures 2 to 4 has a self-aligning function and has a different form from the holder 3'.

[0024] This embodiment focuses on a direct injection type fuel injector (DI injector) that directly injects fuel into the engine cylinder. The direct injection type fuel injector 1 is connected to a connecting pipe 2 of the high-pressure fuel piping and supplied with high-pressure fuel. Due to fuel pressure fluctuations during operation, it is subjected to a strong force that causes it to lift away from the engine. The holder 3 is used when attaching the fuel injector 1 to the connecting pipe 2 of the high-pressure fuel piping and biases the fuel injector 1 toward the engine to prevent it from lifting away from the engine due to fuel pressure fluctuations during operation.

[0025] The holder 3 performs a centering function by contacting the connecting pipe 2 side and the fuel injector 1 side of the high-pressure fuel piping, respectively, to align the central axis 2a of the connecting pipe 2 with the central axis 1a of the fuel injector 1. The portion that contacts the connecting pipe 2 side is composed of multiple curved sections (first curved section) 31. The portion that contacts the fuel injector 1 side is also composed of multiple curved sections (second curved section) 32. The first curved section 31 and the second curved section 32 are connected by an axial extension section 33. In other words, the holder 3 has a first curved section 31, a second curved section 32, and an axial extension section 33.

[0026] The first curved portion 31 has a curved shape that is convex radially outward with respect to the central axis 1a, and multiple first curved portions are provided along the circumferential direction C1 with respect to the central axis 1a. In this embodiment, two first curved portions 31 are provided along the circumferential direction C1, and the two first curved portions 31a and 31b are arranged to face each other with respect to the central axis 1a. That is, the holder 3 of this embodiment has a pair of first curved portions 31a and 31b arranged to face each other with respect to the central axis 1a. The first curved portion 31 (31a, 31b) of this embodiment is composed of an arc-shaped portion (first arc-shaped portion) with curvature C31. In this embodiment, the first arc-shaped portion 31 has a constant curvature C31, but the curvature C31 does not need to be constant and may vary along the circumferential direction C1.

[0027] The second curved portion 32 has a curved shape that is convex radially outward with respect to the central axis 1a, and multiple portions are provided along the circumferential direction C2 with respect to the central axis 1a. In this embodiment, two second curved portions 32 are provided along the circumferential direction C2, and the two second curved portions 32a and 32b are arranged to face each other with respect to the central axis 1a. That is, the holder 3 of this embodiment has a pair of second curved portions 32a and 32b arranged to face each other with respect to the central axis 1a. The second curved portion 32 (32a, 32b) of this embodiment is composed of an arc-shaped portion (second arc-shaped portion) with curvature C32. In this embodiment, the second arc-shaped portion 32 has a constant curvature C32, but the curvature C32 does not need to be constant and may vary along the circumferential direction C2.

[0028] The axial extension 33 extends in a direction along the central axis 1a of the fuel injector 1 and connects the first curved portion 31 and the second curved portion 32. The axial extension 33 is made of a material with excellent toughness and contributes to generating a biasing force that biases the fuel injector 1 toward the engine (biasing function), and also exhibits a centering function by changing the radial relative position of the first curved portion 31 and the second curved portion. The biasing function and centering function will be explained in detail later.

[0029] The first curved section 31 is connected to the axially extended section 33 by a bent section 34. That is, a bent section 34 is provided between the first curved section 31 and the axially extended section 33. Specifically, bent sections 34a and 34b are provided at both ends of one of the pair of first curved sections 31a, 31b, and the first curved section 31a is connected to the axially extended section 33a by the bent section 34a and to the axially extended section 33b by the bent section 34b. Bend sections 34c and 34d are provided at both ends of the other first curved section 31b, 31b, and the first curved section 31b is connected to the axially extended section 33c by the bent section 34c and to the axially extended section 33d by the bent section 34d.

[0030] The second curved section 32 is connected to the axially extended section 33 by a bent section 35. That is, a bent section 35 is provided between the second curved section 32 and the axially extended section 33. Specifically, bent sections 35a and 35b are provided at both ends of one of the pair of second curved sections 32a, 32b, and the second curved section 32a is connected to the axially extended section 33d by the bent section 35a and to the axially extended section 33a by the bent section 35b. Bend sections 35c and 35d are provided at both ends of the other second curved section 32b, and the second curved section 32b is connected to the axially extended section 33b by the bent section 35c and to the axially extended section 33c by the bent section 35d.

[0031] The holder 3 is composed of a continuous, integrated linear or plate-like member, with the first curved portion 31, the second curved portion 32, the axially extended portion 33, and the bent portion 35 connected in the order of axially extended portion 33a, bent portion 34a, first curved portion 31a, bent portion 34b, axially extended portion 33b, bent portion 35c, second curved portion 32a, bent portion 35d, axially extended portion 33c, bent portion 34c, first curved portion 31b, bent portion 34d, axially extended portion 33d, bent portion 35a, second curved portion 32a, bent portion 35b, and axially extended portion 33a. Such a holder 3 can be formed by bending a ring-shaped member (annular member) for example using a press, and can be manufactured inexpensively and quickly.

[0032] The holder 3 can also be formed by bending a single straight member, but in this case, the bending process must be carried out so that both ends of the straight member are not located at least in the axially extended portion 33 and the curved portions 34 and 35. If both ends of the straight member are located in the axially extended portion 33 and the curved portions 34 and 35, there is a risk that the biasing function and centering function described above will not be fully performed.

[0033] As shown in Figure 3, in the holder 3 alone, the diameter φ31 of the first curved portion 31 is larger than the diameter φ32 of the second curved portion 32. That is, the radius of curvature R31 of the first curved portion 31 is larger than the radius of curvature R32 of the second curved portion 32. Therefore, the curvature of the first curved portion 31 is smaller than the curvature of the second curved portion 32. In other words, the radius of curvature R32 of the second curved portion 32 is smaller than the radius of curvature R31 of the first curved portion 31, and the curvature of the second curved portion 32 is larger than the curvature of the first curved portion 31. As shown in Figure 4, the height dimension of the holder 3 alone is H3.

[0034] Next, the mounting structure of the fuel injector 1 using the holder 3 will be described with reference to Figures 5 and 6. Figure 5 is a cross-sectional view showing the fuel injector 1 connected to the fuel piping connection pipe 2 with the holder 3 of Figure 2. Figure 6 is a cross-sectional view (viewed from a different direction than Figure 5) showing the fuel injector 1 connected to the fuel piping connection pipe 2 with the holder 3 of Figure 2.

[0035] When the fuel injector 1 is installed on the engine, the fuel injector 1 is assembled with the fuel supply port 11 inserted into the connecting pipe 2 of the fuel line, and sandwiched between the connecting pipe 2 of the fuel line and the engine. At this time, the connecting pipe 2 has a hole 21 that forms a fuel passage, and the fuel supply port 11 is inserted into the inside of the hole 21 from the opening 21a of the hole 21, which is the outlet of the fuel passage.

[0036] The holder 3 is held between the connecting pipe 2 and the fuel injector 1, and as a reaction force, biases the fuel injector 1 toward the engine side with respect to the connecting pipe 2. At this time, the first curved portion 31 of the holder 3 abuts against the connecting pipe 2 side, and the second curved portion 32 abuts against the fuel injector 1 side.

[0037] The connecting pipe 2 has a connecting pipe-side clamping portion 22 that clamps the holder 3 between itself and the fuel injection valve 1, and a connecting pipe-side radial displacement restricting portion 23a that restricts the radially outward displacement of the first curved portion 31 of the holder 3. The connecting pipe-side clamping portion 22 is made up of the end face 22 in which the opening 21a of the hole 21 is formed, and is located on the outer circumference side of the opening 21a, i.e., the outlet opening surface 21a of the fuel passage 21. The connecting pipe-side radial displacement restricting portion 23a is made up of an outer peripheral wall 23 that protrudes from the outer circumference of the end face 22 in which the opening 21a of the hole 21 is formed, in a direction along the central axis 2a of the connecting pipe 2.

[0038] The fuel injector 1 has a fuel injector-side clamping portion 14a that clamps the holder 3 between itself and the connecting pipe 2, and a fuel injector-side radial displacement restricting portion 11a that restricts the radially inward displacement of the second curved portion 32 of the holder 3. The fuel injector-side clamping portion 14a is formed from the fuel supply port side end (base end) 14a of the resin cover 14. The fuel injector-side radial displacement restricting portion 11a is formed from the outer circumferential portion (outer circumferential surface) of the fuel supply port 11.

[0039] The holder 3 is supported by the connecting pipe 2 in the direction along the central axis 1a by the connecting pipe 2, with its first curved portion 31 in contact with the end face 22 of the connecting pipe 2 in a direction along the central axis 2a, and in a direction perpendicular to the central axis 2a (radial direction), by the inner circumferential surface 23a of the outer circumferential wall 23 of the connecting pipe 2. The other end of the holder 3 in the direction along the central axis 1a is supported by the fuel injector 1, with its second curved portion 32 in contact with the end face 14a of the resin cover 14 in a direction along the central axis 1a, and in a direction perpendicular to the central axis 1a (radial direction), by the outer circumferential surface 11a of the fuel supply port 11.

[0040] When the fuel injector 1 is assembled to the engine and fuel piping, the distance H between the end face 22 of the connecting pipe 2 and the end 14a of the resin cover 14 of the fuel injector 1 is smaller than the height dimension H3 of the holder 3 alone shown in Figure 4. When the fuel injector 1 is assembled to the engine and fuel piping, the holder 3 is pressed in a direction along the central axis 1a of the fuel injector 1. At this time, as shown in Figure 5, the first curved portion 31 of the holder 3 is displaced to widen radially outward and comes into contact with the radial displacement restricting portion 23a on the connecting pipe side, thereby restricting its radially outward displacement. On the other hand, as shown in Figure 6, the second curved portion 32 is displaced to narrow radially inward and comes into contact with the radial displacement restricting portion 11a on the fuel injector side, thereby restricting its radially inward displacement. As a result, the holder 3 aligns the fuel injector 1 so that its central axis 1a coincides with the central axis 2a of the connecting pipe 2. This suppresses the deviation of the fuel injector 1 from the central axis 2a of the connecting pipe 2. In addition, when this alignment is performed, the holder 3 generates a biasing force that biases the fuel injector 1 toward the engine side.

[0041] An O-ring 19 is provided on the outer circumference of the fuel supply port 11, and the fuel injection valve 1 can be displaced to a position offset from the central axis 2a of the connecting pipe 2 within the deformation range of the O-ring. In this embodiment, the alignment function described above makes it possible to suppress the misalignment between the central axis 1a of the fuel injection valve 1 and the central axis 2a of the connecting pipe 2.

[0042] When the fuel injector 1 is assembled to the engine and fuel piping, the first curved portion 31 of the holder 3 expands radially outward, so the first curved portion 31 after assembly is shifted radially outward from its position as a standalone unit, and R31 (see Figure 3) becomes larger than its value as a standalone unit. On the other hand, the second curved portion 32 narrows radially inward, so the second curved portion 32 after assembly is shifted radially inward from its position as a standalone unit, and R32 (see Figure 3) becomes smaller than its value as a standalone unit. Note that R31 after assembly is the radius of the part of the first curved portion 31 that is located radially outward, and does not necessarily coincide with the radius of curvature of the first curved portion 31. Also, R32 after assembly is the radius of the part of the second curved portion 32 that is located radially inward, and does not necessarily coincide with the radius of curvature of the second curved portion 32.

[0043] Next, examples of modifications to the holder 3 will be described with reference to Figures 7 and 8. Figure 7 is a perspective view showing the appearance of an example of a modification to the holder 3 according to one embodiment of the present invention. Figure 8 is a cross-sectional view showing the state in which the fuel injection valve 1 is connected to the fuel piping connection pipe 2 with the holder 3 of Figure 7.

[0044] In this example, the holder 3 is formed by bending a single linear or plate-shaped member having both ends. In this case, both ends of the linear member are brought together at the first curved portion 31 and further extended radially outward.

[0045] Specifically, one end portion of a linear or plate-shaped member forms half 31a1 of the first curved portion 31a, and the other end portion of the member forms the remaining half 31a2 of the first curved portion 31a. The end portion constituting portion 31a1 of the first curved portion 31a is extended radially outward at its tip to form an extended portion 31a11, and the other end portion constituting portion 31a2 of the first curved portion 31a is extended radially outward at its tip to form an extended portion 31a21.

[0046] In Figure 7, the extended portions 31a11 and 31a21 are formed on the first curved portion 31a, but the extended portions 31a11 and 31a21 may also be formed on the other first curved portion 31b. Furthermore, it is not necessary to form the extended portions 31a11 and 31a21 on both ends of a single linear or plate-like member; either the extended portion 31a11 or 31a21 may be formed on the tip of either end.

[0047] The extension portions 31a11 and 31a21 are inserted into locking portions 24 formed in the outer peripheral wall 23 of the connecting pipe 2. The locking portions 24 are composed of through holes that penetrate the outer peripheral wall 23 radially. By inserting and locking the extension portions 31a11 and 31a21 into the locking portions 24, the mounting angle of the holder 3 in the circumferential direction can be set to a constant angle. By defining the mounting angle of the holder 3 in the circumferential direction relative to the fuel injector 1, the mounting angle of the fuel injector 1 in the circumferential direction relative to the connecting pipe 2 can be set to a constant angle.

[0048] In the embodiments and modifications described above, examples were given in which two first curved sections 31 and two second curved sections 32 are provided, but each may be provided in three or more sections. Also, although examples were given in which the first curved sections 31 and two second curved sections 32 are evenly arranged in the circumferential direction, they may be unevenly arranged in the circumferential direction. The number and arrangement of the first curved sections 31 and two second curved sections 32 should be such that the alignment function of the fuel injection valve 1 can be obtained.

[0049] The above-described embodiments and modifications have the following characteristics. (1) A fuel injection valve 1 having a holder 3, which is biased toward the engine by a biasing force from the holder 3 and attached to the connecting pipe 2 of the fuel line, The holder 3 comprises a plurality of first curved portions 31 that abut against the connecting pipe 2 of the fuel piping, and a plurality of second curved portions 32 that abut against the fuel injection valve 1. The first curved portion 31 is displaced radially outward with respect to the central axis 1a as the holder 3 is pressed in a direction along the central axis 1a of the fuel injection valve 1. The second curved portion 32 is configured to be displaced radially inward with respect to the central axis 1a when the holder 3 is pressed in a direction along the central axis 1a.

[0050] (2) The holder 3 has a pair of first curved portions 31, a pair of second curved portions 32, and a plurality of axial extensions 33 that extend in a direction along the central axis 1a and connect the first curved portions 31 and the second curved portions 32.

[0051] (3) The dimension H3 of the holder 3 in the direction along the central axis 1a is greater than the dimension H when the fuel injector 1 is assembled to the engine.

[0052] (4) The first curved portion 31 is displaced radially outward, so that it comes into contact with the connecting pipe side radial displacement restricting portion 23a provided on the connecting pipe 2 of the fuel piping, and its radially outward displacement is restricted. The second curved portion 32 is displaced radially inward, causing it to come into contact with the fuel injector side radial displacement restricting portion 11a provided on the fuel injector 1, thereby restricting its radial inward displacement.

[0053] (5) The holder 3 is composed of a single linear member or plate-shaped member.

[0054] (6) The holder 3 has an extended portion 31a11, 31a21 on the first curved portion 31 or the second curved portion 32 that extends radially outward and engages with an engaging portion provided on the connecting pipe of the fuel piping.

[0055] (7) The holder 3 is composed of a single linear or plate-shaped member having both ends, A portion of the first curved portion 31 or the second curved portion 32 is formed at one end of the linear member or plate-shaped member, and the other portion of the first curved portion 31 or the second curved portion 32 is formed at the other end of the linear member or plate-shaped member. The tip of at least one end portion of either one end portion or the other end portion is extended radially outward to form the extended portions 31a11 and 31a21. [Explanation of Symbols]

[0056] 1...Fuel injector, 1a...Central axis of fuel injector 1, 2...Connecting pipe for fuel piping, 3...Holder, 11a...Radial displacement restricting section on the fuel injector side, 23a...Radial displacement restricting section on the connecting pipe side, 31...First curved section, 31a11, 31a21...Extended section, 32...Second curved section, 33...Axial extension section, H...Dimensions of holder 3 when fuel injector 1 is assembled to the engine, H3...Dimensions of holder 3 as a standalone unit.

Claims

1. A fuel injector having a holder, which is biased toward the engine by a biasing force from the holder and attached to a connecting pipe of the fuel line, The holder comprises a plurality of first curved portions that abut against the connecting pipe of the fuel piping, and a plurality of second curved portions that abut against the fuel injection valve. The first curved portion is displaced radially outward with respect to the central axis when the holder is pressed in a direction along the central axis of the fuel injection valve. The second curved portion of the fuel injection valve is configured to be displaced radially inward with respect to the central axis when the holder is pressed in a direction along the central axis.

2. In the fuel injection valve according to claim 1, The holder is a fuel injection valve having a pair of first curved portions, a pair of second curved portions, and a plurality of axial extensions extending in a direction along the central axis and connecting the first curved portions and the second curved portions.

3. In the fuel injection valve according to claim 2, The holder is a fuel injector whose dimensions in the direction along the central axis are greater than the dimensions of the fuel injector when it is assembled to the engine.

4. In the fuel injection valve according to claim 3, The first curved portion, by being displaced radially outward, comes into contact with a radial displacement restricting portion on the connecting pipe side provided on the connecting pipe of the fuel piping, and its radially outward displacement is restricted. The second curved portion is displaced radially inward, causing it to contact a fuel injector-side radial displacement restricting portion provided on the fuel injector, thereby restricting the radially inward displacement of the fuel injector.

5. In the fuel injection valve according to claim 2, The holder is a fuel injection valve composed of an integral linear member or plate-shaped member.

6. In the fuel injection valve according to claim 2, The holder is a fuel injection valve having an extended portion on one of the pair of first curved portions that extends radially outward and engages with an engaging portion provided on the connecting pipe of the fuel piping.

7. In the fuel injection valve according to claim 6, The holder is composed of a single linear or plate-shaped member having both ends, One end portion of the linear member or plate-like member forms a part of the first curved portion, and the other end portion of the linear member or plate-like member forms the other part of the first curved portion. A fuel injection valve in which the tip of at least one of the aforementioned end portions or the other end portion is extended radially outward to form the extended portion.

Images