阅读说明：本技术 燃料喷射装置及燃料喷射阀 (Fuel injection device and fuel injection valve ) 是由 荒木健 于 2019-06-24 设计创作，主要内容包括：目的是提供能够抑制燃料喷射阀的进口连接器的松动的燃料喷射装置及燃料喷射阀。在具备将燃料加压并喷出的泵和将被加压的燃料喷射的燃料喷射阀的燃料喷射装置中,燃料喷射阀具备主体部和进口连接器,所述主体部具备燃料喷射孔及将燃料向燃料喷射孔引导的燃料通路,所述进口连接器被安装在主体部,形成有与燃料通路连通的燃料通过孔,且连接燃料配管；进口连接器与燃料配管借助单触式联接器被连接。(The purpose is to provide a fuel injection device and a fuel injection valve capable of suppressing looseness of an inlet connector of the fuel injection valve. In a fuel injection device including a pump for pressurizing and discharging fuel and a fuel injection valve for injecting the pressurized fuel, the fuel injection valve includes a main body portion including a fuel injection hole and a fuel passage for guiding the fuel to the fuel injection hole, and an inlet connector attached to the main body portion, having a fuel passage hole communicating with the fuel passage, and connected to a fuel pipe; the inlet connector and the fuel pipe are connected by a one-touch coupling.)

1. A fuel injection device (10) is provided with a pump (13) for pressurizing and discharging fuel and a fuel injection valve (50) for injecting the pressurized fuel,

the fuel injection valve (50) is provided with a main body part (51) and an inlet connector (40), the main body part (51) is provided with a fuel injection hole (63) and a fuel passage (90) for guiding fuel to the fuel injection hole (63), the inlet connector (40) is installed on the main body part (51), is provided with a fuel through hole (41) communicated with the fuel passage (90), and is connected with a fuel pipe (20);

the inlet connector (40) and the fuel pipe (20) are connected by a one-touch coupling (30).

2. The fuel injection apparatus (10) according to claim 1,

the aforementioned one-touch coupling (30) comprises a male coupling (31) and a female coupling (21), the male coupling (31) having a substantially cylindrical plug (33), the female coupling (21) having a substantially cylindrical socket (23) into which the plug (33) of the aforementioned male coupling (31) is inserted;

the female coupling (21) includes a lock member (25), and the lock member (25) is attached to be axially movable to a lock position and an unlock position on the outer periphery of the socket (23);

the lock device is provided with a regulation structure for regulating the axial movement of the lock member (25) from the lock position.

3. The fuel injection device (10) according to claim 1 or 2,

the aforementioned one-touch coupling (30) comprises a male coupling (31) and a female coupling (21), the male coupling (31) having a substantially cylindrical plug (33), the female coupling (21) having a substantially cylindrical socket (23) into which the plug (33) of the aforementioned male coupling (31) is inserted;

the plug connector is provided with a seal ring (26), and the seal ring (26) is arranged between the outer peripheral surface of the plug (33) and the inner peripheral surface of the socket (23).

4. A fuel injection valve (50) characterized in that,

the fuel injection device is provided with a main body part (51) and an inlet connector (40), wherein the main body part (51) is provided with a fuel injection hole (63) and a fuel passage (90) for guiding fuel to the fuel injection hole (63), and the inlet connector (40) is installed on the main body part (51) and is provided with a fuel through hole (41) communicated with the fuel passage (90);

the inlet connector (40) is provided with a connecting part (31) for connecting the fuel piping (20);

the connection part (31) is a male coupling (31) or a female coupling (21) constituting a one-touch coupling (30).

Technical Field

The present invention relates to a fuel injection device and a fuel injection valve.

Background

A common rail system is known as a system for injecting fuel into a combustion chamber of an internal combustion engine such as a diesel engine. The common rail system accumulates fuel pressurized by a fuel supply pump in a common rail to increase the pressure, and supplies the fuel increased to a predetermined pressure to a fuel injection valve.

A fuel injection valve used in a common rail system has a main body portion formed with a fuel injection hole. The main body portion is provided with a fuel passage for guiding fuel supplied from the common rail to the fuel injection hole. Further, the main body is connected to an inlet connector having a fuel passage hole communicating with the fuel passage and connecting a fuel pipe having the other end connected to the common rail.

For example, as disclosed in patent document 1, one axial end side of the inlet connector is configured as a male screw portion to be attached to a female screw portion formed in a main body portion of the fuel injection valve, and the other axial end side is configured as a male screw portion to be attached to a female screw portion formed in an end portion of the fuel pipe.

Disclosure of Invention

Problems to be solved by the invention

However, in the fuel injection valve disclosed in patent document 1, when the fuel pipe is detached from the inlet connector, there is a possibility that the screw of the inlet connector to the main body of the fuel injection valve becomes loose. Specifically, in the case of a structure in which the inlet connector is screwed to each of the fuel injection valve and the fuel pipe, the rotational directions of the respective connection portions are the same so that the inlet connector does not become loose when the fuel pipe is connected to the inlet connector screwed to the main body portion of the fuel injection valve. Therefore, when the fuel pipe is detached from the inlet connector, the inlet connector may be loosened from the body of the fuel injection valve.

If the rotational direction of tightening of the connection portions is opposite to each other, there is a possibility that the tightening of the inlet connector to the main body portion of the fuel injection valve may be loosened when the fuel pipe is connected to the inlet connector screwed to the main body portion of the fuel injection valve. If the inlet connector is loosened from the body portion, fuel may leak, and therefore the fuel injection valve must be replaced. In order to suppress such looseness, it is necessary to perform an operation of attaching and detaching the fuel pipe while holding the inlet connector by using a predetermined jig, which takes time.

In addition, in the case where a screw fixing structure is used as a structure for attaching the fuel pipe to the main body of the fuel injection valve via the inlet connector, the inlet connector may be loosened due to loosening of the screw, which may cause fuel leakage.

The present invention has been made in view of the above problems, and provides a fuel injection device and a fuel injection valve capable of suppressing the looseness of an inlet connector of the fuel injection valve.

Means for solving the problems

In order to solve the above problems, according to an aspect of the present invention, there is provided a fuel injection device including a pump for pressurizing and discharging fuel and a fuel injection valve for injecting the pressurized fuel, wherein the fuel injection valve includes a main body portion including a fuel injection hole and a fuel passage for guiding the fuel to the fuel injection hole, and an inlet connector attached to the main body portion, having a fuel passage hole communicating with the fuel passage, and connected to a fuel pipe; the inlet connector and the fuel pipe are connected by a one-touch coupling.

In order to solve the above problem, according to another aspect of the present invention, there is provided a fuel injection valve including a main body portion including a fuel injection hole and a fuel passage for guiding fuel to the fuel injection hole, and an inlet connector attached to the main body portion and having a fuel passage hole communicating with the fuel passage; the inlet connector is provided with a connecting part for connecting the fuel piping; the connection part is a male coupling or a female coupling constituting a one-touch coupling.

Effects of the invention

As described above, according to the present invention, looseness of the inlet connector of the fuel injection valve can be suppressed.

Drawings

Fig. 1 is a schematic diagram showing a common rail system as a fuel injection device according to an embodiment of the present invention.

Fig. 2 is a view showing an inlet connector and an end portion of a fuel pipe.

Fig. 3 is a sectional view of a portion constituting the one-touch coupling.

Fig. 4 is an explanatory diagram showing a locked state of the one-touch coupling.

Fig. 5 is an explanatory diagram showing an unlocked state of the one-touch coupling.

Fig. 6 is an explanatory diagram showing a locked state of the one-touch coupling according to the application example.

Fig. 7 is an explanatory diagram showing an unlocked state of the one-touch coupling according to the application example.

Fig. 8 is an explanatory diagram showing an unlocked state of the one-touch coupling according to the application example, as viewed from another direction.

Fig. 9 is an explanatory view showing example 1 in which a ball is held at a predetermined position of a groove.

Fig. 10 is an explanatory view showing example 2 in which a ball is held at a predetermined position of a groove.

Fig. 11 is an explanatory view showing example 3 in which a ball is held at a predetermined position of a groove.

Fig. 12 is an explanatory diagram showing another example of the fuel injection valve.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, the same reference numerals are given to the constituent elements having substantially the same functional configurations, and redundant description thereof is omitted. In the following embodiments, the end portion side where the fuel injection hole is formed is referred to as the lower side of the fuel injection valve, and the end portion side opposite to the end portion on the fuel injection hole side is referred to as the upper side of the fuel injection valve.

(basic Structure of Fuel injection device and Fuel injection valve)

Fig. 1 is a schematic diagram showing a common rail system as a fuel injection device according to the present embodiment. The common rail system 10 includes fuel injection valves 50, a common rail 15, and a fuel supply pump 13. The fuel supply pump 13 pressurizes the fuel and pressure-feeds the fuel to the common rail 15. The common rail 15 accumulates and boosts the fuel, and supplies the boosted fuel to the fuel injection valve 50. The fuel injection valve 50 injects fuel into a combustion chamber of an unillustrated internal combustion engine such as a diesel engine.

In the common rail system 10, the fuel supplied from the fuel tank 11 to the common rail 15 by the fuel supply pump 13 is accumulated in the common rail 15, is pressurized, and is supplied to the fuel injection valves 50 through the fuel pipes 20. In the common rail 15, for example, the same number of fuel injection valves 50 as the cylinders of the internal combustion engine are connected.

The main body 51 of the fuel injection valve 50 includes one or more fuel injection holes 63 formed at a lower end thereof. The main body 51 includes a fuel passage 90 for guiding fuel to the fuel injection hole 63. The main body 51 is provided with a fuel discharge passage 77 for discharging to the outside the excess fuel supplied from the common rail 15 to the main body 51.

The main body 51 of the fuel injection valve 50 according to the present embodiment includes a housing 53, a nozzle body 61, a nozzle nut 79, and a valve body 71. The housing 53 is formed with a through hole 55 penetrating in the vertical direction. The through hole 55 accommodates a valve piston 69 so as to be movable in the vertical direction.

The housing 53 is formed with a fuel passage 90 a. The lower end of the fuel passage 90a opens to the lower end surface of the housing 53, and the upper end opens to the side surface of the housing 53. An inlet connector 40 is connected to an upper end of the fuel passage 90a, and the inlet connector 40 is formed with a fuel passage hole 41 communicating with the fuel passage 90 a. The inlet connector 40 is connected to the fuel pipe 20 having the other end connected to the common rail 15.

A nozzle body 61 is attached to the lower end of the housing 53 using a nozzle nut 79. The nozzle body 61 is formed with a hole 65 opened at the upper end side. The hole 65 is disposed coaxially with the through hole 55 of the housing 53. The needle valve 67 is accommodated in the hole 65 so as to be movable in the vertical direction. The upper end of the needle valve 67 abuts against the lower end of the valve piston 69. The valve piston 69 and the needle valve 67 are always biased downward by the nozzle spring 68.

The vicinity of the lower end of the hole 65 becomes a seat portion 66 of the needle 67. Below the hole 65, a fuel injection hole 63 is formed that communicates the hole 65 with the outside of the nozzle body 61. A fuel reservoir 64 is formed in a part of the hole 65 at a position facing the pressure receiving portion 67a of the needle 67. One end of the fuel passage 90b communicates with the fuel reservoir 64. The other end of the fuel passage 90b communicates with the fuel passage 90a of the housing 53.

That is, in the fuel injection valve 50 according to the present embodiment, the fuel passage 90 that guides the fuel from the inlet connector 40 to the fuel injection port 63 is constituted by the fuel passage 90a of the housing 53, the fuel passage 90b of the nozzle body 61, the fuel reservoir 64, and the gap between the hole 65 and the needle 67.

The valve body 71 is inserted into the through hole 55 at the upper end of the housing 53. The valve body 71 has a hole 73 with an open lower end. The hole 73 is disposed coaxially with the through hole 55 of the housing 53. An upper portion of the valve piston 69 is inserted into the hole 73 to be slidable in the vertical direction. The area of the bore 73 above the top 69a of the valve piston 69 serves as a pressure control chamber 75.

The pressure control chamber 75 is supplied with fuel supplied from the common rail 15 via the fuel passage 93, the fuel reservoir chamber 57, and the fuel introduction orifice 72. The pressure in the pressure control chamber 75 is controlled by a solenoid valve 80. The seating and separation of the needle valve 67 with respect to the seat portion 66 of the nozzle body 61 can be controlled by controlling the pressure of the pressure control chamber 75 by the solenoid valve 80 and controlling the back pressure of the needle valve 67 via the valve piston 69.

In a state where the electromagnetic valve 80 is closed, the needle valve 67 is seated on the seat portion 66 of the nozzle body 61 by the back pressure of the pressure control chamber 75 and the urging force of the nozzle spring 68, closing the fuel injection hole 63. On the other hand, if the solenoid valve 80 is opened and the high pressure of the pressure control chamber 75 is opened to the low pressure side, the needle 67 is separated from the seat portion 66 against the urging force of the nozzle spring 68 by the high pressure acting on the pressure receiving portion 67a, and the fuel injection valve 50 is opened. The fuel opened to the low pressure side is returned to the fuel tank 11 via the fuel discharge passage 77.

(connection Structure of Fuel injection valve and Fuel piping)

Next, a connection structure between the fuel injection valve 50 and the fuel pipe 20 will be described.

As described above, the fuel injection valve 50 and the fuel pipe 20 are connected via the inlet connector 40. The inlet connector 40 is screwed to a housing 53 of the main body 51 of the fuel injection valve 50. Specifically, a male screw portion 43 is formed at one axial end side of the inlet connector 40. The male screw portion 43 is coupled to a female screw portion 59 formed in the housing 53.

The inlet connector 40 and the fuel line 20 are connected by the one-touch coupling 30. In the fuel injection valve 50 shown in fig. 1, the inlet connector 40 is provided with the male coupling 31 of the one-touch coupling 30, and the fuel pipe 20 is provided with the female coupling 21 of the one-touch coupling 30.

Fig. 2 and 3 are explanatory views showing the structures of the inlet connector 40 and the end portion of the fuel pipe 20. Fig. 2 is a view showing the inlet connector 40 and the end of the fuel pipe 20. Fig. 3 is a sectional view of a portion constituting the one-touch coupling 30.

On an end portion side of the inlet connector 40 opposite to the male screw portion 43 side, a male coupling 31 as a connection portion is provided. The male coupling 31 has a substantially cylindrical plug 33. The inlet connector 40 is formed with fuel passage holes 41 opening at both ends in the axial direction, and one end of the fuel passage hole 41 is formed in the axial center portion of the plug 33. A groove 35 is formed on the outer peripheral surface of the plug 33 over the entire periphery. A groove 38 is formed over the entire circumference on the outer circumferential surface of the distal end portion of the plug 33, and a seal ring 39 is disposed in the groove 38. The seal ring 39 elastically contacts the inner circumferential surface of the socket 23 of the female coupling 21 and the outer circumferential surface of the plug 33 of the male coupling 31 when the inlet connector 40 is coupled to the fuel pipe 20, and has a function of preventing fuel leakage.

A female coupling 21 is provided at an end of the fuel pipe 20. The female coupling 21 has a substantially cylindrical socket 23. The socket 23 serves as an opening end of the fuel pipe 20. The plug 33 of the male coupling 31 of the inlet connector 40 is inserted in the socket 23. A groove 24 is formed on the inner peripheral surface of the socket 23 over the entire periphery, and a seal ring 26 is disposed in the groove 24. The seal ring 26 elastically contacts the inner circumferential surface of the socket 23 of the female coupling 21 and the outer circumferential surface of the plug 33 of the male coupling 31 when the inlet connector 40 is coupled to the fuel pipe 20, and has a function of preventing damage to a connection portion due to intrusion of dust or the like.

The socket 23 has a plurality of holes 28, the plurality of holes 28 being provided to communicate the internal space with the outside, and balls 27 being arranged in the plurality of holes 28, respectively. Each hole 28 is formed so that the opening area becomes smaller toward the internal space side so that the ball 27 cannot enter the internal space side of the socket 23. An annular lock member 25 is attached to an outer peripheral portion of the receptacle 23. The lock member 25 is attached to be movable in the axial direction on the outer peripheral portion of the receptacle 23. The inner peripheral portion of the lock member 25 has a large diameter portion 25a and a small diameter portion 25 b. The large diameter portion 25a is formed on the opening end side of the socket 23.

As shown in fig. 4, in a state (locked position) in which the ball 27 of the socket 23 is located at the small diameter portion 25b of the inner peripheral portion of the lock member 25, the ball 27 is pushed into the inner space side of the socket 23. When the plug 33 of the male coupling 31 of the inlet connector 40 is inserted into the socket 23, the balls 27 enter the grooves 35 of the outer peripheral surface of the plug 33, and the male coupling 31 and the female coupling 21 are in a locked state.

As shown in fig. 5, in a state (unlock position) in which the ball 27 of the socket 23 is located at the large diameter portion 25a of the inner peripheral portion of the lock member 25, the ball 27 is movable in the outer direction of the socket 23. When the plug 33 of the male coupling 31 of the inlet connector 40 is inserted into the socket 23, the ball 27 can move out of the groove 35 of the plug 33, and the male coupling 31 and the female coupling 21 are in the unlocked state.

The balls 27 may also be surface treated for improved wear resistance. For example, the surface of the balls 27 may also be coated with DLC (Diamond-Like Carbon). This can reduce the possibility that the ball 27 is worn by pulsation of the high-pressure fuel or the like and the connection portion of the one-touch coupling 30 is damaged.

If the inlet connector 40 and the fuel pipe 20 are connected by the one-touch coupling 30, the assembly operation of the fuel pipe 20 to the inlet connector 40 is facilitated. Further, the work of removing the fuel pipe 20 from the inlet connector 40 is facilitated. In particular, when the fuel pipe 20 is removed from the inlet connector 40, the possibility of the inlet connector 40 screwed to the housing 53 becoming loose can be reduced without using a jig.

(application example)

Next, an application example of the connection structure between the fuel injection valve 50 and the fuel pipe 20 will be described.

Fig. 6 to 8 are explanatory views showing a connection structure according to an application example. Fig. 6 shows a state in which the lock member 25 of the female coupling 21 is in the lock position, and fig. 7 shows a state in which the lock member 25 of the female coupling 21 is in the unlock position. Fig. 8 shows a state of fig. 7 as viewed from below.

In the application example, a restriction structure that restricts the axial movement of the lock member 25 from the lock position is provided so that the engagement of the one-touch coupling 30 is not erroneously released or unintentionally released due to pulsation of high-pressure fuel or the like. Specifically, a pin 103 is provided upright on the outer peripheral surface of the socket 23 of the female coupling 21. Further, an L-shaped groove 101 is formed in the inner peripheral surface of the lock member 25 of the female coupling 21. The pin 103 can enter the groove 101.

When the one-touch coupling 30 is brought into the locked state, the lock member 25 is moved in the axial direction to insert the pin 103 along the axial portion 101b of the L-shaped groove 101, and then the lock member 25 is axially rotated to position the pin 103 at the circumferential portion 101a of the L-shaped groove 101. Thereby, the axial movement of the pin 103 is restricted, and the lock member 25 is in a state of being unable to move in the axial direction from the lock position. Thus, the engagement of the one-touch coupling 30 is not easily released. The groove 101 is not limited to an L-shaped groove.

In order to make the engagement of the one-touch coupling 30 difficult to be released, the ball 27 of the female coupling 21 may be held at a predetermined position of the groove 35 of the male coupling 31. Fig. 9 to 11 are explanatory views showing a configuration example of holding the ball 27 at a predetermined position of the concave groove 35.

Fig. 9 is a structure in which the movement of the ball 27 in the groove 35 is restricted by urging the ball 27 to the groove 35 side using the coil spring 105. Fig. 10 is a structure in which the ball 27 is positioned with respect to the groove 35a by narrowing the width of the groove 35 a. Fig. 11 shows a structure in which the ball 27 is positioned with respect to the groove 35b by forming the groove 35b into a V-shaped cross section.

By restricting the movement of the balls 27 relative to the grooves 35, the possibility of rattling between the male coupling 31 and the female coupling 21 due to pulsation of the high-pressure fuel can be reduced.

In the above-described embodiment, the seal ring 26 for preventing damage of the connection portion due to intrusion of dust or the like is disposed in the recessed groove 24 formed over the entire circumference on the inner circumferential surface of the socket 23 of the female coupling 21, but the seal ring may be disposed in a recessed groove formed on the outer circumferential surface of the plug 33 of the male coupling 31.

As described above, according to the common rail system 10 according to the present embodiment, the inlet connector 40 and the fuel pipe 20 are connected by the one-touch coupling 30. This facilitates the operation of attaching and detaching the fuel pipe 20 to and from the inlet connector 40. Further, when the fuel pipe 20 is attached to and detached from the inlet connector 40, the inlet connector 40 screwed to the housing 53 can be prevented from loosening.

Further, when the female coupling 21 of the one-touch coupling 30 has a restriction structure for restricting the axial movement of the lock member 25 from the lock position, it is possible to reduce the possibility that the coupling of the one-touch coupling 30 is erroneously released or unintentionally released due to pulsation of the high-pressure fuel or the like.

The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention belongs can conceive various modifications and alterations within the scope of the technical idea described in the claims, and it is understood that they also naturally belong to the technical scope of the present invention.

For example, in the above-described embodiment, the inlet connector 40 is screwed to the main body portion 51 (housing 53) of the fuel injection valve 50, but the present invention is not limited to this example. For example, as shown in fig. 12, the present invention can be applied to a fuel injection valve having the following structure: the inlet connector 125 is inserted into a hole 121a of an engine head 121, and a nut 127 is tightened against the engine head 121, whereby the tip end of the inlet connector 125 is liquid-tightly pressed against a contact surface 123a of a main body 123 of the fuel injection valve. In the fuel injection valve having such a configuration, the inlet connector 125 and the fuel pipe 111 are connected by the one-touch coupling 110, so that the loosening of the inlet connector 125 due to the loosening of the nut 127 is suppressed, and the fuel leakage can be prevented.

In the above embodiment, the inlet connector 40 is provided with the male coupling 31 and the fuel pipe 20 is provided with the female coupling 21, but the inlet connector 40 may be provided with the female coupling and the fuel pipe 20 may be provided with the male coupling.

Description of the reference numerals

10 ･ ･ ･ fuel injection device (common rail system); 13 ･ ･ ･ fuel supply pump; 15 ･ ･ ･ common rail; 20 ･ ･ ･ fuel piping; 21 ･ ･ ･ female coupling; 23 ･ ･ ･ socket (socket); 25 ･ ･ ･ locking member; 27 ･ ･ ･ ball; 30 ･ ･ ･ one-touch coupler (one touch coupler); 31 ･ ･ ･ male coupling; 33 ･ ･ ･ plug (plug); 35 ･ ･ ･ grooves; 38 ･ ･ ･ grooves; 39 ･ ･ ･ sealing ring; 40 ･ ･ ･ inlet connector (inlet connector); 43 ･ ･ ･ male threaded portion; 50 ･ ･ ･ fuel injection valve; 51 ･ ･ ･ a body portion; 63 ･ ･ ･ fuel injection holes; 90 ･ ･ ･ fuel path.