JP2018123826A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection valve capable of adjusting braking force acting on a valve body while suppressing an effect on magnetic force.SOLUTION: A fuel injection valve comprises: a movable structure which has a coil 70, a fixed core 50, a movable core 40 and a valve body 30; and a body which houses the movable structure therein so as to allow the movable structure to move. The movable structure has: a movable flow passage F20 formed therein; and an orifice 32a (narrowed section) which restricts a flow rate with a flow passage area of the movable flow passage F20 locally narrowed. The flow passage has: a narrowed flow passage F22 narrowed by the orifice 32a; and a sliding flow passage F27s (additional flow passage) which allows fuel to flow independently from the narrowed flow passage F22 and is formed between the movable structure and the body. The flow passage area of the sliding flow passage F27s is smaller than that of the narrowed flow passage F22. A position of a sliding face 33a in a vertical direction with respect to a sliding direction of the movable structure is different from an outermost peripheral position of the movable core 40.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fuel injection valve that injects fuel from an injection hole.

  In a conventional fuel injection valve, a movable core is moved by a magnetic force generated by energizing a coil, and an injection hole is opened and closed by a valve body attached to the movable core.

  The higher the valve opening speed of the valve body, the larger the inclination of the injection amount characteristic representing the relationship between the energization time to the coil and the injection amount. In particular, in order to shorten the energization time and minimize the injection amount, when performing partial lift injection that starts the valve closing operation before the valve element reaches the full lift position, the valve opening speed is the slope of the injection amount characteristic. The injection amount varies with respect to the energization time. Further, the faster the valve closing speed of the valve body, the easier it is for the valve body to bounce on the seating surface, and unintended injection occurs when the bounce occurs. For this reason, there exists a need of the technique which suppresses the valve opening speed and valve closing speed of a valve body appropriately.

  In response to the above bounce problem, Patent Document 1 discloses that a through-hole penetrating in the moving direction of the movable core is formed in the movable core, and an orifice is disposed in the through-hole. According to this, since the fuel flowing through the through hole is throttled by the orifice, a braking force acts on the movable core. Therefore, it is possible to suppress the braking force from acting on the valve body that performs the valve closing operation and the bounce of the valve body on the seating surface.

JP 2016-48066 A

  In the structure provided with the orifice as described above, the pressure area on the injection hole side (downstream area) and the pressure area on the counter-injection hole side (upstream area) are divided with respect to the boundary surface including the orifice and the sliding surface. When there is a flow through the orifice, there will be a pressure difference in both areas. In the following description, the surface on which the movable core receives fuel pressure from the upstream region is referred to as an upstream pressure receiving surface, and the surface that receives fuel pressure from the downstream region is referred to as an injection hole side pressure receiving surface.

  Depending on the difference between the value obtained by multiplying the area of the upstream pressure receiving surface by the pressure in the upstream region and the value obtained by multiplying the area of the downstream pressure receiving surface by the pressure in the downstream region, during opening / closing operation The braking force acting on the valve body is specified. Therefore, the brake force can be adjusted to a desired magnitude by adjusting the areas of the upstream pressure receiving surface and the downstream pressure receiving surface or adjusting the degree of restriction by the orifice.

  However, in the structure of the fuel injection valve described in Patent Document 1, the area is determined by the outer diameter of the movable core. Therefore, when the area is adjusted, the outer diameter of the movable core changes and acts on the movable core. The magnetic force to change greatly. Therefore, it is difficult to adjust the braking force by adjusting the area. Therefore, the only way to adjust the braking force is to change the degree of restriction of the orifice, and it is difficult to adjust the degree of restriction to simultaneously satisfy multiple characteristics such as pressure loss, braking force, and unintentional valve opening due to pulsation. It is.

  The present invention has been made in view of the above problems, and an object thereof is to provide a fuel injection valve capable of adjusting a braking force acting on a valve body while suppressing an influence on a magnetic force.

  The invention disclosed herein employs the following technical means to achieve the above object. Note that the reference numerals in parentheses described in the claims and in this section indicate the correspondence with the specific means described in the embodiments described later, and do not limit the technical scope of the invention. .

The first invention disclosed is
In a fuel injection valve having an injection hole (23a) for injecting fuel and a flow passage (F) for flowing fuel to the injection hole,
A coil (70) for generating magnetic flux when energized;
A fixed core (50) that creates a magnetic force by forming a path of magnetic flux;
A movable flow path (F20) that has a movable core (40) that moves by magnetic force and a valve body (30) that is driven by the movable core to open and close the nozzle hole is formed inside. Movable structures (M, M1, M2),
A body (B) in which the movable structure is housed in a movable state and a part of the flow path is formed inside;
With
The movable structure has a throttle part (32a) that partially narrows the passage area of the movable flow passage to restrict the flow rate,
The flow passage is a restriction flow passage (F22) which is a flow passage by the restriction portion, and a passage through which fuel flows independently of the restriction flow passage and is formed between the movable structure and the body (F27s). ), And
The passage area of the separate flow passage is smaller than the passage area of the throttle flow passage,
The position of the separate flow path in the direction perpendicular to the moving direction of the movable structure is a fuel injection valve different from the outermost peripheral position of the movable core.

  In the first aspect of the invention, the throttle flow passage and the separate flow passage are independent, and the passage area of the separate flow passage is smaller than the passage area of the narrow flow passage. For this reason, the flow passage is divided into an upstream region and a downstream region with the throttle portion as a boundary. The upstream region is a region on the upstream side of the fuel flow at the time of full lift injection with respect to the throttle portion, and the downstream region is a region on the downstream side of the fuel flow at the time of full lift injection with respect to the throttle portion. When the movable structure is moved, a pressure difference is generated in both regions due to the fuel flow rate being throttled in the throttle flow passage. In the following description, the surface on which the movable structure receives the fuel pressure from the upstream region to the valve closing side is referred to as the upstream pressure receiving surface, and the surface that receives the fuel pressure from the downstream region on the valve opening side is the downstream pressure receiving surface. Call it.

  Further, in the first aspect of the invention, there is provided a configuration in which “the position of the separate flow path in the direction perpendicular to the sliding direction of the movable structure is different from the outermost peripheral position of the movable core”. Therefore, the areas of the upstream pressure receiving surface and the downstream pressure receiving surface described above can be adjusted while suppressing the influence on the magnetic force. As described above, the braking force of the fuel applied to the moving movable structure is specified based on the area of the upstream pressure receiving surface, the area of the downstream pressure receiving surface, and the pressure difference between the two regions.

  Therefore, according to the said 1st invention, the area of an upstream pressure receiving surface and the area of a downstream pressure receiving surface can be adjusted, suppressing the influence on a magnetic force by adjusting the position of a separate flow path. Therefore, the brake force can be adjusted while suppressing a change in magnetic force acting on the movable core.

The second invention disclosed is
In a fuel injection valve having an injection hole (23a) for injecting fuel and a flow passage (F) for flowing fuel to the injection hole,
A coil (70) for generating magnetic flux when energized;
A fixed core (50) that creates a magnetic force by forming a path of magnetic flux;
A movable flow path (F20) that has a movable core (40) that moves by magnetic force and a valve body (30) that is driven by the movable core to open and close the nozzle hole is formed inside. Movable structures (M, M1, M2),
A body (B) in which the movable structure is housed in a movable state and a part of the flow path is formed inside;
With
The movable structure has a throttle part (32a) that partially narrows the passage area of the movable flow passage to restrict the flow rate, and a sliding surface (33a) with the body,
The flow path includes a throttle flow path (F22) that is a flow path by the throttle unit,
The position of the sliding surface in the direction perpendicular to the sliding direction of the movable structure is a fuel injection valve different from the outermost peripheral position of the movable core.

  According to the second aspect of the invention, the flow path is divided into an upstream region and a downstream region with the throttle portion as a boundary. The upstream region is a region on the upstream side of the fuel flow at the time of full lift injection with respect to the throttle portion, and the downstream region is a region on the downstream side of the fuel flow at the time of full lift injection with respect to the throttle portion. When the movable structure is moved, a pressure difference is generated in both regions due to the fuel flow rate being throttled in the throttle flow passage. In the following description, the surface on which the movable structure receives the fuel pressure from the upstream region to the valve closing side is referred to as the upstream pressure receiving surface, and the surface that receives the fuel pressure from the downstream region on the valve opening side is the downstream pressure receiving surface. Call it.

  Furthermore, in the second aspect of the invention, the configuration is such that “the position of the separate flow path in the direction perpendicular to the sliding direction of the movable structure is different from the outermost peripheral position of the movable core”. Therefore, the areas of the upstream pressure receiving surface and the downstream pressure receiving surface described above can be adjusted while suppressing the influence on the magnetic force. As described above, the braking force of the fuel applied to the moving movable structure is specified based on the area of the upstream pressure receiving surface, the area of the downstream pressure receiving surface, and the pressure difference between the two regions.

  Therefore, according to the second aspect, by adjusting the position of the sliding surface, the area of the upstream pressure receiving surface and the area of the downstream pressure receiving surface can be adjusted while suppressing the influence on the magnetic force. Therefore, the brake force can be adjusted while suppressing a change in magnetic force acting on the movable core.

Sectional drawing of the fuel injection valve which concerns on 1st Embodiment of this invention. Sectional drawing which expanded FIG. Sectional drawing of the movable structure M which concerns on 1st Embodiment. It is sectional drawing of the fuel injection valve which concerns on 2nd Embodiment of this invention, Comprising: Sectional drawing which shows the state in which the moving member was seated on the fixed member. It is sectional drawing of the fuel injection valve which concerns on 2nd Embodiment, Comprising: Sectional drawing which shows the state which the moving member separated from the fixed member. Sectional drawing of the fuel injection valve which concerns on 3rd Embodiment of this invention. Sectional drawing of the fuel injection valve which concerns on 4th Embodiment of this invention. Sectional drawing of the fuel injection valve which concerns on 5th Embodiment of this invention.

  Hereinafter, a plurality of modes for carrying out the invention will be described with reference to the drawings. In each embodiment, portions corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals and redundant description may be omitted. In each embodiment, when only a part of the configuration is described, the other configurations described above can be applied to other portions of the configuration.

(First embodiment)
The fuel injection valve shown in FIG. 1 is mounted on an ignition internal combustion engine (gasoline engine), and directly injects fuel into each combustion chamber of a multi-cylinder engine. The fuel supplied to the fuel injection valve is pumped by a fuel pump (not shown), and the fuel pump is driven by the rotational driving force of the engine. The fuel injection valve includes a case 10, a nozzle body 20, a valve body 30, a movable core 40, a fixed core 50, a nonmagnetic member 60, a coil 70, a pipe connection portion 80, and the like.

  The case 10 is made of metal and has a cylindrical shape extending in a direction in which the annular center line C of the coil 70 extends (hereinafter referred to as an axial direction). The annular center line C of the coil 70 coincides with the center axes of the case 10, the nozzle body 20, the valve body 30, the movable core 40, the fixed core 50, and the nonmagnetic member 60.

  The nozzle body 20 is made of metal, and has a main body portion 21 that is inserted into the case 10 and engages with the case 10, and a nozzle portion 22 that extends from the main body portion 21 to the outside of the case 10. The nozzle portion 22 has a cylindrical shape extending in the axial direction, and an injection hole member 23 is attached to the tip of the nozzle portion 22.

  The nozzle hole member 23 is made of metal and is fixed to the nozzle portion 22 by welding. The injection hole member 23 has a bottomed cylindrical shape extending in the axial direction, and an injection hole 23 a for injecting fuel is formed at the tip of the injection hole member 23. A seating surface 23 s on which the valve body 30 is seated is formed on the inner peripheral surface of the injection hole member 23.

  The valve body 30 is made of metal and has a cylindrical shape extending along the axial direction. The valve body 30 is assembled in the nozzle body 20 so as to be movable in the axial direction, and an annular flow extending in the axial direction between the outer peripheral surface 30a of the valve body 30 and the inner peripheral surface 22a of the nozzle body 20. A path (downstream path F30) is formed. An annular seat surface 30s is formed at the end of the valve body 30 on the nozzle hole 23a side so as to be separated from and seated on the seating surface 23s.

  A connecting member 31 is fixedly attached to the end of the valve body 30 opposite to the injection hole 23a (hereinafter referred to as the anti-injection hole side) by welding or the like. Furthermore, an orifice member 32 having an orifice 32a (throttle portion) and a movable core 40 are attached to the end of the connecting member 31 on the side opposite to the injection hole.

  As shown in FIG. 2, the connecting member 31 has a cylindrical shape extending in the axial direction, the orifice member 32 is fixed to the inner circumferential surface of the connecting member 31 by welding or the like, and the movable core 40 is a cylinder of the connecting member 31. It is fixed to the outer peripheral surface by welding or the like. A diameter-enlarged portion 31 a that expands in the radial direction is formed at the end of the connecting member 31 opposite to the injection hole. The end surface on the injection hole side of the enlarged diameter portion 31 a is engaged with the movable core 40, thereby preventing the connecting member 31 from coming out toward the injection hole with respect to the movable core 40.

  The orifice member 32 has a cylindrical shape extending in the axial direction, and the inside of the cylinder functions as a flow passage F21 through which fuel flows. At the nozzle hole side end of the orifice member 32, an orifice 32a (throttle portion) for narrowing the flow area by partially narrowing the passage area of the flow passage F21 is formed. A portion of the flow passage F21 that is restricted by the orifice 32a is referred to as a restriction flow passage F22.

  The throttle flow path F <b> 22 is located on the central axis of the valve body 30. The flow path length of the throttle flow path F22 is shorter than the diameter of the throttle flow path F22. A diameter-enlarged portion 32 b that expands in the radial direction is formed at the end of the orifice member 32 opposite to the injection hole. Since the end surface on the injection hole side of the enlarged diameter portion 32 b engages with the connecting member 31, the orifice member 32 is prevented from slipping out toward the injection hole with respect to the connecting member 31.

  The movable core 40 has a metal disk shape, and is accommodated in the cylinder of the main body 21. The movable core 40 moves in the axial direction integrally with the connecting member 31, the valve body 30, the orifice member 32, and the sliding member 33 described below. The movable core 40, the connecting member 31, the valve body 30, the orifice member 32, and the sliding member 33 correspond to a movable structure M that moves integrally in the axial direction.

  The sliding member 33 is separate from the movable core 40 and is pressed against the movable core 40 by the elastic force of the contact elastic member SP2. Thus, by making the sliding member 33 separate from the movable core 40, it is possible to easily realize that the material of the sliding member 33 is different from the material of the movable core 40. The movable core 40 is made of a highly magnetic material compared to the sliding member 33, and the sliding member 33 is made of a material having higher wear resistance than the movable core 40.

  The sliding member 33 has a cylindrical shape, and the cylindrical outer peripheral surface of the sliding member 33 functions as a sliding surface 33 a that slides with respect to the inner peripheral surface of the main body 21. The outer diameter dimension of the sliding surface 33 a is smaller than the outer diameter dimension of the movable core 40. That is, the position of the sliding surface 33 a in the direction perpendicular to the sliding direction of the sliding member 33 is located on the inner side of the outermost peripheral position of the movable core 40, that is, on the annular center line C side.

  The surface of the sliding member 33 on the side opposite to the injection hole functions as a sealing surface 33b that is in close contact with the surface of the movable core 40 on the injection hole side and seals the fuel from passing therethrough. Inside the cylinder of the sliding member 33, a coil-shaped elastic member SP2 for contact is disposed. The contact elastic member SP2 is elastically deformed in the axial direction to apply an elastic force to the sliding member 33, and the sealing surface 33b of the sliding member 33 is pressed against the surface of the movable core 40 on the side opposite to the injection hole with the elastic force. Be in close contact.

  A diameter-reduced portion 33 c that decreases in the radial direction is formed at the end of the sliding member 33 on the side opposite to the injection hole. The upper surface of the reduced diameter portion 33c functions as a part of the seal surface 33b, and the lower surface of the reduced diameter portion 33c supports one end of the contact elastic member SP2. A support member 24 is fixed to the bottom surface of the main body 21, and the support member 24 is formed with a reduced diameter portion 24 a that decreases in the radial direction. The other end of the contact elastic member SP2 is supported by the reduced diameter portion 24a.

  The sliding member 33 is in a state in which it can move relative to the movable core 40 in the radial direction. A portion of the movable structure M excluding the sliding member 33 is provided with a guide portion that supports the nozzle body 20 in the radial direction while sliding the movable structure M so as to be movable in the axial direction. The guide portions are provided at two locations in the axial direction, and the guide portion located on the injection hole 23a side in the axial direction is referred to as the injection hole side guide portion 30b, and the guide portion located on the counter injection hole side is opposite. This is referred to as a nozzle hole side guide portion 31b (see FIGS. 1 and 2). The injection hole side guide portion 30 b is formed on the outer peripheral surface of the valve body 30 and is slidably supported on the inner peripheral surface of the injection hole member 23. The anti-injection hole side guide portion 31 b is formed on the outer peripheral surface of the connecting member 31 and is slidably supported on the inner peripheral surface of the support member 24.

  The fixed core 50 is fixedly disposed inside the case 10. The fixed core 50 is made of an annular metal extending around the axial direction. The nonmagnetic member 60 is an annular material disposed between the fixed core 50 and the main body 21, and is made of a material that is weaker than the fixed core 50 and the movable core 40. On the other hand, the fixed core 50, the movable core 40, and the main body 21 are made of a magnetic material.

  A cylindrical and metal stopper 51 is fixed to the inner peripheral surface of the fixed core 50. The stopper 51 restricts the connecting member 31 from moving toward the anti-injection hole side by contacting the connecting member 31. In a state where the upper end surface of the enlarged diameter portion 31 a of the connecting member 31 is in contact with the lower end surface of the stopper 51, the lower end surface of the fixed core 50 does not contact the upper end surface of the movable core 40, and between these lower end surface and the upper end surface. Thus, a predetermined gap is formed.

  A coil 70 is disposed on the radially outer side of the nonmagnetic member 60 and the fixed core 50. The coil 70 is wound around a resin bobbin 71. The bobbin 71 has a cylindrical shape centering on the axial direction. Therefore, the coil 70 is disposed in an annular shape extending around the axial direction.

  On the side of the fixed core 50 opposite to the injection hole, there is disposed a pipe connection portion 80 that forms a fuel inlet 80a and is connected to an external pipe. The pipe connection portion 80 is made of metal and is formed of a metal member integrated with the fixed core 50. The fuel pressurized by the high pressure pump is supplied to the fuel injection valve from the inflow port 80a. A fuel flow passage F11 extending in the axial direction is formed inside the pipe connection portion 80, and a press-fitting member 81 is press-fitted and fixed in the flow passage F11.

  An elastic member SP1 is disposed on the injection hole side of the press-fitting member 81. One end of the elastic member SP1 is supported by the press-fitting member 81, and the other end of the elastic member SP1 is supported by the enlarged diameter portion 32b of the orifice member 32. Therefore, the elastic deformation of the elastic member SP1 when the valve body 30 opens to the full lift position, that is, when the connecting member 31 contacts the stopper 51, according to the press-fitting amount of the press-fitting member 81, that is, the fixed position in the axial direction. The amount is specified. That is, the valve closing force (set load) by the elastic member SP1 is adjusted by the press-fitting amount of the press-fitting member 81.

  A fastening member 83 is disposed on the outer peripheral surface of the pipe connection portion 80. The fastening member 83 is fastened to the case 10 by fastening the screw portion formed on the outer peripheral surface of the fastening member 83 to the screw portion formed on the inner peripheral surface of the case 10. Due to the axial force generated by the fastening, the pipe connection portion 80, the fixed core 50, the nonmagnetic member 60, and the main body portion 21 are sandwiched between the bottom surface of the case 10 and the fastening member 83.

  The pipe connection part 80, the fixed core 50, the nonmagnetic member 60, the nozzle body 20, and the injection hole member 23 correspond to a body B having a flow passage F through which the fuel supplied to the inflow port 80a flows to the injection hole 23a. . It can be said that the movable structure M described above is accommodated in the body B in a slidable state.

  Next, the operation of the fuel injection valve will be described.

  When the coil 70 is energized, a magnetic field is generated around the coil 70. That is, a magnetic field circuit through which magnetic flux passes through the fixed core 50, the movable core 40, and the main body portion 21 is formed with energization, and the movable core 40 is attracted to the fixed core 50 by the magnetic force generated by the magnetic circuit. On the movable structure M, the valve closing force by the elastic member SP1, the valve closing force by the fuel pressure, and the valve opening force by the magnetic force described above act. Since the valve opening force is set to be greater than the valve closing force, the movable core 40 moves toward the fixed core 50 together with the valve body 30 when a magnetic force is generated with energization. . As a result, the valve body 30 is opened to seat the seat surface 30s away from the seating surface 23s, and the high-pressure fuel is injected from the injection hole 23a.

  When the energization of the coil 70 is stopped, the valve opening force due to the magnetic force described above is lost, so that the valve element 30 is closed together with the movable core 40 by the valve closing force of the elastic member SP1, and the seat surface 30s is seated. Sitting on the surface 23s. As a result, the valve body 30 is closed, and fuel injection from the injection hole 23a is stopped.

  Next, the flow of fuel when fuel is being injected from the injection hole 23a will be described.

  The high-pressure fuel supplied from the high-pressure pump to the fuel injection valve flows in from the inflow port 80a and flows along the cylindrical inner peripheral surface of the pipe connection portion 80, the flow passage F12 along the cylindrical inner peripheral surface of the press-fit member 81, It flows sequentially through the flow path F13 in which the elastic member SP1 is accommodated (see FIG. 1). These flow passages F11, F12, and F13 are collectively referred to as an upstream passage F10. The upstream passage F10 is located outside and on the upstream side of the movable structure M in the entire flow passage F existing inside the fuel injection valve. To position. Further, in the entire flow path F, a flow path formed by the movable structure M is referred to as a movable flow path F20, and a flow path positioned on the downstream side of the movable flow path F20 is referred to as a downstream path F30.

  The movable flow path F20 flows by dividing the fuel flowing out from the flow path F13 into a main path and a sub path described below. The main passage and the sub passage are arranged independently. Specifically, the main passage and the sub passage are arranged in parallel, and the fuel that has branched and flowed into each of them merges in the downstream passage F30.

  The main passage is a passage through which fuel flows in the order of a flow passage F21 along the cylindrical inner peripheral surface of the orifice member 32, a throttle flow passage F22 by the orifice 32a, and a flow passage F23 along the cylindrical inner peripheral surface of the connecting member 31. And the fuel of the flow path F23 flows into the downstream path F30 which is the flow path F31 along the cylindrical outer peripheral surface of the connection member 31 through the through-hole penetrating the connection member 31 in the radial direction.

  The sub-passage includes a flow passage F24s along the cylindrical outer peripheral surface of the orifice member 32, a flow passage F25s that is a gap between the movable core 40 and the fixed core 50, a flow passage F26s along the outer peripheral surface 40a of the movable core 40, and a sliding surface 33a. Is a passage through which fuel flows in the order of the flow passages along the line. The flow passage along the sliding surface 33 a is called a sliding flow passage F 27 s or a separate flow passage, and the fuel in the sliding flow passage F 27 s is a downstream passage F 30 that is a flow passage F 31 along the cylindrical outer peripheral surface of the connecting member 31. Flow into. The passage area of the flow passage F26s formed between the outermost periphery of the movable core 40 and the main body 21 is larger than the passage area of the sliding flow passage F27s. That is, the degree of restriction in the sliding flow path F27s is set larger than the degree of restriction in the flow path F26s.

  Here, the upstream side of the sub passage is connected to the upstream side of the throttle flow passage F22. Specifically, the portion of the sliding flow passage F27s (separate flow passage) on the side opposite to the injection hole is connected to the flow passage on the side opposite to the injection hole of the throttle flow passage F22. The downstream side of the sub flow path is connected to the downstream side of the throttle flow path F22. Specifically, the portion on the injection hole side of the sliding flow passage F27s (separate flow passage) is connected to the flow passage on the injection hole side of the throttle flow passage F22. That is, the sub-flow path connects the upstream side and the downstream side of the throttle flow path F22 without passing through the throttle flow path F22. Further, the sliding flow passage F27s (separate flow passage) is provided closer to the injection hole than the movable core 40.

  Further, the upstream side of the flow passage F23 is connected to the upstream side of the throttle flow passage F22. The downstream side of the flow passage F23 is connected to the downstream side of the throttle flow passage F22. That is, the flow path F23 connects the upstream side and the downstream side of the throttle flow path F22 without passing through the throttle flow path F22.

  In short, the fuel that has flowed into the movable flow path F20 from the flow path F13 that is the upstream path F10 branches into a flow path F21 that is the upstream end of the main path and a flow path F24s that is the upstream end of the sub-passage, It merges in the flow path F31 which is the downstream path F30.

  Each of the movable core 40, the connecting member 31, and the orifice member 32 is formed with a through hole 41 that penetrates in the radial direction. These through holes 41 function as a flow passage F28s that connects the flow passage F21 along the inner peripheral surface of the orifice member 32 and the flow passage F26s along the outer peripheral surface of the movable core 40. The flow passage F28s is configured to control the flow rate of fuel flowing through the sliding flow passage F27s, that is, the flow rate of the sub-passage when the connection member 31 comes into contact with the stopper 51 and the communication between the flow passage F24s and the flow passage F25s is blocked. It is a passage for securing. Since the flow passage F28s is positioned on the upstream side of the flow passage F22, the flow passages F25s, F26s, and F28s become upstream regions, which will be described later, and a pressure difference from the downstream region is generated.

  The fuel flowing out of the movable flow path F20 flows into the flow path F31 along the cylindrical outer peripheral surface of the connecting member 31, and then the flow path F32, which is a through hole penetrating the reduced diameter portion 24a of the support member 24 in the axial direction. It flows through the flow path F33 along the outer peripheral surface of the valve body 30 in order (see FIG. 2). When the valve body 30 is opened as described below, the high-pressure fuel in the flow passage F33 passes between the seat surface 30s and the seating surface 23s and is injected from the injection hole 23a.

  The flow path along the sliding surface 33a described above is called a sliding flow path F27s, and the passage area of the sliding flow path F27s is smaller than the passage area of the throttle flow path F22. That is, the degree of restriction in the sliding flow path F27s is set to be larger than the degree of restriction in the restriction flow path F22. The main passage has the smallest passage area of the throttle flow passage F22, and the sub passage has the smallest passage area in the sliding flow passage F27s.

  Therefore, the main passage is easier to flow between the main passage and the sub passage in the movable flow passage F20, and the restriction degree of the main passage is specified by the restriction degree of the orifice 32a, and the flow rate of the main passage is determined by the orifice 32a. It is adjusted by. In other words, the degree of restriction of the movable flow path F20 is specified by the degree of restriction at the orifice 32a, and the flow rate of the movable flow path F20 is adjusted by the orifice 32a.

  The passage area in the seat surface 30s of the flow passage F, and the passage area in the full lift state in which the valve body 30 has moved most in the valve opening direction is referred to as a seat passage area. The passage area of the throttle flow passage F22 by the orifice 32a is set larger than the sheet passage area. That is, the degree of restriction by the orifice 32a is set smaller than the degree of restriction on the seat surface 30s during full lift.

  The seat passage area is set larger than the passage area of the nozzle hole 23a. That is, the degree of restriction by the orifice 32a and the degree of restriction at the sheet surface 30s are set to be smaller than the degree of restriction at the nozzle hole 23a. When a plurality of nozzle holes 23a are formed, the seat passage area is set larger than the total passage area of all the nozzle holes 23a.

  Next, the braking force that the movable structure M receives from the fuel when the movable structure M moves will be described.

  In this embodiment, the throttle flow passage F22 and the sliding flow passage F27s are arranged in parallel, and the passage area of the sliding flow passage F27s is set smaller than the passage area of the throttle flow passage F22. Therefore, the flow passage F is divided into an upstream region and a downstream region with the orifice 32a (throttle portion) and the sliding flow passage F27s as a boundary.

  The upstream region is a region on the upstream side of the fuel flow at the time of injection with respect to the orifice 32a. Note that the upstream side of the sliding surface 33a in the movable flow path F20 also belongs to the upstream region. Therefore, the flow passages F21, F24s, F25s, F26s, F28s and the upstream passage F10 in the movable flow passage F20 correspond to the upstream region. The downstream region is a region on the downstream side of the fuel flow at the time of injection with respect to the orifice 32a. Note that the downstream side of the sliding surface 33a in the movable flow path F20 also belongs to the downstream region. Therefore, the flow passage F23 and the downstream passage F30 in the movable flow passage F20 correspond to the downstream region.

  In short, when the fuel flows through the throttle flow passage F22, the flow rate of the fuel flowing through the movable flow passage F20 is throttled by the orifice 32a, so that the fuel pressure in the upstream region (that is, the upstream fuel pressure PH) and the downstream region are reduced. A pressure difference with the fuel pressure (that is, the downstream fuel pressure PL) occurs. Accordingly, when the valve body 30 is changing from the closed state to the open state, when the valve body 30 is changing from the open state to the closed state, and when the valve body 30 is held at the full lift position, the throttle flow is reduced. The fuel flows in the path F22 and the pressure difference is generated.

  And the said pressure difference produced by valve opening of the valve body 30 does not disappear simultaneously with switching from valve opening to valve closing, but when the predetermined time passes after valve closing, the upstream fuel pressure PH and the downstream fuel pressure PL are the same. become. On the other hand, when switching from valve closing to valve opening in a state where the pressure difference does not occur, the pressure difference immediately occurs at the switching timing.

  As shown in FIG. 3, when the movable structure M moves, the surface of the movable structure M that receives the upstream fuel pressure PH on the valve closing side is called the upstream pressure receiving surface SH, and the downstream fuel pressure PL is set on the valve opening side. The receiving surface is referred to as a downstream pressure receiving surface SL.

  The apparent upstream pressure receiving surface SH1 is the upper end surface of the movable core 40, the connecting member 31, and the orifice member 32, and corresponds to the surface of the portion exposed in the upstream region. However, since the sliding surface 33a serving as the boundary between the two regions is located radially inside the outer peripheral surface 40a of the movable core 40, the pressure receiving surface located outside the sliding surface 33a of the lower end surface of the movable core 40. SH2 receives the upstream fuel pressure PH in the valve opening direction. Therefore, it can be said that the area obtained by subtracting the area of the pressure receiving surface SH2 that receives the fuel pressure in the valve opening direction from the apparent area of the upstream pressure receiving surface SH1 is the substantial area of the upstream pressure receiving surface SH.

  The downstream pressure receiving surface SL is the lower end surface of the sliding member 33, the connecting member 31, and the orifice member 32, and corresponds to the surface of the portion exposed in the downstream region. The area of the downstream pressure receiving surface SL is the same as that of the upstream pressure receiving surface SH.

  The value obtained by multiplying the upstream pressure receiving surface SH by the upstream fuel pressure PH corresponds to a force acting on the movable structure M on the valve closing side, and the value obtained by multiplying the downstream pressure receiving surface SL by the downstream fuel pressure PL is the movable structure. This corresponds to the force acting on the valve opening side with respect to the body M. A difference between these forces acts as a braking force on the movable structure M that moves.

  During the movement of the movable structure M in the valve opening direction, the fuel in the upstream region is pushed and compressed by the movable structure M, so the upstream fuel pressure PH increases. On the other hand, the fuel in the upstream region pushed by the movable structure M is pushed out to the downstream region while being throttled by the orifice 32a, so the downstream fuel pressure PL is lower than the upstream fuel pressure PH. Therefore, the braking force due to the pressure difference ΔP in both regions acts in a direction in which the movable structure M that moves in the valve opening direction is pushed back in the valve closing direction. In short, when the valve is opened, the fuel flows through the throttle flow passage F22 toward the nozzle hole, and the force obtained by multiplying the pressure difference ΔP generated by the throttle by the area S of the upstream pressure receiving surface SH or the downstream pressure receiving surface SL is It acts on the movable structure M as a braking force.

  While the movable structure M moves in the valve closing direction, the fuel in the downstream region is pushed and compressed by the movable structure M, so the downstream fuel pressure PL rises. On the other hand, since the fuel in the downstream region pushed by the movable structure M is pushed out to the upstream region while being throttled by the orifice 32a, the upstream fuel pressure PH becomes lower than the downstream fuel pressure PL. Therefore, the braking force due to the pressure difference ΔP in both regions acts in a direction in which the movable structure M that moves in the valve closing direction is pushed back in the valve opening direction. In short, when the valve is closed, fuel flows through the throttle flow passage F22 toward the counter-injection hole, and a force obtained by multiplying the pressure difference ΔP generated by the throttle at that time by the area S acts on the movable structure M as a braking force.

  Therefore, the braking force can be adjusted by adjusting at least one of the degree of restriction by the orifice 32a and the area S. The size of the area S can be adjusted by adjusting the diameter of the sliding surface 33a.

  Next, the operation and effect of the configuration adopted by the present embodiment will be described.

  According to the present embodiment, the throttle flow passage F22 and the sliding flow passage F27s are arranged in parallel, and the passage area of the sliding flow passage F27s is set smaller than the passage area of the throttle flow passage F22. Therefore, the flow path F is divided into an upstream region and a downstream region with the orifice 32a (throttle portion) as a boundary. When the movable structure M moves, a pressure difference ΔP is generated in both regions due to the fuel flow rate being reduced in the throttle flow passage F22, and the braking force is reduced due to the pressure difference ΔP. It acts on the movable structure M.

  Therefore, since the braking force acts on the movable structure M that performs the valve closing operation, it is possible to suppress the bounce of the valve body 30 on the seating surface 23s, and it is possible to reduce the possibility of an unintended injection state. Further, since the braking force acts on the movable structure M that opens the valve, the impact when the connecting member 31 collides with the stopper 51 can be reduced, and the wear of the connecting member 31 and the stopper 51 can be suppressed.

  In addition, in the present embodiment, the position of the sliding surface 33a in the direction perpendicular to the sliding direction of the movable structure M (that is, the radial direction) is different from the outermost peripheral position of the movable core 40. Therefore, the area S of the upstream pressure receiving surface SH and the downstream pressure receiving surface SL can be adjusted without changing the outermost peripheral position of the movable core 40. Therefore, the area S can be adjusted without changing the outermost peripheral position of the movable core 40 by adjusting the position of the sliding surface 33a. Therefore, the braking force can be adjusted without causing a large change in the magnetic force acting on the movable core 40.

  Further, in the present embodiment, the movable core 40 is formed with a through hole 41 that communicates the upstream portion of the throttle flow passage F22 and the upstream portion of the sliding flow passage F27s. Therefore, even if the orifice member 32 abuts on the stopper 51 and the communication between the flow passage F24s and the flow passage F25s is blocked, the pressure receiving surface SH2 that receives the upstream fuel pressure PH in the valve opening direction through the through hole 41. Fuel can be sent. Therefore, the certainty of making the area of the substantial upstream pressure receiving surface SH a desired size can be improved.

  Furthermore, in this embodiment, the material of the sliding member 33 that forms the sliding surface 33 a is different from the material of the movable core 40. Therefore, the sliding surface 33a can be made of a material with high durability priority, and the movable core 40 can be made of a material with low magnetic resistance priority.

  Furthermore, in this embodiment, the throttle flow path F22 is located on the central axis of the valve body 30. According to this, even if the position of the orifice 32a (throttle portion) in the direction perpendicular to the central axis (that is, the radial direction) is deviated from the desired position, the fluid resistance received by the orifice 32a is the central axis. Acts at a position close to. On the other hand, contrary to the present embodiment, when a plurality of throttle flow passages are arranged at positions away from the central axis, the fluid resistance is inclined to the movable structure M due to the positional deviation of the throttle flow passages. Acts as a force. Therefore, according to the present embodiment in which the throttle flow passage F22 is positioned on the central axis of the valve body 30, the tilting force acting on the movable structure M can be reduced.

  Furthermore, in this embodiment, the elastic member SP2 for contact | adhesion which presses the sliding member 33 which forms the sliding surface 33a against the movable core 40, and is stuck is provided. According to this, since the space between the movable core 40 can be sealed without fixing the sliding member 33 to the movable core 40, the sliding member 33 can be moved relative to the movable core 40 in the radial direction. The flow path F can be divided into an upstream region and a downstream region. If the sliding member 33 is fixed to the movable core 40 contrary to the present embodiment, it is required that the axial center of the sliding member 33 and the axial center of the movable core 40 be matched with high accuracy. However, according to the present embodiment, since the fixing can be made unnecessary, the dimensional accuracy required for the movable structure M can be relaxed.

  Furthermore, in this embodiment, the valve body 30 is fixed to the movable core 40 in a state in which relative movement is impossible. Here, contrary to the present embodiment, if the valve body is assembled to the movable core in a state where it can move relative to the movable core 40, the following concerns arise. That is, since the movable core moves relative to the valve immediately after the valve is closed, it is difficult for bounce to occur.However, the next injection cannot be started until the relatively moving movable core comes to a standstill, which impedes the implementation of injection in a short interval. Is concerned.

  On the other hand, in this embodiment, since the valve body 30 is fixed to the movable core 40 in a state in which the relative movement is impossible, it is possible to avoid the short interval from being hindered by waiting until the relative movement of the movable core stops. Nevertheless, since the above-described effect that the braking force can be adjusted by making the position of the sliding surface 33a in the radial direction different from the outermost peripheral position of the movable core 40, the bounce of the valve body 30 can be suppressed. That is, it is possible to achieve both shortening of the interval and suppression of bounce.

  Furthermore, in the present embodiment, the outermost diameter dimension of the sliding surface 33 a is smaller than the outermost diameter dimension of the movable core 40. That is, the sliding flow passage F27s is provided on the inner side of the outermost peripheral position of the movable core 40. In recent years, the pressure of fuel supplied to the fuel injection valve tends to increase, and along with this, the oil pressure acting on the valve body 30 increases, and as a result, the magnetic attractive force required to open the valve tends to increase. Therefore, the outermost diameter dimension of the movable core 40 tends to increase. Therefore, when the outermost diameter position of the movable core 40 is made to function as a sliding surface contrary to the present embodiment, there is a concern that the area of the downstream pressure receiving surface SL becomes larger than necessary and the braking force becomes larger than necessary. Is done. In contrast, in the present embodiment, the sliding surface 33a is provided at a position different from the outermost diameter position of the movable core 40, and the outermost diameter dimension of the sliding surface 33a is made smaller than the outermost diameter dimension of the movable core 40. Therefore, the above concerns can be suppressed.

(Second Embodiment)
The movable structure M1 of the fuel injection valve according to the present embodiment has a variable throttle mechanism that changes the throttle degree of the flow rate in the flow passage F. The variable throttle mechanism includes an orifice member 32 (fixed member) similar to that of the first embodiment, and a moving member 100 and a pressing elastic member SP3 described below. The moving member 100 is disposed in the flow path F <b> 23 inside the connecting member 31 so as to be movable relative to the orifice member 32 in the axial direction.

  The moving member 100 has a metal cylindrical shape extending in the axial direction, and is disposed on the downstream side of the orifice member 32. A through-hole penetrating in the axial direction is formed in the central portion of the cylinder of the moving member 100. This through hole is a part of the flow passage F, communicates with the throttle flow passage F22, and functions as a sub-throttle flow passage 103 having a smaller passage area than the throttle flow passage F22. The moving member 100 includes a seal portion 101 formed with a seal surface 101a that covers the throttle flow passage F22, and an engagement portion 102 that engages with the pressing elastic member SP3.

  The engaging portion 102 has a smaller diameter than the seal portion 101, and a coil-shaped pressing elastic member SP <b> 3 is fitted into the engaging portion 102. Thereby, the movement of the pressing elastic member SP3 in the radial direction is restricted by the engaging portion 102. One end of the pressing elastic member SP3 is supported by the lower end surface of the seal portion 101, and the other end of the pressing elastic member SP3 is supported by the connecting member 31. The pressing elastic member SP3 is elastically deformed in the axial direction to apply an elastic force to the moving member 100, and the seal surface 101a of the moving member 100 is pressed against the lower end surface of the orifice member 32 by the elastic force and is in close contact therewith.

  When the upstream side fuel pressure of the moving member 100 becomes higher than the downstream side fuel pressure by a predetermined amount or more as the valve body 30 moves in the valve opening direction, the moving member 100 becomes an orifice member against the elastic force of the pressing elastic member SP3. It separates from 32 (refer FIG. 5). When the downstream side fuel pressure of the moving member 100 becomes higher than the upstream side fuel pressure by a predetermined amount or more as the valve body 30 moves in the valve closing direction, the moving member 100 is seated on the orifice member 32 (see FIG. 4).

  In a state in which the moving member 100 is separated, a flow passage (outer peripheral flow passage F23a) through which fuel flows is formed in the gap between the outer peripheral surface of the moving member 100 and the inner peripheral surface of the connecting member 31. When the outer peripheral side flow passage F23a and the sub throttle flow passage 103 are positioned in parallel and the moving member 100 is separated, the fuel that has flowed out of the throttle flow passage F22 into the flow passage F23 is separated from the sub throttle flow passage 103. It branches and flows to the outer peripheral flow passage F23a. The total passage area of the sub-throttle flow passage 103 and the outer peripheral flow passage F23a is larger than the passage area of the restriction flow passage F22. Therefore, in the state where the moving member 100 is separated, the flow rate of the movable flow passage F20 is specified by the degree of restriction in the restriction flow passage F22.

  On the other hand, in the state where the moving member 100 is seated, the fuel that has flowed out from the throttle flow passage F22 to the flow passage F23 flows through the sub-throttle flow passage 103 and does not flow into the outer peripheral flow passage F23a. The passage area of the sub-throttle flow passage 103 is smaller than the passage area of the restriction flow passage F22. Therefore, in the state where the moving member 100 is seated, the flow rate of the movable flow passage F <b> 20 is specified by the degree of restriction in the sub-throttle flow passage 103. Accordingly, the moving member 100 is seated on the orifice member 32 to cover the throttle flow passage F22 to increase the degree of throttle, and by moving away from the orifice member 32, the throttle flow passage F22 is opened to reduce the throttle degree. .

  If the valve body 30 is moving in the valve opening direction, there is a high probability that the upstream side fuel pressure of the moving member 100 is higher than the downstream side fuel pressure by a predetermined amount or more and the moving member 100 is separated. However, if the valve body 30 is in the full lift state in which the valve body 30 has moved most in the valve opening direction and the valve body 30 has stopped moving, the probability that the moving member 100 will be seated is high.

  If the valve body 30 is moving in the valve closing direction, the downstream side fuel pressure of the moving member 100 is higher than the upstream side fuel pressure by a predetermined amount or more, and the probability that the moving member 100 is seated is high. However, when the valve opening period is shortened to reduce the injection amount from the nozzle hole 23a, injection (partial lift injection) is performed to switch the valve body 30 from the valve opening operation to the valve closing operation without moving to the full lift position. There is a case. In this case, there is a high probability that the moving member 100 is separated immediately after switching to the valve closing operation. However, in the period immediately before the valve closing after that, the downstream fuel pressure of the moving member 100 is higher than the upstream fuel pressure by a predetermined amount or more, and the probability that the moving member 100 is seated is high.

  In short, the moving member 100 is not always open during the valve opening operation of the valve body 30, and the moving member is at least in the period immediately after the valve opening in the rising period in which the valve body 30 moves in the valve opening direction. 100 is seated. Further, the moving member 100 is not always seated during the valve closing operation of the valve body 30, and the moving member 100 is at least in the period immediately before the valve closing in the descending period in which the valve body 30 moves in the valve closing direction. Is seated. Therefore, in the period immediately after the valve opening and in the period immediately before the valve closing, the moving member 100 is seated and the entire amount of fuel flows through the sub-throttle flow passage 103, so that the moving member 100 is separated from the period. The degree of restriction in the movable flow path F20 increases.

  As described above, according to the present embodiment, the movable structure M1 has the variable throttle mechanism that changes the throttle degree of the flow rate in the flow passage F. Therefore, it is possible to change the braking force by the fuel that acts on the movable structure M1.

  Furthermore, according to the present embodiment, in the valve closing operation period in which the valve body 30 moves in the valve closing direction, at least the period immediately before the valve closing, the degree of throttle by the variable throttle mechanism is greater than in the full lift state. Therefore, in the period immediately before the valve closing, the pressure difference between the two regions is increased due to the increase in the degree of throttle, so that the braking force is increased and the valve closing operation speed of the valve body 30 is decreased, and the valve body 30 is seated. The possibility of bouncing in 23 s can be reduced. On the other hand, in the full lift valve opening period, the pressure loss in the injection period can be reduced by reducing the throttle degree.

  Furthermore, according to the present embodiment, in the valve opening operation period in which the valve body 30 moves in the valve opening direction, at least the period immediately after the valve opening, the degree of throttling by the variable throttle mechanism is greater than in the full lift state. For this reason, in the period immediately after the opening of the valve, the degree of throttling increases, so that the pressure difference between the two regions increases. Therefore, the braking force increases and the valve opening speed of the valve body decreases. Therefore, at the time of the partial lift injection described above, the injection amount from the nozzle hole 23a with respect to the energization time to the coil 70 can be reduced. Therefore, it is possible to reduce variations in the characteristics of the injection amount with respect to the energization time.

  Further, in the present embodiment, the variable throttle mechanism includes the orifice member 32 (fixed member) in which the orifice 32 a (throttle portion) is formed, and the moving member 100 that moves relative to the orifice member 32. The moving member 100 is seated on the orifice member 32 to cover the throttle flow passage F22 to increase the degree of throttle, and by moving away from the orifice member 32, the throttle flow passage F22 is opened to reduce the throttle degree. Therefore, the degree of restriction can be made variable by the seating of the moving member 100, so that the variable restriction mechanism can be realized with a simple structure.

  Further, in the present embodiment, the moving member 100 is disposed on the downstream side of the orifice member 32. As the valve body 30 moves in the valve opening direction, the upstream side fuel pressure of the moving member 100 becomes higher than the downstream side fuel pressure by a predetermined amount or more, so that the moving member 100 is separated. Further, as the valve body 30 moves in the valve closing direction, the moving member is seated when the downstream side fuel pressure becomes higher than the upstream side fuel pressure by a predetermined amount or more. According to this, the diaphragm member can be made variable by moving the moving member 100 while eliminating the need for an actuator for moving the moving member 100.

  Furthermore, in this embodiment, the sub-throttle flow passage 103 that is a part of the flow passage F is formed in the moving member 100, and the passage area of the sub-throttle flow passage 103 is smaller than the passage area of the narrow flow passage F22. Contrary to this embodiment, when the sub-throttle passage 103 is not formed, there is a concern that the moving member 100 will stick to the orifice member 32 and will not easily peel off, and the moving member 100 will be difficult to separate. On the other hand, in this embodiment, since the sub-throttle flow passage 103 is formed in the moving member 100, the concern about sticking can be suppressed.

  Immediately after the valve body 30 is seated on the seating surface 23s and closed, pulsation occurs in the downstream fuel pressure PL. Therefore, in contrast to the present embodiment, when the sub throttle flow passage 103 is not formed, There is a concern that the moving member 100 repeatedly flutters and leaves according to the pulsation. On the other hand, in this embodiment, since the sub-throttle flow passage 103 is formed in the moving member 100, the concern about the fluttering can be suppressed.

(Third embodiment)
The sub-throttle passage 103 is formed in the moving member 100 of the movable structure M1 according to the second embodiment, whereas the moving member 100A of the movable structure M2 according to the present embodiment is shown in FIG. As shown, the sub-throttle flow passage 103 is not formed.

  Therefore, in the state where the moving member 100A is separated, the entire amount of fuel flowing out from the throttle flow passage F22 to the flow passage F23 flows through the outer peripheral flow passage F23a. The passage area of the outer peripheral flow passage F23a is larger than the passage area of the throttle flow passage F22. Therefore, in the state where the moving member 100A is separated, the flow rate of the movable flow passage F20 is specified by the degree of restriction in the restriction flow passage F22.

  On the other hand, in a state where the moving member 100A is seated, the moving member 100A closes the throttle flow passage F22, and fuel does not flow from the throttle flow passage F22 to the flow passage F23 inside the connecting member 31. Therefore, in a state where the moving member 100A is seated, it can be said that the flow rate of the movable flow path F20 is zero and the degree of throttling is the maximum. Therefore, the moving member 100A is seated on the orifice member 32 so as to close the throttle flow passage F22 and stop the flow of the movable flow passage F20. On the other hand, the moving member 100A is separated from the orifice member 32 to open the throttle flow passage F22 so that the fuel flows into the movable flow passage F20, that is, the throttle degree is reduced from the maximum state to the small state.

  As described above, according to the present embodiment, the moving member 100A closes the throttle flow passage F22 while seated on the orifice member 32, so that the downstream fuel pressure PL when the moving member 100A is seated can be increased. Therefore, the pressure difference ΔP between the upstream region and the downstream region with the orifice 32a as a boundary can be increased. Therefore, the braking force when the moving member 100 </ b> A is seated is greater than when the sub-throttle flow passage 103 is formed in the moving member 100. Accordingly, it is possible to promote the slowing down of the valve closing operation speed of the valve body 30 and improve the bounce reduction effect of the valve body 30.

(Fourth embodiment)
In the first embodiment, the sliding member 33 is a separate body from the movable core 40 and is disposed in a state in which the sliding member 33 can move relative to the movable core 40 in the radial direction. On the other hand, in this embodiment shown in FIG. 7, the sliding member 33 is joined to the movable core 40 by welding or the like. Accordingly, in this embodiment, the contact elastic member SP2 and the support member 24 are eliminated.

  Further, when the sliding member 33 is separated from the movable core 40 and can be moved in the radial direction as in the first embodiment, the anti-injection hole side guide portion is formed in a portion of the movable structure M excluding the sliding member 33. Is provided. In contrast, in the present embodiment in which the sliding member 33 is joined to the movable core 40, the sliding member 33 is provided with an anti-injection hole side guide portion. That is, the sliding surface 33a of the sliding member 33 functions as an anti-injection hole side guide portion.

(Fifth embodiment)
In the first embodiment, the orifice 32 a is formed in the orifice member 32, and the orifice member 32 is assembled to the movable core 40. On the other hand, in this embodiment, the orifice member 32 is abolished and the orifice 32a is directly formed in the movable core 40 as shown in FIG.

  Further, in the first embodiment, the flow path F28s by the through hole 41 is formed by three parts of the movable core 40, the connecting member 31, and the orifice member 32. In the present embodiment, the flow path F28s of the movable core 40 is formed. A through hole 41 is formed by one component. The through hole 41 communicates with the flow passage F21 located on the inner diameter side of the movable core 40 and the flow passage F26s located on the outer shape side of the movable core 40.

  Of the central hole extending in the axial direction at the center of the movable core 40, the flow passage F 21, which is a portion communicating with the side opposite to the injection hole of the orifice 32 a, communicates with the throttle flow passage F 22 and the through hole 41. It corresponds to. The passage area of the throttle flow passage F22 is smaller than the passage area of the communication flow passage. The passage area of the sliding flow passage F27s is smaller than the passage area of the throttle flow passage F22. In addition, the passage area in this specification is an area of a cross section obtained by cutting the corresponding passage in a direction orthogonal to the fuel flow direction.

  In addition, the movable core 40 according to the first embodiment has a surface to be sucked by the suction surface of the fixed core 50, and the surface to be sucked is one surface that extends perpendicular to the axial direction. . On the other hand, the movable core 40 according to the present embodiment has two sucked surfaces such as a first sucked surface 401a and a second sucked surface 402a. The first suction surface 401a is disposed opposite to the first suction surface 501a formed by the first fixed core portion 501, and is sucked by the magnetic flux passing through the air gap with the first suction surface 501a. The second attracted surface 402a is disposed opposite to the second attracting surface 502a formed by the second fixed core portion 502, and is attracted by the magnetic flux passing through the air gap with the second attracting surface 502a.

  The first suction surface 401a and the second suction surface 402a are arranged at different positions in the radial direction, and are also arranged at different positions in the axial direction. Specifically, the first suction surface 401a is disposed radially inward of the second suction surface 402a and on the nozzle hole side in the axial direction. In short, the movable core 40 according to the present embodiment is formed in a stepped shape having two suction surfaces arranged at different positions in the radial direction and the axial direction.

  A portion of the outer peripheral surface of the movable core 40 that is continuous with the first suction surface 401a is referred to as a first outer peripheral surface 401b, and a portion that is continuous with the second suction surface 402a is referred to as a second outer peripheral surface 402b. The first outer peripheral surface 401b is located radially inward of the second outer peripheral surface 402b. One end of the through hole 41 is located on the first outer peripheral surface 401b.

  A nonmagnetic member 60 is disposed between the first fixed core portion 501 and the second fixed core portion 502. Therefore, the direction of the magnetic flux passing through the first attracted surface 401a and the first attracting surface 501a and the direction of the magnetic flux passing through the second attracted surface 402a and the second attracting surface 502a are opposite to each other.

  The end surface of the 2nd fixed core part 502 and the end surface of the main-body part 21 are being fixed by welding. The part which attached | subjected the dot in FIG. 8 shows the part (welded part Y) melted and solidified by welding. A cylindrical welding cover 201 is fixed to the inner peripheral surfaces of the second fixed core portion 502 and the main body portion 21. The welding cover 201 is welded by the welded portion Y. A sliding member 202 is fixed to the inner peripheral surface of the welding cover 201 by fitting. The inner peripheral surface of the sliding member 202 supports the outer peripheral surface (sliding surface 33a) of the sliding member 33 in the radial direction in a slidable state. The inner peripheral surface of the sliding member 33 functions as a fitting surface 33 d that fits into the movable core 40.

  The welding cover 201, the sliding member 202, the injection hole member 23, and the movable core 40 are formed of different materials. Specifically, a highly magnetic material is used for the movable core 40, a highly hard material with excellent wear resistance is used for the sliding member 33 and the sliding member 202, and the welding cover 201 is welded. A material advantageous to the above is used.

  As described above, the valve body 30 is directly attached to the movable core 40 as the orifice member 32 is eliminated. Specifically, the end portion on the side opposite to the injection hole of the valve body 30 is fixed to the recess formed on the injection hole side surface (lower end surface) of the movable core 40 by fitting. A flow path F <b> 23 is formed in the end portion of the valve body 30 on the side opposite to the injection hole. The flow passage F23 inside the valve body 30 communicates with the flow passage F31 which is the downstream passage F30 through a passage hole 30h formed in the valve body 30.

  A contact member 34 is fixed by fitting into a recess formed on the surface (upper end surface) of the movable core 40 on the side opposite to the injection hole. When the valve body 30 opens and reaches the full lift position, the contact member 34 contacts the stopper 51, and the movable core 40 is prevented from contacting the fixed core 50. Further, the contact member 34 also functions as a member that supports the elastic member SP1.

  Here, contrary to the present embodiment, for example, when the orifice member 32 formed with the orifice 32a is press-fitted and fixed to the movable core 40, the orifice 32a is deformed by the press-fitting, and the passage area of the throttle flow passage F22 is desired. Concerns vary from the value of. When the orifice 32a is deformed in this way, the braking force due to the pressure difference ΔP between the upstream fuel pressure PH and the downstream fuel pressure PL described above deviates from a desired value. In this embodiment, the throttle flow passage F22 formed by the orifice 32a is formed in the movable core 40 with respect to this concern. Therefore, since the deformation of the orifice 32a due to the press-fitting deformation can be avoided, the deviation of the braking force due to the pressure difference ΔP can be reduced.

  Here, contrary to the present embodiment, for example, when the flow path F28s by the through hole 41 is formed by three parts of the movable core 40, the connecting member 31, and the orifice member 32, the fuel in the through hole 41 is each member. There is a concern of leakage from the contact surface. When such leakage occurs, the braking force due to the pressure difference ΔP described above deviates from a desired value. With respect to this concern, in the present embodiment, the movable core 40 is formed with a throttle flow passage F22 and a flow passage F21 (communication flow passage), and the communication flow passage is located on the side opposite to the injection hole of the throttle flow passage F22. Then, it communicates with the throttle flow passage F22 and the through hole 41. Therefore, since the through-hole 41 (flow passage F28s) is formed by one component of the movable core 40, fuel leakage from the through-hole 41 communicating with the communication flow passage can be avoided, and the braking force due to the pressure difference ΔP can be avoided. The deviation can be reduced.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made as illustrated below. Not only combinations of parts that clearly show that combinations are possible in each embodiment, but also combinations of the embodiments even if they are not explicitly stated unless there is a problem with the combination. Is also possible.

  In the first embodiment, the sliding member 33 is installed so as to be relatively movable in the radial direction with respect to the movable core 40. On the other hand, the sliding member 33 may be fixed to the movable core 40 by means of welding or the like and installed in a state where relative movement is impossible.

  In the said 1st Embodiment, the movable core 40 and the connection member 31 are cut separately, and it manufactures as another component, Then, each is combined and integrated by welding etc. On the other hand, you may manufacture the movable core 40 and the connection member 31 integrally as one component. For example, the movable core 40 and the connecting member 31 may be integrally formed by cutting one metal base material.

  In the said 1st Embodiment, the connection member 31 and the valve body 30 are cut separately, and it manufactures as another component, Then, each is combined and integrated by welding etc. On the other hand, you may manufacture the connection member 31 and the valve body 30 integrally as one component. For example, the connecting member 31 and the valve body 30 may be integrally formed by cutting one metal base material.

  In the first embodiment, the movable core 40, the connecting member 31, and the valve body 30 are separately cut and manufactured as separate parts. However, the movable core 40, the connecting member 31, and the valve body 30 are integrated as one part. May be manufactured. For example, the movable core 40, the connecting member 31, and the valve body 30 may be integrally formed by cutting one metal base material.

  In the said 1st Embodiment, the valve body 30 is fixed to the movable core 40 by means, such as welding, and is installed in the state which cannot be relatively moved to an axial direction. On the other hand, the valve body 30 may be installed in a state in which it can move relative to the movable core 40 in the axial direction. In this case, when the valve opening operation is performed, the valve body 30 is engaged with the movable core 40, the driving force of the movable core 40 is transmitted to the valve body 30, and the movable core 40 is sucked by the fixed core 50 and stopped. The valve body 30 is relatively movable. Further, when the valve closing operation is performed, the valve body 30 is engaged with the movable core 40 and the valve closing force of the valve body 30 is transmitted to the movable core 40 when the valve body 30 is pushed by the elastic member SP1 to perform the valve closing operation. Even after the valve body 30 is seated and the valve closing operation is stopped, the movable core 40 is relatively movable.

  In each of the above embodiments, the throttle flow passage F22 is arranged at the axial center of the movable structure M. On the other hand, the throttle flow passage F22 may be disposed at a position deviated from the axial center of the movable structure M. In this case, instead of forming the throttle flow passage F22 in the orifice member 32, it may be formed in the movable core 40, the connection member 31, or the valve body 30. Further, the throttle flow passage F22 may be arranged at the center of the axis, and another throttle flow passage may be further provided. For example, in addition to the throttle flow path F22, a throttle flow path may be formed in the movable core 40.

  Further, when the throttle flow passage F22 is arranged away from the axial center as described above, it is desirable to arrange the plurality of throttle flow passages F22 at positions that are symmetric with respect to the axial center of the movable structure M. According to this, it is possible to suppress the braking force acting on the movable structure M from being biased with respect to the axial center, and to suppress the tilting force acting on the movable structure M.

  In the first embodiment, the position of the sliding surface 33a in the direction (radial direction) perpendicular to the sliding direction of the sliding member 33 is inside the outermost peripheral position of the movable core 40, that is, the annular center line C. Located on the side. On the other hand, the position of the sliding surface 33 a may be outside the outermost peripheral position of the movable core 40.

  Moreover, in the said embodiment, the sliding part which the sliding surface 33a slides in the nozzle body 20 which is a part which accommodates the movable structure M among the bodies B is formed. On the other hand, the structure which forms the said sliding part in components different from the nozzle body 20, and couples the other components to the nozzle body 20 may be sufficient.

  Moreover, in the said embodiment, although the flow path F33 was provided between the sliding surface 33a and the body B, you may make it a fuel not flow. Or you may make the fuel which flows into the flow path F33 minute. The minute fuel is, for example, fuel that is pushed out from the sliding gap as the sliding surface 33a and the body B slide.

  Moreover, in the said embodiment, although the sliding face 33a and the body B are slid, you may make it provide the flow path F33, without making it slide. That is, the movable structure M may be structured to be accommodated in the body B so as to be movable in the axial direction without being in contact with the body B. (Flow passage).

  In the second and third embodiments, the opening / closing operation is performed so that the moving member 100 is separated and seated by the pressure difference ΔP between the downstream fuel pressure PL and the upstream fuel pressure PH and the elastic force of the pressing elastic member SP3. On the other hand, the moving member 100 may be opened and closed by an electric actuator. The moving member 100 itself may be configured to be elastically deformed to open and close, and the pressing elastic member SP3 may be eliminated.

  In the example shown in FIG. 4, the sub-throttle flow passage 103 is configured such that the passage length (the length in the axial direction) is longer than the diameter of the sub-throttle flow passage 103. Good. For example, the entire length in the axial direction of the moving member 100 may be replaced with the sub-throttle flow passage 103, and a part of the passage length may be reduced in diameter to function as a sub-throttle flow passage.

  In the fourth embodiment, the sliding member 33 is joined to the movable core 40, but may be joined to the connecting member 31, or may be joined to both the movable core 40 and the connecting member 31. . In the fourth embodiment, the sliding member 33 processed separately from the movable core 40 is joined to the movable core 40, but the sliding member 33 is processed integrally with the movable core 40. Also good. For example, the movable core 40 may be formed in a shape having a portion (sliding portion) that functions as the sliding member 33 by cutting one metal base material. Even in this case, the surface corresponding to the sliding surface 33 a of the movable core 40 is provided at a position different from the outermost peripheral position of the movable core 40.

  In the fifth embodiment, the orifice 32 a is formed directly on the movable core 40, and the flow path F <b> 28 s by the through hole 41 is formed by one component of the movable core 40. On the other hand, the flow path F28s by the through hole 41 may be formed by a plurality of parts while directly forming the orifice 32a in the movable core 40. In each of the above embodiments, the sliding flow passage F27s (separate flow passage) is provided on the injection hole side of the movable core 40, but may be provided on the counter injection hole side.

  23a ... nozzle hole, 30 ... valve body (movable structure), 31 ... connecting member (movable structure), 32 ... orifice member (movable structure), 32a ... throttle part, 33 ... sliding member (movable structure) 33a ... sliding surface, 40 ... movable core (movable structure), 50 ... fixed core, 70 ... coil, B ... body, F ... flow passage, F20 ... movable flow passage, F22 ... throttle flow passage, F27s ... slide Dynamic flow path, M, M1, M2 ... movable structure.

Claims (20)

In a fuel injection valve having an injection hole (23a) for injecting fuel, and a flow passage (F) for flowing fuel to the injection hole,
A coil (70) for generating magnetic flux when energized;
A fixed core (50) that creates a magnetic force by forming a path of the magnetic flux;
The movable flow path (F20), which has a movable core (40) that moves by the magnetic force, and a valve body (30) that is driven by the movable core and opens and closes the nozzle hole, serves as a part of the flow path. A movable structure (M, M1, M2) formed inside;
A body (B) in which the movable structure is housed in a movable state, and a part of the flow path is formed inside;
With
The movable structure has a throttle part (32a) that partially narrows the passage area of the movable flow passage to restrict the flow rate,
The flow passage is formed between the movable structure and the body, the throttle flow passage (F22), which is a flow passage by the throttle portion, and a passage through which fuel flows independently of the throttle flow passage. A separate flow path (F27s),
The passage area of the separate flow passage is smaller than the passage area of the throttle flow passage,
The fuel injection valve in which a position of the separate flow path in a direction perpendicular to a moving direction of the movable structure is different from an outermost peripheral position of the movable core. The nozzle hole side portion of the separate flow path is connected to the flow path on the nozzle hole side than the throttle flow path,
2. The fuel injection valve according to claim 1, wherein a portion of the separate flow passage on the side opposite to the injection hole is connected to a flow passage on the counter injection hole side of the throttle flow passage.   The fuel injection valve according to claim 1 or 2, wherein the separate flow passage is provided closer to the injection hole than the movable core.   The fuel injection valve according to any one of claims 1 to 3, wherein the separate flow passage is provided radially inward from the outermost periphery of the movable core.   The fuel injection valve according to any one of claims 1 to 4, wherein a material of a member forming the separate flow passage in the movable structure is different from a material of the movable core.   The movable core is formed with a through hole (41) that communicates a portion of the constricted flow passage on the side opposite to the injection hole and a portion of the separate flow passage on the side opposite to the injection hole. The fuel injection valve according to any one of claims 1 to 5. In the movable core,
The throttle flow passage;
The fuel injection valve according to claim 6, wherein a communication flow passage (F21) located on the side opposite to the injection hole of the restriction flow passage and communicating with the restriction flow passage and the through hole is formed.   The fuel injection valve according to claim 1, wherein the throttle flow passage is formed in the movable core.   The fuel injection valve according to any one of claims 1 to 8, wherein a passage area of a flow passage formed between an outermost periphery of the movable core and the body is larger than a passage area of the separate flow passage. In a fuel injection valve having an injection hole (23a) for injecting fuel, and a flow passage (F) for flowing fuel to the injection hole,
A coil (70) for generating magnetic flux when energized;
A fixed core (50) that creates a magnetic force by forming a path of the magnetic flux;
The movable flow path (F20), which has a movable core (40) that moves by the magnetic force, and a valve body (30) that is driven by the movable core and opens and closes the nozzle hole, serves as a part of the flow path. A movable structure (M, M1, M2) formed inside;
A body (B) in which the movable structure is housed in a slidable state, and a part of the flow path is formed inside;
With
The movable structure has a throttle part (32a) that partially narrows the passage area of the movable flow passage to restrict the flow rate, and a sliding surface (33a) with the body,
The flow path includes a throttle flow path (F22) that is a flow path by the throttle unit,
The fuel injection valve, wherein a position of the sliding surface in a direction perpendicular to a sliding direction of the movable structure is different from an outermost peripheral position of the movable core.   The fuel injection valve according to any one of claims 1 to 10, wherein the throttle flow passage is positioned on a central axis of the valve body.   The fuel injection valve according to any one of claims 1 to 11, wherein the movable structure includes a variable throttle mechanism (100, 100A, SP3) that changes a throttle degree of a flow rate in the flow passage.   Of the descending period in which the valve body moves in the valve closing direction, at least in the period immediately before the valve closing, the degree of throttle by the variable throttle mechanism is larger than in the full lift state in which the valve body has moved most in the valve opening direction. The fuel injection valve according to claim 12.   Of the rising period in which the valve element moves in the valve opening direction, at least in the period immediately after the valve opening, the degree of throttle by the variable throttle mechanism is larger than in the full lift state in which the valve element has moved most in the valve opening direction. The fuel injection valve according to claim 12 or 13. The variable throttle mechanism includes a fixed member (32) in which the throttle portion is formed, and a moving member (100, 100A) that moves relative to the fixed member,
The moving member is seated on the fixed member to cover the throttle flow passage to increase the throttle degree, and is moved away from the fixed member to open the throttle flow path and reduce the throttle degree. The fuel injection valve according to any one of claims 12 to 14. The moving member is disposed downstream of the fixed member,
As the valve body moves in the valve opening direction, the upstream side fuel pressure of the moving member becomes higher than the downstream side fuel pressure by a predetermined amount or more, so that the moving member separates and the valve body moves in the valve closing direction. Accordingly, the fuel injection valve according to claim 15, wherein the moving member is seated when the downstream fuel pressure becomes higher than the upstream fuel pressure by a predetermined amount or more. The moving member is formed with a sub-throttle flow passage (103) that is a part of the flow passage,
The fuel injection valve according to claim 15 or 16, wherein a passage area of the sub throttle passage is smaller than a passage area of the throttle passage.   The fuel injection valve according to claim 15 or 16, wherein the moving member closes the throttle flow passage while being seated on the fixed member.   The movable structure includes a sliding member (33) that forms a sliding surface (33a) with the body, and an adhesion elastic member (SP2) that presses the sliding member against the movable core to closely contact the body. The fuel injection valve according to any one of claims 1 to 18. Of the flow passage, the passage area on the seat surface (30 s) on which the valve body is separated and seated, the passage area in the full lift state in which the valve body has moved most in the valve opening direction is defined as a seat passage area,
The fuel injection valve according to any one of claims 1 to 19, wherein a passage area of the throttle flow passage is larger than the seat passage area.

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