JP4810273B2 - Fuel injection valve - Google Patents

Description

  The present invention relates to a fuel injection valve mainly used in a fuel supply system of an internal combustion engine, and in particular, a valve body that can be seated on a valve seat connected to an inner end of a fuel injection hole, and urges the valve body in a seating direction. The present invention relates to a fuel injection valve including a return spring, an electromagnetic actuator that operates the valve body in an inward opening direction when energized, and a magnetostrictive actuator that extends a movable part assembly extending from the valve body to a movable core of the electromagnetic actuator by energization.

Conventionally, a fuel injection valve including a magnetostrictive actuator that opens and closes a valve body by quickly expanding and contracting a magnetostrictive element by applying and releasing a magnetic field is already known as disclosed in Patent Documents 1 and 2.
JP 2002-295330 A JP 2000-257527 A

  By the way, what is disclosed in Patent Document 1 is that a magnetostrictive element of a magnetostrictive actuator is formed in a hollow cylindrical shape surrounding a valve body, and one end on the valve seat side of this magnetostrictive element is fixed to a valve housing, and the other end However, it is difficult to obtain a sufficient amount of extension due to the hollowing of the magnetostrictive element. In order to obtain this, an extremely long magnetostrictive element is required, which leads to an increase in the length of the fuel injection valve, and due to an increase in the weight of the movable part including the valve body, the response of the movable part is reduced or the movable part and the fixed part are The amount of wear at the contact portion increases.

  In addition, what is disclosed in Patent Document 2 uses a solid magnetostrictive element, and the movable part including the valve body is downsized, and has an outward opening structure. The valve part of the valve body located is difficult to form the desired fuel spray foam.

  Further, the devices disclosed in Patent Documents 1 and 2 open and close the valve body only by expansion and contraction of the magnetostrictive actuator, so that power consumption increases.

  The present invention has been made in view of such circumstances, and is a combination of an electromagnetic actuator and a magnetostrictive actuator having a solid magnetostrictive element. An object is to provide a possible fuel injection valve.

In order to achieve the above object, the present invention provides a valve body that can be seated on a valve seat connected to the inner end of a fuel injection hole, a return spring that biases the valve body in a seating direction, and the valve body by energization. A fuel injection valve comprising: an electromagnetic actuator that operates in an inward opening direction; and a magnetostrictive actuator that extends a movable part assembly extending from the valve body to a movable core of the electromagnetic actuator by energization, wherein the magnetostrictive actuator includes the valve body A solid magnetostrictive element provided so as to connect them to the movable core of the electromagnetic actuator, and an axial compression preload on the magnetostrictive element between the valve body and the movable core. in the preload spring which is provided so as to impart a second coil to the separate conduction control the electromagnetic actuator is made and extended against the magnetostrictive element to the preload by the energization Is formed, the second coil, wherein the valve body, the movable core, with attached to a valve housing containing a magnetostrictive element and preload spring, within the valve housing, said valve body and valve housing, the movable core, A fuel flow path connected to the fuel injection hole is formed between the magnetostrictive element and the preload spring, and the electromagnetic actuator is disposed at one end of a core housing cylinder of the magnetic body that houses the movable core of the valve housing. The first feature is that the first coil housing cylinder for forming the magnetic path to be accommodated and the second coil housing cylinder for forming the magnetic path for accommodating the second coil are respectively coupled to the other end . The

The present invention also provides a valve body that can be seated on a valve seat that is connected to the inner end of the fuel injection hole, a return spring that biases the valve body in the seating direction, and an electromagnetic that operates the valve body in an inward opening direction when energized. A fuel injection valve comprising: an actuator; and a magnetostrictive actuator for extending a movable part assembly extending from the valve body to a movable core of the electromagnetic actuator by energization, wherein the magnetostrictive actuator includes the valve body and the movable core of the electromagnetic actuator. Between the solid magnetostrictive element provided so as to connect them, and between the valve body and the movable core, a preload provided so as to apply a compressive preload in the axial direction of the valve body to the magnetostrictive element. A load spring and a second coil that is energized and controlled separately from the electromagnetic actuator and that extends the magnetostrictive element against the preload by the energization. Is attached to a valve housing that houses the valve body, the movable core, the magnetostrictive element, and the preload spring, and the valve housing, the valve body, the movable core, the magnetostrictive element, and the preload spring are included in the valve housing. A fuel flow path connected to the fuel injection hole is formed , and energization of the electromagnetic actuator is started prior to energization of the magnetostrictive actuator in anticipation of an operation delay of the electromagnetic actuator. Two features.

The present invention also provides a valve body that can be seated on a valve seat that is connected to the inner end of the fuel injection hole, a return spring that biases the valve body in the seating direction, and an electromagnetic that operates the valve body in an inward opening direction when energized. A fuel injection valve comprising: an actuator; and a magnetostrictive actuator for extending a movable part assembly extending from the valve body to a movable core of the electromagnetic actuator by energization, wherein the magnetostrictive actuator includes the valve body and the movable core of the electromagnetic actuator. Between the solid magnetostrictive element provided so as to connect them, and between the valve body and the movable core, a preload provided so as to apply a compressive preload in the axial direction of the valve body to the magnetostrictive element. A load spring and a second coil that is energized and controlled separately from the electromagnetic actuator and that extends the magnetostrictive element against the preload by the energization. Is attached to a valve housing that houses the valve body, the movable core, the magnetostrictive element, and the preload spring, and the valve housing, the valve body, the movable core, the magnetostrictive element, and the preload spring are included in the valve housing. A fuel flow path connected to the fuel injection hole is formed , and when opening the valve body, the electromagnetic actuator and the magnetostrictive actuator are first operated substantially simultaneously, and then the operating state of the electromagnetic actuator is The third feature is to release the operation of the magnetostrictive actuator or reduce the operation amount while maintaining the above.

Furthermore, the present invention provides a valve body that can be seated on a valve seat connected to the inner end of the fuel injection hole, a return spring that urges the valve body in the seating direction, and an electromagnetic that operates the valve body in an inward opening direction by energization. A fuel injection valve comprising: an actuator; and a magnetostrictive actuator for extending a movable part assembly extending from the valve body to a movable core of the electromagnetic actuator by energization, wherein the magnetostrictive actuator includes the valve body and the movable core of the electromagnetic actuator. Between the solid magnetostrictive element provided so as to connect them, and between the valve body and the movable core, a preload provided so as to apply a compressive preload in the axial direction of the valve body to the magnetostrictive element. A load spring and a second coil that is energized and controlled separately from the electromagnetic actuator and that extends the magnetostrictive element against the preload by the energization. Is attached to a valve housing that houses the valve body, the movable core, the magnetostrictive element, and the preload spring, and the valve housing, the valve body, the movable core, the magnetostrictive element, and the preload spring are disposed in the valve housing. A fuel flow path connected to the fuel injection hole is formed, and during opening of the valve body by the operation of the electromagnetic actuator, the energization to the magnetostrictive actuator is controlled to expand and contract the movable part assembly, The fourth feature is that when the valve element is closed, first, the energization of the electromagnetic actuator is interrupted while the magnetostrictive actuator is energized, and then the energization of the magnetostrictive actuator is interrupted.

According to each feature of the present invention, since the movable part assembly can be extended by extension of the magnetostrictive element by energizing the second coil, when operating the electromagnetic actuator to open the valve body, When the movable part assembly is quickly extended by energizing the two coils, the valve opening stroke of the movable core of the electromagnetic actuator is reduced accordingly, so that the valve opening response of the valve element can be improved . Even during the opening of or the valve body, by operating the magnetostrictive actuators suitably, the opening degree of the valve body, i.e. the fuel injection amount adjustment can der Runode, responsiveness in response to required characteristics of the engine and the fuel An injection rate can be obtained.

In addition, since the magnetostrictive actuator includes a solid magnetostrictive element provided so as to connect the valve body and the movable core, it is possible to give the movable part assembly a sufficient amount of expansion while avoiding an increase in the size of the magnetostrictive actuator. Can do . The valve body when the valve opens, because the inner opening condition, without interference from the valve body, it is possible to obtain a spray form desired shape of al.

In addition, during energization of the first coil, the energization amount to the second coil can be controlled regardless of this, so that the fuel injection rate can be varied, multistage injection, and the like can be controlled. At that time, in particular, in order to increase the opening degree of the valve body, the amount of energization to the second coil and the interruption of energization are performed, so that power saving can be achieved.

In particular , according to the first feature of the present invention, the magnetic core housing cylinder that accommodates the movable core is used for a magnetic path common to the electromagnetic actuator and the magnetostrictive actuator, thereby reducing the number of parts and extending the number of parts. Therefore, it can contribute to simplification and compactness of the structure.

In particular , according to the second feature of the present invention, the operation delay of the electromagnetic actuator with respect to the magnetostrictive actuator can be eliminated, and the valve opening response of the valve element can be improved.

In particular , according to the third feature of the present invention, the valve opening responsiveness of the valve body can be enhanced, and while the valve is open, the operation of the magnetostrictive actuator is canceled or the amount of operation thereof is reduced, thereby reducing the desired fuel injection. Ru it is possible to obtain the rate.

Further, particularly according to the fourth feature of the present invention, during opening of the valve, the desired fuel injection rate can be obtained by releasing the operation of the magnetostrictive actuator or reducing the operation amount thereof. When closing the valve, first, immediately after the opening of the valve body is made zero or small by energizing the electromagnetic actuator and the magnetostrictive actuator, the energization to the electromagnetic actuator is cut off. zero or is very small controlled, therefore, also due to energization cutoff to subsequent electromagnetic actuator, less closed impact, that obtained contribute to preventing vibration of the valve body.

  Embodiments of the present invention will be described below on the basis of preferred embodiments of the present invention shown in the accompanying drawings.

  1 is a longitudinal side view of a fuel injection valve for an engine of the present invention, FIG. 2 is an enlarged view of part 2 of FIG. 1, FIG. 3 is an enlarged view of part 3 of FIG. 1, and FIG. 5 is a sectional view taken along line 5-5 of FIG. 3, FIG. 6 is a partially enlarged side view of a preload spring in the fuel injection valve, FIG. 7 is a drive circuit diagram of first and second coils in the fuel injection valve, FIG. 8 is a diagram illustrating a first operation mode of the fuel injection valve, FIG. 9 is a diagram illustrating a second mode of operation of the fuel injection valve, and FIG. 10 is a diagram corresponding to FIG. 3 showing another embodiment of the present invention. is there.

  First, in FIGS. 1 to 3, reference numeral I denotes a direct injection fuel injection valve mounted on a cylinder head of an engine. In the description of the fuel injection valve I, “front” refers to the fuel injection hole 3 side, and “rear” refers to the fuel inlet side.

  A valve housing H of the fuel injection valve I includes a bottomed cylindrical valve seat member 1 having a conical valve seat 2 on a front end wall and a fuel injection hole 3 opened at the center thereof, and a rear of the valve seat member 1. A valve guide tube 4 (magnetic material) fitted to the end and liquid-tightly coupled, and a magnetostrictive housing tube 5 fitted to the rear end of the valve guide tube 4 and liquid-tightly coupled (non-magnetic) Body), a core housing cylinder 6 (magnetic body) fitted to the rear end portion of the magnetostrictive housing cylinder 5 and liquid-tightly coupled thereto, and fitted to the rear end portion of the core housing cylinder 6 to be liquid-tight An intermediate cylinder 7 (nonmagnetic body) coupled to the hollow cylinder, a hollow cylindrical fixed core 8 (magnetic body) fitted to the rear end portion of the intermediate cylinder 7 and coupled in a liquid-tight manner, and the fixed core 8 It consists of a fuel inlet tube 9 which is liquid-tightly coupled to the rear end.

  A fuel distribution pipe (not shown) for supplying high-pressure fuel is connected to the fuel inlet cylinder 9, and the inside of the valve housing H is connected to the fuel injection hole 3 from the fuel inlet cylinder 9. It becomes the fuel flow path to reach.

  A needle-like valve body 10 having a spherical valve portion that can be seated on the valve seat 2 at the front end is accommodated in the valve guide cylinder 4 so as to secure a cylindrical fuel flow path on the outer periphery thereof. The valve body 10 is opened and closed, that is, separated from and seated on the valve seat 2 to control the injection of the high-pressure fuel in the valve housing H from the fuel injection hole 3.

  A journal portion 12 that is slidably supported on the inner peripheral surface of the valve guide cylinder 4 is formed at an intermediate portion of the valve body 10, and the front and rear end surfaces of the journal portion 12 communicate with each other on the outer periphery. Thus, a chamfer for passing the fuel is provided.

  The magnetostrictive housing cylinder 5 accommodates a cylindrical preload spring 13 (non-magnetic body) and a magnetostrictive element assembly 14 disposed inside thereof. The magnetostrictive element assembly 14 includes a solid and cylindrical inner giant magnetostrictive element 15, a cylindrical outer giant magnetostrictive element 16 disposed so as to surround the inner giant magnetostrictive element 15, and the inner and outer giant magnetostrictive elements 15 and 16. An intermediate cylindrical portion 17a disposed at the front end, a front end member 17b (magnetic body) formed at the front end of the intermediate cylindrical portion 17a (non-magnetic body) and supporting the front end of the outer giant magnetostrictive element 16, and a rear end of the intermediate cylindrical portion 17a The displacement transmitting member 17 is formed of a rear end member 17c (magnetic body) that is formed at the end and supports the rear end of the inner giant magnetostrictive element 15. The displacement transmitting member 17 substantially connects the inner giant magnetostrictive element 15 and the outer giant magnetostrictive element 16 in the axial direction.

  The core housing cylinder 6 has a movable core / yoke member combined body 25 formed by connecting a yoke member 22 (magnetic body) to the front end of the movable core 24 (magnetic body) via an intermediate member 23 (nonmagnetic body). Be contained.

  On the outer periphery of the movable core 24 and the intermediate member 23, annular journal portions 18 and 19 are formed so as to protrude and slidably fit to the inner peripheral surfaces of the intermediate cylinder 7 and the core housing cylinder 6. As a result, the movable core / yoke member assembly 25 can be maintained in a stable sliding posture without inclination. Further, the side gaps of the movable core 24 and the intermediate cylinder 7, the yoke member 22 and the core housing cylinder 6 can be made uniform at all times, and the magnetic characteristics can be stabilized. In addition, friction between the movable core 24 and the intermediate cylinder 7 and between the yoke member 22 and the core housing cylinder 6 is prevented as much as possible, and therefore the durability thereof can be enhanced without performing a special wear-resistant treatment. Moreover, since the non-magnetic intermediate member 23 can freely select a material with high wear resistance, it is possible to easily ensure its own durability.

  4 and 5, the connecting structure of the yoke member 22, the intermediate member 23 and the movable core 24 constituting the movable core / yoke member combination 25 will be described. A pair of small-diameter connecting shafts 23 a and 23 b arranged in a coaxial manner are integrally formed on both end surfaces of the intermediate member 23 in the axial direction. On the other hand, connecting holes 24b and 22b are provided on the end surfaces of the movable core 24 and the yoke member 22 facing the intermediate member 23, and the connecting shafts 23a and 23b are press-fitted into the connecting holes 24b and 22b, respectively. 22-24 are connected integrally. By doing so, it is possible to easily connect the movable core 24 and the yoke member 22 while improving their coaxial accuracy.

  A plurality of recesses 24b and 22b are formed on the outer periphery of the movable core 24 and the yoke member 22 so as to be recessed toward the outer peripheral surfaces of the connecting shafts 23a and 23b, and the bottom walls of these recesses 24b and 22b are formed. Each of the connecting shafts 23a and 23b is welded to the outer periphery. The welding is preferably laser welding. By doing so, it is possible to increase the connection strength of each press-fitting portion between the intermediate member 23 and the movable core 24 and the yoke member 22. In addition, since the relatively thin bottom walls of the concave portions 24b and 22b of the movable core 24 and the yoke member 22 are welded to the connecting shafts 23a and 23b of the intermediate member 23, very little heat input is required. It is possible to avoid a deviation in the coaxial accuracy between the movable core 24, the intermediate member 23, and the yoke member 22.

  The movable core / yoke member assembly 25 configured in this way is provided with a series of through holes 26 that allow the fuel to pass between the front and rear end faces. Therefore, the fuel can smoothly pass through the movable core / yoke member assembly 25 without being obstructed by the journal portion 18 of the movable core 24 and the journal portion 19 of the intermediate member 23, and the press-fitting loss of the fuel can be suppressed. Good fuel injection characteristics can be maintained.

  In FIG. 2 again, the front end member 17 b has a guide hole 20 that is continuous with the hollow portion of the intermediate cylinder portion 17 a of the displacement transmission member 17, and is formed in the guide hole 20 at the rear end of the valve body 10. The small-diameter shaft portion 10a and a first alignment member 21 (magnetic body) interposed between the small-diameter shaft portion 10a and the inner giant magnetostrictive element 15 are slidably fitted. Between the first alignment member 21 and the inner peripheral surface of the guide hole 20, a gap that allows the inclination of the first alignment member 21 is provided. The first aligning member 21 has a front end surface formed as a spherical convex surface 21a, and is always in contact with the central portion of the flat surface 10b at the rear end of the small diameter shaft portion 10a. Therefore, even if the contact end surface of the inner giant magnetostrictive element 15 with the first aligning member 21 is slightly inclined, the first aligning member 21 is also inclined accordingly, but the spherical convex surface of the first aligning member 21 No change occurs in the contact relationship between the small diameter shaft portion 10a of 21a and the flat surface 10b.

  On the other hand, the yoke member 22 is disposed so as to contact the rear end of the outer giant magnetostrictive element 16 via the second aligning member 28. The second alignment member 28 has a guide hole 28a for slidably receiving the rear end member 17c, and the rear end surface is formed as a spherical convex surface 28b. The spherical convex surface 28b and the yoke member 22 The conical concave surface 22c formed on the front end surface is in contact. Therefore, even if the contact end surface of the outer giant magnetostrictive element 16 with the second aligning member 28 is slightly inclined, the second aligning member 28 is also inclined accordingly, but the spherical convex surface of the second aligning member 28 No change occurs in the abutting relationship of 28b with the conical concave surface 22c of the yoke member 22.

  Thus, by the cooperation of the first and second aligning members 21, 28, a preload acting line that the preload spring 13 applies to the magnetostrictive element assembly 14 via the yoke member 22 and the valve body 10 is obtained. This can be along the axis of the magnetostrictive element assembly 14, thereby avoiding unnecessary side thrust from being applied to the magnetostrictive element assembly 14 even when it is extended, thereby improving its durability. .

  As shown in FIG. 6, the preload spring 13 is formed by rolling a punching plate made of a non-magnetic spring steel plate having a large number of through holes 27, 27,. The axial end of each of the valve body 10 and the yoke in a state where a predetermined axial compressive load is applied to the inner giant magnetostrictive element 15 and the outer giant magnetostrictive element 16. The front end portion of the member 22 is press-fitted and welded to be firmly fixed. Thus, the preload spring 13 applies an axial compressive preload to the inner giant magnetostrictive element 15 and the outer giant magnetostrictive element 16 to hold it in a state of being compressed and deformed by a predetermined amount.

  The preload spring 13 having the above configuration can be formed with a small diameter so that the entire preload spring 13 is close to the outer periphery of the magnetostrictive element assembly 14, and the movable part assembly 43 extending from the movable core 24 to the valve body 10 is compactly configured. be able to. Moreover, the preload spring 13 accommodates the magnetostrictive element assembly 14 in the inside thereof, thereby protecting the magnetostrictive element assembly 14 and ensuring its durability. Since it is housed in the valve housing H together with the preload spring 13, it is not necessary to be influenced by the temperature and humidity of the outside air. Further, even if there is a misalignment between the yoke member 22 and the valve body 10, this is allowed by elastic deformation of the preload spring 13, and no extra addition is applied to the magnetostrictive element assembly 14. 14 stable operations can be ensured.

  The inner giant magnetostrictive element 15 and the outer giant magnetostrictive element 16 are each composed of a plurality of element blocks 15a, 15a; 16a, 16a that are stacked in the axial direction, and between the element blocks 15a, 15a; 16a, 16a. Shims 29 and 30 are interposed.

  As described above, the giant magnetostrictive elements 15 and 16 are divided and laminated into a plurality of element blocks, thereby ensuring a desired extension amount of the magnetostrictive element assembly 14 and maintaining the durability of the giant magnetostrictive elements 15 and 16. The length of the magnetostrictive element assembly 14 can be easily adjusted by changing the thickness of the shims 29 and 30 interposed between the element blocks 15a and 15a; 16a and 16a. Can do.

  The movable core 24 is disposed so as to face the lower end surface of the fixed core 8 with a gap α corresponding to a predetermined valve opening stroke when the valve body 10 is seated on the valve seat 2. The fixed core 8 has a hollow portion 8a communicating with both front and rear end faces thereof, and a coiled return spring 31 for urging the movable core 24 in the valve closing direction of the valve body 10 in the hollow portion 8a. In order to apply a set load to the return spring 31, a pipe-like retainer 32 that supports the fixed end thereof is provided, and the retainer 32 is fixed to the inner peripheral surface of the hollow portion 8a by screwing or press-fitting. .

  A first coil assembly 35 is disposed on the outer periphery from the rear end portion of the core housing tube 6 to the front end portion of the fixed core. The first coil assembly 35 includes a first bobbin 36 fitted to the outer peripheral surface from the rear end portion of the core housing tube 6 to the front end portion of the fixed core, and a first coil wound around the outer periphery. 37, and a first coil housing cylinder 38 (magnetic body) that accommodates the first coil assembly 35 is disposed so as to connect between the core housing cylinder 6 and the fixed core 8.

  Thus, the first fixed core 8, the movable core 24, the first coil assembly 35, the core housing cylinder 6 and the first coil housing cylinder 38 cooperate with the return spring 31 to open and close the valve body 10. The actuator A1 is configured. When the first coil 37 is energized, the magnetic flux generated thereby runs sequentially through the fixed core 8, the first coil housing cylinder 38, the core housing cylinder 6, and the movable core 24, and the movable core 24 is set by the magnetic force of the return spring 31. Therefore, the valve body 10 can be opened by suction to the fixed core 8 side.

  A second coil assembly 40 is disposed on the outer periphery of the magnetostrictive housing cylinder 5 so as to correspond to both the giant magnetostrictive elements 15 and 16. The second coil assembly 40 includes a second bobbin 41 fitted to the outer peripheral surface of the magnetostrictive housing cylinder 5 and a second coil 42 wound around the outer periphery. The second coil assembly A second coil housing cylinder 44 (magnetic body) that accommodates 40 is disposed so as to connect between the valve guide cylinder 4 and the core housing cylinder 6.

  Thus, the inner giant magnetostrictive element 15, the outer giant magnetostrictive element 16, the displacement transmitting member 17, the preload spring 13, the yoke member 22, the second coil assembly 40, the core housing cylinder 6 and the second coil housing cylinder 44. The magnetostrictive actuator A2 that can change the effective length of the movable part assembly 43 of the integral movable part from the valve body 10 to the movable core 24 is configured. When the second coil 42 is energized, the magnetic flux generated thereby sequentially travels through the second coil housing cylinder 44, the valve guide cylinder 4, both the giant magnetostrictive elements 15, 16, the yoke member 22 and the core housing cylinder 6, thereby A magnetic field is applied to the magnetostrictive elements 15 and 16, and both the giant magnetostrictive elements 15 and 16 extend in the axial direction according to the strength of the magnetic field, so that the effective length of the movable part assembly 43 can be extended. At this time, since both the giant magnetostrictive elements 15 and 16 are substantially connected to each other in the axial direction via the displacement transmitting member 17, the elongation in the axial direction of both the giant magnetostrictive elements 15 and 16 is added. The effective length of the movable part assembly 43 is increased. As a result, the magnetostrictive element assembly 14 can be reduced in size, and a desired extension amount can be secured.

  By the way, the core housing cylinder 6 (magnetic body) that constitutes a part of the valve housing H and accommodates the movable core / yoke member combined body 25 has a first coil housing (magnetic body) that accommodates the first coil 37. Since the second coil housing (magnetic body) that accommodates the second coil 42 is disposed so as to be connected and used for the common magnetic path of the electromagnetic actuator A1 and the magnetostrictive actuator A2, the number of parts can be reduced and extended. Can contribute to the simplification and compactness of the structure.

  The movable core 24 of the electromagnetic actuator A1 and the yoke member 22 constituting a part of the magnetostrictive actuator A2 are integrally connected via a non-magnetic intermediate member 23 to form a movable core / yoke member combination 25. Therefore, even when the actuators A1 and A2 are in the operating state, the interference between the magnetic flux in the movable core 24 and the magnetic flux in the yoke member 22 is blocked by the intermediate member 23, so that each actuator A1 and A2 is in a good operating state. Can be secured.

  The first bobbin 36 is integrally formed with a first coupler 47 that supports a first power supply terminal 45 that is connected to the first coil 37, and the second coil housing cylinder 44 is connected to a second coil 42 that is connected to the second coil 42. A second coupler 48 that supports the power supply terminal 46 is integrally formed.

  As shown in FIG. 7, an electronic control unit 53 is connected to the first coil 37 and the second coil 42 via a first drive circuit 51 and a second drive circuit 52, respectively. The first drive circuit 51 and the second drive circuit 52 are individually driven and controlled based on output signals from various sensors (not shown) for detecting the fuel injection timing and the operation state, and the first and second coils 37, The energization timing and energization amount of 42 are individually controlled. At that time, in particular, energization of the first coil 37 is started prior to energization of the second coil 42 in consideration of an operation delay of the electromagnetic actuator A1. By doing so, it is possible to compensate for the lower response of the electromagnetic actuator A1 than the response of the magnetostrictive actuator A2.

Next, the operation of the fuel injection valve I will be described.
<First operation mode (see FIG. 8)>
In this first operation mode, when the stroke gap between the movable core 24 and the fixed core 8 when the first and second coils 37 and 42 are not energized is α, the extension of the movable part assembly 43 due to the operation of the magnetostrictive actuator A 2. The quantity β is set such that β ≧ α, for example β = α. Utilizing this, the open / close response of the valve body 10 is improved.
(Valve closed mode)
The first and second coils 37 and 42 are in a non-energized state, and the valve body 10 is held in the valve-closed position where the valve body 10 is seated on the valve seat 2 by the urging force of the return spring 31.
[Valve opening start mode]
First, the first coil 37 is energized, and the second coil 42 is energized after a short delay. However, since the responsiveness of the electromagnetic actuator A1 including the first coil 37 is slightly lower than the responsiveness of the magnetostrictive actuator A2 including the second coil 42, actually, the attracting operation of the movable core 24 toward the fixed core 8 is not performed. Before starting, the magnetostrictive element assembly 14 expands. As a result, from the relationship of β = α, the movable core 24 quickly moves to the fixed core 8 while maintaining the valve closing position of the valve body 10. Therefore, preparation for opening the valve body 10 can be accelerated.
(Valve open mode)
By the excitation of the first coil 37, the adsorption of the movable core 24 to the fixed core 8 is ensured. Therefore, when the energization of the second coil 42 is interrupted, the magnetostrictive element assembly 14 immediately contracts by β = α due to the set load of the preload spring 13 and returns to the initial state. = Separated by α, and the valve opening response is improved. Therefore, the high-pressure fuel that has been waiting inside the valve housing H can be injected from the fuel injection hole 3 into the combustion chamber of the engine at a desired time. In addition, power can be saved by cutting off the energization of the second coil 42.

By the way, the opening of the valve body 10 is an inward opening caused by the displacement of the valve body 10 from the valve seat 2 to the inside of the valve housing H. Therefore, a spray foam formed by fuel injection from the fuel injection hole 3 is used. It can be formed satisfactorily without being obstructed by the valve portion of the valve body 10.
(Valve closing start mode)
While energizing the first coil 37, the second coil 42 is energized. Thus, when the magnetostrictive element assembly 14 is immediately expanded by the energization of the second coil 42, the valve body 10 can be quickly closed and the fuel injection can be stopped.
(Valve closed mode)
The energization of the second coil 42 is also interrupted, and the magnetostrictive element assembly 14 is contracted to the initial state. At this stage, since the residual magnetism has disappeared or drastically decreased from between the movable core 24 and the fixed core 8, the movable core 24 is pulled away from the fixed core 8 by the set load of the return spring 31 simultaneously with the magnetostrictive element assembly 14. The valve closed state of the valve body 10 can be reliably maintained.

In the valve opening mode, if the amount of energization to the second coil 42 is appropriately reduced or controlled to zero as indicated by the dotted line and the magnetostrictive element assembly 14 is extended by an appropriate amount, the valve element 10 The amount of fuel injection can be reduced by lowering the opening, which can contribute to power saving.
<Second operation mode (see FIG. 9)>
In this second operation mode, when the stroke gap with respect to the fixed core 8 of the movable core 24 when the first and second coils 37, 42 are not energized is α, the extension of the movable part assembly 43 due to the operation of the magnetostrictive actuator A2. The quantity β is set such that β <α, for example β = α / 2. By utilizing this, it is possible to improve the valve opening response of the valve body 10 and to change the fuel injection amount.
(Valve closed mode)
The first and second coils 37 and 42 are in a non-energized state, and the valve body 10 is held in the valve-closed position where the valve body 10 is seated on the valve seat 2 by the urging force of the return spring 31. In this state, a gap α corresponding to the maximum valve opening stroke of the valve body 10 is generated between the movable core 24 and the fixed core 8.
[Valve opening start mode]
First, the first coil 37 is energized, and the second coil 42 is energized after a short delay. However, since the responsiveness of the electromagnetic actuator A1 including the first coil 37 is slightly lower than the responsiveness of the magnetostrictive actuator A2 including the second coil 42, actually, the attracting operation of the movable core 24 toward the fixed core 8 is not performed. Before starting, the magnetostrictive element assembly 14 is extended by β = α / 2, so that the stroke gap between the movable core 24 and the fixed core 8 is reduced from α to α / 2, thereby the first coil 37. Adsorption of the movable core 24 to the fixed core 8 by the excitation of can be accelerated.
(Large valve opening mode)
The energization of the first coil 37 is continued, and the energization of the second coil is cut off. By continuing the energization to the first coil 37, the movable core 24 is immediately adsorbed to the fixed core 8 by the above action, and the valve body 10 is opened. At the same time, the energization to the second coil is cut off. Since the elongation α / 2 of the magnetostrictive element assembly 14 disappears, the valve body 10 is eventually separated from the maximum stroke amount α valve seat 2 and is fully opened, and a large amount of fuel is injected from the fuel injection hole 3. Can do. In addition, power can be saved by cutting off the energization of the second coil 42.
[Small valve opening mode]
Energization of the first coil 37 is maintained, and energization of the second coil is resumed. Then, in a state where the movable core 24 is attracted to the fixed core 8, the magnetostrictive element assembly 14 is again extended by α / 2, so that the valve body 10 is in a half-open state close to the valve seat 2 by α / 2, The fuel injection amount from the fuel injection hole 3 can be halved.
(Valve closing start mode)
The energization to the first coil 37 is cut off while the energization to the second coil 42 is maintained. As a result, the valve body 10 is seated on the valve seat 2 by the biasing force of the return spring 31 from the half-open state, so that the valve closing impact is small and vibration of the valve body 10 can be prevented.
(Valve closed mode)
Finally, the power supply to the second coil 42 is also cut off. Accordingly, the movable part assembly 43 contracts, but the valve closing state due to the urging force of the return spring 31 of the valve body 10 is not changed.

  Next, another embodiment of the present invention shown in FIG. 10 will be described.

  In this other embodiment, the preload spring 13 is formed of a non-magnetic steel plate bellows body, and the yoke member 22 and the end of the valve body 10 are press-fitted and welded to the openings at both ends in the axial direction. The inside of the load spring 13 is sealed. Since other configurations are the same as those of the previous embodiment, portions corresponding to those of the previous embodiment in FIG. 10 are denoted by the same reference numerals, and redundant description is omitted.

  According to this embodiment, the inside of the preload spring 13 is hermetically sealed, so that the magnetostrictive element assembly 14 is cut off from the fuel in the valve housing H, and the performance degradation of each of the giant magnetostrictive elements 15 and 16 is reduced. Can be suppressed.

  The present invention is not limited to the above embodiments, and various design changes can be made without departing from the scope of the invention. For example, the relationship and operation mode of α and β can be freely changed according to the required characteristics of the engine.

The longitudinal section side view of the fuel injection valve for engines of the present invention. FIG. 2 is an enlarged view of part 2 of FIG. 1. 3 is an enlarged view of part 3 of FIG. FIG. 4 is a sectional view taken along line 4-4 of FIG. FIG. 5 is a sectional view taken along line 5-5 of FIG. A partially enlarged side view of a preload spring in the fuel injection valve. The drive circuit diagram of the 1st and 2nd coil in the fuel injection valve. Explanatory drawing of the 1st operation | movement aspect of the fuel injection valve. Explanatory drawing of the 2nd operation | movement aspect of the fuel injection valve. FIG. 4 is a view corresponding to FIG. 3 showing another embodiment of the present invention.

I ... Fuel injection valve H ... Valve housing A1 ... Electromagnetic actuator A2 ... Magnetostrictive actuator 2 ... Valve seat 3 ... Fuel injection hole 10 ... ... Valve element 13 ... Preload spring 15 ... Solid magnetostrictive element (inner giant magnetostrictive element)
24 ··· movable core 31 ··· return spring 37 ··· first coil 38 ··· first coil housing tube 42 ··· second coil 43 ··· second coil housing tube

Claims (4)

A valve body (10) seatable on a valve seat (2) connected to the inner end of the fuel injection hole (3), a return spring (31) for urging the valve body (10) in the seating direction, An electromagnetic actuator (A1) that operates the valve body (10) in the inward opening direction, and a movable part assembly (43) extending from the valve body (10) to the movable core (24) of the electromagnetic actuator (A1) by energization. A fuel injection valve comprising a magnetostrictive actuator (A2)
The magnetostrictive actuator (A2) is a solid magnetostrictive element (15) provided between the valve body (10) and the movable core (24) of the electromagnetic actuator (A1) so as to connect them; during the valve body (10) and the movable core (24), wherein the pre-I if heavy provided so as to impart a compressive preload in the axial direction of the valve body (10) in the magnetostrictive element (15) (13), wherein A second coil (42) that is energized and controlled separately from the electromagnetic actuator (A1) and that extends the magnetostrictive element (15) against the preload by the energization ,
The second coil (42) is attached to a valve housing (H) that houses the valve body (10), the movable core (24), the magnetostrictive element (15), and the preload spring (13). (H) includes the fuel injection hole (3) between the valve housing (H) and the valve body (10), the movable core (24), the magnetostrictive element (15) and the preload spring (13). ) Is formed,
A first coil housing cylinder for forming a magnetic path for accommodating the electromagnetic actuator (A1) at one end of a magnetic core housing cylinder (6) for accommodating the movable core (24) of the valve housing (H). The fuel injection valve according to claim 38, wherein a second coil housing cylinder (44) for forming a magnetic path for accommodating the second coil (42) is coupled to the other end . A valve body (10) seatable on a valve seat (2) connected to the inner end of the fuel injection hole (3), a return spring (31) for urging the valve body (10) in the seating direction, An electromagnetic actuator (A1) that operates the valve body (10) in the inward opening direction, and a movable part assembly (43) extending from the valve body (10) to the movable core (24) of the electromagnetic actuator (A1) by energization. A fuel injection valve comprising a magnetostrictive actuator (A2)
The magnetostrictive actuator (A2) is a solid magnetostrictive element (15) provided between the valve body (10) and the movable core (24) of the electromagnetic actuator (A1) so as to connect them; A preload spring (13) provided between the valve body (10) and the movable core (24) to apply an axial compression preload of the valve body (10) to the magnetostrictive element (15); A second coil (42) that is energized and controlled separately from the electromagnetic actuator (A1) and that extends the magnetostrictive element (15) against the preload by the energization,
The second coil (42) is attached to a valve housing (H) that houses the valve body (10), the movable core (24), the magnetostrictive element (15), and the preload spring (13). (H) includes the fuel injection hole (3) between the valve housing (H) and the valve body (10), the movable core (24), the magnetostrictive element (15) and the preload spring (13). ) Is formed,
A fuel injection valve characterized in that energization of the electromagnetic actuator (A1) is started prior to energization of the magnetostrictive actuator (A2) in consideration of an operation delay of the electromagnetic actuator (A1). A valve body (10) seatable on a valve seat (2) connected to the inner end of the fuel injection hole (3), a return spring (31) for urging the valve body (10) in the seating direction, An electromagnetic actuator (A1) that operates the valve body (10) in the inward opening direction, and a movable part assembly (43) extending from the valve body (10) to the movable core (24) of the electromagnetic actuator (A1) by energization. A fuel injection valve comprising a magnetostrictive actuator (A2)
The magnetostrictive actuator (A2) is a solid magnetostrictive element (15) provided between the valve body (10) and the movable core (24) of the electromagnetic actuator (A1) so as to connect them; A preload spring (13) provided between the valve body (10) and the movable core (24) to apply an axial compression preload of the valve body (10) to the magnetostrictive element (15); A second coil (42) that is energized and controlled separately from the electromagnetic actuator (A1) and that extends the magnetostrictive element (15) against the preload by the energization,
The second coil (42) is attached to a valve housing (H) that houses the valve body (10), the movable core (24), the magnetostrictive element (15), and the preload spring (13). (H) includes the fuel injection hole (3) between the valve housing (H) and the valve body (10), the movable core (24), the magnetostrictive element (15) and the preload spring (13). ) Is formed,
When the valve element (10) is opened, first, the electromagnetic actuator (A1) and the magnetostrictive actuator (A2) are operated substantially simultaneously, and then the operating state of the electromagnetic actuator (A1) is maintained. The fuel injection valve characterized in that the operation of the magnetostrictive actuator (A2) is canceled or the operation amount thereof is reduced. A valve body (10) seatable on a valve seat (2) connected to the inner end of the fuel injection hole (3), a return spring (31) for urging the valve body (10) in the seating direction, An electromagnetic actuator (A1) that operates the valve body (10) in the inward opening direction, and a movable part assembly (43) extending from the valve body (10) to the movable core (24) of the electromagnetic actuator (A1) by energization. A fuel injection valve comprising a magnetostrictive actuator (A2)
The magnetostrictive actuator (A2) is a solid magnetostrictive element (15) provided between the valve body (10) and the movable core (24) of the electromagnetic actuator (A1) so as to connect them; A preload spring (13) provided between the valve body (10) and the movable core (24) to apply an axial compression preload of the valve body (10) to the magnetostrictive element (15); A second coil (42) that is energized and controlled separately from the electromagnetic actuator (A1) and that extends the magnetostrictive element (15) against the preload by the energization,
The second coil (42) is attached to a valve housing (H) that houses the valve body (10), the movable core (24), the magnetostrictive element (15), and the preload spring (13). (H) includes the fuel injection hole (3) between the valve housing (H) and the valve body (10), the movable core (24), the magnetostrictive element (15) and the preload spring (13). ) Is formed,
While the valve element (10) is opened by the operation of the electromagnetic actuator (A1), the energization to the magnetostrictive actuator (A2) is controlled to expand and contract the movable part assembly (43), and the valve element (10) When closing the valve, first, the energization of the electromagnetic actuator (A1) is cut off while the magnetostrictive actuator (A2) is energized, and then the energization of the magnetostrictive actuator (A2) is cut off.

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