JP2007173448A - Electromagnetic solenoid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic solenoid which improves the adsorption responsiveness, while securing power of adsorption and stroke quantity of a movable core. <P>SOLUTION: The electromagnetic solenoid comprises a first coil 16 arranged around a fixed core 14, a second coil 22 arranged around a movable core 20 adjoining and provided in the fixed core, a fixed core and middle core 24 arranged movably between the fixed core and the movable core, and a first adsorption 34, consisting of the gap formed between the fixed core and the middle core so as to turn and move the middle core to the fixed core, when the first coil is magnetized. Furthermore, the electromagnetic solenoid comprises a second adsorption 36, consisting of the gap formed between the movable core and the middle core so as to turn and move the middle core to the middle core, when the second coil is magnetized; and an external movable core 26 where one end 26a is joined to a middle core, and also other end 26b is brought into contact with the movable core, while being arranged at the outside of the second coil. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electromagnetic solenoid.

  2. Description of the Related Art Conventionally, in an electromagnetic solenoid, for example, an electromagnetic solenoid for a fuel injection valve (injector) of an internal combustion engine, it is desired to increase the suction force of a movable core that operates the fuel injection valve in response to a demand for high pressure of the injected fuel. .

Therefore, in the following Patent Document 1, a plurality of suction gaps are provided in the direction in which the movable core is sucked, and thereby the area of the surface where the sucked movable core and the fixed-side yoke (fixed core) face each other is increased. Has been proposed. Similarly, Patent Document 2 below proposes increasing the suction force by increasing the area of the surface where the movable core and the fixed core face each other.
Japanese Patent Laid-Open No. 10-196486 JP 11-044275 A

  Incidentally, in the electromagnetic solenoid, it is necessary to improve the rising characteristics of the coil current, that is, the suction responsiveness of the movable core, in order to improve the control accuracy by energizing the coil. Generally, the suction responsiveness of the movable core is improved in inverse proportion to the coil inductance, and thus is improved by reducing the number of coil turns.

  However, since the attractive force of the movable core is proportional to the square of the number of turns of the coil, if the number of turns of the coil is simply reduced in order to improve the attractive response of the movable core, the attractive force of the movable core decreases.

  On the other hand, if the distance (suction gap) between the surfaces of the movable core and the fixed core facing each other is reduced, the suction force of the movable core can be increased and the suction responsiveness of the movable core can be improved. However, reducing the suction gap is equivalent to reducing the displacement amount (stroke amount) of the movable core, which is not preferable in terms of the characteristics of the electromagnetic solenoid. For example, in the case of an electromagnetic solenoid for an injector, if the stroke amount of the movable core is reduced, the fuel injection amount per unit time is reduced, leading to a decrease in the performance of the electromagnetic solenoid for the injector.

  As described above, conventionally, in the electromagnetic solenoid, the suction responsiveness of the movable core is ensured from the reciprocal relationship between the suction force, suction responsiveness and stroke amount of the movable core while securing the suction force and stroke amount of the movable core. It was difficult to improve.

  Accordingly, an object of the present invention is to provide an electromagnetic solenoid that solves the above-described problems and improves the suction responsiveness while securing the suction force and stroke amount of the movable core.

  In order to solve the above object, in the electromagnetic solenoid according to claim 1, the first coil disposed around the fixed core and the movable core provided adjacent to the fixed core are disposed. A second coil that is moved, an intermediate core that is movably disposed between the fixed core and the movable core, and the intermediate core is moved toward the fixed core when the first coil is excited. When the second coil is energized with the first attraction portion formed by a gap formed between the fixed core and the intermediate core, the movable core is moved toward the intermediate core. A second suction portion comprising a gap formed between the intermediate core and the movable core, and an outer end of the second coil and one end joined to the intermediate core, the other end Is brought into contact with the movable core Part was configured with the movable core.

  Further, in claim 2, a first spring that urges the other end of the external movable core to contact the movable core, and a spring coefficient larger than that of the first spring. And a second spring that urges the movable core in a direction in which the movable core is separated from the fixed core.

  According to a third aspect of the present invention, the movable core includes a reduced diameter portion whose outer diameter is reduced at one end thereof, and the other end of the outer movable core is in contact with the reduced diameter portion. Configured.

  In the electromagnetic solenoid according to claim 1, the first coil disposed around the fixed core, the second coil disposed around the movable core provided adjacent to the fixed core, and the fixed An intermediate core movably disposed between the core and the movable core, and a gap formed between the fixed core and the intermediate core to move the intermediate core toward the fixed core when the first coil is excited A first suction portion comprising: a second suction portion comprising a gap formed between the intermediate core and the movable core to move the movable core toward the intermediate core when the second coil is excited; And an outer movable core arranged on the outside of the second coil and having one end joined to the intermediate core and the other end abutted against the movable core, in other words, When the coil is divided into the first and second coils, Since the first and second suction portions for moving the movable core when the first and second coils are excited are provided, the suction force and displacement amount (stroke amount) of the movable core are secured. The suction responsiveness can be improved.

  The electromagnetic solenoid according to claim 2 further includes a first spring that urges the other end of the external movable core to abut against the movable core, and a larger spring coefficient than the first spring. And a second spring that urges the movable core in a direction away from the fixed core, so that when the excitation of the first and second coils is turned off, the movable core, the external movable core, and The intermediate core can be returned to the initial position. Further, when only the second coil is excited, the gap of the first suction portion can be held.

  In the electromagnetic solenoid according to claim 3, the movable core includes a reduced diameter portion whose outer diameter is reduced at one end thereof, and the other end of the outer movable core is in contact with the reduced diameter portion. Since it comprised, when only the 1st coil is excited, the gap | interval of a 2nd attraction | suction part can be hold | maintained.

  The best mode for carrying out an electromagnetic solenoid according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a longitudinal sectional view of an electromagnetic solenoid according to the present invention. FIG. 1 shows the electromagnetic solenoid in a state where current is not applied.

  1 is an electromagnetic solenoid used for a fuel injection valve of an internal combustion engine. As shown in FIG. 1, the electromagnetic solenoid 10 includes a case body 12, a fixed core 14 fixed to the case body 12, a first coil 16 disposed around the fixed core 14, and a fixed core. 14, a movable core 20 provided adjacent to the movable core 20, a second coil 22 disposed around the movable core 20, an intermediate core 24 disposed between the fixed core 14 and the movable core 20, and a second An external movable core 26 disposed outside the coil 22 is provided. As shown in FIG. 1, the movable core 20 includes a reduced diameter portion 20a whose outer diameter is reduced at one end, one end 26a of the outer movable core 26 is joined to the intermediate core 24, and the other end 26b is movable. It abuts on the reduced diameter portion 20 a of the core 20.

  Further, the electromagnetic solenoid 10 urges the other end 26 b of the external movable core 26 to contact the reduced diameter portion 20 a of the movable core 20, and the direction in which the movable core 20 is separated from the fixed core 14. A second spring 32 is provided for biasing. The spring constant of the second spring 32 is set larger than that of the first spring 30. For example, the spring constant of the second spring 32 is set to about 10 times that of the first spring 30.

  The spring constant of the second spring 32 is set larger than that of the first spring 30, one end 26 a of the external movable core 26 is connected to the intermediate core 24, and the other end 26 b is a reduced diameter of the movable core 20. As shown in FIG. 1, the movable core 20, the outer movable core 26, and the intermediate core 24 have the intermediate core 24 as the second coil 22 (specifically, the second coil 22). The coil hobbin 52) is fixed at a position where it abuts. Here, as shown in FIG. 1, the dimension (thickness) in the axial direction of the intermediate core 24 is set such that a gap of a predetermined distance is formed between the intermediate core 24 and the fixed core 14. Further, the axial dimension (length) of the movable core 20 to the reduced diameter portion 20 a and the axial dimension (length) of the external movable core 26 are the predetermined values described above between the movable core 20 and the intermediate core 24. The gap is set to be the same as the distance.

  Accordingly, a first suction portion 34 is formed between the fixed core 14 and the intermediate core 24. The first suction portion 34 includes a gap that should move the intermediate core 24 toward the fixed core 14 when the first coil 16 is excited. The In addition, a second suction portion 36 is formed between the intermediate core 24 and the movable core 20. The second suction portion 36 includes a gap for moving the movable core 20 toward the intermediate core 24 when the second coil 22 is excited. The

  Further, the electromagnetic solenoid 10 includes a non-magnetic outer case 38 for guiding the movement of the external movable core 26 when it moves. In addition, the electromagnetic solenoid 10 includes a coupler connector 40 for connecting to a terminal described later on the outside of the case body 12.

  One end of the movable core 20 is connected to the needle valve 46 of the valve seat assembly 44. When the movable core 20 is moved by the excitation of the first and second coils 16, 22, a gap is formed at the tip of the needle valve 46, Fuel is injected from there. The case body 12, the fixed core 14, the movable core 20, the intermediate core 24, and the external movable core 26 are made of a soft magnetic material such as iron.

  The first coil 16 and the second coil 22 are formed by winding a copper wire around a first coil bobbin 50 and a second coil bobbin 52, respectively. The first coil bobbin 50 is fixed to the case body 12 by an appropriate method.

  Hereinafter, the first and second coil bobbins 50 and 52, the intermediate core 24, and the external movable core 26 will be described for each component in FIGS.

  FIG. 2 is a perspective view of the first coil bobbin 50 and the second coil bobbin 52.

  As shown in FIG. 2, the first and second coil bobbins 50 and 52 are connected by a plurality of, specifically, two connecting members 54. An accommodating portion 56 for accommodating the intermediate core 24 is secured between the first and second coil bobbins 50 and 52 connected by the connecting member 54. Here, the connecting member 54 is formed at the same position as the outer periphery of the edge portions 50a, 52a or at an inner position thereof so as not to protrude from the outer periphery of the edge portions 50a, 52a of the first and second coil bobbins 50, 52. The first and second coil bobbins 50 and 52 and the connecting member 54 are integrally formed by an appropriate method such as insert molding. The first coil bobbin 50 is provided with four terminals 60a, 60b, 60c, 60d for connecting a copper wire wound around one end thereof.

  FIG. 3 is a perspective view of the intermediate core 24.

  As shown in FIG. 3, the intermediate core 24 has a donut shape. However, when the intermediate core 24 is accommodated in the accommodating portions 56 of the first and second coil bobbins 50 and 52, the outer periphery thereof is partially not to interfere with the connecting member 54. Cut. Further, the outer diameter of the outer peripheral portion of the intermediate core 24 that is not partially cut is set to be larger than the outer diameters of the edge portions 50a and 52a of the first and second coil bobbins shown in FIG. A taper surface 24 a is formed on one end surface of the intermediate core 24.

  FIG. 4 is a perspective view of the external movable core 26.

  As shown in FIG. 4, the outer movable core 26 has a cylindrical shape, and an inner diameter thereof is set to be substantially equal to an outer diameter of the intermediate core 24 so that one end 26 a is fitted and joined to the intermediate core 24. . On the other hand, the other end 26 b of the external movable core 26 is provided with a hole 26 c having a size suitable for inserting the movable core 20. As described above, one end of the movable core 20 is reduced in diameter, and the size of the hole 26c of the outer movable core is a size suitable for inserting the reduced diameter portion of the movable core 20.

  FIG. 5 is an explanatory view showing an assembled state of the first and second coils 16 and 22, the intermediate core 24 and the external movable core 26.

  As shown in FIG. 5, first, a copper wire 62 is wound around the first and second coil bobbins 50 and 52. In addition, the thickness of the copper wire 62 wound is exaggerated. Next, the intermediate core 24 is accommodated in the accommodating portions 56 of the first and second coil bobbins 50 and 52 so as not to interfere with the connecting member 54. Therefore, the intermediate core 24 is movable in the direction of arrow A in the drawing in the accommodating portion 56. Next, the external movable core 26 is inserted from the second coil 22 side, and the external movable core 26 is fitted and joined to the intermediate core 24 (FIG. 5 shows a state immediately before the fitting). Here, even if the outer movable core 26 is joined to the intermediate core 24, the inner diameter of the outer movable core 26 is larger than the outer diameter of the edge 52a of the second coil bobbin. Therefore, the intermediate core 24 and the external movable core 26 are movable in the direction of arrow A.

  The first and second coils 16 and 22 are formed by winding a copper wire 62 around the first and second coil bobbins 50 and 52. The details will be described below.

  FIG. 6 is an explanatory view schematically showing a state in which the copper wire 62 is wound around the first coil bobbin 50. In FIG. 6, for convenience of explanation, a part of the first and second coil bobbins 50 and 52 are cut out.

  The copper wire 62 is connected to one terminal 60b among the four terminals described above, and in the illustrated direction, specifically, on the central axis of the first and second coil bobbins 50 and 52, the first coil bobbin 50 When viewed from the side, it is wound clockwise and connected to one of the four terminals 60a. Thereby, the first coil 16 is formed.

  FIG. 7 is an explanatory view schematically showing a state in which the copper wire 62 is wound around the second coil bobbin 52. As in FIG. 6, in FIG. 7, the first and second coil bobbins 50 and 52 are partly cut out for convenience of explanation.

  The copper wire 62 is connected to one terminal 60d of the four terminals described above, passes through the first coil bobbin 50 and the connecting member 54, and passes through the second coil bobbin 52 in the direction shown in the figure, specifically, When viewed from the first coil bobbin 50 side on the central axis of the first and second coil bobbins 50 and 52, the coil bobbin 50 is wound counterclockwise, passes through the connecting member 54 and the first coil bobbin 50, and has four terminals. Are connected to one terminal 60c. Thereby, the second coil 22 is formed. As shown in FIG. 8, the connecting member 54 is formed with a groove 64 for accommodating the copper wire 62. Thereby, the copper wire 62 passing through the connecting member 54 does not interfere with the outer movable core 26. Further, as shown in FIG. 9, the conductor 66 may be insert-molded in the connecting member 54 and the copper wire 62 may be connected.

  FIG. 10 is an explanatory diagram schematically showing the direction of the magnetic flux generated in the magnetic circuit when the first and second coils are energized. Although the external movable core 26 is also shown in FIG. 10, a part of the external movable core 26 is cut out for convenience of explanation.

  The four terminals 60a, 60b, 60c, 60d are electrically connected outside the first and second coil bobbins 50, 52. For example, two of the four terminals 60b and 60c are connected, the first and second coils 16 and 22 are energized in series via the terminals 60a and 60d, and FIGS. When a current is applied in the direction shown in FIG. 10, a magnetic flux 70 in the direction shown in FIG. 10 is generated.

  As shown in FIG. 10, the intermediate core 24 disposed between the first and second coils 16 and 22 and a part of the outer movable core 26 are identically generated by the first and second coils 16 and 22. A magnetic flux 70 is generated in the direction (direction from the inside to the outside). That is, a part of each magnetic circuit generated by the first and second coils 16 and 22 is shared by a part of the intermediate core 24 and the external movable core 26. In other words, the intermediate core 24 and a part of the external movable core 26 are commonly used as part of the respective magnetic circuits generated by the first and second coils 16 and 22.

  Next, the electric circuit of the electromagnetic solenoid 10 will be described.

  FIG. 11 is an electric circuit diagram of the first and second coils 16 and 22 of the electromagnetic solenoid.

  As shown in FIG. 11, the first and second coils 16 and 22 are electrically connected in series. A current is supplied to the first and second coils 16 and 22 from a power supply means including an appropriate power supply 80, a step-down resistor 82, and a main switch 84. As shown in FIG. 11, the power supply means is connected to the upstream side of the first coil 16.

  Further, a first (NPN type) transistor 90 for turning on / off the energization of the second coil 22 is connected to the downstream side of the second coil 22. Further, a branch point is provided between the first coil 16 and the second coil 22 to connect a second (NPN type) transistor 92. As described above, the first coil bobbin 50 is provided with the four terminals 60a, 60b, 60c and 60d, and the copper wire 62 wound around the first and second coil bobbins 50 and 52 is connected to the first and second coil bobbins. The reason why the second transistors 92 and 52 are connected to each other is to connect the second transistor 92 between the first and second coils 16 and 22.

  When an off signal is transmitted from the controller (not shown) to the base of the first transistor 90 and an on signal is transmitted to the base of the second transistor 92, only the first coil 16 is energized. Thereby, only the first coil 16 is excited. Hereinafter, energization conducted only to the first coil 16 is referred to as “first coil one-side energization”. In this case, when the first coil 16 and the second coil 22 are interchanged, that is, when the second coil 22 is connected to the upstream side and the first coil 16 is connected to the downstream side, the second coil 22 is replaced. Only is excited. Hereinafter, energization conducted only to the second coil is referred to as “second coil one-side energization”.

  On the other hand, when an off signal is transmitted from the controller (not shown) to the base of the second transistor 92 and an on signal is transmitted to the base of the first transistor 90, both the first coil and the second coil 16 are used. Current (electrically in series). Thereby, both the first coil 16 and the second coil 22 are excited. Hereinafter, energization in which the first coil 16 and the second coil 22 are electrically energized in series is referred to as “series energization”.

  Next, operations of the movable core 20, the external movable core 26, and the intermediate core 24 in the case of the first coil one-side energization, the second coil one-side energization, and the series energization will be described.

  FIG. 12 is a longitudinal sectional view of the electromagnetic solenoid 10 similar to that in FIG. 1 when the first coil one side is energized. Similarly, FIG. 13 is a longitudinal sectional view of the electromagnetic solenoid 10 when energized on the second coil one side. FIG. 14 is a longitudinal sectional view of the electromagnetic solenoid 10 when energized in series.

  When the first coil 16 is excited by the first coil one-side energization, an attractive force is generated in the first attractive portion 34 by the magnetic circuit of the first coil 16. Therefore, as shown in FIG. 12, the intermediate core 24 is moved toward the fixed core 14 against the urging force of the second spring 32 and is brought into contact with the fixed core 14. Here, one end 26 a of the outer movable core 26 is joined to the intermediate core 24, and the other end 26 b is in contact with the reduced diameter portion 20 a of the movable core 20. 20 is also moved. Further, as shown in FIG. 12, the movable core 20 is moved in the direction in which the intermediate core 24 is sucked, but is biased in the direction away from the fixed core 14 by the second spring 32. The gap between the two suction portions 36 is maintained.

  That is, when the first coil 16 is excited, the displacement amount (stroke amount) of the movable core 20 is the same as the displacement amount of the intermediate core 24 in the gap of the first suction part 34. As a result, as shown in FIG. 12, a gap corresponding to the displacement amount in the gap of the first suction portion 34 is formed at the tip of the needle valve 46, and fuel is injected.

  When the second coil 22 is excited by the second coil one-side energization, an attractive force is generated in the second suction part 36 by the magnetic circuit of the second coil 22. Therefore, as shown in FIG. 13, the movable core 20 is moved toward the intermediate core 24 against the biasing force of the second spring 32 and is brought into contact with the intermediate core 24. Here, the first spring 30 urges the outer movable core 26 to contact the reduced diameter portion 20 a of the movable core 20, but the spring constant of the second spring 32 is comparable to that of the first spring 30. Therefore, the external movable core 26 is not brought into contact with the reduced diameter portion 20a of the movable core 20. Therefore, the gap of the first suction part 34 is maintained.

  That is, when the second coil 22 is excited, the displacement amount (stroke amount) of the movable core 20 is the same as the displacement amount of the movable core 20 in the gap of the second suction part 36. As a result, as shown in FIG. 13, a gap corresponding to the amount of displacement in the gap of the second suction portion 36 is formed at the tip of the needle valve 46, and fuel is injected.

  On the other hand, when both the first coil 16 and the second coil 22 are excited by the series energization, the magnetic circuit of the first coil 16 generates an attractive force in the first attractive portion 34 and the second coil. An attractive force is generated in the second attracting part 36 by the magnetic circuit 22. Accordingly, as shown in FIG. 14, the movable core 20 is moved toward the intermediate core 24 against the biasing force of the second spring 32 and is brought into contact with the intermediate core 24. Next, the intermediate core 24 is moved toward the fixed core 14 against the urging force of the second spring 32 and is brought into contact with the fixed core 14.

  That is, when both the first coil 16 and the second coil 22 are excited, the displacement amount (stroke amount) of the movable core 20 is equal to the displacement amount of the movable core 20 in the gap of the second suction portion 36. The amount of displacement of the intermediate core 24 in the gap of one suction portion 34 is added. In other words, when the first and second coils 16 and 22 are excited, the movable core 20 is moved by the first and second suction portions 34 and 36, respectively. As a result, as shown in FIG. 14, a gap corresponding to the sum of the gap between the first suction portion 34 and the gap between the second suction portions 36 is formed at the tip of the needle valve 46, and fuel is injected.

  In the above description, when the excitation of the first and second coils 16 and 22 is turned off, the attractive force in the first and second suction portions 34 and 36 disappears, and the movable core 20, the external movable core 26, The intermediate core 24 is returned to the initial position shown in FIG. 1 by the biasing force of the first and second springs 30 and 32.

  Next, the suction force and suction response of the movable core 20 will be described.

Generally, the attractive force F of the movable core in an electromagnetic solenoid is
F = 1/2 × M ² × μ0 × S / X ² (Formula 1)
(M: magnetomotive force, μ0: air permeability, S: facing area between the movable core and the fixed core, X: distance between the fixed core and the movable core (distance of the attracting portion)). The magnetomotive force M is
M = N × I (Formula 2)
(N: number of coil turns, I: coil current). Therefore, the attractive force F is proportional to the square of the coil winding number N and the square of the coil current I.

Further, the transient formula I (t) indicating the rising characteristic of the coil current I is
I (t) = E / R (1-exp (−t / τ)) (Formula 3)
(T: time, E: applied voltage, R: equivalent series resistance, τ: time constant). The movement of the movable core is not started at the time t less than the time constant τ, but is started at the time t greater than or equal to the time constant τ. That is, the coil current I when t = τ is the operating point current, and the time constant τ is a constant indicating the suction responsiveness of the movable core. Specifically, when the time constant τ is small, the suction responsiveness of the movable core is improved.

The time constant τ is
τ = L / R (Formula 4)
(L: coil inductance). As can be seen from Equations 3 and 4, the attractive response of the movable core is inversely proportional to the coil inductance L. The coil inductance L is
L = μr × N ² × Si / l (Formula 5)
(Μr: magnetic circuit permeability, Si: coil cross-sectional area, l: coil winding width). That is, the coil inductance L is proportional to the square of the number of coil turns N.

  Here, on the premise of the above formulas 1 to 5, the suction force and suction responsiveness of the movable core is composed of, for example, a single coil (coil inductance L) having a coil winding number N, and the distance of the suction portion is represented by X And the first and second coils 16 and 22 (each having a coil inductance L / 4) having a coil turn number N / 2, respectively, The distance of the suction part 34 and the distance of the second suction part 36 will be described in comparison with the electromagnetic solenoid 10 in which the distance is set to X / 2.

  FIG. 15 is a graph showing the relationship between the suction force of the suction portion and the distance.

  In the figure, A is an attractive force curve of a coil having N coil turns, and B is an attractive force curve of a coil having N / 2 coil turns. As is apparent from Equations 1 and 2, the suction force in the suction portion is thus proportional to the square of the number of coil turns and inversely proportional to the square of the distance of the suction portion.

  In the electromagnetic solenoid 10, the number of coil turns of the first and second coils 16, 22 is set to N / 2, and the distance of the first suction part 34 and the distance of the second suction part 36 are set to X / 2. The

  Accordingly, the suction force in each of the first and second suction parts 34 and 36 is the same as the suction force of the suction part set at the coil winding number N and the distance X of the suction part (the points a and b in the figure). Equivalent to relationship).

  Here, when both the first coil 16 and the second coil 22 are excited, the displacement amount (stroke amount) of the movable core 20 is equal to the displacement amount of the movable core 20 in the gap of the second suction part 36. The amount of displacement of the intermediate core 24 in the gap of the first suction part 34 is added. Therefore, even if the distance between the first suction part 34 and the distance between the second suction parts 36 is set to X / 2, X is secured as the displacement amount (stroke amount) of the movable core 20.

  FIG. 16 is a graph showing the rising characteristics of the coil current, that is, the suction response of the movable core.

  A in the figure shows a current rising curve when a conventional electromagnetic solenoid (a coil having a coil inductance L) is energized. B in the figure shows a current rising curve when the electromagnetic solenoid 10 composed of the first and second coils (each having a coil inductance L / 4) is energized in series. As is apparent from Equations 3 and 4, the time until the operating point current is reached is proportional to the coil inductance L. That is, the suction responsiveness of the movable core is improved in inverse proportion to the coil inductance L.

  As described above, the first and second coils 16 and 22 are set to the number of coil turns N / 2 and are electrically connected in series. In this case, from Equation 5, the sum of the coil inductances of the first and second coils 16 and 22 is L / 2.

  Accordingly, as shown in FIG. 16, the operating point current arrival time in the electromagnetic solenoid 10 is ½ times the operating point current arrival time in the conventional electromagnetic solenoid. That is, the suction responsiveness of the movable core 20 of the electromagnetic solenoid 10 is improved twice as much as the suction responsiveness of the movable core of the conventional electromagnetic solenoid.

  As described above, in the electromagnetic solenoid 10 according to the first embodiment, the coil having the coil turn number N is divided into the first and second coils having the coil turn number N / 2, and the first and second coils are excited. Since the first and second suction portions 34 and 36 each having a gap of a distance X / 2 that moves the movable core 20 when being moved, the suction force and displacement amount (stroke amount) of the movable core 20 are provided. The suction responsiveness can be improved while securing the above.

  Further, the first spring 30 that urges the other end 26b of the external movable core 26 to abut against the movable core 20, and a spring coefficient larger than that of the first spring 30, and the movable core 20 Since the second spring 32 urged in the direction away from the fixed core 14 is provided, when the excitation of the first and second coils 16 and 22 is turned off, the movable core 20, the external movable core 26, and The intermediate core 24 can be returned to the initial position. Further, when only the second coil 22 is excited, the gap of the first suction part 34 can be maintained.

  In addition, the movable core 20 includes a reduced diameter portion 20a whose outer diameter is reduced at one end thereof, and the other end 26b of the outer movable core 26 is configured to come into contact with the reduced diameter portion 20a. When only one coil 16 is excited, the gap between the second suction portions 36 can be maintained.

  In addition, since the intermediate core 24 and a part of the outer movable core 26 are configured to be used in common as part of the respective magnetic circuits generated by the first and second coils 16 and 22, the electromagnetic solenoid 10 can be The electromagnetic solenoid 10 can also be reduced in size when it is composed of the first and second coils 16 and 22.

  Next, an electromagnetic solenoid according to a second embodiment of the present invention will be described.

  FIG. 17 is an electric circuit diagram of the first and second coils of the electromagnetic solenoid according to the second embodiment. In the second embodiment, only the electric circuits of the first and second coils are different. In the electric circuit diagram, the same reference numerals are assigned to the same components as those in the first embodiment. Hereinafter, an electric circuit diagram of the first and second coils of the electromagnetic solenoid according to the second embodiment will be described.

  As shown in FIG. 17, the same power supply means as that of the first embodiment is provided on the upstream side of the first coil 16. A branch point is provided between the power supply means and the first coil 16, and the power supply means is connected to the second coil 22 via a third (NPN type) transistor 94. The downstream side of the first coil 16 is grounded via a fourth (NPN type) transistor 96, and a branch point is provided between the first coil 16 and the fourth transistor 96 to provide a fifth. The (NPN type) transistor 98 is connected to the second coil 22.

  In the electric circuit of FIG. 17, when an off signal is transmitted from the controller (not shown) to the bases of the third and fourth transistors 94 and 96 and an on signal is transmitted to the base of the fifth transistor 98, The two coils 16 and 22 are electrically energized in series. That is, the above-described series energization is performed.

  On the other hand, when an ON signal is transmitted to the bases of the third and fourth transistors 94 and 96 and an OFF signal is transmitted to the base of the fifth transistor 98, the first and second coils 16 and 22 are electrically Are energized in parallel (hereinafter referred to as “parallel energization”).

  Further, when an off signal is transmitted to the bases of the third and fifth transistors 94 and 98 and an on signal is transmitted to the base of the fourth transistor 96, only the first coil 16 is energized. That is, the above-described first coil one-side energization is performed.

  Further, when an off signal is transmitted to the bases of the fourth and fifth transistors 96 and 98 and an on signal is transmitted to the base of the third transistor 94, only the second coil 22 is energized. That is, the above-described second coil one-side energization is performed.

  The operations of the movable core 20, the external movable core 26, and the intermediate core when both the first and second coils 16, 22 are excited by parallel energization are the same as those of the first, second coils 16, 22 by series energization. This is the same as when both are excited. Accordingly, with respect to the displacement amount (stroke amount) of the movable core 20 in the case of parallel energization, the displacement amount of the movable core 20 in the gap of the second suction portion 36 and the displacement amount of the intermediate core 24 in the gap of the first suction portion 34. Is added in the same manner as in the case of series energization.

  Next, the suction force and suction response of the movable core 20 in the case of parallel energization will be described.

  The coil current I of each of the first and second coils 16 and 22 in parallel energization is twice the coil current I of the first and second coils in series energization. Therefore, from equations 1 and 2, the magnetomotive force M of each of the first and second coils 16 and 22 in parallel energization is twice the magnetomotive force M of the first and second coils 16 and 22 in series energization. The suction force in the first and second suction parts 34 and 36 is four times that in the case of series energization.

  In parallel energization, the coil inductances of the first and second coils 16 and 22 are L / 4, respectively. Therefore, from equations 3 and 4, the suction responsiveness of the movable core 20 in parallel energization is doubled compared to the case of series energization, and four times greater than the suction responsiveness of the movable core of a conventional electromagnetic solenoid. To do. FIG. 16C shows current rising curves of the first and second coils 16 and 22 when the electromagnetic solenoid 10 including the first and second coils 16 and 22 is energized in parallel.

  As described above, in the electromagnetic solenoid according to the second embodiment, the coil having the coil turn number N is divided into the first and second coils 16 and 22 having the coil turn number N / 2, respectively. , 22 are provided with first and second suction portions 34, 36 each having a gap of a distance X / 2 that moves the movable core 20 when excited, and the first coil 16 and the second coil 22 are electrically connected. Thus, since it is configured to energize in parallel (parallel energization), the suction force and suction response can be improved while securing the amount of displacement (stroke amount) of the movable core 20.

  As described above, in the electromagnetic solenoid according to the first and second embodiments of the present invention, the first coil (16) disposed around the fixed core (14) and the fixed core are adjacent to each other. A second coil (22) disposed around the movable core (20) provided, an intermediate core (24) movably disposed between the fixed core and the movable core, and the first coil A first suction part (34) comprising a gap formed between the fixed core and the intermediate core to move the intermediate core toward the fixed core when the coil is excited; A second suction portion (36) comprising a gap formed between the intermediate core and the movable core to move the movable core toward the intermediate core when the coil is excited; and the second Arranged outside the coil and one end While 26a) is bonded to the intermediate core, the other end (26b) is configured with an outer movable core to be brought into contact with the movable core (26).

  Furthermore, the first spring (30) that urges the other end of the external movable core to abut against the movable core, and a spring coefficient larger than that of the first spring, and the movable core And a second spring (32) for urging in the direction away from the fixed core.

  The movable core includes a reduced diameter portion (20a) whose outer diameter is reduced at one end thereof, and the other end (26b) of the outer movable core is configured to be in contact with the reduced diameter portion. did.

  In the above, the copper wire 62 connected to the terminal 60b in the first coil bobbin 50 is wound clockwise, and the copper wire 62 connected to the terminal 60d is wound counterclockwise in the second coil bobbin 52. In addition, although the terminal 60b and the terminal 60c are connected to be energized, the intermediate core 24 and a part of the outer movable core 26 have a magnetic flux in the same direction (inner to outer direction or inner to outer direction). In other words, that is, the winding direction of the copper wire and the terminal of the terminal are such that a part of the intermediate core 24 and the outer movable core 26 become a common magnetic path in the magnetic circuit generated by the first and second coils. If the connection is selected, the winding direction of the copper wire and the connection of the terminals are not limited to the above.

  In the above description, the electromagnetic solenoid for the fuel injection valve has been described. However, the present invention may be applied to an electromagnetic solenoid used for other purposes, for example, an electromagnetic solenoid used for an intake / exhaust valve opening / closing mechanism of an internal combustion engine. Good.

It is a longitudinal cross-sectional view of the electromagnetic solenoid which concerns on 1st Example of this invention. FIG. 2 is a perspective view of first and second coil bobbins of the electromagnetic solenoid shown in FIG. 1. It is a perspective view of the intermediate core of the electromagnetic solenoid shown in FIG. It is a perspective view of the external movable core of the electromagnetic solenoid shown in FIG. It is explanatory drawing which shows the assembly | attachment state of the 1st, 2nd coil, intermediate | middle core, and external movable core of the electromagnetic solenoid shown in FIG. It is explanatory drawing which shows typically the state by which the copper wire was wound around the 1st coil bobbin shown in FIG. It is explanatory drawing which shows typically the state by which the copper wire was wound around the 2nd coil bobbin shown in FIG. It is the elements on larger scale of the connection member shown in FIG. FIG. 9 is a partially enlarged view of the connecting member shown in FIG. 2 and the like as in FIG. 8. It is explanatory drawing which shows typically the magnetic flux direction of the magnetic circuit which generate | occur | produces when it supplies with electricity to the 1st, 2nd coil of the electromagnetic solenoid shown in FIG. It is an electric circuit diagram about the 1st, 2nd coil of the electromagnetic solenoid shown in FIG. It is a longitudinal cross-sectional view of an electromagnetic solenoid when it supplies with electricity to the 1st coil of the electromagnetic solenoid shown in FIG. It is a longitudinal cross-sectional view of an electromagnetic solenoid when it supplies with electricity to the 2nd coil of the electromagnetic solenoid shown in FIG. It is a longitudinal cross-sectional view of an electromagnetic solenoid when it supplies with electricity to the 1st, 2nd coil of the electromagnetic solenoid shown in FIG. It is a graph which shows the relationship between the attraction | suction force of the attraction | suction part of the electromagnetic solenoid shown in FIG. 1, and distance. It is a graph which shows the rising characteristic of the coil current of the electromagnetic solenoid shown in FIG. 1, ie, the suction responsiveness of a movable core. It is an electric circuit diagram about the 1st, 2nd coil of the electromagnetic solenoid which concerns on 2nd Example of this invention.

Explanation of symbols

10: electromagnetic solenoid, 14: fixed core, 16: first coil, 20: movable core, 20a: reduced diameter portion, 22: second coil, 24: intermediate core, 26: external movable core, 26a: one end, 26b: the other end, 30: the first spring, 32: the second spring, 34: the first suction part, 36: the second suction part

Claims (3)

a. A first coil disposed around a fixed core;
b. A second coil disposed around a movable core provided adjacent to the fixed core;
c. An intermediate core movably disposed between the fixed core and the movable core;
d. A first suction part comprising a gap formed between the fixed core and the intermediate core to move the intermediate core toward the fixed core when the first coil is excited;
e. A second suction part comprising a gap formed between the intermediate core and the movable core to move the movable core toward the intermediate core when the second coil is excited;
And f. An outer movable core disposed outside the second coil and having one end joined to the intermediate core and the other end abutted against the movable core;
An electromagnetic solenoid comprising: further,
g. A first spring that urges the other end of the external movable core to abut against the movable core;
And h. A second spring having a large spring coefficient compared to the first spring and biasing the movable core in a direction of separating the movable core from the fixed core;
The electromagnetic solenoid according to claim 1, further comprising:   3. The electromagnetic wave according to claim 2, wherein the movable core includes a reduced diameter portion having an outer diameter reduced at one end thereof, and the other end of the external movable core is in contact with the reduced diameter portion. solenoid.

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