Solenoid and switch

Abstract

Provided is a solenoid in which a solenoid coil-side end of a protruding portion has a step to allow for efficient linear motion of a movable core.　The solenoid comprises a solenoid coil (1), a movable core (2), and a fixed core (3). The movable core (2) has one end that linearly moves in a hollow portion of the solenoid coil (1), and includes on the other end side a protruding portion (2a) which is laterally symmetrically provided in a direction perpendicular to the linear motion direction and has a step on an end on the solenoid coil (1) side. The fixed core (3) encapsulates the solenoid coil (1) and includes a recess (3a) in which the protruding portion (2a) is fitted.

Description

Technical Field

[0001] The present disclosure relates to a solenoid and a switch using the solenoid.

Background Art

[0002] A solenoid is one of actuators composed of a fixed core, a movable core, and a solenoid coil that generates magnetic flux when an electric current flows through it. A protrusion perpendicular to the operating direction called a stopper is provided on the upper part of the movable core.

[0003] When an electric current flows through the solenoid coil, magnetic flux is generated, and an electromagnetic force acts due to the magnetic flux flowing through the air gap between the fixed core and the movable core. This electromagnetic force acts as a force (hereinafter referred to as an attractive force) that linearly moves the movable core toward the fixed core side, causing it to move and stop when the stopper contacts the fixed core.

[0004] Conventionally, a solenoid has been disclosed in which a convex portion is provided at the lower part of the movable core to reduce the air gap. (For example, see Patent Document 1)

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the above solenoid, the convex portion provided at the lower part of the movable core improves the attractive force by reducing the magnetic resistance. However, as the movable core linearly moves in the direction of the fixed core, the magnetic flux starts to flow in a direction perpendicular to the linear movement direction, and the ratio of the magnetic flux flowing in the linear movement direction decreases.

[0007] The present disclosure has been made to solve the above-described problems, and an object thereof is to obtain a solenoid that reduces the magnetic flux flowing in a direction perpendicular to the linear motion direction generated as the movable iron core moves linearly and increases the magnetic flux in the linear motion direction to improve the attractive force.

Means for Solving the Problems

[0008] The solenoid according to the present disclosure includes a solenoid coil that generates a magnetic flux by excitation due to energization and generates an electromagnetic force in which an attractive force acts in the axial direction within the hollow portion, and one end linearly moves within the hollow portion by the electromagnetic force, and on the other end side, there is a movable iron core having a protruding portion with steps provided symmetrically in a direction perpendicular to the linear motion direction, and a fixed iron core that encloses the solenoid coil and has a concave portion into which the protruding portion fits. , comprising a fixed core having a yoke extending in a direction opposite to the solenoid coil on the upper surface of the fixed core, or the protrusion having a yoke extending in the linear motion direction at the end, and the yoke being provided so as to be magnetically saturated when the movable core is linearly moving. Also, a solenoid coil that generates magnetic flux by excitation due to energization and generates an electromagnetic force with an attractive force acting in the axial direction within the hollow portion, a movable core having one end linearly moving within the hollow portion by the electromagnetic force and having a protrusion with stepped ends provided symmetrically in a direction perpendicular to the linear motion direction on the other end side of the solenoid coil side, and a fixed core that encloses the solenoid coil and has a recess into which the protrusion fits. The fixed core has a yoke extending in a direction opposite to the solenoid coil on the upper surface of the fixed core, or the protrusion has a yoke extending in the linear motion direction at the end, and the yoke is provided so as to be magnetically saturated when the height of the lowermost surface of the protrusion and the upper surface of the fixed core coincide. Also, a solenoid coil that generates magnetic flux by excitation due to energization and generates an electromagnetic force with an attractive force acting in the axial direction within the hollow portion, a movable core having one end linearly moving within the hollow portion by the electromagnetic force and having a protrusion with stepped ends provided symmetrically in a direction perpendicular to the linear motion direction on the other end side of the solenoid coil side, and a fixed core that encloses the solenoid coil and has a recess into which the protrusion fits. The fixed core has a yoke extending in a direction opposite to the solenoid coil on the upper surface of the fixed core, and the yoke is provided so as to be magnetically saturated when the movable core linearly moves and the height of the upper surface of the yoke and the upper surface of the protrusion coincide.

Effect of the Invention

[0009] According to the solenoid of the present disclosure, by providing steps at the end of the protruding portion of the movable iron core, it has the effect of being able to efficiently perform the linear motion of the movable iron core.

Brief Description of the Drawings

[0010]

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Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments will be described in detail with reference to the drawings. Note that the embodiments described below are examples. Also, each embodiment can be executed in appropriate combination.

[0012] Embodiment 1. FIG. 1 is a perspective view of a solenoid according to Embodiment 1 of the present disclosure. FIG. 2 is a view showing the solenoid in the initial position according to Embodiment 1 of the present disclosure. FIG. 3 is a view showing the solenoid in the intermediate position according to Embodiment 1 of the present disclosure. FIG. 4 is a view showing the solenoid in the adsorption position according to Embodiment 1 of the present disclosure. FIG. 5 is an enlarged view corresponding to part E of FIG. 4 according to Embodiment 1 of the present disclosure.

[0013] The solenoid shown in FIGS. 1 and 2 includes a solenoid coil 1 that generates an electromagnetic force by excitation due to energization, a movable iron core 2 whose one end moves linearly inside the hollow portion of the solenoid coil 1, and a protruding portion 2a provided symmetrically on the other end side in a direction perpendicular to the linear movement direction, and a fixed iron core 3 having a first concave portion 3b into which a convex portion fits and a second concave portion 3a into which the protruding portion 2a fits.

[0014] The X-axis shown in FIG. 1 is the linear movement direction of the movable iron core 2, the Y-axis is the direction in which the protruding portion 2a perpendicular to the linear movement direction of the movable iron core 2 is provided, and the Z-axis is the depth direction of the solenoid according to the present embodiment. Although each axis is shown in the following figures, the description is omitted because it is the same.

[0015] The solenoid coil 1 is wrapped around the fixed iron core 3 and is provided such that the movable iron core 2 moves linearly inside the hollow portion corresponding to the air core. By excitation due to energization, a magnetic flux is generated to generate an electromagnetic force. Inside the hollow portion, an attractive force Fx that linearly moves the movable iron core 2 in the axial direction acts.

[0016] The movable iron core 2 is provided with a convex portion 2b at one end on the solenoid coil 1 side, and is provided with protruding portions 2a that are symmetrically provided in the left - right direction in a direction perpendicular to the linear motion direction on the other end side. The movable iron core 2 is linearly moved within the hollow portion of the solenoid coil 1 by the attracting force Fx, and is provided so as to stop when the protruding portion 2a fits into the second concave portion 3a of the fixed iron core 3. Further, the convex portion 2b provided at one end of the movable iron core 2 on the solenoid coil 1 side fits into the first concave portion 3b provided on the fixed iron core 3 and the movable iron core stops.

[0017] The protruding portion 2a has a stepped shape with one or more steps where the end on the solenoid coil 1 side is stepped. In FIG. 1, an example with one step of the protruding portion 2a is shown, but a plurality of steps may be provided. An example with a plurality of steps will be described in the following embodiments.

[0018] The fixed iron core 3 encloses the solenoid coil 1, and has a second concave portion 3a on the upper surface into which the protruding portion 2a fits when the linear motion of the movable iron core 2 stops. At the bottom inside the fixed iron core 3, a first concave portion 3b into which the convex portion 2b provided at one end of the movable iron core 2 fits when the linear motion of the movable iron core 2 stops is provided.

[0019] In the present disclosure, the movable iron core 2 provided with the convex portion 2b at one end is illustrated and described, but the present disclosure is not limited to this shape, and the effects described in the present disclosure can also be obtained in a movable iron core 2 without the convex portion 2b. Similarly, although the first concave portion 3b provided on the fixed iron core 3 is illustrated and described, the present disclosure is not limited to this shape, and the effects described in the present disclosure can also be obtained in a fixed iron core 3 without the first concave portion 3b.

[0020] Next, the operation will be described with reference to FIGS. 2 to 4. The arrows in the figures indicate magnetic flux, the white arrows indicate the attracting force Fx, and it is assumed that the thickness of the arrows represents the magnitude. Also, in the following embodiments, the magnetic flux and the attracting force Fx will be similarly illustrated and the description will be omitted.

[0021] FIG. 2 is a diagram showing the solenoid in the initial position. When the solenoid coil 1 is energized, an electric current flows through the solenoid coil 1, generating a magnetic flux that forms a magnetic path. When the magnetic flux flows through the space gap between the movable iron core 2 and the fixed iron core 3, an attractive force Fx is generated, and the movable iron core 2 moves linearly in the linear motion direction, that is, the X-axis direction, due to the attractive force Fx.

[0022] FIG. 3 is a diagram showing the solenoid in the intermediate position. When the movable iron core 2 moves linearly in the X-axis direction due to the attractive force Fx and the timing when the lowermost surface of the protruding portion 2a starts to fit into the second recess 3a provided in the fixed iron core 3, that is, when the height of the lowermost surface of the protruding portion 2a coincides with the upper surface of the fixed iron core 3, the magnetic flux (oblique magnetic flux) flowing from the fixed iron core 3 to the protruding portion 2a increases.

[0023] The component of this oblique magnetic flux in the X-axis direction becomes a part of the attractive force Fx that linearly moves the movable iron core 2 in the X-axis direction. In this way, it is possible to efficiently convert the magnetic flux obtained from the solenoid coil 1 into the attractive force Fx.

[0024] FIG. 4 is a diagram showing the solenoid in the adsorption position. Adsorption refers to the state where the linear motion of the movable iron core 2 stops. The movable iron core 2 moves linearly due to the attractive force Fx and stops when the convex portion 2b fits into the first recess 3b and the protruding portion 2a fits into the second recess 3a, respectively.

[0025] From the above, the solenoid according to Embodiment 1 includes a movable iron core 2 having a convex portion 2b at one end and a stepped protruding portion 2a with an end on the side of the solenoid coil 1 provided symmetrically in the direction perpendicular to the linear motion direction on the other end side. By this, an oblique magnetic flux flowing from the fixed iron core 3 to the protruding portion 2a is generated. As a result, the component of the oblique magnetic flux in the linear motion direction can be made the attractive force Fx, and the effect that the movable iron core 2 can move linearly efficiently is obtained.

[0026] In addition, in the present embodiment, the fixed core 3 shown in FIGS. 1 to 4 is illustrated. However, the same effects can be obtained even with a fixed core 3 having a different shape. A specific shape of the fixed core 3 will be described with reference to FIG. 5. FIG. 5 is an enlarged view corresponding to part E of FIG. 4. Although the fixed core 3 having the protruding portion 3c with hatching different from others is taken as an example for explanation, the same effects can be obtained even with a fixed core 3 without the protruding portion 3c. In the following embodiments, the fixed core 31 without the protruding portion 3c will be illustrated and described.

[0027] Embodiment 2. In Embodiment 1, a solenoid including a movable core 2 having a convex portion 2b at one end and a stepped protruding portion 2a with the end portions on the solenoid coil 1 side provided symmetrically in the direction perpendicular to the linear motion direction on the other end side was shown. In Embodiment 2, a fixed core 31 without the protruding portion 3c of the fixed core 3 is configured, and a yoke 4 is newly provided at the end of the upper surface of the fixed core 31. A specific description will be given later with reference to FIG. 6. The other configurations are the same as those in Embodiment 1. The same numbers are assigned to the same configurations as those in Embodiment 1, and the description thereof will be omitted.

[0028] The present embodiment will be described with reference to FIGS. 6 to 14. FIG. 6 is a perspective view of the solenoid according to the present embodiment. FIG. 7 is a diagram defining the relationship of lengths according to the present embodiment. FIG. 8 is a diagram showing the solenoid at the initial position according to the present embodiment. FIG. 9 is an enlarged view corresponding to part P of FIG. 8 showing the relationship between the magnetic flux flowing through the air gap and the attractive force according to the present embodiment. FIG. 10 is a diagram showing the solenoid at an intermediate position according to the present embodiment. FIG. 11 is a diagram showing the solenoid at an intermediate position according to the present embodiment. FIG. 12 is a diagram showing the solenoid at the adsorption position according to the present embodiment. FIG. 13 is a diagram comparing the attractive forces of the solenoids according to the comparative form and the present embodiment.

[0029] As shown in FIG. 6, the solenoid according to the present embodiment includes a fixed core 31 that does not have the protrusion 3c of the fixed core 3, and a yoke 4 is newly provided at the end of the upper surface of the fixed core 31. The yoke 4 is provided to extend in a direction opposite to the solenoid coil 1 at the end of the upper surface of the fixed core 31. Further, the cross-sectional area S of the yoke 4 is set such that the yoke 4 is magnetically saturated when the height of the lowermost surface of the protrusion 2a coincides with the height of the upper surface of the fixed core 31. In order to magnetically saturate the yoke 4 at a desired timing, the cross-sectional area S of the yoke 4 shown in FIG. 6 may be set by adjusting the thickness and width of the yoke 4.

[0030] FIG. 7 is a diagram defining the relationship of lengths. In FIG. 7, the height of the yoke 4 is defined as L1, the depth of the first recess 3b provided at the bottom of the fixed core 31 is defined as L2, and the height of the lowermost surface of the protrusion 2a and the upper surface of the fixed core 31 is defined as L3. In the present embodiment, the height of the yoke 4 is set to be higher than the depth of the first recess 3b provided at the bottom of the fixed core 31. That is, in the present embodiment, the height of the yoke 4 is set such that L1≧L2, and the cross-sectional area S of the yoke 4 is determined such that the yoke 4 is magnetically saturated when L3 = 0.

[0031] Next, the operation will be described with reference to FIGS. 8 to 12. FIG. 8 is a diagram showing the solenoid in the initial position. In the present embodiment, the initial position is a state where the lowermost surface of the protrusion 2a is higher than the upper surface of the fixed core 31. When a current is passed through the solenoid coil 1 in the initial position shown in FIG. 8, a magnetic path is formed by the yoke 4, the protrusion 2a, the movable core 2, the convex portion 2b, and the fixed core 31. A suction force Fx that linearly moves the movable core 2 in the X-axis direction is generated by the magnetic flux flowing through the space gap between the movable core 2 and the fixed core 31. Specifically, the description will be made with reference to FIG. 9.

[0032] Figure 9 is an enlarged view corresponding to the P part of Figure 8. As shown in Figure 9, an attractive force Fx is generated by the magnetic flux Φx flowing in the X-axis direction among the magnetic fluxes flowing through the space gap between the yoke 4 and the protruding part 2a, and the movable iron core 2 is attracted in the X-axis direction. Further, as the space gap between the movable iron core 2 and the fixed iron core 31 decreases due to the linear movement of the movable iron core 2, the magnetic resistance decreases, so the magnetic flux obtained from the solenoid coil 1 increases.

[0033] Figure 10 is a diagram showing the solenoid at position A. Position A refers to the time when the heights of the upper surface of the protruding part 2a and the upper surface of the yoke 4 of the solenoid according to the present embodiment coincide. As shown in Figure 10 at position A, the ratio of the magnetic flux flowing through the space gap in the Y-axis direction increases, and the ratio of the magnetic flux flowing in the X-axis direction decreases. Therefore, the attractive force Fx decreases as the magnetic flux flowing in the X-axis direction decreases.

[0034] Figure 11 is a diagram showing the solenoid at position B. Position B refers to the time when the heights of the lowermost surface of the protruding part 2a and the upper surface of the fixed iron core 31 of the solenoid according to the present embodiment coincide. The magnetically saturated yoke 4 is shown with different hatching from the movable iron core 2 and the fixed iron core 31. As shown in Figure 11, when the heights of the lowermost surface of the protruding part 2a and the upper surface of the fixed iron core 31 coincide, that is, when L3 = 0, the cross-sectional area S of the yoke 4 is set so that the yoke 4 is magnetically saturated. Thereby, it is possible to suppress the magnetic flux flowing from the fixed iron core 31 to the yoke 4 from exceeding a certain amount, and increase the magnetic flux flowing between the fixed iron core 31 with a small magnetic resistance and the protruding part 2a. That is, by increasing the ratio of the space gap flowing in the X-axis direction, the magnetic flux obtained from the solenoid coil 1 can be made into the attractive force Fx that linearly moves the movable iron core 2 more efficiently.

[0035] Figure 12 is a diagram showing the solenoid at the adsorption position. The movable iron core 2 linearly moves due to the attractive force Fx, and stops when the convex part 2b fits and abuts against the first concave part 3b and the protruding part 2a fits and abuts against the second concave part 3a, respectively.

[0036] In this embodiment, when the height of the lowermost surface of the protruding portion 2a coincides with the upper surface of the fixed core 31, that is, when L3 = 0, the cross-sectional area S of the yoke 4 is designed and the height is set so that the yoke 4 is magnetically saturated. Here, with reference to FIG. 13, a comparison of the attracting force Fx between this embodiment and a comparative form will be made. The comparative form is a solenoid according to this embodiment in which the yoke 4 is not magnetically saturated at position B. FIG. 13 is a diagram comparing the attracting force Fx between the solenoid according to this embodiment and the solenoid according to the comparative form.

[0037] As shown in FIG. 13, it can be seen that in the solenoid according to this embodiment, when the yoke 4 is magnetically saturated at position B, the magnetic flux flowing from the fixed core 31 to the protruding portion 2a is increased compared to the solenoid according to the comparative form, and the attracting force Fx is improved. From this result, it can be said that the solenoid according to this embodiment can make the magnetic flux obtained from the solenoid coil 1 contribute efficiently to the attracting force Fx for the linear motion of the movable core 2.

[0038] As described above, the solenoid according to this embodiment is formed such that the yoke 4 is magnetically saturated when the height of the lowermost surface of the protruding portion 2a coincides with the upper surface of the fixed core 31, that is, when L3 = 0, so that the magnetic flux in the Y-axis direction that does not contribute to the attracting force Fx flowing from the yoke 4 to the protruding portion 2a can be suppressed. Also, when the height of the lowermost surface of the protruding portion 2a coincides with the upper surface of the fixed core 31, that is, when L3 = 0, by setting the cross-sectional area S of the yoke 4 so that the yoke 4 is magnetically saturated, the magnetic flux flowing from the fixed core 31 to the protruding portion 2a can be increased. In this way, a solenoid that can efficiently move the movable core 2 linearly is obtained by increasing the magnetic flux that contributes to the attracting force Fx and suppressing the magnetic flux that does not contribute to the attracting force Fx.

[0039] Also, in this embodiment, a solenoid in which the yoke 4 is magnetically saturated when the height of the bottom surface of the protruding portion 2a coincides with the upper surface of the fixed core 31, that is, when L3 = 0, is shown. However, the timing of magnetic saturation is not limited to when the height of the bottom surface of the protruding portion 2a coincides with the upper surface of the fixed core 31, that is, when L3 = 0. For example, the above effect can also be obtained even if the yoke 4 is magnetically saturated at a timing before and after the height of the bottom surface of the protruding portion 2a coincides with the upper surface of the fixed core 31 (L3 ≈ 0).

[0040] Also, in this embodiment, the fixed core 31 without the protruding portion 3c is illustrated and described. However, the same effect can be obtained by using the fixed core 3 having the protruding portion 3c illustrated in Embodiment 1.

[0041] Embodiment 3. In this embodiment, the height of the yoke 4 is set lower than the depth of the first recess 3b (L1 < L2). Further, the cross-sectional area S of the yoke 4 is determined so that the yoke 4 is magnetically saturated when the height of the upper surface of the protruding portion 2a coincides with the upper surface of the yoke 4, and it is provided at the end of the upper surface of the fixed core 31. Other configurations are the same as those in Embodiment 2, and the same configurations as those in Embodiment 2 are given the same numbers, and the description is omitted.

[0042] This embodiment will be described with reference to FIGS. 14 to 16. FIG. 14 is a diagram showing the solenoid in the initial position according to this embodiment. FIG. 15 is a diagram showing the solenoid in the intermediate position according to this embodiment. FIG. 16 is a diagram comparing the attracting forces of the solenoids according to Embodiment 2 and Embodiment 3.

[0043] As shown in Fig. 14, in the solenoid according to the present embodiment, the yoke 4 is provided such that the height of the yoke 4 is lower than the depth of the first recess 3b. The initial position is set such that the protruding portion 2a of the movable iron core 2 is higher than the upper surface of the yoke 4. When a current is passed through the solenoid coil 1 in the initial position, a magnetic path is formed by the yoke 4, the protruding portion 2a, the movable iron core 2, the convex portion 2b, and the fixed iron core 31. Then, an attractive force Fx is generated by the magnetic flux flowing through the space gap between the movable iron core 2 and the fixed iron core 31, and the movable iron core 2 moves linearly in the X-axis direction.

[0044] Fig. 15 shows the solenoid at the timing when the yoke 4 is magnetically saturated. The state of the solenoid according to the present embodiment when the height of the upper surface of the protruding portion 2a shown in Fig. 15 coincides with the upper surface of the yoke 4 is defined as position C. In Fig. 15, the magnetically saturated yoke 4 is shown with a different hatching from the movable iron core 2 and the fixed iron core 31. By magnetically saturating the yoke 4 when the height of the upper surface of the protruding portion 2a coincides with the height of the yoke 4, it is possible to suppress the magnetic flux flowing from the fixed iron core 31 to the yoke 4 from exceeding a certain amount. In addition, the magnetic flux flowing from the fixed iron core 31 with a small magnetic resistance to the protruding portion 2a increases. That is, by suppressing the magnetic flux that does not contribute to the attractive force Fx and increasing the magnetic flux that contributes to the attractive force Fx, the magnetic flux obtained from the solenoid coil 1 can be efficiently converted into the attractive force Fx that linearly moves the movable iron core 2.

[0045] Here, Fig. 16 is used to compare the attractive force Fx between Embodiment 2 and the present embodiment. Fig. 16 is a diagram comparing the attractive force Fx of the solenoid according to Embodiment 2 and the solenoid according to the present embodiment.

[0046] In Embodiment 2 and the present embodiment, the magnitude relationship between the height of the yoke 4 and the depth of the first recess 3b is different. From Fig. 16, it can be seen that the solenoid according to the present embodiment has an improved attractive force Fx at position C compared to the solenoid according to Embodiment 2. That is, it can be said that the space gap between the movable iron core 2 and the fixed iron core 31 is reduced, and the attractive force Fx can be improved even when the distance between the movable iron core 2 and the fixed iron core 31 is small.

[0047] As described above, for the solenoid according to this embodiment, the cross-sectional area S of the yoke 4 is set such that the height of the yoke 4 is lower than the depth of the first concave portion 3b. Thereby, the attractive force Fx can be improved at a position where the distance between the movable iron core 2 and the fixed iron core 31 is short, and even when set to the output characteristics required for the solenoid, the attractive force Fx can be improved at a desired timing.

[0048] Also, in this embodiment, a solenoid in which the yoke 4 is magnetically saturated when the height of the upper surface of the protruding portion 2a coincides with the height of the upper surface of the yoke 4 is shown. However, for example, the above-described effect can also be obtained even if the yoke 4 is magnetically saturated at a timing before and after the height of the upper surface of the protruding portion 2a coincides with the height of the upper surface of the yoke 4.

[0049] Also, in this embodiment, the fixed iron core 31 having no protruding portion 3c is illustrated and described. However, the same effect can be obtained even when the fixed iron core 3 having the protruding portion 3c illustrated in the first embodiment is used.

[0050] In the second and third embodiments, an example of a solenoid that magnetically saturates the yoke 4 has been described. However, the timing of magnetic saturation is not limited to the timing of the second and third embodiments, and may be set such that the yoke 4 is magnetically saturated when the movable iron core 2 moves, that is, until the movable iron core 2 linearly moves from the initial position to the adsorption position. In this way, by setting the yoke 4 to be magnetically saturated during the movement of the movable iron core 2, the magnetic flux flowing through the yoke 4 via the protruding portion 2a can be suppressed, and the attractive force Fx can be adjusted.

[0051] Also, by setting the yoke 4 to be magnetically saturated after the Y-axis component of the magnetic flux (oblique magnetic flux) generated between the fixed iron core 3 and the protruding portion 2a becomes larger than the X-axis component of the magnetic flux generated between the yoke 4 and the tip portion of the protruding portion 2a, the magnetic flux in the X-axis direction can be increased, and the attractive force Fx can be improved.

[0052] Embodiment 4. In the previous embodiment, a solenoid provided with a yoke 4 at the end of the upper surface of the fixed core 31 was shown. In this embodiment, a solenoid provided with a yoke 41 at the end of the protruding portion 2a is shown. Specifically, when the height of the upper surface of the fixed core 31 and the lowermost surface of the protruding portion 2a coincide, the cross-sectional area S of the yoke 41 is set so that the yoke 41 extending toward the solenoid coil 1 side at the end of the protruding portion 2a is magnetically saturated. Other configurations are the same as those in Embodiment 3. The same configurations as those in Embodiment 3 are given the same numbers and the description thereof is omitted.

[0053] This embodiment will be described with reference to FIGS. 17 and 18. FIG. 17 is a diagram showing the solenoid in the initial position according to this embodiment. FIG. 18 is a diagram showing the solenoid in which the yoke is magnetically saturated according to this embodiment.

[0054] As shown in FIG. 17, for the solenoid according to this embodiment, the cross-sectional area S of the yoke 41 is set so that the yoke 41 extending toward the solenoid coil 1 side is magnetically saturated when the height of the lowermost surface of the protruding portion 2a and the upper surface of the fixed core 31 coincide. The state in which the lowermost surface of the protruding portion 2a is at a position higher than the upper surface of the fixed core 31 is taken as the initial position. When a current is passed through the solenoid coil 1 in the initial position, a magnetic path is formed by the yoke 41, the protruding portion 2a, the movable core 2, the convex portion 2b, and the fixed core 31. Then, an attractive force Fx is generated by the magnetic flux flowing through the space gap between the movable core 2 and the fixed core 31, and the movable core 2 moves linearly in the X-axis direction.

[0055] FIG. 18 illustrates a solenoid at the timing when the yoke 41 reaches magnetic saturation, i.e., the timing when the height of the upper surface of the fixed core 31 coincides with the bottom surface of the protruding portion 2a. In FIG. 18, the magnetically saturated yoke 41 is shown with a different hatching from the movable core 2 and the fixed core 31. By magnetically saturating the yoke 41 when the height of the bottom surface of the protruding portion 2a coincides with the upper surface of the fixed core 31, it is possible to suppress the magnetic flux flowing from the fixed core 31 to the yoke 4 from exceeding a certain amount. Also, the magnetic flux flowing from the fixed core 31 with a small magnetic resistance to the protruding portion 2a increases. That is, by suppressing the magnetic flux that does not contribute to the attractive force Fx and increasing the magnetic flux that contributes to the attractive force Fx, the magnetic flux obtained from the solenoid coil 1 can be efficiently converted into the attractive force Fx that linearly moves the movable core 2.

[0056] As described above, in the present embodiment, a solenoid is shown in which the cross-sectional area S of the yoke 41 is set to be magnetically saturated when the height of the upper surface of the fixed core 31 coincides with the bottom surface of the protruding portion 2a of the yoke 41 that extends toward the solenoid coil 1 side of the protruding portion 2a. Thereby, even when the position where the yoke 41 is attached is changed, the attractive force Fx can be improved and the movable core 2 can be linearly moved efficiently.

[0057] Also, in the present embodiment, a solenoid is shown in which the yoke 41 is magnetically saturated when the height of the bottom surface of the protruding portion 2a coincides with the upper surface of the fixed core 31. However, for example, the above-described effects can also be obtained by magnetically saturating the yoke 41 at a timing before and after the height of the bottom surface of the protruding portion 2a coincides with the upper surface of the fixed core 31.

[0058] Also, in the present embodiment, the fixed core 31 without the protruding portion 3c is illustrated and described. However, the same effects can be obtained by using the fixed core 3 having the protruding portion 3c illustrated in the first embodiment.

[0059] Embodiment 5. In the embodiments described so far, a solenoid having a stepped protruding portion 2a with a stepped end on the solenoid coil 1 side was shown. In this embodiment, a solenoid having a protruding portion 2a with a plurality of steps is shown. Also, a plurality of yokes with different cross-sectional areas are provided, with the cross-sectional area set so that the yoke is magnetically saturated according to the number of steps of the protruding portion 2a. Other configurations are the same as those in Embodiment 2, and the same configurations as those in Embodiment 2 are given the same numbers and the description is omitted.

[0060] This embodiment will be described with reference to FIGS. 19 to 22. FIG. 19 is a perspective view of the solenoid according to this embodiment. FIG. 20 is a view showing the solenoid in the initial position according to this embodiment. FIG. 21 is a view showing the solenoid in which the yoke 4a is magnetically saturated according to this embodiment. FIG. 22 is a view showing the solenoid in which the yoke 4b is magnetically saturated according to this embodiment.

[0061] As shown in FIG. 19, the protruding portion 2a of the movable iron core 2 has a stepped shape with a plurality of steps at the end. The yoke extending upward provided at the end of the upper surface of the fixed iron core 31 has a cross-sectional area set so that the yoke is magnetically saturated step by step according to the protruding portion 2a. In FIG. 19, the cross-sectional areas of the yoke 4a and the yoke 4b are set to S and Sc (Sc > S), respectively, and the yoke 4b and the yoke 4a are provided in order from the upper surface of the fixed iron core 31. Also, in FIG. 19, as an example, a protruding portion 2a with two steps (four in total including left and right) is illustrated, but the number of steps may be three or more, and a plurality of yokes with different cross-sectional areas may be provided accordingly.

[0062] Next, the operation will be described. FIG. 20 is a view showing the solenoid in the initial position. The state where the lowermost surface of the protruding portion 2a is higher than the upper surface of the fixed iron core 31 is defined as the initial position. When a current is passed through the solenoid coil 1 in the initial position, a magnetic path is formed by the yoke 4b, the yoke 4a, the protruding portion 2a, the movable iron core 2, the convex portion, and the fixed iron core 31. Then, an attractive force Fx is generated by the magnetic flux flowing through the air gap between the movable iron core 2 and the fixed iron core 31, and the movable iron core 2 moves linearly in the X-axis direction.

[0063] As shown in FIG. 21, when the height of the upper surface of the yoke 4b coincides with the height of the lower surface of the protrusion 2a closest to the fixed core 31, the yoke 4a becomes magnetically saturated. In FIG. 21, the magnetically saturated yoke 4a is shown with a different hatching from the movable core 2, the fixed core 31, and the yoke 4b. By magnetically saturating the yoke 4a, it is possible to suppress the magnetic flux flowing from the yoke 4b to the yoke 4a from exceeding a certain amount. In addition, the magnetic flux flowing from the yoke 4b with a small magnetic resistance to the protrusion 2a increases. That is, by suppressing the magnetic flux that does not contribute to the attractive force Fx and increasing the magnetic flux that contributes to the attractive force Fx, the magnetic flux obtained from the solenoid coil 1 can be efficiently converted into the attractive force Fx that linearly moves the movable core 2.

[0064] Furthermore, as shown in FIG. 22, when the height of the upper surface of the fixed core 31 coincides with the height of the lowermost surface of the protrusion 2a, the yoke 4b becomes magnetically saturated. In FIG. 22, the magnetically saturated yokes 4a and 4b are shown with a different hatching from the movable core 2 and the fixed core 31. By magnetically saturating the yoke 4b, it is possible to suppress the magnetic flux flowing from the fixed core 31 to the yoke 4b from exceeding a certain amount. In addition, the magnetic flux flowing from the fixed core 31 with a small magnetic resistance to the protrusion 2a increases. As a result, the ratio of the magnetic flux flowing in the X-axis direction can be increased, and the magnetic flux obtained from the solenoid coil 1 can be efficiently converted into the attractive force Fx that linearly moves the movable core 2.

[0065] As described above, the present embodiment has a plurality of steps and shows a solenoid having a stepped protrusion 2a with an end on the solenoid coil 1 side being stepped. In addition, the cross-sectional areas S and Sc of the yokes 4a and 4b are set so as to provide a plurality of stages of timings at which the yokes 4a and 4b become magnetically saturated according to the number of steps of the protrusion 2a. As a result, the attractive force Fx can be improved in a plurality of stages, and a solenoid that linearly moves the movable core 2 efficiently can be obtained.

[0066] In this embodiment, a solenoid is exemplified in which the yokes 4a and 4b are magnetically saturated when the height of the upper surface of the yoke 4b coincides with the height of the lower surface of the protruding portion 2a closest to the fixed core 31 and when the height of the upper surface of the fixed core 31 coincides with the height of the lowermost surface of the protruding portion 2a. However, the timing of magnetic saturation is not limited to this. For example, the above-described effects can be obtained even if the yoke 4a is magnetically saturated at a timing before or after the height of the upper surface of the yoke 4b coincides with the height of the lower surface of the protruding portion 2a closest to the fixed core 31. Similarly, the above-described effects can be obtained even if the yoke 4b is magnetically saturated at a timing before or after the height of the upper surface of the fixed core 31 coincides with the height of the lowermost surface of the protruding portion 2a.

[0067] In this embodiment, the fixed core 31 without the protruding portion 3c has been illustrated and described. However, the same effects can be obtained by using the fixed core 3 having the protruding portion 3c illustrated in Embodiment 1. Further, the yokes 4a and 4b may be provided on the protruding portion 2a as in the solenoid according to Embodiment 4.

[0068] Embodiment 6. This embodiment shows an example in which the solenoid 5 according to the embodiments so far is applied to a switch. FIG. 23 is a diagram showing an application example of the solenoid to a switch.

[0069] As shown in FIG. 23, the switch 6 has a contact point 63 at which a fixed contact of the fixed contactor and a movable contact of the movable contactor make contact and separate, and a solenoid 5 connected to the movable contactor and operating the movable contactor.

[0070] The operation will be described. By passing a current through the solenoid 5 and linearly moving the movable core 2, the lever 61 is operated. By closing the contact point 63 using the linear movement of the movable core 2, the energized state is entered. Thereby, it becomes possible to operate the switch 6 by an electric signal. By applying the solenoid 5 according to Embodiments 1 to 5 to the switch according to this embodiment, it is possible to obtain the suction force Fx required for the switch-on operation from a small current.

[0071] As described above, in this embodiment, a switch applying the solenoid 5 according to Embodiments 1 to 5 is shown. In this way, the energization operation of the switch can be performed from a small current. In this embodiment, an application example to a switch is shown as an example, but the present invention is not limited thereto.

Description of Reference Numerals

[0072] 1 Solenoid coil, 2 Movable iron core, 2a Protrusion, 2b Convex portion, 3, 31 Fixed iron core, 3a Second recess, 3b First recess, 3c Protrusion, 4, 41, 4a, 4b Yoke, 5 Solenoid, 6 Switch, 61 Lever, 62 Fulcrum, 63 Contact, 64 Contact pressure spring, 65 Main circuit section, Fx Attractive force

Claims

1. A solenoid coil that generates magnetic flux by energization and excitation and generates an electromagnetic force with an attractive force acting in the axial direction within a hollow portion, a movable iron core that is linearly moved at one end within the hollow portion by the electromagnetic force and has a protruding portion with steps provided symmetrically in a direction perpendicular to the linear movement direction on the other end side, at the end on the solenoid coil side, a fixed iron core that encloses the solenoid coil and has a recess into which the protruding portion fits, comprising: the fixed iron core has a yoke extending in a direction opposite to the solenoid coil on the upper surface of the fixed iron core, or the protruding portion has a yoke extending in the linear movement direction at the end, the yoke is provided so as to be magnetically saturated when the movable iron core is linearly moving, characterized by a solenoid.

2. A solenoid coil that generates magnetic flux by energization and excitation and generates an electromagnetic force with an attractive force acting in the axial direction within a hollow portion, a movable iron core that is linearly moved at one end within the hollow portion by the electromagnetic force and has a protruding portion with steps provided symmetrically in a direction perpendicular to the linear movement direction on the other end side, at the end on the solenoid coil side, a fixed iron core that encloses the solenoid coil and has a recess into which the protruding portion fits, comprising: the fixed iron core has a yoke extending in a direction opposite to the solenoid coil on the upper surface of the fixed iron core, or the protruding portion has a yoke extending in the linear movement direction at the end, the yoke is provided so as to be magnetically saturated when the height of the lowermost surface of the protruding portion coincides with the upper surface of the fixed iron core, characterized by a solenoid.

3. A solenoid coil that generates magnetic flux by energization and excitation and generates an electromagnetic force with an attractive force acting in the axial direction within a hollow portion, a movable iron core that is linearly moved at one end within the hollow portion by the electromagnetic force and has a protruding portion with steps provided symmetrically in a direction perpendicular to the linear movement direction on the other end side, at the end on the solenoid coil side, a fixed iron core that encloses the solenoid coil and has a recess into which the protruding portion fits, comprising: the fixed iron core has a yoke extending in a direction opposite to the solenoid coil on the upper surface of the fixed iron core, the yoke is provided so as to be magnetically saturated when the movable iron core is linearly moving and the height of the upper surface of the yoke coincides with the upper surface of the protruding portion, characterized by a solenoid.

4. A fixed contactor having a fixed contact, a movable contactor having a movable contact that contacts and separates from the fixed contact The solenoid according to any one of claims 1 to 3, which is connected to the movable contact and operates the movable contact, and a switch comprising the same.

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