WO2002027226A1

WO2002027226A1 - Linear solenoid and solenoid valve

Info

Publication number: WO2002027226A1
Application number: PCT/JP2001/008632
Authority: WO
Inventors: Ichiro Hirata; Norio Uemura; Yoshinari Kasagi
Original assignee: Nok Corporation
Priority date: 2000-09-29
Filing date: 2001-10-01
Publication date: 2002-04-04
Also published as: AU2001292324A1; JP2005098310A

Abstract

A linear solenoid exhibiting linear characteristics and having an increased attractive force, a small size, and an excellent reliability. The solenoid comprises an annular attracting section (22) and a plunger (1). The annular attracting section (22) has an outer taper portion (22a) the diameter of which decreases toward the plunger (1) on its outer periphery and an inner taper portion (22b) the diameter of which increases toward the plunger (1) on its inner periphery. The plunger (1) has an attraction taper portion (1a) on the outer periphery near the center post (2). The surface of the attraction taper portion (1a) inclines similarly to the inner taper portion (22b) of the annular attraction section (22). The magnetic flux M1 passes between the inner taper portion (22b) and the attraction taper portion (1a). Consequently, the axial component of the magnetic force M1 increases, and therefore a strong attractive force F is produced. A solenoid valve is also disclosed.

Description

Description Rear solenoid and solenoid valve

Technical field

The present invention relates to a linear solenoid and a solenoid valve suitably used for various fluid pressure controls and the like, and is applied to, for example, a linear solenoid valve. Background art

Conventionally, as this type of solenoid valve, for example, there is one shown in FIG. FIG. 7 is a schematic configuration sectional view of a solenoid valve according to the prior art.

The solenoid valve 200 is composed of a solenoid part 200 A and a valve part 200 B which are linear solenoids.

Here, the vanoleb section 200B is a spoonolevanolev, and since the valve opening amount changes according to the stroke of the spoosole, the stroke amount of the spool is controlled by the solenoid section 20OA. This makes it possible to control the inflow and outflow of fluid.

The solenoid section 200 A is roughly composed of a coil 203, a plunger 201 magnetically attracted to the center boss 202 by energizing the coil 203, The port 2 ◦ 4 connected to the plunger 201 for transmitting the movement of the plunger 201 to the valve section 200 B (specifically, the spool), and various solenoid components And a connector 211 connected to an external power supply to supply current to the coil 203.

Also, the coaxiality of the plunger 201 ゃ rod 204 that reciprocates A first bearing 205 and a second bearing 210 are provided for increasing the load, and the rod 204 fitted to the plunger 201 is connected to the first and second bearings 205, 21. The first bearing 205 is supported by a sleeve 206. The other second bearing 210 is held by a center bolt 202. In addition, it has a fat plate 207 and a mouth plate 209 which form a magnetic path.

Here, the plunger 201 is configured to be located away from the center post 202 in a normal state, that is, in a state where power is not supplied to the coil 203.

In addition, as a configuration in which the plunger 201 is positioned to be separated from the center post 202, generally, the plunger 201 is separated from the center post 202 by an urging member such as a spring. Energize in the direction of In the example shown in the figure, the plunger 201 is provided in the normal state by providing the valve part 200B with the spring 213 which urges the spool in the direction of the solenoid part 200A. It is configured to be separated from the center post 202 by the spring force of this.

By supplying current to the coil 203, the center post 202, the lower plate 209, the case 208, the upper plate 207, the sleeve 206, the plunger 201 and the center post A magnetic path is formed so as to return to 202, and the plunger 201 is magnetically attracted to the center boss 202.

The attraction force F, which causes the plunger 201 to be magnetically attracted to the center post 202, becomes constant even if the stroke t between the plunger 201 and the center post 202 fluctuates. I have. A linear solenoid has such a characteristic that the suction force F is constant with respect to the stroke amount St.

Here, the linear solenoid is explained. EAR) means linearity, linear solenoid refers to a solenoid whose suction force increases linearly in proportion to the current (linear solenoid is also known as proportional solenoid). And also review).

In addition, this linear characteristic (I_F characteristic) is the same linear characteristic (IF characteristic) in the strong stroke range (the part where the suction force F against the stroke is constant). It is generally called the linear region (the linear region is the control zone of the solenoid valve, and the characteristics using this linear region are linear characteristics).

As shown in Fig. 6, the overall characteristics of the suction force F are constant in the middle control zone even if the stroke amount St fluctuates, but are higher than those in the control zone. On the side where the plunger 201 is far from the center post 202, the suction force F decreases as the stroke amount St increases. On the side where the plunger 201 approaches the center boss 202 beyond the control zone, the suction force F increases as the plunger 201 approaches too far. For this reason, in the actual solenoid valve 200, the plunger 201 is set to be able to stroke only in the region of the control zone in FIG.

Then, the suction force F is continuously controlled by the amount of current supplied to the coil 203, and as shown in the control zone of FIG. 6, the suction force F and the spring force of the spring 21 are controlled. By controlling the stroke amount St by stopping the plunger 201 at the balance position between the suction force F and the spring force, the stroke position of the spool is controlled. However, it is considered that various fluid pressure controls such as hydraulic control can be performed by controlling the flow rate of the fluid with the valve opening amount according to the stroke position of the spool.

Here, in the conventional solenoid valve 200, as described above, the stroke amount S of the plunger 201 in the control nozzle zone is as described above. In order to achieve linear characteristics using a linear region where the suction force F is constant regardless of t, a recess 2 2 1 is formed on the end face of the center bolt 202 on the side of the plunger 201 on which the plunger 201 enters and exits. In addition, an annular suction portion 222 is formed on the outer periphery of the concave portion 221 as an outer peripheral tapered portion 222 a having a diameter reduced toward the plunger 201 side.

Next, the operation of obtaining a linear region in which the suction force F is constant even if the stroke amount St fluctuates will be described. FIG. 8 is an explanatory view showing the operation of a solenoid valve according to the prior art to obtain a linear region.

First, as shown in Fig. 8 (a), when the stroke amount St is large, the magnetic flux generated by the current supplied to the coil 203 is mainly the annular attraction of the center post 202. The magnetic force M l acts between the center post 202 and the plunger 201 through the part 222, and the axial component M lcos の of the magnetic force M l moves the plunger 201 to the center post 210. The suction force F to be sucked into 2 becomes

At this time, the cross-sectional area of the annular suction portion 222 on the plunger 201 side is gradually reduced by the outer peripheral tapered portion 222 2a, and the tip of the annular suction portion 222 on the side of the plunger 201 is gradually reduced. Since the passing magnetic flux is restricted, the magnetic force M 1 is small.

Then, as shown in FIG. 8 (b), when the plunger 201 is sucked and the plunger 201 enters into the concave portion 221 of the center post 202 to some extent, the plunger 201 is moved. The cross-sectional area of the ring-shaped suction part 222 increases to the position where it enters, and the magnetic flux passing through the ring-shaped suction part 222 increases, so that the magnetic force Ml also increases.

However, the magnetic force Ml is inclined in the direction toward the outer periphery as the plunger 201 enters the concave portion 221 of the center post 202, that is, the inclination angle 0 increases, so that the attractive force F The axial component M lcos の of the magnetic force M l is maintained at the same magnitude as in FIG. 8 (a). Further, as shown in FIG. 8 (c), when the plunger 201 enters the concave portion 221 of the center post 202, the magnetic flux only passes through the annular attracting portion 222. Without passing between the concave end face 2 21 a and the plunger end face 201 a.

For this reason, the magnetic force M l due to the magnetic flux passing through the annular suction part 2 2 2 tilts in the radial direction, the magnitude of the magnetic force M 1 itself is small, and the axial component M lcos 0 of the magnetic force M l is small, but However, a magnetic force M 2 due to a magnetic flux passing between the concave end face 22 1 a and the plunger end face 201 a also acts. Therefore, the attractive force F is the sum of the axial component M lcos の of the magnetic force M 1 and the magnetic force M 2 having only the axial component, and is maintained at the same magnitude as in FIGS. 8 (a) and 8 (b). It is.

In addition, in FIG. 8 (c), when the plunger 201 enters the concave portion 221 of the center post 202, the concave end surface 221a and the plunger end surface 201a The magnetic force M2 increases due to the narrowing of the gap between them.However, the magnetic flux generated by supplying current to the coil 203 is saturated, and the more the plunger 201 enters the recessed portion 210, the more the circular suction occurs. Since the ratio of the magnetic flux passing through the part 2 222 increases and the ratio of the magnetic flux passing between the recess end surface 2 21 a and the plunger end surface 201 a decreases, the increase in the magnetic force M 2 is moderately suppressed. The increase in the magnetic force M 2 corresponds to the decrease in the axial component M lcos 0 of the magnetic force M l that further tilts in the radial direction, and the axial component M lcos の of the magnetic force M l and the magnetic force M 2 The suction force F, which is the sum of the above, is maintained at the same magnitude as in FIGS. 8 (a), (b) ', and (c).

If the plunger 201 excessively enters the concave portion 221 of the center post 202 excessively, the plunger 201 exceeds the linear region (control zone), and the suction force F sharply increases, and the valve control is reduced. Since it becomes impossible, the second bearing 2100 is interposed in the recess 2221 to prevent the plunger 201 from entering too much. In recent years, downsizing of solenoid valves has been required to reduce the mounting space.

However, if the radial direction of the conventional solenoid valve 200 is simply reduced in size, the cross-sectional area of the annular suction portion 222 and the plunger 201 of the center post 202 becomes small. However, a large magnetic path cross-sectional area required for flowing a large amount of magnetic flux cannot be obtained sufficiently, and the magnetic flux passing therethrough decreases to decrease the magnetic force, thereby reducing the attractive force F.

For this reason, there are measures to supply a high current to the coil 203 and to increase the number of turns of the coil 203. However, measures to supply a high current to the coil 203 impose an excessive load on the mounted device, and furthermore, the magnetic flux does not easily increase in the high current region, and the change in the attractive force F with respect to the current change becomes small. I will. In addition, in the measures for increasing the number of turns of the coil 203, the outer diameter or the axial length of the coil 203 increases due to the increase in the number of turns, which is contrary to miniaturization.

The present invention has been made to solve the above-mentioned problems of the prior art. The purpose of the present invention is to obtain a linear characteristic, increase an attraction force, and further reduce the size and reliability of the device. It is to provide an excellent linear solenoid and a solenoid valve. Disclosure of the invention

The linear solenoid of the present invention

A fixedly arranged center bolt; and a plunger disposed axially opposite to the center bolt and attracted in the axial direction toward the center bolt by a magnetic force of an exciting unit.

In a linear solenoid, wherein a suction force for suctioning the plunger toward a center post in an axial direction has a linear characteristic, A recess in which the plunger enters and exits is formed on the plunger-side end surface of the center boss. An annular suction portion is provided on an outer peripheral portion of the recess. And a tapered portion on the inner periphery that expands in diameter toward the plunger side.

The plunger is characterized in that a suction taper portion is formed on the outer periphery of the center boss side, which is approximately equal to the inner taper portion. Therefore, while obtaining a linear characteristic in which the attraction force is constant even if the stroke amount fluctuates, the magnetic flux by the excitation means is passed between the inner peripheral taper portion of the annular attraction portion and the attraction taper portion of the plunger, and the magnetic force is reduced. By increasing the axial component of the force, the suction force for suctioning the plunger in the axial direction can be increased.

Also, this effect is exhibited even when the cross-sectional area at the root of the annular suction section is smaller than the cross-sectional area of the plunger, so that the outer diameter of the center boss (the outer diameter of the annular suction section) can be reduced. As much as possible, even if the size is reduced in the radial direction, the suction force can be increased while obtaining linear characteristics.

It is preferable that the outer peripheral taper is inclined approximately 20 degrees from the axial direction, and the inner peripheral taper is inclined within 10 degrees or less from the axial direction.

This makes it possible to gradually reduce the cross-sectional area of the annular suction section on the plunger side, thereby reducing the magnetic flux and simultaneously increasing the axial component of the magnetic force. In consideration of the correlation with the outer tapered part that reduces the magnetic flux by gradually reducing the cross-sectional area of the part on the plunger side, the more the outer tapered part is inclined toward the axis center, and the more the inner tapered part becomes The inclination of the outer peripheral taper and inner peripheral taper is set in consideration of the fact that as the angle of inclination of the plunger toward the outer circumference increases, the suction force will decrease if the stroke of the plunger increases. The suction force can be increased while obtaining linear characteristics, and further downsizing can be achieved.

The solenoid valve of the present invention

A fixedly arranged center post, and a plunger disposed axially opposite to the center post and axially attracted toward the center post by a magnetic force of an exciting means,

A solenoid valve in which a suction force for suctioning the plunger toward a center post in an axial direction has a linear characteristic.

A concave portion is formed in the center boss at an end surface of the plunger on the side of the plunger, and an annular suction portion is provided on an outer peripheral portion of the concave portion. And a tapered portion on the inner periphery that expands in diameter toward the plunger side.

The plunger is characterized in that a suction taper portion is formed on an outer periphery of the center boss side, which is inclined substantially equal to the inner peripheral taper portion. Therefore, while obtaining a linear characteristic in which the attraction force is constant even if the stroke amount fluctuates, the magnetic flux by the excitation means is passed between the inner peripheral taper portion of the annular attraction portion and the attraction taper portion of the plunger, and the magnetic force is reduced. By increasing the axial component of the force, the suction force for suctioning the plunger in the axial direction can be increased.

In addition, this effect is exerted even when the cross-sectional area at the root of the annular suction portion is smaller than the cross-sectional area of the plunger, so that the outer diameter of the center post (the outer diameter of the annular suction portion) can be reduced. Even if the size is reduced in the radial direction, the suction force can be increased while obtaining linear characteristics.

It is preferable that the outer peripheral taper is inclined approximately 20 degrees from the axial direction, and the inner peripheral taper is inclined within 10 degrees or less from the axial direction. This makes it possible to gradually reduce the cross-sectional area of the annular suction portion on the plunger side to reduce the magnetic flux and simultaneously increase the axial component of the magnetic force. In consideration of the correlation with the outer peripheral taper part that reduces the magnetic flux by gradually reducing the cross-sectional area of the annular suction part on the plunger side, the more the outer peripheral taper part is inclined toward the axis center, and the more the inner peripheral part Considering that the more the taper section is inclined toward the outer circumference, the greater the stroke of the plunger, the more the suction force will decrease. The suction force can be increased while obtaining linear characteristics, and further downsizing can be achieved. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic configuration sectional view showing a solenoid valve according to an embodiment,

FIG. 2 is an enlarged sectional view showing a main part of the solenoid valve according to the embodiment,

FIG. 3 is an explanatory diagram showing the operation of the solenoid valve according to the embodiment to obtain a reuse area;

FIG. 4 is a diagram showing a solenoid valve according to the embodiment, showing a relationship between a positional relationship between a center post and a plunger, a stroke amount-attraction force characteristic, and a current amount-attraction force characteristic.

FIG. 5 is a characteristic diagram showing the relationship between the suction force and the stroke amount by comparing the solenoid valve according to the embodiment with a comparative example.

FIG. 6 is an overall characteristic diagram showing a relationship between a suction force having a linear region and a stroke amount.

FIG. 7 is a schematic sectional view showing the construction of a solenoid valve according to the prior art. FIG. 8 is an explanatory view showing the operation of a solenoid valve according to the prior art to obtain a linear region. BEST MODE FOR CARRYING OUT THE INVENTION

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are intended to limit the scope of the present invention only to them. is not.

A solenoid valve according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration sectional view of a solenoid valve according to an embodiment. FIG. 2 is an enlarged cross-sectional view showing a main part of a solenoid valve according to the embodiment.

The solenoid valve 100 is composed of a solenoid part 100 A and a valve part 100 B which are linear solenoids.

Here, the valve portion 100B is a spool vano-reve, and a spool 15 is provided inside a valve sleeve 16 which is a main body of the vano-reb portion so as to be able to reciprocate freely. Since the opening area of the opening formed in the valve sleeve 16 in accordance with the stroke position, that is, the valve opening amount changes, the stroke amount of the spool 15 is controlled by the solenoid portion 10 OA. This makes it possible to control the inflow and outflow of fluid.

The solenoid section 10 OA is roughly composed of a coil 3 as an exciting means, a plunger 1 magnetically attracted to the center boss 2 by energizing the coil 3, and a movement of the attracted plunger 1. Rod 7 connected to the plunger 1 for transmitting the pressure to the valve section 10 OB (specifically, the spool 15), and a casing for incorporating various solenoid components. 9 and a connector 17 in which terminals 17a connected to an external power supply for supplying current to the coil 3 are insert-molded.The bobbin 6 around which the coil 3 is wound, and the bobbin 6 Sleeve 4 that guides the plunger 1 and is positioned inside the valve, a shim 8 that makes it easier for the plunger 1 to separate from the center post 2, and a fluid that flows from inside the valve section 100B to the coil 3 side. And a bracket plate 11 for forming a magnetic path and fixing the solenoid valve 100 body at a predetermined position. It has.

Further, by urging the bearing 13 of the rod 7 and the E-ring 18 fixed to the spool 15, the plunger 1 is moved together with the spool 15 through the rod 7 from the center post 2. And a spring 14 for urging in a direction to separate the spring.

Here, in a normal state, that is, in a state where power is not supplied to the coil 3, the plunger 15 is urged in the direction of the solenoid section 10 OA through the E-shaped ring 18, whereby the plunger 1 is moved. Are separated from the center post 2 and located in a direction away from the center post 2.

By supplying a current to the coil 3, the coil 3 generates a magnetic field, and a magnetic path returning to the center post 2, the bracket plate 12, the case 9, the upper plate 11, the plunger 1, and the center post 2 is formed. Once formed, plunger 1 is magnetically attracted to center boss 2.

The attraction force F that causes the plunger 1 to be magnetically attracted to the center post 2 is constant even when the stroke amount St between the plunger 1 and the center post 2 fluctuates. With respect to such a stroke amount St, The linear solenoid with a constant suction force F is linear solenoid.

Here, to explain the linear solenoid, LINEAR means linearity, and linear solenoid refers to a solenoid whose suction force increases linearly in proportion to the current. (The linear solenoid is also called the proportional solenoid).

In addition, this linear characteristic (I-F characteristic) force S, and the portion with similar linear characteristic (IF characteristic) in a certain stroke range (the suction force F to the stroke is constant) The linear region is generally called a linear region (the linear region is a control zone of a solenoid-vanalev, and a characteristic using this linear region is a characteristic of the lower region).

As shown in Fig. 6, the overall characteristics of the suction force F are constant in the middle control zone even if the stroke amount St fluctuates, but the plunger is larger than in the control zone. On the side where 1 is far from the center boss 2, the suction force F decreases as the stroke amount St increases. On the side where the plunger 1 approaches the center post 2 beyond the control zone, the suction force F increases as the plunger 1 approaches too far. For this reason, in the actual solenoid valve 100, the plunger 1 is set to be able to stroke only in the region of the control zone in FIG.

Then, the suction force F is continuously controlled by the amount of current supplied to the coil 3, and as shown in the control zone of FIG. 6, the suction force F and the spring force of the springs 14 are balanced. Thus, the stroke position of the spool 15 is controlled by stopping the plunger 1 at the balance position between the suction force F and the spring force and controlling the stroke amount St, thereby controlling the stroke position of the spool 15. Various fluid pressure controls such as hydraulic pressure control can be performed by controlling the fluid flow rate with the valve opening amount according to the stroke position. If possible, it will be something.

Next, a configuration for obtaining linear characteristics using a linear region in which the suction force F is constant even if the stroke amount St of the solenoid valve 100 according to the present embodiment fluctuates will be described.

In the case of the solenoid valve 100 according to the present embodiment, a concave portion 21 through which the plunger 1 enters and exits is formed on the end face of the center boss 2 on the side of the plunger 1, and an annular suction portion 2 2 is formed on the outer peripheral portion of the concave portion 21. Is provided. The cross-sectional area at the root of the annular suction section 22 is set smaller than the cross-sectional area of the plunger 1.

The annular suction portion 22 has an outer peripheral tapered portion 22 a on the outer periphery that decreases in diameter toward the plunger 1, and an inner peripheral taper portion 2 2 b on the inner periphery that increases in diameter toward the plunger 1. Is formed. Further, the plunger 1 has a configuration in which a suction taper portion 1a that is inclined at the same angle as the inner peripheral taper portion 22b of the annular suction portion 22 is formed on the outer periphery of the center boss 2 side. The effect of obtaining the linear characteristics operating in the linear region in this case will be described. FIG. 3 is an explanatory view showing the operation of the solenoid valve according to the embodiment for obtaining linear characteristics.

First, as shown in FIG. 3 (a), when the stroke amount St is large, the magnetic flux generated by supplying current to the coil 3 is mainly generated by the annular suction portion 2 2 of the center post 2. , A magnetic force Ml acts between the center boss 2 and the plunger 1, and an axial component M 1 cos 0 of the magnetic force Ml becomes a suction force F for attracting the plunger 1 to the center post 2. At this time, the cross-sectional area of the annular suction portion 22 on the plunger 1 side is gradually reduced by the outer peripheral taper portion 22a and the inner peripheral taper portion 22b, and the tip of the annular suction portion 22 on the plunger 1 side is gradually reduced. Since the magnetic flux passing through is narrowed, the magnetic force M 1 is small.

Here, in the present embodiment, the cross-sectional area at the root of the annular suction portion 22 is Since the current is supplied to the coil 3, the overall magnetic flux generated by the coil 3 is smaller than the cross-sectional area of the lancer 1, but the magnetic flux is reduced by the inner peripheral taper portion 2 2 b of the annular suction portion 22 and the plunger 1. Since the magnetic force Ml passes through the space between the suction tapered portions 1a, the axial component Mlcos0 increases, and a large suction force F can be obtained.

Then, as shown in FIG. 3 (b), when the plunger 1 is sucked and the plunger 1 enters the recess 21 of the center boss 2 to some extent, the annular suction portion 2 reaches the position where the plunger 1 enters. The cross-sectional area of No. 2 increases, and the magnetic flux passing through the annular suction portion 22 increases, so that the magnetic force Ml also increases.

However, the magnetic force Ml is inclined in the radial direction as the plunger 1 enters the concave portion 21 of the center post 2, that is, the inclination angle 0 increases, so that the axial direction of the magnetic force Ml as the attractive force F The component M lcos 0 is kept the same size as in FIG. 3 (a).

Further, as shown in FIG. 3 (c), when the plunger 1 enters the concave portion 21 of the center post 2, the magnetic flux not only passes through the annular suction portion 22 but also the concave end surface 21. It will also pass between a and the plunger end face 1b.

For this reason, the magnetic force Ml due to the magnetic flux passing through the annular suction part 22 is inclined in the radial direction, the magnitude itself of the magnetic force M1 is small, and the axial component M1cos0 of the magnetic force Ml is small. However, a magnetic force M 2 due to the magnetic flux passing between the concave end face 21a and the plunger end face 1b also acts. Therefore, the attractive force F is the sum of the axial component Mlcos 0 of the magnetic force Ml and the magnetic force M2 having only the axial component, and is maintained at the same magnitude as in FIGS. 3 (a) and 3 (b). It is.

In addition, from FIG. 3 (c), when the plunger 1 further enters the concave portion 21 of the center post 2, the concave end surface 21a and the plunger end surface Although the gap between 1b becomes narrower and the magnetic force M2 becomes larger, the entire magnetic flux generated by supplying current to the coil 3 is saturated, and the more the plunger 1 enters the recess 2 Since the ratio of magnetic flux passing through 22 increases and the ratio of magnetic flux passing between concave end face 21a and plunger end face 1b decreases, the increase in magnetic force M2 is moderately suppressed, and magnetic force M2 is reduced. The increase corresponds to a small amount of the axial component M 1 cos of the magnetic force M 1 that tilts further in the radial direction, and the suction force F is the same as in Figs. 3 (a), (b), and (c). Size is kept.

Excessive penetration of the plunger 1 into the concave portion 2 1 of the center post 2 will exceed the linear range (control zone), and the suction force F will rapidly increase, and valve control will occur. In order to prevent the plunger 1 from becoming excessive, the plunger 1 is prevented from entering too much by interposing the nonmagnetic shim 8 in the recess 21.

In the solenoid valve 100 according to the present embodiment, the positional relationship between the center boss 2 and the plunger 1 in the suction section, the stroke amount St—the suction force F characteristic, and the current amount I—the suction force Fig. 4 shows the relationship between the F characteristic and. In the characteristic of the current amount I-attraction force F shown in the upper left of FIG. 4, the attraction force F increases in proportion to the current amount I. However, in the low current region, the rate of increase of the attractive force with respect to the current is small, actually.

Also, as can be seen from FIG. 4, the outer taper portion 22a and the inner taper portion 22b are located in a region wider than the control stroke range (linear region) for controlling the solenoid valve 10 °. Is provided.

As described above, in the present embodiment, the linear region in which the suction force F is constant even when the stroke amount fluctuates is used in the control zone, that is, in the strokeable region of the plunger 1. While obtaining linear characteristics, the magnetic flux is applied to the inner peripheral taper portion 2 2 b of the annular suction portion 22 and the suction taper of the plunger 1. By passing between the parts 1a, the axial component M lcos の of the magnetic force M l can be increased, and the suction force F for sucking the plunger 1 in the axial direction can be increased.

The inner peripheral taper portion 2 2b of the annular suction portion 22 gradually reduces the cross-sectional area of the annular suction portion 22 on the side of the plunger 1 to reduce the magnetic flux and the axial component M lcos of the magnetic force M l. Since the action of increasing 0 is performed at the same time, it is necessary to gradually reduce the cross-sectional area of the annular suction portion 22 on the plunger 1 side and satisfy the correlation with the outer peripheral taper portion that performs the action of reducing the magnetic flux.

For this reason, in order to obtain a large suction force F while obtaining a linear region, in consideration of the above properties, the annular suction portion 22 is provided with both the outer tapered portion 22 a and the inner tapered portion 22 b. It is necessary to set it with an appropriate setting.

It is particularly preferable that the outer taper portion 22a is inclined approximately 20 degrees from the axial direction, and the inner taper portion 22b is inclined 10 degrees or less from the axial direction. It is.

This case will be described with reference to FIG. FIG. 5 illustrates the setting of the angle between the outer peripheral tapered portion 22a and the inner peripheral tapered portion 22b at the upper part. That is, in FIG. 5, the outer taper portion 22a is set to a degree from the axial direction, and the inner taper portion 22b is set to b degree from the axial direction.

Then, (1) shows a case in which the value of “a” is approximately 20 degrees and the value of “b” is approximately 3 degrees in the case where the above-described range of the present embodiment is particularly defined. On the other hand, (2) to (5) are comparative examples, (2) shows characteristics in which a is less than 20 degrees and b is about 3 degrees, (3) shows that a is more than 20 degrees, (4) shows the characteristic when a is about 20 degrees, b is more than 10 degrees, and (5) shows the characteristic when a is about 20 degrees and b is about 0 degree. It shows the characteristics as follows. (2) to (5) The dashed lines are used for easy comparison. The characteristics of (1) were also shown.

As described above, in (2) to (5), it is difficult to secure the linear area of the control zone. Also, in (5), the magnetic force is reduced and the suction force is reduced as a whole, or the linear region cannot be partially formed.

As is clear from the above description of FIG. 5, the outer peripheral taper portion 22a is inclined approximately 20 degrees from the axial direction, and the inner peripheral taper portion 22b is inclined within 10 degrees or less from the axial direction. With this setting, good linear characteristics can be obtained with a large suction force.

On the other hand, since the inner taper portion 2 2 b of the annular suction portion 22 and the suction taper portion 1 a of the plunger 1 are equally inclined, the distance between the inner taper portion 22 b and the suction taper portion 1 a is increased. Since the distances facing each other are all equal, the magnetic flux passing through one location is not concentrated, unnecessary leakage of the magnetic flux is prevented, and the magnetic flux is efficiently converted to magnetic force M 1 Can be. In the present embodiment described above, although the cross-sectional area at the root of the annular suction section 22 is smaller than the cross-sectional area of the plunger 1, the linear characteristics using the linear area are obtained. The suction force F can be increased.

According to this, when comparing the conventional technology and the solenoid valve of the present embodiment, even if both plungers have the same outer diameter, the outer diameter of the center post 2 which is slightly larger than the plunger 1 in the present embodiment. Since the diameter (the outer diameter of the annular suction portion 22) can be reduced, the solenoid valve 100 of the present embodiment can be reduced in size as compared with the conventional technology.

In the actual verification, the solenoid valve 100 of the present embodiment was set so that the cross-sectional area of the root of the annular suction part 22 was set to 60% of the cross-sectional area of the plunger 1 and the outer diameter of the plunger 1 was the same as that of the prior art. (When ί »1 O mm The outer diameter of the solenoid valve 100 was φ31 mm in the prior art, whereas it was reduced to φ28 mm in the present embodiment.

According to this verification, the solenoid valve 100 of the present embodiment has a magnetic flux acting as a magnetic force because the cross-sectional area of the root of the annular suction part 22 is set to 60% of the cross-sectional area of the plunger 1. It is thought that the suction force F applied to the plunger 1 increased by 20% as compared with the conventional technology, although it is considered that the pressure decreased.

Next, a preferred application example of the solenoid valve 100 according to the present embodiment will be described.

In engines such as automobiles, the intake and exhaust valves of the engine are opened and closed by rotation of camshafts. However, by controlling the valve timing appropriately according to the operating conditions (high speed / low speed), fuel efficiency can be reduced. It becomes possible to obtain high exhaust gas purification.

This valve timing control can be performed by shifting the camshaft in the rotation direction and changing the phase, and a technique for performing this by a solenoid valve is known as a known technique.

Here, in order to shift the cam shaft in the rotation direction, hydraulic control using a solenoid valve is performed.However, a solenoid valve is installed on the path of the engine oil flow path due to the layout space and other factors.

It is common to use engine oil.

Conventionally, a solenoid valve that performs on / off control has been used to perform control in two different states, high speed and low speed.In recent years, more precise control has been performed. For this reason, solenoid valves capable of linear control have been used.

Therefore, the above-described solenoid valve according to the present embodiment is replaced with a linear solenoid for such a valve timing control (VTC). It can be suitably used as a valve.

As described above, the solenoid valve 100 of the present embodiment is effective as a linear solenoid valve having a high stroke amount (1.5 mm or more), such as the above-mentioned spoon rebag rev type.

The solenoid portion 100A of the solenoid valve 100 according to the present embodiment is used not only for the solenoid valve as in the present embodiment but also for a device for adjusting the axial position. It can be used as a linear solenoid as a driving source. Industrial applicability

As described above, according to the present invention, the center post is provided with a concave portion on the plunger side end surface where the plunger enters and exits, an annular suction portion is provided on the outer peripheral portion of the concave portion, and the annular suction portion is provided on the outer periphery toward the plunger side. An outer taper portion that reduces the diameter and an inner taper portion that expands toward the plunger side on the inner circumference are formed. By forming the suction taper part, the magnetic flux by the excitation means is attracted to the inner peripheral taper part of the annular suction part and the plunger while obtaining the linear characteristic that the suction force is constant even if the storage amount varies. By passing between the taper portions, the axial component of the magnetic force can be increased, and the suction force for suctioning the plunger in the axial direction can be increased.

Claims

The scope of the claims

1. A fixedly arranged center post, and a plunger arranged in the axial direction with respect to the center post and attracted in the axial direction toward the center post by the magnetic force of the exciting means,

In a linear solenoid, the suction force of drawing the plunger toward the center boss in the axial direction has a linear characteristic.

A concave portion is formed in the center boss at the end surface of the plunger on the side of the plunger, and an annular suction portion is provided at an outer peripheral portion of the concave portion. And a tapered portion on the inner periphery that expands in diameter toward the plunger side.

A linear solenoid, wherein the plunger is formed with a suction taper portion on the outer periphery of the center boss side, which is inclined substantially equal to the inner peripheral taper portion.

2. The outer peripheral taper portion is inclined approximately 20 degrees from the axial direction, and the inner peripheral taper portion is inclined within 10 degrees or less from the axial direction. The linear solenoid described in item 1.

3. A fixedly arranged center post, and a plunger that is arranged in the axial direction with respect to the center post and is attracted in the axial direction toward the center post by the magnetic force of the exciting means.

In a solenoid valve, the suction force for suctioning the plunger in the axial direction toward the center boss has a linear characteristic.

A recess is formed in the center boss at the plunger side end surface so that the plunger can move in and out. An annular suction portion is provided on the outer periphery of the recess. And a tapered portion on the inner periphery that expands in diameter toward the plunger side. A solenoid taper, wherein a suction taper portion is formed on the plunger at an outer periphery of the center boss side, the suction taper portion being inclined substantially equal to the inner peripheral taper portion.

4. The outer peripheral taper portion is inclined approximately 20 degrees from the axial direction, and the inner peripheral taper portion is inclined within 10 degrees or less from the axial direction. The solenoid valve according to item 3.