JP7308795B2 - coil unit - Google Patents

Description

The present invention relates to a coil unit that controls an electromagnetic valve.

As a technique related to a coil unit, Patent Document 1 discloses a housing having a cylindrical sleeve, a valve body, and a stator, a plunger is movably arranged inside the sleeve, and a coil is mounted on the outer periphery of the sleeve. is provided and the hydraulic fluid is controlled by a rod that moves integrally with the plunger.

In Patent Document 1, a stator is fixed to one end of the sleeve, a valve body is fixed to the other end of the sleeve, and a compression coil spring is arranged between the stator and the plunger.

JP 2019-94916 A

However, with the technique disclosed in Patent Document 1, axial play may occur due to the tolerance of each member at the fixed portion between the sleeve and the stator. If such backlash occurs, the sleeve may move together with the plunger when the plunger moves, and the suction force acting on the plunger may become unstable.

For these reasons, it is desired to easily and appropriately define the axial position of the sleeve in the coil unit provided with the sleeve disposed between the housing and the plunger.

The characteristic configuration of the coil unit according to the present invention includes a housing in which a cylindrical space centered on an axis is formed, a coil portion arranged outside the cylindrical space in the housing, and the cylindrical space. a sleeve accommodated in the cylindrical space along the inner peripheral surface; a plunger accommodated inside the sleeve so as to be movable in a direction along the axis; a support disposed at a position adjacent to one end side of the plunger in a direction along the line so that an outer peripheral surface thereof faces an inner peripheral surface of the cylindrical space ; A rod connected to the other end side opposite to the side on which the support is arranged in the direction along the , and a spring that applies a biasing force between the support and the plunger, and the sleeve The length of the sleeve in the direction along the axis is such that one end abuts the support and the other end of the sleeve abuts the end surface of the cylindrical space in the direction along the axis. The one end of the sleeve has, on its inner peripheral side, an inclined surface whose inner diameter increases toward the support in the direction along the axis , and this inclined surface is brought into contact with the outer circumference of the support. It is in the point of letting

According to this characteristic configuration, the other end of the sleeve abuts on one end surface of the cylindrical space and the other end abuts on the support, so that the position along the axis can be easily and appropriately determined. It becomes possible. In addition, one end of the sleeve has an inclined surface on the inner peripheral side, and in a state in which this inclined surface is brought into contact with the outer periphery of the support, the one end of the sleeve overlaps the outer peripheral portion of the support. Even if the length of the sleeve varies somewhat, the position of the sleeve can be maintained by reliably bringing one end of the sleeve into contact with the support.
Therefore, in the coil unit with the sleeve arranged between the housing and the plunger, the axial position of the sleeve is easily and appropriately defined.

As a configuration in addition to the above configuration, a contact surface of the outer periphery of the support body with which the inclined surface of the sleeve abuts may be formed in a posture along the inclined surface.

According to this, the abutment surface formed on the outer periphery of the support and the inclined surface of the sleeve are formed in a posture along each other, so that the amount of overlap between the respective surfaces in the axial direction can be increased. To facilitate the manufacture of a sleeve by stabilizing the contact state and enlarging the tolerance when manufacturing the sleeve.

As a configuration in addition to the above configuration, the cross section of the inclined surface of the sleeve cut along a virtual plane including the axial center bulges toward the abutment surface in the middle of the region extending from the outer circumference to the inner circumference of the sleeve. It may be formed in an arc shape.

According to this, since the cross section of the inclined surface of the sleeve is arc-shaped, it is possible to reduce the area of the portion where the inclined surface abuts against the contact surface of the support. Position can be held stably.

As a configuration in addition to the above configuration, a housing having a columnar space centered on an axis, a coil portion arranged outside the columnar space in the housing, and an inner peripheral surface of the columnar space a sleeve accommodated in the cylindrical space along the axis; a plunger accommodated inside the sleeve so as to be movable in a direction along the axis; and a direction along the axis inside the cylindrical space. and a spring that exerts a biasing force between the support and the plunger, one end of the sleeve abuts the support and the sleeve is in contact with the support. The length of the sleeve in the direction along the axis is set so that the other end abuts the end face in the direction along the axis of the cylindrical space, and the one end of the sleeve extends along the inner circumference of the cylindrical space. a coil unit having an inclined surface on the side of the coil unit, the inclined surface being brought into contact with the outer circumference of the support, wherein the contact surface of the outer circumference of the support with which the inclined surface of the sleeve abuts a gap is formed between the outer circumference of the sleeve and the inner circumference of the cylindrical space, and the inclined surface of the sleeve is aligned with the contact surface of the support; In the contact state, the outer peripheral edge of the one end of the sleeve may contact the inner surface of the cylindrical space.

According to this, the other end of the sleeve abuts on one end surface of the cylindrical space and the one end abuts on the support, so that the position in the direction along the axis can be determined easily and appropriately. Become. In addition, one end of the sleeve has an inclined surface on the inner peripheral side, and in a state in which this inclined surface is brought into contact with the outer periphery of the support, the one end of the sleeve overlaps the outer peripheral portion of the support. Even if the length of the sleeve varies somewhat, the position of the sleeve can be maintained by reliably bringing one end of the sleeve into contact with the support. Further, according to this, since the abutment surface formed on the outer periphery of the support and the inclined surface of the sleeve are formed so as to follow each other, it is possible to increase the amount of overlap between the respective surfaces in the axial direction. , the abutment state is stabilized, and the sleeve can be manufactured with greater tolerance, thereby facilitating the manufacture of the sleeve.
According to this, in a state in which the inclined surface formed at one end of the sleeve and the contact surface of the support are in contact with each other, the one end of the sleeve is elastically deformed so as to expand its diameter, and the outer peripheral edge of the one end of this sleeve is formed into a cylindrical shape. It is also possible to contact the inner surface of the space. By bringing the outer peripheral edge of one end of the sleeve into contact with the inner surface of the cylindrical space in this way, it is possible to stabilize the position of the sleeve in the radial direction.

It is a sectional view of a coil unit. FIG. 4 is a cross-sectional view showing the arrangement of sleeves; It is sectional drawing which shows arrangement|positioning of the sleeve of another embodiment (a).

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.
[Basic configuration]
FIG. 1 shows a coil unit C that actuates the spool of the proportional solenoid valve in the direction along the axis X. As shown in FIG. Although the entire proportional solenoid valve is not shown in FIG. 1, this coil unit C is arranged at one end of the proportional solenoid valve. This electromagnetic proportional valve can be used, for example, in a vehicle such as a tractor to control the engagement and disengagement of a clutch by hydraulic pressure and the drive of a hydraulic actuator.

[Coil unit]
As shown in FIGS. 1 and 2, the coil unit C includes a housing 1 in which a cylindrical space S centered on an axis X is formed, a holder 2 supported outside the housing 1, and a coil portion 3 disposed outside the columnar space S. Further, the coil unit C includes a sleeve 4 accommodated along the inner peripheral surface of the cylindrical space S, a plunger 5 accommodated inside the sleeve 4 so as to be movable in the direction along the axis X, and a cylindrical A support 6 is housed in the space S at a position adjacent to the plunger 5, and a spring 7 exerts a biasing force between the support 6 and the plunger 5 in a direction along the axis X.

The housing 1 is constructed by connecting a first housing 1a made of a magnetic material such as iron and a second housing 1b made of a magnetic material such as iron in a direction along the axis X. A columnar space S is formed in a region extending from 1a to the second housing 1b. One end face (the right face in FIG. 1) of the cylindrical space S is referred to as a first end face Sa, and the other end face (the left face in FIG. 1) opposite to which the support 6 is arranged. is called a second end face Sb.

The first housing 1a has a through hole 1h that communicates with the outside along the axis X from the first end surface Sa of the columnar space S. As shown in FIG. A rod 8 having a proximal end connected to the plunger 5 is inserted through the through hole 1h, and a distal end of the rod 8 is connected to a spool (not shown) of the electromagnetic proportional valve.

The coil portion 3 is accommodated in an annular space formed in a region extending from the first housing 1a to the second housing 1b. The coil portion 3 is constructed by winding a coil 3b made of a good conductor around a bobbin 3a made of a non-magnetic material, and exposing a portion of the inner circumference of the bobbin 3a to the cylindrical space S.

A connector portion 2a is formed integrally with the holder 2, and a terminal 2c for supplying current to the coil 3b of the coil portion 3 is formed to the connector portion 2a.

The plunger 5 is made of a magnetic material such as iron, and has a spring space 5a in which a spring 7 is accommodated on the side facing the support 6 in the direction along the axis X as shown in FIG. A communication hole 5b communicating with the spring space 5a and extending in the opposite direction to the support 6 is formed coaxially with the axis X. As shown in FIG. Since the coil unit C has a structure that allows oil to flow into the cylindrical space S, the rod 8 is made of a tubular material that allows the oil to flow in the spring space 5a when the plunger 5 is actuated.

The support 6 is arranged at a position where the surface opposite to the plunger 5 is brought into contact with the second end surface Sb. Further, as shown in FIG. 2, the outer diameter of the support 6 is made slightly smaller than the inner diameter of the cylindrical space S. As shown in FIG. In this support 6, the outer diameter of the side close to the plunger 5 is made smaller than the outer diameter of the side close to the second end surface Sb. The outer diameters of the support body 6 are thus made different, and the contact surface 6s, which is an inclined surface, is formed between the different outer diameters. A spring support recess 6a for accommodating the spring 7 is formed on the side of the support 6 facing the plunger 5. As shown in FIG.

The spring 7 is of a compression coil type and is arranged in a region spanning the spring space 5 a of the plunger 5 and the spring support recess 6 a of the support 6 . The spring 7 applies a biasing force to the plunger 5 in the projecting direction (right side in FIG. 1).

[Coil unit: sleeve]
As shown in FIG. 2 , the sleeve 4 is made of a thin cylindrical stainless steel material and is arranged between the inner periphery of the cylindrical space S and the outer periphery of the plunger 5 . Further, the coil unit C forms a small gap between the outer surface of the sleeve 4 and the inner surface of the cylindrical space S, and forms a small gap between the inner surface of the sleeve 4 and the outer surface of the plunger 5. .

The sleeve 4 is formed with a length extending from the first end surface Sa of the cylindrical space S to the contact surface 6 s on the outer periphery of the support 6 . That is, the contact surface 6s formed on the support 6 is formed in a conical surface whose diameter decreases toward the plunger 5 side. In addition, the first end portion 4a (one end of the sleeve 4) of the sleeve 4 that contacts the contact surface 6s of the support body 6 has an inclined surface formed so that the inner peripheral side of the sleeve 4 is inclined along the contact surface 6s. 4t, and the second end portion 4b (the other end of the sleeve 4) that abuts on the first end surface Sa is a flat surface perpendicular to the axis X. As shown in FIG. The inclined surface 4t is formed by processing such that the inner diameter of the sleeve 4 increases toward the first end 4a.

The length of the sleeve 4 from the first end 4a to the second end 4b is, for example, slightly smaller than the dimension at which the second end 4b comes into contact with the contact surface 6s of the support 6 in the holding position shown in FIG. It is possible to design for a long time. In addition, the cross-sectional shape of the inclined surface 4t of the sleeve 4 cut along a virtual plane including the axial center of the first end portion 4a expands toward the contact surface 6s at the middle of the area extending from the outer circumference to the inner circumference of the sleeve 4. It is shaped like an arc.

As a result, even if the total length of the sleeve 4 is slightly shorter than the design, the inclined surface 4t of the second end portion 4b can be reliably brought into contact with the contact surface 6s of the support 6, and the total length of the sleeve 4 is slightly longer than the design. Even in this case, the inclined surface 4t of the second end portion 4b can be brought into contact with the contact surface 6s of the support body 6 so as to ride on the contact surface 6s, as shown enlarged in FIG.

In particular, when the inclined surface 4t is brought into contact with the contact surface 6s so as to ride on the contact surface 6s, the first end portion 4a expands in diameter due to elastic deformation. It is possible to make contact with the inner surface of the space S, and the stabilization of the posture of the sleeve 4 is also realized.

Furthermore, since the cross-sectional shape of the inclined surface 4t of the sleeve 4 is circular, the contact position is fixed by reducing the contact area when this inclined surface contacts the contact surface 6s of the support 6. Stabilize the position of the support 6 and the sleeve 4. The sleeve 4 determines the position of the plunger 5 in the cylindrical space S and enhances the slidability of the plunger 5 .

[Action and effect of the embodiment]
In the coil unit C, when the position of the support 6 or the sleeve 4 in the direction along the axis X is not determined, the biasing force acting on the plunger 5 from the spring 7 changes. Even when the force is increased at a constant rate, the thrust of the plunger 5 changes greatly, and the performance of controlling hydraulic oil and pilot oil with the electromagnetic proportional valve may be degraded.

To address such inconvenience, the second end portion 4b of the sleeve 4 is in contact with the first end surface Sa of the cylindrical space S, and the inclined surface 4t of the first end portion 4a of the sleeve 4 is Displacement in the direction along the axis X of the support 6 and the sleeve 4 is prevented by contacting the contact surface 6 s of the support 6 . As a result, when the current supplied to the coil portion 3 is increased at a constant rate, the thrust of the plunger 5 can be made proportional to the current.

Further, in this coil unit C, since the sleeve 4 is arranged at a position covering the outer periphery of the plunger 5, the plunger 5 is displaced in a specific direction of the inner periphery of the cylindrical space S (the center line of the plunger 5 is the axis). It is displaced in a direction away from the core X), and is adsorbed to the inner periphery of the cylindrical space S, thereby suppressing the inconvenience of unstable operation.

Therefore, when an electric current is supplied to the coil 3b of the coil portion 3, the plunger 5 is operated in the direction of projecting the rod 8 by the action of magnetism, and the force acting on the rod 8 causes the working oil in the electromagnetic proportional valve to Realize high-precision control of pilot oil.

In addition, since the thickness of the sleeve 4 can be reduced, the magnetism acting on the plunger 5 from the coil portion 3 is not attenuated and is supplied to the coil portion 3, for example, as compared with the case where the sleeve 4 is thick. No need to increase the current.

[Another embodiment]
The present invention may be configured as follows other than the above-described embodiments (components having the same functions as those of the embodiments are given the same numbers and symbols as those of the embodiments).

(a) As shown in FIG. 3, a contact portion 6t having an outer diameter capable of coming into contact with the inclined surface 4t of the sleeve 4 is formed at a portion of the support 6 facing the plunger 5. As shown in FIG. In the configuration of this alternative embodiment (a), since the angle of the cross-sectional shape of the contact portion 6t is a right angle, the structure is simpler and easier to manufacture than the structure in which the inclined contact surface 6s is formed on the outer periphery of the support 6. becomes.

(b) The cross-sectional shape of the inclined surface 4t of the sleeve 4 is formed linearly. This structure has a simpler shape than the one having an arcuate cross-sectional shape as shown in the embodiment, and facilitates manufacturing. Also, the sleeve 4 can be made of resin.

INDUSTRIAL APPLICATION This invention can be utilized for the coil unit which controls the spool of an electromagnetic valve.

1 housing 3 coil part 4 sleeve 4a first end (one end)
4b second end (other end)
4t inclined surface 5 plunger 6 support 6s contact surface 7 spring S columnar space Sa first end surface (end surface)
X-axis center

Claims (4)

a housing in which a columnar space is formed around an axis;
a coil portion arranged outside the columnar space in the housing;
a sleeve accommodated in the columnar space along the inner peripheral surface of the columnar space;
a plunger housed inside the sleeve so as to be movable in a direction along the axis;
a support arranged inside the cylindrical space at a position adjacent to one end side of the plunger in a direction along the axis so that an outer peripheral surface faces an inner peripheral surface of the cylindrical space ;
a rod inserted through the housing and connected to the other end side of the plunger opposite to the side on which the support is arranged in the direction along the axis of the plunger;
a spring that exerts a biasing force between the support and the plunger;
The length of the sleeve in the direction along the axis such that one end of the sleeve abuts the support and the other end of the sleeve abuts the end surface of the cylindrical space in the direction along the axis. is set and
The one end of the sleeve has, on its inner peripheral side, an inclined surface whose inner diameter increases toward the support body in the direction along the axis , and this inclined surface is brought into contact with the outer periphery of the support body. coil unit. 2. The coil unit according to claim 1, wherein a contact surface of the outer circumference of the support body with which the inclined surface of the sleeve abuts is shaped so as to follow the inclined surface. A cross section of the inclined surface of the sleeve cut along an imaginary plane containing the axis is formed in an arc shape in which a middle portion of a region extending from an outer circumference to an inner circumference of the sleeve bulges toward the contact surface. Item 3. The coil unit according to item 2. a housing in which a columnar space is formed around an axis;
a coil portion arranged outside the columnar space in the housing;
a sleeve accommodated in the columnar space along the inner peripheral surface of the columnar space;
a plunger housed inside the sleeve so as to be movable in a direction along the axis;
a support disposed at a position adjacent to the plunger in the direction along the axis inside the cylindrical space;
a spring that exerts a biasing force between the support and the plunger;
The length of the sleeve in the direction along the axis such that one end of the sleeve abuts the support and the other end of the sleeve abuts the end surface of the cylindrical space in the direction along the axis. is set and
A coil unit in which the one end of the sleeve has an inclined surface on its inner peripheral side, and the inclined surface is brought into contact with the outer periphery of the support,
forming an abutting surface of the outer circumference of the support with which the inclined surface of the sleeve abuts in a posture along the inclined surface;
A gap is formed between the outer circumference of the sleeve and the inner circumference of the cylindrical space,
A coil unit in which the outer peripheral edge of the one end of the sleeve is in contact with the inner surface of the columnar space while the inclined surface of the sleeve is in contact with the contact surface of the support.

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