JPH10246352A - Linear solenoid and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of parts and the size in the radial direction of a linear solenoid by winding a coil through an electrical insulation material layer made by coating an electrical insulation material on an outer peripheral wall of a core of a hollow cylindrical body which constitutes a part of a magnetic circuit and fitting a shaft inside the core slidably. SOLUTION: A linear solenoid consisting of a pressure adjusting valve part 1 and a thrust generation part 2 forms an electrical insulation material layer 241 by coating an electrical insulation material on an outer peripheral wall 212 of a core 21 of a hollow cylindrical body which constitutes a part of a magnetic circuit of the thrust generation part 2 and forms a coil 22 by winding a wire around the outer peripheral wall 212 of the core directly. Moreover, a lubrication material is coated on an inner peripheral wall of the core 21 to form a lubrication material layer 242, and a shaft 23 connected with a spool 11 of the pressure adjusting valve part 1 is fitted inside the core 21. In this way, by winding the coil wire around the outer peripheral wall 212 of the core 21 directly, a conventional bobbin becomes unnecessary, and it is possible to reduce the number of parts and the size in the radial direction of the linear solenoid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core of a hollow cylindrical body constituting a part of a magnetic circuit, an electric insulating material layer formed by coating an outer peripheral wall of the core with an electric insulating material, A coil in which a winding is wound directly on the outer peripheral wall of the core on which an insulating material layer is formed, and a shaft slidably disposed inside the core, reducing the number of parts, and reducing the size in the radial direction. The present invention relates to a linear solenoid capable of supporting a shaft by reducing the size thereof and a method of manufacturing the same.

[0002]

2. Description of the Related Art In a conventional linear solenoid, as shown in FIG. 7, a coil assembly in an electromagnet section M has a bush or bearing slidably supporting a shaft ST for transmitting an electromagnetic attraction force to a pressure regulating valve section S. B, a hollow cylindrical core F disposed on the inner peripheral wall, a cylindrical bobbin V having a connector CT disposed on a flange FF at one end of the outer peripheral wall of the core F, and an outer peripheral wall of the bobbin V And a coil C formed by winding a coil winding around the coil.

[0003]

In the above-described conventional linear solenoid, the cylindrical bobbin V is disposed on the outer peripheral wall of the core F in order to ensure insulation between the core F and the coil winding C. However, since the coil winding tension at the time of winding the coil winding around the bobbin V is relatively large, a wall thickness of about several mm is used in order to prevent deformation of the cylindrical portion of the bobbin V. However, there is a problem that the size of the electromagnet portion itself in the radial direction increases.

In order to reduce the thickness of the side wall of the bobbin V, the core F is inserted into the inner wall of the bobbin V,
Thereafter, it is conceivable to wind the coil winding around the outer wall of the bobbin V. However, there has been a problem that the number of assembling steps increases and the electromagnet portion itself becomes complicated.

Further, in order to slidably support the shaft ST for transmitting electromagnetic attraction to the pressure regulating valve portion, a supporting member such as the bush or the bearing B or a spring is separately provided on an inner peripheral wall of the core F. Therefore, not only the number of parts increases, but also the bush and the bearing B
However, there is a limit in reducing the thickness of the electromagnet portion because it is a single product, and there is a problem that the radial dimension of the electromagnet portion itself becomes large.

Therefore, the present inventors coated an outer peripheral wall of a core of a hollow cylindrical body constituting a part of a magnetic circuit in which a shaft was slidably disposed, and coated the outer peripheral wall with an electrically insulating material. While focusing on the first technical idea of the present invention, in which a material layer is formed and a coil winding is wound directly on the outer peripheral wall of the core on which the electrically insulating material layer is formed,
Focusing on the second technical idea of the present invention of forming a lubricating material layer by coating a lubricating material on the inner peripheral wall of the core, as a result of further research and development, the need for bobbins, bearings, and support members has been eliminated. Thus, the present invention has been achieved which achieves the object of reducing the number of parts and reducing the size in the radial direction.

[0007]

A linear solenoid according to the present invention (a first invention according to claim 1) includes a hollow cylindrical core constituting a part of a magnetic circuit and an outer peripheral wall of the core. An electrically insulating material layer formed by coating an electrically insulating material; a coil having a winding wound directly around an outer peripheral wall of the core on which the electrically insulating material layer is formed; and a coil slidably disposed inside the core. And an installed shaft.

[0008] The present invention (the second invention described in claim 2)
The linear solenoid according to the first aspect, wherein the inner peripheral wall of the core is coated with a lubricating material to form a lubricating material layer.

The present invention (third invention described in claim 3)
The linear solenoid according to the second aspect, wherein the electrically insulating material layer coated on the outer peripheral wall of the core, and the lubricating material layer coated on the inner peripheral wall of the core,
Both are made of the same resin material.

The present invention (the fourth invention described in claim 4)
According to the third aspect of the present invention, in the third aspect, in the third aspect, a concave portion in which the winding of the coil is directly wound is formed in a portion including an axial center of the outer peripheral wall of the core.

The present invention (fifth invention described in claim 5)
According to the fourth aspect of the present invention, in the fourth aspect of the present invention, in the fourth aspect, both ends of the inner peripheral wall of the core in the axial direction protrude inward in the radial direction, and a bearing portion that supports the shaft is formed.

The present invention (the sixth invention described in claim 6)
The linear solenoid according to the third aspect, wherein the electrically insulating material layer coated on the outer peripheral wall of the core, and the lubricating material layer coated on the inner peripheral wall of the core,
Both are made of Teflon.

The present invention (the seventh invention described in claim 7)
According to the third aspect of the present invention, in the linear solenoid, the coil is covered with an electrically insulating material.

The present invention (an eighth invention described in claim 8)
The method of manufacturing a linear solenoid includes a step of coating a resin material on a surface of a core constituting a part of a magnetic circuit, a step of directly winding a coil winding around an outer periphery of the core, and a step of coating the wound coil with a coating material. And a step of coating with.

The present invention (a ninth invention described in claim 9)
The method for manufacturing a linear solenoid according to the eighth aspect of the present invention includes a step of processing a necessary portion of the core, the surface of which is coated with a resin material.

According to a tenth aspect of the present invention, in the method for manufacturing a linear solenoid according to the ninth aspect, in the coating step, the surface of the core is coated with Teflon in the coating step.

[0017]

According to the first aspect of the present invention, there is provided a linear solenoid according to a first aspect of the present invention, wherein an outer peripheral wall of the core of the hollow cylindrical body constituting a part of the magnetic circuit is coated with an electrically insulating material. Since the coil winding is wound directly on the outer peripheral wall of the core on which the layer is formed, it is possible to eliminate the need for a bobbin, reduce the number of parts, and reduce the size in the radial direction.

In the linear solenoid according to the second aspect of the present invention, the inner peripheral wall of the core is coated with a lubricating material to form a lubricating material layer. The bearings and support members are not required, so that the number of parts is reduced and the size in the radial direction is reduced.

A linear solenoid according to a third aspect of the present invention having the above-mentioned structure is the linear solenoid according to the second aspect, wherein the electrically insulating material layer coated on the outer peripheral wall of the core and the lubricating material layer coated on the inner peripheral wall of the core are provided. Since both are made of the same resin material, it is possible to reduce the number of types of resin material for coating, thereby facilitating maintenance and reducing costs.

In the linear solenoid according to a fourth aspect of the present invention, the winding of the coil is directly wound around the concave portion formed in a portion including the axial center of the outer peripheral wall of the core. Therefore, there is an effect that the winding of the coil winding is facilitated and the position of the wound coil winding is stabilized.

In the linear solenoid according to the fifth aspect of the present invention, the bearing portion is formed by projecting radially inward both end portions of the inner peripheral wall of the core in the fourth aspect. Since the shaft is supported, the eccentricity of the shaft is prevented, and the contact area is reduced to suppress the sliding resistance. Therefore, the effect of smoothly and reliably performing the sliding of the shaft and the operation of the linear solenoid. To play.

A linear solenoid according to a sixth aspect of the present invention having the above-mentioned structure, according to the third aspect, wherein the electrically insulating material layer coated on the outer peripheral wall of the core and the lubricating material layer coated on the inner peripheral wall of the core. Since both are made of Teflon, only Teflon can be used as the resin material for the coating, so that maintenance is facilitated and the cost is reduced.

In the linear solenoid according to the seventh aspect of the present invention, the coil is covered with an electrically insulating material in the third aspect of the invention, so that the coil is insulated from the outside and the coil is wound. This has the effect of preventing collapse.

The manufacturing method of the linear solenoid according to the eighth aspect of the present invention, wherein the surface of a core constituting a part of a magnetic circuit is coated with a resin material, and a coil winding is wound directly around the outer periphery of the core, Since the coil is coated with a coating material, it eliminates the need for bobbins, reduces the number of parts, and enables the manufacture of linear solenoids that have a compact radial size.
This has the effect of reducing processing man-hours, increasing efficiency for mass production, and reducing costs.

According to a ninth aspect of the present invention, in the method of manufacturing a linear solenoid according to the ninth aspect, since a necessary portion of the core whose surface is coated with a resin material is processed, the number of processing steps is reduced. It works.

In the method for manufacturing a linear solenoid according to a tenth aspect of the present invention having the above structure, the surface of the core is coated with Teflon in the ninth aspect of the invention. This has the effect of minimizing the sliding resistance.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) As shown in FIGS. 1 to 3, the linear solenoid according to the first embodiment comprises a pressure regulating valve 1 and a thrust generator 2, and a magnetic circuit in the thrust generator 2. A hollow cylindrical core 21 constituting a part of
An electric insulating material layer 241 formed by coating an outer peripheral wall of the core 21 with an electric insulating material; a coil 22 having a winding wound directly on the outer peripheral wall of the core 21 having the electric insulating material layer formed thereon; A lubricating material layer 242 formed by coating a lubricating material on the inner peripheral wall of the core 21
And a shaft 23 slidably disposed inside the core 21 on which the lubricating material layer is formed and connected to the spool 11 of the pressure regulating valve unit 1.

The spool valve constituting the pressure regulating valve section 1 is
Supply port 10 for supplying supply pressure as shown in FIG.
1, a valve sleeve 10 having an output port 102 for supplying an adjusted output pressure, a discharge port 103 for discharging pressurized oil, and a feedback port 104 for feeding back the output pressure. The spool 11 has an inserted spool 11 and a spring 12 as an elastic member inserted between the receiving plug 13 mounted on the valve sleeve 10 and the spool 11 to urge the spool 11 rightward in the drawing. .

The supply pressure is adjusted to the output pressure corresponding to the electric signal input to the thrust generating unit 2 by balancing the load by the thrust generating unit 2, the load by the spring 12, and the output pressure feedback load. It is configured to be supplied.

As shown in FIG. 1, the thrust generating unit 2 coaxially inserts a hollow cylindrical core 21 having a substantially T-shaped cross section into a magnetic hollow cylindrical cover 20 provided with a connector 201. The flange portion 211 at one end is integrally fitted to one end of the cover 20 together with one end of the valve sleeve 10.

The outer peripheral wall 212 of the core 21 is coated with Teflon, a resin material of the same material, to form an electrically insulating material layer 241. The inner peripheral wall 213 of the core is coated with Teflon, a resin material of the same material, and lubricated. A material layer 242 is formed.

That is, as the coating material,
A fluororesin represented by Teflon (registered trademark of DuPont, polytetrafluoroethylene), molybdenum disulfide, or the like can be used.

In particular, as the resin constituting the lubricating material layer 242 coated on the inner peripheral wall 213 of the core,
Other components can be mixed according to heat resistance, abrasion resistance, oil resistance and other use environments.

In addition to the above-mentioned coating material, any material that has a small friction coefficient and can withstand the use environment can be used as a condition for satisfying the performance as a bearing, and Teflon, a low friction material, is optimal.

A concave portion 214 is formed in a portion of the core 21 including the center of the outer peripheral wall 212 in the axial direction, in which the winding of the coil is directly wound.

That is, the depth h of the concave portion 214 is
Since it is important to accurately wind the first layer in order to align and wind the coil windings with high precision as shown in FIG. 5, the coil diameter is set to be larger than 1/2 of the wire diameter D of the coil windings. By doing so, the coil winding can be securely inserted into the recess 21.
4 can be easily rolled by pressing against the wall of the step portion.

However, as the depth h of the recess 214 increases, the surface area of the air gap with the mover increases, so that the suction force level tends to decrease. It is necessary to determine in consideration of.

A concave portion (depth d) is formed in a portion including the center in the axial direction of the inner peripheral wall of the core so that both end portions protrude inward in the radial direction. A bearing portion 215 that supports the shaft in contact therewith is formed.

Since the inner peripheral wall 213 of the core is coated with Teflon and the lubricating material layer 242 is formed, the variation in the coating thickness of the lubricating material layer 242 and the coating material when the pressing force of the shaft 23 is maximized. It is necessary to set the coating material corresponding to the concave portion between the bearing portions 215 so as not to contact the shaft 23 in consideration of the bending of the shaft portion 23.

That is, as shown in FIGS. 3A and 3B, since the coating thickness of the lubricating material layer 242 has a variation (wave-like unevenness), the lubricating material layer 242 has the above-mentioned unevenness in the coating thickness in the concave portion. It comes into contact with the shaft 23.

Even when machining the inner diameter of the bearing portion 215, it interferes with the convex portion of the coating thickness in the concave portion, so that the bearing portion 215 cannot be reliably supported.

In the coil 22, a coil winding is directly wound around the concave portion 214 formed in a portion including the axial center of the outer peripheral wall of the core 21 on which the electrically insulating material layer of the Teflon is formed.

The coil in which the coil winding is wound directly on the recess 214 is covered with an electrically insulating material so that the coil does not directly contact the outside, and the wound coil winding is positioned. It is configured to be.

In the linear solenoid of the first embodiment having the above structure, the outer peripheral wall 212 of the core 21 is coated with an electrically insulating material, and the electrically insulating material layer 241 is formed.
Since the coil winding is wound directly around the outer peripheral wall 212 of the core 21 having the above-described structure, the conventional bobbin is not required, the number of components is reduced, and the size in the radial direction is reduced.

The linear solenoid of the first embodiment is
Since the inner peripheral wall of the core 21 is coated with a lubricating material to form a lubricating material layer 242, the shaft 2
3 is slidably disposed on the inner peripheral wall of the core 21, so that conventional bearings, bushes and other bearings and supporting members are not required, the number of parts is reduced, and the size in the radial direction is reduced. To play.

Further, in the linear solenoid of the first embodiment, the electrically insulating material layer 241 coated on the outer peripheral wall of the core 21 and the lubricating material layer 242 coated on the inner peripheral wall of the core 21 are both made of the same material. Since it is made of Teflon, which is a resin material of the above, it is possible to reduce the number of types of resin material for the coating, thereby facilitating maintenance and reducing costs.

Particularly, since the lubricating material layer 242 coated on the inner peripheral wall of the core 21 is made of Teflon, which is a low friction material, the shaft 23
This effectively reduces the sliding resistance and smoothes the movement.

The linear solenoid of the first embodiment is
Since the winding of the coil 22 is directly wound around the concave portion 214 formed in the portion including the center in the axial direction of the outer peripheral wall of the core 21, the winding of the coil winding is facilitated, and the wound coil is wound. This has the effect of stabilizing the position of the coil winding.

That is, since the depth of the concave portion 214 is set to be larger than one half of the wire diameter D of the coil winding, the coil winding is surely formed on the wall of the step portion of the concave portion 214. It can be rolled easily by pressing and rolling.

Further, in the linear solenoid of the first embodiment, the bearing portion 215 is formed by projecting both axial end portions of the inner peripheral wall of the core 21 inward in the radial direction.
Supports the shaft 23, so that the shaft 2
In order to prevent the eccentricity of No. 3 and to reduce the contact area to suppress the sliding resistance, there is an effect that the sliding of the shaft 23 and the operation of the linear solenoid are smoothly and reliably performed.

The linear solenoid of the first embodiment is
Since the coil 22 is covered with the electrically insulating material, it is possible to achieve an effect of achieving insulation between the coil 22 and the outside and preventing collapse of the coil.

(Second Embodiment) The method for manufacturing a linear solenoid according to the second embodiment is related to the method for manufacturing a linear solenoid according to the first embodiment described above, as shown in FIG.

In the manufacturing method of the linear solenoid according to the second embodiment, the entire surface of the core 21 (only the upper half is shown in FIG. 4) constituting a part of the magnetic circuit is coated with Teflon as a resin material.

As shown in FIG. 4B, a cutting process is performed to remove the Teflon of the necessary portions 21A, 21B, and 21C of the core 21 whose entire surface is coated with Teflon.

As shown in FIG. 4C, the coil 22
The coil winding is directly wound around the concave portion 214 on the outer periphery of the core 21 using a jig to form the core 21.

As shown in FIG. 4D, the coil 22 wound around the recess 214 on the outer periphery of the core 21 is coated with a coating material in order to insulate it from the outside and prevent the coil from collapsing. , And resin molding.

In the method of manufacturing a linear solenoid according to the second embodiment having the above structure, the outer surface of the core 21 is coated with Teflon, and a coil winding is wound directly around the outer peripheral wall of the core 21 coated with Teflon. This eliminates the need for bobbins, reduces the number of parts, and enables the manufacture of a linear solenoid that has a compact size in the radial direction. In addition, the number of processing steps is reduced, the efficiency for mass production is increased, and the cost is reduced.

In the method for manufacturing a linear solenoid according to the second embodiment, the coil 22 wound directly around the outer peripheral wall of the core 21 is covered with a coating material, so that insulation from the outside is realized and the coil is wound. This has the effect of preventing collapse.

Further, in the method of manufacturing the linear solenoid according to the second embodiment, since a necessary portion of the core 21 whose surface is coated with the Teflon is processed, an effect of reducing the number of processing steps can be obtained.

In the method for manufacturing a linear solenoid according to the second embodiment, since the entire surface of the core 21 is coated with Teflon by a single coating process, the coil 22
And the core 21 can be insulated, and the sliding resistance of the shaft 23 can be minimized.

(Third Embodiment) A linear solenoid according to a third embodiment of the present invention and a method of manufacturing the same include an electrically insulating material layer 241 formed on the outer peripheral wall of the core 21 and a lubrication formed on the inner peripheral wall of the core 21. While the material layer 242 is coated with the same resin material, the electrical insulating material layer 241 formed on the outer peripheral wall of the core 21 and the inner peripheral wall of the core 21 are formed as shown in FIG. The difference is that the lubricating material layer 242 is coated with a different material, and the following description will focus on the difference.

That is, as shown in FIG. 5A, inexpensive polyethylene (PE) or polyvinyl chloride (P) other than Teflon is provided in the concave portion 214 of the outer peripheral wall of the core 21.
A resin such as VC), an enamel or another electric insulating material is selectively coated to form an electric insulating material layer.

As shown in FIG. 5B, bearing portions 215 protruding radially inward at both axial ends of the inner peripheral wall of the core 21 are similar to those in the first and second embodiments. Coated with Teflon, lubricating material layer 242
To form

In the linear solenoid according to the third embodiment and the method of manufacturing the same, the outer peripheral wall of the core 21 is coated with an electric insulating material, and is directly wound around the outer peripheral wall of the core on which the electric insulating material layer is formed. Since the electrical insulation between the coil winding and the core 21 is realized, there is an effect that a bobbin is not required, the number of components is reduced, and the size in the radial direction is reduced.

The linear solenoid according to the third embodiment and the method of manufacturing the same are characterized in that the concave portion 214 of the outer peripheral wall of the core 21 is provided.
Inexpensive materials such as polyethylene (PE) or polyvinyl chloride (PVC) other than the above-mentioned Teflon are selectively coated with an enamel or other electric insulating material to form an electric insulating material layer. Since the coating is performed only on the essential parts, it is possible to reduce the amount of the electrically insulating material used and to reduce the cost.

Further, in the linear solenoid according to the third embodiment and the method of manufacturing the same, the lubricating material is coated on the inner peripheral wall of the core 21 to form the lubricating material layer.
The shaft 23 is slidably supported by the inner peripheral wall of the core 21 on which the lubricating material layer is formed.
This eliminates the need for a support member, reduces the number of parts, and reduces the size in the radial direction.

Further, in the linear solenoid of the third embodiment and the method of manufacturing the same, since Teflon is coated only on the bearing portion 215, the amount of expensive Teflon used as a lubricating material can be reduced and the cost can be reduced. This has the effect of

The above-described embodiments are exemplarily described for explanation, and the present invention is not limited to these embodiments. Those skilled in the art will recognize from the claims, the detailed description of the invention, and the drawings. Modifications and additions are possible without departing from the technical idea of the present invention.

In the above-described embodiment, an example has been described in which both the electric insulating material and the lubricating material are made of a synthetic resin material. However, the present invention is not limited to these, and the electric insulating material and the lubricating material are not limited thereto. Inorganic materials can be used as long as they have properties.

In the above-described embodiment, an example in which a concave portion for winding a coil winding is formed on the outer peripheral wall of the core has been described as an example. However, the present invention is not limited to such a case. As shown in FIG. 6, a mode in which a ring-shaped plate is provided at one end of the outer peripheral wall of the core and a coil winding is wound between the plate and the flange portion of the core can be adopted.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a linear solenoid according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view illustrating a concave portion formed on an outer peripheral wall of a core in the linear solenoid according to the first embodiment.

FIG. 3 is a partial cross-sectional view illustrating a concave portion and a bearing portion formed on an inner peripheral wall of a core in the linear solenoid according to the first embodiment.

FIG. 4 is a partial cross-sectional view for explaining each step of a method for manufacturing a linear solenoid according to a second embodiment of the present invention.

FIG. 5 is a partial cross-sectional view for explaining each step of a linear solenoid according to a third embodiment of the present invention and a method of manufacturing the same.

FIG. 6 is a cross-sectional view showing another embodiment of the present invention.

FIG. 7 is a sectional view showing a conventional linear solenoid.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure regulating valve part 2 Thrust generating part 21 Core 22 Coil 23 Shaft 241 Electric insulating material layer 242 Lubricating material layer

Claims (10)

[Claims] 1. A core of a hollow cylindrical body constituting a part of a magnetic circuit, an electric insulating material layer formed by coating an outer peripheral wall of the core with an electric insulating material, and the electric insulating material layer is formed. A linear solenoid comprising: a coil having a winding wound directly around an outer peripheral wall of the core; and a shaft slidably disposed inside the core. 2. The linear solenoid according to claim 1, wherein a lubricating material is coated on an inner peripheral wall of the core to form a lubricating material layer. 3. The electrical insulating material layer according to claim 2, wherein the electrically insulating material layer coated on the outer peripheral wall of the core and the lubricating material layer coated on the inner peripheral wall of the core are both made of the same resin material. A linear solenoid. 4. The linear solenoid according to claim 3, wherein a concave portion in which a winding of the coil is directly wound is formed in a portion including an axial center of an outer peripheral wall of the core. 5. The linear solenoid according to claim 4, wherein axial end portions of the inner peripheral wall of the core protrude radially inward, and a bearing portion for supporting the shaft is formed. . 6. The structure according to claim 3, wherein the electrically insulating material layer coated on the outer peripheral wall of the core and the lubricating material layer coated on the inner peripheral wall of the core are both made of Teflon. And a linear solenoid. 7. The linear solenoid according to claim 3, wherein the coil is covered with an electrically insulating material. 8. A step of coating a surface of a core constituting a part of a magnetic circuit with a resin material; a step of directly winding a coil winding around an outer periphery of the core; and covering the wound coil with a coating material. And a process for producing a linear solenoid. 9. The method for manufacturing a linear solenoid according to claim 8, further comprising a step of processing a required portion of the core having the surface coated with a resin material. 10. A method for manufacturing a linear solenoid, wherein in the coating step according to claim 9, the surface of the core is coated with Teflon.