JP2640684B2 - Method of manufacturing movable iron core - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electromagnet for an electromagnetic valve used for operating a valve body in an electromagnetic valve, and more particularly to a method for manufacturing a movable iron core in the electromagnet.

[Conventional technology]

2. Description of the Related Art When a movable core is manufactured by integrally fixing a hollow main body portion and a shaft inserted into the aerial portion, a shrink-fitting method is conventionally used.

However, in the above-mentioned conventional method, the main body is heated,
There was a problem that the magnetic characteristics deteriorated. Therefore, in order to eliminate the problem, there has been provided a method of integrating the two by inserting a shaft into the main body portion and then driving the shaft through the shaft in a direction perpendicular to the axial direction thereof. However, in this method, there is a problem that the shaft of the main body and the shaft of the shaft are displaced due to the driving of the pin, and there is a problem that the shaft is bent at a position where the pin is driven. These things make the main part eccentric with respect to the shaft. When the eccentricity is large, when the main part of the electromagnet receives a magnetic force, the attractive force that the main part receives in a direction intersecting with the axis becomes large. Then, the frictional force between the shaft and their bearings increases, and there is a problem that the smooth movement of the movable iron core is hindered.

[Problems to be solved by the invention]

The present invention has been made in view of the above points, and an object of the present invention is to make it possible to easily match the axes of the main body portion and the shaft with each other, and furthermore, to make the thermal change as described above. It is an object of the present invention to provide a method for manufacturing a movable iron core capable of forming a movable iron core without causing mechanical deformation.

[Means for solving the problem]

In order to achieve the above object, the present invention is directed to a hollow cylindrical movable core main body and an inner diameter of the hollow part in which a part is inserted into the hollow part of the main body. Prepare shafts which are formed to have an outer diameter dimension corresponding to the above, and in which a part of the portion to be left in the hollow portion has a small diameter, and insert the shaft into the hollow portion of the main body portion. And applying a liquid or jelly-like adhesive evenly to the outer peripheral surface of the small-diameter portion of the shaft, and inserting the shaft into the hollow portion of the main body in a state where the shaft is inserted. Is cured in the hollow part.

[Action]

Part of the shaft is inserted into the hollow part of the main body. In this case, in the shaft, an adhesive is adhered to the outer peripheral surface of the small-diameter portion provided at the portion facing the inner peripheral surface of the hollow portion. By curing the adhesive, the main body and the shaft are integrated, and the movable iron core is completed.

〔Example〕

Hereinafter, drawings showing an embodiment of the present application will be described. First
In FIG. 2 and FIG. 2, the solenoid valve electromagnet A is mounted on a well-known valve body B to form a solenoid valve. The valve body B has a well-known structure.
Is a liquid path (also referred to as an oil path), 2 is a port, 3 is a spool that can move in the left-right direction in FIG. 1, 4 is a spool return that applies a return force to the spool 3 via a spring seat 5. A spring is provided on both the left and right sides (only the right side is shown in the drawing) of the spool 3 so that the spool 3 is normally positioned at a neutral position as shown at the bottom of FIG. Next, the electromagnet A will be described. The electromagnet A is constituted by a pipe C, an annular coil D disposed around the pipe C, and a cap E for closing the opening of the pipe C and fixing the coil D.

Hereinafter, the pipe body C will be described. Reference numeral 7 denotes a main body. Reference numeral 8 denotes a fixed core portion of the main body, 9 denotes a magnetic conducting portion, each of which is formed of a magnetic material such as pure iron or low-carbon steel, and one end of each is formed of a non-magnetic material, for example, a copper-based metal. And are integrally connected by a magnetic interrupting unit 10. 8a
Denotes a horizontal characteristic forming unit. Numeral 11 denotes a yoke portion provided at one end of the fixed core portion 8 and formed as a single member. The yoke portion is formed in a flange shape and also serves as an attachment portion 12 for attaching the pipe body to the valve body. 13 is a mounting bolt. Reference numeral 14 denotes a fixed core element, which is formed of a magnetic material in the same manner as the fixed core portion 8 and is left inside by press-fitting or clearance fitting. The element 14 forms a fixed core together with the fixed core portion 8.
14a is a liquid flow hole. Reference numeral 15 denotes a bearing held by the fixed core element 14, which is made of a material having low sliding resistance. Reference numeral 16 denotes a spacer for preventing residual magnetism, which is formed of a nonmagnetic material (for example, nonmagnetic stainless steel or brass). Reference numeral 18 denotes a connecting male screw provided on the outer periphery of the main body 7 at a portion facing the cap E. Reference numeral 19 denotes a bearing holder, which also serves as a stopper for the movable iron core, and is formed of a non-magnetic material similarly to the spacer 16 described above. The holder 19 is provided with a liquid flow hole 20. Reference numeral 21 denotes an O-ring for sealing, and reference numeral 22 denotes a bearing held by a holder 19, which is made of a material having low sliding resistance.
Next, reference numeral 23 denotes a movable iron core provided inside the pipe body. Reference numeral 24 denotes a hollow cylindrical main body of the iron core 23,
It is formed of a magnetic material such as low carbon steel. 24a is a liquid circulation hole. Reference numeral 25 denotes a shaft, which is formed of a non-magnetic material (for example, non-magnetic stainless steel), and is supported by bearings 15 and 22 so as to be freely movable in the axial direction. The surface hardness of the shaft 25 is increased in order to increase the wear resistance against sliding with the bearing. The shaft 25 also serves as a transmission piece for transmitting the movement of the movable core main body 24 to the spool 3.

Next, the coil body D will be described. Reference numeral 27 denotes a coil main body, which is configured by winding a coil winding 29 around a bobbin 28. 30 indicates a lead wire. 31 and 32 are yokes provided along one end and the other end of the main body 27, and 33 is a yoke for magnetically connecting the yokes 31, 32, each of which is a magnetic material such as pure iron or low carbon steel. These yokes are made of
31 to 33 constitute an external magnetic circuit. 34 is the main body 27,
A molded body in which the yokes 31 to 33 are integrated, and also serves as a case, and a well-known thermosetting or thermoplastic casting resin having high heat resistance is used. In addition, glass powder may be mixed in order to increase the mechanical strength. Numeral 35 is a bushing for protecting a lead wire lead-out portion.

Next, the cap E will be described. The cap E is formed in a convex shape, 37 indicates a side wall, and 38 indicates a bottom wall. Reference numeral 39 denotes a female screw provided on the inner peripheral surface 37a of the peripheral side wall 37 at a portion facing the pipe body, and is formed so as to correspond to the male screw 18. Reference numeral 37b denotes a coil body pressing portion, which is formed with a distal end portion of the peripheral side wall 37. Reference numeral 40 denotes an O-ring for sealing. Reference numeral 41 denotes an air vent hole, and the bottom wall 38 is opened to the inner peripheral surface 37a.
Is formed at the edge portion. A female screw is formed on the inner peripheral surface of the air vent hole 41, and an opening / closing stopper 42 is screwed therein. 43 is a well-known seal washer, which has an air vent hole 41.
To prevent leakage at night from between the edge of the hole and the head of the opening / closing plug. A pressing member 44 is interposed between the bottom wall 38 and the bearing holder 19 of the pipe body C. For example, a wave washer is used. Reference numeral 45 denotes a locking member interposed between the coil body D and the coil body pressing portion 37b of the cap E, for example, a wave washer.

Next, the manufacture of the movable iron core 23 will be described with reference to FIG. First, the main body 24 and the shaft 25 are respectively manufactured by, for example, lathe processing. A through hole for inserting the shaft, that is, a hollow portion 24b is formed in the center of the main body 24. On the other hand, a small-diameter portion 25a for obtaining a bonding margin 26 is formed in a part of the insertion portion 25 located in the hollow portion 24b in the middle portion of the shaft 25. The outer diameter of the main body 24 is, for example, 18 mm, the length is 30 to 35 mm, the inner diameter D1 of the hollow portion 24b is, for example, 5.990 mm, and the outer diameter D2 of the insertion portion 25b in the shaft 25 is the D1.
Is 5.985 mm, for example, and the gap between the two in the inserted state is about 5 μm (a gap of about 15 μm may be allowed in some cases). Also, the depth of the bonding allowance is 0.1-0.2
The length is about 12 mm.

Next, an adhesive 47 is applied to the small diameter portion 25a of the shaft 25. A heat-curable or room-temperature curable adhesive is used as the adhesive 47. An anaerobic material is preferable for the reason of improving workability. The properties are liquid. Alternatively, a jelly-like material may be used. Next, a part of the shaft 25, that is, a predetermined portion of the intermediate portion is inserted into the hollow portion 24b. Then, the shaft 25 and the main body 24 are relatively rotated, and the hollow portion 24b
The adhesive is evenly distributed in the circumferential direction between the inner peripheral surface 24c of the shaft 25 and the outer peripheral surface 25c of the small-diameter portion facing the inner peripheral surface in the insertion portion 25b of the shaft 25. In the case of an adhesive having high permeability or when the adhesive is applied uniformly, it is possible to spread the adhesive evenly without the above-mentioned rotation.

Next, the main body 24 and the shaft 25 are kept at rest, and the adhesive is cured. In this case, both may be held by a jig. When a thermosetting adhesive is used, heating is performed within a range where the magnetic properties of the main body 24 are not deteriorated and curing of the adhesive is achieved. Thereby, the movable iron core 23 is completed.

The small diameter portion 25b for forming the bonding margin is formed to obtain a sufficiently large bonding strength. The adhesion of the adhesive to the inner peripheral surface of the hollow portion 24b and the outer peripheral surface of the shaft 25
Is inserted into the hollow portion 24b, and as shown in FIG.
4 is provided with an adhesive injection hole 48 penetrating through the hollow portion 24b, and the adhesive 47 is supplied from the injection hole 48 to the small diameter portion 25 of the shaft.
You may pour into a.

Next, the operation of the solenoid valve is as follows. Lead wire 30
When the coil winding 29 is energized through the coil, the magnetic flux generated by the coil winding 29 is transferred to the main portion 24 of the movable core, the fixed core elements 14 and the fixed core portion 8, the yoke portion 11, the yokes 31, 33, 32, and the magnetic conducting portion 9.
Take the path. As a result, the main portion 24 of the movable core receives a suction force toward the fixed core element 14 and the fixed core 8. The movable core 23 is moved toward the fixed core element 14 and the fixed core part 8 by the attraction force, as shown in the upper half of FIG. This moving force is transmitted from the shaft 25 to the sloop 3 and moves the sloop 3 as shown in the figure. Next, when the current supply to the coil winding 29 is cut off, the magnetic flux disappears. Therefore, the movable iron core 23 is moved by the force of returning the spool 3 to the neutral position by the return spring 4 as shown in the lower half of FIG. Back to the correct position.

〔The invention's effect〕

As described above, in the present invention, the hollow portion 24 of the main portion 24
The shaft to be inserted into the shaft b is formed so that the outer diameter D2 of the insertion portion 25b is formed to a size corresponding to the inner diameter D1 of the hollow portion 24b, while a part of the shaft 25 is provided for fixing the combination. Since the adhesive 47 is attached to the outer peripheral surface of the small diameter portion 25a thus formed, the adhesive 47 has a feature that the two peripheral surfaces can be extremely easily bonded.

Moreover, the adhesive can be sufficiently stored in the small-diameter portion 25a, and there is also an effect that highly reliable bonding can be performed without worrying about an accident such as adhesion unevenness due to insufficient adhesive.

Further, if sufficient adhesive can be stored in the small-diameter portion 25a, it is not necessary to apply an adhesive to the outer diameter portion of the other shaft in the insertion portion 25b, and as much as possible corresponding to the inner diameter dimension D1, It has the feature that it can be formed into a large diameter. As a result, there is an effect that the outer periphery of the large diameter portion 25b of the shaft 25 and the inner periphery of the main body portion 24 come into close contact with each other, so that the axes of the two easily match.

[Brief description of the drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a solenoid valve, FIG. 2 is an exploded perspective view, FIG. 3 is an exploded perspective view of a movable core, and FIG. FIG. 6 is a longitudinal sectional view showing another embodiment of the present invention. 23… Movable iron core, 24 …… Main part, 25 …… Shaft, 47…
…adhesive.

Continuation of the front page (72) Inventor Katsuhiro Ohashi 6-10 Ushimaki-cho, Mizuho-ku, Nagoya-shi, Aichi Inside Sanmei Electric Co., Ltd.

Claims (1)

(57) [Claims] 1. A hollow cylindrical movable core main body and an outer diameter corresponding to an inner diameter of the hollow part in order to leave a part inserted into the hollow part of the main part. A step of forming a shaft having a small diameter in a part of the part to be left in the hollow part, and inserting the shaft into the hollow part of the main body part; A liquid or jelly-like adhesive is evenly adhered to the outer peripheral surface of the small-diameter portion, and the adhesive is cured in the hollow portion while the shaft is inserted into the hollow portion of the main portion. A method for manufacturing a movable iron core, comprising performing a process.