JPH0831388B2 - Method for manufacturing coil assembly - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to solve the following problems.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a coil assembly, and more specifically, a coil assembly element including a wound iron core having a square cross section and a coil provided inside thereof is provided in a molding die. The present invention relates to a method of manufacturing a coil assembly by molding with a molding resin that is press-fitted.

(Prior Art) In this type of manufacturing method, the molding resin that is press-fitted into the molding die flows through the gap between the inner surface of the molding die and the coil assembly element to fill each part. Since the larger the gap is, the lower the resistance against the flow of the molding resin is, the molding resin tends to easily enter the inside of the wound iron core having a square cross section. When the molding resin first enters the inside of the wound core in this manner, the molding resin pushes the wound core outward. Therefore, the gap between the outer surface of the wound core and the inner surface of the molding space becomes narrow, and it becomes difficult for the resin to flow into the space. As a result, there has been a problem that the coating on the outside of the wound core becomes thin, or a part of the coating is left uncoated, and a defective product is often produced.

(Problems to be Solved by the Invention) Except for the above-mentioned conventional problems, the present invention aims to fill the gap inside the winding core with the molding resin earlier than filling the gap outside the winding core with the molding resin. By blocking
It is an object of the present invention to provide a method for preventing a wound core from bulging outward so that a coil assembly having a proper coating on the outside of the wound core can be manufactured.

 The configuration of the present invention is as follows.

(Means for Solving Problems) The invention of the present application employs means as described in the claims, and its operation is as follows.

(Operation) When the molding resin is press-fitted into the molding space in the molding die, the resin flows into the gap on the outer side of the wound core and also flows toward the inner side of the wound core. The presence of the raised plate causes flow resistance to the molding resin flowing toward the inside of the wound core. As a result, it is possible to prevent the filling of the molding resin into the gap inside the wound core faster than the filling of the molding resin into the gap outside the wound core.

(Example) Hereinafter, drawings showing an example of the present application will be described. First
1 to 10, 1 is a mold, 4 is a coil assembly element, and 5 is a raised plate. The molding die 1 includes a first die 2 and a second die 3. In this example, the first mold is the fixed mold and the second mold is the movable mold, but the relationship may be reversed. In the first mold 2, 10 is a concave molding space, and 10a is its inner surface. The molding space 10 has a molding space 11 for molding the body of the coil assembly and a molding space 12 for molding the plug holding portion. on the other hand,
On the inner surface of the second mold 3 facing the molding space 10, 13 is a molding surface for forming a contact surface of the coil assembly with respect to the valve, 14 is a positioning rod for positioning the coil assembly element 4, It also serves to form a space for inserting the tube assembly in the coil assembly. Reference numeral 15 indicates a convex portion for forming a concave portion for retaining the collar. Next, 16 is a press-in port for molding resin provided in the second mold 3, 17 is a runner, and 18 is a gate. The gate 18 is provided on the convex portion 19 provided on the inner surface. As is well known, this prevents the bulging portion remaining at the place where the resin is press-fitted in the molded coil assembly from interfering with the fact that the valve attachment surface of the coil assembly can be attached exactly to the valve body. It is a part configured for the purpose. Reference numeral 20 denotes a position piece protruding from the inner surface, and a position determining step portion 21 for positioning the raising plate 5 is provided at a position near the tip end portion thereof. Next, in the coil assembly element 4, 23 is a wound iron core, for example, Japanese Patent Laid-Open No. 55-
Similar to the one disclosed in Japanese Patent No. 102217, a number of U-shaped iron core materials formed of high-permeability materials such as iron plates and silicon steel plates each having an insulating surface are stacked to form a cross-sectional shape. It is configured in a square shape. Reference numerals 24, 24 denote through holes formed in the pair of wall surfaces 23a, 23a facing each other in the wound iron core 23. Reference numeral 25 denotes a coil, and the pair of opposing wall surfaces 23a, 23
Between a, the axis of itself is provided so as to match the axis of the through hole 24. The coil 25 is constructed by winding a winding 27 on a bobbin 26, and is provided with a lead wire 28 connected to the winding 27 and a pin 29 for electrical connection connected to the tip thereof.

Next, the raising plate 5 is provided with coil assembly elements so that the distance from the abutment surface 37 (see FIGS. 11 to 14) of the completed coil assembly 7 to the center position of the coil 25 in the axial direction is appropriate. 4 is directed to the axial direction to the left in FIG. 3, and at the same time acts as a diaphragm plate for controlling the inflow of the molding resin into the molding space. It is formed by molding or cutting. As the raised plate 5, the same type as the molding resin described later is used, but other types may be used. In the raised plate 5, 31 is a main body, and a through hole 32 for inserting the positioning rod 14 is formed in the central portion of the main body. The thickness of the main body 31 of the raised plate 5 is
It is preferable to set the size of the gap between the convex portion 19 and the convex portion 19 so as not to prevent the smooth inflow of the molding resin from the gate 18 into the gap. Reference numeral 33 is a through hole for inserting the positioning piece, and 34 is a projecting portion for reinforcing the plug holding portion. 35 is a weir part, and the main body 31
31a for facing the inner surface of the second mold 3 in
Is provided in a protruding shape.

Next, the manufacturing procedure of the coil assembly will be described.
First, with the second mold 3 separated from the first mold 2, the raising plate 5 is positioned with respect to the positioning piece 20.
Next, the coil assembly element 4 is positioned in its through hole 24 by a positioning rod 14
It is attached to the second mold 3 in a state in which is inserted. In this case, as shown in FIG. 7, the surface 4a of the coil assembly element 4 facing the inner surface of the second mold 3 is brought into contact with the raising plate 5 and positioned by the positioning piece 20. Then, the coil assembly element 4 enters the molding space 10 of the first mold 2 and the second mold 3 covers the opening of the molding space of the first mold 2 with respect to the first mold 2 and the second mold 3 Coalesce. As a result, the state shown in FIGS. 2 to 4 is obtained. In this state, on the outer side of the peripheral surface of the wound iron core 23, as shown in FIG.
b and 36c are formed, and gaps 36d and 36e for circulating the molding resin are formed on both end surfaces of the wound core 23, as clearly shown in FIG.

Next, the nozzle of the molding resin press-fitting device is directed to the injection port 16 opening on the upper surface of the molding die, and the molding resin is press-fitted from the press-fitting device as indicated by the arrow a. As the molding resin, a thermosetting resin (epoxy resin, polyester resin, etc.) or a thermoplastic resin (6 nylon G-containing, PBT, PET, etc.) is generally used. A low pressure molding means or an injection molding means is used as the press-fitting means, and the pressure thereof is, for example, about 1000 kg / cm ² . By press-fitting the molding resin as described above, the molding resin is run through the inlet 16 as shown by the arrow B.
It is pushed out through the gates 17 from the upper and lower gates 18 into the molding space 10. The extruded molding material flows toward the gap 36a on the outer side of the winding core as indicated by arrow C, and is opposite to the inner surface of the second die 3 and the coil assembly element 4 on the raised plate 5 as indicated by arrow D. Flows into the gap 36c between the side surface. Further, the molding resin flowing into the gap 36a flows toward the gap 36b or the gaps 36d and 36e. Further, the molding resin flowing into the gap 36c passes through the gap 36c on one side, and then flows into the molding space 12 of the plug holding portion.
To the gap 36d as indicated by arrow E. In this case, the molding resin that smoothly flows between the convex portion 19 and the main body 31 of the raised plate 5 in the gap 36c is
Due to the presence of the weir portion 35 formed so as to surround the convex portion 19 in the raised plate 5, the positioning rod 14 and the lead wire are provided.
It is prevented from rushing to the side of 28 and flows relatively slowly to that side. Therefore, it is possible to prevent the accident that the molding resin soaks between the inner surface of the through hole 24 and the positioning rod 14 in the coil assembly element 4 or the thin lead wire 28 is cut by the molding resin. On the other side, it flows toward the gap 36e as shown by the arrow E '. Further, the molding space 12 and the gaps 36d, 36 of the plug holding portion are
The molding resin flowing in e also flows toward the gap 36f inside the winding core 23 as indicated by the arrow. As the molding resin flows in as described above, the entire circumference of the wound iron core 23 and the entire gap between the winding core 23 and the coil 25 are filled with the molding resin.

In the above case, due to the presence of the raised plate 5, the gap size of the gap 36c is narrowed to increase the flow resistance of the molding resin there. Therefore, the gap 36a is filled with the molding resin at the same time or faster than the gap 36f is filled with the molding resin after passing through the gap 36c. as a result,
The gap 36f is filled earlier with the molding resin than the gap 36a, and there is no effect that the wound iron core 23 is spread outward, and the gap dimension of the gap 36a is appropriately maintained, and the molding resin there is maintained. Is properly filled. The thickness of the main body 31 and the height of the weir 35 in the raised plate 5 are such that the gap dimension of the gap 36c can exert an appropriate flow resistance on the molding resin passing therethrough, so that the gap 36f passes through the gap 36c. It is preferable to experimentally determine that the molding resin is filled at the same time as or later than the filling of the molding resin into the gap 36a.

When the press-fitting of the molding resin as described above is completed, the resin is solidified and then separated from the first mold 2 to the second mold 3 as is well known, and further, the second mold 3 is completed by molding.
The coil assembly 7 having a shape as shown in FIGS. 11 to 13 is removed.

Coil assembly 7 shown in FIGS. 11 to 13 above.
In 37, 37 is an abutting surface for the valve formed by the molding surface 13, 38 is a space for inserting the tube assembly formed by the positioning rod 14, 39 is a recess for retaining the flange formed by the convex portion 15. Show each.

Next, the coil assembly 7 formed as described above is attached to the valve 41, for example, as shown in FIG. 14, so that it functions as an electromagnetic valve. In FIG. 14, 42 is a tube assembly, and 43 is a nut for fixing the coil assembly 7 to the valve 41. In the tube assembly 42, 44 is a fixed iron core, and has a flange 45 for positioning with respect to the valve 41 and a threaded portion 46 for connection. The fixed iron core 44 is formed of a magnetic material such as a corrosion resistant soft magnetic material, electromagnetic stainless steel, and silicon iron. 47 is a fixed iron core 44
It is a hollow cylinder with one end welded, and is made of extremely low magnetic permeability material such as non-magnetic stainless steel. Reference numeral 48 denotes a closing body welded to the other end of the hollow cylinder 47, and the inside is sealed by the fixed iron core 44, the hollow cylinder 47 and the closing body 48. 49 is a push pin for manual operation provided in the closing body 48, and 50 is an O-ring mounted on the push pin for maintaining airtightness. Reference numeral 51 denotes a movable iron core provided in the hollow cylinder 47, which is movable in the vertical direction in FIG. Next, the nut 43 is screwed into the threaded portion 52 formed in a part of the closing body 48, and the coil assembly 7 is pressed toward the valve 41 through the tube assembly 42, and the contact surface of the coil assembly is pressed. The 37 fits snugly against the valve 41. In such a structure, when the coil is energized through the pin 29, the coil generates a magnetic flux, and the magnetic flux causes the movable iron core 51 to move to the fixed iron core.
Adsorbed toward 44. The force is transmitted to the spool of the valve via the valve pin 53, and the valve is opened / closed or switched as is well known.

(Effect of the Invention) As described above, in the present invention, the first mold 2 having the concave molding space 10 is covered with the second mold 3 so as to cover the opening of the concave molding space 10. Moreover, on the inner surface side of the second mold 3, the concave molding space 10 is formed from the inner surface side.
The positioning rod 14 is provided so as to project inward, and the positioning rod 14 supports the coil assembly element 4 while being inserted into the through hole 24 of the coil assembly element 4. While the above coil assembly element 4
The winding iron core 23 having a square-shaped cross section, and a coil 25 provided between the facing wall surfaces 23a, 23a of the winding iron core 23, the through hole 24 is formed in the facing wall surface. And the axis of the coil 25 is aligned with the axis of the through hole 24, and the inner surface 10a of the concave molding space 10 is
With respect to the inner surface of the second mold 3, the winding core 23
Gaps 36a to 36e necessary for the flow of the molding resin 6 are formed on the outer side of the outer peripheral surface and on the side of both end surfaces, and the joining portion of the first die 2 and the second die 3 is formed in the gap. Since the molding resin 6 is press-fitted from above, the molding resin can be filled and fixed to the outer periphery of the coil assembly element, and the inner surface of the second mold is the contact surface forming surface 13 of the coil assembly for the valve and the inner surface thereof. In the tube assembly 42, a convex portion for forming the retaining concave portion 39 of the collar 45 in the tube assembly 42.
On the other hand, on the surface 4a of the coil assembly element 4 facing the inner surface of the second mold, a raised plate 5 formed by a forming means different from the winding core is attached in a superposed manner. By forming the gap 36c having a relatively large flow resistance between the raised plate 5 and the inner surface of the second mold, when the molding resin is press-fitted, the gap 36f inside the wound iron core 23 is not filled with the molding resin. Since it prevents the gap 36a on the outer side of the wound core from being filled earlier than the filling with the molding resin, it is possible to prevent the wound core 23 from bulging in the direction of arrow A in FIG. 12 in advance. is there.

Furthermore, as described above, a gap 36c having a relatively large flow resistance may be formed between the surface of the coil assembly element 4 facing the inner surface of the second mold and the inner surface of the second mold. , The surface 4a of the coil assembly element is
Since the raised plate 5 formed by a forming means other than the wound iron core 23 is polymerized to form a gap having a large flow resistance, the facing surface 31a of the raised plate 5 facing the inner surface is a raised plate. Since it is a simple substance, it is easy to form it into a complicated shape in which the relation with the unevenness provided on the inner surface of the second mold is sufficiently taken into consideration.
It has an epoch-making feature that it is extremely easy to form an appropriate flow resistance.

[Brief description of drawings]

The drawings show the embodiments of the present application. FIG. 1 is a perspective view of a coil assembly element, and FIG. 2 is a horizontal sectional view of a forming die showing a state in which the coil assembly element is installed in a forming die. (The part is also broken), FIG. 3 is a sectional view taken along the line III-III in FIG. 2, and FIG.
FIG. 5 is a sectional view taken along line VV of FIG. 2, and FIG. 6 is VI of FIG.
-VI line sectional view, FIG. 7 is a sectional view taken along line VII-VII of FIG. 6, FIG. 8 is a bottom view of the raising plate, and FIGS.
FIG. 11 is a sectional view taken along line IX-IX, sectional view taken along line XX, FIG. 11 is a longitudinal sectional view of the coil assembly (sectional view taken along line XI-XI in FIG. 12), and FIG. 12 is taken along line XII-XII in FIG. Line sectional view, thirteenth
The figure is a bottom view of the coil assembly, and FIG. 14 is a vertical cross-sectional view of an electromagnet for a solenoid valve using the coil assembly. 1 ... Mold, 2 ... First mold, 3 ... Second mold, 10 ... Molding space, 14 ... Positioning rod, 4 ... Coil assembly element, 23 ... Winding iron core, 25 ... Coil .

Claims (1)

[Claims] 1. A first mold having a concave molding space is covered with a second mold so as to cover an opening of the concave molding space, and the inner surface side of the second mold is the inner surface side. Is provided with a positioning rod projecting into the concave molding space, and the positioning rod supports the coil assembly element in a state of being inserted into the through hole of the coil assembly element. On the other hand, the coil assembly element includes a wound iron core having a square cross section and a coil interposed between the facing wall surfaces of the wound iron core, and the through hole is formed in the facing wall surface. Has been done,
The axis of the coil is aligned with the axis of the through hole, and the inner surface of the concave molding space and the inner surface of the second die are located outside the outer peripheral surface of the wound core and on both end surfaces. A gap necessary for circulation of the molding resin is formed on the side, and the molding resin is press-fitted into the gap from the joining portion of the first mold and the second mold to mold the coil assembly element around the coil assembly element. In a method of manufacturing a coil assembly in which a resin is filled and fixed, an inner surface of the second mold is a surface for forming an abutting surface of the coil assembly with respect to a valve, and an inner surface of the second mold has a protrusion for forming a recess for retaining a collar in a tube assembly. A portion of the coil assembly element facing the inner surface of the second mold,
A raising plate formed by a forming means different from the winding core is attached in a polymerized state, and a gap having a relatively large flow resistance is formed between the raising plate and the inner surface of the second mold, A method for manufacturing a coil assembly, characterized in that, when the molding resin is press-fitted, the filling of the molding resin into the gap inside the winding core is prevented from being faster than the filling of the molding resin into the gap outside the winding core.