JPH05260709A - Molding device for molded motor - Google Patents

Abstract

PURPOSE:To prevent weld lines from being produced in a resin layer by provid ing an opening and closing member and a resin releasing chamber for a forming mold, and switching this opening and closing member over to its closed position at the time of charging resin and to its open position at the time of almost finishing filling the resin. CONSTITUTION:At the time of manufacturing a molded motor, a stator 15 is formed by winding coils 15b on a stator core 15a at first. After that, the first production 12a of a lower mold 12 is fitted to the inner peripheral surface of the stator core 15a by insertion, and the second protrusion 12b is fitted to the inner peripheral surface of the bearing part 17. Then the lower mold 12 and the upper mold 13 are locked, and a plunger 14 is caused to descend and resin in a material storage chamber 11b is charged into a cavity 11a from a gate 11c. On this occasion, an opening and closing member 21 is set at its closed position, and the resin is caused to descend interlocked with the descent of the plunger 14. And, when the inflow hole 21a of the opening and closing member 21 reaches the inside of a resin releasing chamber 19, the resin is pushed out into the resin releasing chamber 19, and the cavity 11a is filled with sound resin by causing the plunger 14 to descend further.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus for a molded motor, in which a resin layer is formed by injecting resin through a gate in a state where a stator is housed in a cavity of a molding die. Regarding

[0002]

2. Description of the Related Art A conventional structure of a molding apparatus for a molding motor of this type will be described below with reference to FIGS.

First, in FIG. 8, a molding die 1 is a lower die 2.
And an upper mold 3 which is in contact with this and forms a cavity 1a, a material storage chamber 1b and a gate 1c,
It is generally called a transfer mold.

The inner peripheral surface of the stator 4 formed by winding the coil 4b around the stator core 4a is fitted in the first convex portion 2a of the lower mold 2, and the second convex portion 2b is fitted in the inner peripheral surface of the stator 4. The inner peripheral surface of the bearing support member 5 is fitted, and the convex portion 3a of the upper die 3 is pressed against the upper surface of the bearing support member 5. By moving the plunger 6 downward in this state, Material storage room 1b
The resin inside is injected into the cavity 1a through the gate 1c, so that the resin layer 7 covering the stator 4 and the bearing support member 5 is formed.
(See FIG. 10).

According to the above construction, the mold stator 8 as a molded product as shown in FIGS. 9 and 10 is formed. In the figure, a rotor iron core (not shown) of the rotor is housed in the magnetic space portion 8a corresponding to the first convex portion 2a, and a rotation shaft (not shown) of the rotor has a second It is supported via a bearing (not shown) in the hole 5a of the bearing support member 5 corresponding to the convex portion 2b, and is led out of the resin layer 7 through the insertion hole 5b.

[0006]

However, in the above-mentioned conventional structure, the weld line 9 is formed in the resin layer 7 as shown in FIGS. 9 and 10.

That is, as shown in FIG. 11, the resin injected into the cavity 1a is guided by the stator 4 and divided in both directions A and B along the outer peripheral surface thereof (not shown). , The resin is the first protrusion 2a and the bearing support member 5
The outer peripheral surface is also divided in the same manner as in FIG. 11). The weld line 9 is formed after that, on the side opposite to the gate 1c, the tips of the divided resins collide with each other to be in a non-fusion state.

As is well known, among the resins flowing in the cavity 1a, the resin located at the tip of the flow is prone to deterioration due to curing and burning, and the resin injected in the cavity 1a is present. Impurities such as generated gas, dust, and release agent are easily entrained, and therefore, deteriorated resin and resin containing impurities are concentrated at the contact portion between the resins flowing in both directions of the arrows A and B. To do.

That is, the weld line 9 is not only a contact portion between the resins flowing in two opposite directions, but also a focusing portion for the deteriorated resin and the resin containing impurities. Therefore, the weld line 9 is formed in the resin layer 7. When the weld line 9 is formed, not only the appearance of the mold stator 8 is deteriorated and the commercial value is lowered, but also the probability of the occurrence of cracks at the same portion becomes very high.

Therefore, various attempts have been made to solve the above problems, but in any case, it is hard to say that it is perfect.

For example, the molding die 1 is provided with a resin escape chamber located on the opposite side of the gate 1c and communicating with the inside of the cavity 1a, and the contact portion between the resins flowing in both directions of arrows A and B is defined as By letting it escape into the resin escape chamber, the resin layer 7
There is an attempt to prevent the weld line 9 from being formed in this case, but in this case, the resin escape chamber is filled with a sound resin before the weld line 9 is formed.
The contact portion forming the weld line 9 cannot be missed.

In addition to this, by setting the molding conditions, for example, the injection speed of the resin to be high, the hardening and burning of the resin located at the front end of the flow is reduced as much as possible, and the weld line 9 is not erased. However, there has been an attempt to improve the strength of the weld line 9, but in this case, friction and compression between the wires of the coil 4b are promoted as the resin injection speed increases, and the coil 4b is accelerated. Layer short-circuiting easily occurs.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent a weld line from being formed in a resin layer and to prevent the occurrence of a layer short circuit of a coil accompanying it. It is to provide a molding device for a molding motor.

[0014]

According to a first aspect of the invention, a resin layer covering the stator is formed by injecting a resin through a gate in a state where the stator is housed in a cavity of a molding die. In the mold, a resin escape chamber is provided on the molding die on the side opposite to the circumferential direction of the gate and communicates with the inside of the cavity, and the resin escape chamber is provided with an open position for establishing communication between the resin escape chamber and the inside of the cavity. And an opening / closing member that can be switched between a closed position where the resin is not connected and a closing position where the resin is injected into the cavity and the open position when the cavity is substantially filled with the resin. It is characterized by the fact that

According to a second aspect of the present invention, a resin layer covering the stator is formed by injecting a resin through a gate in a state where the stator is housed in the cavity of the molding die. An auxiliary gate that is in communication with the gate and that is in communication with the gate while being spaced apart from the gate in the circumferential direction, and that is in an open position that allows the auxiliary gate to communicate with the inside of the cavity; An opening / closing member that can be switched between a closed position that is in a non-communication state is provided, and the opening / closing member is set to the closed position when the resin is injected into the cavity and to the open position when the resin is substantially filled in the cavity. The feature is that it is done.

[0016]

According to the first aspect of the present invention, when resin is injected into the cavity through the gate with the opening / closing member in the closed position, the resin is diverted by the stator or the like, and the tips of the diverted resin are injected. The gates come into contact with each other on the opposite sides in the circumferential direction of the gate, and become a non-fusion state.

When the cavity is substantially filled with the resin, pressure is applied to the resin. At that time, if the opening / closing member is switched to the open position, the resin in the cavity, The gate located on the opposite side in the circumferential direction, that is, the contact portion between the resins can be extruded into the resin escape chamber.

According to the second aspect of the invention, when the opening / closing member is switched to the open position when the cavity is substantially filled with the resin, the resin is injected from the auxiliary gate into the cavity,
The injection resin disperses the contact portion between the resins.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

First, in FIG. 1, the molding die 11 is composed of a lower die 12 and an upper die 13 which is joined to the lower die 12 to form a cavity 11a, a material storage chamber 11b and a gate 11c. This mold 11 is generally called a transfer mold, and the resin in the material storage chamber 11b is injected into the cavity 11a through the gate 11c as the plunger 14 is lowered. Is becoming

A cavity 11 is formed on the inner bottom surface of the lower mold 12.
The 1st convex part 12a which protrudes in a is provided. The first convex portion 12a is arranged so that the outer peripheral surface thereof is orthogonal to the extending direction of the gate 11c, and the coil 15b is attached to the stator core 15a of the first convex portion 12a. Inner surface of the stator 15, that is, the stator core 15
When the inner peripheral surface of a is fitted and the plunger 14 is lowered, the resin is injected into the cavity 11a from a direction orthogonal to the outer peripheral surface of the stator core 15a.

A second convex portion 12b having a smaller diameter than the first convex portion 12a is provided at the upper end portion of the second convex portion 12a.
The inner peripheral surface of the bearing support member 17 for supporting the rotor 16 (see FIG. 5) is fitted to the convex portion 12b.

The upper mold 13 is provided with a convex portion 13a protruding into the cavity 11a, and the lower mold 12 and the upper mold 1 are provided.
When the molds 3 and 3 are clamped, the lower surface of the convex portion 13a is pressed against the upper surface of the bearing support member 17.

Thus, in a state where the stator 15 and the bearing support member 17 are fitted in the convex portions 12a and 12b, respectively,
As described later, the resin filled in the cavity 11a is solidified to form a resin layer 18 (see FIG. 4) that covers the stator 15 and the bearing support member 17.

By the way, the parting surface of the lower mold 12 is engraved with a space 12c having a substantially L-shaped cross section which communicates with the inside of the cavity 11a, and when the lower mold 12 and the upper mold 13 are clamped together. , The upper opening of the space 12c is the upper mold 13
The resin escape chamber 19 is formed so as to be closed by the parting surface. As shown in FIG. 1, the resin escape chamber 19 is arranged at a substantially middle portion in the height direction inside the cavity 11a, and as shown in FIG. 2, it is arranged on the opposite side in the circumferential direction from the gate 11c. ..

As shown in FIG. 1, the molding die 11 has:
A groove 20 is formed to penetrate the lower mold 12, the resin escape chamber 19, and the upper mold 13. A plate-shaped opening / closing member 21 (see FIG. 3) having a resin inflow hole 21a is accommodated in the groove portion 20, and the opening / closing member 21 is configured to be lowered in conjunction with the lowering of the plunger 14. Accordingly, the resin escape chamber 19 and the cavity 11a can be switched between an open position in which they communicate with each other and a closed position in which they do not communicate with each other.

That is, when the plunger 14 descends and resin is being injected into the cavity 11a, the opening / closing member 21 is at the closed position where the resin inflow hole 21a is above the resin escape chamber 19, and the cavity 11a is closed. The inside and the inside of the resin escape chamber 19 are brought into a non-communication state. Also, the plunger 14
In the state where the resin is further filled in the cavity 11a, the opening / closing member 21 of the opening / closing member 21 reaches the open position where the resin inflow hole 21a corresponds to the inside of the resin escape chamber 19 and the inside of the cavity 11a and the resin escape chamber. The inside of 19 is brought into communication.

In addition, from the state where the cavity 11a is substantially filled with the resin to the state where the resin is completely filled,
The resin inflow hole 21a is formed in a square hole shape in consideration of the movement amount of the opening / closing member 21 so that the inside of the cavity 11a and the inside of the resin escape chamber 19 are always in communication with each other.

Next, the operation of the above configuration will be described.

First, the coil 15b is wound around a slot (not shown) of the stator core 15a to form the stator 15, and the lower die 12 and the upper die 13 are opened, and the first convex portion 12a is formed. When the inner peripheral surface of the stator core 15a is fitted,
The inner peripheral surface of the bearing support member 17 is fitted to the convex portion 12b of the above, and the lower die 12 and the upper die 13 are clamped.

Next, the plunger 14 is moved downward,
Resin (premix, phenol, epoxy, etc.) in the material storage chamber 11b is injected into the cavity 11a through the gate 11c. In this state, the opening / closing member 21 is in the closed position, but thereafter, the opening / closing member 21 descends in conjunction with the lowering of the plunger 14.

The resin injected into the cavity 11a is
As shown in FIG. 2, the stator 15 is guided and shunted in both directions A and B along the outer peripheral surface of the stator 15 (not shown, but the resin is the outer periphery of the first convex portion 12a and the bearing support member 17). The flow is divided by the surface as in the case of FIG. 2), the gate 11
On the side opposite to c in the circumferential direction (near the resin escape chamber 19), the tips of the divided resins, that is, deteriorated resin,
Resins containing impurities collide with each other, resulting in a non-fusion state.

Then, the plunger 14 is further lowered, and the resin is substantially filled in the cavity 11a.
When a pressure is applied to the resin in a, the resin inflow hole 21a reaches the inside of the resin escape chamber 19 and the cavity 11
The inside of a and the inside of the resin escape chamber 19 are in communication with each other. Then,
As shown by the arrow C, the resin located in the abutting portion is
The resin corresponding to the amount of the resin extruded into the resin escape chamber 19 is filled by being extruded into the resin escape chamber 19 and further lowering the plunger 14, and the cavity 11a is filled with sound resin.

After that, the resin filled in the cavity 11a is solidified to form a resin layer 18 as shown in FIG. 4, and the lower mold 12 and the upper mold 13 are opened to form a molded product. The mold stator 22 is taken out, and the cold slug 23 corresponding to the gate 11c and the cold slug 24 corresponding to the resin escape chamber 19 are cut off from the two-dot chain lines D and E of the mold stator 22, respectively.

Next, as shown in FIG. 5, the first convex portion 12
The rotor core 16a of the rotor 16 is housed in the magnetic space 22a of the stator core 15a corresponding to a, and the one end 16c of the rotary shaft 16b is formed in the hole of the bearing support member 17 corresponding to the second protrusion 12b. 17a is inserted through a ball bearing 17c and is led out of the resin layer 18 through an insertion hole 17b. The other end 16d of the rotating shaft 16b is attached to the bearing support member 17a.
While being supported by a ball bearing (not shown) held by a bearing bracket (not shown) corresponding to the above, the lower surface opening of the mold stator 22 is closed by the bearing bracket.

According to the above configuration, the following effects can be obtained.

That is, the molding die 11 is provided with a resin escape chamber 19 and an opening / closing member 21, and the opening / closing member 21 is connected to the cavity 11a.
When the resin is injected into the inside, the cavity 11a and the inside of the resin escape chamber 19 are set to the non-communication state by setting the closed position, and when the cavity 11a is substantially filled with the resin, the opening position is set to the communicating position. Since the resin can be switched in such a manner that the resin located inside the cavity 11a on the opposite side of the gate 11c, that is, the resin that has deteriorated and the resin that contains impurities is contained in the resin escape chamber 1.
9 will be extruded.

Therefore, if the plunger 14 is further lowered from the above state, the inside of the cavity 11a will be filled with the sound resin, and the formation of the weld line in the resin layer 18 can be prevented. Mold stator 2
2) Deterioration of commercial value due to deterioration of appearance and resin layer 18
It is possible to prevent the occurrence of cracks.

Moreover, since it is not necessary to set the resin injection speed to a high value, it is possible to prevent a layer short circuit from occurring in the coil 15b of the stator 15.

Further, in this case, since the resin in the cavity 11a, which is mainly located in the contact portion between the resins, can be extruded into the resin escape chamber 19, the volume of the resin escape chamber 19 is reduced. Even if it is relatively small, there is no problem, and the amount of injected resin can be reduced accordingly, and the cost increase of the mold stator 22 can be suppressed.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.
Only different parts will be described.

That is, the molding die 11 is provided with an auxiliary gate 25 located on the opposite side to the gate 11c in the circumferential direction and communicating with the inside of the cavity 11a. The auxiliary gate 25 is a runner 26 branched from the gate 11c. Through gate 11
It is connected to c.

An opening / closing member 21 is arranged in the auxiliary gate 25. The opening / closing member 21 keeps the plunger 14 moving downward while resin is being injected into the cavity 11a.
The resin inflow hole 21a is located at the closed position above the auxiliary gate 25, and the inside of the cavity 11a and the inside of the auxiliary gate 25 are not communicated with each other. When the plunger 14 further descends and the cavity 11a is substantially filled with the resin, the opening / closing member 21 of the opening / closing member 21 reaches the opening position where the resin inflow hole 21a corresponds to the inside of the auxiliary gate 25 and the cavity 11a.
The inside and the inside of the auxiliary gate 25 are brought into communication with each other.

According to the above construction, with the opening / closing member 21 in the closed position, the cavity 11 is passed through the gate 11c.
When the resin is injected into a, the resin is shunted by the stator 15, and the tips of the shunted resins abut each other on the opposite side in the circumferential direction of the gate 11c, resulting in a non-fusion state.

In this state, the runner 26 and the auxiliary gate 25 are filled with the resin from the gate 11c.

If the opening / closing member 21 is switched to the open position when the resin is substantially filled in the cavity 11a,
As shown by the arrow F in FIG. 7, the resin from the auxiliary gate 25 is injected to the contact portion between the resins, and the injected resin disperses the resins in the non-fusion state into the fusion state. It

Therefore, it is possible to prevent formation of a weld line in the resin layer 18 because there is no contact portion between the resins in the non-fusion state in the cavity 11a.

By the way, when resin containing glass fiber is injected into the cavity, the strength of the resin layer 18 is improved by entangling the glass fibers with each other. However, if the weld line is formed, the weld line is formed. Since the glass fiber does not get entangled in the line portion, the strength of the resin layer is not improved, and the strength in the weld line portion is significantly lower than the strength in the other resin layer portions, so stress concentrates on the weld line portion. Then, a crack will occur.

On the other hand, in the second embodiment, the resin is injected from the auxiliary gate 25 to the contact portion between the resins in the non-fused state, so that the resin containing glass fiber is used. If used, a new glass fiber entanglement can be formed in the same portion, and the strength of the resin layer 18 can be significantly improved.

In the second embodiment, the molding die 11 is
Although the auxiliary gate 25 is provided on the side opposite to the gate 11c in the circumferential direction, instead of the auxiliary gate 25, for example, the auxiliary gate 25 is provided on the opposite side in the circumferential direction at a position shifted by about 90 degrees. The gate 1 may be provided.
The auxiliary gate may be provided at a position separated from 1c in the circumferential direction.

Further, in each of the above-described embodiments, the vertical width of the resin escape chamber 19 and the openings 19a and 25a of the auxiliary gate 25 is set to be relatively smaller than that of the stator 15. The vertical width dimension of the portions 19a and 25a may be set to be substantially equal to that of the stator 15, and the shape of the resin inflow hole 21a of the opening / closing member 21 may be adapted to the opening dimension of the opening portions 19a and 25a. In this case, a large amount of the resin located at the contact portion between the resins flows into the resin escape chamber 19 and the auxiliary gate 25, so that the weld line can be surely formed over a wider area as compared with the above embodiments. It can prevent the occurrence.

Further, in each of the above-mentioned embodiments, the molding apparatus of the type in which the resin is injected into the cavity 11a by the plunger 14, that is, the so-called transfer molding apparatus is used, but an injection molding apparatus may be used. In this case, the cavity is used. 11a
A thermoplastic resin such as PBT or nylon is used as the resin injected into the inside.

[0053]

As is apparent from the above description, the present invention has the following effects.

According to the molding apparatus of the mold motor of the first aspect, the resin mold release chamber and the opening / closing member are provided in the molding die, and the opening / closing member is set to the closed position when the resin is being injected into the cavity, and the opening / closing member is provided inside the cavity. A weld line is generated in the resin layer because the resin escape chamber is not in communication with each other, and when the cavity is substantially filled with resin, the resin can be switched to the open position so that they are in communication with each other. In addition, it is possible to prevent the occurrence of coil layer shorts accompanying it, and thus it is possible to prevent the deterioration of the appearance of the mold stator, which lowers the commercial value and prevents the occurrence of cracks in the resin layer.

According to the molding apparatus of the mold motor of the second aspect, the molding die is provided with the auxiliary gate and the opening / closing member, and the opening / closing member is placed in the closed position when the resin is injected into the cavity to assist the inside of the cavity. In addition to the above effects, glass fibers, etc. can be used as the resin in addition to the above effects, because the gate is not in communication with each other, and when the cavity is almost filled with resin, it is in an open position so that they can communicate with each other. When a reinforcing agent-containing material is used, the strength of the resin layer can be significantly improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line EE of FIG.

FIG. 3 is an enlarged side view of the opening / closing member.

FIG. 4 is a vertical sectional front view of the mold stator.

FIG. 5 is a view corresponding to FIG. 4 showing a state where the rotor is mounted on the mold stator.

FIG. 6 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 7 is a cross-sectional view taken along the line of FIG.

FIG. 8 is a view corresponding to FIG. 1 showing a conventional example.

FIG. 9 is a top view of the mold stator.

FIG. 10 is a front view of a mold stator.

FIG. 11 is a sectional view taken along the line Har in FIG.

[Explanation of symbols]

11 is a mold, 11a is a cavity, 11c is a gate,
15 is a stator, 18 is a resin layer, 19 is a resin escape chamber, 21
Is an opening / closing member, and 25 is an auxiliary gate.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H02K 5/08 A 7254-5H // B29L 31:34 4F

Claims (2)

[Claims] 1. A mold in which a resin layer is formed to cover the stator by injecting resin through the gate in a state where the stator is housed in the cavity of the mold, wherein the gate is formed in the mold. A resin escape chamber, which is located on the opposite side in the circumferential direction and communicates with the inside of the cavity, is provided, and the resin escape chamber is provided between an open position for communicating the inside of the cavity and a closed position for disconnecting the cavity. A mold is characterized in that an openable and closable member that can be switched by is provided, and that the openable and closable member is in a closed position when resin is being injected into the cavity and is in an open position when resin is substantially filled in the cavity. Motor molding equipment. 2. A resin layer covering the stator is formed by injecting resin through the gate in a state where the stator is housed in the cavity of the molding die, and the molding die is connected to the gate. And an auxiliary gate which is located in the cavity and spaced apart from the gate in the circumferential direction and communicates with the gate. The auxiliary gate is in an open position and a non-communication state in which the auxiliary gate is in communication with the cavity. An opening / closing member that can be switched between the closing position and the closing position is provided, and the opening / closing member is set to the closing position when the resin is injected into the cavity and to the opening position when the resin is substantially filled in the cavity. A molding device for a mold motor.