JPH0358575B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an armature for a flat type motor in which a mold layer is formed on an armature coil using polyphenylene sulfide resin having high strength and ultra-high fluidity. This invention relates to a hot runner injection molding apparatus for manufacturing.

[Conventional technology]

Conventionally, this type of flat motor armature has been disclosed, for example, in Japanese Patent Laid-Open No. 57-52352.
It is known that amateur coils are molded in resin.

This molding equipment consists of a so-called runner, a resin filled in the resin channel connecting the nozzle of the molding machine and the cavity of the mold, and an armature sealed with the resin filled in the cavity, which are cooled and solidified. There is a cold runner system that discharges the armature out of the mold when the mold is opened.

However, this system has problems such as the need for post-processing steps such as resin loss and treatment of the spool and runner parts, and cutting and finishing of the gate.

Therefore, conventionally, a runner-less system, a so-called hot runner system, has been proposed in which molten resin is directly injected into a cavity from a gate.

According to this system, there is no deformation or warping of the coil due to injection pressure, and surface runout, umbrella distortion, etc. during armature rotation are extremely small compared to the cold runner system, which is superior. There is no resin loss in the spool and runner parts. Since it can be cut from the gate and automatically taken out, there is no need to cut or finish the gate, which can be expected to save labor.

An example of this hot runner system is as follows.

(1) Valve gate system (Saito Koki Co., Ltd.) that installs a mechanical valve in the gate part to keep the resin near the gate in a molten state, and closes the valve when the mold is opened to prevent the resin from stringing or dripping. )Inco Inc.).

(2) A pointed heating element in the resin flow path near the gate hole is placed so as to face the gate hole, and when the mold is opened, the resin in the gate hole is cooled and solidified, and the heating element is placed in the resin flow path near the gate hole to cool and solidify the resin immediately before injection for the next cycle. Electric heating is applied to remelt the solidified resin in the gate hole to enable injection. The so-called intermittent heating method [BASF system (direct heating hot chip "Thermoplay")].

(3) All-internal heating method [Japan DME system (hot chip heating method)] with a built-in heater tube and probe (hot chip) with a thermocouple cartridge heater sealed inside the runner and gate hole of the distributor block.

[Problem that the invention seeks to solve]

However, according to experiments conducted by the present inventor, it has been confirmed that each of the above methods has the following problems and is unsuitable for manufacturing armatures for flat type motors.

In method (1), the valve part is likely to wear out and break down due to the large number of repeated openings and closings. The device becomes larger due to the use of a valve with a complex structure.

In method (2), it takes time to remelt the solidified resin. Injection pressure is reduced. The tip of the heating element may be damaged or worn out due to the resin mixed with glass fibers, causing inconvenience. There is a problem in that the tip of the heating element becomes so hot that the resin around the base burns or decomposes.

In this method, the shape of the probe becomes large. Under conditions where the resin temperature is 350℃ and the mold temperature is 150℃, there is a close contact structure between the mold and the block with no insulation zone such as an air gap, so the cooling effect of the mold decreases and resin leaks etc. .

The present invention was made in order to solve such conventional problems, and its purpose is to use a spear that has a built-in body heater and a tip heater built in at the tip, thereby making it possible to use a spear made of polyphenylene sulfide resin. An object of the present invention is to provide a hot runner type injection molding device for an armature for a flat type motor, which can uniformly and quickly perform resin molding of amateur coils.

[Means for solving problems]

The hot runner type injection molding device for an armature for a flat type motor according to the present invention has a storage section in which an armature coil formed by superimposing a large number of single coils into an annular shape using a molding jig and connecting it to a commutator is installed. It consists of a mold provided and three spears that inject polyphenylene sulfide resin having high strength and ultra-high fluidity into the storage part of this mold,
Each spear has a built-in body heater and a tip heater, and is held at equal intervals in a manifold in which a cartridge heater is provided, and the temperature of each spear can be individually controlled by a temperature controller.

[Effect]

In the present invention, by using a spear with a built-in body heater and a tip heater built into the tip, the resin flow path is constantly filled with molten resin, and the resin at the tip of the spear is melted in a short time during injection. Then, the polyphenylene sulfide resin, which has high strength and ultra-high fluidity, is injected directly into the mold housing part under ultra-low pressure in a timely manner.
The resin mold layer formed on the armature coil becomes uniform and the molding speed becomes faster.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a partially cutaway front view of the device according to the present invention, and FIG. 2 is a cross-sectional view showing the main parts thereof.
FIG. 3 is a plan view of a flat type motor armature formed according to this embodiment, and FIG. 4 is a sectional view thereof.

In the figure, 1 is three spears, which are fixed to a manifold 5. Casinge 2 for each spear 1
A runner bush 23 is provided at the runner bush 23. A tip heater 3 is provided at the tip of each spear 1. Spear 1 protruding from manifold 5
A lead wire 4 is taken out from the other end. or,
The manifold 5 is formed with a cartridge heater insertion hole 6 into which a cartridge heater 7 is inserted, and a thermocouple insertion hole 8 into which a thermocouple 9 is inserted.

As shown in FIG. 3, the three spears 1 are attached to the boss portion 31 of a resin-molded armature coil 30 as a product so that gates 32 are formed at equal intervals. In addition, 33 is a sleeve.

In addition, the spear 1 is equipped with a chip heater 3 for melting the solidified resin in the land portion 1A, and a body heater (not shown) for maintaining the resin around the spear 1 at an appropriate temperature (310 to 350 degrees Celsius). They are installed in the structure, and each is controlled by a separate Spear System Controller.

The runner portion 1B of the spear 1 is formed in a path connecting the spear 1 and its casing 2, inside the manifold 5, the spool bush 21, and the locate ring 22.

A stationary mold 10 is attached to the chip heater 3 side. The stationary mold 10 has a concave portion 11 connected to the chip heater 3 and forming a housing portion 12 for mounting an armature coil formed by superimposing a large number of single coils into an annular shape using a molding jig and connecting them to a commutator. It is provided as follows. Also, fixed side mold 1
0, a cartridge heater mounting hole 13 for mounting a cartridge heater 14 and a cooling liquid hole 15 for passing a cooling liquid are formed separately.

A movable mold 16 is assembled to the fixed mold 10. Similar to the stationary mold 10, the movable mold 16 has a storage part 12 in which an amateur coil is attached, which is formed by superimposing a large number of single coils into an annular shape using a molding jig and connecting them to a commutator. A recess 17 is formed. In addition, the movable side mold 16, like the fixed side mold 10, has a cartridge heater mounting hole 18 for mounting the cartridge heater 19 and a coolant hole 20 for passing the coolant. It is formed separately.

The stationary mold 10 and the movable mold 16 are designed to be able to be opened by a known method.

Next, the operation of this embodiment configured as described above will be explained.

In this apparatus, as shown in FIG. 5, the resin guided by the runner part 1B, which is always in a molten state, is cooled and solidified together with the resin in the cavity in the gate land part 1A. After taking out the product and before starting the next injection, the chip heater 3 is energized to generate heat and the land portion 1 is heated.
The solidified resin in A can be melted and injected.
This repeating process is synchronized with the cycle of the molding machine, allowing for fully automatic molding.

Therefore, first, a large number of single coils are superimposed and annularly formed using a forming jig into the housing part 12 formed by the stationary side mold 10 and the movable side mold 16 according to a conventional method, and a commutator is used. Attach the amateur coil that is connected.

On the other hand, the resin in the manifold 5 is divided into two systems and kept warm by a temperature-controlled cartridge heater 7. (310-350℃). The resin that has passed through the manifold 5 passes around the spear 1 and its casing 2 and temporarily stagnates. The resin in this portion is housed in the spear 1, is kept warm by a temperature-controlled heater, and is directed toward the gate land portion 1A to form an insulating layer. The gate land portion 1A has a mold 10,
16 to solidify by cooling except during injection,
Immediately before injection, the chip heater 3 is energized to generate heat and melt, and the resin is injected into the storage section 12 to form a resin layer on the armature. The heat generation timing and heat generation time at this time are automatically repeated for each shot, and the temperature control output is adjusted individually for each gate.

The fixed side and movable side molds 10 and 16 are 130 to 150
℃, but in order to rapidly raise the temperature to a predetermined temperature, the cartridge heaters 14 and 19 inserted into the cartridge heater holes 13 and 18 are energized.
Heat to raise temperature.

Furthermore, when continuous molding is performed, resin heated to 310 to 350° C. is injected, so the temperatures of the fixed and movable molds 10 and 16 gradually rise. If this is cooled in a conventional manner, it will take a long time and the molding cycle will be lengthened.

Therefore, in order to cool the molds 10 and 16, a cooling liquid (oil at 100 to 150°C) is circulated through the cooling liquid holes 15 and 20 to control the mold temperature to 130 to 150°C.

In addition, by automatically controlling the spear temperature controller (not shown), the mold temperature is always kept at 130~130°C.
It is possible to control the temperature at a constant temperature within the range of 150℃, and it is possible to manufacture armature molded products with constant quality. In addition, since the spear 1 is placed at each gate position via the manifold 5, the spear 1 and the manifold 5 to be assembled into the mold 10, a controller and a relay box (not shown) for setting and controlling the output and temperature are provided. be able to.

When carrying out the present invention, if a three-point gate system using three spears 1 is used as in the above embodiment, the resin mold layer of the armature for a flat type motor can be uniformly molded.

This will be explained based on the inventor's experiments.

In the case of a three-point gate, there are three welds (joints) 41 between each gate 40, as shown by the dotted line in FIG. It is completely filled with an even flow distance as shown.

As is clear from this experiment, the gate balance is excellent. Since the weld 41 is completely sealed, there are no defects. There are no cracks, warpage, or deformation in the molded product.

If a single point gate is used, as shown in FIG. 8, the flow distance from the gate 40 to the weld 41 becomes longer, resulting in a difference in material flow time. Therefore, the weld 41 is not completely sealed, causing cracks and weakening the strength. Since it shows a flow trajectory like an arrow, the orientation of the glass fibers makes it difficult to fill the left and right sides of the weld, making it difficult to form a perfect circle as shown in FIG. Moreover, the weld shaft 42 is deformed as shown in FIG.

Furthermore, if a two-point gate is used, as shown in FIG. 11, the flow distance becomes longer, although not as much as a one-point gate, so that the weld 41 is not completely sealed, causing cracks and a decrease in strength. Since it shows a flow trajectory as shown by an arrow, it deforms on the left and right sides of the weld 41 due to the orientation of the glass fibers in the same way as a one-point gate. Also, it is difficult to make a perfect circle.

Therefore, in addition to eliminating deformation and warping of the armature,
In order to enable molding without surface runout, umbrella distortion, etc. when the armature rotates, a three-point gate is required.

〔Effect of the invention〕

As described above, according to the present invention, there is provided a mold provided with a storage section for mounting an amateur coil formed by superimposing a large number of single coils into an annular shape using a forming jig and connected to a commutator, and this mold. It consists of three spears that inject polyphenylene sulfide resin with high strength and ultra-high fluidity into the storage compartment of The runners (resin flow path) are held at equal intervals in a manifold equipped with a runner, and the temperature of each can be controlled individually by a temperature controller. The resin in the runner part is constantly heated to keep it in a molten state, while the tip heater in the land part at the tip of the spear is turned on and off according to the injection cycle, solidifying the resin and sealing the gate after injection. , the resin is melted just before the next injection, and
The temperature of the spear's body heater and chip heater is individually controlled, and the resin injected from the three gates is all under the same conditions, so even though it has a simple structure, there is no resin leakage or resin burning, and the storage area It is possible to supply resin evenly to
It has become possible to quickly mold high-quality products. Furthermore, compared to the cold runner type, there is no deformation or warping of the coil due to injection pressure, and surface runout, umbrella distortion, etc. during armature rotation are extremely small compared to the cold runner type. There is no resin loss at all in the spill and runner parts. Since it can be cut from the gate and automatically taken out, there is no need to cut or finish the gate, resulting in labor savings. Therefore, resource and labor savings are achieved as a whole, so there are advantages such as being able to provide a low-cost armature molded product.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view of the device according to the present invention, and FIG. 2 is a cross-sectional view showing the main parts thereof.
FIG. 3 is a plan view of a flat type motor armature molded according to this embodiment, FIG. 4 is a cross-sectional view thereof, FIG. 5 is a diagram showing the temperature characteristics of the spear tip heater used in the present invention, and FIG. 6 11 to 11 are explanatory diagrams showing a comparison between the three-point gate and other gates in the present invention. DESCRIPTION OF SYMBOLS 1... Spear, 1A... Land part, 1B... Runner part, 2... Spear casing, 3... Chip heater, 5... Manifold, 10... Fixed side mold, 12... Storage part, 16... Movable side mold, 3
0... Amachi Your Coil, 32... Gate.

Claims (1)

[Claims] 1. A mold with a storage section for installing an amateur coil formed by superimposing a large number of single coils into an annular shape using a forming jig and connecting it to a commutator, and a mold with a storage section of this mold that has a high strength and It is composed of three spears that inject polyphenylene sulfide resin with high fluidity, and each spear has a built-in body heater and a chip heater at the tip, and is spaced equidistantly from the manifold where the cartridge heater is installed. 1. A hot runner type injection molding device for a flat type motor armature, characterized in that the armatures are held at a temperature controller and the temperature of each armature can be individually controlled by a temperature controller.