JP2001018254A - Injection molding machine for putty-like thermosetting resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set up the capacity of a molding material supply part hopper to be enough as required and to improve the efficiency of work by separating a molding material injection part and a molding material supply part and connecting them by a flexible pipe. SOLUTION: An injection part 1 is composed of a cylinder 11 for driving a measuring/injection part, a cylinder 12 for driving a measuring/injection screw, a measuring/injection screw 13, a measuring/injection part cylinder 14, and a nozzle 15 and has a mold 2 and a mold clamping part 3. A molding material supply part 4 is composed of a hopper 41 and a molding material pressurizing cylinder 42. The injection part 1, the mold 2, the mold clamping part 3, and the molding material supply part 4 are made independent structures, and the injection part 1 and the molding material supply part 4 are connected by a flexible pipe 6. In the flexible pipe 6, a polymer pipe containing at least one of urethane rubber, nitrile rubber, or ethylene-propylene rubber, or an olefin resin, etc., is fitted to the inner wall.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a putty-like molding material injection / molding machine.

[0002]

2. Description of the Related Art A putty-like thermosetting molding material, that is, a BMC (Bulk Molding Comb) is generally used.
In the injection molding of a material called “pound”, the material supply section and the injection molding (material measurement and injection) section are structurally integrated. Therefore, each time the mold and the injection unit nozzle come into contact with or separate from each other to fill the mold with the material, the material supply unit moves integrally with the injection.

FIG. 2 is a schematic view of a conventional injection molding machine.

In FIG. 2, reference numeral 51 denotes a cylinder for driving a molding material supply unit and a metering / injection unit, 52 denotes a cylinder for driving a metering / injection screw, and 54 denotes a metering / injection unit having a metering / injection screw 53. 55 is a nozzle, 5
6 is a mold, 57 is a runner, 58 is a cavity, 59
Indicates a metal part. Numeral 60 designates a hopper 61 for storing the material in the molding material supply section and a pushing cylinder 62 for pressurizing the material in the hopper section. 63 indicates a molding material.

[0005] The molding process is as follows. First, the insert component is mounted on the mold 56, and the mold clamping cylinder 59 is mounted.
The mold is clamped. After the nozzle 55 and the mold 56 are pressed and held by the molding material supply unit 54 and the cylinder 51 for driving the metering / injection unit 54, a predetermined amount of the molding material 13
Is pressurized and filled into the mold 56 by the metering / injection screw drive cylinder 52. Next, after separating the nozzle 55 and the mold 56, a predetermined amount of the molding material is measured while rotating the measuring / injection screw 53 backward. During this time, the molding material 63 of the molding material supply unit 60 is pressed by the pushing cylinder 62. After a predetermined time, the mold is opened, the molded product in the mold 56 is taken out, and the molding process is completed.

[0006]

In the injection molding machine in the above molding step, the metering injection section 54 and the molding material supply section 60 have an integral structure. The process of contacting with and releasing from the mold 56 must be repeated simultaneously. That is, in order to frequently drive a heavy object such as the hopper 61 and the pushing cylinder 62 of the molding material supply unit 60, a high capacity molding material supply unit and a cylinder 51 for driving the metering / injection unit are required. In order to reduce the load on the cylinder 51, the capacity of the hopper 61 must be limited,
As a result, the material supply has been infrequent, resulting in inefficiencies in workability.

Further, due to the structure of the injection molding machine, the hopper 61
The material input port 64 must be provided at a high place where a ladder or the like is required for the work, and the material supply work requires a long time and special consideration from the viewpoint of safety.

Incidentally, the capacity of the hopper is 1-2.
In general, the size of the material is limited to such a degree that the material needs to be supplied once per hour, and the position of the material input port to the hopper is generally set at a height of 2 to 3 m above the floor. For this reason, the time required for one material supply operation is required to be 10 to 15 minutes, and air is entrapped in the material in the hopper every time the material is supplied, resulting in unstable measurement accuracy.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a putty-like thermosetting resin injection molding machine in which a molding material injection section and a molding material supply section are separated and both are connected by a flexible pipe. The capacity of the molding material supply unit hopper can be increased as required.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a molding material injection section,
This is a putty-shaped thermosetting resin injection molding machine in which the molding material supply unit is separated from the molding material supply unit and connected to each other by a flexible pipe, and the capacity of the molding material supply unit hopper can be increased as necessary. In addition, a molding material injection section with which the molding material contacts,
At least a part of the flexible pipe and the molding material supply section may have a temperature adjustable means. In addition, the molding material injection unit and the molding material supply unit
At least not move at the same time.

Further, the flexible pipe may be arranged in the order of a polymer pipe or a reinforced polymer pipe from the inner diameter side, and then a high heat conductive metal heat source or a heat medium (or heater). Also, the molding material injection unit measures and measures the material.
It has a metering / injection cylinder and a metering / injection screw (or plunger) having an injection function, and the cylinder and the screw (or plunger) may have a structure capable of coming into contact with and detaching from a mold. Further, the flexible pipe has a function of transferring the putty-like thermosetting resin injection molding material between the molding material supply section and the injection section, and contacts the fixed molding material supply section with the mold. It is desirable to have flexibility enough to withstand the repetitive movement of the ejection unit that operates for detachment.

The flexible pipe is hardly eroded by a putty-like thermosetting resin (eg, an unsaturated polyester resin), and is made of a rubber such as urethane, nitrile or ethylene propylene, or an olefin resin or a polyamide resin. A polymer pipe containing at least one kind of vinyl chloride resin, fluorine resin, polysulfone resin or the like may be provided on the inner wall. Also, the molding material supply section is composed of a hopper (material storage) and a pressure cylinder which can sufficiently withstand the internal pressure applied through the molding material, and the cross-sectional area of the hopper section is tapered toward the flexible pipe. It is better to be smaller as a whole.

[0013] The hopper is preferably characterized in that an air vent for venting air is provided at a molding material transfer outlet near the connection portion of the flexible pipe. Further, the pressurizing cylinder is preferably provided with rubber-like or plastic packing in the hopper inner diameter sliding portion. The molding process includes mold clamping, mold nozzle pressure contact, injection of molding material into the mold (screw (or plunger) advance), material measurement by screw (or plunger) retreat,
In molding consisting of mold nozzle detachment, molding material hardening, mold opening, and removal of molded product, the nozzle port is closed when the molding material is measured, and the molding material is sent from the molding material pumping section to the injection section via a flexible pipe. Good to be transported. Also,
It is preferable that at least one of the contact portions between the mold and the nozzle is provided with a member having better heat insulating properties than iron.

(Embodiment 1) This embodiment will be described with reference to FIG. Reference numeral 1 denotes an injection unit, and a cylinder 1 for driving a metering injection unit.
1, a measuring / injection screw (or plunger) driving cylinder 12, a measuring / injection screw (or plunger) 13, a measuring / injection section cylinder 14, and a nozzle 15. Reference numeral 2 denotes a mold, 3 denotes a mold clamping unit, 4 denotes a molding material supply unit, and a hopper 41 and a molding material pressurizing cylinder 4.
Consists of two. 5 indicates a flexible pipe, and 6 indicates a molding material.

As shown in FIG. 1, according to the present invention, the injection section 1, the mold 2, the mold clamping section 3, and the molding material supply section 4 are formed as independent structures, and both are formed by flexible pipes. It is an injection molding machine connected. Furthermore, the molding material 6 that has exited the material supply unit 4 passes through the flexible pipe 5 and enters the injection unit 1.
The injection unit 1 has a metering / injection unit cylinder 14, a metering / injection screw (or plunger) 13, and a nozzle 15. The metering / injection cylinder (or plunger) 14 is driven by a driving cylinder 12 to form a molding material. It rotates and / or retracts during metering and advances during injection to fill the mold 2 with the metered material. The nozzle 15 is brought into pressure contact with or separated from the mold 2 by the driving cylinder 11.

The mold 2 normally has a function of adjusting the temperature to a temperature sufficient for curing the thermosetting resin. The mold 2 is a split mold so that an insert product can be sometimes mounted and a molded product can be taken out. Opens and closes the mold.

The molding material supply section 4 has a hopper 41 capable of storing and pressurizing the molding material, and the putty-like molding material in the hopper 41 is supplied to an outlet toward the flexible pipe 5 by a pressure cylinder 42. Side is pressurized.

The flexible pipe 5 has a function of connecting the injection section 1 and the molding material supply section 4 so that the material can be transferred. The flexible pipe 5 has an outlet of the hopper 41 and an inlet of the cylinder 14 of the metering / injection section. Connected to. Here, the flexible pipe 5 is sufficient for the repetitive movement of the metering / injection unit cylinder 14 for performing pressure contact with and release from the mold 2 with respect to the fixed molding material supply unit 4 for each molding cycle. It is necessary to have flexibility that can withstand the pressure. Generally, it is necessary to introduce a corrugated pipe into at least a part of a pipe in which flexible rubber or plastics is reinforced with a wire net or a metal pipe.

In the injection molding machine of the present invention, the molding material supply section 4, the flexible pipe 5, and a part of the cylinder 14 of the measuring / injection section or the putty-like thermosetting resin molding material (hereinafter referred to as BMC) come into contact. All must be equipped with temperature adjustable means.

In particular, BMC is mainly composed of a thermosetting resin component which is liquid at room temperature, and is kneaded with a particulate or fibrous filler to form a putty. It has great properties. In the molding machine of the present invention within a certain specification range, the temperature difference due to the season, the temperature difference between morning and evening, the temperature difference due to the operation time, etc.
This is because the change in viscosity due to the temperature difference is sufficient to cause the molding machine to lose its function. That is, in the molding material supply unit 4, the pressure due to the predetermined amount of the hopper cross-sectional area, the hopper having the predetermined structure, the pipe length of the flexible pipe having the predetermined cross-sectional area, and the like cause obstacles due to the level of viscosity change that cannot be overcome. It is.

The temperature control is set to a temperature that is easy to control throughout the year and has a sufficient pot life of the BMC of 30 to 40.
C is desirable. Of course, as long as the pot life does not matter, the higher the temperature, the lower the viscosity of the BMC,
It goes without saying that workability is improved.

As a means for controlling the temperature, a method is generally used in which a portion surrounding the BMC is surrounded by a jacket in a bag shape and water or oil whose temperature is controlled is circulated in the jacket. It is also possible to use a method in combination with the above. That is, the hopper 41 and the metering / injection section cylinder which are made of a metal part and have a relatively large heat capacity use a jacket or adjust the temperature with an embedded heater or a belt-shaped heater. For example, a band heater is used.

In the temperature control of the flexible pipe, when the pipe is a corrugated pipe using a heat conductive metal,
Although the temperature distribution tends to be uniform, for example, in the case of a polymer reinforced pipe reinforced mainly with rubber or plastics and reinforced with a fiber or a wire mesh, it is easily affected by the state of heat distribution from the outer periphery, and the jacket method is not used. When a belt-shaped heater or the like is used as a heat source, a temperature difference is easily generated between a portion directly below the heater and a portion apart therefrom. In such a case, if a tape-shaped or net-shaped highly heat-conductive metal is arranged around the reinforced polymer pipe and, for example, a belt-shaped heater serving as a heat source is provided on the outer periphery thereof, the temperature uniformity over the entire pipe can be achieved.

The flexible pipe in the present invention must be made of a material which is not affected by the putty-like thermosetting resin molding material. Iron-based rather than copper-based corrugated metal pipes are preferred, and stainless steel is preferred.

For polymer pipes or reinforced polymer pipes, it is necessary to particularly consider styrene resistance and the like. For rubber, polyurethane, nitrile or ethylene propylene is used, and for plastics, olefin (polyethylene, polypropylene, etc.) is used. ), Polyamides, fluorines, vinyl chlorides, and polysulfones.

The material supply section 4 of the molding machine comprises a hopper 41 capable of sufficiently withstanding the internal pressure applied through the molding material and a pressure cylinder 42 for extruding the molding material. It is tapered toward the flexible pipe 5.

This kind of putty-like molding material, when pressurized, exhibits an intermediate pressure distribution which is neither pure liquid nor solid, and the pressure of the pressurizing cylinder 42 spreads into the flexible pipe 5. It is necessary to make the inner cross-sectional area of the hopper 41 closer to the inner cross-sectional area of the pipe with as loose a public distribution as possible. Generally, the taper angle is preferably 30 ° C. or more.

The hopper 41 is apt to enter air every time the material is supplied. When the material is put into the hopper 41 and the air is vented from the air vent when the pressure is increased by the pressurizing cylinder 42 to a predetermined pressure, the air in the hopper 41 escapes, and the material mixed with air into the pipe is removed. It is less likely to be fed, and the accuracy of material measurement in the metering / injection unit 14 is improved.

The sliding part of the inner wall of the hopper of the pressure cylinder 42 preferably has rubber or plastic packing. That is, when the hopper 42 is made of metal or hard plastics, the sliding portion of the pressurizing cylinder is made of a soft material, which is safer for maintenance. The material at this time needs to be a material which is not affected by the putty-like thermosetting resin, like the flexible pipe described above.

The molding process performed by the molding machine is as follows.

Mold clamping, nozzle pressure contact with the mold, injection / injection of molding material into the mold, material measurement, removal of the nozzle from the mold, curing of the molding material, opening of the mold, and removal of the molded product.

Here, the operation is performed by the mold clamping unit 3.
Is a cylinder 11 for driving the metering / injection unit, and a cylinder 1 for driving the metering / injection screw (or plunger).
2 is performed. Is measured by reversing a predetermined stroke in the case of a plunger, while the molding material 6 is moved from the hopper 41 by the pressing force from the molding material supply unit 4. It is transported via a flexible pipe. During this measurement, the nozzle 15 is closed. The nozzle opening may be closed by holding the molding material 6 in the mold 2 without detaching after filling the mold 2 or by providing a common valve in the nozzle separately.

The metering is accurately performed by closing the nozzle port, and the variation can be reduced.

When the nozzle opening is closed by pressurized contact with the mold 2, the mold usually hardens due to the hardening of the molding material.
Since the nozzle port is kept at a high temperature of about 0 ° C., the temperature of the nozzle port also becomes high, and the molding material in this portion is hardened, and the subsequent metering and injection cycle may be interrupted. For this reason, in the present invention, a heat insulating member is used for at least one of the contact portions of the nozzle 15 and the mold 2.

As the heat-insulating member, a flexible heat-resistant member that has a hardness that can withstand pressure contact at a high temperature and that can withstand an impact is required. Generally, a fluororesin containing an inorganic filler can be applied.

[0036]

An embodiment will be described below with reference to FIG.

[0037] In one injection unit, metering injecting portion drive cylinder 11 Fai45, stroke 100 mm, weighing injection plunger driving cylinder 14 is [phi] 60, applies a hydraulic cylinder stroke 110 mm, when the hydraulic pump 70 kg / cm ² , Maximum nozzle touch force about 110
It has a capacity of 0 kg and a maximum injection pressure of about 2000 kg.

Mold 2 is 100 mm × 100 mm × 1
Upper and lower molds each having 50 mm (height) and two φ20 mm × 20 mm cavities, each having a built-in heater of 500 W. During molding, the temperature of both the upper and lower molds was adjusted to 150 ° C.

The mold clamping portion 3 has a mold clamping force of 6 t and a stroke of 2
It is a single-acting type with a lower surface plate of 00 and has a die height of 270 mm.

The molding material supply section 4 comprises a hopper 41 and a pressure cylinder 42.
φ100mm × 300mm (depth) iron hopper 41
And φ80 for extruding molding material, stroke 300m
m, a cylinder 42. At this time, the cylinder pressure is a maximum total pressure of about 3500 kg, and can be about 45 kg / cm ² per sectional area of the hopper. The upper surface of the hopper 41 was provided with a taper of 45 ° from the inner diameter of the hopper to the diameter of the hose.

Further, an O-ring made of fluororesin (ethylene tetrafluoride) was used for the sliding portion of the inner wall of the hopper of the cylinder to prevent metal contact between the hopper and the cylinder.

The flexible pipe 5 is a high-pressure rubber hose reinforced with a composite of nitrile rubber, polyester cloth + nitrile rubber, stainless steel mesh + nitrile rubber, and has a pressure resistance of 200 kg / cm ² from the inner diameter. The hopper 41 of the molding material supply unit and the cylinder 14 of the metering / injection unit were connected to each other with an inner diameter of the high pressure rubber hose of 25.4 mm and a length of 1.5 m.

Here, a silicone rubber flexible heater and a heat insulating material are wrapped around the outer periphery of the molding material supply section hopper 41, the flexible pipe 5, the measuring / injection section cylinder 14 and the nozzle 15, and the molding material inside is 6 allowed each independently to 30-50 ° C.

The properties of the putty-like thermosetting resin molding material 6 used here are shown in Table 1.

[0045]

[Table 1]

[Note 1) Curast meter method] JSR
Using a mold curast meter, the distance between the upper and lower molds is 1.0 mm
About 10 g of the sample is placed in a mold set at 140 ° C., and the mold clamping and the start of the recorder are completed quickly (within 5 seconds). The oscillating angle at this time is 0.5 °. The gel time and the cure time are read from FIG. 3 obtained by a recorder.

[Note 2) BMC softness test method] ☆ Equipment / Jig 1.1 Constant temperature room or constant temperature bath Room or constant temperature room capable of holding at 30 ± 1 ° C. 1.2 Measuring device (shown in FIG. 4) Weight 71 [The total weight of the insertion jig is 15626.
g (jig = 126 g, weight = 1100 g)],
Insertion jig 72, insertion jig positioning jig 73 [height 6
5 mm], and has a hole for supporting the insertion jig shaft portion (φ8 portion) at the center thereof. However, the size must be large enough to pass smoothly. ], BMC sample container 75 [Set the insertion jig shaft to the center of the BMC. φ60 or more] ☆ Method 2.1 Preparation BMC sample and test equipment / jig for more than 3 hours at 30 ℃
Store in a room or constant temperature bath at ± 1 ℃. The measurement is performed at the above temperature. 2.2 Measurement Method BMC is filled into a sample container 75 to a position with a height of 95 mm so that no blank space or bubbles are formed. The insertion jig support 74 is set on the upper part of the sample container. Using the insertion jig positioning jig 73, the insertion jig 72 is set as shown in the figure. At this time, the tip tapered portion of the insertion jig is inserted into the BMC sample. Put the weight 71 as shown in the figure. A stopwatch is prepared, and the countdown is started at the same time as the insertion jig positioning jig 73 is removed. Time [S] until the lower surface of the insertion jig 72 contacts the upper surface of the insertion jig support 74
EC] is “soft”.

[Example of Formulation of Putty Thermosetting Resin]

[0049]

[Table 2]

[0050]

As described above, by connecting the molding material supply section and the metering / injection section with a flexible pipe as in the present invention, the capacity of the molding material supply section hopper can be increased as necessary. The capacity can be set, so that the number of times the material is put into the hopper can be set to 1 to 2 times / day, which greatly contributes to work efficiency.

Further, the reduction in the number of times the material is put into the hopper can minimize the variation in measurement due to air entrapment. There is also a great effect on the improvement of work efficiency by minimizing burrs and the like.

Also, unlike the conventional (relatively heavy), the material supply hopper and the metering / injection section do not have to be operated for each molding cycle, and the present invention requires only the metering / injection section to operate. The reduction in size and weight of the machine is great from the viewpoint of energy saving by reducing mechanical loss.
In addition, by shortening the molding cycle by reducing the weight of the working part, it is possible to contribute to improving molding productivity.

[Brief description of the drawings]

FIG. 1 is a diagram showing a putty-like thermosetting resin injection molding machine according to the present invention.

FIG. 2 is a view showing a putty-like thermosetting resin injection molding machine in a conventional example.

FIG. 3 is a diagram showing recording by a curastometer.

FIG. 4 is a diagram showing a test device for measuring softness.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injection part 2 Die 3 Mold clamping part 4 Molding material supply part 5 Flexible pipe 6 Molding material

Claims (12)

[Claims] 1. A putty-like thermosetting resin injection molding machine in which a molding material injection section and a molding material supply section are separated and both are connected by a flexible pipe. 2. The putty according to claim 1, wherein at least a part of the molding material injection section, the flexible pipe, and the molding material supply section with which the molding material comes into contact have means for adjusting the temperature. Thermosetting resin injection molding machine. 3. A molding material injection section and a molding material supply section,
The putty-like thermosetting resin injection molding machine according to claim 1, wherein the putty-like thermosetting resin injection molding machine does not move at least at the same time when the mold nozzle comes in contact with or separates from the mold nozzle. 4. The flexible pipe according to claim 2, wherein a polymer pipe or a reinforced polymer pipe is arranged from an inner diameter side, and then a high heat conductive metal heat source or a heat medium (or a heater) is arranged in this order. Putty-shaped thermosetting resin injection molding machine. 5. The molding material injection section has a measuring / injection cylinder and a measuring / injection screw (or plunger) having a function of measuring and injecting the material, and the cylinder and the screw (or plunger) are made of gold. 2. The putty-like thermosetting resin injection molding machine according to claim 1, having a structure capable of contacting with and releasing from a mold. 6. The flexible pipe has a function of transferring a putty-like thermosetting resin injection molding material between a molding material supply section and an injection section, and a mold and a mold are provided to the fixed molding material supply section. 2. A flexible member having sufficient flexibility to withstand repetitive movements of the injection portion operating for contact and detachment.
The putty-like thermosetting resin injection molding machine according to the above. 7. The flexible pipe is hardly eroded by a putty-like thermosetting resin (eg, an unsaturated polyester resin).
A polymer pipe containing at least one kind of rubber such as urethane, nitrile or ethylene propylene, or olefin resin, polyamide resin, vinyl chloride resin, fluorine, polysulfone resin, etc. The putty-like thermosetting resin injection molding machine according to claim 6, characterized in that: 8. The molding material supply section comprises a hopper (material storage) and a pressure cylinder capable of sufficiently withstanding the internal pressure applied through the molding material, and a cross-sectional area of the hopper section is tapered toward the flexible pipe. 2. The putty-like thermosetting resin injection molding machine according to claim 1, wherein the putty-like thermosetting resin injection molding machine gradually decreases in shape. 9. The putty-like thermosetting resin injection molding according to claim 8, wherein the hopper is provided with an air vent for venting air at a molding material transfer outlet in the vicinity of a flexible pipe connection portion. Machine. 10. The putty-like thermosetting resin injection molding machine according to claim 8, wherein the pressurizing cylinder is provided with rubber or plastic packing at a sliding portion of the hopper inside diameter. 11. The molding process includes mold clamping, mold nozzle press contact, injection of molding material into the mold (screw (or plunger) advance), material measurement by screw (or plunger) retreat, mold nozzle In the molding consisting of detachment, curing of the molding material, opening of the mold, and removal of the molded product, when the molding material is measured, the nozzle port is closed and the molding material is transferred from the molding material pumping section to the injection section via the flexible pipe. The putty-like thermosetting resin injection molding machine according to claim 1, wherein: 12. The putty-like thermosetting resin injection molding machine according to claim 11, wherein a member having better heat insulating property than iron is provided on at least one of the contact portions between the mold and the nozzle.