JP7375635B2 - Injection device and its lubrication and cooling method - Google Patents

Description

The present invention relates to an injection device and its lubrication and cooling method.

Taking a vertical injection device as an example, an injection device used in a die-casting machine etc. supplies molten metal into the injection sleeve with the injection device tilted, returns the injection device to an upright state, and then raises it. Combine it with the mold. Thereafter, the plunger tip inside the injection sleeve is raised to cast the molten metal inside the injection sleeve into the mold. In this manner, the plunger tip moves up and down within the injection sleeve. At this time, since the inner circumferential surface of the injection sleeve and the outer circumferential surface of the plunger tip slide, wear or galling may occur on the sliding surfaces. For this reason, lubricant is injected into the sliding surfaces between the injection sleeve and the plunger tip (for example, Patent Document 1).

On the other hand, during molding, it is necessary to apply lubricant from below to the mold gate (sprue) in order to promote release of the molded product. As a technique for applying a lubricant to a mold gate portion, for example, a method using a gate spray is known (for example, Patent Document 2).

JP2009-279645A Japanese Patent Application Publication No. 8-243709

However, since the above-mentioned conventional techniques use separate lubricant supply devices, there is a problem in that an injection device having both functions has a complicated configuration. Furthermore, in the conventional technology, it is difficult to use a coolant and a lubricant in combination, and by using both a lubricant and a coolant, there is a problem that an excessive amount of lubricant is produced, which adversely affects products and equipment.
Note that some mold release agents can suppress viscosity and can also be used as lubricants, and in this specification, these are also referred to as lubricants.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an injection device and a circulation method thereof that can simplify the configuration.
Another object of the present invention is to provide an injection device that can also be used in combination with a coolant, and a method for lubrication and cooling thereof.

An injection device according to an embodiment of the present invention includes a cylindrical injection sleeve, a cylindrical outer plunger that is coaxially arranged inside the injection sleeve and moves back and forth in the axial direction with respect to the injection sleeve, and The plunger includes an inner plunger that is coaxially arranged inside and moves back and forth in the axial direction with respect to the outer plunger. The inner plunger has a plurality of inner discharge ports provided on the outer periphery of the tip, and an inner fluid passage communicating with the inner discharge ports. The inner fluid passage is supplied with lubricant or coolant.
The outer plunger may include a plurality of outer discharge ports provided on the outer peripheral portion of the tip, and an outer fluid passage communicating with the outer discharge ports, and the outer fluid passage may contain the lubricant or the outer fluid passage. The coolant may be supplied.

In the injection device lubrication method according to the embodiment of the present invention, an outer plunger is coaxially arranged inside a cylindrical injection sleeve so as to be movable in the axial direction, and an inner plunger is arranged inside the outer plunger in the axial direction. A method for lubricating an injection device, which is arranged coaxially so as to be movable back and forth, and has a plurality of first discharge ports provided on the outer periphery of the tip of the outer plunger, and a plurality of second discharge ports provided on the outer periphery of the tip of the inner plunger. The outer plunger is moved in the axial direction within the injection sleeve, the lubricant is discharged from the first discharge port, and the lubricant is supplied to the inner circumferential surface of the injection sleeve, and the inner A plunger is made to protrude from the outer plunger, the inner plunger is moved in the axial direction inside the mold gate part, and the lubricant is discharged from the second discharge port, thereby supplying the lubricant to the gate part. do.

In a method for lubricating and cooling an injection device according to another embodiment of the present invention, an outer plunger is coaxially arranged inside a cylindrical injection sleeve so as to be movable back and forth in the axial direction, and an inner plunger is arranged inside the outer plunger. The injection device is coaxially arranged so as to be movable back and forth in the axial direction, and has a plurality of first discharge ports provided on the outer circumference of the tip of the outer plunger, and a plurality of second discharge ports provided on the outer circumference of the tip of the inner plunger. A method for lubricating and cooling an apparatus, wherein the outer plunger is moved in the axial direction within the injection sleeve with the inner plunger protruding relative to the outer plunger, and coolant is supplied from the first discharge port. is discharged to cool the injection sleeve, the inner plunger is moved in the axial direction together with the outer plunger, and the lubricant is discharged from the second discharge port to cool the inner circumferential surface of the injection sleeve and The lubricant is supplied to the gate portion of the mold.

According to the present invention, it is possible to provide an injection device with a simple configuration and a method for lubricating the same.
Further, according to the present invention, it is possible to provide an injection device and a lubrication and cooling method that can also be used in combination with a coolant.

FIG. 1 is a schematic cross-sectional view of an injection device according to an embodiment of the present invention. It is a figure showing the main part of the same injection device. FIG. 3 is a schematic cross-sectional view showing the operation of the injection device during injection molding. FIG. 3 is a schematic cross-sectional view showing a process of applying lubricant to the inner circumferential surface of the injection sleeve of the injection device. FIG. 3 is a schematic cross-sectional view showing a lubricant application process to a mold gate portion of the injection device. FIG. 3 is a schematic cross-sectional view showing a process of applying a lubricant to the inner circumferential surface of an injection sleeve and a mold gate portion and a process of cooling the injection sleeve of the same injection device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An injection device and a lubrication and cooling method thereof according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. However, the following embodiments do not limit the invention according to each claim, and not all combinations of features described in the embodiments are essential to the solution of the invention. .

FIG. 1 is a schematic cross-sectional view showing the configuration of an injection device according to a first embodiment of the present invention. As shown in FIG. 1, an example of a vertical injection device is shown as the injection device of this embodiment. The injection device includes a cylindrical frame 1, a cylindrical injection sleeve 2 attached to the tip of the frame 1, and a cylindrical outer plunger 3 coaxially arranged inside the frame 1 and the injection sleeve 2. , and an inner plunger 4 coaxially arranged inside the outer plunger 3.

In more detail, the outer plunger 3 is composed of, for example, an outer tip at the tip, an outer plunger rod that drives the outer tip, and an outer tip joint that connects these, but in the figure, these are shown as one structure. It is simplified as follows. In addition, the inner plunger 4 is also composed of, for example, an inner tip at the tip, an inner plunger rod that drives the inner tip, and an inner tip joint that connects these, but these are shown in the figure. It is simplified and shown as one configuration.

The outer plunger 3 and the inner plunger 4 are each driven individually by a fluid pressure drive unit 5 using hydraulic pressure or air pressure, and are configured to be able to move back and forth in the axial direction.

FIG. 2 shows details of the outer plunger 3 and the inner plunger 4, particularly the outer tip and inner tip portions. A cross-sectional view of the portion is shown to the right of the portion surrounded by the dotted line. 2(a) shows a state in which the tips of the outer plunger 3 and the inner plunger 4 are recessed from the tip of the injection sleeve 2, and FIG. The inner plunger 4 is shown rising to the tip position of the outer plunger 3 and protruding upward from the tip of the outer plunger 3.

As shown in FIG. 2, a plurality of first discharge ports (outer discharge ports) 3a are formed on the outer peripheral portion of the tip of the outer plunger 3, and are arranged at predetermined intervals in the circumferential direction and the axial direction. These first discharge ports 3a are bored in the radial direction, and their base ends are connected to a first fluid passage (outer fluid passage) 3b formed inside the outer plunger 3 and extending in the axial direction. Further, a plurality of second discharge ports (inner discharge ports) 4a are also formed on the outer peripheral portion of the tip of the inner plunger 4, which are arranged at predetermined intervals in the circumferential direction and the axial direction. These second discharge ports 4a are bored in the radial direction, and their base ends are connected to a second fluid passage (inner fluid passage) 4b formed inside the inner plunger 4 and extending in the axial direction. Lubricant or coolant is introduced into the first fluid passage 3b through the input port A at a predetermined timing. Lubricant or coolant is introduced into the second fluid passage 4b through the injection port B at a predetermined timing.

As shown in FIG. 1, this injection device is entirely driven up and down by a drive device (not shown), so that the molten metal inlet of the mold 10 and the tip of the injection sleeve 2 are connected. Further, when supplying hot water into the injection sleeve 2, this injection device is tilted to a position shown by a two-dot chain line by a drive device (not shown). Furthermore, the injection device introduces hydraulic oil or working air through the input ports C and D to drive the outer plunger 3 and the inner plunger 4 individually in the axial direction.

Next, the operation of the injection device configured as described above will be explained.
FIG. 3 is a diagram for explaining operations during injection molding. When the injection device is tilted, the inside of the injection sleeve 2 is filled with molten metal 6 by a ladle (not shown), and when the injection device returns to an upright position and rises, the tip of the injection sleeve 2 is exposed to the metal as shown in Fig. 3(a). It is now connected to the molten metal inlet of the mold 10. Here, the mold 10 is an example of a fixed mold 10a and a movable mold 10b that open and close in the horizontal direction, but it goes without saying that the present invention is also applicable to a mold that opens and closes in the vertical direction.

Next, as shown in FIG. 3(b), the outer plunger 3 and the inner plunger 4 are raised along the injection sleeve 2, and the molten metal 6 is cast into the cavity in the mold 10.

FIG. 3(c) shows a state in which casting has been completed. At this time, it is also possible to pressurize the molten metal with a pressure pin or the like (not shown) or to pressurize the molten metal by protruding the inner plunger 4 toward the gate.

FIG. 4 shows a method of lubricating the inside of the injection sleeve 2, which is performed before or after the series of injection molding steps described above. As shown in FIG. 4(a), the tip of the injection sleeve 2 is joined to the clamped mold 10 after the product is taken out or before injection molding is performed. In this state, the outer plunger 3 is moved up and down together with the inner plunger 4, as shown in FIGS. 4(a), (b), and (c). At this time, lubricant is introduced into the input port A. Thereby, the lubricant passes through the first fluid passage 3b, reaches the first discharge port 3a, and is discharged from the first discharge port 3a toward the inner circumferential surface of the injection sleeve 2. By reciprocating the outer plunger 3 a plurality of times, the lubrication process between the injection sleeve 2 and the outer plunger 3 is completed.
In addition, in the above-mentioned embodiment, an example was explained in which the outer plunger 3 is reciprocated multiple times, but it goes without saying that it is not necessary to reciprocate multiple times as long as the amount of lubricant ejected is sufficient. Even if the reciprocating operation is performed only once, it is sufficient that the lubricant can be sprayed for the necessary time to spray the necessary lubricant.

FIG. 5 shows a method of lubricating the gate portion (gate portion) of the mold 10, which is performed before or after a series of injection molding steps. As shown in FIG. 5(a), the tip of the injection sleeve 2 is joined to the clamped mold 10 after the product is taken out or before injection molding is performed. At this time, the tips of the outer plunger 3 and the inner plunger 4 are located at the tips of the injection sleeve 2. Then, as shown in FIGS. 5A, 5B, and 5C, only the inner plunger 4 is moved up and down while the outer plunger 3 remains stationary. At this time, lubricant is introduced into the input port B. Thereby, the lubricant passes through the second fluid passage 4b and reaches the second discharge port 4a, and is discharged from the second discharge port 4a toward the inner circumferential surface of the mold 10 near the gate portion. By reciprocating the inner plunger 4 a plurality of times, the lubrication process near the gate portion of the mold 10 is completed.
In the above-described embodiment, an example in which the inner plunger 4 is reciprocated a plurality of times has been explained, but as explained in the example of the outer plunger 3, if the amount of lubricant ejected is sufficient, the reciprocating operation is performed multiple times. Of course, it is not necessary to operate the lubricant, and even if the reciprocating operation is performed only once, it is sufficient that the lubricant can be sprayed for the necessary time to spray the necessary lubricant.

FIG. 6 shows a method of lubricating the inner circumferential surface of the injection sleeve 2 and the gate part (sprue part) of the mold 10, and a method of cooling the injection sleeve 2, which are performed before or after a series of injection molding steps. As shown in FIG. 6(a), the tip of the injection sleeve 2 is joined to the clamped mold 10 after the product is taken out or before injection molding is performed. Then, as shown in FIGS. 6(a), (b), and (c), with the inner plunger 4 protruding from the outer plunger 3 until the second discharge port 4a is exposed, the outer plunger 3 and The inner plunger 4 is moved up and down together. At this time, the coolant is introduced into the input port A, and the lubricant is introduced into the input port B.

Thereby, the coolant passes through the first fluid passage 3b, reaches the first discharge port 3a, and is discharged from the first discharge port 3a toward the inner circumferential surface of the injection sleeve 2. On the other hand, the lubricant passes through the second fluid passage 4b and reaches the second discharge port 4a, and from the second discharge port 4a, the lubricant is delivered to the inner circumferential surface of the injection sleeve 2 and the inner circumferential surface near the gate of the mold 10. is discharged towards. By reciprocating the outer plunger 3 and the inner plunger 4 a plurality of times, the cooling of the injection sleeve 2 and the lubrication process of the inner peripheral surface of the injection sleeve 2 and the vicinity of the gate portion of the mold 10 are completed.
In addition, in the above-mentioned embodiment, the example was explained in which the coolant was jetted from the outer plunger 3 for the purpose of cooling the injection sleeve 2. However, even if the structure is not such that the coolant is ejected from the outer plunger 3, if the structure is such that the coolant can be circulated within the outer plunger 3, it will not only be possible to cool the outer plunger 3 itself, but depending on the conditions. Furthermore, the effect that the inner plunger 4 can be cooled from the outer circumferential side can be expected.

[Effects of embodiment]
According to the above embodiment, the injection device alone can supply lubricant to both the injection sleeve 2 and the gate portion of the mold 10, so there is no need for special devices such as a gate spray, and the device configuration This has the effect of simplifying.
In addition, since the lubrication and cooling processes can be performed while the injection sleeve 2 is connected to the clamped mold 10, the lubrication and cooling processes with the injection device tilted are not necessary. . Therefore, the cycle time of injection molding can be shortened.
Furthermore, by supplying lubricant and coolant separately, the amount of lubricant supplied can be reduced. Using air as the coolant can reduce costs and improve safety.

In addition, when supplying the coolant, the temperature of the injection sleeve 2 may be measured with a temperature sensor 8 such as a thermocouple shown in FIG. 6, and the supply amount of the coolant may be controlled according to the measurement result.
According to this, it is possible to maintain the injection sleeve 2 at an appropriate temperature while keeping the amount of lubricant at an appropriate level.

In each of the above lubrication methods and cooling methods, the lubricant or coolant is injected with the injection sleeve 2 connected to the molten metal inlet of the mold 10, but regarding the lubrication or cooling of the injection sleeve 2. This can also be done when the injection device is tilted. In this case, for example, as shown by the two-dot chain line in FIG. The lubricant or coolant may be recovered from.

Further, in the above embodiment, the explanation has been given by taking a vertical injection device as an example, but the present invention is also applicable to a die casting device equipped with a horizontal injection device.

Although the embodiment of the present invention has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. This embodiment and its modifications are included within the scope and gist of the invention, as well as within the scope of the invention described in the claims and its equivalents.

1 Frame 2 Injection sleeve 3 Outer plunger 4 Inner plunger 5 Fluid pressure drive unit 6 Molten metal 10 Mold

Claims (3)

a cylindrical injection sleeve;
a cylindrical outer plunger that is coaxially arranged inside the injection sleeve and moves back and forth in the axial direction with respect to the injection sleeve;
an inner plunger that is coaxially arranged inside the outer plunger and moves back and forth in the axial direction with respect to the outer plunger,
The inner plunger has a plurality of inner discharge ports provided on the outer circumference of the tip, and an inner fluid passage communicating with the inner discharge ports,
A lubricant or a coolant is supplied to the inner fluid passage ,
The outer plunger has a plurality of outer discharge ports provided on the outer circumference of the tip, and an outer fluid passage communicating with the outer discharge ports,
The lubricant or the coolant is supplied to the outer fluid passage.
An injection device characterized by: An outer plunger is coaxially arranged inside the cylindrical injection sleeve so as to be movable in the axial direction, and an inner plunger is coaxially arranged inside the outer plunger so as to be movable in the axial direction, and an outer peripheral portion of the tip of the outer plunger. A method for lubricating an injection device in which a plurality of first discharge ports are provided in the inner plunger, and a plurality of second discharge ports are provided in the outer peripheral portion of the tip of the inner plunger, the method comprising:
moving the outer plunger in the axial direction within the injection sleeve, discharging the lubricant from the first discharge port, and supplying the lubricant to the inner circumferential surface of the injection sleeve;
The inner plunger is made to protrude from the outer plunger, the inner plunger is moved in the axial direction inside the mold gate part, and the lubricant is discharged from the second discharge port to the mold gate part. A method for lubricating an injection device, characterized by supplying a lubricant. An outer plunger is coaxially arranged inside the cylindrical injection sleeve so as to be movable in the axial direction, and an inner plunger is coaxially arranged inside the outer plunger so as to be movable in the axial direction, and an outer peripheral portion of the tip of the outer plunger. A method for lubricating and cooling an injection device in which a plurality of first discharge ports are provided in the inner plunger, and a plurality of second discharge ports are provided in the outer periphery of the tip of the inner plunger, the method comprising:
With the inner plunger protruding relative to the outer plunger, the outer plunger is moved in the axial direction within the injection sleeve, and coolant is discharged from the first discharge port to cool the injection sleeve. At the same time, the inner plunger is moved in the axial direction together with the outer plunger, and the lubricant is discharged from the second discharge port, thereby discharging the lubricant onto the inner circumferential surface of the injection sleeve and the gate portion of the mold. A method for lubricating and cooling an injection device, characterized in that:

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