JPH0794060B2 - Feeder rod device for injection molding equipment - Google Patents

Description

The present invention relates to an injection molding apparatus such as a die casting machine or a plastic injection molding machine for molding a molded product by injecting a molten material into a cavity of a mold. The present invention relates to a feeder rod device that inserts a feeder rod into a melt that is injected and filled in a mold cavity to perform feeder.

[Conventional technology]

For example, Japanese Patent Laid-Open No. 63-140747 proposed as an injection molding apparatus of this type discloses a mold opening / closing unit of a rotary die casting machine for casting a disk wheel for automobiles made of aluminum or the like. It is configured like. That is, above the lower mold fixed on the mounting plate, the upper mold is provided by being supported by a top plate which is moved up and down by a mold opening / closing cylinder standing on the mounting plate. Between the molds, there are provided, for example, four cores that are driven by a cylinder and move forward and backward in the radial direction. A cavity is formed between the upper and lower molds that have been clamped and the closed core, and a fixing sleeve having an inner hole communicating with the cavity is formed in the center of the lower mold. It is fitted through the hole of the mounting plate.

With this structure, the mold opening / closing unit is supplied onto the rotary table, the rotary table is rotated, and the mold is stopped at the injection station to clamp the mold, and then the injection sleeve is joined to the fixed sleeve for injection. When the molten metal pressed by the injection cylinder on the station side is injected into the cavity through both the injection and fixed sleeves, it solidifies and a product is obtained. After that, the mold is opened and the product is taken out.

In such a die casting machine, since the molten metal may not spread to every corner of the cavity and the quality of the product is deteriorated, this mold opening / closing unit is provided with a feeder rod that advances and retreats into the cavity by a driving device. Immediately before or after the injection of the molten metal into the cavity is completed or immediately after that, the molten metal is pushed by advancing this feeder rod into the cavity, so that the molten metal spreads in every corner of the cavity and a dense product can be obtained. To be Since the feeder rod is deteriorated or damaged by being inserted into the molten metal having a high temperature, the feeder rod is provided with a water cooling type cooling device.

[Problems to be Solved by the Invention]

However, the feeder rod device provided in such a conventional injection molding apparatus is such that the feeder cylinder is fixed on the top plate and the feeder rod is concentric with the working end of the piston rod through a coupling. A cooling pipe that is fixed and hung down and penetrates the axial center of the feeder rod is provided, and the cooling water supply port and discharge port of this cooling pipe are provided at the root of the feeder rod or the coupling. Since the feeder cylinder and feeder rod are connected in series, the height of the feeder rod apparatus increases, occupying more space in the apparatus, and cooling up and down parts. Since water must be piped, it is necessary to connect it with a hose, and not only can it not be made compact, but there is also the problem that maintenance and inspection work is difficult due to its structure.

The present invention has been made in view of the above points, and a feeder rod device of a compact injection molding machine having a configuration that enables a feeder rod and a feeder cylinder to be provided in a hole of a mold. It is intended to be provided.

[Means for Solving the Problems]

In order to achieve such an object, according to the present invention, a cylinder part fixed to a mold and a hollow part which is slidably fitted in an inner hole of the cylinder part and has a tip part communicating with a cylinder part front chamber -Shaped piston rod whose rotation is restricted by a guide rod, a rear piston rod that extends rearward from this piston, and a front piston rod that extends forward from the piston and is inserted into a through hole of a mold In addition to connecting the feeder rod, which has a cylinder formed and the tip of which is freely inserted into and removed from the cavity of the mold, to the front piston rod,
A cooling pipe that extends from the rear end of the rear piston rod to the front end of the feeder rod and penetrates through its center is provided, and the inside and outside of this cooling pipe are connected to the cooling water supply port and cooling water supply port, respectively. A cooling water passage is provided.

[Work]

If the melt is filled in the mold cavity and oil is supplied to the rear of the piston of the feeder cylinder immediately before or after it begins to solidify, the feeder rod, which is integral with the front piston rod of the feeder cylinder, moves forward and its tip ends. Enters the melt in the cavity and is raised so that the melt spreads throughout the cavity.

During the riser, the cooling water supplied from the water supply port into the cooling pipe folds back at the tip of the riser rod and is discharged from the drainage port through the cooling water passage, so the piston rod and the riser rod are cooled during this time. It

〔Example〕

1 and 2 show an example in which the feeder rod device of an injection molding machine according to the present invention is applied to a mold opening / closing unit of a rotary die casting machine, and FIG. 1 is a longitudinal sectional view of the feeder rod device. The figure is a vertical sectional view of a mold opening / closing unit in which this is performed. In the figure, the rotary die casting machine includes a rotary table (not shown) and three sets of mold opening / closing units 1 that are supplied and mounted at positions that divide the outer peripheral portion thereof into three equal parts in the circumferential direction. Three work stations are provided at the stop position of the mold opening / closing unit, which rotates by 120 ° and stops by rotating by 120 °. Each mold opening / closing unit 1 is equipped with a mold, which will be described later. At each of the three work stations, mold closing / injection, mold opening / product taking-out, and mold opening / closing for each mold opening / closing unit are performed. Cleaning and spraying with a release agent are performed, and one cycle is completed by rotating the rotary table once.
The drawings show the mold opening and closing units stopped at the mold clamping and injection stations, respectively, and a mold clamping device and an injection device (not shown) are arranged above and below in FIG.

In the figure, a mold opening / closing unit 1 is equipped with a mounting plate 2 fixed on a rotary table (not shown), and a piston which is lifted and lowered by the hydraulic pressure of a pair of mold opening / closing cylinders 3 standing upright on both left and right sides of the mounting plate 2. A horizontal plate-shaped top plate 5 is fixedly supported on the working end of the rod 4. Then, as the piston rod 4 moves back and forth, the top plate 5 and an upper mold 6 to be described later are moved up and down to perform mold opening and mold matching. The mounting plate 2 includes a substrate 7a, side plates 7b,
A lower mold 7 which is disassembled and joined to the spacer 7c and the injection plate 7d is fixed, and the central part of the lower mold 7 is
A fixed sleeve 8 formed in a cylindrical shape is fitted.

On the other hand, the drum-shaped upper mold 6 fixed to the lower surface of the top plate 5 has a concave hole 6a having a substantially square cross section which opens upward,
A projecting portion 6b projecting downward from the central portion of the lower end surface is provided, and a plurality of cores 9 divided in the circumferential direction are provided around the projecting portion 6b. It is supported and provided on a piston rod 12 of a core cylinder 11 supported via A cavity 13 is formed by the lower mold 7, the upper mold 6 that is clamped against the lower mold 7, and the closed core 9. On the other hand, an injection sleeve 14 on the injection cylinder side (not shown) is detachably joined to the fixed sleeve 8. After the molten metal 15 is supplied to the injection sleeve 14, the plunger 16 is moved forward so that the molten metal 15 is melted. It is configured to be injected into the cavity 13 via a passage 17.

Next, the feeder rod device according to the present invention housed in the square recess 6a of the upper die 6 will be described. A feeder rod device generally designated by the reference numeral 20 is a main body 21a and a main body 21a which are formed into a bottomed rectangular tube shape and are fitted and fixed in the recessed holes 6a.
Cylinder part 21 consisting of lid 21b closing the lower end opening of
A piston 22 slidably fitted in the inner hole 21c of the cylinder portion 21, a rear piston rod 23 having a flange portion bolted to the piston 22 and extending rearward, and a piston 22
It is equipped with a double-sided piston type feeder cylinder 25 formed by a front piston rod 24 extending forward from the front piston rod 24, and the front piston rod 24 is slidably supported by a bearing 26 bolted to the lid 21b. Has been done. Of the members constituting the feeder cylinder 25, the bottom plate 21c of the cylinder portion 21 has an oil inlet / outlet port 21d.
And an annular groove 21e communicating with this is provided. Further, a plurality of rod holes 22a provided at positions equally divided in the circumferential direction of the piston 22 are formed in a hollow tubular shape to form a cylinder portion 2
A guide rod 27 fixed to the bottom plate 21c of No. 1 is slidably fitted, and the tip end of this guide rod 27 is engaged with a recessed hole 21f provided in a lid 21b of the cylinder portion 21. The inside of the tip of the hollow tubular guide rod 27 communicates with the front chamber of the cylinder 21, and the upper end of the guide lot 27 has an oil inlet / outlet port 21g that communicates with the inner hole of the guide rod 27. The piston 22 is provided and is configured to supply oil to the lower side of the piston 22.

In addition, the inside of the tip of the tubular guide rod 27 is
When communicating with the anterior chamber of, as shown in Fig. 1,
The tip end surface of the guide rod 27 may be placed slightly apart from the bottom plane of the recess 21f, or the guide rod 27
The front end surface of the guide rod 27 may be brought into contact with the bottom flat surface of the concave hole 21f, and a lateral groove or a lateral hole may be provided in the peripheral wall surface of the distal end portion of the guide rod 27.

In this case, the guide rod 27 has a role of a guide for moving the piston 22, a role of preventing rotation of the cylinder 22, and a role of moving hydraulic oil into and out of the front chamber of the cylinder portion 21.

Furthermore, the male screw portion 28a of the joint 28 is screwed into the female screw portion formed at the lower end portion of the front piston rod 24, and the other male screw portion 28b of the joint 28 is the same as the female screw portion of the feeder rod 29. It is screwed. And piston 22
When the piston 22 of the feeder cylinder 25 moves forward and backward by refueling above and below, the feeder rod 29 is inserted into and removed from the cavity 13. The tip end surface of the feeder rod 29 may be arcuate as shown in FIG. 1 or may be an inverted truncated cylinder. Further, by rotating the joint 28, the entire lengths of the rear piston rod 24 and the feeder rod 29 connected to the joint 28 are adjusted by a screw action.

The recess 21 is formed in the hole 21h formed in the bottom plate 21c of the cylinder portion 21.
A block 30 having a substantially square shape in plan view having a and 30b is provided with a protrusion 3
0c is engaged, and the bottom plate 21c and the block 30 are fixed by a plurality of bolts 30g. The upper end surface of the block 30 is flush with the upper end surface of the upper mold 6, and is provided in contact with the lower surface of the top plate 5. As a result, even if the upper die 6 has the recessed hole 6a for installing the feeder rod device 20, the strength of this portion is sufficiently maintained. The block 30 is provided with a water supply port 30d and a drainage port 30e, which are connected to a cooling water source (not shown) by piping, and the rear piston rod 23 is a space part provided in the block 30.
The drainage port 30e is installed in the space 30
It is connected to f. 31 is a cooling pipe communicated with the water supply port 30d, and this cooling pipe 31 is a block at the upper end of the device.
30 through rear piston rod 23, piston 22, front piston rod 24, joint 28, and feeder rod 2 at the lower end of the device.
It extends through the axial center of the members up to 9 and the lower end thereof is opened in the inner hole 29a of the feeder rod 29. A cooling water passage 32 is provided between the piston 22, the front piston rod 24, and the cooling pipe 31 in such a manner that upper and lower annular grooves 33, 34 are communicated with each other, and the joint 28 and the cooling pipe 31 are connected to each other. A cooling water passage 35 is provided in the upper and lower annular grooves 34, 36 to communicate with each other. Further, the space 30f and the annular groove 3
A cooling water passage 37 communicates with the parts 3 and 3. By doing so, the cooling water supplied from the water supply port 30d passes through the inside of the cooling pipe 31, reaches the inner hole 29a of the feeder rod 29, makes a U-turn, and drains through the cooling water passages 35, 32, 37. Although it is discharged from the mouth 30e, the feeder rod 29, the front piston rod 24 and the like are cooled by cooling water during this period. The cooling pipe 31 is divided in the axial direction by the dividing surface 31a. Further, the cooling pipe 31 may be a single pipe, or a double pipe may be a slide type and the length thereof may be adjusted.

38 is a displacement sensor fixed on the bottom plate 21c,
It is connected to a control device by a lead wire 39, and a detection rod 40 which is also a magnetostrictive wire parallel to the guide rod 27 is fixed to the displacement sensor 38 so that the detection rod 40 engages with the concave hole 21f of the lid body 21b. It is hanging. On the other hand, an annular magnet 41 having an inner diameter slightly larger than the outer diameter of the detection rod 40 is embedded in the upper end of the piston 22, and the piston 22 moves up and down so that the relative movement between the detection rod 40 and the magnet 41. The position is displaced and the sensor 38 emits a signal to notify the position of the feeder rod 29 integrated with the piston 22.

In this position detecting device, a magnetic field in the circumferential direction is generated in the detection rod 40 by applying an axial current pulse to the detection rod 40 which is also a magnetostrictive line from the sensor 38. In this case, a magnet fixed on part of the piston 22
Since 41 is located around the detection rod 40, the magnet 41
The magnetic field in the axial direction is applied only to the part of the above, and the oblique magnetic field is generated by the combination of the magnetic field in the circumferential direction and the magnetic field in the axial direction, and therefore, the twisting occurs in this part of the detection rod 40. This phenomenon is called the Wiedemann effect, but since this twist is a kind of vibration, ultrasonic waves propagate at the speed of sound on the detection rod 40 which is also a metallic magnetostrictive wire. Therefore, the position of the magnet 41 can be measured by measuring with the displacement sensor 38 the change in the propagation time of this ultrasonic wave that changes with the change in the position of the magnet 41, and as a result, the position of the piston 22. Therefore, the position of the feeder rod 29 can naturally be detected, and this position can be converted into an analog electric signal and output.

In FIG. 2, extrusion cylinders 42 are fixed to the top plate 5 on both sides of the feeder rod device 20, and the tip of the piston rod 43 faces the upper end of the cavity 13. By operating the extrusion cylinder 42, the product in the cavity 13 is extruded.

The operation of the injection molding machine configured as above will be described.
After the mold release agent is sprayed at the work station on the upstream side, the mold opening / closing unit 1 matched with the piston rod 4 of the mold opening / closing cylinder 3 with the core 9 closed closes the rotary table. The rotation causes the mold to circulate to the injection station, stops, and is clamped by the mold clamping cylinder. Next, the injection sleeve 14 into which the molten metal 15 has been injected is joined to the fixed sleeve 8, and the plunger 16 of the injection cylinder moves forward so that the molten metal 15 is injected into the cavity 13 through the molten metal passage 17. Immediately before or after the molten metal 15 is completely filled into the cavity 13, that is, before the molten metal 15 does not begin to solidify, oil is supplied from the oil inlet / outlet port 21d, so that the piston 22, the upper and lower piston rods 23 and 24, and the feeder rod 2 are supplied.
9 moves down integrally, and the tip of the feeder rod 29 is inserted into the melt 15 in the cavity 13. As a result, part of the molten metal 13 in the cavity 13 is removed and flows into the cavity 13 to perform a feeder action, so that the molten metal 15 spreads to every corner of the cavity 13. In this state, the molten metal 15 starts to solidify, and after a predetermined time, solidification is completed and the product is obtained. Therefore, when oil is supplied from the oil inlet / outlet port 21g, this oil is supplied to the lower side of the piston 22 through the inner hole of the guide rod 27, so that the piston 22 rises and the feeder rod 29 is removed from the cavity 13. . Thereafter, when the rotary table rotates 120 ° and the mold opening / closing unit 1 stops at the product take-out station, the piston rod 4 of the mold opening / closing cylinder 3 advances and the top plate 5 rises, so that the mold opening is performed, Since the core 9 is opened and the extrusion cylinder 42 is operated, the product is pushed by the extrusion pin 43 and taken out from the cavity 13.

During such a casting operation, cooling water is supplied from the water supply port 30d, and this supply water is discharged into the inner hole 29a of the feeder rod 29 through the inner hole of the cooling pipe 31, and then the annular shape. Since it enters the cooling passage 35 from the groove 36 and is discharged from the drain port through the annular groove 34, the cooling water passage 32, the annular groove 33 and the cooling water passage 37,
Feeder rod 29 and piston 22 and front and rear piston rods
Since 23 and 24 are cooled, they are not altered or damaged. Also, the vertical movement of the feeder rod 29 is detected by the detection rod.
Since it is controlled by the control device via the 40 and the displacement sensor 38, the operation of the feeder rod 29 is automatically stabilized and the molding conditions are stabilized. When controlling the feeder operation, if the stroke, which is the forward position of the feeder rod 29 with respect to time, is controlled to change along a predetermined curve, a good feeder effect is surely and easily obtained. Can be obtained.

In addition, although the present embodiment shows an example in which the present invention is applied to a rotary die casting machine, it is needless to say that the present invention can be applied to a stationary die casting machine as well, and is also applied to a plastic injection molding machine. be able to.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, in the feeder rod device of the injection molding machine, the cylinder portion fixed to the mold and the piston slidably fitted in the inner hole of the cylinder portion. , A rear piston rod that extends rearward from this piston and a front piston rod that extends forward from the piston form a double-sided piston type feeder cylinder that connects the feeder rod to the front piston rod, A cooling pipe is provided which extends from the rear end to the front end of the feeder rod and penetrates through the center thereof, and the cooling water passages which communicate with the cooling water supply port and the cooling water supply port inside and outside the cooling pipe, respectively. By providing the feeder rod device integrally with the feeder cylinder, the cooling water passage is provided through the piston rod, and the device can be housed in the hole of the mold. Therefore, the length of the entire device can be shortened compared to the conventional device in which the feeder rod device and feeder cylinder are connected in the axial direction, and the configuration is compact and the occupied space of the entire device is reduced. it can. Also,
Since the piston guide rod can be used also as an oil supply pipe without the need for piping in a movable part, the configuration is further simplified and maintenance and inspection are facilitated.

[Brief description of drawings]

1 and 2 show an example in which the feeder rod device of an injection molding machine according to the present invention is applied to a mold opening / closing unit of a rotary die casting machine, and FIG. 1 is a longitudinal sectional view of the feeder rod device. The figure is a vertical sectional view of a mold opening / closing unit in which this is performed. 1 ... Mold opening / closing unit, 6 ... Upper mold, 7 ... Lower mold,
13 …… cavity, 15 …… molten metal, 20 …… feeder rod device, 21 …… cylinder part, 21d, 21g …… oil inlet / outlet, 22 ……
Piston, 23 …… rear piston rod, 24 …… front piston rod, 25 …… feeder cylinder, 27 …… guide rod, 28 …… joint, 29 …… feeder rod, 30 …… block, 30d …… Water supply port, 30e ... Drainage port, 31 ... Cooling pipe,
32,35 …… Cooling water passage.

Claims (1)

[Claims] 1. Rotation is restricted by a cylinder part fixed to a mold and a hollow guide rod slidably fitted in an inner hole of the cylinder part and having a distal end communicating with a cylinder front chamber. A piston, a rear piston rod extending rearward from the piston, and a front piston rod extending forward from the piston and inserted into a through hole of a mold, forming a double-sided piston type feeder cylinder, and a tip portion Is connected to the front piston rod so that the feeder rod is inserted into and removed from the cavity of the mold, and reaches the front end portion of the feeder rod from the rear end portion of the rear piston rod to reach its center portion. A feeder rod device for an injection molding apparatus, characterized in that a cooling pipe passing therethrough is provided, and a cooling water passage communicating with a cooling water supply port and a cooling water passage respectively provided inside and outside the cooling pipe. .