JP2789802B2 - Feeder rod equipment for injection molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] 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 into a mold cavity to feed a feeder.

[Conventional technology]

For example, Japanese Patent Application Laid-Open No. 63-140747, which has been proposed as this type of injection molding apparatus, discloses a mold opening / closing unit of a rotary die casting machine for casting a disc wheel for automobiles made of aluminum or the like. It is configured as follows. That is, a movable mold is provided above a fixed mold fixed on the mounting plate, supported by a top plate that moves up and down by a mold opening / closing cylinder erected on the mounting plate. Between the molds, for example, four cores which are driven by a cylinder to advance and retreat in the radial direction are provided. A cavity is formed between the upper and lower molds and the closed core, and
A fixed sleeve having an inner hole communicating with the cavity is fitted through the hole of the mounting plate at the center of the fixed mold.

With this configuration, the mold opening / closing unit is supplied onto the rotary table to rotate the rotary table, stop at the injection station, clamp the mold, and then join the injection sleeve to the fixed sleeve to perform injection. When the molten metal pressed by the injection cylinder on the station side is injected into the cavity via both the injection and fixed sleeves, the solidified product is obtained. After that, the mold is opened and the product is taken out.

In such a die-casting machine, the molten metal may not spread to every corner of the cavity, and the quality of the product is deteriorated. Therefore, this mold opening / closing unit is provided with a feeder rod which moves into and out of the cavity by a driving device. Immediately before or immediately after the molten metal is injected and filled into the cavity, the molten metal is pushed by moving the feeder rod into the cavity, so that the molten metal spreads to every corner of the cavity, and a dense product is obtained. Can be

In the above, a conventional rigid mold injection molding machine equipped with a feeder rod has been described. A conventional horizontal clamp injection molding machine equipped with a feeder rod apparatus whose schematic sectional view is shown in FIG. The machine will be described. The fixed plate 51 and the movable plate 52 having the four corners connected by the tie rods 50 have a fixed mold 53 and a movable mold.
54 is fixed directly or via a spacer 55,
A cavity 56 is formed on the joint surface between the two dies 53 and 54. An injection cylinder 58 is inserted into an inner hole of an injection sleeve 57 fitted in the sleeve hole of the fixed platen 51 in communication with the cavity 56.
A plunger tip 60 connected to the piston rod 59 is fitted so as to be able to move forward and backward, and a molten metal injection hole 61 is opened in the injection sleeve 57. Reference numeral 62 denotes a mounting plate which advances and retreats by a not-shown extrusion cylinder, on which an extrusion plate 63 is supported via a plurality of loads 64. Facing the cavity 56 so as to move forward and backward.

With this configuration, the movable platen 53 is advanced by the driving device to clamp the movable mold 54 against the fixed mold 52, and after pouring from the pouring port 67, the piston of the injection cylinder 58 When the rod 59 is advanced, the molten metal is injected into the cavity 56. When the molten metal is solidified to become a product and the mold is opened, when the extrusion rod 65 is advanced, the product is extruded from the cavity 56 of the movable mold 54.

The feeder rod device generally denoted by reference numeral 66 is formed by a cylinder part 67 fixed to the side surface of the movable mold 54 and an oil feed rod 69 that moves forward and backward by supplying oil to the cylinder part 67, If the feeder rod 69 enters the molten metal before the molten oil is injected into the cavity 56 and solidified, the molten metal is pressurized and heated.

Further, the feeder rod device has a structure in which the cylinder portion 71 is fitted and supported in the hole of the fixed platen 51 and the feeder rod 72 is exposed to the molten metal as shown by a chain line 70 in FIG. There are also things.

[Problems to be solved by the invention]

However, among such conventional feeder rod devices, those exemplified as those provided in a firm-type injection molding machine use a piston rod of a feeder cylinder fixed to the upper surface of the top plate as described above. Since the feeder load is concentrically fixed via a coupling to the working end of the feeder rod through the hole of the top plate and protruded downward, the height of the entire feeder rod device is increased. Not only does the space occupied by the device increase, but also the reaction force of the firing force and the feeder force acts only on the feeder cylinder.The device is further enlarged to maintain strength, and the device is used to use special materials. Cannot be provided at a low cost.

Also, in the apparatus shown in FIG. 4, since the firing force and the reaction force of the feeder force act only on the feeder cylinder, there is also a problem that the entire apparatus becomes larger and expensive because special materials are used. is there.

The present invention has been made in view of the above points, and is a small-sized device that is capable of receiving the reaction force between the injection power and the feeder force by sharing it with a mold or a mold mounting plate holding the mold. It is an object of the present invention to provide an inexpensive feeder rod device for an injection molding device.

[Means for solving the problem]

In order to achieve such an object, in the present invention, a fixed mold mounting plate for holding a fixed die, and a movable mold for holding a movable die and moving forward and backward in the near-far direction with respect to the fixed mold mounting plate. A feeder rod device attached to an injection molding apparatus having a mold mounting plate is fitted into a bottomed cylindrical recess formed by opening the inner surface of the mold on the mold mounting plate side. A cylindrical cylinder portion having both end surfaces on both sides in contact with the inner surface of the mold mounting plate and the bottom surface of the concave hole, respectively, and a cylinder portion fitted into the inner hole of the cylinder portion and being fluidly pressured. A piston that is driven forward and backward in the axial direction of the piston, and a piston rod that has a feeder rod at its distal end that extends from the piston in the direction of the cavity between the two dies and that is inserted into and pulled out of the cavity by advance and retreat of the piston. It is formed by.

[Action]

According to the present invention, when the molten metal is filled in the mold cavity, and immediately before or immediately after the solidified material starts to be solidified, oil is supplied to the rear of the piston of the feeder cylinder, and the feeder rod integrated with the front piston rod of the feeder cylinder is provided. Is advanced and its tip enters the melt in the cavity, so that the riser is performed and the melt spreads to every corner of the cavity. The reaction force between the injection power and the feeder force can be received by sharing the cylinder part of the feeder cylinder, the mold, and the mold mounting plate.

〔Example〕

1 and 2 show an example in which a feeder rod device of the injection molding apparatus according to the present invention is applied to a mold opening / closing unit of a rotary die casting machine. FIG. 1 is a longitudinal sectional view of the feeder rod device. The figure is a longitudinal 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 supplied and mounted at positions that divide the outer peripheral portion into three equal parts in the circumferential direction. At the stop position of the mold opening / closing unit that stops rotating by 120 ° by intermittent rotation of 120 °, three work stations are defeated. Each mold opening / closing unit 1 has
At each of the three work stations, a mold clamping and injection, a mold opening and product removal, a mold cleaning and a spray of a mold release agent are provided at each of the three opening / closing units. Is performed, and one cycle is completed by one rotation of the turntable. The figure shows the mold opening / closing unit 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 drawing, a mold opening / closing unit 1 includes a mounting plate 2 fixed on a rotary table (not shown), and a piston which moves up and down by hydraulic pressure of a pair of mold opening / closing cylinders 3 provided on both right and left sides of the mounting plate 2. A horizontal plate-shaped top plate 5 is fixedly supported at the working end of the rod 4. And
The top plate 5 and a later-described upper mold 6 and the like are moved up and down by the advance and retreat of the piston rod 4, so that the mold is opened and the mold is set. The mounting plate 2 includes a substrate 7a, a side plate 7
b, a lower mold 7 disassembled and joined to the spacer 7c and the injection board 7d is fixed, and a cylindrical fixed sleeve 8 is fitted to the center of the lower mold 7. ing.

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 opening toward the top frame 5 which is a mating member of the upper mold 6, and a lower end face. A protruding portion 6b protruding downward from the central portion. Around the protruding portion 6b, a plurality of cores 9 divided in a circumferential direction are supported by the upper mold 5 via a support plate 10. It is provided to be supported by the piston rod 12 of the core cylinder 11. A cavity 13 is formed by the lower die 7, the upper die 6 to be clamped against the lower die 7, and the closed core 9. On the other hand, an injection sleeve 14 (not shown) on the side of an injection cylinder is detachably joined to the fixed sleeve 8, and after supplying the molten metal 15 to the injection sleeve 14, the plunger 16 is advanced so that the molten metal 15 is melted. road
It is configured to be injected into the cavity 13 via 17.

Next, a feeder rod device according to the present invention in which a main part is accommodated in the square-shaped concave hole 6a of the upper die 6 will be described. The feeder rod device, generally designated by the reference numeral 20, is a bottomed rectangular tube-shaped main body 21a fitted and fixed in the recess 6a, and a lower end opening of the main body 21a is closed so that the bottom end of the recess 6a contacts the bottom. A cylinder portion 21 having a lid 21b in contact therewith; a piston 22 slidably fitted in an inner hole 21c of the cylinder portion 21; and a rear piston rod 23 extending rearward with a flange portion bolted to the piston 22. And a front-end piston rod 24 extending from the piston 22 to the front. The front-end piston rod 24 slides on a bearing 26 bolted to the lid 21b. It is freely supported. Of the members constituting the feeder cylinder 25, the bottom plate 21c of the cylinder portion 21 is provided with an oil port 21d and an annular groove 21e communicating with the oil port 21d. A guide rod 27 formed in a hollow tubular shape and fixed to the bottom plate 21c of the cylinder portion 21 is slidably fitted in the plurality of rod holes 22a provided at equal positions in the circumferential direction of the piston 22. Has been
The distal end of the guide rod 27 is
The hollow cylindrical guide rod 27 is engaged with a concave hole 21f provided in the cylindrical portion 21b.
The upper and lower ends of the guide rod 27 communicate with the front chamber of the
21 g is provided, and is configured to supply oil to a lower side of the piston 22.

In addition, the inside of the tip of the tubular guide rod 27 is
When communicating with the front chamber 21, the distal end surface of the guide rod 27 may be disposed slightly away from the bottom plane of the concave hole 21 f as shown in FIG. Leave the tip surface in contact with the bottom plane of the recess 21f,
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 the rotation of the cylinder 22, and a role of moving the operating shaft into and out of the front chamber of the cylinder portion 21.

Further, a male screw portion 28a of a joint 28 is screwed into a female screw portion formed at a lower end portion of the front piston rod 24, and the other male screw portion 28b of the joint 28 is connected to the female screw portion of the oil press rod 29. It is screwed. And the piston
Hot water is supplied above or below 22, and the piston 22 of the oil feed cylinder 25 advances and retreats, so that the feeder rod 29 is inserted into and extracted from the cavity 13. The distal end face of the feeder rod 29 may be formed in an arc shape as shown in FIG. Also,
By rotating the joint 28, the entire length of the front piston rod 24 and the feeder rod 29 connected to the joint 28 by a screw action is adjusted.

In a hole 21h formed in the bottom plate 21c of the cylinder portion 21, a substantially square block 30 having a concave portion 30a, 30b, which is a member constituting a part of the cylinder 21, and engages the protrusion 30c. The bottom plate 21c and the block 30 are fixed with a plurality of bolts 30g. The upper end surface of the block 30 is formed so as to be flush with the upper end surface of the upper mold 6, and the upper end surface of the block 30 is formed of the top plate 5 that closes the upper end opening of the concave hole 6a. It is in contact with the lower surface. As a result, even if there is a concave hole 6a for installing the feeder rod device 20 in the upper die 6, the strength of this portion is sufficiently maintained. The block 30 is provided with a water supply port 30d and a drain port 30e that are connected to a cooling water source (not shown) by piping, and the rear piston rod 23 is engaged with a space 30f provided in the block 30. And the drain 30e is
It is communicated with the space 30f. Reference numeral 31 denotes a cooling pipe connected to the water supply port 30d.The cooling pipe 31 is provided at a lower end of the apparatus through a block 30 at an upper end of the apparatus, a rear piston rod 23, a piston 22, a front piston rod 24, and a joint 28. The feeder rod 29 extends through the axial center of the member up to the feeder rod 29, and its lower end is opened in the inner hole 29 a of the feeder rod 29. A cooling water passage 32 is provided between the piston 22, the piston rod 24, and the cooling pipe 31 so as to communicate with upper and lower annular grooves 33, 34.
A cooling water passage 35 is provided between the cooling water passage 31 and the upper and lower cooling water passages 31 so as to communicate with the upper and lower annular grooves 34 and 36. Further, a space between the space 30f and the annular groove 33 is communicated with a cooling water passage 38. 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, and
It turns and is discharged from the drain port 30e through the cooling water passages 35, 32, and 37. During this time, the feeder rod 29, the front piston rod 24, and the like are configured to be cooled by the cooling water. Note that the cooling pipe 31 is divided in the axial direction at the division surface 31a. The cooling pipe 31 may be a single pipe, or may be a double pipe and a slide type so that the length can be adjusted.

Reference numeral 38 denotes a displacement sensor fixed on the bottom plate 21c, which is connected to a control device via a lead wire 39.A detection rod 40 parallel to the guide rod 27 is fixed to the displacement sensor 38, It is hung so as to engage with the concave hole 21f of the body 21b. On the other hand, a detection rod is
An annular magnet 41 having an inner diameter slightly larger than the outer diameter of 40 is embedded, and the relative position between the detection rod 40 and the magnet 41 is displaced by the piston 22 moving up and down, and the sensor 38 emits a signal, The movement of the feeder rod 29 integrated with the piston 22 is controlled.

In this position detecting device, a circumferential magnetic field is generated in the detection rod 40 by applying an axial current pulse from the sensor 38 to the detection rod 40 which is also a magnetostrictive wire. In this case, a magnet fixed to a 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 portion (1), and an oblique magnetic field is generated by the combination of the magnetic field in the circumferential direction and the magnetic field in the axial direction. This phenomenon is called the Wideman effect. Since this torsion is a kind of vibration, ultrasonic waves propagate at the speed of sound on the detection rod 40 which is also a metallic magnetostrictive line. Therefore, the position of the magnet 41 can be measured by measuring the change in the propagation time of this ultrasonic wave, which changes with the change in the position of the magnet 41, by the displacement sensor 38. As a result, the position of the piston 22 can be measured. Therefore, naturally, the position of the feeder rod 29 can 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. The tip of the piston rod 43 faces the upper end of the cavity 13, and the product in the cavity 13 is extruded by operating the extrusion cylinder 42 after the mold is opened.

The operation of the injection molding machine configured as described above will be described. After the mold release agent has been sprayed at the upstream work station, the mold opening / closing unit 1 that has been mold-matched by retreating the piston rod 4 of the mold opening / closing cylinder 3 with the core 9 closed is mounted on the rotary table. The mold is closed by rotation,
It goes around to the injection station, stops, and is clamped by the clamping cylinder.

Next, the injection sleeve 14 into which the molten metal 15 is injected is joined to the fixed sleeve 8, and the plunger 16 of the injection cylinder is advanced, so that the molten metal 15 is injected into the cavity 13 through the molten metal passage 17. Immediately before or immediately after the molten metal 15 has been filled into the cavity 13, that is, before the molten metal 15 does not start to solidify, oil is supplied from the molten metal inlet / outlet 21d, so that the piston 22 and the upper and lower piston rods 23, 24 and the feeder rod 29 are The tip of the feeder rod 29 moves down integrally with the molten metal 15 in the cavity 13.
Is inserted into. As a result, a part of the molten metal 13 in the cavity 13 is removed and flows into the cavity 13 to perform a feeder operation, so that the molten metal 15 spreads in every corner of the cavity 13.

At the time of injection of the molten metal 15 and at the time of hot water feeding by the hot water rod 29, the reaction force between the injection power and the hot water force acts upward, but the lower surface of the lid 21b and the upper end surface of the block 30 The entire cylinder portion 21 including the block 30 is recessed in a state where the cylinder portion 21 is in contact with the upper end surface of the mold 7 and the lower surface of the top plate 5, respectively.
6a, that is, the entire cylinder portion 21 including the block 30 is sufficiently filled in the concave hole 6a of the upper mold 6, and these are in a state where they are solid. Therefore, the injection power, the hot water force and the reaction force thereof are received by the upper mold 6 with which the lower surface of the cylinder portion 21 abuts and the top plate 5 with which the upper surface of the block 30 abuts. Therefore, the upper mold 6 is not weakened or easily bent by the concave portion 6a, and has almost the same rigidity as that of an integrated body without the concave portion 6a, and The force is sufficiently maintained, and the mold and the mold fixing plate are hardly deformed, so that a good mold clamping state can be obtained.

In this state, the molten metal 15 starts to solidify, and after a predetermined time, the solidification is finished to obtain a product. Then, when oil is supplied from the extraction inlet 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 oil press rod 29 is pulled out of the cavity 13. . after this,
When the rotary table rotates 120 ° and the mold opening / closing unit 1 stops at the product removal station, the piston rod 4 of the mold opening / closing cylinder 3 moves forward and the top plate 5 rises, so that the mold is opened and the core 9 is opened. Is opened and the extrusion cylinder 42 operates, so that the product is pushed by the extrusion pin 43,
Removed from cavity 13.

During such a casting operation, cooling water is supplied from the water supply port 30d, and this supply water is discharged through the inner hole of the cooling pipe 31 into the inner hole 29a of the feeder rod 29, and then the annular water is supplied. The groove 36 enters the cooling passage 35, and the annular groove 34, the cooling water passage 32, the annular groove 33
And the water is discharged from the drain through the cooling water passage 37, so that the feeder rod 29, the piston 22, and the front and rear piston rods 23, 24 are cooled, and these are not deteriorated or damaged.

The vertical movement of the feeder rod 29 is detected by the detection rod 40 and the displacement sensor.
The feeder rod is controlled by the controller via 38
29 operation is automatically stabilized, and molding conditions are stabilized. When controlling the feeder operation, if the stroke, which is the advance position of the feeder rod 29 with respect to time, is controlled to change along a predetermined curve, a good feeder effect can be surely and reliably achieved. Obtained easily.

FIG. 3 is a schematic longitudinal sectional view of a main part of an injection molding machine showing an embodiment in which the present invention is applied to an injection molding machine of a horizontal clamping type, corresponding to FIG. Since the configuration is almost the same as that shown in FIG. 4, the same reference numerals are given and the description is omitted. In the figure, a fixed die 52 fixed to a fixed platen 51 is provided with a concave hole 52a opening to the fixed platen 51 side, and a feeder rod device 80 connects a cylinder portion 81 to the concave hole 52a.
The two ends are abutted on the bottom surface of the concave hole 52a and the inner vertical surface of the fixed platen 51, and the feeder rod 82 has the tip end facing the cavity 55.

1 and 2, the upper mold 6 is provided with a recess 6a so that the upper mold 6 is provided with a recess 6a.
Although the example in which the main part of the feeder rod device 20 is housed in 6a is shown, the fixing plate 5 is provided with a recess opening to the lower mold 5 side, and the main part of the feeder rod device 20 is provided in this recess. In any of these two embodiments of the firm injection molding machine and the two embodiments of the horizontal mold injection molding machine, the cylinder portion of the feeder rod device may have an axial line. Because the movement in the direction is regulated and housed in the concave hole, the injection power, the feeder force and the reaction force thereof are received by the mold and the mold mounting plate where both ends of the cylinder portion abut. Therefore, the feeder rod device can be made smaller and more compact, and the mold does not have weakness or is easily bent by the concave portion, and has almost the same rigidity as that without the concave portion. As a result, the mold clamping holding force is sufficiently maintained, Deformation of the mounting plate is also little, good clamping state can be obtained.

Further, although the present embodiment shows an example in which the present invention is applied to a rotary die casting machine, it goes without saying that the present invention can be applied to a stationary die casting machine in the same manner, and the same applies to an injection molding machine for plastics. be able to.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, a fixed mold mounting plate that holds a fixed die, and a movable die that holds a movable die and moves forward and backward with respect to the fixed die mounting plate. A feeder rod device attached to an injection molding apparatus having a mold mounting plate is fitted into a bottomed cylindrical recess formed by opening the inner surface of the mold on the mold mounting plate side. A cylindrical cylinder portion having both end surfaces on both sides in contact with the inner surface of the mold mounting plate and the bottom surface of the concave hole, respectively, and a cylinder portion fitted into the inner hole of the cylinder portion and being fluidly pressured. A piston that is driven forward and backward in the axial direction of the piston, and a piston rod that has a feeder rod at its distal end that extends from the piston in the direction of the cavity between the two dies and that is inserted into and pulled out of the cavity by advance and retreat of the piston. Thus, the following excellent effects can be obtained.

That is, according to the present invention, since the feeder rod device is integrated into the feeder cylinder and the device can be housed in the hole of the mold, the overall length of the device can be reduced. In addition, the configuration becomes compact, and the space occupied by the entire apparatus can be reduced.

Further, according to the present invention, the injection power, the feeder force, and the reaction force are adjusted by the mold (the bottom surface of the recess) and the mold in which both ends of the cylinder portion housed in the recess formed in the mold abut. Since the feeder rod can be received by the mounting plate, the feeder rod device can be made smaller and more compact, and the mold does not weaken or bend easily due to the recess.こ と に Having the same rigidity, the mold clamping holding force is sufficiently maintained, and the mold and the mold mounting plate are hardly deformed, so that a good mold clamping state can be obtained.

[Brief description of the drawings]

1 to 3 show an example in which a feeder rod device of an injection molding apparatus according to the present invention is applied to a mold opening / closing unit of a rotary die casting machine. FIG. 1 is a longitudinal sectional view of the feeder rod device. FIG. 3 is a longitudinal sectional view of a mold opening / closing unit in which this is implemented, FIG. 3 is a schematic longitudinal sectional view of a main part of a horizontal clamping injection molding machine in which the present invention is implemented as another embodiment of the present invention, and FIG. FIG. 4 is a schematic vertical sectional view of a main part of a conventional horizontal mold injection molding machine provided with a hot water rod device. 1 ... mold opening / closing unit, 5 ... top plate, 6 ...
Upper mold, 6a, 51a, 52a ... concave hole, 7 ... lower mold, 13 ... cavity, 15 ... molten metal, 20,80,83 ... feeder rod device,
21,81,84… Cylinder, 22… Piston, 23… Rear piston rod, 24… Front piston rod, 25… Feeder cylinder, 27… Guide rod, 29,82,85… Feeder rod, 30 …… Block.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B22D 17/22 B29C 45/17 B29C 45/26 B29C 45/57

Claims (1)

(57) [Claims] 1. A fixed mold mounting plate for holding a fixed mold,
A feeder rod device attached to an injection molding apparatus having a movable mold mounting plate that holds a movable mold and is driven forward and backward with respect to the fixed mold mounting plate. The end faces on both sides are respectively fitted to the inner surface of the mold mounting plate and the bottom surface of the concave hole, which are fitted and accommodated in the bottomed cylindrical recess formed in the inner surface on the mold mounting plate side. A cylindrical cylinder portion in contact with the piston; a piston fitted into an inner hole of the cylinder portion and driven to advance and retreat in the axial direction of the cylinder portion by fluid pressure; and extending from the piston in a cavity direction between the two dies. A feeder rod device for an injection molding apparatus, comprising: a feeder rod which is inserted into and withdrawn from the cavity by the reciprocation of the piston, and a piston rod provided at a distal end thereof.