JP3326514B2 - Injection molding apparatus and its injection unit and mold clamping unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding apparatus used for injection molding of plastics and the like.

[0002]

2. Description of the Related Art An example of this type of conventional injection molding apparatus is shown in FIGS. On one side of the upper surface 11a of the gantry 11 in the longitudinal direction, a movable base 12 which is movable on the upper surface 11a in the longitudinal direction is installed, and on the movable base 12, a driving unit 13 for injection and a driving source 14 are provided. Is installed. An injection cylinder 15 is mounted on the drive unit 13 so as to protrude toward the center in the longitudinal direction of the upper surface 11a, and a material hopper 16 is mounted on an upper portion of the injection cylinder 15 on the drive unit 13 side. A heater 17 is attached to the peripheral surface of the injection cylinder 15 except for the upper part. FIG.
As is clear from FIG. 7, a cooling jacket 71 is attached to a lower portion of the hopper of the injection cylinder 15. By constantly flowing a small amount of cold water such as city water through a pipe 81 through a cooling water passage 80 provided in the cooling jacket 71, the lower part of the hopper of the injection cylinder 15 is cooled and the temperature of this part is kept constant. ing.

In this example, a hydraulic pump is provided for a drive source 14, a hydraulic cylinder is provided for a drive unit 13, and a screw 4 connected to the piston is provided in an injection cylinder 15. .

At a substantially central portion of the upper surface 11a of the gantry 11,
A fixed die plate 19 is erected, and its plate surface faces the nozzle 18 at the tip of the injection cylinder 15.
On the other side in the longitudinal direction of 1 a, a support 21 is provided upright facing the fixed die plate 19. The fixed die plate 19 and the support base 21 have a substantially rectangular plate shape,
Both ends are supported at the four corners, respectively, and the upper surface 11a
The four tie bars 22 extending in the longitudinal direction are provided between the fixed die plate 19 and the support 21. The four tie bars 22 are provided with movable die plates 23 which are positioned and supported through four corners thereof so as to be movable in the axial direction thereof.

Each of the fixed die plate 19 and the movable die plate 23 is provided with a plurality of taps (not shown) for fixing and fixing the die.
A through hole (not shown) through which the nozzle 18 of the injection cylinder 15 is inserted is formed at the center of the nozzle.

[0006] The drive unit 24 for mold clamping is inserted into a mounting hole formed in the support table 21 to be mounted and supported on the support table 21. The drive unit 24 is provided with a hydraulic cylinder similarly to the drive unit 13 on the injection side. The drive source (hydraulic pump) for this hydraulic cylinder shares the drive source 14 on the injection side.

[0007] A fixed plate 25 is provided on the drive section 24 in connection with the piston of the hydraulic cylinder. A fixed plate 26 is attached to the movable die plate 23 so as to face the fixed plate 25. When the fixed plates 25 and 26 are fixed to each other, the movable die plate 23 is driven by the drive unit 24, whereby the movable die plate 23 is guided by the tie bar 22 and moves in the axial direction thereof.

[0008] The moving base 12 on the injection side includes a moving mechanism 27.
And a connecting rod 28 connected to the fixed die plate 19. That is, the moving base 12 is connected to the moving mechanism 27 that engages with the connecting rod 28 and moves in the axial direction, and the distal end of the connecting rod 28 is fixed to the fixed die plate 19. Therefore, the movable base 12 can be moved with reference to the fixed die plate 19. The moving mechanism 27 and the connecting rod 28 are constituted by a hydraulic cylinder and a shaft attached to its piston.

A control unit for driving and controlling each drive unit is accommodated in the gantry 11, and a control panel 29 is provided on the front of the gantry 11. An installation level pad 31 is attached to the bottom surface of the gantry 11. Also, the upper surface 1 of the gantry 11
As shown in FIG. 5 (a), a rail 32 is provided along the front edge of 1a, and a door 33 that moves along the rail 32 is provided. During the injection molding operation, a door 33 is positioned in front of both die plates 19 and 23 for safety measures. FIG. 5B shows the rail 32 and the door 3.
3 is omitted, and the door 33 is also shown in FIG.
The illustration of the frame that supports is omitted.

[0012] A hole 34 penetrating the gantry 11 in the front-rear direction is provided with an opening 3 formed in the upper surface 11a.
5 and a tray (not shown) for receiving an injection molded article falling through the opening 35 is provided in the hole 34.
Placed in

The injection molding device 36 constructed as described above
In the injection molding process, one of a pair of molds is attached to the fixed die plate 19 and the other is attached to the movable die plate 23, and the movable die plate 23 is moved by the driving unit 24, and the two molds are tightened together. This is performed by injecting the molding material into the mold by the cylinder 15.

[0012]

As described above, in the conventional injection molding apparatus 36, the movable die plate 2
3 is the same as the injection direction of the molding material from the injection cylinder 15, and the moving direction of the movable die plate 23 and the direction of the injection cylinder 15 are both fixed. It was impossible to change the direction of tightening the mold with respect to the direction.

Therefore, even if it is necessary to tighten the mold in the direction perpendicular to the injection direction of the molding material, for example, due to the shape and quality of the molded product, it cannot be performed. This is inconvenient, and good injection molding cannot be performed.

In the conventional injection molding apparatus, as described above, the temperature of the lower portion of the hopper of the injection cylinder 15 is adjusted by using city water or the like. Since it was not possible to cope with the temperature change of the cylinder 15, the temperature fluctuation of the lower portion of the hopper of the injection cylinder 15 could not be avoided. When the temperature of the hopper lower portion of the injection cylinder varies, changes the state biting into the screw of the molding material supplied through the hopper, variation kneading state of the molding material, will be thus molding condition varies, molded The products that were used had variations. In some high-precision injection molding machines, the flow rate of chilled water is controlled by opening and closing valves.However, even if the flow rate of chilled water is controlled in this way, the temperature of the lower part of the injection cylinder hopper is kept constant. I couldn't keep it.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the disadvantages of the prior art and to enable the selection of the direction in which the molding material is to be injected with respect to the injection direction of the molding material, and to significantly change the tightening direction with respect to the injection direction. It is an object of the present invention to provide an injection molding apparatus which can be easily performed and can keep a temperature of a lower portion of a hopper of an injection cylinder constant, and further provide an injection unit and a mold clamping unit which constitute the injection molding apparatus. It is in.

[0016]

According to the first aspect of the present invention, an injection unit having a hopper mounted thereon and a drive unit for driving the injection cylinder mounted on a gantry, and a fixed unit. A mold clamping unit including a die plate, a movable die plate facing the fixed die plate and movable, a driving unit for moving the movable die plate, and a lower portion of a hopper of the injection cylinder; And a control unit that sends an operation signal to the injection unit, the mold clamping unit, and the cooling unit. The injection unit, the mold clamping unit, and the cooling unit are connected to each other. An injection molding apparatus, wherein the mold clamping unit includes one end of the gantry in the moving direction of the moving die plate, and the moving direction. At one end of the gantry in the intersecting direction, each has a connecting portion to which the injection unit is connected, the cooling unit has a medium tank, the medium tank and the lower portion of the hopper of the injection cylinder of the injection cylinder While circulating a cooling medium therebetween, the cooling medium is air-cooled, and a transport device that facilitates movement of at least one of the injection unit and the mold clamping unit is provided on at least one of the pedestals. Thus, an injection molding apparatus characterized in that:

According to the second aspect of the present invention, the injection unit extends in the same direction as the injection cylinder, and a tip thereof is fixed to a connection portion of the mold clamping unit; A moving mechanism that engages and moves in the axial direction thereof; and a moving base that is connected to the moving mechanism. The moving base is movably disposed on a gantry of the injection unit. 2. The injection molding apparatus according to claim 1, wherein the injection cylinder and the drive section are mounted on the injection molding apparatus.

According to a third aspect of the present invention, there is provided the injection molding apparatus according to the first or second aspect, wherein the conveying device is an air ejection mechanism provided on a bottom surface of the gantry. Can be

According to the fourth aspect of the present invention, there is provided the injection molding apparatus according to any one of the first to third aspects, wherein the cooling unit is provided in the injection unit.

According to the fifth aspect of the present invention, the cooling unit includes a chiller pipe wound around an outer peripheral surface of the medium tank, a chiller medium filled in the chiller pipe, and a cooling unit in contact with the chiller pipe. The injection molding apparatus according to any one of claims 1 to 4, further comprising a fin and a blower for blowing air to the cooling fin.

According to the invention described in claim 6, the transport device
The mounting is provided on the bottom surface of the gantry.
An injection molding apparatus according to claim 1 is obtained.

[0022]

[0023]

1 to 4 show an embodiment of the present invention.
5 and 6 are denoted by the same reference numerals,
The description is omitted. The injection molding apparatus 40 of the present embodiment
It comprises an injection unit 41, a mold clamping unit 42, a cooling unit 70, and a control unit 43.

The injection unit 41 is a unit for injecting a molding material. The movable base 12 is movably disposed on the upper surface 44a of the gantry 44, and the drive unit 13 and the drive source 14 for injection are mounted on the movable base 12. The injection cylinder 15 is mounted on the drive unit 13. Injection cylinder 15
The extending direction of the moving base 12 and the moving direction of the moving base 12 are parallel to each other. A pair of connecting rods 28 extending in the moving direction are attached to the moving base 12 via moving mechanisms 27, respectively. As shown in FIG. 1A, the pair of moving mechanisms 27 are attached to the moving base 12 so as to be located on both sides of the injection cylinder 15.

At four corners on the bottom of the gantry 44, the injection unit 4
An air ejection mechanism 45 is provided as an example of a transport device that facilitates the movement of the vehicle 1. FIG. 2 shows the detailed structure of the air ejection mechanism 45. A rectangular plate-shaped base 46 is attached to the corner of the bottom of the gantry 44 by screws 47, and further, the disk-shaped back plate 4 is attached to the base 46.
8 is attached by screws 49. An accumulating pad 51 is attached to a surface of the back plate 48 opposite to the surface facing the base 46 by bonding. The accumulation pad 51 is, for example, a donut-shaped hollow body made of rubber or the like, and has a small hole 51a formed on the surface to be bonded to the back plate 48, and an annular hole formed concentrically with the center hole 51b on the surface on the opposite side. 51c are formed. A disk-shaped control pad 52 is provided on the surface of the accumulation pad 51 on which the annular hole 51c is formed, and a center pad 53 is provided therebelow. The control pad 52 has a large number of through holes 52a formed on the circumference thereof in opposition to the annular hole 51c of the accumulation pad 51. The center pad 53 is formed by a bolt 54 inserted on the center axis.
It is attached and fixed to the back plate 48 and the base 46 via the control pad 52 and the accumulation pad 51.

Through holes 46a and 48a are formed in the base 46 and the back plate 48, respectively. The hollow inside of the accumulator pad 51 and the coupler 55 attached to one side of the base 46 are formed through small holes 51a. These through holes 46a and 48a communicate with each other. A hose 56 is attached to the coupler 55, and the other end of the hose 56 is connected to a compressed air delivery source (not shown) such as a compressor. Incidentally, reference numeral 57 in FIG. 2 denotes a packing.

The air ejection mechanism 4 having the above structure
5 is supplied with compressed air, the annular hole 51 c of the accumulation pad 51 and the through-hole 52 of the control pad 52.
a, compressed air is radially ejected from between the control pad 52 and the center pad 53 (see FIG. 2,
Arrows indicate air flow). Therefore, 4 on the bottom of the gantry 44
If compressed air is supplied to each of the air ejection mechanisms 45 provided at the corners, the injection unit 41 can be slightly floated from the installation surface by the compressed air pressure ejected from them.

The mold clamping unit 42 is a unit for attaching a pair of molds and clamping them. As shown in FIG. 1, the fixed die plate 19 is mounted on the upper surface 61a of the gantry 61.
A support base 21 for supporting the drive unit 24 is provided upright, and a movable die plate 23 is attached to four tie bars 22 disposed therebetween. In this example, a hydraulic cylinder is disposed in the drive unit 24, and a drive source (hydraulic pump) for the hydraulic cylinder is housed in the gantry 61.

On the upper surface 61a of the gantry 61, the ends of the pair of connecting rods 28 of the ejection unit 41 are inserted and fixed to the ends on the fixed die plate 19 side in the moving direction of the movable die plate 23, respectively. A pair of block-shaped connecting portions 63 having holes 62 are provided, and a pair of connecting portions 63 is similarly provided at the end opposite to the door 33 in a direction orthogonal to the moving direction of the moving die plate 23. Have been. The fixing between the connecting portion 63 and the connecting rod 28 is performed by inserting the tip of the connecting rod 28 into the mounting hole 62 and locking them with a pin (not shown), for example. Similarly to the injection unit 41, air ejection mechanisms 45 as an example of a transport device that facilitates the movement of the mold clamping unit 42 are provided at the four corners of the bottom surface of the gantry 61, respectively.

The cooling unit 70 is, as shown in FIG.
Cooling jacket 71, medium tank 72, cooling medium 7
3, a pump 74, a chiller pipe 75, a chiller medium 76, a radiation fin 77, a blower 78, a heater 79
And a sensor 84. This cooling unit 7
0 is provided in the gantry 44 of the injection unit 41.

The cooling jacket 71 has a cooling water passage 80 and is mounted below the hopper 16 of the injection cylinder 15. The medium tank 72 is connected to the cooling water channel 80 by a pipe 81. The cooling medium 73 is water, oil, or the like, and is filled in the medium tank 72. The pump 74 circulates a cooling medium 73 between the cooling jacket 71 and the medium tank 72, and the cooling medium 73 cools a portion below the hopper 16 of the injection cylinder 15. The chiller pipe 75 is wound around the outer peripheral surface of the medium tank 72. The chiller medium 76 is filled in the chiller pipe 75. The radiating fins 77 are in contact with the chiller pipe 75, and the heat of the cooling medium 73 in the medium tank 72 is transmitted through the chiller medium 76.
7 The blower 78 includes an electric motor 82 which is a main part of the drive source 14 of the injection unit 41.
, And includes an electric motor 82 and a propeller 83 fixed to the rotating shaft. This blower 7
8 , cool air is supplied to the radiation fins 77,
The heat of the cooling medium 73 transmitted to the radiation fins 77 via the chiller medium 76 is radiated, and as a result, the cooling medium 73 is cooled. The heater 79 is provided in the medium tank 72, and its end is
It is pulled out of the medium tank 72. This heater 79
Heats the cooling medium 73 in the medium tank 72, thereby balancing the amount of heat released through the radiation fins 77 and the like and the amount of heat applied to the cooling medium 73 by the heater 79. It is designed to keep the temperature constant. The sensor 84 is provided in the injection cylinder 15, detects the temperature of the injection cylinder 15 below the hopper 16, and outputs a signal to the control unit 43.

The control unit 43 includes an injection unit 41,
An operation signal is sent to the mold clamping unit 42 and the cooling unit 70 to control them, and a controller 64 having a control panel 64a and a display unit 64b is mounted on the gantry 65. Note that a caster 66 is attached to the gantry 65.

The controller 64 is electrically connected to the injection unit 41 and the mold clamping unit 42 by cables 67, respectively. In addition, 68 in FIG.
69 is a unit 41,
42 shows a connector on the 42 side.

Next, the injection unit 41 and the mold clamping unit 4
2 will be described. When performing the injection molding by clamping the mold in the same direction as the injection direction of the molding material from the injection cylinder 15, the injection unit 41 and the mold clamping unit 42
Are arranged as shown in FIG. And both gantry 4
4 and 61 are brought close to each other, the moving base 12 of the injection unit 41 is moved to the mold clamping unit 42 side,
8 are fixed to the corresponding coupling portions 63 of the mold clamping unit 42, respectively. Thus, the injection cylinder 15 can be moved with reference to the connecting portion 63, that is, the position of the nozzle 18 can be controlled with respect to the mold clamped by the fixed die plate 19 and the movable die plate 23.

On the other hand, when the injection molding is performed by tightening the mold in a direction orthogonal to the injection direction of the molding material, the injection unit 41 is moved to have the arrangement shown in FIG. The movement of the injection unit 41 is easily performed by applying a slight force by supplying compressed air to each air ejection mechanism 45 attached to the gantry 44 and causing the entire injection unit 41 to float about several mm from the installation surface. be able to. Further, at this time, since the cooling unit 70 is unitized and incorporated in the injection unit 41, there is no need to perform piping between the lower portion of the hopper of the injection cylinder and the city water pipe as in the related art. Also in this respect, the movement of the injection unit 41 can be easily performed.

In this example, the air ejection mechanism 45 is provided in both the injection unit 41 and the mold clamping unit 42. However, in order to change the arrangement of the injection unit 41 and the mold clamping unit 42, either one of them is required. Air blowing mechanism 4 for unit
5 may be provided to move the unit. If the air ejection mechanism 45 is provided in both the ejection unit 41 and the mold clamping unit 42 as in this example, when the entire injection molding apparatus 40 is moved to another place, for example, the heavy injection unit 41, mold clamping unit 42
Can be easily moved.

In this example, a hydraulic pump and a hydraulic cylinder are used for each drive source and drive unit of the injection unit 41 and the mold clamping unit 42. For example, instead of these, a servomotor and a ball screw are used. In this case, a propeller may be attached to the rotation shaft of the servomotor to provide a blower for the cooling unit.

[0038]

As described above, according to the present invention, an injection unit is constituted by connecting an injection unit, a mold clamping unit, a cooling unit and a control unit. The connection status of the units can be changed. This makes it possible to select the direction in which the mold is to be tightened with respect to the injection direction of the molding material, that is, even in the case of molding using a mold that requires tightening in the same direction as the injection direction of the molding material, the direction orthogonal to the injection direction. Since it can be performed even by molding using a mold requiring tightening, it is versatile and easy to use.

When at least one of the injection unit and the mold clamping unit is moved in order to change the connection state between the injection unit and the mold clamping unit, it is a heavy object only by applying a slight force by the transport device. The unit can be moved, and the unit can be moved very easily. At this time, since the cooling unit is an air-cooled type, there is no pipe connecting the lower part of the hopper of the injection cylinder and the city water pipe as in the conventional case. Changes can be made easily. In addition, since the lower part of the hopper of the injection cylinder is cooled by the air-cooling type cooling unit, the temperature of this part can be kept constant, and as a result, variations in products can be eliminated.

In the conventional injection molding apparatus, for example, when exchanging the molding material, it takes time to remove and replace the old material in the injection cylinder and the hopper, and the molding process has to be stopped for a long time. However, in the present invention, since the injection molding apparatus can be separated into each unit, for example, another injection unit is prepared, and separately from the active injection molding apparatus, the injection unit is charged with the molding material to be exchanged by the external unit. If the injection unit is connected and exchanged, the molding material of the injection molding apparatus can be exchanged in a very short time, and the operation rate can be improved.

Further, if a plurality of mold clamping units having different mold clamping forces and injection units having different cylinder capacities are prepared,
Various combinations can be performed by the combination thereof.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the injection molding apparatus of the present invention,
(A) is a top view, (b) is a front view with a part omitted.

FIG. 2 is an enlarged sectional view showing details of an air ejection mechanism of the injection molding apparatus shown in FIG.

FIG. 3 is a plan view showing another connection state of the injection unit and the mold clamping unit in the injection molding apparatus shown in FIG.

FIG. 4 is a schematic structural view of a cooling unit of the injection molding apparatus shown in FIG.

5A and 5B show an example of a conventional injection molding apparatus, in which FIG. 5A is a plan view, and FIG.

6 is a schematic structural view of a cooling unit of the injection molding apparatus shown in FIG.

[Explanation of symbols]

 13 Drive Unit 15 Injection Cylinder 19 Fixed Die Plate 23 Moving Die Plate 24 Drive Unit 41 Injection Unit 42 Mold Clamping Unit 43 Control Unit 44 Mount 45 Air Jetting Mechanism 61 Mount 63 Connecting Unit 70 Cooling Unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 45/07 B29C 45/58 B29C 45/72

Claims (6)

(57) [Claims] 1. An injection unit having a hopper mounted thereon, an injection unit having a drive unit for driving the injection cylinder mounted on a mount, a fixed die plate, and a movable die facing the fixed die plate. A movable die plate, a mold clamping unit having a driving unit for moving the movable die plate mounted on a gantry, a cooling unit for cooling a lower portion of a hopper of the injection cylinder, the injection unit, and the mold clamping unit. A control unit that sends an operation signal to a unit and a cooling unit, wherein the injection unit, the mold clamping unit, and a cooling unit are connected to each other, and the injection molding apparatus is configured. One end of the gantry in the moving direction of the moving die plate, and one end of the gantry in a direction orthogonal to the moving direction. The cooling unit includes a connecting portion to which the injection unit is connected, the cooling unit includes a medium tank, and the cooling medium is circulated between the medium tank and a lower portion of a hopper of the injection cylinder. An injection molding apparatus characterized in that a transport device that facilitates movement of at least one of the injection unit and the mold clamping unit is provided on at least one of the pedestals. 2. The injection unit extends in the same direction as the injection cylinder, a tip of which is fixed to a connection portion of the mold clamping unit; And a moving base connected to the moving mechanism. The moving base is movably arranged on a gantry of the injection unit, and the injection cylinder and the driving unit are mounted on the moving base. 2. The injection molding apparatus according to claim 1, further comprising: 3. The injection molding apparatus according to claim 1, wherein the transport device is an air ejection mechanism provided on a bottom surface of the gantry. 4. The injection molding apparatus according to claim 1, wherein the cooling unit is provided in the injection unit. 5. The cooling unit includes: a chiller pipe wound around an outer peripheral surface of the medium tank; a chiller medium filled in the chiller pipe; a cooling fin in contact with the chiller pipe; and a cooling fin. The injection molding apparatus according to any one of claims 1 to 4, further comprising a blower for blowing air. 6. The transportation device is provided on a bottom surface of the gantry.
2. The injection molding apparatus according to claim 1, wherein
Place.