JP2000117793A - Injection apparatus and method for molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection apparatus and a method of a molding machine, wherein the injection pressure accuracy is improved and a constant molding quality is obtained in a molded article. SOLUTION: A fluidity adjusting device 201 is provided, which makes fluidity of a molten resin material 115 in the vicinity of a piston portion 107 worse than fluidity of the molten resin material in a cylinder 105, and that the fluidity of the cylinder and the piston portion is reduced. Gap 11
9 so as to reduce the intrusion of the molten resin material into the fluid. Therefore, sticking and clogging of the resin material to the inner surface of the cylinder, sliding resistance of the piston portion can be reduced, and injection pressure accuracy can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection device of a molding machine for melting a resin material, pressurizing the resin material, and injecting the resin material into a mold, for example, for molding a resin gear or a package of an electronic component. Related to the injection method performed in the above.

[0002]

2. Description of the Related Art As one type of injection device of a molding machine as described above, a pre-plasticization type using an injection device 1 shown in FIG. 4 is known. The injection device 1 includes a barrel 3 into which a resin material 7 serving as a material of a molded body is supplied, and a screw 2 which is fitted in the barrel 3 along the barrel 3 and melts while transporting the resin material 7. A cylinder having a plunger 6 connected to the barrel 3 and slidable therein, wherein the molten resin material 115 supplied by the screw 2 is provided.
And a cylinder 5 for injecting the same into the mold by the plunger 6.

[0003]

In the above-described injection apparatus 1, it is required that the molten resin material 115 be injected into a mold at a constant pressure without variation. However,
In such an injection device 1 of a conventional molding machine, the resin material 115 that has entered the gap 8 between the cylinder 5 and the plunger 6
Sticks to the inner surface 5a of the cylinder 5 to increase the resistance when the plunger 6 slides in the cylinder 5, or the resin material 115 leaking to the rear of the plunger 6 in the moving direction of the plunger 6 for injection. There is a problem in that the injection pressure fluctuates due to clogging in the cylinder 5 and constant molding quality cannot be obtained in the molded body. The present invention
An object of the present invention is to provide an injection apparatus and a method of a molding machine that can increase injection pressure accuracy and obtain a constant molding quality in a molded article. With the goal.

[0004]

In the injection device of a molding machine according to a first aspect of the present invention, a piston portion of a plunger slides on an inner surface of a cylinder accommodating a molten resin material for molding a molded product. An injection device of a molding machine that injects the molten resin material from the cylinder by moving to an outlet side, wherein the fluidity of the molten resin material in the vicinity of the piston portion is controlled by the other molten resin material in the cylinder. It is characterized by having a fluidity adjusting device that makes the fluidity worse than the fluidity and reduces the intrusion of the molten resin material into the gap between the cylinder and the piston portion.

In the injection method of a molding machine according to a second aspect of the present invention, the piston portion of the plunger slides on the inner surface of a cylinder for accommodating a molten resin material for molding a molded body toward the injection port. The injection method of a molding machine for injecting the molten resin material from the cylinder by making the fluidity of the molten resin material near the piston portion worse than the fluidity of the molten resin material in the cylinder. The fluidity is adjusted so as to reduce the intrusion of the molten resin material into the gap between the cylinder and the piston portion.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An injection device of a molding machine and an injection method executed by the injection device according to an embodiment of the present invention will be described below with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals.
In the present embodiment, a cooling device is taken as an example that fulfills the function of the “fluidity adjusting device” described in the above “Means for Solving the Problems”. However, it is not limited to this. The injection device of the present embodiment is provided in a molding machine for molding a package of an electronic component.
Of course, it is not limited to this.

In the present embodiment, a case where the resin material 7 as a material of the molded body molded by the molding machine is a thermosetting resin material will be taken as an example. In the present embodiment shown in FIG. 1, the injection device 101 of the molding machine includes a screw 102,
Barrel 103, cylinder 105, plunger 106
, A fluidity adjusting device 201 and a control device 180. The cylindrical barrel 103 is supplied with the resin material 7 serving as the material of the molded body molded by the molding machine, and the inside of the barrel 103 extends along the direction in which the barrel 103 extends. The screw 102 is fitted around the axis thereof in a rotatable state by a driving device 111 such as a motor. A band heater 112 for heating the barrel 103 to almost the melting temperature of the resin material 7 by a heating device 113 is wound around the outer surface of the barrel 103. Therefore, the resin material 7 supplied to the barrel 103
The heating by the band heater 112 and the screw 10
Melting occurs in the barrel 103 due to shear heat generated in the barrel 103 due to the rotation of 2, and is supplied into the cylinder 105 as a molten resin material 115.

A plunger 1 having a piston portion 107 which slides on the inner surface of the cylinder 105
06 is fitted, and the plunger 106 can be moved along the cylinder 105 by a driving device 114 such as an air cylinder. Therefore, when the plunger 106 moves toward the injection port 108 side of the cylinder 105, the molten resin material 115 stored in the cylinder 105 is pressurized and injected from the injection port 108 into a mold (not shown). The cylinder 105 is provided with a molten resin material 115 in the piston section 10.
In order to enter the gap 119 between the cylinder 7 and the cylinder 105 and to discharge the solidified solidified resin material 116, a discharge opening 117 is formed on the side opposite to the injection port 108 in the moving direction of the piston portion 107. I have. In addition, the piston part 107 moves within a range indicated by reference numeral 230 in FIG. Although the discharge opening 117 is provided only in a part of the circumferential direction of the cylinder 105, the diameter of the plunger 106 is smaller than the diameter of the piston portion 107 as shown in the figure, Even when the solidified resin material 116 is formed just behind the discharge opening 117, the solidified resin material 116
Through the gap 231 between the plunger 5 and the plunger 106, it can be guided to the discharge opening 117 and can be discharged. In the present embodiment, the inner diameter of the cylinder 105 is 15 mm, the diameter of the injection port 108 is 10 mm, the size of the discharge opening 117 is 20 × 30 mm, the diameter of the piston 107 is 18 mm, and the cylinder of the piston 107 is 105
Is 20 mm in length. The temperature of the molten resin material 115 in the cylinder 105 is about 90 ° C. when the molten resin material 115 is a thermosetting epoxy resin.
It is.

Further, as one of the characteristic features of the present embodiment, the cylinder 105 has the piston 10
7 is provided with a cylinder cooling passage 212 at a position corresponding to the above-mentioned movement range, and a coolant 216, for example, water, oil, air, or the like, is supplied from the cylinder coolant supply device 213 to the cylinder cooling passage 212. The refrigerant 216 passes through the cylinder cooling passage 212 and is discharged to the outside of the cylinder 105. Therefore, a portion of the cylinder 105 corresponding to the moving range is cooled. In FIG. 1,
Cylinder cooling passage 212 in cylinder 105
Shows a case of a single cavity formed along the periphery of the cylinder 105, but is not limited to this form. For example, even if a passage is formed spirally along the periphery, Good, and also a cylinder cooling passage 2
A well-known form such as providing fins along the above passage so that the cylinder 12 can cool the cylinder 105 more efficiently can be adopted. Also, in FIG.
2 is formed in the cylinder 105, but is not limited to this, and may be formed around the outer periphery of the cylinder 105. On the other hand, a heater 121 for heating the cylinder 105 to a substantially melting temperature by the heating device 120 is attached to the connection portion of the barrel 103 and the injection port 108 portion.

Further, the piston portion 107 of the plunger 106 is provided with a piston cooling passage 214 as one of the characteristic features of the present embodiment, and the piston cooling passage 214 is provided in the piston cooling passage. 215
Supplies refrigerant 216, for example, water, oil, air and the like.
The refrigerant 216 passes through the piston cooling passage 214 and is discharged to the outside of the piston portion 107, that is, to the outside of the cylinder 105. Therefore, the piston 107 is cooled. In FIG. 1, the piston cooling passage 214 in the piston portion 107 shows a simple U-shape, but is not limited to this form.
For example, a passage may be formed in a spiral shape or the like along the axial direction of the plunger 106.
A well-known form such as providing a fin along the above-mentioned passage so that the piston 14 can cool the piston portion 107 more efficiently can be adopted.

In this embodiment, the entire cylinder 105 and plunger 106 are formed using hot die steel SKD61 specified in JIS (Japanese Industrial Standard).
However, in order to increase the cooling efficiency, the plunger 10
In 6, for example, only the piston portion 107 may be formed of a material having good thermal conductivity, and in the cylinder 105, for example, only a portion corresponding to the moving range may be formed of a material having good thermal conductivity. Further, the driving device 11 described above
1, heating device 113, driving device 114, heating device 12
0, each of the cylinder coolant supply device 213 and the piston coolant supply device 215 is connected to the control device 180, and the control device 180 controls the operation.

In this embodiment, the cooling device 211 is composed of the above-described cylinder cooling passage 212 and the cylinder coolant supply device 213, and the piston cooling passage 214 and the piston coolant supply device 215. However, unlike the present embodiment, it is not always necessary to provide the cooling device 211 on both the cylinder 105 side and the piston portion 107 side, and it is sufficient to provide the cooling device 211 on at least one side, preferably on the piston portion 107 side.

[0013] The cooling device 211 configured as described above includes:
The operation is controlled by the control device 180 and operates as follows. As described above, the molten resin material 115 housed in the cylinder 105 is heated by the heater 121, but at least the piston 107 is cooled by the cooling device 211, so that the vicinity of the piston 107 is Of the molten resin material 115
The liquidity is worse than that of. On the other hand, microscopically,
Since the gap 119 exists between the piston 107 and the inner surface 105a of the cylinder 105, the molten resin material 115 can enter. However, as described above, the piston portion 1
Since the molten resin material 115 existing near 07 has poor fluidity or is solidified, it is difficult or impossible to enter the gap 119.
Further, the molten resin material 115 that has entered the gap 119 does not stick to the inner surface of the cylinder 105. Therefore, the cooling device 211 can reduce the problem that has conventionally occurred, that is, the problem that the resin material entering the gap sticks to the inner surface of the cylinder and the resistance when the plunger slides in the cylinder increases. In addition, it is possible to improve the accuracy of the injection pressure and obtain a constant molding quality in the molded body.

The cylinder 105 and the piston 10
The temperature of the refrigerant 216 of the cooling device 211 on the seventh side is lower than the temperature of the molten resin material 115 compared to the molten resin material 115.
Is the temperature at which 18 can be generated. Specifically, in the present embodiment, water is used as the refrigerant 216, and the temperature is 20 to
It is 40 ° C, preferably 30 ° C. In the present embodiment, the temperature of the refrigerant 216 of the cooling device 211 on the cylinder 105 side and the piston 107 side is the same, but they may be different. The molten resin material 11
The viscosity of No. 5 is about 1,000 to 10,000 poise, and the viscosity of the molten resin material 118 is not less than poise.

Further, since the discharge opening 117 is provided in the cylinder 105 as described above, the molten resin material 115 or the molten resin material 118 intrudes into the gap 119 to be solidified and solidified. Even when the material 116 becomes the material 116, the solidified resin material 116 is removed from the cylinder 10 through the discharge opening 117.
5 can be discharged to the outside, so that the gap 109 between the cylinder 105 and the plunger 106 is not clogged.
Therefore, the occurrence of the problem that the resistance increases when the plunger 106 slides in the cylinder 105 is reduced, and the accuracy of the injection pressure can be increased to obtain a constant molding quality in the molded body.

Plunger 10 in the above-described embodiment
In 6, the coolant was supplied as a method of cooling the piston 107, but the method is not limited to this. That is, instead of the plunger 106 and the cooling device 211 described above, the plunger 131 and the other end cooling device 221 shown in FIG. 2 may be provided. The other configuration is the same as that of the injection device 101 shown in FIG. 1, and the description is omitted here. The plunger 131 has a hole 132 extending in the axial direction to the piston 107 along the axial direction.
A heat pipe 133 is inserted into the hole 132 as a heat removal material. One end 133a of the heat pipe 133 is located at the piston 107 and the other end 13a.
3b is provided with fins 134 for air cooling. or,
An opening 135 is formed in the heat pipe 133 in a direction perpendicular to the axial direction of the heat pipe 133 so as to correspond to the other end 133 b provided with the fin 134.
33 is formed. The opening 135 is disposed so as to correspond to the above-described discharge opening 117 of the cylinder 105, and the other end cooling device 2 is provided outside the cylinder 105 and at a position corresponding to the discharge opening 117.
A blower 21 is provided.

With such a configuration, the piston 1
07 is absorbed by one end 133a of the heat pipe 133 and is transmitted from the one end 133a to the fin 134 of the other end 133b via the heat pipe 133. Since the heat of the fins 134 and the other end 133b is removed by the blower, the heat removal and cooling of the piston 107 are performed via the heat pipe 133. still,
In the above embodiment, the example in which the heat pipe 133 is used as a means for transmitting the heat of the piston portion 107 has been described. However, the present invention is not limited to this, and a material having good heat conductivity, such as copper or aluminum, may be used. Is also good. Also fin 1
Although the cooling of the 34 and the other end 133b is performed by air cooling, other methods such as water cooling may of course be used. As described above, since the piston 107 is cooled by using the heat removal material and the other end cooling device 221, the cooling device 21 described above is used.
As in the case where No. 1 is used, the accuracy of the injection pressure can be increased and a certain molding quality can be obtained in the molded body.

In the above description, a thermosetting resin material is taken as an example of the resin material, but a thermoplastic resin material may be used. Even in the case of injecting a thermoplastic resin material, as in the case of the thermosetting resin described above, from the viewpoint of preventing the resin material from entering the gap between the piston portion 107 and the cylinder 105, The piston portion 107 is cooled in order to deteriorate the fluidity of the thermoplastic resin material in the vicinity. That is, when a thermoplastic resin material is used, the temperature in the molten state is about 200 to 400 ° C., and thus the piston 107 is cooled using pressurized and heated water or oil at about 140 ° C.

[0019]

As described above in detail, according to the injection device of the molding machine according to the first aspect of the present invention and the injection method according to the second aspect of the present invention, the injection device is provided with a fluidity adjusting device, and the molten resin material in the vicinity of the piston is provided. The fluidity is made worse than the fluidity of the molten resin material in the cylinder, and the fluidity is set to reduce the penetration of the molten resin material into a gap between the cylinder and the piston portion. Therefore, the resin material sticks to the inner surface of the cylinder or causes clogging of the injection pressure, and the sliding resistance of the piston portion in the cylinder can be reduced. Molding quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an injection device of a molding machine according to an embodiment of the present invention.

FIG. 2 is a diagram showing another example of the plunger and the cooling device shown in FIG.

FIG. 3 is a view showing another embodiment of the injection device shown in FIG. 1;

FIG. 4 is a view showing an injection device of a conventional molding machine.

[Explanation of symbols]

101: injection device, 105: cylinder, 106: plunger, 107: piston part, 115: molten resin material, 11
Reference Signs List 6: solidified resin material, 117: discharge opening, 119: gap, 201: fluidity adjusting device, 212: cylinder cooling passage, 213: cylinder refrigerant supply device, 214: piston cooling passage, 215: piston Refrigerant supply device, 2
16: refrigerant, 221: other end cooling device.

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Shinji Sakuriku 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Yuichi Nakajima 1006 Kazuma Kadoma, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. 4F206 AA36 AM03 AR18 AR20 JA07 JD05 JM01 JM12 JQ34 JQ48

Claims (10)

[Claims] A molten resin material (1) for molding a molded body.
15) An injection device of a molding machine for injecting the molten resin material from the cylinder by moving the piston portion (107) of the plunger (106) toward the injection port side by sliding on the inner surface of the cylinder (105) accommodating the cylinder. Wherein the fluidity of the molten resin material in the vicinity of the piston portion is made worse than the fluidity of the other molten resin material in the cylinder, and the fluidity of the molten resin material into the gap (119) between the cylinder and the piston portion is reduced. An injection device for a molding machine, comprising: a fluidity adjusting device (201) for making the molten resin material less fluid to enter. 2. When the molten resin material is thermosetting,
The injection device according to claim 1, wherein the fluidity adjusting device includes a cooling device (211) that cools the piston portion to make the molten resin material fluid so that penetration into the gap is reduced. 3. The piston cooling passage (214) through which a refrigerant (216) passes through the piston portion.
The injection device according to claim 2, further comprising a piston coolant supply device (215) that supplies the coolant to the piston cooling passage. 4. A cooling device, comprising: a rod-shaped heat removing material having one end inserted into the piston portion; and a cooling device provided at the other end of the heat removing material for cooling the other end. The injection device according to claim 2, further comprising: a second end cooling device (221) for cooling the part. 5. The cooling device according to claim 1, wherein said cooling device is provided corresponding to a moving range of said piston.
The injection device according to claim 3 or 4, further comprising a cylinder cooling passage (212) through which (6) passes, and a cylinder refrigerant supply device (213) for supplying the refrigerant to the cylinder cooling passage. 6. The cylinder discharges a solidified resin material (116) in which the molten resin material enters the gap and solidifies, so that the cylinder discharges to a reflection exit side of the moving range in the moving direction of the piston portion. The injection device according to any one of claims 1 to 5, further comprising an opening for use (117). 7. A molten resin material (1) for forming a molded body.
15) An injection method of a molding machine for injecting the molten resin material from the cylinder by moving the piston portion (107) of the plunger (106) toward the injection port side by sliding on the inner surface of the cylinder (105) accommodating the cylinder. The fluidity of the molten resin material in the vicinity of the piston portion is made worse than the fluidity of the molten resin material in the cylinder, and the molten resin material flows into a gap between the cylinder and the piston portion. An injection method for a molding machine, wherein the injection is adjusted to a fluidity that reduces intrusion. 8. When the molten resin material is thermosetting,
The injection method according to claim 7, wherein the fluidity adjustment is performed by cooling the piston portion so that the molten resin material has fluidity such that penetration into the gap is reduced. 9. The injection method according to claim 8, wherein the cooling of the piston portion is performed by supplying a coolant to the piston portion. 10. The injection method according to claim 8, wherein the fluidity adjustment uses cooling of a movement range of the piston portion in the cylinder.