JP3089204B2 - Screw type injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw type injection molding apparatus for kneading and melting a resin and injecting it into a mold.

[0002]

2. Description of the Related Art First, an in-line screw type injection molding apparatus which is a typical conventional injection molding apparatus will be described.

As shown in FIGS. 13 (a) and 13 (b), a heating cylinder 101, a cylinder head 105 which is detachably fixed to a tip of the heating cylinder 101 by bolts 110, a heating cylinder 101 and a cylinder head 1 are shown.
05 for heating the respective 05
A screw 102 having a conical screw head 104 is provided at a tip end surface 104b of the heating cylinder 101 so as to be rotatable and axially movable. A backflow prevention ring 109 is provided at a small diameter portion 104a of the screw head 104. The small diameter portion 104a and the screw 102
A pusher 107 is disposed at the boundary with the front end of the push button.

In the plasticizing step, the heating cylinder 10
The resin supplied from a hopper (not shown) disposed on the rear end side of the unit 1 is kneaded and melted by heating by a heater 103 and shearing heat while being transferred forward by a rotating screw 102. Then, as shown in FIG. 13A, the backflow prevention ring 109 moves forward due to the pressure of the resin transferred to the front to open the resin flow path in the cylinder, and the molten resin flows into the rear end face of the backflow prevention ring 109. 109a
From the gap between the inner wall of the backflow prevention ring 109 and the small-diameter portion 104a through the notch 104c, passes between the tip end surface 104b of the screw head 104 and the cylinder head 105, and is stored in the reservoir 108.
As the amount of molten resin stored in the reservoir 108 increases, the pressure causes the screw 102 to retreat while rotating and stop at that position when it reaches a predetermined amount.

[0005] In the injection and pressure-holding step, as shown in FIG. 13 (b), the molten resin in the reservoir 108 is injected into the injection nozzle 106 by advancing the screw 102.
Is injected into the mold through a screw.
As the molten resin in the reservoir 108 is compressed and the pressure increases, the backflow prevention ring 109 recedes, and the rear end surface 109a abuts against the pusher 107, so that the molten resin flows to the screw side, that is, the backflow is prevented. You.

Next, a conical screw type injection molding apparatus will be described.

[0007] As shown in FIG.
6, a conical screw 204 rotatably disposed in the heating cylinder 201, and a hole 203 extending in the axial direction provided at the center of the conical screw 204. , The hole 203
A cylindrical member 209 slidably disposed in the axial direction in the inside,
An injection piston 202 is provided in the cylindrical member 209 so as to be slidable in the axial direction.

In the plasticizing step, the cylindrical member 209
To the reservoir 2 from the conical screw 204 side.
In step 08, the molten resin is brought into a movable state, and the injection piston 202 is retracted to a predetermined position. The injected resin is fed into the spiral screw groove 20 of the rotating conical screw 204.
While being conveyed toward the center by 5, the mixture is kneaded and melted, and the molten resin is stored in the reservoir 208.

In the injection step, after the cylindrical member 209 is advanced and its front end is brought into contact with the inner wall surface of the injection nozzle 206, the movement of the molten resin from the conical screw side into the reservoir 208 is interrupted. The molten resin stored in the reservoir 208 is injected and filled into a mold (not shown) by advancing the 202.

[0010]

However, in the above-mentioned in-line screw type injection molding apparatus, during the injection and pressure-holding step, the backflow prevention ring 109 starts retreating and the rear end face 109a comes into contact with the pusher 107. In addition, it is impossible to prevent the molten resin from flowing backward through the gap between the rear end face 109a and the presser 107. Also, depending on the pressure difference of the molten resin applied to the front end face 109b and the rear end face 109a of the backflow prevention ring 109, the rear end face 109a
There is a possibility that a gap may be formed between the pressing resin 107 and the molten metal and the molten resin may flow backward. As a result, there is a problem in that the amount of resin injected and filled from the injection nozzle 106 varies, and the quality of the molded product also varies.

Further, after the plasticizing step is completed, the screw 10
At the point in time when 2 stops, the molten resin pressure in the screw groove 102a is higher than the molten resin pressure in the reservoir 108 (because the resin flows from a higher pressure to a lower pressure). For this reason, the screw groove 10
The molten resin in 2a flows into the reservoir 108 through the gap between the small diameter portion 104a and the inner wall of the backflow prevention ring 109. Then, there is a problem that the resin density in the reservoir 108 changes due to the variation in the amount of resin flowing into the reservoir 108, and the amount of injected resin, and eventually the quality of the molded product, varies.

On the other hand, the conical screw type injection molding apparatus can avoid the backflow of the molten resin during the injection and pressure holding process as in the above-described in-line screw type injection molding apparatus, but has the following problems.

[0013] The temperature distribution of the molten resin stored in the reservoir 208 may become unstable due to the large screw outer diameter in the screw cross-sectional direction. However, controlling the temperature distribution in the screw cross-sectional direction is difficult. It's not easy.

[0014] It is difficult to control the axial temperature distribution of the molten resin stored in the cylindrical member 209 constituting the reservoir 208 by the retreat of the injection piston 202, and the heating cylinder 201 has a conical shape. The contact state of the heater becomes unstable and the screw groove 20
Control of the resin temperature in 5 also becomes difficult.

Since the conical screw 204 is conical, processing costs are high, and in addition, a large-diameter injection piston is required, which increases manufacturing costs.

When an injection means for injecting a gas or an additive or a suction means for vacuum suction is attached to the outer wall surface of the heating cylinder 201 to inject a gas or an additive or vacuum suction, these means are rotated. Since the relative position of the spiral screw groove 205 of the conical screw 204 changes, stable gas or additive injection or vacuum suction cannot be performed.

Since the conical screw 204 has a large outer diameter, the power required to rotate it is large.

Since the state of the molten resin immediately before flowing into the reservoir 208 cannot be precisely controlled, the state of the molten resin stored in the reservoir 208 becomes unstable.

The present invention has been made in view of the above-mentioned problems, and it is possible to reliably prevent the backflow of the molten resin from the reservoir toward the screw groove at the start of the injection and pressure-holding step. It is possible to prevent the molten resin from flowing from the screw groove toward the reservoir between the time of completion and the start of the injection and pressure-holding process, and to precisely control the state of the resin immediately before flowing into the reservoir. It is an object of the present invention to realize a screw-type injection molding apparatus capable of performing the following.

Another object of the present invention is to provide a screw-type injection molding apparatus capable of reliably and easily injecting a gas or an additive or vacuum suction, a method of measuring the temperature of a molten resin stored in a reservoir in an axial direction and a sectional direction. It is an object of the present invention to realize a screw-type injection molding apparatus capable of easily controlling a temperature distribution.

[0021]

In order to achieve the above object, a screw type injection molding apparatus according to the present invention comprises a heating cylinder having a cylinder head removably fixed to a tip end thereof, and a cylinder head and the heating cylinder. A heating means for heating each, a screw having a screw head at a distal end disposed rotatably and axially retractable in the heating cylinder, and slidably disposed in the cylinder head; A screw-type injection molding apparatus comprising a torpedo and a torpedo linear drive means for moving the torpedo forward and backward in the axial direction, wherein the torpedo is such that the screw head is slidably inserted in a circumferential direction and an axial direction. A through-hole penetrating in the axial direction, and a seal portion provided at a portion of the distal end surface surrounding the opening periphery of the through-hole. The outer wall surface has a plurality of axially extending outer wall grooves formed at intervals in the circumferential direction, and the torpedo is retracted to separate the seal portion from the conical inner wall surface of the cylinder head. When done
The reservoir formed by the conical inner wall surface and the through hole of the cylinder head and the front end surface of the screw head and the screw groove at the front end of the screw are the outer wall groove, the rear end surface of the torpedo, and the heating cylinder. And a gap between the seal portion and the conical inner wall surface of the cylinder head.

Further, a plurality of rear end grooves continuous with the plurality of outer wall grooves may be provided on the rear end face of the torpedo, or a heater may be embedded inside the torpedo.

At least one of the plurality of outer wall grooves of the torpedo is provided with an insertion hole penetrating from the outer wall surface of the cylinder head to the outer wall groove, and the temperature of the molten resin in the outer wall groove through the insertion hole. Or a thermocouple for detecting the tip is inserted so that the tip thereof reaches the outer wall groove, or penetrates the cylinder head from each outer wall groove to the outer wall surface of the cylinder head corresponding to each of the plurality of outer wall grooves of the torpedo. Provide communication holes, connect pipes with valves interposed in each communication hole, or provide a plurality of steps in the leading and trailing end surfaces of the torpedo, and form them on the outer wall surface of the torpedo It is effective to provide uneven portions on the inner surfaces of the plurality of outer wall grooves.

Further, the torpedo linear drive means for moving the torpedo forward and backward in the axial direction comprises a lever rotating around a pivot and a fluid pressure cylinder connected to one end of the lever via a rod, It is preferable that the other end of the lever is inserted into an engagement hole formed in an outer wall of the torpedo through an insertion hole provided in the cylinder head.

In addition, the screw head may be removably fixed to the screw, or the screw head may be attached to the screw in the axial direction but free to rotate.

[0026]

In the plasticizing process, when the torpedo is retracted, the seal portion of the torpedo is separated from the conical inner wall surface of the cylinder head, and the screw groove and the reservoir at the tip of the screw are formed in the torpedo. And a gap between the rear end face of the torpedo and the heating cylinder and a gap between the sealing portion and the conical inner wall surface of the cylinder head. Thereby, the molten resin flows to the reservoir side and is stored in the reservoir.

When the torpedo is advanced during the injection and pressure-holding step, the seal portion of the torpede abuts on the conical inner wall surface of the cylinder head, and the backflow of the molten resin from the reservoir side to the screw side is reliably prevented. Is done.

[0028]

Embodiments of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the screw type injection molding apparatus according to the present embodiment comprises a heating cylinder 1 having a cylinder head 4 fixed at its tip so as to be detachable by a plurality of fixing means such as bolts 17; Band heaters 18 provided on the outer wall surfaces of the cylinder head 4 and the heating cylinder 1, which are heating means for heating the cylinder head 4 and the heating cylinder 1, respectively, and a screw 2 disposed rotatably and axially movable in the heating cylinder 1. And a torpedo 7 having an injection nozzle 5 disposed at the tip of the cylinder head 4, and a cylindrical portion 4 b in the cylinder head 4 having a through hole 7 b penetrating in the axial direction.
Are provided so as to be slidable in the axial direction.
Inside the screw head 3 provided at the tip of the screw 2
Are slidably fitted in the circumferential direction and the axial direction.

In this embodiment, as shown in FIGS. 3 and 4, the torpedo 7 has a seal 7 provided at a portion surrounding the opening edge of the through hole 7b on the conical tip surface.
c, and a flow path forming surface 7a in which a gap is formed when the seal portion 7c abuts on the conical inner wall surface 4a of the cylinder head 4 is formed in an outer peripheral portion surrounding the seal portion 7c. Have been. A plurality of outer wall grooves 8a extending in the axial direction are formed on the outer wall surface of the torpedo 7 at intervals in the circumferential direction, and the tip side of each outer wall groove 8a is open to the flow path forming surface 7a. The rear end side is communicated with the screw groove 2a at the front end of the screw 2 by a rear end groove 8b provided on the conical rear end surface of the torpedo 7. Further, as shown in FIG. 6, an engagement hole 8c into which one end side of a lever 10 to be described later is inserted is formed at an appropriate portion in the outer wall surface of the torpedo 7 except for the outer wall groove 8a.

Here, an example of the torpedo linear drive means 16 used in this embodiment will be described.

As shown in FIGS. 1 and 2, the lever 10
A pivot 9 is attached to a support member 9 protruding from the cylinder head 4.
a one end of which is inserted into an engagement hole 8c of the torpedo 7,
The other end is connected via a pin 12 to a rod 15 which is extended and contracted by a fluid pressure cylinder 11 rotatably pivotally connected via a pin 13 to a bracket 14 fixed to the outer wall of the heating cylinder 1. For this reason, the fluid pressure cylinder 11
When the lever 10 is operated in the direction in which the rod 15 is protruded, the lever 10 rotates in the direction of the arrow shown in FIG. 1 and the torpedo 7 is retracted. Conversely, when the rod 15 is operated in the retracting direction, the lever 10 is moved in the direction of the arrow shown in FIG. And the torpedo 7 moves forward.

Since the moving distance of the torpedo 7 by forward or backward movement is about 0.3 mm to 2 mm, the size of the fluid pressure cylinder 11 may be small.

Next, the operation of this embodiment will be described.

In the plasticizing step, as shown in FIG. 1, the hydraulic cylinder 11 is operated in the direction in which the rod 15 is protruded, the lever 10 is rotated in the direction of the arrow, and the torpedo 7 is retracted. By separating the seal portion 7c at the front end surface from the conical inner wall surface 4a of the cylinder head 4, the screw groove 2a and the reservoir 6 are communicated with each other via the rear end groove 8b, the outer wall groove 8a and the gap S, The screw 2 is rotated.

Then, when a resin is charged from a hopper (not shown), the charged resin is kneaded and melted while being transferred forward by the rotating screw 2 and is sequentially melted in the rear end groove 8.
b, the screw 2 is stored in the reservoir 6 through the outer wall groove 8a and the gap S, and retreats while rotating by the resin pressure with the increase of the molten resin stored in the reservoir 6,
When the amount of the molten resin stored in the reservoir 6 reaches a predetermined amount, the screw 2 is stopped.

At this time, at the same time as the screw 2 stops, the fluid pressure cylinder 11 is actuated in the direction of pulling in the rod 15 and the lever 10 is turned in the direction of the arrow to advance the torpedo 7, and the torpedo 7 The sealing portion 7c is formed as a conical inner wall surface 4a of the cylinder head 4.
Contact. That is, the resin flow path is closed. As a result,
Simultaneously with the end of the plasticizing step, the flow path of the molten resin stored in the reservoir 6 toward the outer wall groove 8a and the screw groove 2a is closed. In this case, since the molten resin does not flow toward the reservoir 6 from the screw groove 2a until the injection / pressure-holding step is started, the resin density in the reservoir 6 immediately before the injection / pressure-holding step is started. Stability is maintained.
In the injection and pressure-holding step, as shown in FIG. 2, the screw 2 is advanced and the reservoir 2 is advanced in a state where the sealing portion 7 c at the tip end surface of the torpedo 7 and the conical inner wall surface 4 a of the cylinder head 4 are in contact with each other. The molten resin stored in 6 is injection-filled into the cavity of a mold (not shown) that has been clamped through the injection nozzle 5.

In this case, since the resin flow path is closed as described above, backflow of the molten resin from the reservoir 6 to the screw 2 is reliably prevented.

Next, a description will be given of an operation in the case where plasticization is performed such that the relative position between the rear end groove 8b of the torpedo 7 and the screw groove 2a at the front end of the screw 2 becomes constant in the plasticizing step.

FIG. 5A shows a state at the time of completion of the injection / pressure-holding step.
First, by rotating the lever 10 in the direction of the arrow as shown in FIG. 5B to retract the torpedo 7, the seal portion 7c of the torpedo 7 is separated from the conical inner wall surface 4a of the cylinder head 4. The resin flow path is opened, and the screw 2 is retracted to a predetermined position.

After the above process, the process proceeds to the plasticizing process. As shown in FIG. 5C, the screw 2 rotates in the axial direction while stopped at the predetermined position, and the rotating screw is rotated. The melted resin kneaded and melted by the step 2 is sequentially filled with the rear end groove 8b, the outer wall groove 8a and the gap S of the torpedo 7.
And is stored in the reservoir 6. When the amount of the molten resin stored in the reservoir 6 reaches a predetermined amount, the torpedo 7 is advanced by rotating the lever 10 in the direction of the arrow as shown in FIG. After contacting the conical inner wall surface 4a of the cylinder head 4,
Stop screw 2 rotation.

Next, in the state shown in FIG. 5D, the screw 2 is advanced, so that the reservoir 6 is inserted into the cavity of the clamped mold (not shown) via the injection nozzle 5.
The molten resin stored in the container is injected and filled.

In the above embodiment, the rear groove 8b is formed in the torpedo 7, but when the torpedo 7 is retracted, a gap is formed between the rear end face and the front end face of the heating cylinder 1. 7, the rear end groove 8b is not necessarily formed.

Next, a description will be given of a modified example. The same reference numerals are given to portions which may be the same as those in the above-described embodiment, and description thereof will be omitted. Only different portions will be described.

It should be noted that each of the modifications is not an alternative to the above-described embodiment, and other modifications may be combined in accordance with the purpose of use.

(First Modification) In this modification, as shown in FIG. 7, a plurality of protrusions 40 are provided on the inner wall surface of the cylinder head 4 so as to engage with the outer wall grooves 8a of the torpedo 7, and the cylinder head of the torpedo 7 is provided. 4 is more strongly prevented from rotating.

(Second Modification) In this modification, as shown in FIG. 8, a portion of the cylinder head 4 corresponding to each outer wall groove 8a of the torpedo 7 is moved from the outer wall surface of the cylinder head 4 to each outer wall groove 8a. A through hole 50 is provided, and a pipe 52 having a valve 51 interposed therebetween is connected to each of the communication holes 50.

According to this modification, the foaming gas or additive is injected into the molten resin flowing in each outer wall groove 8a by connecting a foaming gas supply source or an additive supply source (not shown) to each pipe 52. can do. Also, the pipe 52
When a vacuum generating source (not shown) is connected to the vacuum cleaner, deaeration by vacuum suction can be easily performed sequentially through the outer wall groove 8a and the communication hole 50.

(Third Modification) In this modification, as shown in FIG. 9, a portion of the cylinder head 4 corresponding to each outer wall groove 8a of the torpedo 7 is moved from the outer wall surface of the cylinder head 4 to each outer wall groove 8a. Insertion holes 60 that penetrate the thermocouple 6
A plurality of heaters 63 are inserted into the torpedo 7 at intervals in the circumferential direction, and the heaters 63 are buried in the torpedo 7.

In this modification, the temperature of the molten resin in each outer wall groove 8a is detected by each thermocouple 61 and each heater 6
By controlling the heating temperature of No. 3 to a predetermined temperature, it is possible to more precisely control the molten resin temperature.

The number of the thermocouples 61 can be changed as required, and the number of the insertion holes 60 can be changed.
It can be changed to a number corresponding to the number of 1.

(Fourth Modification) In this modification, as shown in FIG. 10, instead of providing the rear end groove 8b on the rear end face of the torpedo 7 in the above embodiment, the outer diameter is gradually increased from the rear end side. In addition to providing a plurality of stepped portions 71 that expand, a saw-toothed uneven portion 70 is provided on the inner surface of the outer wall groove 8a, and the outer diameter is gradually increased stepwise from the rear end to the outer wall surface of the seal portion 7c at the front end surface. A plurality of steps 71 are provided in a step-like manner.

In the present embodiment, the molten resin passing through these portions is more strongly kneaded by the step portions 71 and the uneven portions 70, and is stored in the reservoir 6.

In the present invention, there is a modified example described below as a screw head detachably attached to the tip of the screw.

In this modification, as shown in FIG. 11, a male screw portion 23 provided on the front end surface of the screw 22 and provided on a small diameter portion on the rear end side of the screw head 23 on the screw portion 22a.
b to screw the screw head 23 into the screw 2
It is detachably attached to the tip of the second. In this modification, the screw head 23 rotates integrally with the screw 22.

In the modification shown in FIG. 12, the male screw portion 35b of the shaft member 35 having a small-diameter male screw portion 35b on the rear side is screwed and attached to the screw portion 32a provided on the tip end surface of the screw 32. In addition, the screw portion is screwed into the male screw portion of the stopper 34 fitted in the annular concave portion 35a formed in the screw side portion of the shaft member 35 because the screw portion is formed on the opening side of the coupling hole 33c of the screw head 33. By doing so, it is freely rotatable with respect to the screw head 33.

As a result, the screw head 33 linearly moves integrally with the screw 32 in the axial direction.
2 can rotate freely, and the frictional force between the inner wall surface of the torpedo 7 and the outer wall surface of the screw head does not rotate during the rotation of the screw 32. Therefore, the outer wall surface of the screw head and the inner wall surface of the torpedo 7 There is no danger of wear and the durability is improved.

[0058]

Since the present invention is configured as described above, the following effects can be obtained.

As in the above-described conventional in-line screw type injection molding apparatus provided with a backflow prevention ring, backflow of the molten resin from the reservoir to the screw groove at the start of the injection and pressure-holding step from the plasticizing step may occur. In addition, during the plasticization process, since the molten resin flows into the reservoir as a thin layer only through the outer wall groove formed on the outer wall surface of the torpedo, the state of the molten resin passing through the outer wall groove is precisely controlled. And the state of the molten resin stored in the reservoir becomes uniform. further,
Since the molten resin does not flow from the screw groove toward the reservoir between the time when the plasticization process is completed and the time when the injection / pressure holding process is started, the inside of the reservoir immediately before the injection / pressure holding process starts. Resin density is stabilized. As a result, the quality of the molded product is stabilized.

When the cylinder head and the screw head are made detachable, the cylinder head and the screw head can be replaced and the torpedo can be replaced. Therefore, the cylinder head and the screw head or the torpedo can be replaced according to the purpose of use. By doing so, various product functions can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic partial cross-sectional view of a main part during a plasticizing step, showing an embodiment of a screw-type injection molding apparatus according to the present invention.

FIG. 2 is a schematic partial cross-sectional view of a main part of the screw injection molding apparatus shown in FIG. 1 during an injection / holding process.

FIG. 3 is a plan view showing an example of a torpedo in a screw-type injection molding apparatus according to the present invention.

4A is a side view of the torpedo shown in FIG. 3 as viewed from an arrow A side in FIG. 3, FIG. 4B is a side view as viewed from an arrow B side in FIG. 3, and FIG. It is sectional drawing which follows the CC line of FIG.

FIG. 5 shows a screw type injection molding apparatus shown in FIG.
It is explanatory drawing in the case of performing a plasticization process, without changing the relative position of a screw groove and the back end groove of a torpedo.

FIG. 6 is a schematic partial sectional view of a torpedo and a cylinder head in the embodiment shown in FIG. 1;

FIG. 7 is a schematic partial sectional view of a first modified example of a torpedo and a cylinder head according to the present invention.

FIG. 8 is a schematic partial sectional view of a second modification of the torpedo and the cylinder head in the present invention.

FIG. 9 is a schematic partial sectional view of a third modification of the torpedo and the cylinder head in the present invention.

10A and 10B show a fourth modification of the torpedo according to the present invention, wherein FIG. 10A is a schematic plan view, and FIG. 10B is a side view as viewed from the direction of arrow A in FIG.

FIG. 11 is a schematic partial sectional view showing a modified example of a joint portion between a screw head and a screw in the present invention.

FIG. 12 is a schematic partial cross-sectional view showing another modified example of the joint portion between the screw head and the screw according to the present invention.

13A and 13B show a conventional in-line screw type injection molding apparatus provided with a backflow prevention ring, where FIG. 13A is a schematic partial cross-sectional view of a main part in a plasticizing step, and FIG. FIG. 4 is a schematic partial sectional view of a part.

14A and 14B show a conventional conical screw type injection molding apparatus, wherein FIG. 14A is a schematic partial cross-sectional view of a main part during a plasticizing step, and FIG. 14B is a schematic partial cross-sectional view of a main part during an injection step.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating cylinder 2, 22, 32 Screw 2a Screw groove 3, 23, 33 Screw head 4 Cylinder head 4a Conical inner wall surface 4b Tubular part 4c Bolt hole 5 Injection nozzle 6 Reservoir 7 Torpedo 7a Flow path forming surface 7b Penetration Hole 7c Seal portion 8a Outer wall groove 8b Rear end groove 8c Engagement hole 9 Support member 9a Axis 10 Lever 11 Fluid pressure cylinder 12 Pin 15 Rod 16 Linear drive means for torpedo 17 Bolt 18 Band heater 34 Clasp 35 Shaft member 35a Annular recess REFERENCE SIGNS LIST 40 Projecting portion 50 Communication hole 51 Valve 52 Pipeline 60 Insertion hole 61 Thermocouple 62 Holder 63 Heater 70 Uneven portion 71 Step portion

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-223238 (JP, A) JP-A-2-143817 (JP, A) JP-A-62-117715 (JP, A) JP-A-62-117715 83118 (JP, A) JP-A-58-224732 (JP, A) JP-A-53-106765 (JP, A) JP-A-49-28654 (JP, A) Japanese Utility Model Laid-Open No. 61-164719 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 45/52 B29C 45/63 B29C 45/76

Claims (9)

(57) [Claims] 1. A heating cylinder (1) having a cylinder head (4) detachably fixed to a tip end thereof; and heating means for heating the cylinder head (4) and the heating cylinder (1), respectively; A screw (2) having a screw head (3) at a tip end thereof rotatably disposed in the heating cylinder (1) and capable of moving back and forth in the axial direction, and slidably disposed in the cylinder head (4). A torpedo (7) provided and a torpedo linear drive means (16) for moving the torpedo (7) in the axial direction, wherein the torpedo (7) comprises the torpedo (7); A through hole (7b) penetrating in the axial direction into which the screw head (3) is slidably inserted in the circumferential direction and the axial direction, and a portion surrounding a periphery of an opening of the through hole (7b) at the tip end surface. In a seal portion provided (7c), extending the outer wall grooves into a plurality of axially formed at intervals in the circumferential direction on the outer wall surface (8
a) when the torpedo (7) is retracted and the seal portion (7c) is separated from the conical inner wall surface (4a) of the cylinder head (4). The reservoir (6) formed by the conical inner wall surface (4a) and the through hole (7b) and the distal end surface of the screw head (3) and the screw groove (2a) at the distal end of the screw (2). Are formed between the outer wall groove (8a), the gap between the rear end surface of the torpedo (7) and the heating cylinder (1), and the gap between the sealing portion (7c) and the conical inner wall surface (4a) of the cylinder head (4). A screw-type injection molding device characterized by being communicated by a gap. 2. A plurality of rear end grooves (8b) continuous with a plurality of outer wall grooves (8a) on a rear end surface of the torpedo (7).
The screw-type injection molding apparatus according to claim 1, further comprising: 3. A heater (6) inside a torpedo (7).
3. The screw-type injection molding apparatus according to claim 1, wherein 3) is embedded. 4. A plurality of outer wall grooves (8) of a torpedo (7).
a), an insertion hole (60) penetrating from the outer wall surface of the cylinder head (4) toward the outer wall groove (8a) is provided, and the outer wall groove (60) is inserted through the insertion hole (60). The tip of the thermocouple (61) for detecting the temperature of the molten resin in 8a) is connected to the outer wall groove (8a).
The screw-type injection molding apparatus according to any one of claims 1 to 3, wherein the screw-type injection molding apparatus is inserted so as to reach the inside. 5. A plurality of outer wall grooves (8) of a torpedo (7).
Corresponding to (a), the cylinder head (4) is provided with a communication hole (50) penetrating from each outer wall groove (8a) to the outer wall surface of the cylinder head (4).
A pipe (52) having a valve (51) interposed therebetween is connected to each of the pipes.
The screw-type injection molding apparatus according to the above item. 6. A torpedo (7) having a plurality of steps (71) provided in a stepped manner on a front end surface and a rear end surface thereof, and a plurality of outer wall grooves (8) formed on an outer wall surface of the torpedo (7).
The screw-type injection molding apparatus according to any one of claims 1 to 5, wherein an uneven portion (70) is provided on the inner surface of (a). 7. A torpedo linear drive means (16) for moving the torpedo (7) back and forth in the axial direction includes a pivot (9).
a) a lever (10) that rotates about a fulcrum, and a fluid pressure cylinder (11) connected to one end of the lever (10) via a rod (15).
7. The other end of the torpedo (0) is inserted into an engagement hole (8c) formed in an outer wall of the torpedo (7) through an insertion hole provided in the cylinder head (4). The screw injection molding apparatus according to claim 1. 8. The screw head (23) is connected to the screw (2).
The screw-type injection molding apparatus according to any one of claims 1 to 7, wherein the screw-type injection molding apparatus is detachably fixed to (2). 9. The screw head (33) is connected to the screw (3).
9. The screw-type injection molding apparatus according to claim 1, wherein the screw-type injection molding apparatus is integrated in the axial direction but is freely rotatable.