JP3236823B2 - Injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an injection molding machine.

[0002]

2. Description of the Related Art Conventionally, in an injection molding machine, a resin heated and melted in a heating cylinder is injected at a high pressure to fill a cavity space of a mold apparatus.
A molded product can be obtained by cooling and solidifying in the cavity space.

The injection molding machine has a mold clamping device and an injection device. The mold clamping device has a fixed platen and a movable platen, and a mold closing cylinder advances and retreats the movable platen to close, close, and close the mold. Open the mold. On the other hand, the injection device includes a heating cylinder that heats and melts the resin supplied from the hopper, and an injection nozzle that injects the melted resin, wherein a screw is rotatable in the heating cylinder and moves forward and backward. Arranged freely. Then, the resin is injected from the injection nozzle by moving the screw forward, and the resin is measured by moving the screw backward.

FIG. 2 is a sectional view of a conventional injection device. In the drawing, reference numeral 111 denotes a driving unit case surrounding a driving unit (not shown). The driving unit case 111 includes a front cover 113, a center case 115, and a rear cover 117.
A heating cylinder 112 is fixed to a front end (left end in the figure) of the front cover 113, and a screw 122 is disposed in the heating cylinder 112 so as to be able to advance and retreat.

A metering motor 144 is provided on the front part (left part in the figure) of the drive part case 111, and an injection motor 145 is provided on the same part axis on the rear part (right part in the figure). Is done. The metering motor 144 includes a stator 146 and an annular rotor 147 disposed on the inner peripheral side of the stator 146.
Is composed of a stator 148 and an annular rotor 149 disposed on the inner peripheral side of the stator 148.

[0006] The rotor 147 includes a drive unit case 111.
Is rotatably supported with respect to. Therefore, rotor 1
47 is fitted with a hollow first rotor shaft 156 (can)
It is inserted and fixed. On the other hand, the rotor 149 is also rotatably supported by the drive unit case 111. For this purpose, a hollow second rotor shaft 157 is attached to the rotor 149.
Is fitted and fixed.

By supplying a current to the stator 146 of the metering motor 144, the screw 122 can be rotated backward while rotating. To this end, a first spline nut 162 is fixed to the first rotor shaft 156, the first spline nut 162 and the first spline shaft 163 are spline-engaged, and the first spline shaft 163 and the screw 122 Are linked.

Further, a second spline nut 176 is fixed to the center case 115, the second spline nut 176 and the second spline shaft 171 are spline-engaged, and the first spline shaft 163 is
The spline shaft 171 is connected via a bearing box 172 so as to be relatively rotatable. On the other hand, in the injection motor 145, by supplying a current to the stator 148, the screw 122 can be advanced without rotating. For this purpose, an annular bearing retainer 164 is fixed to the rear end (right end in the drawing) of the second rotor shaft 157, and a ball screw shaft 165 is fitted and fixed to the inner periphery of the bearing retainer 164. The ball screw shaft 165 is rotatably supported by the drive unit case 111.

A ball nut 169 is provided in the second rotor shaft 157 so as to advance and retreat, and the ball nut 169 and the ball screw shaft 165 are screwed together, and the ball nut 169 and the second spline Axis 17
1 are connected. By the way, the weighing motor 144
Is a sleeve-shaped stator frame 201, and the injection motor 145 is a sleeve-shaped stator frame 202.
The front cover 113 and the center case 115 are connected by a threaded rod 203 across the stator frame 201, and the center case 115 and the rear cover 117 are
2 are connected by a threaded rod 204. Then, the stator frame 202 is
Are supported in the rotational direction by the frictional force generated by the tightening.

[0010]

However, in the conventional injection molding machine, the injection motor 145 is driven, the ball screw shaft 165 is rotated, and the screw 1 is rotated.
22 is advanced to inject the resin in the heating cylinder 112, the reaction force against the injection power
And transmitted to the rod 203 via the front cover 113 and the rod 20 via the rear cover 117.
4, the rods 203 and 204 are elongated and the tightening force is weakened.

In this state, as the metering motor 144 and the injection motor 145 are driven, the rotors 147 and 149 are driven.
When rotation occurs, the stator frames 201 and 202
May rotate, so that the tightening force of the rods 203 and 204 needs to be strictly controlled. As a result, assembly, maintenance, and management of the injection molding machine become cumbersome.

An object of the present invention is to solve the problems of the conventional injection molding machine and to provide an injection molding machine that can be easily assembled and maintained / managed.

[0013]

For this purpose, in an injection molding machine according to the present invention, there is provided a hollow motor having a stator and a rotor, a stator frame provided surrounding the hollow motor and supporting the stator. A front cover and a rear cover detachably connected to both ends of the stator frame, and are operated with the driving of the hollow motor;
A movement direction changing means for generating tension on the stator frame via the rear cover.

In another injection molding machine of the present invention, when the hollow motor is driven to inject the resin in the heating cylinder, the reaction force generated with respect to the ejection power is generated by the heating cylinder and the front cylinder. The tension is transmitted to the stator frame and the rear cover via the cover. In still another injection molding machine of the present invention, the stator frame further includes a tubular portion for supporting a stator,
And flange portions formed at both ends of the cylindrical portion.
In still another injection molding machine of the present invention, a weighing motor comprising a hollow motor having a stator and a rotor, and a hollow motor having a stator and a rotor disposed on the same axis as the weighing motor. An injection motor, a front frame surrounding the metering motor and supporting the stator, a rear frame surrounding the injection motor and supporting the stator, and a front end of the front frame. , A center frame disposed between the rear end of the front frame and the front end of the rear frame, and a rear cover disposed at the rear end of the rear frame. Then, the front cover and the front frame, the front frame and the center frame, the center frame and the rear frame, and the rear frame and the rear cover are fixed by bolts, respectively.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory diagram of a driving unit case of an injection device according to an embodiment of the present invention,
FIG. 3 is a first view showing an injection device according to the embodiment of the present invention.
FIG. 4 is a second sectional view showing the injection device according to the embodiment of the present invention, and FIG. 5 is a side view of the front frame according to the embodiment of the present invention. Note that FIG.
It is XX sectional drawing of.

In FIG. 3, reference numeral 12 denotes a heating cylinder. The heating cylinder 12 has an injection nozzle 12a at a front end (left end in the figure). A screw 22 is disposed in the heating cylinder 12 so as to be rotatable and advance / retreat. The screw 22 has a screw head 22a at the front end, extends rearward (to the right in the figure) inside the heating cylinder 12, and has a rear end (right end in the figure).
Is connected to a driving unit described later. A spiral flight 23 is formed around the screw 22, and the flight 23 forms a groove 26.

A resin supply port 29 is formed at a set position of the heating cylinder 12, and the resin supply port 2 is formed.
The hopper 30 is fixed to 9. The resin supply port 29 is
When the screw 22 is located at the most forward position (left side in the drawing) in the heating cylinder 12, it is formed at a position corresponding to the rear end (right end in the drawing) of the groove 26.

Therefore, in the measuring step, when the driving unit is driven to retract (move to the right in the drawing) while rotating the screw 22, the pellet-shaped resin 33 in the hopper 30 falls and falls. It enters the heating cylinder 12 and moves forward (moves to the left in the figure) in the groove 26. A heater (not shown) is provided around the heating cylinder 12 so that the heating cylinder 12 can be heated by the heater and the resin 33 in the groove 26 can be melted. Therefore, when the screw 22 is rotated backward by a predetermined amount, one shot of the melted resin 33 is stored in front of the screw head 22a.

Next, in the injection step, when the driving section is driven to advance without rotating the screw 22, the resin 33 stored in front of the screw head 22a is injected from the injection nozzle 12a. It is filled in a cavity space of a mold device (not shown). Next, the driving unit will be described.

1 and 4, reference numeral 11 denotes a drive unit case as a case surrounding the drive unit. The drive unit case 11 is fixed to the rear end of the heating cylinder 12 (FIG. 3). The drive unit case 11 includes a front cover 13, a center frame 15, a rear cover 17, a front frame 41 connecting the front cover 13 and the center frame 15, and a center frame 15 and the rear cover 1.
7 is connected to the rear frame 42. in this case,
The front frame 41 and the rear frame 42 constitute a stator frame, and the front cover 1
3. The center frame 15 and the rear frame 17 form an apparatus frame, and the front frame 41 and the rear frame 42 also function as the apparatus frame. The front cover 13 and the front frame 41 are connected to each other by the bolt b1.
And the center frame 15 by the bolt b2, the center frame 15 and the rear frame 42 by the bolt b3, and the rear frame 42 and the rear cover 17 by the bolt b4.
Are detachably connected to each other. It should be noted that the front cover 13 constitutes a first plate and the center frame 15 constitutes a second plate with respect to the front frame 41.
Represents a first plate, and the rear cover 17 constitutes a second plate.

Therefore, by removing the bolt b1, the front cover 13 and the front frame 41 are removed, and by removing the bolt b2, the front frame 41 and the center frame 15 are connected to the bolt b.
3, the center frame 15 and the rear frame 42 are separated from each other, and the bolt b4 is removed to separate the rear frame 42 and the rear cover 17 from each other.
The metering motor 44 or the injection motor 45 can be replaced. As a result, assembly, maintenance and management of the injection molding machine can be easily performed.

A metering motor 4 as a hollow motor is provided at a front portion (left portion in the figure) of the drive portion case 11.
Reference numeral 4 denotes an injection motor 45 as a hollow motor disposed on the same axis at the rear part (right part in the figure).
The metering motor 44 includes a stator 46 supported by the front frame 41, and an annular rotor 47 disposed on the inner peripheral side of the stator 46. An injection motor 45 is supported by the rear frame 42. And an annular rotor 49 disposed on the inner peripheral side of the stator 48.

The rotor 47 is rotatably supported by the drive case 11. For this purpose, a hollow first rotor shaft 56 is fitted and fixed to the rotor 47, and the front end (left end in the figure) of the first rotor shaft 56 is supported by the bearing 51 on the front frame 41.
The rear end of the center frame 15
Supported by

On the other hand, the rotor 49 is also provided in the drive case 1.
1 is supported rotatably. For this purpose, a hollow second rotor shaft 57 is fitted and fixed to the rotor 49, and the front end of the second rotor shaft 57 is supported by the bearing 53 on the center frame 15, and the rear end of the second rotor shaft 57 is supported on the rear frame 42 by the bearing 54. Is done. By the way, in the measuring motor 44, by supplying a current of a predetermined frequency to the stator 46, the screw 22 can be moved backward while rotating. To this end, the sleeve 18 is disposed on the inner periphery of the front part of the first rotor shaft 56, and the front end of the sleeve 18 and the front end of the first rotor shaft 56 are fixed by bolts b5. A first spline nut 62 is fixed to the rear end of the sleeve 18 by a bolt b12, and the first spline nut 62 and the first spline shaft 63 are spline-connected.
The screw 22 is fixed to the front end of the screw. in this case,
The first spline nut 62 and the first spline shaft 63
Thus, the first driving force transmitting means is constituted, the relative movement in the rotational direction is restricted, and the relative movement in the axial direction is allowed. The first spline shaft 63 has a length corresponding to the stroke of the screw 22.

Therefore, when the metering motor 44 is driven to rotate the rotor 47, the rotation of the rotor 47 becomes
The power is transmitted to the screw 22 via the first rotor shaft 56, the sleeve 18, the first spline nut 62, and the first spline shaft 63, and the screw 22 is rotated. Then, the resin 33 advances in the groove 26 while being melted, and the screw 22 is moved backward by the back pressure generated as the resin 33 advances.

At this time, since the first spline nut 62 and the first spline shaft 63 are spline-connected, the first spline shaft 63 is retracted relatively to the first spline nut 62. On the other hand, in the injection motor 45, by supplying a current of a predetermined frequency to the stator 48, the screw 22 can be advanced without rotating. To this end, an annular bearing retainer 64 is fixed to the rear end of the second rotor shaft 57, and the first shaft portion 65 a of the ball screw shaft 65 is fitted and fixed to the inner periphery of the bearing retainer 64. The ball screw shaft 65 is rotatably supported by the drive unit case 11. That is, the ball screw shaft 65 is supported on the rear cover 17 by the bearing 66 and the thrust bearing 68 via the bearing retainer 64. And the rear cover 1
7, a rear cap 77 via an annular load cell 75.
Are fixed via bolts b6, and the ball screw shaft 65 is
Is supported by a bearing 67 with respect to a rear cap 77. The absolute value pulse encoder 8 is connected to the rear cap 77 via a bracket 86.
5 are provided. The absolute value pulse encoder 85 is connected to the second shaft portion 65b and functions as a first rotation speed detection unit. The absolute value pulse encoder 85 detects the rotation speed of the ball screw shaft 65, that is, the rotation speed of the injection motor. It functions as a position detecting means, and detects the position of the screw 22 based on the rotation speed of the injection motor.

A ball nut 69 is provided in the second rotor shaft 57 so as to be able to advance and retreat, and the ball nut 69 and the ball screw shaft 65 are screwed together to constitute a movement direction changing means. Therefore, the rotation of the rotor 49 is transmitted to the ball screw shaft 65 via the second rotor shaft 57 and the bearing retainer 64, and the rotational motion is converted into a linear motion, and the ball nut 69 moves forward and backward. In order to prevent the ball screw shaft 65 from falling out of the ball nut 69, the ball screw shaft 6
The stopper 19 is fixed to the front end of the bolt 5 by a bolt b13.

In order to prevent the ball nut 69 from rotating together with the ball screw shaft 65, a sleeve-shaped second spline shaft 71 is fixed to the front end of the ball nut 69 by a bolt b11.
The second spline nut 76 fixed to 5 and the second spline shaft 71 are spline-connected. In this case, the second
The spline nut 76 and the second spline shaft 71 constitute a second driving force transmitting means, and the relative movement in the rotation direction is restricted, and the relative movement in the axial direction is allowed. The second spline shaft 71 has a length corresponding to the stroke of the screw 22.

A bearing box 7 as a third driving force transmitting means is provided at the front end of the second spline shaft 71.
2 are fixed by bolts b7, and a thrust bearing 73 is provided forward (to the left in the drawing) and a bearing 74 is provided rearward (to the right in the drawing) in the bearing box 72.
Is arranged. In this case, the bearing box 72
Constrain relative movement in the axial direction and allow relative movement in the rotational direction. Therefore, the first spline shaft 63 is rotatably supported by the thrust bearing 73 and the bearing 74 with respect to the second spline shaft 71 and the ball nut 69.

Further, a rear end shaft 22b of the screw 22 is connected to a front end of the first spline shaft 63 via a first coupling 81 and a second coupling 82.
8, fixed by b9. The first coupling 8
1 is the sleeve 18 as the screw 22 advances and retreats.
The inside can be moved. At the rear end of the first spline shaft 63, a concave portion 63a is formed at the retreat limit position of the first spline shaft 63 so as not to interfere with the head of the bolt b13. Therefore, the axial dimension of the injection molding machine can be reduced.

An encoder 84 is connected to the sleeve 18 through a gear train 87.
Functions as a second rotational speed detecting means, and the sleeve 18
, Ie, the rotation speed of the metering motor.
Reference numeral 89 denotes a water-cooled jacket, which is fixed to the front cover 13 by bolts b10, and is connected to the front cover 1 from the rear end of the heating cylinder 12.
3 to prevent heat from being transmitted.

Next, the operation of the driving section having the above configuration will be described. First, in the injection step, when a current is supplied to the stator 48 of the injection motor 45, the rotor 49 is rotated, and the rotation of the rotor 49 is controlled by the second rotor shaft 5.
7 and the ball screw shaft 6 via the bearing retainer 64
5 and the ball screw shaft 65 is rotated.
At this time, since the second spline nut 76 fixed to the center frame 15 and the second spline shaft 71 are spline-connected, the ball nut 69 does not rotate. Therefore, a thrust is generated in the ball nut 69, and the ball nut 69 is advanced.

During this time, the metering motor 44 is not driven, and the rotor 47 is stopped. Therefore, the first spline shaft 63 disposed in front of the ball nut 69
Is advanced without rotating, the screw 2
Advance 2 In this manner, the rotational motion generated by the injection motor 45 is converted into a linear motion by the ball screw shaft 65 and the ball nut 69. As a result, the resin 3 stored in front of the screw 22
3 can be injected from the injection nozzle 12a.

Next, in the measuring step, the measuring motor 4
When the current is supplied to the stator 46 of No. 4, the rotor 47 is rotated, and the rotation of the rotor 47 is transmitted to the first spline shaft 63 via the first rotor shaft 56, the sleeve 18, and the first spline nut 62, The first spline shaft 63 is rotated. Then, the rotation of the first spline shaft 63 is transmitted to the screw 22, and the screw 22 is rotated. Accordingly, the groove 2
6, the resin 33 moves forward while being melted.
The screw 22 is caused to retreat by a back pressure generated with the advance of the screw.

At this time, since the first spline nut 62 and the first spline shaft 63 are spline-connected, the first spline shaft 63 is relatively retracted with respect to the first spline nut 62. The injection motor 45 is driven while controlling the back pressure of the resin 33 to be measured, and the rotor 49 is rotated in a direction to retract the screw 22. At this time, the load applied in the axial direction of the screw 22 or the like is detected by the load meter 75,
The back pressure can be calculated based on the load. Alternatively, a pressure sensor (not shown) may be provided in the heating cylinder 12, the pressure sensor detects the pressure of the resin 33 in the heating cylinder 12, and the back pressure can be calculated based on the pressure.

By the way, the front frame 41 is
The cylindrical portion 208 supporting the stator 46 and the cylindrical portion 2
08 at both ends of a square flange 2 integrally formed
21 and the flange portion 221 has four corner portions 2
With 10. A hole 209 is formed in the corner portion 210 to allow the bolts b1 and b2 to pass therethrough.

In order to position the front frame 41 with respect to the front cover 13, a circular step f 1 is formed in the front cover 13, and in order to position the front frame 41 with respect to the center frame 15, a center is formed. A circular step f2 is formed in the frame 15. The rear frame 42 includes a stator 48
And a quadrangular flange 222 integrally formed at both ends of the cylindrical portion 218. The flange 222 has four corners 220. Then, bolts b3, b4
Hole 219 for penetrating through is formed.

In order to position the rear frame 42 with respect to the center frame 15, a circular step f3 is formed in the center frame 15,
A circular step f4 is formed on the rear cover 17 in order to position the rear frame 42 with respect to the rear frame 42. As described above, the front cover 13 is provided by the front frame 41.
And the center frame 15 is connected to the center frame 15 and the rear cover 17 by the rear frame 42, and the front frame 41 and the rear frame 42 include cylindrical portions 208 and 218 and flange portions 221 and 222. When the resin 45 in the heating cylinder 12 is injected by rotating the ball screw shaft 65 and advancing the screw 22 by injecting the resin in the heating cylinder 12, the reaction force with respect to the ejection power is transmitted through the heating cylinder 12 and the front cover 13. Even if tension is transmitted to the front frame 41 and to the rear frame 42 via the rear cover 17, the front frame 41 and the rear frame 42 do not extend. Therefore, the tightening force of the bolts b1 to b4 does not decrease.

The front cover 13 and the front frame 41 are connected to each other by the bolts b1.
1 and the center frame 15 by the bolt b2, the center frame 15 and the rear frame 42 by the bolt b3, and the rear frame 42 and the rear cover 17 by the bolt b2.
4, so that even if the tightening force of the bolts b1 to b4 is weakened, the measuring motor 4
The front frame 41 and the rear frame 42 do not rotate with the driving of the motor 4 and the injection motor 45.

Therefore, since it is not necessary to strictly control the tightening force of the bolts b1 to b4, assembly, maintenance and management of the injection molding machine can be easily performed. It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0041]

As described in detail above, according to the present invention, in an injection molding machine, a hollow motor having a stator and a rotor, and a hollow motor are provided so as to surround the hollow motor.
A stator frame supporting the stator, a front cover and a rear cover detachably connected to both ends of the stator frame, and actuated in accordance with driving of the hollow motor to generate tension in the stator frame via the rear cover; Movement direction changing means for causing the movement direction to be changed.

In this case, the hollow motor can be replaced by separating the stator frame from the front cover and the rear cover. Further, since the stator frame is connected to the front cover and the rear cover, the stator frame does not rotate when the hollow motor is driven. Therefore, it is not necessary to strictly control the tightening force for connecting the stator frame to the front cover and the rear cover. As a result, assembly, maintenance and management of the injection molding machine can be easily performed.

According to another injection molding machine of the present invention, there is provided a metering motor comprising a hollow motor having a stator and a rotor, and a hollow motor provided on the same axis as the injection motor and having a stator and a rotor. An injection motor comprising: a front frame that surrounds the metering motor and supports a stator; a rear frame that surrounds the injection motor and supports a stator; and the front frame , A front cover disposed at a front end of the front frame, a center frame disposed between a rear end of the front frame and a front end of the rear frame, and a rear cover disposed at a rear end of the rear frame. And
The front cover and the front frame, the front frame and the center frame, the center frame and the rear frame, and the rear frame and the rear cover are fixed by bolts, respectively. In this case, the front cover and the front frame, the front frame and the center frame, the center frame and the rear frame,
Since the rear frame and the rear cover are fixed by bolts respectively, when the screw is advanced to inject the resin, the reaction force against the injection power is applied to the front frame via the front cover and the rear frame via the rear cover. , The front frame and the rear frame do not extend. Further, since the front frame and the rear frame do not rotate with the driving of the injection motor and the metering motor, it is not necessary to strictly control the bolt tightening force. Therefore, assembly, maintenance, and management of the injection molding machine can be easily performed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a driving unit case of an injection device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conventional injection device.

FIG. 3 is a first sectional view showing the injection device according to the embodiment of the present invention.

FIG. 4 is a second sectional view showing the injection device according to the embodiment of the present invention.

FIG. 5 is a side view of the front frame according to the embodiment of the present invention.

[Explanation of symbols]

 13 Front Cover 15 Center Frame 17 Rear Cover 41 Front Frame 42 Rear Frame 44 Metering Motor 45 Injection Motor 46, 48 Stator 47, 49 Rotor 208, 218 Tubular Part 221, 222 Flange Part

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 45/00-45/74

Claims (4)

(57) [Claims] (A) a hollow motor having a stator and a rotor; (b) a stator frame disposed to surround the hollow motor and supporting the stator; and (c) detachably attached to both ends of the stator frame. A front cover and a rear cover freely connected to each other ;
Tension is applied to the stator frame via the rear cover.
An injection molding machine comprising: a moving direction converting means for generating a moving direction . 2. A previous SL by driving the hollow motor heating cylinder
When the resin inside is injected,
Reaction force is generated via the heating cylinder and the front cover.
The injection molding machine according to claim 1, wherein the transmission is performed under tension to the stator frame and the rear cover . 3. The injection molding machine according to claim 1, wherein the stator frame includes a tubular portion for supporting the stator, and flange portions formed at both ends of the tubular portion. 4. A hollow having a stator and a rotor.
A weighing motor comprising a motor; and (b) a stator arranged on the same axis as the weighing motor .
Motor comprising a hollow motor having a rotor and a rotor
When it is disposed to surround the motor the metering (c), the stator
And (d) a stator disposed around the injection motor,
And (e) Freon provided at the front end of the front frame.
And Tokaba, (f) prior to the trailing edge and the rear frame of the front frame
A center frame disposed between the end, a rear cover disposed on the rear end of the (g) the rear frame
Together with the door, and the (h) the front cover and the front frame, off
The front frame and the center frame are the center frame
And the rear frame, and the rear frame and the rear cover
Injection characterized by being fixed by bolts respectively
Molding machine.