JP2002001774A - Equipment and method for gate cutting and ejection of injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct gate cutting and ejection by one driving equipment. SOLUTION: A first ball screw (13) and a second ball screw (15) of an injection molding machine (10) which drive a gate cutter pin (12) and an ejector pin (14) of a mold (30) respectively are disposed coaxially with each other and the first ball screw (13) and the second ball screw (15) are driven by one driving equipment (20, 24, 26). According to the direction of rotation of the driving equipment (20, 24, 26), the second ball screw (15) withdraws when the first ball screw (13) projects, and the second ball screw (15) projects when the first ball screw (13) withdraws.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for cutting and projecting a gate of an injection molding machine.

[0002]

2. Description of the Related Art FIG. 3 is a side sectional view of a gate cutting and projecting device of a conventional injection molding machine, and FIG. 4 is an enlarged view of a gate cut pin and an ejector pin.

In this example, a movable die 30a fixed to a movable plate 50 has a through hole 12a formed in an axial direction, and a gate cut pin 12 is disposed inside the through hole 12a. The gate cut pin 12 has a through hole 14a
Are formed, and an ejector pin 14 is arranged concentrically with the gate cut pin 12. Ejector pin 14
Is connected to the air cylinder 56 at the end of the first protruding member 55 capable of protruding the ejector pin 14, and when the first protruding member 55 protrudes due to the reciprocating motion of the air cylinder 56, the ejector pin 14 is moved. It protrudes and separates from the ejector pin 14 when the first protruding member 55 is retracted. The driving device side end 53b of the second projecting member 53 capable of projecting the gate cut pin 12 is provided with an air cylinder 5
6, two ball screws 58 are arranged in parallel and penetrate therethrough. A nut 60 connected to the drive device side end 53b is screwed into each of the ball screws 58. I have. Pulleys 62 are attached to the ends of the respective ball screws 58 so as to rotate together with them, and the respective pulleys 62 are attached to a single servo motor 64 so as to rotate in synchronization with each other.
6 are connected.

[0004] As shown in FIG. 4, the end of the gate cut pin 12 on the side of the second projecting member 53 is provided on the outer periphery of the ejector pin 14 concentrically therewith.
, And a large ring-shaped stopper 23 are arranged on the outer peripheral portion of the small ring-shaped stopper 21 concentrically therewith.
The small ring-shaped stopper 21 can be pushed by the second projecting member 53 to push the gate cut pin 12 in the projecting direction, and the large ring-shaped stopper 23 can
2 restricts further movement in the retracting direction than the neutral position constituting a part of the surface of the movable mold 30a. A first spring 17 is provided between the gate cut pin 12 and the movable mold 30a, a second spring 19 is provided between the gate cut pin 12 and the ejector pin 14, and between the ejector pin 14 and the small ring-shaped stopper 21. Are provided with third springs 25, respectively. The first spring 17 constantly urges the gate cut pin 12 in the retracting direction, and
The spring 19 and the third spring 25 are constantly urged in a contracting direction. In addition, the second spring 19 constantly urges the gate cut pin 12 in a protruding direction and always urges the ejector pin 14 in a retracting direction. Third spring 2
Numeral 5 always urges the ejector pin 14 in the protruding direction and always urges the ring-shaped stopper small 21 in the retracting direction.

Next, the operation of the prior art will be described.

As shown in FIG. 3 (a), the gate cut pin 12 and the ejector pin 14 constitute a part of the surface of the movable mold 30a from the time the mold 30 is closed until the cavity filling is completed. First to come in position
The protruding member 55 and the second protruding member 53 are located.

Next, at the time of gate cutting shown in FIG. 3B, the servo motor 64 is driven to synchronize the two pulleys 62 via the belt 66 and rotate them in a predetermined direction. As a result, the two ball screws 58 are integrally rotated with the respective pulleys 62, and are rotated in synchronization with each other.
Moves forward. For this reason, the second protrusion members 53 connected to the respective nuts 60 move in the protruding direction and hit the small ring-shaped stoppers 21, and the small ring-shaped stoppers 21.
Pushes the gate cut pin 12 in the protruding direction.
As a result, the gate cut pins 52 project to perform a gate cut operation.

Next, at the time of the ejector shown in FIG. 3C, the servo motor 64 is driven to synchronize the two pulleys 62 via the belt 66 and rotate them in the opposite direction. Thereby, each pulley 62 and 2
The two ball screws 58 are synchronized and rotate in the opposite direction to the above, and the respective nuts 60 are retracted and the second projecting members 5 are rotated.
3 moves in the retracting direction and separates from the ring-shaped stopper small 21. For this reason, the gate cut pin 12 is retracted by the pressing force of the first spring 17. Thereafter, the mold 30 is opened, the air cylinder 56 is driven, and the reciprocating movement of the air cylinder 56 moves the first projecting member 55 in the projecting direction to press the ejector pin 14 to eject the molded product.

Next, the air cylinder 56 is driven to move the first projecting member 55 in the retracting direction by reciprocating the air cylinder 56 to separate the ejector pin 14 from the ejector pin 14, and the ejector pin 14 is moved to the second spring 19 and the third spring 25. A series of gate cutting and ejecting operations are completed by locating the gate in the neutral position by the spring force.

[0010]

However, in the above-mentioned conventional gate cutting and projecting device, the two ball screws 58 arranged in parallel in order to project the gate cut pin 52 are synchronized and rotated. For this reason, the synchronization adjustment of the two ball screws 58 and the belt 6
When the synchronization is lost due to the elongation of 6, the ball screws 58 are likely to be damaged by receiving an uneven load.

Further, since the drive source is an electric drive source such as a servomotor at the time of gate cutting, and is a drive source by air such as an air cylinder at the time of an ejector, a plurality of drive sources must be provided, and the device structure becomes complicated. There is a problem.

The present invention is to solve such a problem.

[0013]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, a gate cut pin (12) and an ejector pin (14) of a mold (30) are provided. The first ball screw (13) and the second ball screw (15) of the injection molding machine (10) that respectively drive
The first ball screw (1
3) and the second ball screw (15) are connected to one drive device (2
0, 24, 26), and the driving device (20, 2,
When the first ball screw (13) protrudes according to the rotation direction of (4, 26), the second ball screw (15) retracts,
When the first ball screw (13) is retracted, the second ball screw (15) is configured to protrude.

[0014] In the invention according to claim 2 of the present invention, the first ball screw (1
3) and the second ball screw (15) are formed with screws in opposite directions at ends of the drive device side. The first ball screw (13) and the second ball screw (15) are connected to the drive device (2).
0, 24, 26) are screw-fitted to two nuts (16, 18) which are rotated by driving.

According to a third aspect of the present invention, in the second aspect, the two nuts (16, 18) are each provided with a pulley (20) driven by a servomotor (26). Are connected so as to rotate integrally.

In the present invention, the invention according to claim 4 is the first invention according to any one of claims 1 to 3.
An axial through hole (13a) is provided inside the ball screw (13).
Are formed, and the second ball screw (15) is inserted through the through hole (13a) movably in the axial direction.

Further, according to the fifth aspect of the present invention, the first projecting member (33) has an axially extending through hole (3) inside the first projecting member (33).
3a) and the first protruding member (3
A nut part (33b) is formed at the end of the drive part side of 3), and the second protruding member (34) is inserted movably in the axial direction into the through hole (33a) and the nut part (33b).
A screw portion (34a) formed at the drive portion side end of the second protruding member (34) is screw-fitted to the screw portion (34).
From a) the spline shaft (36) concentrically in the direction of the drive
The spline shaft (36) is spline-fitted to the spline portion (38a) so as to be rotated by the driving device, and the spline shaft (36) is
0) is always biased in the retracting direction.

According to a sixth aspect of the present invention, the spline portion (38) is provided.
a) is characterized in that it is connected so as to rotate integrally with a pulley (20) driven by a servomotor (26).

In the present invention, the gate cut pin (12) and the ejector pin (14) of the mold (30) may be connected to the ejector pin (12) when the gate cut pin (12) protrudes. 14) is retracted, and the ejector pin (14) protrudes when the gate cut pin (12) retracts. In addition, the code | symbol in said parenthesis shows the corresponding member of embodiment mentioned later.

[0020]

(First Embodiment of the Invention) A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view of the first embodiment, and FIG. 4 is an enlarged view of a gate cut pin and an ejector pin 14.

A through hole 14a is formed in the gate cut pin 12 of the mold 30 in the axial direction, and the ejector pin 14 is inserted through the through hole 14a concentrically and movably in the axial direction. I have. As shown in FIG. 4, the gate cut pin 12 and the ejector pin 14 are always urged in the retracting direction by springs 17 and 19, respectively.
The first ball screw 13 and the second ball screw 15 each having a screw formed in the opposite direction on the outer peripheral portion of the end portion on the side of the driving device can protrude. The second ball screw 15 is inserted concentrically and movably in the axial direction in a through hole 13 a penetrating in the axial direction of the first ball screw 13. The first ball screw 13 and the second ball screw 15 are 2
The two nuts 16 and 18 are screw-fitted respectively.
The nut 16 is connected to the inside of the pulley 20 so as to rotate integrally therewith, and the outer peripheral portion 16 a is rotatably supported by a support member 22 fixed to a movable platen 28.
Further, the nut 18 is connected to the outside of the pulley 20 so as to rotate integrally, and the pulley 20 is connected to be driven by a servomotor 26 via a belt 24. Since the structures of the gate cut pin 12 and the ejector pin 14 are the same as those described in the related art, the description will be omitted.

Next, the operation of the first embodiment will be described.

As shown in FIG. 1A, the gate cut pin 12 and the ejector pin 14 of the movable mold 30a in which the gate cut pin 12 and the ejector pin 14 are fixed to the movable platen 28 from the time when the mold 30 is closed to the time when the cavity filling is completed. The ball screws 13 and 15 are positioned so as to be located at a neutral position that forms a part of the surface.

Next, at the time of the gate cut shown in FIG. 1B, the servo motor 26 is driven to rotate the pulley 20 via the belt 24 in a predetermined direction. As a result, the nuts 16 and 18 rotate together with the pulley 20, and the first
The ball screw 13 moves in the protruding direction and hits the ring-shaped stopper small 21, and the ring-shaped stopper small 21 protrudes the gate cut pin 12 in the protruding direction. As a result, the gate cut operation is performed with the gate cut pins 12 protruding, and the gate of the molded product 32 is cut. In practice, the gate cut is cut on the circumference. At the same time, the second ball screw 15 moves in the retracting direction.

Next, at the time of the ejector shown in FIG. 1C, the servo motor 26 is driven to rotate the pulley 20 via the belt 24 in the opposite direction. Thereby, the nuts 16 and 18 rotate in the opposite direction to the above,
The first ball screw 13 moves in the retracting direction and separates from the ring-shaped stopper small 21. For this reason, the first spring 17
As a result, the gate cut pin 12 is retracted. At the same time, the second ball screw 15 moves in the protruding direction,
After the ball screw 13 and the second ball screw 15 return to the neutral position, the mold 30 is opened, and the servo motor 26 is further rotated. When the first ball screw 13 is further retracted, the second ball screw 15 further moves in the protruding direction and presses the ejector pin 14. At this time, the ejecting force overcomes the second spring 19 and the ejector pin 14 projects, the ejector operation is performed, and the molded product 32 is ejected.

Next, the servo motor 26 is driven to rotate the pulley 20 in a predetermined direction via the belt 24 to move the first ball screw 13 in the projecting direction and to move the second ball screw 15 in the retracting direction. By separating the ball screws 13 and 15 from the ejector pin 14 and positioning the ball screws 13 and 15 at the neutral position, the gate cut pin 12 and the ejector pin 14 are positioned at the neutral position by the spring force of the second spring 19 and the third spring 25, A series of gate cutting and ejecting operations are completed.

(Second Embodiment) FIG. 2 is a side sectional view of a second embodiment.

The same reference numerals are used for the same members and configurations as those in the first embodiment, and the description is omitted. First projecting member 33 capable of projecting gate cut pin 12
Is formed with a through hole 33a in the axial direction, and a nut portion 33b is formed at an end of the through hole 33a on the drive unit side. A second projecting member 34 capable of projecting the ejector pin 14 is provided in the through hole 33a.
And a screw portion 34a formed at an end of the second protruding member 34 on the driving portion side while being movably inserted in the axial direction.
Are screw-fitted to the nut portion 33b. From the screw portion 34a, a spline shaft 36 having a spline formed on an outer peripheral portion is concentric with the screw portion 34a and protrudes toward the drive device. The spline shaft 36 is spline-fitted to a spline portion 38a formed on the inner periphery of the rotating member 38. The rotating member 38 is connected to the inside of the pulley 20 so as to rotate integrally, and an outer peripheral portion 38 b of the rotating member 38 is rotatably supported by the support portion 22. The spline shaft 36 is inserted through the inner periphery of the pulley 20, and a spring 40 provided between the outside of the pulley 20 and the end of the spline shaft 36.
Is always biased in the retracting direction.

Next, the operation of the second embodiment will be described.

As shown in FIG. 2A, the gate cut pins 12 and the ejector pins 14 of the movable mold 30a in which the gate cut pins 12 and the ejector pins 14 are fixed to the movable platen 28 from the time when the mold 30 is closed to the time when the cavity filling is completed. The first protruding member 33 and the second protruding member 34 are positioned so as to be located at a neutral position which forms a part.

Next, at the time of gate cutting shown in FIG. 2B, the servo motor 26 is driven to rotate the pulley 20 via the belt 24 in a predetermined direction. As a result, the rotating member 38 rotates in a predetermined direction together with the pulley 20,
The spline shaft 36 and the second protruding member 34 that are spline-fitted therewith rotate integrally. Thereby, the second
The protruding member 34 does not move because the end face of the second protruding member 34 and the end face of the rotating member 38 are in contact with each other.
First projecting member 33 threadedly engaged with projecting member 34
Move in the protruding direction and hit the small ring-shaped stopper 21. The small ring-shaped stopper 21 is
And push it out in the direction. As a result, the gate cut pin 12 protrudes to perform a gate cut operation, and the molded product 3
Gate 2 is disconnected.

Next, at the time of the ejector shown in FIG. 2C, the servo motor 26 is driven to rotate the pulley 20 via the belt 24 in the opposite direction. Pulley 2
With 0, the rotating member 38 rotates in the opposite direction to the above,
The spline shaft 36 and the second protruding member 34 that are spline-fitted therewith rotate integrally. Thereby, the second
Since the projecting member 34 is pressed by the spring 40 in the retracting direction, it does not move in the projecting direction, and the first projecting member 3
3 moves in the retracting direction and moves away from the small ring-shaped stopper 21, and the gate cut pin 12 is moved in the retracting direction by the spring force of the first spring 17. Further, the first projecting member 33 is moved in the direction of the rotating member 38,
When the first projecting member 33 contacts the rotating member 38,
The movement of the first protrusion member 33 is restricted. Thereafter, when the mold 30 is opened and the pulley 20 is further rotated, the second protruding member 34 slides the spline shaft 36 against the urging force of the spring 40 and moves in the protruding direction. Is pressed in the protruding direction. This allows
The ejector pin 14 protrudes when the protruding force overcomes the second spring 19, the ejector operation is performed, and the molded product 32 is protruded.

Next, when the pulley 20 is rotated in a predetermined direction via the belt 24 by driving the servo motor 26, the second projecting member 34 moves in the retracting direction to be separated from the ejector pin 14 and the first projecting member is moved. 33 moves in the protruding direction. By positioning the first protruding member 33 and the second protruding member 34 at the neutral position, the ejector pin 14 is positioned at the neutral position by the spring force of the second spring 19, and a series of gate cutting and ejecting operations is completed.

[0034]

As described above, according to the first aspect of the present invention, one driving device (20, 24, 2) is provided.
By changing the rotation direction of 6), the gate cut pin (12) and the ejector pin (14) arranged concentrically are configured so that when one protrudes, the other retracts, so that two gate cut pins (12) and the ejector pin (14) are retracted as in the prior art. Since there is no need to provide a ball screw, these synchronous adjustments are not required, and air equipment such as an air cylinder can be omitted. Therefore, the structure of the device is simplified because the air pipe and the structure of the two ball screws are not required, so that the effect that the cost of the device can be reduced and the maintenance of the device becomes easy can be obtained.

Further, in the invention according to claim 2 of the present invention, when the two nuts (16, 18) are rotated in the same direction by the driving of the driving devices (20, 24, 26), the screws opposite to each other are rotated. (13, 15) allows each nut (1
First ball screw (13) screw-engaged with 6, 18)
When the one and the second ball screw (15) rotate in the protruding direction, the other rotates in the retracting direction.

According to a third aspect of the present invention, the pulley (20) is driven by a servomotor (26).
Rotates, the two nuts (1
6, 18) can be synchronously rotated in the same direction, so that the effect of claim 2 can be achieved with a simple configuration.

According to a fourth aspect of the present invention, the second ball screw (15) is inserted through the through hole (13a) of the first ball screw (13) so as to be movable in the axial direction. , The first ball screw (13) and the second ball screw (1
Without separating the driving device of 5), the first ball screw (1
3) and the second ball screw (15) to one drive device (2
0, 24, 26).

According to a fifth aspect of the present invention, the second protruding member (34) and the pulley (20) are connected by a spline to form one second protruding member (3).
4) and the nut portion (33) can have a gate cut function and an ejector function, respectively. Thus, the gate cut and the ejector can be performed only by changing the rotation direction of one driving device.

According to a sixth aspect of the present invention, the pulley (20) is driven by the servo motor (26).
Is rotated, the second protruding member (34) is spline-fitted to the spline portion (38a), so that when the second protruding member (34) rotates in the retracting direction, the nut portion (33) is advanced and the second protruding member (34) is advanced. 2. When the protruding member (34) rotates in the protruding direction, the spline shaft (36) can be slid to protrude the second protruding member (34).

Further, the invention according to claim 7 of the present invention is characterized in that the gate cut pin (12) and the ejector pin (1)
4) When one protrudes, the other is retracted, so that the structure of the device can be simplified, the cost of the device can be reduced, and further, the maintenance of the device can be facilitated.

[Brief description of the drawings]

FIG. 1A is a side sectional view showing a first embodiment,
(B) is a side sectional view showing a state at the time of a gate cut operation of the first embodiment, and (c) is a side sectional view showing a state at the time of an ejector operation of the first embodiment.

FIG. 2A is a side sectional view showing a second embodiment,
(B) is a side sectional view showing a state at the time of a gate cut operation of the second embodiment, and (c) is a side sectional view showing a state at the time of an ejector operation of the second embodiment.

FIG. 3A is a side sectional view showing a conventional technique, FIG. 3B is a side sectional view showing a state at the time of a gate cutting operation of the related art,
(C) is a side sectional view showing a state at the time of an ejector operation in the related art.

FIG. 4 is a side sectional view showing a detailed structure of a gate cut pin and an ejector pin portion according to the first embodiment, the second embodiment, and the prior art.

[Explanation of symbols]

12 gate cut pin 13 first ball screw 13a through hole 14 ejector pin 15 second ball screw 16
Nut 16a Outer periphery 18 Nut 20 Pulley 22
Support member 24 Belt 26 Servo motor 28 Moving plate

Claims (7)

[Claims] 1. A gate cut pin (1) of a mold (30).
2) and the first ball screw (13) and the second ball screw (15) of the injection molding machine (10) for driving the ejector pin (14), respectively, are arranged concentrically,
The first ball screw (13) and the second ball screw (15) are driven by one driving device (20, 24, 26),
The second ball screw (15) retracts when the first ball screw (13) protrudes, and the second ball screw (15) when the first ball screw (13) retracts, depending on the rotation direction of the driving device (20, 24, 26). A gate cutting and projecting device for an injection molding machine, characterized in that the gate cutting and projecting devices are configured to project. 2. The drive device side ends of the first ball screw (13) and the second ball screw (15) are formed with screws in opposite directions, respectively. 2. The injection molding machine according to claim 1, wherein the ball screw (15) is screw-fitted to each of two nuts (16, 18) rotated by the drive of the driving device (20, 24, 26). Gate cutting and protruding device. 3. A pulley (2) driven by a servomotor (26), respectively.
3. The gate cutting and projecting device of an injection molding machine according to claim 2, wherein the gate cutting and projecting device is connected so as to rotate integrally with the injection molding machine. 4. A through hole (13a) is formed in the first ball screw (13) in the axial direction.
4. A gate cutting and projecting device for an injection molding machine according to claim 1, wherein a second ball screw (15) is inserted through a) so as to be movable in the axial direction. 5. A through hole (33a) is formed in the first protruding member (33) in the axial direction, and a nut portion (33b) is formed at an end of the first protruding member (33) on the side of the driving unit. Are formed, and the second projecting member (3) is inserted into the through hole (33a).
4) is inserted movably in the axial direction, and a screw portion (34a) formed at the drive portion side end of the second protruding member (34) is screwed into the nut portion (33b). A spline shaft (36) projects concentrically from the screw portion (34a) toward the driving device, and the spline shaft (36) is rotated by the driving device.
And the spline shaft (36) is
A gate cutting and projecting device for an injection molding machine, which is constantly urged in a retracting direction by a spring (40). 6. The gate of an injection molding machine according to claim 5, wherein the spline portion (38a) is connected so as to rotate integrally with a pulley (20) driven by a servomotor (26). Cutting and overhanging device. 7. A gate cut pin (1) of a mold (30).
2) and the ejector pin (14) is characterized in that when the gate cut pin (12) protrudes, the ejector pin (14) retracts, and when the gate cut pin (12) retracts, the ejector pin (14) protrudes. Cutting and protruding method of injection molding machine.