JP4485928B2 - Injection molding machine - Google Patents

Description

  The present invention relates to a horizontal inline screw type injection molding machine, and more particularly to the structure of an injection system mechanism in a horizontal type inline screw type injection molding machine.

  In a horizontal type in-line screw type injection molding machine, conventionally, a structure in which a screw is rotatably held and a moving body that moves forward and backward integrally with the screw is inserted and guided through two or four tie bars. It was common to take.

  By the way, if there are two tie bars that are inserted through the moving body and guide the moving body, it is necessary to secure a large tie bar pitch in order to stably guide the moving body. For this reason, both ends of the tie bar are fixed. The horizontal dimensions of the holding plate and the moving body are also increased accordingly, and the mechanism is prevented from being made compact. Moreover, since the weight of the moving body increases, the rotational torque of the injection driving system (driving system that moves the moving body linearly) increases. Also, in this type of inline screw type injection molding machine, a pair of servo motors for injection is often provided, but the two tie bars are positioned at the intermediate position in the vertical direction (height direction) of the holding plate and the moving body. Therefore, the injection servo motor must be arranged outside the tie bar, and this further hinders the compactness of the mechanism.

  On the other hand, if there are four tie bars that pass through the moving body and guide the moving body, the pitch between adjacent tie bars can be reduced, but an injection servo motor is provided between the upper and lower tie bars. This also makes it difficult to make the mechanism compact. Also, if there are four tie bars, due to the length error of each tie bar (length error within the tolerance range), three of the four tie bars in the quadrangular arrangement and the other one An imbalance tends to occur in the way the force is received. For this reason, the injection pressure acts unevenly, which may cause screw galling or cause the injection pressure to become unstable.

  The present invention has been made in view of the above points, and an object thereof is to make the injection system mechanism in a horizontal in-line screw type injection molding machine compact.

In order to achieve the above-described object, the present invention provides a first holding plate that holds the base end portion of the heating cylinder, a second holding plate that faces the first holding plate at a predetermined distance, and the first holding plate. A moving body capable of moving back and forth between the plate and the second holding plate, a screw that moves back and forth integrally with the moving body, and a rotational force generated by a servo motor for injection is converted into a linear moving force, A ball screw mechanism that transmits to the moving body, one end of which is fixed to the first holding plate, and the other end is fixed to the second holding plate, and the first holding plate and the second holding plate are coupled and injected. a tie bar that receives the pressure, the first holding plate in the second holding plate and horizontal line screw type injection molding machine having a base plate for supporting the movable body, the movable The tie bar not inserted, and in the total weight of the movable body, thereby supporting at rail member which is fixed to the base plate via a linear bearing member, a three the number of the tie bar, These three tie bars are arranged at the positions of the apexes of an inverted equilateral triangle when viewed in a plane perpendicular to the axis of each tie bar .
In addition, two injection servomotors are provided, and the screw is driven forward and backward by two injection servomotors, and two tie bars located above the three tie bars The configuration is such that at least a part of the two injection servomotors is disposed below the servomotor .
Further, the lower part of the measuring servo motor for rotationally driving the screw is arranged between the two tie bars located on the upper side of the three tie bars .

  According to the present invention, since the structure of the tie bar of the injection system mechanism is three, it becomes possible to easily arrange the servo motor under the tie bar or between the tie bars, and to make the injection system mechanism compact. Can do. In addition, since it has a three-tie structure with triangular arrangement at equal intervals on the same circumference, each tie bar is evenly spaced with three-point support at equal intervals even if there is an error within the tolerance in the length of each tie bar. The injection pressure can be received, and there is no possibility of causing galling in the screw or instability of the injection pressure.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 5 relate to an injection molding machine according to an embodiment of the present invention (hereinafter referred to as the present embodiment), and FIG. 1 is a perspective view showing the overall appearance of the injection molding machine of the present embodiment.

  In FIG. 1, 1 is a base board, 2 is an injection system mechanism, and 3 is a mold opening / closing system mechanism. In the injection system mechanism 2, 4 is a front holding plate, 5 is a rear holding plate arranged to face the front holding plate 4 at a predetermined distance, and 6 is fixed at the base end to the front holding plate 4. A heating cylinder 7 in which a screw (not shown) is arranged so as to be able to rotate and move back and forth inside is provided with three tie bars 8 laid between the front holding plate 4 and the rear holding plate 5. Is a movable body capable of moving back and forth between the front holding plate 4 and the rear holding plate 5, 9 is a servo motor for weighing mounted on the moving body 8, and 10 is mounted on the rear holding plate 5. A pair of servo motors for injection (only one servo motor 10 is shown in FIG. 1). The movable body 8 rotatably holds a rotating body (not shown) in which a base end portion of a screw (not shown) is fixed, and a driven large pulley 15 which is integrated with the rotating body is used as a servo for measurement. The screw is rotated by being driven to rotate by the motor 9. One end of a linear moving member (here, a nut body) 11 of a ball screw mechanism is fixed to the moving body 8, and is screwed into the linear moving member 11 and is rotatably held by the rear holding plate 5. The driven large pulley 20 described later, which is fixed to a rotating member (here, a screw shaft) of the ball screw mechanism, is driven to rotate by an injection servo motor 10 so that the moving body 8, a rotating body (not shown), a screw, etc. Is designed to move linearly.

  In the mold opening / closing system mechanism 3, 31 is a mold opening / closing drive source holding plate, 32 is a fixed die plate on which a fixed mold (not shown) is mounted, and 33 is a mold opening / closing drive source holding plate 31 and a fixed die plate 32. The three tie bars 34 spanned between the two are mounted on a movable die (not shown), and are movable die plates capable of moving back and forth between the mold opening / closing drive source holding plate 31 and the fixed die plate 32, Reference numeral 35 denotes a mold opening / closing servomotor mounted on the mold opening / closing drive source holding plate 31, and 36 is a toggle link mechanism for moving the movable die plate 34 forward / backward by being driven to extend or fold. Note that one end of a linear movement member (not shown) of a ball screw mechanism (not shown) is fixed to the cross head, which is the force input end of the toggle link mechanism 36, and is screwed into the linear movement member (here, a screw shaft) and A driven large pulley (not shown) fixed to a rotating member (here, a nut body) of a ball screw mechanism rotatably held by a mold opening / closing drive source holding plate 31 is driven to rotate by a servo motor 35 for mold opening / closing. Thus, the movable die plate 34 is driven by the toggle link mechanism 36 after being advanced.

  FIG. 2 shows a rotation transmission mechanism from the measuring servo motor 9 to the driven large pulley in the injection molding machine according to the present embodiment. It is a principal part perspective view of the state which omitted one etc. of the rods. In FIG. 2, 13 is a rotating shaft of the servo motor 9 for metering, 14 is a small driving pulley (toothed pulley) fixed to the rotating shaft 13, and 15 is the above-described fixing the base end of a screw (not shown). A driven large pulley (toothed pulley) 16 integrated with a rotating body (not shown), 16 is a timing belt (toothed belt) wound around the driven small pulley 14 and the driven large pulley 15, and 17 is a driven small pulley 14. The cover body covers the timing belt 16 and the driven large pulley 15. The rotation of the rotating shaft 13 of the measuring servo motor 9 is transmitted from the small driving pulley 14 to the driven large pulley 15 via the timing belt 16, whereby the screw (not shown) rotates as described above.

  FIG. 3 is a perspective view of a principal part in a state where a part thereof is broken to show the rotation transmission mechanism from the servo motor 10 for injection to the driven large pulley in the injection molding machine of the present embodiment. In FIG. 3, only one rotation transmission mechanism of the pair of servo motors 10 for injection is shown, but the same applies to the rotation transmission mechanism of the other servo motor 10. In FIG. 3, 18 is a rotating shaft of the servomotor 10 for injection, 19 is a small driving pulley (toothed pulley) fixed to the rotating shaft 18, and 20 is screwed to the linear moving member 11 of the ball screw mechanism described above. The driven large pulley (toothed pulley) 21 fixed to the rotating member 12 of the ball screw mechanism rotatably held by the rear holding plate 5 is wound around the driving small pulley 19 and the driven large pulley 20. The timing belt (toothed belt) 22 is a cover that covers the small driving pulley 19, the timing belt 21, and the driven large pulley 20. The rotation of the rotating shaft 18 of the pair of servo motors 10 for injection is synthesized and transmitted from the small driving pulley 19 to the large driven pulley 20 via the timing belt 21, thereby the ball screw mechanism. As described above, the moving body 8, the rotating body (not shown), the screw, and the like are driven forward and backward through the (rotating member 12 → linearly moving member 11).

  FIG. 4 is a perspective view of a main part corresponding to FIG. 2 in a state in which a servo motor for nozzle touch / back and its driving pulley are omitted. 2 to 4, reference numeral 41 denotes a pair of parallel rail members fixed on the base board 1. Reference numeral 42 denotes a lower part of the front holding plate 4 which is fixed and supported, and can be linearly moved on the rail member 41. The linear motion bearing members (FIGS. 2 to 4) and 43 engaged with the rail member 41 are fixed and supported at the lower part of the rear holding plate 5 so that the linear movement on the rail member 41 is possible. Linear motion bearing members (FIG. 3) and 44 engaged with the rail member 41 are engaged with the rail member 41 so as to fix and carry the lower part of the movable body 8 and to allow linear motion on the rail member 41. It is a linear motion bearing member (FIGS. 2 to 4). In the present embodiment, the three tie bars 7 are not inserted through the moving body 8, and the moving body 8 has a completely free relationship with the tie bar 7. The linear motion bearing member 44 is supported by the linear motion bearing member 44 so that the linear motion bearing member 44 can move linearly between the front holding plate 4 and the rear holding plate 5. Also, a front holding plate 4 and a rear holding plate 5 connected by three tie bars 7, and a moving body connected to the rear holding plate 5 via a ball screw mechanism (rotating member 12, linear moving member 11). 8, that is, the front holding plate 4, the rear holding plate 5, the movable body 8 and the members mounted on them (that is, the injection system mechanism 2 that is an injection unit) are integrated into The linear touch member 42, 43, 44 can move linearly on the rail member 41 by the driving force of the servo motor for nozzle touch / back.

  In FIG. 3, 51 is a pair of nozzle touch / back servomotors mounted on the front holding plate 4, and 52 is a drive fixed to the rotation shaft of each servomotor 51 for nozzle touch / back. Pulleys 53 are rotatably held by the front holding plate 4, and are driven pulleys and nut bodies integrated with a nut body of a ball screw mechanism that transmits the rotation of the drive pulley 52 via a timing belt (not shown). Reference numeral 54 denotes a pair of nozzle touch / back rods whose one end is fixed to the fixed die plate 32 and whose threaded portion is screwed to the driven pulley / nut body 53. In FIG. 3, only the servo motor 51, the driving pulley 52, and the driven pulley / nut body 53 on one side are shown. The rotation of the servo motor for nozzle touch / back is transmitted to the driven pulley / nut body 53 by the driving pulley 52 and a timing belt (not shown), and the driven pulley / nut body 53 is rotated so that the screw portion (ball screw mechanism The nozzle touch / back rod 54 in which the threaded portion) is screwed to the driven pulley / nut body 53 is moved forward and backward relative to the driven pulley / nut body 53, whereby the entire injection system mechanism 2 is moved to the rail member. Go forward and backward along 41. In the continuous molding operation, a nozzle touch state in which the nozzle (not shown) at the tip of the heating cylinder 6 is pressed against the resin inlet of the fixed mold (not shown) at the position where the injection system mechanism 2 has advanced. Is supposed to take. Further, in the nozzle back state, the injection system mechanism 2 is retracted so that the nozzle (not shown) at the tip of the heating cylinder 6 is separated from the resin inlet of the fixed mold (not shown). .

  FIG. 5 is a diagram showing an arrangement relationship between the tie bar 7, the moving body 8, the measuring servomotor 9, and a pair of injection servomotors 10. In addition, in FIG. 5, the moving body 8 has drawn the cross section of the intermediate part with the dashed-two dotted line.

  As shown in FIG. 5, the three tie bars 7 are arranged in an inverted triangle as viewed in a plane orthogonal to the axis of the tie bar, and the tie bars 7 are arranged at equal intervals on the same circumference. As described above, the tie bar 7 and the moving body 8 have a completely free relationship. That is, the tie bar 7 does not have a function as a member that inserts the moving body 8 and supports the weight of the moving body as in the prior art, and connects the front holding plate 4 and the rear holding plate 5 integrally to reduce the injection pressure. It is only responsible for receiving functions. With this configuration, the tie bar is inserted through the moving body as in the past, and the moving body is provided with a bush for sliding the tie bar. Compared to this, a very clean configuration can be achieved. Further, since the tie bar is inserted through the moving body as in the prior art and the weight of the moving body is applied to a ball screw mechanism that moves the moving body back and forth, the moving body 8 is compared with the ball screw that is subjected to bending stress. Since the entire weight is supported on the rail member 41 via the linear motion bearing member 44, there is no possibility that bending stress is applied to the ball screw. Furthermore, because it has a three-tie structure with triangular arrangement at equal intervals on the same circumference, even if there is an error within the tolerance in the length of each tie bar, each tie bar is almost even with three-point support at equal intervals. Therefore, there is no possibility of causing galling in the screw or instability of the injection pressure.

  Further, as shown in FIG. 5, in this embodiment, at least a part of the two injection servomotors 10 is positioned below the two tie bars 7 located on the upper side of the three tie bars 7, respectively. The lower part of the measuring servo motor 9 is positioned between the two tie bars 7 located on the upper side of the three tie bars 7. Accordingly, since the three servo motors are arranged near the center of the injection system mechanism 2, the injection system mechanism 2 can be made compact.

It is a perspective view showing the whole appearance of the injection molding machine concerning one embodiment of the present invention. In order to show a rotation transmission mechanism from a measuring servo motor to a driven large pulley in an injection molding machine according to an embodiment of the present invention, a perspective view of a main part in a state where a part is broken and a part of the members is omitted FIG. FIG. 3 is a perspective view of a principal part in a state where a part thereof is broken to show a rotation transmission mechanism from an injection servo motor to a driven large pulley in an injection molding machine according to an embodiment of the present invention. It is a principal part perspective view of the state which omitted the one part member corresponding to FIG. 2 in the injection molding machine which concerns on one Embodiment of this invention. It is explanatory drawing which shows the arrangement | positioning relationship between a tie bar, the mobile body, the servomotor for measurement, and a pair of servomotor for injection in the injection molding machine which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base board 2 Injection system mechanism 3 Type | mold opening / closing system mechanism 4 Front side holding plate 5 Rear side holding plate 6 Heating cylinder 7 Tie bar 8 Moving body 9 Servo motor for measurement 10 Servo motor for injection 11 Linear moving member of ball screw mechanism 12 Ball screw Rotating member of mechanism 13 Rotating shaft of servo motor for metering 14 Driven small pulley 15 Driven large pulley 16 Timing belt 17 Cover body 18 Rotating shaft of servomotor for injection 19 Driven small pulley 20 Driven large pulley 21 Timing belt 31 Opening / closing of mold Drive source holding plate 32 Fixed die plate 33 Tie bar 34 Movable die plate 35 Servo motor for opening and closing mold 36 Toggle link mechanism 41 Rail member 42, 43, 44 Linear motion bearing member 51 Servo motor for nozzle touch / back 52 Drive pulley 3 driven pulley and nut 54 nozzle touch / back rod

Claims (3)

A first holding plate that holds the base end of the heating cylinder, a second holding plate that faces the first holding plate at a predetermined distance, and a front and rear between the first holding plate and the second holding plate A movable body that can advance, a screw that moves back and forth integrally with the movable body, a ball screw mechanism that converts a rotational force by a servo motor for injection into a linear moving force and transmits the linear moving force to the movable body, and one end thereof A tie bar which is fixed to the first holding plate and whose other end is fixed to the second holding plate and which combines the first holding plate and the second holding plate to receive an injection pressure; and the first holding plate; In a horizontal inline screw type injection molding machine provided with a base board for supporting the second holding plate and the movable body,
The tie bar is not inserted into the moving body , and the entire weight of the moving body is supported by a rail member fixed to the base board via a linear motion bearing member.
An injection molding machine characterized in that the number of tie bars is three and these three tie bars are arranged at the apexes of inverted equilateral triangles when viewed in a plane perpendicular to the axis of each tie bar . The injection molding machine according to claim 1,
Two injection servo motors are provided so that the screw is driven forward and backward by two injection servo motors, and below the two tie bars located above the three tie bars. An injection molding machine characterized in that at least a part of the two servo motors for injection is arranged . The injection molding machine according to claim 1 ,
An injection molding machine characterized in that a lower part of a measuring servo motor for rotationally driving the screw is arranged between two tie bars located on the upper side of the three tie bars .

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