JP2009143028A - Power transmission mechanism of molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate the adjustment of the tension of a molding machine in the power transmission mechanism of a molding machine constituted so that the belt is trained over the drive pulley attached to the drive shaft of a motor and a follower pulley to get rotary motion converted to direct-acting motion by the ball screw mechanism attached to the follower pulley. <P>SOLUTION: In the power transmission mechanism 34 of the molding machine constituted so that the belt 32 is trained over the drive pulley 23 attached to the drive shaft 22 of the motor 19 and the follower pulley 26 to get the rotary motion converted to the direct-acting motion by the ball screw mechanism 28 attached to the follower pulley 26, the idler pulley 43 attached to the shaking member 42 shaken centering around a mandrel 41 is brought into contact with the belt 32. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention provides a power for a molding machine in which a belt is stretched between a drive pulley and a driven pulley attached to a drive shaft of a motor, and a rotational motion is converted into a linear motion by a ball screw mechanism attached to the driven pulley. It relates to a transmission mechanism.

In an ejector device, a mold opening / closing device, a mold clamping device, an injection device, and various linear motion mechanisms provided in a molding machine such as an injection molding machine or a press molding machine, the rotational motion of a motor is driven by a drive pulley, belt, driven pulley. In many cases, the rotary motion is transmitted to the ball screw mechanism and converted into a linear motion. In the above, the rotation of the drive shaft of the motor needs to be transmitted to the driven pulley through the belt without delay, and in order to prevent tooth skipping which is the idling of the drive pulley, a predetermined tension is applied to the belt. It is necessary to grant. As a method of applying tension to the belt, a method of applying tension to the belt by adjusting the mounting position of the motor as shown in FIG. 4 is known. However, this method has a problem that the belt tension changes before and after the motor is fully tightened to the molding machine by the fixing bolt because the motor mounting plate is inclined due to the weight of the motor. Adjustment was difficult. In addition to the above, after the motor is fixed to the molding machine side, tension is applied to the belt by an idler pulley. In FIG. 5, the tension of the belt of the ejector device is adjusted by an idler pulley provided on the back surface of the movable platen and its adjusting mechanism. However, this method requires a space for providing an adjustment mechanism on the back surface of the movable plate and also requires a plurality of push-pull bolts. Further, in the case shown in FIG. 5, when adjusting the belt tension, it is necessary to perform tightening work such as bolts in a narrow space between the back of the movable platen and the mold clamping device. In addition, there is a problem that the operator easily gets dirty with grease or the like.

Moreover, in the power transmission mechanism of an ejector apparatus, the thing of patent document 1 and patent document 2 is well-known as what applies tension | tensile_strength to a belt with an idler pulley. In Patent Document 1, idler pulleys (tension pulleys) are respectively disposed between a driving pulley and a driven pulley attached to a driving shaft of a motor, and between a driven pulley and a driving pulley of the motor. In Patent Document 2, an idler pulley is disposed between the driven pulley and the driven pulley. However, there is no specific description on how to attach the idler pulley to the movable platen. As far as the figure is concerned, it seems that the idler pulley is simply fixed to the movable platen with a bolt, but it is difficult to accurately apply tension to the belt. In addition, since tension is applied to the belt from the inside to the outside by the idler pulley, the ratio of the belt engaging with the drive pulley is reduced particularly in Patent Document 1, which may cause tooth skipping. It was.

Japanese Unexamined Patent Publication No. 7-9507 (0012, FIG. 2) JP 2001-71357 A (0015, FIG. 1)

In the present invention, in view of the above problems, a belt is stretched between a drive pulley and a driven pulley attached to a drive shaft of a motor, and a rotary motion is converted into a linear motion by a ball screw mechanism attached to the driven pulley. An object of the present invention is to provide a power transmission mechanism for a molding machine that facilitates belt tension adjustment.

According to a first aspect of the present invention, there is provided a power transmission mechanism for a molding machine in which a belt is stretched between a driving pulley attached to a driving shaft of a motor and a driven pulley, and is rotated by a ball screw mechanism attached to the driven pulley. In a power transmission mechanism of a molding machine in which motion is converted into linear motion, an idler pulley attached to a swinging member that can swing around a support shaft is brought into contact with the belt at the time of adjustment. It is provided.

The power transmission mechanism of the molding machine according to claim 2 of the present invention is the molding machine according to claim 1, wherein the molding machine is an injection molding machine, and the power transmission mechanism of the ejector device is provided on the back surface or inside of the movable platen or fixed platen. It is characterized by being.

In the power transmission mechanism of the molding machine according to the present invention, a belt is stretched between a drive pulley and a driven pulley attached to a drive shaft of a motor, and a rotational motion is converted into a linear motion by a ball screw mechanism attached to the driven pulley. In the power transmission mechanism of the molding machine to be converted, the belt is provided with an idler pulley attached to a swinging member that can swing around the support shaft. The tension adjustment mechanism has a simple structure, making it easier to adjust the belt tension.

The power transmission mechanism of the molding machine of this invention is demonstrated with reference to FIG. 1 and FIG. FIG. 1 is a side view of a power transmission mechanism of the molding machine according to the present embodiment. FIG. 2 is a front view of the power transmission mechanism of the molding machine of the present embodiment. FIG. 3 is an enlarged cross-sectional view taken along line AA in FIG.

As shown in FIGS. 1 and 2, the injection molding machine of this embodiment includes an injection device (not shown) and a mold clamping device. In the mold clamping device, four tie bars 11 are arranged between a fixed plate and a pressure receiving plate (not shown). A movable platen 12 is slidably disposed on the tie bar 11, and a movable mold 14 is attached to a surface of the main body 13 of the movable platen 12 on the fixed platen side. A toggle mechanism is disposed between the pressure receiving plate and the movable platen 12. The toggle link 15 of the toggle mechanism is attached to the upper and lower shaft support portions 16 on the back surface of the movable platen 12. The upper and lower shaft support portions 16 are connected by a connecting plate 17. Therefore, a space is formed between the connecting plate 17 of the movable platen 12 and the main body 13. The mold clamping device is not limited to a toggle mechanism, and the drive source may be a motor or hydraulic pressure.

As shown in FIGS. 1 to 3, the movable platen 12 is provided with an ejector device 18 that projects a molded product that is stuck to the movable mold 14 when the mold is opened. A bracket 20 is formed on the back surface of the main body 13 on the side opposite to the operation side of the movable platen 12 (left side in FIG. 2) so as to project toward the pressure platen side. A motor mounting plate 21 for attaching a servo motor 19 for driving the ejector device 18 is fixed to the front surface of the bracket 20 by a bolt toward the non-operation side. The motor mounting plate 21 is provided with a hole 21c through which a motor drive shaft 22 is inserted into a rectangular main body 21a. Further, as shown in FIG. 2, a protruding portion 21b is formed on the lower side of the main body portion 21a so that a portion that becomes the machine center side at the time of attachment projects downward from the non-operation side. The shape of the motor mounting plate 21 may be a shape in which the machine center side protrudes from the counter-operation side of the plate. Or, in other words, the shape may be a shape in which the counter-operation side is retracted toward the motor side rather than the machine center side. Therefore, the motor mounting plate 21 may be substantially T-shaped or may have a shape with a recess in part. A servo motor 19 is fixed to the fixed plate side (left side in FIG. 1) of the motor mounting plate 21 with a bolt, and the drive shaft 22 of the servo motor 19 is directed toward the pressure receiving plate side (right side in FIG. 1). It protrudes. A toothed drive pulley 23 is fixed to the drive shaft 22.

Further, the connecting plate 17 has a shaft portion 24a at one end of the ball screw 24 which is rotatable by a bearing 25 and cannot be moved in the axial direction on the operation side (right side in FIG. Installed on. A part of the shaft portion 24a extends toward the pressure receiving plate side with respect to the connecting plate 17, and a toothed driven pulley 26 is fixed to the shaft portion 24a.

Further, as shown in FIG. 1, the shaft portion (not shown) at the other end of the ball screw 24 is pivotally supported by the main body portion 13 of the movable platen 12 so as to be rotatable and not movable in the axial direction. A ball nut 27 is inserted into the ball screw 24 in the cavity between the connecting plate 17 and the main body 13, and the ball screw 24 and the ball nut 27 constitute a ball screw mechanism 28. The ball nut 27 is fixed to an ejector plate 29 provided in parallel to the connecting plate 17 in the hollow portion. A large number of ejector pins 30 to be inserted into the insertion holes of the main body 13 are fixed to the ejector plate 29. A guide shaft 31 is fixed between the connecting plate 17 and the main body 13. As shown in FIG. 2, one guide shaft 31 is disposed on the lower side of the operation side and on the upper side of the non-operation side on the back surface of the movable platen 12. The guide shaft 31 is slidably inserted into a hole provided in the ejector plate 29.

A belt 32 having teeth formed on the inner side is stretched between the driving pulley 23 and the driven pulley 26. Needless to say, the teeth of the drive pulley 23, the driven pulley 26, and the belt 32 are all provided in the mold opening / closing direction. The servo motor 19, the drive shaft 22 of the servo motor 19, the drive pulley 23, the belt 32, the driven pulley 26, a ball screw mechanism 28 including a ball screw 24 and a ball nut 27, an ejector plate 29, an ejector pin 30, and the like, which will be described later. A power transmission mechanism 34 of the ejector device 18 is constituted by the tension adjustment mechanism 33 and the like. The operation of the power transmission mechanism 34 of the ejector device 18 during molding will be briefly described. In the injection molding machine, when the mold is opened after the molding is completed, the ejector device 18 is operated. During the operation of the ejector device 18, when the drive shaft 22 and the drive pulley 23 of the servo motor 19 are driven to rotate, the rotation is transmitted to the driven pulleys 26 and 26 via the belt 32. When the ball screws 24, 24 of the ball screw mechanisms 28, 28 are rotated, the rotational motion is converted into linear motion, and the ball nuts 27, 27 are moved toward the stationary platen, and the ejectors fixed to the ball nuts 27, 27 are used. The plate 29 and the ejector pin 30 also move in the same direction, and the molded product P is ejected through the plate 35 and the projecting pin 36 in the movable mold 14. At this time, the drive pin 22 of the servo motor 19 is rotationally driven in the opposite direction, whereby the ejector pin 30 is retracted, and the projecting pin 36 is retracted due to the action of the spring biasing force in the movable mold 14.

Next, the belt tension adjusting mechanism 33 of this embodiment will be described. The belt tension adjusting mechanism 33 is provided so that an idler pulley 43 attached to a swinging member 42 that can swing around a shoulder bolt 41 that is a support shaft at the time of adjustment is in contact with the belt 32. Yes. As a specific structure, a screw hole 44 for attaching the shoulder bolt 41 is provided in the mold opening / closing direction in the overhanging portion 21 b protruding downward in the motor mounting plate 21. On the opposite side (left side in FIG. 2), a long hole 45 used for fixing after adjusting the angle of the swinging member 42 penetrates the protruding portion 21b so that the vertical direction is the longitudinal direction. It is provided in the mold opening / closing direction. Accordingly, the projecting portion 21b is divided into approximately three equal parts in the horizontal direction, and a screw hole 44 is provided at a position about 1/3 from the machine center side, and a long hole 45 is provided at a position about 1/3 from the counter-operation side. .

A swinging member 42 is attached to the surface of the overhanging portion 21b on the fixed platen side so as to be swingable around the support shaft during adjustment. As shown in FIG. 3, the swinging member 42 is an L-shaped member having a predetermined thickness, and an idler pulley 43 rotates around the mold opening / closing direction as a central axis via a bearing 43a on the pressure receiving plate side at one end. Arranged freely. Accordingly, the belt 32 is pressed by the idler pulley 43 inward between the driven pulley 26 and the drive pulley 23 to apply tension. Further, by providing the idler pulley 43 at this position, the portion where the belt 32 abuts against the drive pulley 23 can be increased, and tooth skipping can be prevented. The idler pulley 43 has no teeth on the outer peripheral surface corresponding to the outer surface of the belt 32 being a flat surface.

A through hole 46 which is not threaded is formed at a position corresponding to the screw hole 44 of the overhanging portion 21b at a substantially central portion of the swing member 42. A screw hole 47 is formed at a position corresponding to the elongated hole 45 of the overhanging portion 21b at a position slightly opposite to the operation side from the central portion of the swing member 42. The other end of the swinging member 42 is L-shaped, and is provided with a protruding portion 48 that protrudes toward the pressure receiving plate when attached to the overhanging portion 21b. The projecting portion 48 is formed with a threaded hole 49 penetrating in a direction perpendicular to the through hole 46 and being substantially vertical when attached.

As described above, the swinging member 42 can be mounted on the overhanging portion 21b of the motor mounting plate 21 at the time of adjustment around the shoulder bolt 41 that is a support shaft. Installed on. The shoulder bolt 41 is inserted through the washer 54 from the fixed platen side of the swing member 42. The shoulder bolt 41 has a threaded portion 41a engaged with a threaded hole 44 in the overhanging portion 21b, and a body portion 41b slidably inserted into the through-hole 46 in the swinging member 42. A bolt 50 is screwed into the screw hole 47 of the swing member 42 from the fixed platen side through a washer 55 and is inserted into the long hole 45 of the overhanging portion 21b. And the part which the volt | bolt 50 protruded from the long hole 45 to the receiving pressure board side is being fixed with the nut 51. FIG. Further, an adjustment bolt 52 is inserted into the screw hole 49 of the protrusion 48 of the swing member 42. The adjusting bolt 52 is a grab screw bolt having a spherical bearing in the head portion 52a. The contact surface of the adjuster bolt 52 with the head portion 52 a is in surface contact with the lower surface 21 d of the main body portion 21 a of the motor mounting plate 21. The screw portion 52 b of the adjuster bolt 52 is screwed into the screw hole 49 of the protruding portion 48. A nut 53 screwed into the threaded portion 52 b of the adjuster bolt 52 is in contact with the lower surface of the protruding portion 48. The adjuster bolt 52 may be a general bolt that does not have a spherical bearing. In addition to adjusting the position by rotating the nut, the swinging member 42 may be adjusted by rotating the bolt or other mechanism.

The position of the shoulder bolt 41 and the adjuster bolt 52, which are adjusting members of the belt tension adjusting mechanism 33, is arranged between the upper and lower tie bars 11, 11 or on the side opposite to the operation side than the tie bars 11, 11. It is desirable for work to be outside. And even if the mounting bracket for mounting the motor that drives the ejector device projects directly to the non-operating side as a part of the movable platen, by providing the movable plate or a support shaft for mounting the swinging member on the bracket, A tension adjusting mechanism can be provided.

Next, the tension adjusting operation of the belt 32 by the belt tension adjusting mechanism 33 will be described. At the time of adjustment, first, the swing member 42 into which the adjuster bolt 52 has already been inserted is swingably mounted on the overhanging portion 21b of the motor mounting plate 21 by the shoulder bolt 41. In this state, the shoulder bolt 41 is not yet tightened firmly. Next, the motor mounting plate 21 is attached to the screw portion 52b of the adjuster bolt 52 below the protruding portion 48 in a state where the contact surface of the head portion 52a of the adjuster bolt 52 is in contact with the lower surface 21d of the main body portion 21a. Turn the nut 53 to adjust the position. By adjusting the position of the nut 53, the protruding amount of the adjuster bolt 52 upward from the protruding portion 48 can be adjusted. At this time, since the head portion 52a of the adjusting bolt 52 can be swung by a spherical bearing, the contact surface and the lower surface 21d of the main body portion 21a are stably in surface contact. The swing member 42 swings around the shoulder bolt 41 serving as a fulcrum by applying a force from the contact surface of the head portion 52a of the adjuster bolt 52 serving as a power point toward the lower surface 21d of the main body portion 21a. Then, the outer peripheral surface of the idler pulley 43 serving as the point of action is in strong contact with the outer surface of the belt 32. The operator adjusts the position of the nut 53 with respect to the threaded portion 52b of the adjuster bolt 52 so that the tension of the belt 32 becomes a recommended value.

The tension of the belt 32 is appropriately measured by a non-contact type tension meter that measures the frequency of the belt. When the tension of the belt 32 is adjusted, the swing member 42 and the motor mounting plate 21 are firmly fixed. Specifically, the shoulder bolt 41 inserted through the swing member 42 and the overhanging portion 21 b is tightened via the washer 54. Further, the bolt 50 inserted through the screw hole 47 and the long hole 45 is tightened between the nut 51 with the washer 55, the swinging member 42, and the overhanging portion 21b interposed therebetween. The bolt 50 may be inserted later. In this way, the swing member 42 is fixed so as not to swing at the three points of the adjuster bolt 52, the shoulder bolt 41, and the bolt 50, so that the tension of the belt 32 can be maintained. The bolt 50 is not essential, and other fixing means may be provided.

As described above, by adjusting the tension of the belt 32 by the idler pulley 43, the present invention has one or more of the following advantages. First, compared with the motor that adjusts the mounting position of the motor, the operator's force when turning the bolt or nut is small, and the number of adjustment bolts for adjustment is greatly reduced (one in this embodiment). . In the present invention, the accuracy of the tension of the belt 32 can be increased. The adjustment time for adjusting the belt tension can be shortened. Furthermore, since the operator can perform operations such as adjusting bolts at positions outside the axis of the upper and lower tie bars, the operator also needs to put a body between the movable platen and the mold clamping device. Since it decreases, the work is less likely to get dirty and can be easily operated. Further, since the belt tension adjusting mechanism 33 can be provided by using the motor mounting plate 21 provided on the non-operation side, there is no need to provide a dedicated bracket or the like, and the belt tension adjusting mechanism 33 has a simple structure. can do.

The present invention is not enumerated one by one, but is not limited to that of the above-described embodiment, and it goes without saying that those skilled in the art also apply modifications made in accordance with the spirit of the present invention. is there.

The position where the idler pulley of the power transmission mechanism is installed is between the drive pulley and the driven pulley on the side where the belt is sent when the ejector pin protrudes, or between the drive pulley and the driven pulley on the side where the belt is sent when the ejector pin is retracted Either of these may be used. Or it may be between driven pulleys. The number of driven pulleys is not limited to two. Further, in FIG. 2, when the driven pulley is positioned at the upper left and lower right of the back of the movable platen, the belt may be pressed downward from above by an idler pulley provided on the swing member. In another case, the belt may be pressed in the horizontal direction. Further, the idler pulley may be toothed to apply tension to the belt from the inside toward the outside. The ejector motor and idler pulley may be provided on the operation panel side.

The ejector device may be disposed on either the fixed platen or the movable platen, and in the case of a vertical injection molding machine, it is often provided on the fixed platen. The power transmission mechanism of the ejector device may be disposed not only on the back surface of the movable platen or fixed platen, but also in a hollow portion or the like inside the platen. The molding machine of the present invention includes an injection molding machine including injection compression molding and the like, a press molding machine, and a metal working molding machine (machine tool). In addition to the ejector device, the power transmission mechanism may be a mold opening / closing device, a mold clamping device, an injection device, or the like.

It is a side view of the power transmission mechanism of the molding machine of this embodiment. It is a front view of the power transmission mechanism of the molding machine of this embodiment. It is an expanded sectional view in the AA line of FIG. It is a front view of the power transmission mechanism of the conventional molding machine. It is a front view of the power transmission mechanism of another conventional molding machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Movable board 19 Servo motor 22 Drive shaft 23 Drive pulley 26 Driven pulley 32 Belt 24 Ball screw 27 Ball nut 28 Ball screw mechanism 33 Belt tension adjustment mechanism 34 Power transmission mechanism 41 Shoulder bolt (support shaft)
42 Swing member 43 Idler pulley 52 Adjuster bolt

Claims (2)

In a power transmission mechanism of a molding machine in which a belt is stretched between a drive pulley and a driven pulley attached to a drive shaft of a motor, and a rotary motion is converted into a linear motion by a ball screw mechanism attached to the driven pulley.
A power transmission mechanism of a molding machine, wherein an idler pulley attached to a swinging member swingable about a support shaft is in contact with the belt. The molding machine is an injection molding machine;
The power transmission mechanism of the molding machine according to claim 1, wherein a power transmission mechanism of an ejector device is provided on the back surface or inside of the movable platen or the fixed platen.

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