JP2009241425A - Injection molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect, beforehand, a state in which the timing belt breaks. <P>SOLUTION: The injection molding machine has an encoder 13 which detects the number of revolutions of the servomotor 12 for mold opening/closing carrying out opening and closing of the mold of the machine in the form of a number x of mold-opening/closing encoder pulses, a rotary encoder 18 detecting the mold-opening stroke S in the form of a number y of mold-opening stroke pulses and an anomaly detecting means 20 of detecting an anomaly of the timing belt 10. When the number x of the mold-opening/closing encoder pulses is directly proportional to the number y of mold-opening stroke pulses, the anomaly detecting means 20 determines the status of the timing belt 10 to be normal. When the constant (a) calculated from the proportional relationship between the number x of the mold-opening/closing encoder pulses and the number y of the mold-opening stroke pulses is out of a predetermined tolerance, the anomaly detecting means 20 determines that there is an anomaly in the timing belt 10, thus allowing, beforehand, grasping of an anomaly that the timing belt 10 breaks. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an injection molding machine that molds a mold by opening and closing a mold, and in particular, when a malfunction occurs in a timing belt that transmits driving force to perform mold opening and closing, the timing belt breaks. The present invention relates to an injection molding machine that can detect whether or not the state of a timing belt is normal.

  As is well known, an injection molding machine is used to form a molded body made of synthetic resin or the like. In such a general injection molding machine, a timing belt and a pulley are frequently used as a driving force transmission means when transmitting a driving force from a driving source such as a motor to a driving transmission mechanism for opening and closing a mold. .

  In Patent Document 1, a timing belt as a driving force transmission unit is wound around an outer peripheral surface of a substantially disk-shaped table configured in an injection molding machine, and the driving pulley is driven to rotate, thereby rotating the driving pulley through the timing belt. A vertical injection molding machine that drives a substantially disk-shaped table is disclosed.

JP 2007-290195 A

  The timing belt configured in the injection molding machine in the background art or the like may wear its surface or transmit excessive driving torque to the timing belt for a long period of time if the injection molding machine continues to operate for a long period of time. As a result, there is a concern that the timing belt may be damaged or that the injection molding machine may malfunction and break down.

  The present invention solves the above-mentioned problems, and when a problem occurs in a drive transmission means such as a timing belt, the injection molding machine can detect the state before the drive transmission means breaks. About.

  An injection molding machine according to claim 1 is an injection molding machine provided with driving force transmission means for transmitting a driving force to a drive transmission mechanism for opening and closing a mold, and the number of rotations of a servo motor for opening and closing the mold. A motor encoder that detects a mold opening / closing encoder pulse number, and a rotary encoder that detects a mold opening stroke from mold closing to mold opening as a mold opening stroke pulse number. When the opening stroke pulse number is in a proportional relationship, it is determined to be normal, while the constant calculated from the proportional relationship between the encoder pulse number and the mold opening stroke pulse number deviates from a predetermined threshold, An abnormality detecting means for determining that the driving force transmitting means is abnormal is provided.

  The injection molding machine according to claim 2 is the injection molding machine according to claim 1, wherein when the abnormality detection unit determines that the driving force transmission unit is abnormal, the abnormality detection unit outputs an abnormality. Drive stop means for stopping the operation of the injection molding machine based on the signal is provided.

  The injection molding machine according to claim 3 is an injection molding machine according to claim 2, wherein when the abnormality detection signal is output from the abnormality detection means, warning means for notifying that the driving force transmission means is abnormal. It is characterized by having.

  According to a fourth aspect of the present invention, in the injection molding machine according to the third aspect, the warning means is a display device for displaying, on the screen, characters or figures that there is an abnormality in the driving force transmission means. It is characterized by that.

  The injection molding machine according to claim 5 is the injection molding machine according to claim 3, wherein the warning means is a voice output means for notifying the abnormality of the driving force transmission means by voice. To do.

  An injection molding machine according to a sixth aspect of the present invention is the injection molding machine according to any one of the first to fifth aspects, wherein the injection molding machine is a vertical injection molding machine that opens and closes a mold in a vertical direction.

  According to the invention of the injection molding machine according to claim 1, an injection molding machine including a driving force transmission means for transmitting a driving force to a drive transmission mechanism for opening and closing the mold, the mold opening and closing servo performing the mold opening and closing. A motor encoder that detects the number of rotations of the motor as the number of encoder pulses for mold opening and closing; and a rotary encoder that detects the number of mold opening strokes from mold closing to mold opening as the number of mold opening stroke pulses. A constant calculated from the proportional relationship between the encoder pulse number and the mold opening stroke pulse number is determined from a predetermined threshold value. When it comes off, it is provided with an abnormality detection means for determining that the driving force transmission means has an abnormality, and is provided with a driving force transmission means such as a timing belt. When the drive transmission mechanism is operated, the relationship between the rotation speed of the mold opening / closing servo motor and the number of mold opening stroke pulses is proportional, but the timing belt as the driving force transmission means is worn or worn. When tooth jumping occurs, the proportional relationship between the number of encoder pulses and the number of mold opening stroke pulses is lost. Since the abnormality detecting means detects that there is an abnormality in the driving force transmission means due to the loss of the proportional relationship, replace the timing belt as the driving force transmission means with a normal one before it breaks. Furthermore, it is possible to prevent the timing belt from being broken and scattered, which is excellent in safety.

  According to the invention of the injection molding machine according to claim 2, in claim 1, when the abnormality detecting means determines that the driving force transmitting means is abnormal, the abnormality detection signal output from the abnormality detecting means. Since the drive stop means for stopping the operation of the injection molding machine is provided based on the above, the operation of the injection molding machine can be stopped urgently before the timing belt as the driving force transmission means is cut due to wear or the like. , It can be avoided that the injection molding machine malfunctions due to the timing belt cutting, and it can be avoided that the timing belt breaks and scatters. Excellent.

  According to the invention of the injection molding machine according to claim 3, in claim 2, when an abnormality detection signal is output from the abnormality detection means, a warning means for notifying that there is an abnormality in the driving force transmission means is provided. Therefore, an operator who operates the injection molding machine or the like can grasp that there is an abnormality in the timing belt as a driving force transmission means before the timing belt breaks.

  According to an invention of an injection molding machine according to a fourth aspect, in the third aspect, the warning means is a display device that displays, on the screen, characters or figures that there is an abnormality in the driving force transmission means. As a result, the fact that there is an abnormality in the driving force transmission means is displayed as a warning on the screen of the display device with characters and figures, so the operator can grasp at a glance that an abnormality has occurred in the driving force transmission means Can do.

  According to the invention of the injection molding machine according to claim 5, in claim 3, the warning means is a voice output means for notifying that there is an abnormality in the driving force transmission means, so that the driving force transmission means Can hear and know that an abnormality has occurred.

  An injection molding machine according to a sixth aspect is the vertical injection molding machine according to any one of the first to fifth aspects, wherein the injection molding machine is a vertical injection molding machine and opens and closes a mold in a vertical direction. Even so, the effects described above can be achieved.

  Hereinafter, an embodiment as the best mode for carrying out the present invention will be described with reference to FIGS. Needless to say, the present invention can be easily applied to configurations other than those described in the embodiments without departing from the spirit of the invention.

  1 and 2 are front views showing a mold clamping unit of a vertical injection molding machine. FIG. 1 shows a state in which the mold is closed, and FIG. 2 shows a state in which the mold is opened. The vertical injection molding machine according to the present invention is roughly composed of the mold clamping unit 1 and an injection unit (not shown).

  As shown in FIGS. 1 and 2, the mold clamping unit 1 is a fixed die plate 3 to which a fixed die 2 is fixed, a movable die that is provided above the fixed die 2 and is moved in the vertical direction together with the tie bar 4. The fixed movable die plate 6 of 5 is expanded and contracted to move the movable die 5 provided on the lower side of the movable die plate 6 along the longitudinal direction of the tie bar 4 through the movable die plate 6, A toggle link mechanism 7 that opens and closes the fixed mold 2, a ball screw unit 9 that transmits driving force to a crosshead 8 that is configured in the toggle link mechanism 7, and a first timing belt 10 that transmits power to the ball screw unit 9. And a mold opening / closing servomotor 12 as a driving source for opening and closing the mold by operating the toggle link mechanism 7 via the pulley 11, the ball screw unit 9 and the like. The encoder 13 for the motor that detects the rotation speed of the rotor 12 as “the number of encoder pulses for opening / closing the mold (x)”, and the molded body attached to the cavity of the fixed mold 2 are passed through the second timing belt 15 and the pulley 16a. The ejection servo motor 16 as a drive source for ejecting and ejecting the eject pin 19, the tail stock 17 provided below the toggle link mechanism 7, and the tail stock 17 are attached to the mold opening stroke S from mold closing to mold opening. A rotary encoder 18 or the like that detects the number of mold opening stroke pulses (y) based on the stroke S1 of the crosshead 8 is provided. The columnar tie bar 4 installed on the movable die plate 6 and the tail stock 17 is inserted into the fixed die plate 6 fixed to the machine base (not shown), and the movable die plate 6 and the tail stock 17 are inserted. Is provided so as to be vertically movable together with the tie bar 4. Further, the tail stock 17 is connected to the fixed die plate 6 by the toggle link mechanism 7, and when the tail stock 17 is moved up and down by the expansion and contraction of the toggle link mechanism 7 accompanying the drive of the mold opening / closing servo motor 12, The movable die plate 6 connected by the tail stock 17 and the tie bar 4 is moved up and down to open and close the mold.

  The vertical injection molding machine constituting the mold clamping unit 1 calculates the constant a described later from the “number of encoder pulses for opening / closing the mold (x)” and “number of mold opening stroke pulses (y)”. An abnormality detection means 20 for detecting an abnormality of one timing belt 10, a drive stop means 21 for urgently stopping the operation of the vertical injection molding machine based on an abnormality detection signal output from the abnormality detection means 20, and a first timing belt 10 includes an audio output means 22 and a display device 23 as warning means for notifying that there is an abnormality.

  Here, the operation of the mold clamping unit of the vertical injection molding machine, which is the main part of the present invention, will be described. In the state where the toggle link mechanism 7 shown in FIG. 1 extends in the vertical direction and is closed by a mold, molten resin is injected from an injection nozzle of an injection unit (not shown) into a cavity formed by the fixed mold 2 and the movable mold 5. Then, the injected molten resin is filled in the cavity.

  Next, when the mold opening / closing servo motor 12 is rotationally driven, a driving force is transmitted to the ball screw unit 9 via the pulley 11 and the first timing belt 10, and the ball screw shaft 9 b configured in the ball screw unit 9 is transmitted. Is rotated, the ball screw nut 9a of the ball screw unit 9 screwed with the ball screw shaft 9b and attached to the tail stock 17 is raised, and the toggle link mechanism 7 is bent and contracted accordingly, thereby the tail stock. 17 is raised. Then, in conjunction with this, the movable die plate 6 and the tie bar 4 are raised to open the movable die 5 with respect to the fixed die 2 (the state shown in FIG. 2).

  Subsequently, when the eject servomotor 16 is driven and the eject pin 19 is advanced via the second timing belt 15, the pulley 16 a, and the like, the molded product attached to the fixed mold 2 is discharged. And a molded object is manufactured one after another by repeating such a series of operations as one cycle.

  Here, when the mold clamping unit 1 is repeatedly operated, the first mold opening / closing servo motor 12 is operated based on the “number of mold opening / closing encoder pulses (x)” and “number of mold opening stroke pulses (y)”. An example of an operation for detecting an abnormality of one timing belt 10 will be described below with reference to FIGS.

  First, when the mold clamping unit 1 is continuously driven along with the operation of the vertical injection molding machine, the rotary encoder 18 detects the “number of mold opening stroke pulses (y)” based on the stroke S of the crosshead 8. . At the same time, the motor encoder 13 detects the number of rotations of the mold opening / closing servomotor 12 as “number of mold opening / closing encoder pulses (x)”. The relationship between the “number of mold opening stroke pulses (y)” and “number of mold opening / closing encoder pulses (x)” is shown in FIG. 3 and FIG. When the mold clamping unit 1 is in normal operation, “the mold opening stroke pulse number (y)” and “the mold opening / closing encoder” are plotted on the horizontal axis as “the number of encoder pulses for opening / closing the mold (x)”. Since the “number of pulses (x)” has a direct proportional relationship, a linear graph is obtained. On the other hand, when the first timing belt 10 has an abnormality such as breakage, wear, or so-called tooth skipping, the graph is displayed so as to be bent at an “abnormal point” as shown in FIG. The direct proportional relationship between the “number of encoder pulses for opening / closing the mold (x)” and the “number of mold opening stroke pulses (y)” is out of the allowable range because the constant “a” deviates from a predetermined threshold value. Therefore, the linear graph when the first timing belt 10 shown in FIG. 3 is normal changes at the “abnormality occurrence point z” and is not linear (the state shown in FIG. 4). When the constant a changes to a value other than the predetermined threshold, based on the change, the abnormality detection means 20 determines that the first timing belt 10 is abnormal, and the abnormality detection means 20 On the basis of the abnormality detection signal output from, the drive stopping means 21 urgently stops the operation of the vertical injection molding machine by turning off the power supplied to the vertical injection molding machine. Further, the abnormality detection signal output from the abnormality detection means 20 is simultaneously output to the display device 23 and the audio output means 22 as warning means, and there is an abnormality in the first timing belt 10 on the screen of the display device 23. The voice output means 22 outputs a voice indicating that an abnormality has occurred in the first timing belt 10.

  As described above, the vertical injection molding machine according to the present invention includes a motor encoder 13 that detects the number of rotations of the mold opening / closing servo motor 12 that performs mold opening / closing as “the number of encoder pulses for opening / closing the mold (x)”, and the mold closing. And a rotary encoder 18 that detects the “mold opening stroke S” from the mold opening to the mold opening as the “number of mold opening stroke pulses (y)”, and the “number of encoder pulses (x) of mold opening / closing” of the rotary encoder 18 and the motor When the “number of mold opening stroke pulses (y)” of the encoder is in a direct proportional relationship, the abnormality detection means 20 determines that the state of the first timing belt 10 as the driving force transmission means is normal, while “ The constant a (excluding 0) calculated from the direct proportional relationship between the “number of mold opening / closing encoder pulses (x)” and the “number of mold opening stroke pulses (y)” deviates from a predetermined threshold. , Those having the abnormality detecting means 20 determines that there is an abnormality in the first timing belt 10. Thus, when the toggle link mechanism 7 as a drive transmission mechanism used for opening and closing the mold is operated via the driving force transmission means such as the first timing belt 10, the rotational speed of the mold opening and closing servomotor The relationship between the “number of mold opening / closing encoder pulses (x)” and the “number of mold opening stroke pulses (y)” is proportional because the constant “a” is within a predetermined threshold range. When the first timing belt 10 or the like is worn or has tooth skipping due to wear, the proportional relationship between the “number of encoder pulses for opening / closing the mold (x)” and the “number of mold opening stroke pulses (y)” is a constant a Deviates from the predetermined threshold value and falls outside the allowable range, and based on this value, the abnormality detection means 20 detects (discriminates) that there is an abnormality in the first timing belt 10, so the first tie as the driving force transmission means It is possible to replace the first timing belt 10 with a normal one before the belt 10 breaks, and to prevent the timing belt 10 from being cut and scattered. Is possible, so it is excellent in safety.

  Further, when the abnormality detection means 20 determines that there is an abnormality in the first timing belt 10, the vertical injection molding machine operates the injection molding machine based on the abnormality detection signal output from the abnormality detection means 20. Since the drive stop means 21 for stopping is provided, the operation of the vertical injection molding machine can be urgently stopped before the first timing belt 10 as the drive force transmission means is cut due to wear or the like. Thereby, it is possible to avoid the vertical injection molding machine from malfunctioning due to the cutting of the first timing belt 10, and thus excellent in safety.

  Further, when an abnormality detection signal is output from the abnormality detection means 20, a display device 23 is provided in the vertical injection molding machine as warning means for notifying that there is an abnormality in the first timing belt 10 which is a driving force transmission means. Therefore, the operator can quickly confirm that an abnormality has occurred in the first timing belt 10 simply by glancing at the screen on which characters and figures indicate that the first timing belt 10 is abnormal. I can grasp it.

  In addition to the display device 23, the warning means also includes voice output means 22 that constitutes a speaker that informs by voice, so that the operator can output a voice that an abnormality has occurred in the first timing belt 10. By outputting by means 22, the state of first timing belt 10 can be heard and known.

  As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above-described embodiment, an abnormality in the first timing belt 10 that transmits the driving force for opening and closing the mold is detected. However, the present invention is not particularly limited thereto, and means for transmitting the driving force is used. If it exists, it may be used for other purposes.

It is a front view of the principal part which shows the state which the mold open of the vertical injection molding machine of an example of this invention. It is a front view of the principal part which shows the closed state of a vertical injection molding machine same as the above. FIG. 6 is a graph showing the relationship between “number of mold opening stroke pulses” and “number of mold opening / closing encoder pulses” during normal operation of a vertical injection molding machine. It is a graph which shows the state which abnormality generate | occur | produced in the 1st timing belt at the time of normal operation | movement of a vertical injection molding machine same as the above.

Explanation of symbols

7 Toggle link mechanism (drive transmission mechanism)
10 Timing belt (drive force transmission means)
12 servo motor for opening and closing 13 motor encoder 18 rotary encoder 20 error detection means 22 audio output means 23 display device (warning means a constant x number of encoder pulses for type opening and closing y number of opening stroke pulses

Claims (6)

An injection molding machine comprising a driving force transmission means for transmitting a driving force to a drive transmission mechanism for opening and closing a mold,
A motor encoder for detecting the number of rotations of a mold opening / closing servomotor for performing mold opening / closing as the number of encoder pulses for mold opening / closing;
Equipped with a rotary encoder that detects the mold opening stroke from mold closing to mold opening as the number of mold opening stroke pulses,
When the number of encoder pulses for opening and closing the mold and the number of mold opening stroke pulses are in a proportional relationship, it is determined as normal, and is calculated from the proportional relationship between the number of encoder pulses and the number of mold opening stroke pulses. An injection molding machine comprising an abnormality detecting means for determining that the driving force transmitting means is abnormal when the constant deviates from a predetermined threshold value.   When the abnormality detection unit determines that the driving force transmission unit has an abnormality, a drive stop unit is provided to stop the operation of the injection molding machine based on an abnormality detection signal output from the abnormality detection unit. The injection molding machine according to claim 1, characterized in that:   The injection molding machine according to claim 2, further comprising warning means for notifying that there is an abnormality in the driving force transmission means when an abnormality detection signal is output from the abnormality detection means.   4. The injection molding machine according to claim 3, wherein the warning means is a display device that displays, on the screen, characters or figures that indicate an abnormality in the driving force transmission means.   The injection molding machine according to claim 3, wherein the warning means is an audio output means for notifying the driving force transmission means that there is an abnormality.   6. The injection molding machine according to claim 1, wherein the injection molding machine is a vertical injection molding machine that opens and closes a mold in a vertical direction.

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