Fanuc Corporation

Satoshi Takatsugi

Junpei Maruyama

Wataru Shiraishi

Tatsuhiro Uchiyama

Toshio Ishikuro

Hiroyasu Asaoka

Hiroshi Watanabe

Hiroshi Imamura

Akira Oomori

Susumu Ito

Koichi Nishimura

Osamu Saito

Masatoshi Senga

Ryousuke Mori

Tatsuya Kawasaki

Toshio Ishiguro

Wataru Shirashi

A display system includes: an imaging unit that images a mold from below; and a display unit that displays an image taken by the imaging unit together with a carry-in range of the mold in order to transport the mold in place between the stationary platen and the moving platen.

Display system and display method

An injection molding system is configured to produce a multi-color molded article by simultaneously or sequentially injection-molding resins of a plurality of types by means of a plurality of injection molding machines. An insert mold is mounted in a mold of a first injection molding machine and a primary molded article is molded by this injection molding machine. Thereafter, a robot arm takes out the insert mold, along with the primary molded article, from the mold of the injection molding machine and attaches it to a mold of a second injection molding machine. A two-color molded article is injection-molded by the second injection molding machine and removed as a product.

Manufacturing method and injection molding system for multi-color molded article

An adaptor plate is provided between a platen and a mold to measure a temperature of each of divided regions obtained by dividing the adaptor plate into a plurality of regions and adjust a temperature for each of the regions. By doing so, it is possible to adjust the temperature at points closer to the center of the mold than tie bars. Further, by adjusting the temperature of the adaptor plate provided between the platen and the mold, it is possible to precisely adjust a tie bar balance and a platen parallelism even during molding.

Clamping device of injection molding machine

In a mold clamping mechanism for an injection molding machine, a mold platen stiffness adjusting plate is attached to a mold platen (a movable platen, a fixed platen) at the mold attachment surface thereof. The mold platen stiffness adjusting plate is provided, at the mold attachment surface thereof, with elements for mold attachment that have the same shapes and are arranged on the same places as those provided on the mold platen at the mold attachment surface thereof. Accordingly, the same mold can be attached to the mold platen stiffness adjusting plate attached to the mold platen, and can also be attached to the mold platen from which the mold platen stiffness adjusting plate is detached.

Mold clamping mechanism for injection molding machine

Torques and resin pressures applied to a screw are detected during the forward movement of the screw and coefficients of correlation between the detected torques and resin pressures are calculated. When the check ring is open, the flight of the screw receives resin pressure, and the screw torque increases proportionally to the resin pressure due to resin backflow, so the coefficients of correlation between the screw torques and the resin pressures are higher than a reference value. When the check ring closes, the flight of the screw no longer receive resin pressure, so the screw torque decreases and the coefficients of correlation become lower than the reference value. The check ring is determined to be closed when the coefficients of correlation become lower than the reference value.

Injection molding machine and method for determining closure of check ring

An injection molding machine capable of accurately detecting a rotational force exerted on a screw by resin backflow to easily evaluate states of resin backflow and closure of a check valve. In a state where the screw is stopped axially and rotationally after metering is finished, a load exerted on the screw in the rotational direction is detected. This load is a rotational force exerted on the screw from resin remaining between flights of the screw (resistance torque component). During injection, a load T exerted on the screw in the direction of rotation is detected, and the resistance torque component is subtracted from the detected load T to obtain a backflow torque component generated by resin flowing back through the check valve. By simultaneously displaying waveforms of backflow torque components in a plurality of molding cycles to be overlapped, stability of closure of the check valve is readily evaluated.

Injection molding machine

Screw rotation speeds and screw rotating torques are measured at predetermined time intervals during metering and substituted into a previously-assumed function to determine a maximum screw rotating torque at each screw rotation speed. An allowable upper limit of screw rotating torque is set for each screw rotation speed on the basis of the determined maximum screw rotating torque. If a screw rotating torque exceeding the allowable upper limit is detected during metering after the allowable upper limit is set, the screw rotation is stopped or changed.

Injection molding machine having function for monitoring screw rotating torques

An injection molding machine estimates a check valve wear amount, making it possible to predict a check valve use limit. At start of injection, the check valve is at a position advanced a stroke Swith respect to a screw position (a position of a check seat that contacts the check valve and closes a resin flow channel). As the screw advances, the check valve retreats and closes when the screw moves a distance X. When the check valve is worn &#x394;S (S=S+&#x394;S), it closes when the screw moves X. Since the check valve stroke and the distance the screw moves until the check valve closes are proportional, S/X=S/X=a. Therefore, &#x394;S=aX&#x2212;S, and the wear amount &#x394;S can be obtained by detecting the check valve closing position Xand using this position Xand the known stroke S. The closing position is detected from the peak value of rotational force acting on the screw. Once the wear amount is obtained, the check valve use limit can be predicted from an allowable value of wear.

Injection molding machine having a check valve closing position determining device

When a screw equipped with a check ring is moved forward, torque acting on the screw is detected, and whether the check ring is closed is determined on the basis of the detected torque. The screw is rotated in reverse when the check ring is determined not to be closed, and the reverse rotation of the screw is stopped when the check ring is determined to be closed. The reverse rotation of the screw is thereby controlled so that the screw is rotated in reverse by an optimal amount for reliably closing the check ring.

Injecting molding machine having a torque detecting device

A mold is mounted with a locating ring mated into a hole in a stationary platen. A distance measuring unit is disposed to the side of the injection nozzle. The distance A between the sprue hole and the outer circumference of the locating ring and the distance B between the distance measuring unit and the outer circumference of the locating ring are both known. The distance C between the central axis of the nozzle hole and the side of the injection nozzle is also known. If the distance D to the side of the injection nozzle is measured by means of the distance measuring unit, the displacement between the central axis of the sprue hole and the central axis of the nozzle hole is obtained by calculating {(A+B)&#x2212;(C+D)}. The injection nozzle is centered by being moved manually or automatically by the amount corresponding to the displacement.

Injection molding machine having a centering device for centering a nozzle hole

When the screw moves forward, resin backflow occurs. The backflow acts on the screw, applying torque to the screw. During forward movement of the screw, screw torque is produced as shown in FIG.A if the check ring is not worn, or as shown in FIG.B if the check ring is worn, because wear increases the backflow and delays the closure of the check ring. The magnitude of the peak screw torque and the associated time and screw position vary depending on the presence or absence of wear, so wear of the check ring is estimated from variations in these physical quantities. The state of wear of the check ring, screw head, check seat, and other parts inside the barrel can be estimated.

Injection molding machine having a screw equipped with a check ring

If a screw is moved forward after a metering step is completed, the screw moves in a state where a check ring on a tip end of the screw is in open state. Resin flows in a direction opposite to the injection direction. A rotational force is applied to the screw due to the backflow of the resin. If the check ring closes a resin passage, the rotational force acting on the screw is reduced. A peak time of the screw rotational force is detected as closing point in time of the check ring. Physical amounts such as a screw rotational force and a screw position at that timing are detected. Since the closing point in time of the check ring is precisely detected, correction of the injection/hold pressure switching position and the injection speed switching position can be adjusted more precisely. It is possible to precisely determine whether a molded article is non-defective or defective based on the detected physical amount.

Injection molding machine having a force peak time detecting device

While a check ring of a screw of an injection molding machine is in open state, an absolute value (|&#x394; resin pressure/&#x394; rotation amount|) of a variation of a resin pressure per unit variation of the screw reverse rotation becomes greater than a predetermined reference value. However, after the check ring is closed, |&#x394; resin pressure/&#x394; rotation amount| becomes equal to or less than the reference value. From this, detecting if the |&#x394; resin pressure/&#x394; rotation amount| during reverse rotation of the screw, it is possible to determine that the check ring is closed or not. As a result, it is possible to obtain a screw reverse rotation amount which is optimal for reliably closing the check ring.

Injection molding machine which carries out controlling of closing operation of a check ring

In an injection molding machine capable of appropriately adjusting a control condition for a reverse rotation of a screw and a method for adjusting the control condition, molding is repeated with an amount of a reverse rotation of the screw performed after completion of metering and before injection to be varied in each molding cycle. In injection, resin flows backward until a check valve becomes closed. A peak value of a rotational force causing reverse rotation of the screw by the back flow of resin and other physical amounts are detected as indices of resin back-flow amount. An evaluation value of the control condition is obtained by inputting the indices of resin back-flow amount, metering time, etc. into an evaluation function. The value of screw reverse rotation amount with which the highest evaluation value is obtained is set for the screw reverse rotation.

Injection molding machine and method of adjusting control condition for reverse rotation of screw in injection molding machine

When a resin passage of a check ring is opened, resin backflow occurs during time when an injection screw is moved forward, and a reverse rotational force is applied to the screw by resin backflow. On the other hand, when the resin passage is closed, there is no resin backflow and the reverse rotational force applied to the screw is greatly reduced. Consequently, after completion of metering process and before injection process, the screw is moved forward after the screw has been rotated in reverse a predetermined amount to prevent resin backflow. At this time, a maximum value of the reverse rotational force applied to the screw is detected. Until the detected maximum reverse rotational force reaches a reference value or less, the reverse rotation amount is increased sequentially and respective molding cycles are carried out. When the detected maximum reverse rotational force reaches the reference value or less (passage closure), the reverse rotation amount at this time is set as the reverse rotation amount for the reverse rotation process. By means of this operation, an optimal reverse rotation amount can be adjusted automatically.

Growing community of inventors

Yamanashi, Japan

Satoshi Takatsugi