Nissei Plastic Industrial Co., Ltd.

Fumio Shiozawa

Toshimi Kato

Masaaki Minamimura

Takashi Hakoda

Tetsuo Ikeda

Hidenobu Yoda

Kiyoto Takizawa

Nobuyuki Nakamura

Michiaki Takizawa

Yuji Hayashi

Yoshitoshi Yamagiwa

Haruo Okada

Takashi Magario

Minoru Yamazaki

Kazuki Miyairi

Masahiko Miyajima

Makoto Takeuchi

Masatake Hoshina

Yoshito Aruga

Keizou Shimizu

Seiichi Sakurada

A measurement control method uses an ending target position Xes calculated by adding a prescribed length Ls to a measurement ending position Xe. A rotation rate pattern Ar for rotating a screw, a back pressure Ps in relation to the screw, and a retraction rate pattern Ab for the screwto retract, are set in advance. The remaining rotation rate pattern Ar to stop the rotation of the screwat the ending target position Xes from the detected screw position X, is calculated at the time of measurement, and the rotation of the screwis stopped based on the calculation. Further, the remaining retraction rate pattern Ab is calculated from the detected retraction rate Vd, and the retraction of the screwis stopped based on the calculation. The result is the stopping of the screw at the measurement ending position Xe.

Measurement control method of an injection molding machine

An ending target position Xes corresponding to the measurement ending position Xe, a rotation rate pattern Ar to rotate a screw, and a hypothetical retraction rate pattern Ab for the screwto retract are set in advance, the remaining rotation rate pattern Ar to stop the screwrotation at the ending target position Xes is predicated by calculation based on the screw position X detected at every specified time interval Ts at the time of measurement, based on which the screwis controlled to rotate to the measurement ending position Xe, the remaining retraction rate pattern Ab to stop the screwretraction at the ending target position Xe based on the screwretraction rate Vd detected at every specified time interval Ts, based on which the screwis controlled to retract to the measurement ending position Xe, the rotation and retraction of the screware stopped, and subsequently the screwis controlled to reverse rotate by a pre-set constant amount of rotation Rc while position controlling its position to the measurement ending position Xe.

Leak of a metered resin by backflow in injection filling is prevented not depending on reverse rotation of a screw but by closing a ring valve by controlling a screw forward movement speed in injection filling. An injection filling speed and a valve closing operation speed are set to the screw forward movement speed. The valve closing operation speed is different from an initial speed of the injection filling speed, and the operation time thereof is set to the time necessary for moving the injection screw by a distance capable of performing the valve closing after the end of metering. The valve closing is performed with the set operation speed and the set operation time.

Method for preventing backflow of resin in injection apparatus

The purpose of the invention is to prevent a sticking of lubricant to a ball screw shaft and a scattering to the circumstance in an electromotive toggle mold clamping device. This invention relates to the electric motor driven toggle mold clamping device wherein a ball nut member is screwed together to the ball screw shaft which rotates by an electric motor to advance and retreat freely and a cross head is fixed to the ball nut member, a cylindrical or polygonal cylindrical member which has a cylindrical body shape or square cylindrical body shape with a length and a size of placing the ball screw shaft with a required gap while retreating the cross head, is attached to the front ends of the cross head concentrically with the ball screw shaft. The ball screw shaft protruding from the cross head is placed in the cylindrical or polygonal cylindrical member having a required gap.

Electric motor driven toggle mold clamping device

An injection molding machine equipped with an assembly for vibration processing which efficiently performs processing operations on the resin in the mold with vibration overcomes the restriction of vibration frequency due to the limited response of return springs and due to vibration transfer loss from the vibratory rods to the vibratory plate when operating at a high frequency. The injection molding machine performs both vibration and ejection without an ejector plate by making the vibratory plate serve a dual purpose and thus enable reduction in both mold size and production cost.

Injection molding machine having assembly for vibration processing

A method and an apparatus for injection-molding a molten resin wherein any flaw such as warpage, shrinkage or the like does not occur in products having a small thickness when the desired product of injection molded resin is molded by injecting the molten resin into a cavity of an injection molding die. The molten resin is injected into the cavity under proper control with respect to injection speed and pressure, the pressure of the molten resin being temporarily set and reduced to a preset reference value when the cavity is filled with the molten resin, and subsequently, the pressure of the molten resin filled in the cavity is released.

Injection molding method and apparatus

A penetration hole of plasticized resin is pierced in a screw head, so that the resin may be accumulated in uniform temperature distribution without sacrificing the function of the injection screw. More specifically, a penetration hole 15 of plasticized resin is pierced inside a screw head 13 at the front end of a screw 12 from the front middle to the rear periphery so as to communicate between the screw peripheral parts and the screw head front space. A ring valve 17 for opening and closing a rear opening 15a of the penetration hole 15, and closing the gap around the screw head is fitted to the rear periphery of the screw head 13 so as to be free to move back and forth.

Injection screw

A method of setting molding conditions for an injection molding machine 1 using a mold 2 whose specifications data are unclear included three setting processes. In the first setting process A, by inputting known data into controller 3, the molding conditions based on a data base prepared in advance and said input known data are set. In the second setting process B, injection molding is performed according to prescribed molding conditions pre-selected concerning injection pressure P, injection speed V and the injection start position of screw 4, and then, based on the product just molded, injection pressure P is altered, to set said altered injection pressure P, injection speed V and proper pre-feed measurement value Md as molding conditions. In the third setting process C, injection molding is performed according to molding conditions obtained from said second setting process B, and subsequently, taking into account the findings from the product just molded, said molding conditions are adjusted. In this manner, even an unskilled operator is allowed to undertake setting molding conditions reliably and with great ease for an injection molding machine loaded with a set of molds whose specifications data are unclear.

Method of setting molding conditions for an injection molding machine

An injection molding method characterized in that after resin charging is completed, with the screw allowed to rotate, process is shifted to the metering process, and using the back pressure in the metering process as a dwelling pressure, dwelling is performed simultaneously with the resin metering. In addition, with the back pressure required for metering set to a higher value as a primary back pressure, and using the back pressure as a dwelling pressure, dwelling is performed simultaneously with the resin metering, and after the dwelling time has elapsed, with the pressure allowed to lower so as to use as a secondary back pressure, the metering is continued to a set time. According to the above-mentioned method, as a whole, the required cycle time becomes shorter than in a conventional case where metering is started after dwelling.

Injection molding method

An improved injection molding method comprising, tightening an injection molding die with a die tightening force lower than that corresponding to a conventionally rated pressure, injecting a molten resin in a die cavity with an injection molding pressure of which intensity is determined corresponding to the die tightening force so that a gap is formed so as to permit only gas to flow outside of the die cavity via the gap, after completion of injecting temporarily interrupting injection molding so as to release a part of the injection molding pressure from the die cavity so as to maintain the reduced injection molding pressure in the die cavity in the uniformalized state, and raising the die tightening force up to a level corresponding to the rated pressure, and moreover, raising the injection molding pressure in the die cavity. Since a molten resin is injected in the die cavity with a low intensity of injection molding pressure with a low corresponding die tightening force, and moreover, the injection molding pressure is held in the die cavity in the uniformalized state before it is retained in the die cavity, a molded article having a small thickness and a large projected area can easily be produced without any occurrence of a malfunction such as warpage or the like.

Growing community of inventors

Nagano-ken, Japan

Fumio Shiozawa