Injection apparatus and molding machine

Patent metadata

Field	Value
Publication number	US-10105754-B2
Application number	US-201715422639-A
Country	US
Kind code	B2
Filing date	Feb 2, 2017
Priority date	Apr 5, 2016
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A flow rate control valve configuring a meter-out circuit of an injection cylinder is an overlap type where a first port starts to be opened by a spool passing through an overlapping range. The control device holds a characteristic table linking a command value of a control command to the flow rate control valve and a velocity of a plunger including also the movement of the plunger which occurs due to a gap flow even if the spool is located in the overlapping range. Further, the control device specifies the command value corresponding to the target velocity set by operation of the input device based on the characteristic table, performs open control based on this command value, then performs the feedback control for realizing the target velocity.

First claim

The invention claimed is:

1. An injection apparatus comprising:
an injection cylinder connected to a plunger capable of sliding in a sleeve communicated with an inside of a mold,
a flow rate control valve which configures a meter-in circuit or meter-out circuit of the injection cylinder,
a sensor which detects at least one of a position or a velocity of the plunger,
an input device which accepts an operation of a user, and
a control device which controls the flow rate control valve, wherein
the flow rate control valve comprises a valve main body comprising a port and a valve body sliding with respect to the valve main body, where the valve body is positioned at a position in accordance with a command value of an input control command, the port is closed as it is at a time when the valve body is positioned in a predetermined overlapping range even if the valve body moves, the port starts to be opened by the valve body passing through the overlapping range, and a gap flow where hydraulic fluid flows through a gap between the valve main body and the valve body to the port regardless of whether the valve body is positioned in the overlapping range, and
the control device comprises
a memory unit which holds characteristic information linking the command value of the control command to the flow rate control valve and the velocity of the plunger including a movement of the plunger which is caused by the gap flow regardless of whether the valve body is positioned in the overlapping range,
a target velocity setting part for setting a target velocity of the plunger based on operation of the input device,
a command value setting part which sets the command value of the control command for open control of the flow rate control valve at the time of start of injection by specifying the command value of the control command to the flow rate control valve corresponding to the target velocity set by the target velocity setting part based on the characteristic information,
an open control part which outputs a control command having a command value set by the command value setting part and performs open control, and
a feedback control part which performs feedback control of the flow rate control valve so that the target velocity set by the target velocity setting part is realized based on a detection value of the sensor after the open control.

2. The injection apparatus according to claim 1 , wherein the control device further comprises an information updating part which updates the characteristic information based on the command value of the control command and the velocity detected by the sensor at the time when the control command is output to the flow rate control valve.

3. The injection apparatus according to claim 2 , wherein
the characteristic information is a table linking a predetermined plurality of command values and a plurality of velocities of the plunger,
the control device further comprises an update-use control part which, separately from the molding cycle, outputs the control commands of the predetermined plurality of command values in order, and
the information updating part updates the velocities linked with the predetermined plurality of command values in the table according to the velocity detected by the sensor at the time when the control commands having the predetermined plurality of command values are output in order from the update-use control part.

4. The injection apparatus according to claim 2 , wherein the information updating part updates the characteristic information based on the command value of the control command and the velocity detected by the sensor at the time when this control command is output to the flow rate control valve in the molding cycle.

5. The injection apparatus according to claim 1 , wherein
the sensor is able to detect the position of the plunger,
the control device comprises a target position calculation part which calculates the target position of the plunger for each elapsed time based on the target velocity set by the target velocity setting part, and
the feedback control part
calculates the command value for each elapsed time based on a sum of a value proportional to a deviation between the position of the plunger detected by the sensor at that time and the target position of the plunger at that time and the predetermined offset value and
uses the last command value in the open control as the offset value.

6. The injection apparatus according to claim 1 , further comprising a display device capable of displaying an image, wherein
the sensor detects the position of the plunger,
the command value setting part sets the command value of the control command for the open control with respect to the elapsed time from the start of injection,
the open control part outputs the control command of the command value set by the command value setting part based on the elapsed time from the start of injection, and
the control device comprises a display control part which makes the display device display a predetermined alert image at the time when a difference between the position of the plunger at the time of end of the open control which is calculated based on the target velocity set by the target velocity setting part and the position of the plunger detected by the sensor at the time of end of the open control exceeds a predetermined threshold value.

7. The injection apparatus according to claim 1 , wherein
the open control part and the feedback control part control the flow rate control valve so as to switch from the open control to the feedback control at the time when the velocity of the plunger reaches a constant level in a case where the target velocity of the plunger set by the target velocity setting part rises to the constant velocity from the start of injection, then the constant velocity is maintained.

8. A molding machine having an injection apparatus according to claim 1 .

Assignees

• Toshiba Machine Co Ltd

Inventors

• Yokoyama Hiroshi
• Takekawa Shunsuke

Classifications

• B29C2945/76595

  Velocity · CPC title

• B29C2045/7606

  Controlling or regulating the display unit · CPC title

• B29C2945/76545

  Flow rate · CPC title

• B22D17/32 Primary

  Controlling equipment · CPC title

• B22D17/10

  with horizontal press motion · CPC title