JPH05111935A - Inspection system in injection molding machine - Google Patents

Abstract

PURPOSE:To easily and surely detect deterioration which may cause trouble in operation of an injection molding machine and injection molding work. CONSTITUTION:The allowable value of driving current and injection pressure is set on the basis of both the driving current of a servomotor necessary at a time for driving the respective parts of an injection molding machine in the decided conditions and injection pressure at a time for performing injection activation in the decided conditions. Further, this allowable value is previously stored in an ROM 117. The respective parts of the injection molding machine are driven in the decided conditions at a time of periodic inspection to detect the driving current of the servometors of the respective shafts and injection pressure. Presence of deterioration of the respective parts of a mechanism is decided by detecting the change in driving resistance of the respective parts of the mechanism by whether the value of driving current of the respective shafts and injection pressure is present in a range of allowable value. The decided result is indicated in a CRT/MDI 119. Since the deterioration state of the respective parts is easily known, it is eliminated that time is consumed in unnecessary maintenance and reregulation work and also abnormality found out at a time of inspection is overlooked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved inspection system for injection molding machines.

[0002]

2. Description of the Related Art A drive system such as a mold clamping mechanism and an injection mechanism in an injection molding machine is subject to periodical changes at predetermined intervals because of volatilization of lubricating oil, changes in properties, and wear and loss of mechanical elements. It is necessary to check the deterioration state of each part by inspection and perform greasing and readjustment work. In conventional regular inspection work, an operator refers to a manual such as a regular inspection manual to perform maintenance such as grease up at predetermined intervals, and by checking the tension of the timing belt using various gauges, The readjustment work was performed as needed.

[0003]

However, the period during which the periodic inspection should be carried out varies depending on the operating conditions of the injection molding machine and the service life of the lubricating oil. Regular inspections are not always performed at appropriate times, and unnecessary grease-up work and readjustment work may be performed to waste time.
In addition, it is troublesome to determine whether the readjustment work is necessary or not by using gauges.On the other hand, when the necessity of the readjustment work is determined based on the visual observation of the appearance, the determination result is uncertain, and the injection molding machine Even if there was deterioration that hinders the operation and injection molding work, this may be overlooked, and the necessary readjustment work may not be performed.

Therefore, an object of the present invention is to solve the above-mentioned drawbacks of the prior art and to easily and surely detect deterioration that may interfere with the operation of the injection molding machine or the injection molding work, and perform necessary maintenance and readjustment. It is an object of the present invention to provide an inspection system for an injection molding machine that can perform work and that does not waste time by performing substantially unnecessary maintenance or readjustment work.

[0005]

According to the inspection system of an injection molding machine of the present invention, a physical quantity that changes when the injection molding machine is driven is allowed for the physical quantity when the injection molding machine is driven under a predetermined condition. A value is set in advance, and when the injection molding machine is inspected, the injection molding machine is driven under the predetermined conditions to detect the physical quantity, and the detected physical quantity is within the predetermined allowable value range. The above object was achieved by determining the deterioration state of each part of the injection molding machine depending on whether or not.

Further, the drive current and injection pressure of the motor are used as physical quantities, and the allowable value is set based on the drive current and injection pressure of the motor when the injection molding machine is driven at the time of shipment.

[0007]

[Function] The allowable value of the physical quantity when the injection molding machine is driven under predetermined conditions with respect to the physical quantity that changes when the injection molding machine is driven in the shipping state in which each part of the injection molding machine is not deteriorated Is set in advance. At the time of inspection of the injection molding machine, the injection molding machine is driven under the predetermined conditions to detect the physical quantity, and the physical quantity of each part of the injection molding machine depends on whether the detected physical quantity is within the range of the predetermined allowable value. Determine the deterioration state.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a main part of an electric injection molding machine of an embodiment to which the present invention is applied. Reference numeral 1 is a screw,
Reference numeral 2 is an injection servomotor that drives the screw 1 in the axial direction. A pulse coder 3 is attached to the injection servomotor 2 so that the current position of the screw 1 can be detected. The screw 1 has a pressure for detecting the injection pressure by the resin reaction force acting in the screw axial direction. A sensor 4 is provided.

The control unit 100 of the injection molding machine is a microprocessor for numerical control (hereinafter referred to as NC CPU) 1
12 and a microprocessor (hereinafter referred to as PMC CPU) 114 for a programmable machine controller, and the PMC CPU 114 stores a sequence program or the like for controlling the sequence operation of the injection molding machine.
The OM 117 and the PMC RAM 110 are connected. The NC CPU 112 has a ROM 115 that stores a management program for controlling the injection molding machine as a whole and each of a clamp, a screw rotation, an ejector, an injection unit, a mold thickness adjustment (not shown), injection, and the like. A servo circuit that drives and controls the axis servo motor is connected via a servo interface 111. In FIG. 1, only the servo circuit 103 for the injection servo motor 2 is shown.

Reference numeral 105 denotes a non-volatile shared RAM composed of a bubble memory or a CMOS memory, which has a memory section for storing an NC program for controlling each operation of the injection molding machine and various set values, parameters, macro variables, etc. And a setting memory unit for storing

Reference numeral 113 is a bus arbiter controller (hereinafter referred to as BAC), and the BAC 113 has a CP for NC.
U112, PMC CPU 114, shared RAM 10
5, each bus of the input / output circuit 107 is connected, and the BAC1
A bus used by 13 is controlled. The injection servomotor 2 is connected to the servo circuit 103, and the torque limit value from the output section of the input / output circuit 107 and the detection output from the pulse coder 3 are input to the servo circuit 103. The current position of the screw 1 is constantly detected by the position storage register. The RAM 104 is for temporary storage of data.

119 is an operator panel controller 1
Manual data input device with CRT display device (hereinafter referred to as CRT / MDI) connected to BAC 113 via 16
It is possible to input various setting data and select a display screen by displaying various setting screens and work menus on the CRT display screen and operating various operation keys.

An address generator 118 is connected to the output section of the input / output circuit 107, and RAM 108 and RAM 10 are operated by an address command from the address generator 118.
The same 9 addresses are designated. Of these, the RAM 108 stores the output signal of the pressure sensor 4 converted by the A / D converter 101 as the current injection pressure,
Further, the RAM 109 stores the up / down-counted detection signals from the pulse coder 3 as the current position of the screw 1. Address generator 118
Receives the sampling start signal output from the input / output circuit 107 at the start of injection, and the RAM 108 and the RAM 10
9 is designated, and thereafter, until the injection (including the pressure-holding step) is completed, the address designation is sequentially advanced at predetermined sampling intervals to output the address command, and R
The current injection pressure and the current screw position at each sampling time are temporarily stored in the corresponding addresses of the AM 108 and the RAM 109. Reference numeral 106 in the figure is a clock device that generates the date and time in synchronization with the standard time.

In the above configuration, the shared RAM 1
While the PMC CPU 114 performs the sequence control based on the NC program stored in 05, various molding conditions, the sequence program stored in the ROM 117, etc., the NC CPU 112 causes the servo interface 111 to the servo circuit of each axis of the injection molding machine. The injection molding machine is drive-controlled by pulse distribution through the injection molding machine, and the drive control system of the injection molding machine itself is the same as the conventional one.

In the embodiment of the present invention described below,
The memory of the ROM 117 is further provided with a condition storage file as shown in Table 1 and an allowable value storage file as shown in Table 2.

[0016]

[Table 1] The condition storage file is independent of the setting memory part of the shared RAM 105, and is set value ISFb of the screw moving speed when the screw is moved forward, set value ISBb of the screw moving speed when the screw is moved backward, and set value of the clamp moving speed when the mold is closed. ICFb, set value ICBb of clamp moving speed at mold opening, set value IRb of screw rotating speed, set value IEFb of ejector moving speed at ejector forward movement, set value IEBb of ejector moving speed at ejector retreat, during injection unit forward movement Of the injection unit moving speed at IUFb,
Set value IUBb of moving speed of injection unit when retreating injection unit, set value IDFb of moving speed of mold thickness adjusting unit when moving forward mold thickness adjusting unit, setting value of moving speed of mold thickness adjusting unit when moving backward of mold thickness adjusting unit Each of IDBb and injection pressure set value PRb is written in advance. IS
Each moving speed set value of Fb to PRb is a condition defined for driving the injection molding machine, or a part thereof,
The condition storage file further stores conditions such as the heating temperature of the injection cylinder and the measurement.

[0017]

[Table 2] The allowable value storage file is a file in which the allowable value of the drive current of each axis servo motor when driving the injection molding machine under the specified conditions is written in advance. Side injection pressure and the upper limit side injection pressure are stored.

The allowable value ISFa of the injection motor current during forward movement of the screw is the upper limit value of the drive current of the injection servomotor 2 required to drive the screw 1 forward at the set speed ISFb in the unloaded state. The allowable value ISBa of the injection motor current at the time of retreat is the upper limit value of the drive current of the injection servomotor 2 required to drive the screw 1 at the set speed ISBb in the unloaded state, and the clamp at the time of mold closing. The allowable value of the motor current ICFa is clamped in the no load condition.
The upper limit value of the drive current of the clamping servo motor required to drive in the mold clamping direction with Fb, the allowable value of the clamp motor current when opening the mold ICBa is the clamp at the set speed ICBb in the unloaded state. The upper limit value of the drive current of the clamping servo motor required for driving in the opening direction and the allowable value IRa of the screw rotation motor current during screw rotation are such that the screw 1 rotates at the set rotation speed IRb under no load. The upper limit value of the drive current of the screw rotation servo motor required for driving, and the allowable value IEFa of the current of the ejector motor during forward movement of the ejector are necessary for ejecting the ejector at the set speed IEFb in the no-load state. Upper limit of drive current of ejector servo motor, ejector motor when ejector retracts The allowable value IEBa of the current is the upper limit value of the drive current of the servo motor for the ejector required for retracting the ejector at the set speed IEBb in the no-load state, and the allowable value of the current for the injection unit motor when the injection unit moves forward. IUFa is the upper limit value of the drive current of the injection unit servomotor required to drive the injection unit forward at the set speed IUFb in the unloaded state,
The allowable value IUBa of the injection unit motor current when the injection unit is retracted is the upper limit value of the drive current of the injection unit servomotor required to drive the injection unit backward at the set speed IUBb in the unloaded state, and the mold thickness. The allowable value IDFa of the current of the die thickness adjusting motor when the adjusting portion is moved forward is the upper limit of the drive current of the die thickness adjusting servo motor required to drive the die thickness adjusting portion forward at the set speed IDFb in the no-load state. The allowable value IDBa of the current of the motor for adjusting the mold thickness when the mold thickness adjusting unit is retreated is the servo for adjusting the mold thickness required to drive the mold thickness adjusting unit backward at the set speed IDBb in the no-load state. It is the upper limit of the drive current of the motor.

In general, the drive system of each part of the injection molding machine gradually increases in resistance at the time of driving due to secular change such as volatilization and deterioration of lubricating oil, so that each part of the drive system operates at a preset moving speed. The value of the drive current of the motor required for the above also gradually increases with the passage of time. Each of the upper limit values ISFa to IDBa of the drive current that is the allowable value is a value within a range that does not hinder the operation of the injection molding machine or the injection molding work due to the deterioration of the lubricating oil and the increase of the drive resistance of each part of the drive system. The value is theoretically or experimentally set for each servomotor of each drive system.

The lower limit allowable value PRLa of the injection pressure when the injection is performed under a predetermined condition is the lower limit value of the maximum injection pressure detected by the pressure sensor 4 when the screw 1 is made to perform the injection operation under the predetermined condition. And the upper limit allowable value PRHa of the injection pressure when the injection is performed under a predetermined condition is the upper limit value of the maximum injection pressure detected by the pressure sensor 4 when the screw 1 performs the injection operation under the predetermined condition. Is set. In this case, the predetermined conditions regarding the injection include the conditions regarding application of a drive current corresponding to the set value PRb of the injection pressure to the injection servomotor 2, and conditions regarding the resin material, the cylinder temperature, the mold to be mounted, and the like. The same means that the injection operation is performed. Therefore, regarding the resin material, the cylinder temperature, the mold to be mounted, etc.,
Any condition may be determined as long as this is not changed in the middle, for example, a condition that injection is performed at a predetermined cylinder temperature using a specific type of resin without mounting a mold, or a nozzle is blocked to specify It is possible to set a condition that injection is performed at a predetermined cylinder temperature using a kind of resin, or a condition that injection is performed at a predetermined cylinder temperature using a resin of a specific type by mounting the same mold. ..

In the injection mechanism of the injection molding machine, like the other parts of the drive system, the resistance of the drive system gradually increases as the lubricating oil evaporates and deteriorates over time. Even if a corresponding drive current is applied to the injection servomotor 2, the output torque damaged by the drive resistance and the like gradually increases with the passage of time, and the value of the maximum injection pressure detected by the pressure sensor 4 gradually decreases. .. Also, the maximum injection pressure value may decrease even when the screw is worn. Generally, when the drive resistance increases or the screw wears due to volatilization or deterioration of the lubricating oil, the value of the maximum injection pressure detected by the pressure sensor 4 decreases, but the detection accuracy of the pressure sensor 4 including a load cell decreases. If the deterioration occurs, the value of the maximum injection pressure detected by the pressure sensor 4 may increase. The lower limit side allowable value PRLa and the upper limit side allowable value PRH of the injection pressure which are the allowable values
a is theoretically or experimentally a value within a range that does not hinder the operation of the injection molding machine or the injection molding work due to an increase in driving resistance of each part of the injection mechanism, wear of the screw, and deterioration of the detection accuracy of the pressure sensor 4. This is the calculated value.

2 to 8 are flow charts showing the outline of the "deterioration state detection process" in this embodiment. The ROM 11 is a sequence program executed at the time of regular inspection.
7 and is activated by selecting the item of “Periodic inspection” from the work menu of the CRT display screen of CRT / MDI 119 (hereinafter, simply referred to as CRT). Before performing this periodic inspection, it is desirable to purge the resin in the injection cylinder in advance and heat the cylinder temperature to the value set in the condition storage file. Pre-designated resin is added.

The PMC CPU 114 that has started the "deterioration state detection process" first reads the set values ISFb to PRb and the measurement conditions stored in the condition storage file of the ROM 117, and shares the values defined in the condition storage file. R
The driving conditions are set in the setting memory unit of the AM 105 (step A1).

Next, the PMC CPU 114 is an NC C
Outputs a screw forward command to PU 112 and sets speed I
The forward movement of the screw 1 is started at SFb (step A
2) The current IS flowing through the injection servomotor 2 that drives the screw 1 forward is detected (step A3). NC CPU 11 via the servo interface 111
The servo circuit 103 that received the command from the
Since the drive current of the injection servomotor 2 is controlled so that the forward speed of the injection speed becomes the set speed ISFb, if the drive resistance of the injection mechanism is increased due to deterioration of the lubricating oil or the like, the injection servo is proportional to this. The current IS flowing through the motor 2 will increase.

Next, the PMC CPU 114 uses the current value IS of the current flowing through the injection servomotor 2 and the ROM 117.
The current value IS of the current flowing in the injection servomotor 2 is compared with the current allowable value ISFa of the injection motor stored in the allowable value storage file of the screw forward when the screw advances (step A4). If it exceeds ISFa, it is determined that some deterioration has occurred in the injection mechanism,
On the CRT display screen, display a message that encourages the operator to inspect the injection mechanism, such as "Check the greasing status of the injection mechanism" (step A5), and set the display completion flag F while (Step A6) If the current current value IS does not exceed the current allowable value ISFa, the process of steps A5 and A6 is not executed and the process proceeds to the next process. In the process of step A4, the directivity of the current is different between when the screw is moving forward and when the screw is moving backward. Therefore, the absolute value of the current value IS of the current and the current allowable value ISFa are taken to compare their magnitudes. Hereinafter, when comparing the magnitude relation, it means to take the absolute value and compare the magnitude relation.

Next, the CPU 114 for PMC is the CP for NC.
Outputs the screw backward command to U112 and sets the speed IS
Start retreating the screw 1 at Bb (step A7),
The current IS flowing through the injection servomotor 2 that drives the screw 1 backward is detected (step A8). Similarly to the above, if the drive resistance of the injection mechanism increases due to deterioration of the lubricating oil or the like, the current IS flowing through the injection servomotor 2 increases in proportion to this. Therefore, the PMC CPU 11
4 compares the current value IS of the current flowing through the injection servomotor 2 with the current allowable value ISBa of the injection motor when the screw retracts stored in the allowable value storage file of the ROM 117 (step A9), The current value IS of the current flowing through the injection servomotor 2 is the current allowable value ISBa
If the display completion flag F is not set, it is further determined whether or not the display completion flag F is set (step A10). If the display completion flag F is not set, it is recommended to inspect the injection mechanism on the display screen of the CRT. A message such as "Check the greasing status of the injection mechanism" is newly displayed to stop the driving of the injection servomotor 2 (step A11, step A13), while the display completion flag F is already set. If so, the flag F is reset and the drive of the injection servomotor 2 is stopped (step A12, step A13). That is, the message regarding the same drive mechanism is not displayed in duplicate. If the determination result in step A9 is false, the display completion flag F is reset and the driving of the injection servomotor 2 is stopped (steps A12 and A13).

Next, the PMC CPU 114 is an NC C
A mold closing command is output to the PU 112 to start the mold closing operation of the clamp mechanism at the set speed ICFb (step A1.
4) Detect the current IC flowing in the clamp servomotor that closes the clamp (step A15). In the servo circuit that receives a command from the NC CPU 112 via the servo interface, the clamp mold closing speed is set to the set speed I.
Since the drive current of the clamping servo motor is controlled so as to be CFb, if the drive resistance of the clamp mechanism is increased due to deterioration of the lubricating oil or the like, the current IC flowing through the clamping servo motor increases in proportion to this. Will be done.

Next, the PMC CPU 114 has the ROM 11 and the present value IC of the current flowing through the clamping servomotor.
Although the magnitude relation with the current allowable value ICFa of the clamp motor at the time of mold closing stored in the allowable value storage file 7 is compared (step A16), the current value IC of the current flowing through the clamp servo motor is the current allowable value. If it exceeds ICFa, it is judged that some deterioration has occurred in the clamp mechanism, and a message that encourages the operator to inspect the clamp mechanism on the display screen of the CRT, such as "Check the greasing state of the clamp mechanism". Please display "etc. (step A17) and set the display completion flag F (step A18), while if the current current value IC does not exceed the current allowable value ICFa, perform the processing of steps A17 and A18. Not execute and move to the next process.

Next, the PMC CPU 114 is the NC CP.
A mold opening command is output to U112 to start the mold opening operation of the clamp mechanism at the set speed ICBb (step A19),
Current I flowing through the clamp servo motor that opens the clamp
C is detected (step A20). Similarly to the above, if the drive resistance of the clamp mechanism is increased due to deterioration of the lubricating oil or the like, the current IC flowing through the clamp servomotor increases in proportion to this. Therefore, the PMC CPU 114 uses the current value IC and R of the current flowing through the clamp servo motor.
Although the magnitude relationship with the current allowable value ICBa of the clamping motor stored in the allowable value storage file of the OM 117 at the time of mold opening is compared (step A21), the current value IC of the current flowing through the clamping servomotor is the current allowable value. If it exceeds ICBa, it is further determined whether or not the display completion flag F is set (step A22). If the display completion flag F is not set, it is recommended to check the clamp mechanism on the display screen of the CRT. Message such as “Check the greasing status of the clamp mechanism” is displayed to stop the driving of the clamping servomotor (step A23, step A25), while the display completion flag F is already set. If so, the flag F is reset and the driving of the clamping servomotor is stopped (step A24,
Step A25). If the determination result in step A21 is false, the display completion flag F is reset and the driving of the clamping servomotor is stopped (steps A24 and A25).

Next, the PMC CPU 114 is an NC C
A screw rotation command is output to the PU 112 to start the rotation of the screw 1 at the set rotation speed IRb (step A2
6) Detect the current IR flowing through the screw rotation servomotor that rotates the screw 1 (step A2).
7). NC CPU1 via servo interface
The servo circuit that receives the command from 12 controls the drive current of the screw rotation servomotor so that the rotation speed of the screw 1 becomes the set rotation speed IRb. If it increases, the current IR flowing through the screw rotation servomotor increases in proportion to this.

Next, the PMC CPU 114 causes the current values IR and RO of the currents flowing in the screw rotation servomotors.
The magnitude relationship with the current allowable value IRa of the screw rotation motor during screw rotation stored in the allowable value storage file of M117 is compared (step A28), but the current value IR of the current flowing through the screw rotation servomotor is the current. If the allowable value IRa is exceeded, it is determined that some deterioration has occurred in the screw rotation mechanism, and a message that encourages the operator to inspect the screw rotation mechanism on the display screen of the CRT, such as "Screw rotation mechanism "Please check the greasing condition" is displayed to stop the driving of the screw rotation servomotor (step A29, step A30), while the current value IR of the current does not exceed the current allowable value IRa, step A29. The process of (1) is not executed and the driving of the screw rotation servomotor is stopped (step A30).

Next, the CPU 114 for PMC is the C for NC.
Outputs an ejector forward command to the PU 112 to set speed I
The ejector ejecting operation is started at EFb (step A3
1) The current IE flowing in the ejector servomotor protruding from the ejector is detected (step A32). The servo circuit, which receives a command from the NC CPU 112 via the servo interface, controls the drive current of the ejector servomotor so that the ejecting speed of the ejector reaches the set speed IEFb. If the drive resistance increases, the current IE flowing through the ejector servomotor increases in proportion to this increase.

Next, the PMC CPU 114 determines the current value IE of the current flowing in the ejector servomotor and the ROM 1
Although the magnitude relation with the current limit value IEFa of the ejector motor during forward movement of the ejector stored in the permission value storage file 17 is compared (step A33), the current value IE of the current flowing through the ejector servomotor is the current limit value. IE
If it exceeds Fa, it is judged that the ejector mechanism has deteriorated in some way, and a message that encourages the operator to inspect the ejector mechanism is displayed on the display screen of the CRT, for example, "Check the lubrication status of the ejector mechanism. Please display "(step A34) and set the display completion flag F (step A35), while if the current current value IE does not exceed the current allowable value IEFa, step A3
4, the process of step A35 is not executed, and the process proceeds to the next process.

Next, the CPU 114 for PMC is the CP for NC.
Output ejector retract command to U112 and set speed IE
The ejector retracting operation is started at Bb (step A3
6) Detect the current IE flowing in the ejector servomotor that retracts the ejector (step A37). Similarly to the above, if the drive resistance of the ejector mechanism increases due to deterioration of the lubricating oil or the like, the current IE flowing through the ejector servomotor increases in proportion to this. So PM
The CPU 114 for C compares the current value IE of the current flowing through the ejector servomotor with the current allowable value IEBa of the ejector motor when the ejector retracts stored in the allowable value storage file of the ROM 117 (step A38). If the current value IE of the current flowing through the ejector servomotor exceeds the current allowable value IEBa, it is further determined whether or not the display completion flag F is set (step A39), and the display completion flag F is set. If not, a message that encourages inspection of the ejector mechanism is displayed on the display screen of the CRT, for example, "Please check the greasing status of the ejector mechanism", and the drive of the ejector servomotor is stopped ( Step A40,
If the display completion flag F has already been set (step A42), the flag F is reset and driving of the ejector servomotor is stopped (steps A41, A42). If the determination result in step A38 is false, the display completion flag F is reset and the drive of the ejector servomotor is stopped (steps A41 and A42).

Next, the PMC CPU 114 is an NC C
The injection unit advance command is output to the PU 112 to start the advance of the injection unit at the set speed IUFb (step A4
3) Detect the current IU flowing through the injection unit servomotor that advances the injection unit (step A4).
4). NC CPU1 via servo interface
The servo circuit that receives the command from 12 controls the drive current of the injection unit servomotor so that the forward speed of the injection unit becomes the set speed IUFb, so that the drive resistance of the injection unit drive mechanism is reduced due to deterioration of lubricating oil or the like. If it has increased, the current IU flowing through the injection unit servomotor will increase in proportion to this.

Next, the PMC CPU 114 determines the current value IU of the current flowing through the injection unit servomotor and the ROM.
Although the magnitude relation with the current allowable value IUFa of the injection unit motor when the injection unit advances when stored in the allowable value storage file 117 is compared (step A45), the current value IU of the current flowing through the injection unit servomotor is calculated. If the current permissible value IUFa is exceeded, it is determined that the injection unit drive mechanism has deteriorated, and the CRT display screen displays a message that encourages inspection of the injection unit drive mechanism, such as "Injection unit drive mechanism". Please check the greasing condition of the mechanism "(step A46) and set the display completion flag F (step A47), while the current current value IU does not exceed the current allowable value IUFa,
The processing of steps A46 and A47 is not executed, and the process proceeds to the next processing.

Next, the CPU 114 for PMC is the CP for NC.
Output the injection unit retract command to U112 and set speed I
Start retreat of the injection unit at UBb (step A4
8) Detect the current IU flowing through the injection unit servomotor that retracts the injection unit (step A4).
9). Similarly to the above, if the drive resistance of the injection unit drive mechanism increases due to deterioration of the lubricating oil or the like, the current IU flowing through the injection unit servomotor increases in proportion to this. Therefore, the PMC CPU 114 uses the current value IU of the current flowing in the injection unit servomotor and the ROM 117.
The magnitude relationship with the current allowable value IUBa of the injection unit motor when the injection unit is retracted stored in the allowable value storage file is compared (step A50), but the current value IU of the current flowing through the injection unit servomotor is the current. Allowable value I
If it exceeds UBa, it is further determined whether or not the display completion flag F is set (step A51). If the display completion flag F is not set, the injection unit drive mechanism is inspected on the display screen of the CRT. A message encouraging the user is displayed, for example, "please check the greasing state of the injection unit drive mechanism", and the driving of the injection unit servomotor is stopped (step A52, step A5).
4) If the display completion flag F has already been set, the flag F is reset and driving of the injection unit servomotor is stopped (steps A53, A54).
If the determination result in step A50 is false, the display completion flag F is reset and the driving of the injection unit servomotor is stopped (step A5).
3, step A54).

Next, the PMC CPU 114 is an NC C
Outputs the mold thickness adjustment unit forward command to PU 112 to set speed I
DFb starts the advance of the mold thickness adjusting unit (step A5
5) The current ID flowing in the mold thickness adjusting servomotor that advances the mold thickness adjusting unit is detected (step A56). The servo circuit that receives a command from the NC CPU 112 via the servo interface controls the drive current of the mold thickness adjusting servomotor so that the advance speed of the mold thickness adjusting unit becomes the set speed IDFb. If the drive resistance of the die thickness adjusting portion is increased due to the above reasons, the current ID flowing through the die thickness adjusting servomotor is increased in proportion to this.

Next, the PMC CPU 114 reads the current value ID of the current flowing through the die thickness adjusting servomotor and the ROM 11.
Although the magnitude relation with the current allowable value IDFa of the mold thickness adjusting motor stored in the allowable value storage file of No. 7 is advanced (step A57), the current flowing through the mold thickness adjusting servomotor is compared. If the current value ID exceeds the allowable current value IDFa, it is determined that some deterioration has occurred in the mold thickness adjusting unit, and a message that encourages the inspection of the mold thickness adjusting unit on the display screen of the CRT, for example, Display "Please check the greasing condition of the mold thickness adjustment part" etc. (step A58),
While the display completion flag F is set (step A5
9) If the current current value ID does not exceed the current allowable value IDFa, the process of steps A58 and A59 is not executed and the process proceeds to the next process.

Next, the CPU 114 for PMC is the CP for NC.
Set the speed ID by outputting the mold retraction command to U112
Start retreat of the mold thickness adjusting part at Bb (step A60),
The current ID flowing through the mold thickness adjusting servomotor that retracts the mold thickness adjusting unit is detected (step A61). Similarly to the above, if the drive resistance of the mold thickness adjusting portion increases due to deterioration of the lubricating oil or the like, the current ID flowing through the mold thickness adjusting servomotor increases in proportion to this. Therefore, PMC CPU
Reference numeral 114 denotes the current value ID of the current flowing in the mold thickness adjusting servomotor and the current allowable value ID of the mold thickness adjusting motor when the mold thickness adjusting unit is retracted, which is stored in the allowable value storage file of the ROM 117.
The magnitude relationship with Ba is compared (step A62), but if the current value ID of the current flowing through the mold thickness adjusting servomotor exceeds the current allowable value IDBa, it is determined whether the display completion flag F has been set. Is determined (step A6
3) If the display completion flag F is not set, C
On the RT display screen, a message that encourages inspection of the mold thickness adjustment unit, for example, "Check the greasing condition of the mold thickness adjustment unit" is displayed and the servo motor for mold thickness adjustment is stopped. (Step A64, Step A66) If the display completion flag F is already set, the flag F is reset to stop the driving of the die thickness adjusting servomotor (Step A65, Step A66). Further, when the determination result of step A62 is false, the display completion flag F is reset and the driving of the die thickness adjusting servomotor is stopped (steps A65 and A6).
6).

Next, the PMC CPU 114, which has stopped the driving of the mold thickness adjusting servomotor, guides the injection operation for detecting the deterioration state, for example, "a condition in which the cylinder temperature, the resin used, the mold, etc. are determined. Please confirm that they match and operate the injection execution key "or the like is displayed (step A67), and a standby state is waited for the operator to operate the injection execution key (step A68).

The operator referring to the guidance display of the CRT inspects the resin material in the hopper so as to make the resin material, the cylinder temperature, the mold to be mounted, and the like the same as the predetermined conditions. Make sure that the temperature has reached the specified value, and in accordance with the predetermined conditions, leave the mold unattached, or close the nozzle, or insert the specified mold and inject. Operate the execute key.

The PMC CPU 114, which has detected the operation of the injection execution key in the discrimination processing of step A68, is in the ROM 11
The metering process is executed according to the metering conditions read from 7 to the setting memory unit of the shared RAM 105 (step A69), a constant torque limit corresponding to the set injection pressure PRb is set in the servo circuit 103, and the injection servomotor 2 is driven. The upper limit of the drive current is regulated (step A70). When the conditions for mounting the mold and performing the injection operation are determined, the mold clamping operation and the nozzle touch operation are performed in advance before the start of weighing.

Then, the PMC with the torque limit set
CPU 114 outputs an injection start command to NC CPU 112 to drive injection servo motor 2 and screw 1
The injection operation is started (step A71). As a result of the upper limit of the drive current of the injection servo motor 2 being restricted, the injection servo motor 2 is not driven beyond the torque limit, and the drive resistance of the injection mechanism increases due to volatilization or deterioration of the lubricating oil. If the screw is worn or the screw is abraded, the substantial resin reaction force acting on the screw 1, that is, the value of the injection pressure detected by the pressure sensor 4 decreases correspondingly. Pressure sensor 4
When the detection accuracy deteriorates, the value of the injection pressure output from the pressure sensor 4 may increase even if the substantial injection pressure decreases.

CPU 114 for PMC which has started the injection operation
Waits until the injection / holding pressure completion signal is input from the NC CPU 112 (step A72), and when the input of the injection / pressure holding completion signal is confirmed, the injection pressure data stored in the RAM 108 is searched. The maximum injection pressure PR is detected (step A73), and the value of the maximum injection pressure PR is the lower limit side allowable value PRL of the injection pressure stored in the allowable value storage file.
It is determined whether it is included between a and the upper limit allowable value PRHa (step A74), and the maximum injection pressure PR is smaller than the lower limit allowable value PRLa or larger than the upper limit allowable value PRHa. In this case, a message that encourages inspection of the injection mechanism on the display screen of the CRT, for example,
"Check the lubrication status of the injection mechanism and the deterioration status of the load cell" is displayed and the "deterioration status detection process" ends (step A75), while the maximum injection pressure PR becomes the lower limit allowable value PRLa. If it is included between the upper limit value PRHa and the upper limit value PRHa, the greasing state of the injection mechanism and the pressure sensor 4
It is considered that both functions are normal, and the process of step A75 is not executed, and the “deterioration state detection process” ends.

According to the "deterioration state detection process" of this embodiment, the injection mechanism is selected by simply selecting the item "regular inspection" from the work menu of the CRT / MDI 119 and driving the injection molding machine with a predetermined program. , Clamp mechanism, screw rotation mechanism, ejector mechanism, injection unit drive mechanism,
Since it is possible to individually judge and display whether or not each part such as the mold thickness adjustment part has deteriorated, which is a substantial hindrance, strict inspection and readjustment only for the part where an abnormality is displayed It is sufficient to perform the work, and the troublesome work related to the periodic inspection can be significantly reduced.

Further, in addition to the allowable value storage file shown in Table 2, that is, the file storing the allowable values used in the periodic inspection, a second allowable value storage file storing the allowable values used in the shipping inspection is provided in the ROM 117. If a process equivalent to that shown in FIGS. 2 to 8 is carried out by using the allowable value stored in the second allowable value storage file at the time of inspection at the time of shipment, it is possible to determine whether the manufacturer can ship the product. It is also possible to determine whether readjustment is necessary or not.

In this case, steps A5, A11, A17, A23, A29, A34, A4 in FIGS.
In the processing corresponding to 0, A46, A52, A58, A64, A75, a message requesting readjustment work before shipping is displayed instead of the message encouraging inspection. In the routine inspection process shown in FIGS. 2 to 8, a similar message is displayed to encourage the inspection when an abnormality is detected in at least one of the frontward retreat of the inspection location and the upper and lower limits of the injection pressure. However, since more detailed information may be required during the shipping inspection stage, any abnormalities that may occur when the inspection point moves forward or backward, and abnormalities or lower limits when the injection pressure exceeds the upper limit. It is also possible to individually display the readjustment request message for each abnormality in the case of less than.

That is, each step A6, A10, A12, A18, which is seen in the processing at the time of the periodical inspection shown in FIGS.
A22, A24, A35, A39, A41, A47, A
The processes of 51, A53, A59, A63, A65 are not necessary, and when an abnormal drive current is detected when the inspection point is moved forward or backward, "The resistance at the screw forward is too large, please readjust. Re-adjustment request message such as "" or "Resistance when screw retracts is too large, please re-adjust" is displayed individually. Further, in the process corresponding to step A74, the PR <PRLa true / false determination and the PR> PRHa true / false determination are individually performed, and the readjustment request message also indicates, for example, “resistance at injection is too large. First, display a message such as "Please readjust" or "There is a possibility of abnormality in the load cell or system, please check."
Usually, the value of the tolerance value stored in the second tolerance value storage file is set more severely than the tolerance value stored in the tolerance value storage file for periodic inspection (Table 2).

As described above, the allowable value of the drive current and the allowable value of the injection pressure of each axis servo motor when the injection molding machine is driven under the defined conditions are uniquely common to the injection molding machines of the same standard. An example was described in which the presence or absence of deterioration was determined by comparing the values with the actual motor drive current and injection pressure values that were determined and stored in the allowable value storage file and detected during the regular inspection stage. Even if the injection molding machine of the same standard is adjusted to an ideal state due to the individual difference of the machine, that is, the size and shape error within the processing tolerance, the value of the drive current of each axis and the constant value under the specified conditions There may be a difference in the injection pressure value under the torque limit of.

Therefore, when the injection molding machine is adjusted to an ideal state at the time of shipment, each part of the injection molding machine is operated under the predetermined conditions, and the measured values of the drive currents of the respective axis servo motors and the injection current at this time are injected. Calculate the allowable values of the drive current and injection pressure of each axis servo motor at the time of regular inspection based on the measured pressure value, and perform regular inspection based on these allowable values to determine the presence or absence of deterioration. Is also good. In this case, the memory of the shared RAM 105 is provided with an allowable value storage file as shown in Table 2 in a blank state, and the ROM 117
Is provided with a condition storage file as shown in Table 1 and an allowable width storage file as shown in Table 3.

[0052]

[Table 3] The allowable width storage file is used for the operation of the injection molding machine and the injection molding for the measured values of the drive current and injection pressure of each axis servo motor when the ideally adjusted injection molding machine is driven under the specified conditions. This is a file that stores the value of the allowable width of the range in which work can be performed without any problems.

9 to 13 are flowcharts showing the outline of the "permissible value setting storage process" for calculating the permissible value. The ROM 117 is a sequence program executed when the assembly and adjustment of the injection molding machine are completed. And is activated by selecting the item "tolerance setting" from the work menu on the CRT display screen. It should be noted that it is desirable to heat the cylinder temperature to a value set in the condition storage file before carrying out this process, and a resin designated in advance is put into the hopper.

PMC which has started the "permissible value setting storage process"
The CPU 114 first reads the set values ISFb to PRb and the measurement conditions stored in the condition storage file of the ROM 117, and sets the values defined in the condition storage file in the setting memory section of the shared RAM 105 as the driving conditions (steps). B1).

Next, the PMC CPU 114 is an NC C
Outputs a screw forward command to PU 112 and sets speed I
The forward movement of the screw 1 is started at SFb (step B
2), a current IS flowing in the injection servomotor 2 that drives the screw 1 forward, that is, a drive current IS required to drive the ideally adjusted injection molding machine forward at a predetermined speed condition. The value of (step B3),
The allowable width ISFc of the current of the injection motor at the time of screw forward stored in the allowable width storage file of the ROM 117 is added to calculate the allowable value of the current of the injection motor at the time of screw forward, and this value is Non-volatile shared RA
The allowable value storage file set in M105 is stored as the allowable value ISFa of the injection motor current when the screw advances (step B4).

Then, the PMC CPU 114 is an NC C
Outputs a screw backward command to PU112 and sets speed I
SBb starts to retract screw 1 (step B
5), a current IS flowing in the injection servomotor 2 for driving the screw 1 backward, that is, a drive current IS required for backward driving an ideally adjusted injection molding machine under a predetermined speed condition. The value of (step B6),
The allowable width ISBc of the current of the injection motor when the screw is retracted, which is stored in the allowable width storage file of the ROM 117, is added to calculate the allowable value of the current of the injection motor when the screw is retracted. Non-volatile shared RA
After the allowable value ISBa of the current of the injection motor at the time of retreating the screw is stored in the allowable value storage file set in M105 (step B7), the driving of the injection servomotor 2 is stopped (step B8).

Hereinafter, the PMC CPU 114 moves the clamp mechanism forward and backward under the predetermined speed conditions ICFb and ICBb to stop, and also drives and stops the screw rotation mechanism at the predetermined rotation speed IRb, and the ejector. And speed conditions IEFb, IEBb, IUFb, IUB that are respectively set for the injection unit and the mold thickness adjusting unit.
b, IDFb, and IDBb are moved backward to stop, and the values of the drive currents IC, IR, IE, IU, and ID obtained by actually measuring the current flowing in the servo motor of each axis at the time of forward reverse are supported. Allowable width storage file values ICFc, ICB
c, IRc, IEFc, IEBc, IUFc, IUB
c, IDFc, and IDBc are added to determine the allowable current ICFa of the clamping motor current when the mold is closed, the allowable current ICBa of the clamping motor current when the mold is opened, and the current of the screw rotation motor when the screw is rotating. Allowable value IRa,
Allowable value IEFa of current for ejector motor when ejector moves forward, Allowable value IEBa of current for ejector motor when ejector retracts, Allowable value of current for injection unit motor IUFa when ejecting unit moves forward, Injection when ejecting unit moves backward Allowable current IUBa of the unit motor current, allowable ID of the current of the mold thickness adjusting motor when the mold thickness adjusting unit is advanced
Fa and the allowable value IDBa of the current of the mold thickness adjusting motor when the mold thickness adjusting portion is retracted are calculated, and the values of the respective allowable values are shared R
The data is stored in the allowable value storage file of the AM 105 in a non-volatile manner (step B9 to step B40).

Next, the PMC CPU 114 executes the injection after confirming that the injection operation guidance for setting the allowable value, for example, "cylinder temperature, resin to be used, mold, etc., matches the predetermined conditions. Please operate the key "and the like are displayed (step B41), and a standby state waiting for the operation of the injection execution key by the operator is entered (step B42).

On the other hand, the operator who refers to the guidance display of the CRT selects the resin material in the hopper in order to make the resin material, the cylinder temperature, the mold to be mounted, and the like the same as the predetermined conditions. Inspect and confirm that the cylinder temperature has reached the specified value, and according to the predetermined conditions, without mounting the mold,
Alternatively, the injection execution key is operated by closing the nozzle or mounting a predetermined mold.

The PMC CPU 114, which has detected the operation of the injection execution key in the determination processing of step B42, is in the ROM 11
The metering process is executed according to the metering conditions read from 7 to the setting memory unit of the shared RAM 105 (step B43), a constant torque limit corresponding to the set injection pressure PRb is set in the servo circuit 103, and the injection servomotor 2 is driven. After controlling the upper limit of the drive current (step B44), C for NC
An injection start command is output to the PU 112 to drive the injection servomotor 2 to start the injection operation of the screw 1 (step B45).

CPU 114 for PMC which has started the injection operation
Waits until the injection / holding pressure completion signal is input from the NC CPU 112 (step B46), searches the injection pressure data stored in the RAM 108, and determines the maximum injection pressure PR.
Is detected (step B47), and the lower limit of the injection pressure when the injection is performed under a predetermined condition from the value of the maximum injection pressure PR when the injection operation is performed by the ideally adjusted injection molding machine with the predetermined driving torque is performed. The value of the side allowable width PRLc is subtracted, the lower limit allowable value of the injection pressure when the injection is performed under the predetermined condition is calculated, and the lower limit allowable value PR is stored in the allowable value storage file of the shared RAM 105.
The data is non-volatilely stored as La (step B48),
The upper limit allowable width PRHc of the injection pressure when the injection is performed under a predetermined condition to the value of the maximum injection pressure PR when the injection operation is performed at a predetermined driving torque in the ideally adjusted injection molding machine.
Value is added to calculate the upper limit allowable value of the injection pressure at the time of injection under a predetermined condition, and is nonvolatilely stored as the upper limit allowable value PRHa in the allowable value storage file of the shared RAM 105 (step B49). The setting storage process "is ended.

The process at the time of regular inspection performed using the allowable value stored in the allowable value storage file of the shared RAM 105 in a nonvolatile manner is the same as that shown in FIGS. 2 to 8. However, in this case, the allowable values ISFa to PRHa are set. Since the value of is set based on the individual difference of each injection molding machine, the influence of size and shape error at the time of processing completion, that is, only the deterioration due to aging regardless of the initial state of the injection molding machine The presence or absence of abnormality can be determined as a reference. In addition, instead of storing the allowable value calculated based on the measured value of the drive current of each axis servo motor or the measured value of the injection pressure in the shared RAM 105 in the above-mentioned “allowable value setting storage process”, the injection molding machine is operated. The measured value of the drive current of each axis servo motor and the value of the injection pressure measured at the stage of adjusting to the ideal state are non-volatilely stored in the shared RAM 105 as they are, and are stored in the allowable width storage file of the ROM 117 at the stage of regular inspection. The value of each allowable width is read, and the allowable value is calculated by adding or subtracting to each of the measured values stored in the shared RAM 105 in a nonvolatile manner, and the allowable value and the drive current of each axis servo motor detected in the periodic inspection are calculated. The presence or absence of deterioration may be determined by comparing the measured value and the injection pressure value.

For each of the above-described embodiments, the display format of the message encouraging inspection is changed, the measured value of the drive current of each axis servo motor and the value of the injection pressure are saved, and the periodical operation is performed. The necessity of inspection is judged after purchasing the injection molding machine or based on the value of the number of days elapsed or the number of shots since the last regular inspection, and the regular inspection is performed by the command from the cell controller that manages multiple injection molding machines. Can be carried out.

Next, the measured value of the drive current of each axis servo motor detected during the periodic inspection and the magnitude of the injection pressure, that is,
An example will be described in which messages that encourage inspection are displayed in layers according to the degree of deterioration. In this case, as shown in Table 4 and Table 5, the allowable value storage file of the ROM 117 or the shared RAM 105 is within a range in which an increase in driving resistance of each part of the mechanism does not adversely affect the operation of the injection molding machine and the injection molding work. A small allowable value and an allowable value within the range where the function can be recovered by a simple operation such as greasing, although there may be adverse effects if the operation of the injection molding machine or injection molding work is continued as it is, In addition, three stages of a large allowable value of a range in which the function can be restored by the user's adjustment work and greasing based on the attached manual are individually set for each item.

[0065]

[Table 4]

[0066]

[Table 5] FIG. 14 and FIG. 15 are flowcharts showing a part of the “deterioration state detection processing” in which the messages are displayed hierarchically.

The PMC CPU 114 that has started the "deterioration state detection process" first reads the set values ISFb to PRb and the measurement conditions stored in the condition storage file of the ROM 117, and shares the values defined in the condition storage file. R
The driving conditions are set in the setting memory unit of the AM 105 (step C1).

Next, the PMC CPU 114 is the NC C
Outputs a screw forward command to PU 112 and sets speed I
The forward movement of the screw 1 is started at SFb (step C
2) Detect the current IS flowing through the injection servo motor 2 that drives the screw 1 forward (step C3), and read the current value IS of the current flowing through the injection servo motor 2 and the ROM.
117 or the magnitude relationship with the current tolerance value ISFa1 (large tolerance value) of the injection motor at the time of screw advance stored in the tolerance value storage file of the shared RAM 105 (step C4). If the current value IS of the current flowing through the injection servomotor 2 exceeds the allowable current value ISFa1, it is determined that the injection mechanism has deteriorated with difficulty in recovery, and the CRT display screen has deterioration that is difficult to recover. Is displayed and a message indicating that the manufacturer needs to make adjustments, for example, "Injection mechanism is abnormal, please contact the manufacturer" is displayed (step C7), and the display state storage flag F is displayed. 3 is set (step C8).

Further, if the determination result of step C4 is false and the current value IS of the current flowing through the injection servomotor 2 does not exceed the current allowable value ISFa1 of the injection motor when the screw advances, the current value of the current is further increased. IS and ROM 117
Alternatively, the current allowable value IS of the injection motor at the time of screw advance stored in the allowable value storage file of the shared RAM 105
The magnitude relationship with Fa2 (permissible value inside) is compared (step C5). The current value IS of the current is the current allowable value IS
If it is between Fa1 and the allowable current value ISFa2, it is determined that the function can be restored by the user's adjustment work and greasing based on the attached manual, and the CRT display screen displays
A message requesting user adjustment work and greasing, for example, "grease the injection mechanism, refer to the manual and perform an inspection" etc. is displayed (step C9), and 2 is displayed in the display state storage flag F. Is set (step C10).

Furthermore, if the result of the determination in step C5 is false and the current value IS of the current flowing through the injection servomotor 2 does not exceed the current allowable value ISFa2 of the injection motor when the screw advances, the current value IS Current allowable value ISFa3 of the injection motor at the time of screw advance stored in the allowable value storage file of the ROM 117 or the shared RAM 105
Compare the magnitude relationship with (small tolerance) (step C
6). Then, the current value IS of the current is the current allowable value ISFa.
If it is between 2 and the allowable current value ISFa3, there is a possibility that the operation of the injection molding machine or the injection molding work will continue to be adversely affected, but the function can be restored by simple work such as greasing. If it is determined that there is something, a message requesting lubrication, for example, "please greasing the injection mechanism" is displayed on the CRT display screen (step C11), and 1 is set in the display state storage flag F. On the other hand (step C12), if the current value IS of the current is less than the current allowable value ISFa3, no message is displayed.

Next, the PMC CPU 114 sets the NC CP
Outputs the screw backward command to U112 and sets the speed IS
Start the backward movement of the screw 1 at Bb (Step C1
3) Detect the current IS flowing through the injection servomotor 2 that drives the screw 1 backward (step C14),
Current values IS and RO of the current flowing through the injection servomotor 2
The magnitude relation with the current allowable value ISBa1 (large allowable value) of the injection motor at the time of screw retreating stored in M117 or the allowable value storage file of the shared RAM 105 is compared (step C15). If it is determined that the current value IS of the current exceeds the current allowable value ISBa1,
Whether 3 is set in the display state storage flag F,
That is, it is determined whether or not a message indicating that the injection mechanism has deteriorated due to recovery is already displayed on the CRT (step C24). If this message is not displayed, the message is displayed at step C9 or step C11. A message regarding the injection mechanism, that is, a message regarding an abnormality that is milder than the detected amount this time is once deleted (step C2).
5) Then, a message is displayed again when the injection mechanism has deteriorated, which is difficult to recover (step C26), and the display state storage flag F is reset (step C20).
When a message indicating that the injection mechanism has deteriorated due to recovery is already displayed, that is, the display state storage flag F
If 3 is set to, the message displayed in step C7 is left as it is and the process related to re-display is not performed.

If the determination result of step C15 is false and the current value IS of the current flowing through the injection servomotor 2 does not exceed the current allowable value ISBa1 of the injection motor when the screw is retracted, the current value of the current is further increased. IS and ROM 11
7 or the allowable current value I of the injection motor when the screw is retracted, which is stored in the allowable value storage file of the shared RAM 105.
The magnitude relationship with SBa2 (medium allowable value) is compared, and the current value IS of the current is the current allowable value ISBa1 and the current allowable value ISB.
It is determined whether or not it is between a2 and a2 (step C1
6). Then, the current value IS of the current is the current allowable value ISBa.
If it is between 1 and the allowable current value ISBa2, it is based on whether or not the display state storage flag F is set to 2 or 3, that is, based on the message or the attached manual when the injection mechanism is deteriorated to be difficult to recover. It is determined whether or not a message indicating that the function can be restored by the user's adjustment work and greasing is already displayed on the CRT (step C21). If no message is displayed, the message is displayed at step C11. The message relating to the injection mechanism, that is, the message relating to an abnormality that is milder than the detected amount this time is once deleted (step C22), and a message indicating that the user needs to perform adjustment work and greasing based on the attached manual is displayed again. (Step C23), the display state storage flag F is reset (step C20). If the message indicating that the injection mechanism has deteriorated or that the function can be restored by the user's adjustment work and greasing based on the attached manual has already been displayed, that is, the display state storage flag If F is set to 2 or 3, the message displayed in step C7 or step C9 is left as it is, and the process related to redisplay is not performed.

Furthermore, if the result of the determination in step C16 is false and the current value IS of the current flowing through the injection servomotor 2 does not exceed the current allowable value ISBa2 of the injection motor when the screw is retracted, then the current value of the current is next. IS and ROM1
17 or the magnitude relation with the current allowable value ISBa3 (small allowable value) of the injection motor at the time of screw retreat stored in the allowable value storage file of the shared RAM 105 is compared, and the current value IS of the current is compared with the current allowable value ISBa2. Allowable current value IS
It is determined whether or not it is between Ba3 (step C17). Then, if the current value IS of the current is between the current allowable value ISBa2 and the current allowable value ISBa3, whether or not the value of the display state storage flag F is 0, that is, some message regarding the injection mechanism has already been issued. It is determined whether or not it is displayed on the CRT (step C18), and if the value of the display state storage flag F is 0 and no message is displayed, a message for requesting lubrication to the injection mechanism is newly issued. Is displayed (step C19), and the display state storage flag F is reset (step C20). If the display state storage flag F has a value other than 0 and some message has already been displayed, this message is left and the process related to redisplay is not performed. Also,
If the current value IS of the current does not reach the current allowable value ISBa3, the display process of step C19 is not executed. Therefore, in this embodiment, among the deterioration states detected by retracting the respective parts of the mechanism to the front, a message corresponding to a deterioration state that is more severe is displayed.

After the processing of step C20 is completed, the PMC CPU 114 stops the driving of the screw 1 and then further advances and stops the clamp mechanism at the predetermined speed conditions ICFb and ICBb and then stops. The screw rotation mechanism is driven and stopped at the rotation speed IRb, and the ejector, the injection unit, and the mold thickness adjusting unit are respectively set with predetermined speed conditions IEFb, IEBb, IU.
Drive current values IC, IR, IE, IU, ID obtained by actually measuring the current flowing through the servo motor of each axis at the time of forward reversing and stopping by Fb, IUBb, IDFb, IDBb
For each of the above, if the increase in drive resistance of each part of the mechanism does not adversely affect the operation of the injection molding machine or the injection molding work, and a small allowable value, and if the operation of the injection molding machine or the injection molding work is continued as it is, Allowable value within the range where functions can be restored by simple work such as greasing, which may have an adverse effect, and range where functions can be restored by user adjustment work and greasing based on the attached manual. Of each of these values, and then the injection operation is performed under the prescribed conditions, and the magnitude relationship between the injection pressure at this time and the allowable values of the three levels is compared to determine the degree of deterioration. Although different messages will be displayed on the CRT, the determination and display processing performed for each mechanism unit is the same as that shown in FIGS. 14 and 15, and therefore, the process relating to other mechanism units will be described in the flowchart. Display and detailed It will not be bright.

Next, an example in which the measured value of the drive current of each axis servo motor and the value of the injection pressure which are detected are stored each time a periodic inspection is carried out will be described. In this case, ROM11
In addition to the condition storage file and the allowable value storage file of No. 7, the inspection result storage file as shown in Table 6 is provided in the shared RAM 105 in a blank state.

[0076]

[Table 6] FIG. 16 is a flowchart showing a part of the “deterioration state detection / storage processing” in which the actual measurement value of the drive current of each axis servo motor and the value of the injection pressure are stored each time a periodic inspection is performed.
This process is similar to the above-mentioned “deterioration state detection process”
It is started by selecting the item "Periodic inspection" from the work menu on the display screen.

PM that has started the "deterioration state detection and storage process"
The CPU 114 for C first increments the value of the inspection count integration index j initialized at the time of shipment by 1, and
The current date is read from 06, and the current value of the shot number counter of the shared RAM 105 that stores the number of executions of the molding cycle of the injection molding machine is detected (step D1,
Step D2), the current date and the current value of the shot number counter are stored in each of the j-th columns of the item of the inspection date and the number of shots at the inspection in the inspection result storage file (step D3). Next, the PMC CPU 114
The set value I stored in the condition storage file of the ROM 117
The values SFb to PRb, the measurement conditions, and the like are read, and the values set in the condition storage file are set in the setting memory unit of the shared RAM 105 as drive conditions (step D4).

Next, the PMC CPU 114 is an NC C
Outputs a screw forward command to PU 112 and sets speed I
The forward movement of the screw 1 is started at SFb (step D
5) The current IS flowing in the injection servomotor 2 for driving the screw 1 forward is detected (step D6), and the current motor IS for current injection and the injection motor during screw forward stored in the allowable value storage file of the ROM 117 are detected. Of the current allowable value ISFa is compared (step AD7).
Then, the current value I of the current flowing through the injection servomotor 2
If S exceeds the allowable current value ISFa, it is determined that the injection mechanism is deteriorated in some way, and a message for encouraging the operator to inspect the injection mechanism on the display screen of the CRT, such as "Injection mechanism" is displayed. Please check the greasing condition of
Etc. are displayed and the display completion flag F is set (step D
8, step D9), the value of the current value IS of the current flowing through the injection servo motor 2 is stored in the j-th column of the item of the injection motor current when the screw advances in the inspection result storage file (step D10). If the current value IS of the current does not exceed the current allowable value ISFa, step D
8, the process of step D9 is not executed, and step D1
Only the registration process of 0 is executed.

The PMC CPU 114, which has completed the processing of step D10, outputs a backward command of the set speed ISBb to the screw 1, detects the drive current IS and stops the drive of the screw 1, and then further defines the clamp mechanism. The vehicle is moved backward and stopped under the speed conditions ICFb and ICBb,
Further, the screw rotation mechanism is driven and stopped at a predetermined rotation speed IRb, and each of the ejector, the injection unit, and the mold thickness adjusting unit has a predetermined speed condition IE.
Fb, IEBb, IUFb, IUBb, IDFb, ID
The drive current values IS and I obtained by measuring the current flowing through the servo motor of each axis at the time of forward reversing
C, IR, IE, IU, and ID are each the injection motor current when the screw is retracted in the inspection result storage file,
Clamping motor current when the mold is closed, Clamping motor current when the mold is open, Screw rotation motor current when the screw is rotating, Ejector motor current when the ejector is moving forward, Ejector motor current when the ejector is moving backward , Injection motor current when the injection unit moves forward, injection motor current when the injection unit moves backward, drive current of mold thickness adjusting motor when the mold thickness adjusting unit moves forward, mold thickness adjusting when the mold thickness adjusting unit moves backward The motor driving current is stored in the j-th column of each item, the injection operation is performed under a predetermined condition, and the maximum injection pressure PR at this time is stored in the j-th column of the injection pressure in the inspection result storage file. At the same time, various messages corresponding to the detected current and the detected injection pressure will be displayed on the CRT. As shown in 16 and because it is equal,
With respect to the processing relating to the other mechanical units, the display of the flowchart and the detailed description are omitted. The display completion flag F is used for avoiding duplicate display of the same message as in the above-mentioned “deterioration state detection process”.

In this embodiment, the number j of periodical inspections corresponds to the date of periodical inspections, the integrated value of the number of shots at that time, the drive current value of each part, and the injection pressure value in a one-to-one correspondence. Since it is recorded as, it is possible to easily know the relationship between the progress of deterioration of each drive unit and the usage period and operating rate, and it is possible to carry out more appropriate adjustment work. The contents of the inspection result storage file are displayed on the CRT screen in response to a data request from the CRT / MDI 119. The storage destination of the inspection result is not limited to the shared RAM 105, but may be another external storage device, and a file for each injection molding machine is provided and stored in the storage means of a single cell controller connected to a plurality of injection molding machines. It is also possible to do so.

In the following, the embodiment and a plurality of injection molding machines in which the necessity of the periodical inspection is judged based on the value of the number of days elapsed or the number of shots after the purchase of the injection molding machine or the last regular inspection is managed. A brief description will be given of an embodiment in which the periodic inspection is carried out in response to a command from the cell controller.

FIG. 17 shows a CP for the PMC in order to determine whether regular inspection is necessary or not based on the number of days elapsed from the previous regular inspection.
It is a flowchart which shows the outline of the process which U114 implements at the stage immediately after a power supply is turned on.
First, the present value of the date is read from the timepiece device 106 (step E1), and whether or not this value has reached the value of the scheduled inspection date set in the shared RAM 105 by the manufacturer in advance at the shipping stage of the injection molding machine. Is determined (step E2). If the current value of the date reaches the value of the scheduled inspection date, the operator waits until the operator operates the regular inspection execution key of the CRT / MDI 119 or operates the regular inspection release key ( Step E3, Step E4).

When the operator operates the periodic inspection execution key, the PMC CPU 114 executes the above-mentioned "deterioration state detection process" and "deterioration state detection storage process" and displays a message regarding the deterioration state of each part on the CRT ( (Step E5), after adding the number of days to carry out the periodic inspection to the value of the scheduled inspection date set in the shared RAM 105 at this stage and updating and storing it in the shared RAM 105 as a new scheduled inspection date ( In step E6), the processing operation is started based on the same sequence as the conventional one. Also, if the current date value does not reach the scheduled inspection date value, or if the operator defers the periodic inspection, PM
The CPU 114 for C does not execute the processing of steps E5 and E6 and immediately starts the processing operation based on the same sequence as the conventional one.

FIG. 18 is a flow chart showing the outline of the processing executed by the PMC CPU 114 immediately after the power is turned on in order to determine the necessity of periodical inspection based on the value of the number of shots. 17 differs from the example shown in FIG. 17 in that the number of shots to be inspected is set and the number of days at which regular inspection is to be performed is set to the number of shots in which regular inspection is to be performed, but the overall algorithm is the example shown in FIG. According to the embodiment shown in FIG. 17 and FIG. 18, which is similar to
In particular, when the "deterioration state detection storage process" is performed in the processes of step E5 and step F5, the date and time when the regular inspection is performed and the step size of the number of shots are equalized. It is possible to accurately analyze the relationship between the progress status of deterioration, the usage period, and the operating rate, and it is possible to more accurately understand the deterioration tendency of each part.

FIG. 19 is a flow chart showing the outline of the processing of the embodiment in which the periodic inspection is carried out in response to a command from the cell controller which manages a plurality of injection molding machines.
The determination process of step E2 in FIG. 17 and the determination process of step F2 in FIG. 18 are performed by the cell controller. The cell controller is a process when the power is turned on, and the value of the scheduled inspection date and the number of shots scheduled for inspection for each injection molding machine and the current date and the value of the shot number of each injection molding machine stored in the storage means are stored. Then, a regular inspection request signal is output to the injection molding machine that has reached the scheduled inspection date and the number of scheduled inspection shots. The injection molding machine that receives the regular inspection request signal from the cell controller (step G1)
Wait until the operator operates the periodic inspection execution key of the CRT / MDI 119 or operates the periodic inspection release key (steps G2 and G3), and when the operator operates the periodic inspection execution key, the above-mentioned "deterioration state detection" is detected. "Processing" and "deterioration state detection and storage processing" are performed to display a message regarding the deterioration state of each part on the CRT (step G4) and an inspection execution signal is output to the cell controller (step G5). Then, the cell controller receiving the inspection execution signal from the injection molding machine sets the value of the scheduled inspection date and the scheduled shot number of the corresponding injection molding machine stored in the storage means to step E6 or step F6. In the same manner as the process of (1), the data is updated and stored, and the regular inspection request signal to the corresponding injection molding machine is reset.
Further, as in the example shown in FIGS. 17 and 18, when the periodic inspection request signal is not input from the cell controller or when the periodic inspection is postponed by the operator's judgment, the PMC CPU 114 makes steps G4 and G5. Then, the processing is immediately stopped and the processing operation is started based on the same sequence as the conventional one.

In the case of this embodiment, "deterioration state detection processing" and "deterioration state detection storage" are performed by using a condition that injection is performed at a predetermined cylinder temperature using a resin of a specific type without mounting a die. It is also possible to completely automatically start the process related to the periodic inspection by eliminating the need for mounting the mold in the “process”, sealing the nozzle, and operating the injection execution key by the operator.

The above description has been made of the case where the driving means for each axis are all composed of servo motors. However, the driving means for each axis is not limited to a servo motor, but may be an ordinary electric motor or various other known means. Can be used. In general,
An ordinary electric motor is often used in a portion that does not require strict speed control or torque control, such as an injection unit or a mold thickness adjusting section. In such a case, the input / output circuit 107 is used for motor drive control. Simple ON / done via
Since the rotation speed of the motor depends on the OFF control and the rotation speed is constant, it is not necessary to set the speed to regulate the driving condition.

[0088]

The inspection system of the injection molding machine according to the present invention is
The permissible value of the physical quantity when the injection molding machine is driven under the specified conditions is set in advance, and the physical quantity obtained by driving the injection molding machine at the time of inspection of the injection molding machine is within the predetermined permissible value range. Since the deterioration state of each part of the injection molding machine is determined depending on whether or not, it is possible to easily detect the deterioration state of each part by just driving each part of the injection molding machine at the time of regular inspection. You don't have to waste time by performing unnecessary maintenance and readjustment work like this, and you can know this accurately about the parts that require maintenance and adjustment work, which facilitates periodic inspections. Therefore, it is possible to prevent serious damage from occurring.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part of an electric injection molding machine according to an embodiment to which the system of the present invention is applied.

FIG. 2 is a flowchart showing an outline of deterioration state detection processing in one embodiment.

FIG. 3 is a continuation of the flowchart showing the outline of the deterioration state detection processing in the embodiment.

FIG. 4 is a continuation of the flowchart showing the outline of the deterioration state detection processing in the embodiment.

FIG. 5 is a continuation of the flowchart showing the outline of the deterioration state detection processing in the embodiment.

FIG. 6 is a continuation of the flowchart showing the outline of the deterioration state detection processing in the embodiment.

FIG. 7 is a continuation of the flowchart showing the outline of the deterioration state detection processing in the embodiment.

FIG. 8 is a continuation of the flowchart showing the outline of the deterioration state detection processing in the embodiment.

FIG. 9 is a flowchart showing an outline of a permissible value setting storage process in another embodiment.

FIG. 10 is a continuation of the flowchart showing the outline of the allowable value setting storage processing in the embodiment.

FIG. 11 is a continuation of the flowchart showing the outline of the allowable value setting storage processing in the embodiment.

FIG. 12 is a continuation of the flowchart showing the outline of the allowable value setting storage processing in the embodiment.

FIG. 13 is a continuation of the flowchart showing the outline of the allowable value setting storage processing in the embodiment.

FIG. 14 is a flowchart showing a part of deterioration state detection processing in another embodiment.

FIG. 15 is a continuation of the flowchart showing a part of the deterioration state detection processing in the embodiment.

FIG. 16 is a flowchart showing a part of a deterioration state detection storage process of another embodiment.

FIG. 17 is a flowchart showing an outline of a process for determining necessity / non-necessity of regular inspection based on the number of days elapsed since the last regular inspection.

FIG. 18 is a flowchart showing an outline of a process for determining necessity of regular inspection based on the number of shots.

FIG. 19 is a flowchart showing an outline of a process when a periodic inspection is performed by a command from a cell controller that manages an injection molding machine.

[Explanation of symbols]

1 Screw 2 Injection Servo Motor 100 Controller 103 Servo Circuit 105 Shared RAM 111 Servo Interface 112 NC (Numerical Control) CPU 114 PMC (Programmable Machine Controller)
CPU 117 ROM 119 Manual data input device with CRT display device

Claims (4)

[Claims] 1. An allowable value of the physical quantity when the injection molding machine is driven under a predetermined condition is preset with respect to a physical quantity that changes when the injection molding machine is driven, and when the injection molding machine is inspected, The injection molding machine is driven under the predetermined conditions to detect the physical quantity, and the deterioration state of each part of the injection molding machine is determined by whether or not the detected physical quantity is within the predetermined allowable value range. The inspection system of the injection molding machine, which is characterized by 2. The inspection system for an injection molding machine according to claim 1, wherein the physical quantity is a drive current of a motor. 3. The inspection system for an injection molding machine according to claim 1, wherein the physical quantity is an injection pressure. 4. The inspection of the injection molding machine according to claim 1, wherein the allowable value is set based on a physical quantity when the injection molding machine is driven at the time of shipment. method.