JP6935182B2 - Injection molding machine - Google Patents

Description

Embodiments of the present invention relate to injection molding machines.

Conventionally, in an injection molding machine, in order to fill a mold with a molten resin, the molten resin is poured into a cavity inside the mold in an injection process, and the pressure on the molten resin is maintained in a pressure holding step to hold the molten resin in the cavity. Is filled. The injection molding machine controls the speed of the screw in the injection process and controls the pressure of the molten resin in the pressure holding process. In such a switch from the injection process to the pressure holding process, the injection molding machine switched from speed control to pressure control at a preset screw position.

Japanese Unexamined Patent Publication No. 61-229522

However, even if the screw position at the time of switching from speed control to pressure control is set, the difference between the actual pressure at the time of control switching and the pressure command value is large due to the inertial force of the drive system such as the motor and screw. There is. In such a case, the pressure cannot be controlled at the time of control switching, and the machine may be damaged or burrs may occur. For example, the resin pressure may increase as the mold is filled with the molten resin, and may peak near the control switching position. If the injection pressure near this peak cannot be controlled, it may cause defects such as burrs and sink marks.

Therefore, an object of the present invention is to provide an injection molding machine capable of facilitating the control of the pressure of the molten resin and suppressing the occurrence of defects.

The injection molding machine according to the present embodiment is an injection molding machine that molds a product by an injection step of injecting a material into a mold and a pressure holding step of controlling the holding pressure of the material in the mold, and is a barrel for storing the material. Based on the screw that injects material from the barrel to the mold, the setting unit that can set the deceleration start position and screw stop position of the screw in switching from the injection process to the pressure holding process, and the deceleration start position and stop position. It is equipped with a control unit that controls the speed of the screw.

The control unit may be able to set a stop period during which the screw is stopped during switching.

The deceleration start position may be set based on the filling pressure of the material in the injection process.

The stop position may be set based on the filling amount of the material in the injection process.

The injection molding machine according to the present embodiment is an injection molding machine that molds a product by an injection step of injecting a material into a mold and a pressure holding step of controlling the holding pressure of the material in the mold, and is a barrel for storing the material. The screw that injects the material from the barrel to the mold, the deceleration start position of the screw in the switching from the injection process to the pressure holding process, and the speed command of the screw from the time when the screw reaches the deceleration start position to zero. It is provided with a setting unit capable of setting the deceleration command period and a control unit for speed-controlling the screw based on the deceleration start position and the deceleration command period.

The setting unit may be able to set the stop period during which the screw is stopped during switching.

The deceleration start position may be set based on the filling pressure of the material in the injection process.

The control unit may decelerate the speed of the screw at a substantially constant deceleration during switching.

The control unit may change the deceleration of the screw speed in the switching.

The control unit may exponentially reduce the speed of the screw in switching.

The control unit may reduce the speed of the screw in an S-shaped curve at the time of switching.

The control unit may reduce the speed of the screw in switching according to the speed at a preset time point.

The block diagram which shows the structural example of the injection molding machine 1 according to 1st Embodiment. The figure which shows an example of the structure of the control part 8. The graph which shows an example of the operation of an injection molding machine 1. The graph which shows an example of the velocity curve of the injection molding machine 1 according to 2nd Embodiment. The graph which shows an example of the velocity curve of the injection molding machine 1 according to 2nd Embodiment. The graph which shows an example of the velocity curve of the injection molding machine 1 according to 3rd Embodiment.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. The present embodiment is not limited to the present invention.

(First Embodiment)
FIG. 1 is a block diagram showing a configuration example of an injection molding machine 1 according to the first embodiment. The injection molding machine 1 is a machine capable of repeatedly executing a series of injection molding operations. For example, an operation of molding a molded product once is repeated as a cycle operation.

The injection molding machine 1 includes a frame 2, a fixing plate 3, a moving plate 4, a tie bar 5, a mold clamping drive mechanism 6, an injection device 7, a control unit 8, an extrusion mechanism 9, and a human machine. It includes an interface 60, an injection pressure sensor S1, and a screw position sensor S2.

The frame 2 is the base of the injection molding machine 1. The fixing plate 3 is fixed on the frame 2. A fixing mold 11 is attached to the fixing plate 3. One end of the tie bar 5 is fixed to the fixing plate 3, and the other end is fixed to the support plate 10. The tie bar 5 extends from the fixed plate 3 through the moving plate 4 to the support plate 10.

The moving board 4 is mounted on a linear guide (not shown) provided on the frame 2. The moving board 4 can be guided by the tie bar 5 or the linear guide and can move toward or away from the fixed board 3. A moving mold 12 is attached to the moving board 4. The moving mold 12 faces the fixed mold 11, approaches the fixed mold 11 together with the moving plate 4, and is combined with the fixed mold 11. When the moving mold 12 and the fixed mold 11 are brought into contact with each other, a space corresponding to the product shape is formed between the moving mold 12 and the fixed mold 11.

The mold clamping drive mechanism 6 includes a toggle mechanism 13 and a toggle mechanism drive unit 14. The toggle mechanism drive unit 14 includes a mold clamping servomotor 21, a ball screw 22, and a transmission mechanism 23 for driving the toggle mechanism 13. A crosshead 15 is attached to the tip of the ball screw 22. As the ball screw 22 rotates, the crosshead 15 moves so as to approach the moving board 4 or move away from the moving board 4. The transmission mechanism 23 transmits the rotation of the mold clamping servomotor 21 to the ball screw 22 to move the crosshead 15.

When the toggle mechanism drive unit 14 moves the crosshead 15, the toggle mechanism 13 operates. For example, when the crosshead 15 moves toward the moving board 4, the moving board 4 moves toward the fixed board 3 and the mold is closed. On the contrary, when the crosshead 15 moves away from the moving board 4, the moving board 4 moves away from the fixed board 3, and the mold is opened.

The extrusion mechanism 9 includes an extrusion servomotor 71, a ball screw 72, and a transmission mechanism 73 in order to remove the molded product from the moving mold 12. The tip of the ball screw 72 penetrates the inner surface of the moving mold 12. As the ball screw 72 rotates, the ball screw 72 pushes out the product adhering to the inner surface of the moving mold 12. The transmission mechanism 73 transmits the rotation of the extrusion servomotor 71 to the ball screw 72, and moves the ball screw 72 in the left-right direction of FIG.

The injection device 7 includes a heating barrel (band heater) 41, a screw 42, a weighing drive unit 43, and an injection drive unit 44. The heating barrel 41 includes a nozzle 41a for injecting the molten resin into the cavity of the mold. The heating barrel 41 stores the resin from the hopper 45 while heating and melting it, and ejects the molten resin from the nozzle. The screw 42 is provided so as to be movable while rotating or not rotating inside the heating barrel 41. In the weighing step, the screw 42 rotates, and the injection amount of the molten resin injected from the barrel 41 is measured and determined by the rotation amount (moving distance) of the screw 42. In the injection process, the screw 42 moves without rotating and ejects the molten resin from the nozzle.

The weighing drive unit 43 includes a weighing servomotor 46 and a transmission mechanism 47 that transmits the rotation of the weighing servomotor 46 to the screw 42. When the metering servomotor 46 is driven and the screw 42 is rotated in the heating barrel 41, the resin is introduced from the hopper 45 into the heating barrel 41. The introduced resin is sent to the tip end side of the heating barrel 41 while being heated and kneaded. The resin is melted and stored in the tip portion of the heating barrel 41. By moving the screw 42 in the direction opposite to that at the time of weighing, the molten resin is ejected from the barrel 41. At this time, the screw 42 moves without rotating and pushes the molten resin out of the nozzle. In the present embodiment, a molten resin is used as the molding material, but the molding material is not limited to the molten resin, and may be a metal, glass, rubber, a carbonized compound containing carbon fibers, or the like.

The injection drive unit 44 includes an injection servomotor 51, a ball screw 52, and a transmission mechanism 53. As the ball screw 52 rotates, the screw 42 moves in the left-right direction of FIG. 1 in the heating barrel 41. The transmission mechanism 53 transmits the rotation of the injection servomotor 51 to the ball screw 52. As a result, when the injection servomotor 51 rotates, the screw 42 moves. When the screw 42 pushes out the molten resin stored in the tip portion of the heating barrel 41 from the nozzle 41a, the molten resin is ejected from the nozzle 41a.

The injection pressure sensor S1 detects the filling pressure when the molten resin is filled from the barrel 41 to the mold and the holding pressure in the holding pressure step. In the injection process, the injection pressure sensor S1 detects the injection pressure of the molten resin material from the barrel 41 to the mold. In the pressure holding step, the injection pressure sensor S1 detects the pressure holding pressure of the molten resin after the pressure holding is switched from the speed control to the pressure control.

The screw position sensor S2 detects the position of the screw 42. Since the screw 42 moves with the rotation of the injection servomotor 51, the screw position sensor S2 may detect the position of the screw 42 from the rotation speed and the angular position of the injection servomotor 51. By detecting the position of the screw 42 at a predetermined control cycle, the speed and acceleration of the screw 42 can be known.

The human machine interface (HMI / F) 60 displays various information about the injection molding machine 1. The HMI / F60 may include, for example, a display unit and a keyboard, or may be a touch panel display. The user can input settings such as commands related to the operation of the injection molding machine 1 through the HMI / F60. For example, in injection molding, a product is molded by an injection step (speed control) of injecting molten resin into a mold and a pressure holding step (pressure control) of controlling the holding pressure of the molten resin in the mold. In the present embodiment, a pressure holding switching period for maintaining the stop of the screw 42 is provided between the injection process and the pressure holding process. The user can use the moving speed of the screw 42, the speed command deceleration start position (LS4) of the screw 42, the final stop position of the screw 42 (LS4α), or the deceleration start position LS4 of the screw 42 to the stop position (LS4). (The speed command of the screw 42 becomes zero) Each set value such as the deceleration command period ta up to LS4α is input by HMI / F60. The moving speed, deceleration start position, stop position, etc. of the screw 42 can be set by the user based on the actual cycle operation or simulation of the injection molding machine 1. Further, the user may input the speed of the moving mold 12 in the mold clamping step and the mold opening step, the weighing speed in the weighing process, and the like by HMI / F60.

The control unit 8 monitors sensor information received from various sensors (not shown) during the injection process, and controls the injection device 7 based on the sensor information. Further, the control unit 8 controls the screw 42 according to the above-mentioned set value set through the HMI / F60. Further, the control unit 8 causes the display unit 100 to display necessary data.

FIG. 2 is a diagram showing an example of the configuration of the control unit 8. The control unit 8 includes an arithmetic processing unit 61, a setting unit 62, a storage unit 63, an injection device control unit 64, and an input / output unit 65.

The arithmetic processing unit 61 compares the detected values obtained from various sensors such as the pressure sensor and the temperature sensor with the set values stored in the setting unit 62, and compares the temperature of the heating barrel 41, the speed of the screw 42, and the injection pressure. To control. The arithmetic processing unit 61 also controls each component of the control unit 8.

The setting unit 62 stores the information input via the HMI / F60. For example, the setting unit 62 determines the rotation speed of the injection servomotor 51 or the moving speed of the screw 42, the pressure holding pressure in the pressure holding process, the deceleration start position of the screw 42 (LS4), and the final stop position of the screw 42 (LS4α). Alternatively, setting information regarding the deceleration command period (ta) and the like is stored.

The storage unit 63 stores information such as a program for operating the injection molding machine 1, the above set values, and detected values obtained from various sensors.

The injection device control unit 64 controls the drive of the injection servomotor 51. The injection device control unit 64 controls the injection pressure of the injection device 7 by controlling the drive of the injection servomotor 51, for example. The injection device control unit 64 receives feedback from the screw position sensor S2, corrects a position command and a speed command, and controls the injection servomotor 51.

The input / output unit 65 is configured to take in information from the outside to the control unit 8 or output the information of the control unit 8 to the outside. The input / output unit 65 may be connected to another terminal so as to be able to communicate with another terminal by wire or wirelessly.

Next, an operation example in the injection process and the holding pressure switching period of the injection molding machine 1 will be described.

3 (A) to 3 (C) are graphs showing an example of the operation of the injection molding machine 1. The horizontal axis of the graphs of FIGS. 3 (A) to 3 (C) is time. The vertical axes of the graphs of FIGS. 3A to 3C are the position of the screw 42, the speed of the screw 42, and the filling pressure of the molten resin, respectively. The solid line Pa in FIG. 3A indicates the actual position of the lead 42, and the broken line Pb indicates the position command value of the lead 42. The solid line Va in FIG. 3B shows the actual speed of the screw 42, and the broken line Vb shows the speed command value of the screw 42. Hereinafter, the operation of the injection molding machine 1 will be described in chronological order. The position and speed of the screw 42 can be obtained based on the detected value from the screw position sensor S2. The filling pressure can be obtained based on the value detected from the injection pressure sensor S1. Further, it is assumed that the mold clamping process and the molten resin weighing process have already been completed, and the explanation will be started from the injection process.

First, at t0, the injection process is started. At this time, as shown in FIG. 3A, the screw 42 is located at a position separated from the origin 0 by LS5. After that, the screw 42 approaches the origin (the tip of the barrel 41). Here, the actual position Pa of the screw 42 is delayed with respect to the position command value Pb by the amount of the delay due to the feedback control. Therefore, the actual position Pa follows the position command value Pb, but at t0 to t3, it is a position separated from the position command value Pb by approximately (L1-L).

At t0 to t2, the screw 42 is accelerated at a predetermined acceleration as shown in FIG. 3 (B). Here, the actual speed Va of the screw 42 is delayed with respect to the speed command value Vb by the amount of the delay due to the feedback control. Therefore, the actual velocity Va follows the velocity command value Vb, but is displaced with a slight delay from the velocity command value Vb. For example, the speed command value Vb indicates a predetermined speed Vc at t1, but the actual speed Va reaches the predetermined speed Vc at t2.

At t2 to t3, the screw 42 maintains a predetermined speed Vc. After t0, even in this period, the molten resin flows from the barrel 41 into the mold and is filled in the cavity of the mold. When there are still many cavities in the cavities, the filling pressure shown in FIG. 3C changes at a relatively low value. On the other hand, when the number of cavities in the cavity decreases, the filling pressure increases as shown in the vicinity of t3.

At t3, as shown in FIG. 3 (A), when the actual position Pa of the screw 42 reaches the preset deceleration start position LS4, the injection device control unit 64 sets the screw as shown in FIG. 3 (B). Start decelerating 42. As described above, the deceleration start position LS4 can be arbitrarily set by the user. For example, the user may confirm the position of the screw 42 when the filling pressure becomes a predetermined packing pressure Pp by a trial run or a simulation, and set the position as the deceleration start position LS4 in the setting unit 62. At this time, make sure that the peak value Pmax immediately after the packing pressure Pp does not exceed the packing pressure that causes burrs and the like. In this way, the user can set the deceleration start position LS4 based on the packing pressure Pp with reference to the packing pressure Pp close to the peak value Pmax of the filling pressure. This makes it possible to suppress the occurrence of defects such as burrs. The "burr" is a phenomenon in which the molten resin protrudes from the contact surface (parting surface) of the mold due to excessive filling pressure. Further, the stop position LS4α can also be arbitrarily set by the user. For example, since the weight of the molded product is usually fixed, the amount of molten resin to be filled is also fixed. The amount of molten resin to be filled can be converted into the moving distance Ds of the screw 42. Therefore, the stop position LS4α of the screw 42 can be preset by the user.

At t3 to t4, as shown in FIG. 3B, the control unit 8 decelerates the screw 42 and stops the screw 42 at t4. Therefore, at t4, the control unit 8 sets the speed command value Vb to zero. Here, the deceleration start position LS4 and the stop position LS4α are preset. Further, the speed (initial speed Vc) of the screw 42 or the motor 51 at the deceleration start position LS4 can be detected by a position encoder arranged in the motor 51 or the like. The control unit 8 uses the difference between the deceleration start position LS4 and the stop position LS4α (deceleration distance L1) and the initial velocity Vc to set a predetermined acceleration (or) so that the initial velocity Vc of the deceleration start position LS4 becomes zero at the stop position LS4α. Deceleration) α (α = Vc ² / (2 × L1)) can be calculated. Further, the control unit 8 calculates the movement amount (distribution amount) D (D = Vc−α × ts × n) for each sampling period ts when decelerating at the acceleration α, and corresponds to the sampling in each sampling. The motor 51 is controlled by a speed command based on the amount of movement. Note that n is the number of samplings (n = 1 to 2 × L1 / (Vc × ts)) from the deceleration start position LS4 to the stop position LS4α. The control unit 8 decelerates the initial speed Vc of the motor 51 and the screw 42 at the deceleration start position LS4 with the acceleration α, and sets the speed command value of the motor 51 to zero at t4.

At the time of t4, the actual speed Va is not zero because it is delayed with respect to the speed command value Vb. At this time, as shown in FIG. 3A, the position command value Pb of the screw 42 is controlled to be zero at the final stop position LS4α. However, since the actual position Pa is delayed with respect to the position command value Pb, the stop position LS4α has not been reached.

After that, at t5, the actual speed Va of the screw 42 becomes almost zero, and the actual position Pa reaches the stop position LS4α. The control unit 8 may determine that the screw 42 has stopped when the actual speed Va becomes less than a predetermined ratio of the speed at t4. In this way, the command position Pb of the screw 42 stops at the stop position LS4α at t4, and the actual position Pa of the lead 42 stops at the stop position LS4α at t5. As described above, in the present embodiment, the control unit 8 can stop the motor 51 and the screw 42 at the stop position LS4α by speed control.

At t5 to t6, the control unit 8 stops the screw 42 and enters the holding pressure switching period Ts. In the holding pressure switching period Ts as the stop period, the control unit 8 maintains the stopped state of the screw 42. As a result, the molten resin can be sufficiently distributed in the cavity of the mold by utilizing the natural pressure, and molding defects such as sink marks can be suppressed. The “sink” is a phenomenon in which the resin in the cavity of the mold is dented or dented due to a decrease in filling pressure or holding pressure or molding shrinkage.

Ds in FIG. 3A shows the moving distance of the screw 42. Since the cross-sectional area of the barrel 41 is predetermined, the injection amount of the molten resin is uniquely determined based on the moving distance Ds (injection amount = cross-sectional area of the barrel 41 × Ds). That is, it can be said that the moving distance Ds of the screw 42 represents the injection amount.

After t6, the injection device control unit 64 controls the pressure of the screw 42 and enters the pressure holding process. After that, the injection molding machine 1 completes one cycle operation through a cooling step, a weighing step, a mold opening step, an extrusion step, and the like. The injection molding machine 1 may further repeat the same cycle operation.

As described above, in the present embodiment, the deceleration start position LS4 and the stop position LS4α are set by the user. The control unit 8 can calculate the acceleration (deceleration) α from the difference (deceleration distance L1) between the deceleration start position LS4 and the stop position LS4α, and can control the speed of the screw 42 by using the acceleration α. ..

If the speed control is switched to the pressure control when the screw reaches the deceleration start position LS4, the inertial force of the drive system of the screw such as a motor causes the actual pressure at the time of switching from the speed control to the pressure control. The difference from the holding pressure (pressure command) may become large. In this case, braking by pressure control cannot control the pressure, and a sudden increase in pressure may occur, which may cause damage to the machine or generation of burrs.

On the other hand, in the present embodiment, the control unit 8 stops the screw 42 at the stop position LS4α by speed control. After that, the control unit 8 maintains the stopped state of the screw 42 in the holding pressure switching period Ts, reduces the difference between the actual pressure and the holding pressure (pressure command), and then switches from the speed control to the pressure control. As a result, the injection molding machine according to the present embodiment suppresses the difference between the actual pressure and the holding pressure (pressure command) when switching from speed control to pressure control, and suppresses machine damage and the occurrence of burrs. At the same time, it is possible to control the pressure holding pressure in the pressure holding process.

In the present embodiment, the timing for switching from the speed control to the pressure control is t6 when the holding pressure switching period Ts ends. However, the timing of switching from the speed control to the pressure control may be the time t4 when the speed command becomes zero or the time t5 when the screw 42 actually stops. The holding pressure switching period Ts can be arbitrarily set by the user.

The time point t5 when the screw 42 actually stops is smaller than the time point t4 when the speed command becomes zero in terms of the difference between the actual pressure and the holding pressure (pressure command) (see FIG. 3C). Therefore, it is preferable that the control unit 8 switches from the speed control to the pressure control at the time point t5 rather than the time point t4. In this case, the holding pressure switching period Ts becomes almost zero. The time point t5 is after the delay period tb has elapsed from the time point t4.

The delay period tb (t4 to t5) of the actual velocity Va with respect to the velocity command value Vb is determined by using the reciprocal of the position loop gain ω0 and is expressed by Equation 1. The delay period tb is uniquely determined by the position loop gain ω0.
tb = 1 / ω0 (Equation 1)
The control unit 8 may calculate Equation 1 and switch from speed control to pressure control after the lapse of ta + tb from the deceleration start time t3. As described above, in the present embodiment, the timing for switching from the speed control to the pressure control may be a time point t4 after the delay time tb elapses from a time point t4 when the speed command becomes almost zero.

(Modification example)
In the first embodiment, the deceleration start position LS4 and the stop position LS4α are set as parameters that can be set by the user. The control unit 8 controls the screw 42 based on these parameters.

On the other hand, in this modification, the user sets the deceleration start position LS4 and the deceleration command period ta. In this case, the control unit 8 calculates the actual deceleration distance L1 (L1 = Vc / (2 × ta)) based on the deceleration command period ta, the deceleration start position LS4, and the initial speed Vc. The deceleration distance L1 corresponds to the area of the shaded area SL in FIG. 3 (B). The sum of the deceleration start position LS4 and the deceleration distance L1 is the stop position LS4α. Using the deceleration distance L1 and the initial velocity Vc, the calculation unit 8 uses the acceleration (or deceleration) α (α = Vc ² / (2 × L1)) and the movement amount for each sampling period ts, as in the first embodiment. (Distribution amount) D (D = Vc-α × ts × n) can be calculated. As a result, the control unit 8 of this modification can stop the motor 51 and the screw 42 at the stop position LS4α by speed control. Therefore, this modification can also obtain the same effect as that of the first embodiment.

In the above embodiment, the holding pressure switching period Ts as the stop period of the screw 42 may be variable in the holding pressure switching period. In this case, the user can set the holding pressure switching period Ts via the HMI / F60. For example, when the stop period (restraint period) of the screw 42 is set to almost zero, the holding pressure switching period Ts may be set to zero. In this case, the injection molding machine 1 starts the pressure holding step from the stop time t5 of the screw 42.

(Second Embodiment)
In the first embodiment, the deceleration α of the screw 42 during the deceleration command period ta is substantially constant. On the other hand, in the second embodiment, the deceleration of the screw 42 is made variable. Thereby, the curve of the filling pressure can be made into a desired curve.

4 and 5 are graphs showing an example of the speed curve of the injection molding machine 1 according to the second embodiment. For example, as shown in t3 to t4 of FIG. 4, the control unit 8 may exponentially reduce the speed command Vb. The setting parameters (time point and speed setting) of the exponential function may be stored in the storage unit 63 in advance. Further, as shown in t3 to t4 of FIG. 5, the control unit 8 may reduce the speed command Vb in an S shape. The setting parameters of the S-shaped curve may also be stored in the storage unit 63 in advance.

(Third Embodiment)
FIG. 6 is a graph showing an example of the speed curve of the injection molding machine 1 according to the third embodiment. The third embodiment is similar to the second embodiment in that the deceleration of the screw 42 is made variable. However, in the third embodiment, the user can arbitrarily set the speed and time. For example, as shown in t3 to t4 of FIG. 6, the user sets the speed of the screw 42 to be Vs1 at the time point ts1, sets the speed of the screw 42 to be Vs2 at the time point ts2, and sets the speed of the screw 42 to Vs2. The speed of the screw 42 is set to Vs3, and the speed of the screw 42 is set to Vs4 at the time point ts4. These setting parameters are stored in the storage unit 63. The control unit 8 reduces the speed command Vb according to the setting parameters stored in the storage unit 63.

In this way, the curve (trajectory) of the filling pressure in the holding pressure switching period can be made into a desired curve by allowing the user to arbitrarily set the setting parameters of the time and the speed. As a result, the injection molding machine 1 according to the third embodiment can handle various molding materials and dies. The number of time points and the number of speeds that can be set are not limited to four, and may be more or less. Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Injection molding machine, 7 ... Injection device, 8 ... Control unit, 60 ... Human machine interface, S1 ... Injection pressure sensor, S2 ... Screw position sensor

Claims (10)

An injection molding machine that molds a product by an injection step of injecting a material into a mold and a pressure holding step of controlling the holding pressure of the material in the mold.
The barrel that stores the material and
A screw that ejects the material from the barrel to the mold,
A setting unit capable of setting the deceleration start position of the screw, the stop position of the screw, and the stop period of the screw in switching from the injection process to the pressure holding process.
The deceleration of the screw is calculated from the difference between the set deceleration start position of the screw and the stop position of the screw, and the speed of the screw is controlled by using the deceleration.
The delay period obtained by calculating the delay of the screw with respect to the speed command of the speed control, and the delay period.
The set stop period and
After passing
An injection molding machine including a control unit that executes the pressure holding step. The injection molding machine according to claim 1 , wherein the deceleration start position is set based on the filling pressure of the material in the injection step. The injection molding machine according to claim 1 or 2 , wherein the stop position is set based on the filling amount of the material in the injection step. An injection molding machine that molds a product by an injection step of injecting a material into a mold and a pressure holding step of controlling the holding pressure of the material in the mold.
The barrel that stores the material and
A screw that ejects the material from the barrel to the mold,
The deceleration start position of the screw in the switching from the injection process to the pressure holding process, the deceleration command period from when the screw reaches the deceleration start position until the speed command of the screw becomes zero, and the stop period of the screw. With the setting part that can set
The deceleration distance of the screw is calculated based on the set deceleration start position and the deceleration command period, the deceleration of the screw is calculated using the deceleration distance, and the speed control of the screw is performed using the deceleration. death,
The delay period obtained by calculating the delay of the screw with respect to the speed command, and
The set stop period and
After passing
An injection molding machine including a control unit that executes the pressure holding step. The injection molding machine according to claim 4 , wherein the deceleration start position is set based on the filling pressure of the material in the injection step. The injection molding machine according to any one of claims 1 to 5 , wherein the control unit decelerates the speed of the screw at a substantially constant deceleration in the switching. The injection molding machine according to any one of claims 1 to 5 , wherein the control unit changes the deceleration of the speed of the screw in the switching. The injection molding machine according to claim 7 , wherein the control unit exponentially reduces the speed of the screw in the switching. The injection molding machine according to claim 7 , wherein the control unit reduces the speed of the screw in an S-shaped curve in the switching. The injection molding machine according to claim 7 , wherein the control unit reduces the speed of the screw according to a preset time point in the switching.

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