JPH04238014A - Drive controlling method of injection molding machine - Google Patents

Abstract

PURPOSE:To simultaneously perform bending and injection molding by a method wherein the bending of thin metal sheet is performed by utilizing the mold clamping force of an injection molding machine. CONSTITUTION:The floating mold 36 of a fixed mold 10 holds a thin metal sheet 41 between the mold and a movable mold 14, and the floating mold 36 is pressingly driven so as to opposedly move relative to a bending mold part 39 in order to carry out bending to the thin metal sheet through the relative movement between the floating mold and the bending mold part. At the time point, when mold clamping completes, the bending is brought to an end. After that, by injecting and filling molten resin, molding process is executed.

Description

[Detailed description of the invention]

0001

0001

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the drive of an injection molding machine equipped with an outsert mold.

0003

0002

0004

[Prior Art] In an injection molding machine that performs outsert molding, the thin metal plate positioned in the mold is previously perforated and bent, and this thin metal plate is used as the fixed side mold. Molten resin is injected into the cavity while the mold is positioned and clamped between the movable mold and a molded product of a predetermined shape is adhered to a thin metal plate.

[0005]

0003

[0006]

[Problems to be Solved by the Invention] As described above, in the prior art, insert molding, for example, of a thin metal sheet for the chassis of an electronic device, usually requires a punching process using a pressing process, followed by a bending process. The pressing process takes time, and the need for a hole-drilling step and a bending step takes up space in the factory.

[0007]

[0004] Therefore, the technical problem to be solved by the present invention is to solve the above-mentioned problems of the prior art.
The purpose of this is to realize a drive control method for an injection molding machine that can reduce overall manufacturing time by bending a thin metal plate during the outsert molding stage of the injection molding machine. .

[0008]

[0005]

[0009]

[Means for Solving the Problems] In order to achieve the above object, the present invention injects molten resin into a cavity while a thin metal plate is positioned and held between a stationary mold and a movable mold. In an injection molding machine, for example, a floating mold is attached to a fixed mold base of a fixed mold, and is biased by a spring in the direction of protruding into the movable mold, and is movable by a predetermined amount against the spring. At the same time, this floating mold fixes the bending mold part that slides relative to each other, and the floating mold and the bending mold are fixed from the time when the release surfaces of the floating mold and the moving mold come into contact with each other during the mold clamping process. In other words, the mold clamping process (
The thin metal plate is bent by the mold clamping force when the mold is closed and retracted, and then molten resin is injected into the cavity.

0010

[0006]

[0011]

[Operation] The movable die on the movable die plate, which is driven by a mold clamping cylinder (hydraulic cylinder) via a toggle link mechanism, is moved from the fixed die base of the fixed die by approximately 7 to 8 mm, for example.
When it reaches a position where it comes into contact with a floating mold spaced apart by about mm, an appropriate sensor detects this. This detection information is recognized by a microcomputer (hereinafter referred to as microcomputer) that controls the operation of the entire machine, and the microcomputer drives and controls the mold clamping cylinder to control the mold clamping stroke during the low-pressure mold clamping control process (on the order of several tons). (mold clamping force) to a high-pressure mold clamping control process to generate a mold clamping force of, for example, about 50 to 60 tons. This high-pressure mold clamping force causes the floating mold to move relative to the bending mold part by being pressed and driven with the thin metal plate sandwiched between it and the movable mold, and between the floating mold and the bending mold. A bending process is performed on the thin metal plate by relative movement with the part. When the floating mold is in close contact with the fixed mold base of the fixed side mold and a predetermined mold clamping force is generated (the toggle link mechanism is stretched and the tie bar is stretched by a predetermined amount), the bending process is performed. After that, the molding process is executed by injecting and filling the molten resin into the cavity.

0012

[0007] By doing so, bending of the metal thin plate and outsert forming can be performed simultaneously, and the total manufacturing time can be shortened.

[0013]

[0008]

[0014]

[Embodiment] The present invention will be explained below with reference to an embodiment shown in FIGS. 1 to 8. Figure 1 is a cross-sectional view of the main parts showing the mold structure during the mold clamping operation (mold closing action), Figure 2 is a cross-sectional view of the main parts showing the mold structure in the completed mold clamping state, and Figure 3 is the entire injection molding machine. A perspective view showing the external appearance, FIG. 4 is an explanatory diagram showing a simplified configuration of the main parts, FIG. 5 is a perspective view of the main parts showing an example of a product after outsert molding, and FIGS. 6 and 7 are bending by mold clamping force. FIG. 8 is an explanatory diagram showing examples of the bending forms to be processed, and FIG. 8 is an operation characteristic diagram showing the relationship between the movable die plate position and mold clamping force.

[0015]

First, the overall configuration will be explained with reference to FIGS. 3 and 4. In FIG. 3, the injection molding machine generally indicated by the reference numeral 1 is integrally equipped with a mold opening/closing system mechanism part 2, an injection system mechanism part 3, a base part 4 containing a control circuit system and a hydraulic control system, etc. In this embodiment, the injection molding machine 1 is additionally equipped with an automatic thin metal sheet insertion/removal device 5, a thin metal sheet supply device 6, a resin material supply device 7, a product conveyor 8, etc. It becomes.

[0016]

The upper left part of FIG. 4 shows the above-mentioned mold opening/closing system mechanism part 2, and as shown in the figure, the mold opening/closing system mechanism part 2 is fixedly installed on the base part 4 and connected to the stationary mold 10. A fixed die plate 9 with a fixed die plate 9 attached thereto, a support plate 11 disposed on the base part 4 so that the position can be adjusted by a predetermined amount, a tie bar 12 installed between the fixed die plate 9 and the support plate 11, and a tie bar 12 inserted through the tie bar 12. A movable die plate 13 to which a movable side mold 14 is attached, a mold clamping cylinder (hydraulic cylinder) 15 which is a driving source for opening and closing the mold, and a toggle link mechanism 16 connected to a piston rod 15a of the mold clamping cylinder 15.
The ejection mechanism is mainly composed of a known ejection mechanism (not shown), its driving source, and the like. Then, as the piston rod 15a of the mold clamping cylinder 15 moves back and forth, the toggle link mechanism 16 is extended or folded in a known manner, and accordingly, the movable die plate 13 is moved back and forth to perform the mold opening/closing operation. It has become. In addition, in the mold opening standby state, a robot hand (not shown) of the automatic insertion/removal device 5 carries the metal thin plate supplied from the metal thin plate supply device 6 to the mold opening space, and transfers this metal thin plate to the fixed side as described later. The robot hand is positioned and attached to the floating mold 36 of the mold 10, after which the robot hand retreats from the mold opening space. Furthermore, after outsert molding,
The robot hand of the automatic insertion/removal device 5 holds the product that is opened and ejected by an eject mechanism (not shown), takes it out of the mold opening space, and places it on the product conveyor 8. It has become.

[0017]

The upper right portion of FIG. 4 shows the injection system mechanism section 3, and as shown in the same figure, the injection system mechanism section 3 includes a heating cylinder 17, a heating cylinder 17 that rotates and rotates back and forth. A screw 18 that is arranged to move freely, a motor (for example, an electric motor) 19 that is a rotational drive source for the screw 18, an injection cylinder (hydraulic cylinder) that also drives and controls the forward and backward movement of the screw 18, and a hopper for supplying raw materials. 21, the above heating cylinder 17
It also mainly consists of a band heater (not shown) wrapped around a nozzle 22 at the tip of the heating cylinder. The resin material supplied from the resin material supply device 7 to the rear part of the heating cylinder 17 via the hopper 15 is
As is known, as the screw 18 rotates, the resin is kneaded and plasticized while being transferred to the distal end of the screw 18 and melted, and as the molten resin is stored on the distal end of the screw 18, the screw 18 retreats while controlling the back pressure. However, the rotation of the screw 18 is stopped when one shot of molten resin is stored at the tip side of the screw 18. Further, when the injection start timing is reached after a predetermined time has elapsed, the screw 18 is driven forward and the cavity (
The molten resin is injected into the molding space.

[0018]

Further, in FIG. 4, reference numeral 23 denotes a microcomputer that controls the operation of the entire machine (injection molding machine 1), and controls the entire molding process such as charging operation, injection operation, mold opening/closing operation, and ejecting operation. or calculation of measured data.
Executes storage processing, etc. This microcomputer 23 actually has various I/O interfaces, ROM, RAM, CP
The molding condition setting storage section 24 and the molding process control section 2 are configured to execute various processes according to various programs prepared in advance.
5, an actual measurement value storage section 26, and an abnormality determination section 27. Note that 28 and 29 are a key input device and a display device including a color CRT display provided in the injection molding machine 1.

[0019]

The molding condition setting storage section 24 stores various operating condition values inputted through the key input device 28 or the like in a rewritable form. These operating condition values include, for example, the relationship between the screw position, screw rotation speed, and back pressure during the charging stroke, suckback control conditions, and injection speed conditions from the injection start point (position) to the holding pressure switching point (position). , secondary injection pressure (holding pressure) conditions from the time of switching to holding pressure to the end of holding pressure, band heater temperature of each part, mold closing (mold clamping) stroke and speed control conditions, mold clamping force, mold opening stroke and speed Examples include control conditions, eject control conditions, and the like.

[0020]

The molding process control unit 25 controls a group of sensors arranged in each part of the injection molding machine 1 based on a molding process control program created in advance and setting condition values stored in the molding condition setting storage unit 24. Driver group 30 (motor driver, hydraulic cylinder driver, heater driver, etc.) while referring to measurement information S1, S2, S3...SN from (position sensors, pressure sensors, etc.) and time information from its own built-in clock. The corresponding drive source is driven and controlled via the controller to execute a series of molding processes. In FIG. 4, S1 is the output signal from the mold clamping force detection sensor 31 that detects the hydraulic pressure (mold clamping force) of the mold clamping cylinder 15, and S2 is the mold opening/closing stroke (position of the movable die plate 13) detection sensor 32. S3 is the output signal from the stationary mold 10.
A mold contact position detection sensor 33 detects the position where the mold release surfaces (parting lines) of the movable mold 14 come into contact with each other.
The output signals from each are shown. Further, D1 indicates a drive signal sent from the driver group 30 to the control valve 34 for controlling the mold clamping cylinder 15.

[0021]

The actual measurement value storage section 26 stores all actual measurement data of preset monitor items during continuous automatic operation over a predetermined number of consecutive shots. The monitor items to be incorporated include ■time monitoring items, ■position monitoring items, ■rotation speed monitoring items, ■speed monitoring items, ■pressure monitoring items, ■temperature monitoring items, and ■power monitoring items. The operating condition setting items almost overlap.

[0022]

The abnormality determination section 27 takes in the data from the molding condition setting storage section 24 and the measured value storage section 26, and refers to the contents of an abnormality determination table (not shown) that has been studied in advance to determine whether an abnormality has occurred. I am constantly monitoring. When the abnormality determination unit 27 recognizes the occurrence of an abnormal situation, it generates an alarm, for example, pulls out message information of the corresponding abnormality item from an alarm message storage unit (not shown), and displays an alarm message on the display device 29. It is forced to display. Furthermore, if the content of the abnormality is determined to be at a predetermined level or higher, a signal indicating this is sent from the abnormality determination unit 27 to the molding process control unit 25, and the molding process control unit 25 causes the machine to stop urgently. It looks like this.

[0023]

Next, a mold structure for outsert molding having a press function according to this embodiment will be explained with reference to FIGS. 1 and 2.

[0024]

In FIGS. 1 and 2, reference numeral 35 indicates a fixed mold base fixedly attached to the fixed die plate 9;
is a floating mold attached to the fixed mold base 35 so as to be able to move back and forth by a predetermined amount, and both 35 and 36 constitute the fixed side mold 10. When the fixed mold 10 and the movable mold 14 are separated from each other as shown in FIG. The mold base 35 is movable by a predetermined amount (approximately 7 to 8 mm in this example) from the fixed mold base 35 by the elastic force of a strong spring 37 (total pressing force of about 10 tons in this example) interposed between the molds. It is placed in a protruding (floating) state in the direction of the side mold 14. Note that the maximum protruding position of the floating mold 36 is determined by the retaining pin 38.

[0025]

Reference numeral 39 denotes a bending mold part fixed to the fixed mold base 35, and the floating mold 36 is slidable with respect to the bending mold part 39, as shown in FIG. When the stationary mold 10 and the movable mold 14 are separated,
A heel-back-shaped protrusion 39a at the tip of the bending mold part 39 projects from the mold release surface of the floating mold 36. 4
0 is a positioning pin attached to the floating mold 36, and a flat metal thin plate (blank) 41 that has been previously drilled and cut into a predetermined outer diameter shape is attached to the positioning pin 40.
The positioning hole is inserted. That is, the robot hand (not shown) of the automatic insertion/extraction device 5 inserts the positioning hole of the thin metal plate 41 into the positioning pin 40, thereby positioning and holding the thin metal plate 41 at a desired position and in a desired posture. It is now possible to
At this time, the bending end surface 39b of the bending mold section 39 is arranged to face the bending area of the thin metal plate 41.

[0026]

Reference numeral 42 denotes a sprue bushing fixed to the fixed mold base 35 side, and a fixed mold base side sprue 43 communicating with a nozzle insertion hole 44 bored in the fixed die plate 9 is formed. 45 is a floating mold side sprue formed on the floating mold 36 side, which includes a runner 46 and a gate 47.
, is connected to the floating mold side cavity 48, and when the mold clamping is completed, which will be described later, this floating mold side sprue 45
communicates with the fixed mold base side sprue 43. Note that the route from the fixed mold base side sprue 43 to the gate 47 is shown in a very simplified manner in this embodiment, but it is obvious to those skilled in the art that this route can be arbitrarily changed in various ways. It is.

[0027]

Reference numerals 49 and 50 denote guide holes drilled in the fixed mold base 35 and the floating mold 36, through which a guide shaft 53 on the movable mold 14 side, which will be described later, can be inserted during mold clamping.

[0028]

On the other hand, the movable mold 14 has a bending mold insertion hole 51 formed in a portion facing the bending mold part 39, and when the mold clamping is completed, as shown in FIG. In the insertion hole 51, along with the bending mold part 39, a part of the thin metal plate 41, which is bent at right angles in the illustrated example, is located. That is, in this embodiment, when the width of the bending die insertion hole 51 is T1, the width of the bending die part 39 is T2, and the thickness of the thin metal plate 41 is t, T1≈T2+t.

[0029]

Furthermore, a guide hole 52 is formed in a portion of the movable mold 14 that faces the positioning pin 40.
When the mold clamping is completed, the positioning pin 40 is positioned within the guide hole 52, as shown in FIG. A guide shaft 53 is fixed and implanted in the movable mold 14, and is inserted into the guide holes 50, 49 of the floating mold 36 and the fixed mold base 35 when mold clamping is completed, as shown in FIG. It has become so.

[0030]

Reference numeral 54 denotes a main cavity formed on the side of the movable mold 14, which communicates with the floating mold side cavity 48 through the through hole 41a of the thin metal plate 41 when the mold clamping is completed.

[0031]

Although not shown, a known eject pin for ejecting the product is inserted into the movable mold 14 and the movable die plate 13 so as to be movable back and forth.
Furthermore, the movable die plate 13 is equipped with an eject plate connected to an eject pin, an eject cylinder that drives the eject plate, etc., but these are omitted for the sake of illustration (these eject mechanisms are based on known mechanisms). Therefore, it is easy to construct for those skilled in the art).

[0032]

The operation based on the above configuration will be explained next. First, in the mold opening standby state after the product from the previous shot has been taken out and a mold release agent has been sprayed on the mold release surface as necessary, a robot hand (not shown) of the automatic insertion/removal device 5 is activated. However, a flat metal thin plate (blank) 41 that has been previously perforated is carried into the mold opening space, and then the positioning hole of the metal thin plate 41 is inserted into the positioning pin 40 of the floating mold 36 described above. , the thin metal plate 41
is positioned and attached onto the floating mold 36. At this time, as described above, the bending end surface 39b of the bending mold part 39 is opposed to the bending area of the thin metal plate 41.

[0033]

Thereafter, when the mold clamping (mold closing) start timing is reached, the microcomputer 23 drives the piston rod 15a of the mold clamping cylinder 15 forward via the control valve 34, thereby causing the toggle link mechanism to move forward. 16, the movable die plate 13 is driven forward in the mold closing direction (in the direction of the arrow in FIG. 1). This mold clamping (mold closing) process is a high-speed mold clamping →
The process is low-pressure mold clamping → high-pressure mold clamping, and the movable mold 14 and floating mold 36 are driven at high speed until they are separated by a predetermined amount, and then low-pressure mold clamping is performed at a predetermined speed. When the mold contact position detection sensor 33 detects that the mold contacting surface of the movable mold 14 and the floating mold 36 have reached a position where they come into contact with each other, the high pressure mold clamping is performed at a predetermined speed. .

[0034]

The movable mold 14 is connected to the spring 37 as described above.
When it reaches the position where it contacts the floating mold 36, which is approximately 7 to 8 mm away from the fixed mold base 35, high-pressure mold clamping that generates a large mold clamping force as described above (for example, the initial pressure of high-pressure mold clamping is 50 tons) is reached. This causes the floating mold 36 to move together with the movable mold 14 against the spring 37.
is driven in the direction of the fixed mold base 35. Floating side mold 3
6 is driven in the above direction, the floating side mold 36 slides with respect to the bending mold part 39, and the bending mold part 39 is connected to the bending mold of the movable side mold 14. Insertion hole 51
gradually enters. By the way, since the thin metal plate 41 is tightly held between the floating mold 36 and the movable mold 14, this relative sliding movement of the floating mold 36 and the movable mold 14 with respect to the bending mold part 39 is prevented. As a result, the thin metal plate portion of the bending mold part 39 facing the bending end surface 39b is pressed by the bending end surface 39b and gradually bent.
It enters the bending mold insertion hole 51.

[0035]

In the mold clamping completed state shown in FIG. 2, the floating mold 36 is in close contact with the fixed mold base 35, and the thin metal plate portion pressed against the bending end surface 39b is completely bent at right angles. Moreover, in this state, a predetermined retightening force is generated. Furthermore, in this state, the fixed mold base side sprue 43 and the floating mold side sprue 45 communicate with each other, and the main cavity 54 formed on the movable mold 14 side and the floating mold side cavity communicate with each other. 4
8 through the through hole 41a of the thin metal plate 41.

[0036]

When the injection start timing is reached after a predetermined time has elapsed after the mold clamping is completed, the screw 18 is driven forward by a command from the microcomputer 23, and the molten resin is poured from the nozzle 22 into the fixed mold. It passes through the base side sprue 43, floating mold side sprue 45, runner 46, and gate 47, and is injected and filled into the floating mold side cavity 48 and the main cavity 54, and then moves to a pressure holding process. As a result, outsert molding is performed in which a molded product of a predetermined shape is attached to the thin metal plate 41. In addition, in FIG. 2, 55 indicates resin.

[0037]

Subsequently, after a cooling stroke for a certain period of time, the microcomputer 23 drives the piston rod 15a of the mold clamping cylinder 15 backward through the control valve 34 to open the mold. An eject mechanism (not shown) is driven during the opening, and the outsert molded product is ejected from the movable mold 14. Then, in synchronization with this ejecting operation, the automatic insertion/removal device 5 is driven, and the robot hand of the device 5 holds the outsert molded product and takes it out from the mold opening space, and transports the product as described above. It is placed on a conveyor 8.

[0038]

FIG. 5 shows an example of a product after outsert molding, and in the same figure, 41b indicates the bent portion of the thin metal plate 41 that has been bent using the mold clamping force as described above. 56 indicates a molded product adhered to and formed on a predetermined portion of the thin metal plate 41.

[0039]

The bent shape to be bent during mold clamping can be variously modified in addition to the above-mentioned L-shaped bending along a straight line.
1b or an embossed bent portion 41b as shown in FIG.

[0040]

FIG. 8 is an operational characteristic diagram showing the relationship between the position of the movable die plate and the mold clamping force. In the figure, the solid line is the characteristic line according to this embodiment, and the broken line is the characteristic line according to the conventional injection molding machine for outsert molding without a press function. In addition, A3, A2, and A1 respectively indicate the high-speed mold clamping area, low-pressure mold clamping area, and high-pressure mold clamping area according to this embodiment, and B3, B2, and B1 represent the high-speed mold clamping area and low-pressure mold clamping area by the conventional injection molding machine. The mold clamping area and high pressure mold clamping area are shown respectively. In addition, P1 is the stroke position where the parting line hits in this embodiment.
2 shows the stroke position where the parting line hits in a conventional injection molding machine.

[0041]

As shown in FIG. 8, in this embodiment, the movable mold 14 comes into contact with the floating mold 36 of the fixed mold 10 mm before the mold clamping completion position, and 2. Low-pressure mold clamping with a mold clamping force of 5 tons was changed to high-pressure mold clamping with a mold clamping force of approximately 50 tons at point P1, which is sufficient to bend the thin metal plate 41. A strong mold clamping force is generated. After point P1, high-pressure mold clamping is performed along a predetermined mold clamping pressure line, and the floating mold 36
After the stroke position where the is in contact with the fixed mold base 35 (
For example, after the P2 point), high-pressure mold clamping continues, and in the mold clamping process after the P2 point, the so-called additional tightening amount (the amount of extension of the tie bar 12) is determined, and the predetermined mold clamping force is ensured when the mold clamping is completed. It is now possible to do so.

[0042]

As is clear from FIG. 8, in this embodiment, the switching point from low-pressure mold clamping to high-pressure mold clamping is considerably farther away from the mold clamping completion position than in the prior art. The switch to high-pressure mold clamping is made at a position where the expansion ratio of the link mechanism 16 is still relatively small. Therefore, when there is a foreign object between the molds, the hydraulic pressure of the mold clamping cylinder 15 shows an abnormality at the beginning of high-pressure mold clamping, and the magnification rate of the toggle link mechanism 16 increases rapidly, causing the mold etc. The abnormality determination unit 27 of the microcomputer 23 before the point where there is a risk of destruction.
It becomes possible for the machine to recognize an abnormality and make an emergency stop of the machine. That is, in this embodiment, detection accuracy and safety are improved when foreign matter is present between the molds.

[0043]

For reference, in this embodiment, there is a strong spring 37 between the fixed mold base 35 and the floating mold 36, so when setting the tightening amount, the fixed mold A rigid spacer is inserted between the base 35 and the floating mold 36 to perform so-called die height adjustment.

[0044]

[0038]

[0045]

[Effects of the Invention] As described above, according to the present invention, since bending can be performed on a thin metal plate at the outsert molding stage using an injection molding machine, it is possible to shorten manufacturing time in total. The industrial value is enormous.

[Brief explanation of the drawing]

[Fig. 1] Mold clamping operation (mold closing operation) according to an embodiment of the present invention
FIG. 3 is a cross-sectional view of the main parts showing the mold structure during the process.

FIG. 2 is a cross-sectional view of a main part showing a mold structure in a state where mold clamping is completed according to an embodiment of the present invention.

FIG. 3 is a perspective view showing the overall appearance of an injection molding machine according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a simplified configuration of main parts of an injection molding machine according to an embodiment of the present invention.

FIG. 5 is a perspective view of a main part showing an example of a product that is outsert molded according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram showing another example of the bending form of a thin metal plate that is bent according to the present invention.

FIG. 7 is an explanatory diagram showing another example of the bending form of a thin metal plate subjected to bending according to the present invention.

FIG. 8 is an operation characteristic diagram showing the relationship between the movable die plate position and mold clamping force according to the embodiment of the present invention in comparison with the conventional technique.

[Explanation of symbols]

1 Injection molding machine 2 Mold opening/closing mechanism part 3 Injection system mechanism part 5 Automatic insertion/extraction device 9 Fixed die plate 10 Fixed side mold 11 Support plate 12 Tie bar 13 Movable die plate 14 Movable side mold 14 15 Mold clamping cylinder 16 Toggle link mechanism 17 Heating cylinder 18 Screw 22 Nozzle 23 Microcomputer 35 Fixed mold base 36 Floating mold 37 Spring 39 Bending mold part 41　Thin metal plate 55 Resin

Claims (5)

[Claims] 1. In an injection molding machine that injects molten resin into a cavity while a thin metal plate is positioned and held between a stationary mold and a movable mold, the thin metal plate is bent using mold clamping force. 1. A drive control method for an injection molding machine, the method comprising: injecting molten resin into the cavity. 2. In claim 1, a mold base of either the stationary mold or the movable mold is biased by a spring in the direction of protruding toward the other mold, and A floating mold that is movable by a predetermined amount is attached, and the bending mold part on which the floating mold slides relative to each other is fixed, so that the floating mold and the other mold are separated from each other during the mold clamping process. A drive control method for an injection molding machine, characterized in that the thin metal plate is bent by relative movement between the floating mold and the bending mold section after the mold surfaces come into contact with each other. 3. The mold opening/closing mechanism according to claim 2, wherein a toggle link mechanism driven by a mold clamping cylinder constituted by a hydraulic cylinder is used, and the mold release surface of the floating mold and the other mold is connected during the mold clamping process. When the two pieces come into contact, the drive by the mold clamping cylinder is switched from low-pressure mold clamping to high-pressure mold clamping, and the floating mold is brought into close contact with the mold base side against the spring by the mold clamping force during high-pressure mold clamping. A drive control method for an injection molding machine characterized by moving the injection molding machine in a direction. 4. In claim 3, when the releasing surfaces of the floating mold and the other mold come into contact during the mold clamping process, the mold clamping force ranges from a low-pressure mold clamping force of about several tons to several tens of tons or more. A drive control method for an injection molding machine, characterized in that the injection molding machine is switched to a high-pressure mold clamping force. 5. In claim 2, the floating mold is provided on the fixed mold, and when the fixed mold base and the floating mold are in close contact with each other, the molten resin flow paths of the two are in communication with each other. A drive control method for an injection molding machine, characterized in that: