JP7455640B2 - Injection molding machine - Google Patents

Description

The present disclosure relates to injection molding machines.

For example, an injection molding machine is known in which an injection device is electrically driven and a mold clamping device is hydraulically driven (see Patent Document 1).

Patent No. 5921736

By the way, there is a demand for a compact injection molding machine.

Therefore, in view of the above problems, it is an object of the present invention to provide a compact injection molding machine.

In order to achieve the above object, an embodiment of the present disclosure includes a fixed platen to which a fixed mold is attached, a movable platen to which a movable die is attached, a hydraulic cylinder that moves the movable platen forward and backward, and an ejector rod that moves the ejector rod back and forth. an ejector device, the piston portion of the hydraulic cylinder has a housing portion, at least some components of the ejector device are disposed in the housing portion , and the ejector device has a screw shaft; A screw nut that is threadedly engaged with a screw shaft, and the screw shaft moves forward and backward as the screw nut rotates, and has a supply path for supplying lubricant between the screw shaft and the screw nut. The lubricant is supplied from the tip of the screw shaft to the transfer surface of the screw shaft and the screw nut via the supply path, and includes a discharge path that communicates the accommodating portion with the outside of the accommodating portion. An injection molding machine is provided.

According to the embodiments described above, a compact injection molding machine can be provided.

FIG. 1 is a diagram showing an example of an injection molding machine. FIG. 1 is a diagram showing an example of an injection molding machine. It is a figure showing an example of a mold clamping device. It is a figure showing an example of a mold clamping device. It is a figure showing an example of a mold clamping device. It is a figure showing an example of a mold clamping device. It is a sectional view showing an example of an ejector device. FIG. 7 is a partially enlarged sectional view showing another example of the ejector device.

Embodiments will be described below with reference to the drawings.

[Injection molding machine configuration]
<Injection molding machine>
FIG. 1 is a diagram illustrating a state of an injection molding machine according to an embodiment when mold opening is completed. FIG. 2 is a diagram showing a state of the injection molding machine according to one embodiment during mold clamping. In this specification, the X-axis direction, the Y-axis direction, and the Z-axis direction are directions perpendicular to each other. The X-axis direction and the Y-axis direction represent the horizontal direction, and the Z-axis direction represents the vertical direction. When the mold clamping device 100 is a horizontal type, the X-axis direction is the mold opening/closing direction, and the Y-axis direction is the width direction of the injection molding machine 10. The negative side in the Y-axis direction is called the operation side, and the positive side in the Y-axis direction is called the counter-operation side.

As shown in FIGS. 1 and 2, the injection molding machine 10 includes a mold clamping device 100 that opens and closes the mold device 800, an injection device 300 that injects molding material into the mold device 800, and It has a moving device 400 that moves the injection device 300 forward and backward, a control device 700 that controls each component of the injection molding machine 10, and a frame 900 that supports each component of the injection molding machine 10. Injection molding machine 10 also includes an ejector device 200 that ejects a molded product molded by mold device 800 from mold device 800 (movable mold 820). Frame 900 includes a mold clamping device frame 910 that supports mold clamping device 100 and an injection device frame 920 that supports injection device 300. The mold clamping device frame 910 and the injection device frame 920 are each installed on the floor 2 via a leveling adjuster 930. The control device 700 is arranged in the interior space of the injection device frame 920. Each component of the injection molding machine 10 will be explained below.

<Mold clamping device>
In the description of the mold clamping device 100, the moving direction of the movable platen 120 when the mold is closed (for example, the X-axis positive direction) is referred to as the front, and the moving direction of the movable platen 120 when the mold is opened (for example, the X-axis negative direction) is referred to as the rear. do.

The mold clamping device 100 performs mold closing, pressurization, mold clamping, depressurization, and mold opening of the mold device 800. The mold device 800 includes a fixed mold 810, a movable mold 820, and a movable member 830 that is disposed inside the movable mold 820 (hollow portion) so as to be movable forward and backward.

The mold clamping device 100 is, for example, horizontal, and the mold opening/closing direction is horizontal. The mold clamping device 100 includes a fixed platen 110, a movable platen 120, a tie bar 140, a hydraulic cylinder (hydraulic cylinder) 150, and the like.

Fixed platen 110 is fixed to mold clamping device frame 910. A fixed mold 810 is attached to a surface of the fixed platen 110 facing the movable platen 120.

The movable platen 120 is arranged to be movable in the mold opening/closing direction with respect to the mold clamping device frame 910. A guide 101 for guiding the movable platen 120 is installed on the mold clamping device frame 910. A movable mold 820 is attached to a surface of the movable platen 120 facing the fixed platen 110. By moving the movable platen 120 forward and backward relative to the fixed platen 110, the mold device 800 is closed, pressurized, clamped, depressurized, and opened.

The tie bar 140 connects the fixed platen 110 and the cylinder body 151 (see FIGS. 3 to 6) of the hydraulic cylinder 150 at a distance L in the mold opening/closing direction. A plurality of tie bars 140 (for example, four) may be used. The plurality of tie bars 140 are arranged parallel to the mold opening/closing direction, and expand according to the mold clamping force.

Hydraulic cylinder 150 is attached to the movable platen. The hydraulic cylinder 150 drives the movable platen 120 using a so-called direct pressure type, and moves the movable platen 120 in the mold opening/closing direction. Details of the configuration of the hydraulic cylinder 150, its drive mechanism, and its operation will be described later (see FIGS. 3 to 6).

The mold clamping device 100 performs a mold closing process, a pressure increasing process, a mold clamping process, a depressurizing process, a mold opening process, etc. under the control of the control device 700. Specific operations of the mold clamping device 100 corresponding to these steps will be described later (see FIGS. 3 to 6).

In the mold closing process, the movable platen 120 is advanced and the movable mold 820 is fixed by driving the hydraulic cylinder 150 to advance the hydraulic cylinder 150 (piston portion 152 described later) at a set movement speed to a mold closing completion position. Touch the mold 810. The position and moving speed of the hydraulic cylinder 150 are detected using, for example, a cylinder sensor. The cylinder sensor detects the extended/contracted position of the hydraulic cylinder 150 and sends a signal indicating the detection result to the control device 700. As a result, the control device 700 performs feedback control regarding the position of the hydraulic cylinder 150 (movable platen 120) (position control of the hydraulic cylinder 150) based on a signal indicating the detection result of the cylinder sensor in the mold clamping process and the mold opening process described below. )It can be performed.

Note that the hydraulic cylinder position detector that detects the position of the hydraulic cylinder 150 and the hydraulic cylinder movement speed detector that detects the moving speed of the hydraulic cylinder 150 are not limited to cylinder sensors, and general ones can be used.

In the pressure increase step, the hydraulic cylinder 150 is further driven to control the pressure of the hydraulic cylinder 150 to a predetermined pressure (hereinafter referred to as "target mold clamping pressure"), and by increasing the pressure of the hydraulic cylinder 150, mold clamping is performed. generate force. The pressure of the hydraulic cylinder 150 is detected using, for example, a pressure sensor (cylinder pressure sensor) provided in the hydraulic cylinder 150. The cylinder pressure sensor detects the pressure of a predetermined oil chamber inside the hydraulic cylinder 150 (for example, the oil chamber 155 described below) and sends a signal indicating the detection result to the control device 700. As a result, the control device 700 performs feedback control regarding the pressure of the hydraulic cylinder 150 (pressure control of the hydraulic cylinder 150) based on a signal indicating the detection result of the cylinder pressure sensor in the pressure increase process and the mold clamping process and depressurization process described later. )It can be performed.

In the mold clamping process, the hydraulic cylinder 150 is driven to maintain the pressure of the hydraulic cylinder 150 at the target mold clamping pressure. In the mold clamping process, the mold clamping force generated in the pressure increasing process is maintained. In the mold clamping process, a cavity space 801 (see FIG. 2) is formed between the movable mold 820 and the fixed mold 810, and the injection device 300 fills the cavity space 801 with liquid molding material. A molded article is obtained by solidifying the filled molding material.

The number of cavity spaces 801 may be one or more. In the latter case, multiple molded articles can be obtained simultaneously. An insert material may be placed in a part of the cavity space 801, and another part of the cavity space 801 may be filled with a molding material. A molded product in which the insert material and the molding material are integrated can be obtained.

In the depressurization step, the mold clamping force is reduced by driving the hydraulic cylinder 150 to reduce the target mold clamping pressure.

In the mold opening process, the movable platen 120 is retreated by driving the hydraulic cylinder 150 (piston portion 152) at a set movement speed from the mold opening start position to the mold opening completion position. 820 is separated from the fixed mold 810. Thereafter, the ejector device 200 ejects the molded product from the movable mold 820. The mold opening start position and the mold closing completion position may be the same position.

Setting conditions in the mold closing process, pressure increasing process, and mold clamping process are collectively set as a series of setting conditions. For example, the moving speed, position (including the mold closing start position, movement speed switching position, mold closing completion position, and mold clamping position), and pressure (including the target mold clamping pressure) of the hydraulic cylinder 150 in the mold closing process and the pressure increasing process , mold clamping force, etc. are collectively set as a series of setting conditions. The mold closing start position, the movement speed switching position, the mold closing completion position, and the mold clamping position are arranged in this order from the rear side toward the front, and represent the start and end points of the section in which the movement speed is set. A moving speed is set for each section. There may be one or more moving speed switching positions. The moving speed switching position does not need to be set. Any one or only two of the mold clamping position, target mold clamping pressure, and mold clamping force may be set.

Setting conditions in the depressurization process and mold opening process are similarly set. For example, the moving speed and position (mold opening start position, moving speed switching position, and mold opening completion position) of the hydraulic cylinder 150 in the depressurization process and the mold opening process are collectively set as a series of setting conditions. The mold opening start position, the moving speed switching position, and the mold opening completion position are arranged in this order from the front side toward the rear, and represent the starting point and ending point of the section in which the moving speed is set. A moving speed is set for each section. There may be one or more moving speed switching positions. The moving speed switching position does not need to be set. The mold opening start position and the mold closing completion position may be the same position. Further, the mold opening completion position and the mold closing start position may be the same position.

Note that instead of the moving speed, position, etc. of the hydraulic cylinder 150, the moving speed, position, etc. of the movable platen 120 may be set. Furthermore, instead of the position of the hydraulic cylinder 150 (for example, the mold clamping position) or the position of the movable platen 120, a target mold clamping pressure or mold clamping force may be set.

Although the mold clamping device 100 of this embodiment is a horizontal type in which the mold opening/closing direction is the horizontal direction, it may be a vertical type in which the mold opening/closing direction is the vertical direction.

<Ejector device>
In the description of the ejector device, similar to the description of the mold clamping device 100, the moving direction of the movable platen 120 when closing the mold (for example, the The negative axis direction) will be explained as being backward.

The ejector device is attached to the movable platen 120 and moves forward and backward together with the movable platen 120. The ejector device includes an ejector rod that ejects the molded product from the mold device 800, and a drive mechanism that moves the ejector rod in the moving direction of the movable platen 120 (X-axis direction).

The ejector rod comes into contact with a movable member 830 that is disposed within the movable mold 820 so as to be movable back and forth, and can move the movable member forward.

The drive mechanism includes, for example, an ejector motor and a motion conversion mechanism that converts rotational motion of the ejector motor into linear motion of the ejector rod. The motion conversion mechanism includes a screw shaft and a screw nut that is threaded onto the screw shaft. A ball or roller may be interposed between the screw shaft and the screw nut.

The ejector device performs the ejecting process under the control of the control device 700. In the ejecting process, the ejector device advances the movable member 830 to eject the molded product.

The position and moving speed of the ejector rod are detected using, for example, an ejector motor encoder. The ejector motor encoder detects the rotation of the ejector motor and sends a signal indicating the detection result to the control device 700. Further, the ejector rod position detector that detects the position of the ejector rod and the ejector rod movement speed detector that detects the moving speed of the ejector rod are not limited to the ejector motor encoder, and general ones can be used.

<Injection device>
In the description of the injection device 300, unlike the description of the mold clamping device 100 and the ejector device 200, the direction of movement of the screw 330 during filling (for example, the negative direction of the X axis) is referred to as the front, and the direction of movement of the screw 330 during metering is (For example, the X-axis positive direction) will be explained as being backward.

The injection device 300 is installed on a slide base 301, and the slide base 301 is arranged to be movable forward and backward relative to the injection device frame 920. The injection device 300 is arranged to be movable forward and backward relative to the mold device 800. The injection device 300 touches the mold device 800 and fills the cavity space 801 in the mold device 800 with the molding material. The injection device 300 includes, for example, a cylinder 310, a nozzle 320, a screw 330, a metering motor 340, an injection motor 350, a pressure detector 360, and the like.

The cylinder 310 heats the molding material supplied therein from the supply port 311 . The molding material includes, for example, resin. The molding material is formed into a pellet shape, for example, and is supplied to the supply port 311 in a solid state. The supply port 311 is formed at the rear of the cylinder 310 . A cooler 312 such as a water-cooled cylinder is provided on the outer periphery of the rear portion of the cylinder 310 . A heater 313 such as a band heater and a temperature detector 314 are provided on the outer periphery of the cylinder 310 in front of the cooler 312 .

The cylinder 310 is divided into a plurality of zones in the axial direction (for example, the X-axis direction) of the cylinder 310. A heater 313 and a temperature detector 314 are provided in each of the plurality of zones. A set temperature is set for each of the plurality of zones, and the control device 700 controls the heater 313 so that the temperature detected by the temperature detector 314 becomes the set temperature.

The nozzle 320 is provided at the front end of the cylinder 310 and is pressed against the mold device 800. A heater 313 and a temperature detector 314 are provided on the outer periphery of the nozzle 320. The control device 700 controls the heater 313 so that the detected temperature of the nozzle 320 becomes the set temperature.

The screw 330 is arranged within the cylinder 310 so as to be rotatable and movable back and forth. When the screw 330 is rotated, the molding material is sent forward along the spiral groove of the screw 330. The molding material is gradually melted by heat from the cylinder 310 while being sent forward. As the liquid molding material is sent forward of the screw 330 and accumulated at the front of the cylinder 310, the screw 330 is retracted. Thereafter, when the screw 330 is moved forward, the liquid molding material accumulated in front of the screw 330 is injected from the nozzle 320 and filled into the mold device 800.

A backflow prevention ring 331 is attached to the front of the screw 330 so that it can move forward and backward as a backflow prevention valve that prevents the molding material from flowing backward from the front of the screw 330 when the screw 330 is pushed forward.

When the screw 330 is advanced, the backflow prevention ring 331 is pushed backward by the pressure of the molding material in front of the screw 330, and is moved relative to the screw 330 to a closed position (see FIG. 2) where it blocks the flow path of the molding material. fall back. This prevents the molding material accumulated in front of the screw 330 from flowing backward.

On the other hand, when the screw 330 is rotated, the backflow prevention ring 331 is pushed forward by the pressure of the molding material sent forward along the spiral groove of the screw 330, and is moved to an open position where the flow path of the molding material is opened. (see FIG. 1) relative to the screw 330. As a result, the molding material is sent to the front of the screw 330.

The backflow prevention ring 331 may be either a co-rotating type that rotates together with the screw 330 or a non-co-rotating type that does not rotate together with the screw 330.

Note that the injection device 300 may include a drive source that moves the backflow prevention ring 331 forward and backward relative to the screw 330 between an open position and a closed position.

Metering motor 340 rotates screw 330. The drive source for rotating the screw 330 is not limited to the metering motor 340, and may be, for example, a hydraulic pump.

The injection motor 350 moves the screw 330 forward and backward. A motion conversion mechanism or the like that converts the rotational motion of the injection motor 350 into linear motion of the screw 330 is provided between the injection motor 350 and the screw 330. The motion conversion mechanism includes, for example, a screw shaft and a screw nut that is threaded onto the screw shaft. A ball, roller, etc. may be provided between the screw shaft and the screw nut. The drive source for advancing and retracting the screw 330 is not limited to the injection motor 350, and may be, for example, a hydraulic cylinder.

Pressure detector 360 detects the force transmitted between injection motor 350 and screw 330. The detected force is converted into pressure by the control device 700. The pressure detector 360 is provided in a force transmission path between the injection motor 350 and the screw 330, and detects the force acting on the pressure detector 360.

Pressure detector 360 sends a signal indicating the detection result to control device 700. The detection results of the pressure detector 360 are used to control and monitor the pressure that the screw 330 receives from the molding material, the back pressure on the screw 330, the pressure that acts on the molding material from the screw 330, and the like.

The injection device 300 performs a metering process, a filling process, a pressure holding process, etc. under the control of the control device 700. The filling process and the pressure holding process may be collectively referred to as the injection process.

In the metering process, the screw 330 is rotated at a set rotation speed by driving the metering motor 340, and the molding material is sent forward along the spiral groove of the screw 330. Along with this, the molding material is gradually melted. As the liquid molding material is sent forward of the screw 330 and accumulated at the front of the cylinder 310, the screw 330 is retracted. The rotational speed of the screw 330 is detected using, for example, a metering motor encoder 341. Measuring motor encoder 341 detects the rotation of metering motor 340 and sends a signal indicating the detection result to control device 700. Further, the screw rotation speed detector for detecting the rotation speed of the screw 330 is not limited to the metering motor encoder 341, and a general type can be used.

In the metering process, the injection motor 350 may be driven to apply a set back pressure to the screw 330 in order to limit rapid retraction of the screw 330. The back pressure against the screw 330 is detected using, for example, a pressure detector 360. Pressure detector 360 sends a signal indicating the detection result to control device 700. When the screw 330 is retracted to the metering completion position and a predetermined amount of molding material is accumulated in front of the screw 330, the metering process is completed.

The position and rotational speed of the screw 330 in the metering process are set together as a series of setting conditions. For example, a measurement start position, a rotational speed switching position, and a measurement completion position are set. These positions are lined up in this order from the front to the rear, and represent the start and end points of the section in which the rotational speed is set. The rotation speed is set for each section. The number of rotational speed switching positions may be one or more. The rotational speed switching position does not need to be set. Further, back pressure is set for each section.

In the filling process, the injection motor 350 is driven to advance the screw 330 at a set moving speed, and the liquid molding material accumulated in front of the screw 330 is filled into the cavity space 801 in the mold device 800. The position and moving speed of the screw 330 are detected using, for example, an injection motor encoder 351. Injection motor encoder 351 detects rotation of injection motor 350 and sends a signal indicating the detection result to control device 700. When the position of the screw 330 reaches the set position, the filling process is switched to the pressure holding process (so-called V/P switching). The position where V/P switching is performed is also called the V/P switching position. The set moving speed of the screw 330 may be changed depending on the position of the screw 330, time, etc.

The position and movement speed of the screw 330 in the filling process are collectively set as a series of setting conditions. For example, a filling start position (also referred to as an "injection start position"), a moving speed switching position, and a V/P switching position are set. These positions are lined up in this order from the rear to the front, and represent the start and end points of the section in which the moving speed is set. A moving speed is set for each section. There may be one or more moving speed switching positions. The moving speed switching position does not need to be set.

The upper limit value of the pressure of the screw 330 is set for each section in which the moving speed of the screw 330 is set. The pressure of the screw 330 is detected by a pressure detector 360. When the detected value of the pressure detector 360 is less than or equal to the set pressure, the screw 330 is moved forward at the set moving speed. On the other hand, if the detected value of the pressure detector 360 exceeds the set pressure, the screw 330 moves at a slower moving speed than the set moving speed so that the detected value of the pressure detector 360 becomes less than the set pressure in order to protect the mold. will be advanced.

In addition, after the position of the screw 330 reaches the V/P switching position in the filling process, the screw 330 may be temporarily stopped at the V/P switching position, and then the V/P switching may be performed. Immediately before the V/P switching, instead of stopping the screw 330, the screw 330 may be moved forward or backward at a very slow speed. Further, the screw position detector that detects the position of the screw 330 and the screw movement speed detector that detects the moving speed of the screw 330 are not limited to the injection motor encoder 351, and general ones can be used.

In the pressure holding process, the injection motor 350 is driven to push the screw 330 forward, and the pressure of the molding material at the front end of the screw 330 (hereinafter also referred to as "holding pressure") is maintained at the set pressure, and the pressure inside the cylinder 310 is maintained. The remaining molding material is pushed toward the mold apparatus 800. Insufficient molding material due to cooling shrinkage within the mold device 800 can be replenished. The holding pressure is detected using a pressure detector 360, for example. Pressure detector 360 sends a signal indicating the detection result to control device 700. The set value of the holding pressure may be changed depending on the elapsed time from the start of the pressure holding process. A plurality of holding pressures and a plurality of holding times for holding the holding pressure in the pressure holding step may be set, and may be set all at once as a series of setting conditions.

In the pressure holding process, the molding material in the cavity space 801 in the mold device 800 is gradually cooled, and when the pressure holding process is completed, the entrance of the cavity space 801 is closed with the solidified molding material. This state is called a gate seal, and backflow of the molding material from the cavity space 801 is prevented. After the pressure holding process, a cooling process is started. In the cooling process, the molding material within the cavity space 801 is solidified. A metering step may be performed during the cooling step to reduce molding cycle time.

Although the injection device 300 of this embodiment is of an in-line screw type, it may also be of a pre-plastic type. A pre-plastic injection device supplies a molding material melted in a plasticizing cylinder to an injection cylinder, and injects the molding material from the injection cylinder into a mold device. Inside the plasticizing cylinder, a screw is arranged so as to be rotatable but not moveable, or a screw is arranged so as to be rotatable and move back and forth. On the other hand, a plunger is arranged within the injection cylinder so that it can move forward and backward.

Moreover, although the injection device 300 of this embodiment is a horizontal type in which the axial direction of the cylinder 310 is horizontal, it may be a vertical type in which the axial direction of the cylinder 310 is vertical. The mold clamping device combined with the vertical injection device 300 may be vertical or horizontal. Similarly, the mold clamping device combined with the horizontal injection device 300 may be horizontal or vertical.

Thus, in this embodiment, the injection device 300 is electrically driven by electric actuators such as the metering motor 340 and the injection motor 350. Thereby, the injection device 300 can relatively improve responsiveness to the control command from the control device 700 compared to the case where the injection device 300 is hydraulically driven. Therefore, the injection molding machine 10 can achieve relatively excellent controllability of the injection device 300.

<Mobile device>
In the description of the moving device 400, similarly to the description of the injection device 300, the direction of movement of the screw 330 during filling (for example, the negative direction of the X-axis) is referred to as the front, and the direction of movement of the screw 330 during metering (for example, the positive direction of the X-axis) is referred to as the front. will be explained as backward.

The moving device 400 moves the injection device 300 forward and backward relative to the mold device 800. Furthermore, the moving device 400 presses the nozzle 320 against the mold device 800 to generate nozzle touch pressure. The moving device 400 includes a hydraulic pump 410, a motor 420 as a drive source, a hydraulic cylinder 430 as a hydraulic actuator, and the like.

Hydraulic pump 410 has a first port 411 and a second port 412. The hydraulic pump 410 is a bidirectionally rotatable pump, and by switching the rotation direction of the motor 420, the hydraulic pump 410 sucks in hydraulic fluid (for example, oil) from one of the first port 411 and the second port 412 and discharges it from the other. to generate hydraulic pressure. Further, the hydraulic pump 410 can also suck the hydraulic fluid from the tank and discharge the hydraulic fluid from either the first port 411 or the second port 412.

Motor 420 operates hydraulic pump 410. The motor 420 drives the hydraulic pump 410 in a rotational direction and rotational torque according to a control signal from the control device 700. Motor 420 may be an electric motor or an electric servo motor.

The hydraulic cylinder 430 has a cylinder body 431, a piston 432, and a piston rod 433. The cylinder body 431 is fixed to the injection device 300. The piston 432 partitions the inside of the cylinder body 431 into a front chamber 435 as a first chamber and a rear chamber 436 as a second chamber. Piston rod 433 is fixed relative to fixed platen 110.

The front chamber 435 of the hydraulic cylinder 430 is connected to the first port 411 of the hydraulic pump 410 via the first flow path 401 . The injection device 300 is pushed forward by the hydraulic fluid discharged from the first port 411 being supplied to the front chamber 435 via the first flow path 401. The injection device 300 is advanced and the nozzle 320 is pressed against the fixed mold 810. The front chamber 435 functions as a pressure chamber that generates nozzle touch pressure of the nozzle 320 by the pressure of the working fluid supplied from the hydraulic pump 410.

On the other hand, the rear chamber 436 of the hydraulic cylinder 430 is connected to the second port 412 of the hydraulic pump 410 via the second flow path 402 . The injection device 300 is pushed rearward by the hydraulic fluid discharged from the second port 412 being supplied to the rear chamber 436 of the hydraulic cylinder 430 via the second flow path 402. The injection device 300 is moved back, and the nozzle 320 is separated from the fixed mold 810.

Note that in this embodiment, the moving device 400 includes a hydraulic cylinder 430, but the present invention is not limited thereto. For example, instead of the hydraulic cylinder 430, an electric motor and a motion conversion mechanism that converts the rotational motion of the electric motor into linear motion of the injection device 300 may be used.

<Control device>
The control device 700 is composed of, for example, a computer, and includes a CPU (Central Processing Unit) 701, a storage medium 702 such as a memory, an input interface 703, and an output interface 704, as shown in FIGS. The control device 700 performs various controls by causing the CPU 701 to execute programs stored in the storage medium 702. Further, the control device 700 receives a signal from the outside through an input interface 703, and transmits a signal to the outside through an output interface 704.

The control device 700 controls the molded product by repeatedly performing a measuring process, a mold closing process, a pressurizing process, a mold clamping process, a filling process, a pressure holding process, a cooling process, a depressurizing process, a mold opening process, an ejecting process, etc. Manufacture repeatedly. A series of operations for obtaining a molded product, for example, from the start of a metering process to the start of the next metering process, is also called a "shot" or a "molding cycle." The time required for one shot is also called "molding cycle time" or "cycle time."

One molding cycle includes, for example, a measuring process, a mold closing process, a pressure increasing process, a mold clamping process, a filling process, a pressure holding process, a cooling process, a depressurizing process, a mold opening process, and an ejecting process in this order. The order here is the starting order of each step. The filling process, pressure holding process, and cooling process are performed during the mold clamping process. The start of the mold clamping process may coincide with the start of the filling process. The end of the depressurization process coincides with the start of the mold opening process.

Note that a plurality of steps may be performed simultaneously for the purpose of shortening the molding cycle time. For example, the metering step may be performed during the cooling step of the previous molding cycle, or during the clamping step. In this case, the mold closing step may be performed at the beginning of the molding cycle. Also, the filling process may be started during the mold closing process. Also, the ejection process may be started during the mold opening process. If an on-off valve is provided to open and close the flow path of the nozzle 320, the mold opening process may be started during the metering process. This is because even if the mold opening process is started during the metering process, if the on-off valve closes the flow path of the nozzle 320, the molding material will not leak from the nozzle 320.

In addition, one molding cycle includes processes other than the measuring process, mold closing process, pressure increase process, mold clamping process, filling process, pressure holding process, cooling process, depressurization process, mold opening process, and ejection process. It's okay.

For example, after the pressure holding process is completed and before the measurement process is started, a pre-measurement suckback process may be performed in which the screw 330 is retreated to a preset measurement start position. The pressure of the molding material accumulated in front of the screw 330 before the start of the metering process can be reduced, and rapid retraction of the screw 330 at the start of the metering process can be prevented.

Further, after the completion of the measurement process and before the start of the filling process, a post-measurement suck-back process may be performed in which the screw 330 is retreated to a preset filling start position (also referred to as "injection start position"). The pressure of the molding material accumulated in front of the screw 330 before the start of the filling process can be reduced, and leakage of the molding material from the nozzle 320 before the start of the filling process can be prevented.

The control device 700 is connected to an operating device 750 that accepts input operations by a user and a display device 760 that displays a display screen. The operating device 750 and the display device 760 may be configured with a touch panel, for example, and may be integrated. The touch panel as the display device 760 displays a display screen under the control of the control device 700. Information such as the settings of the injection molding machine 10 and the current state of the injection molding machine 10 may be displayed on the display screen of the touch panel. Furthermore, the display screen of the touch panel may display input operation units such as buttons and input fields for accepting input operations by the user, for example. The touch panel as the operating device 750 detects an input operation by the user on the display screen, and outputs a signal corresponding to the input operation to the control device 700. As a result, for example, the user can operate the input operation section provided on the display screen while checking the information displayed on the display screen to set the injection molding machine 10 (including inputting setting values), etc. It can be carried out. Further, by the user operating an input operation section provided on the display screen, the injection molding machine 10 can be caused to perform an operation corresponding to the input operation section. Note that the operation of the injection molding machine 10 may be, for example, the operation (including stopping) of the mold clamping device 100, the ejector device 200, the injection device 300, the moving device 400, and the like. Further, the operation of the injection molding machine 10 may be switching of a display screen displayed on a touch panel serving as the display device 760.

Note that although the operating device 750 and the display device 760 of this embodiment have been described as being integrated as a touch panel, they may be provided independently. Further, a plurality of operating devices 750 may be provided. The operating device 750 and the display device 760 are arranged on the operating side (Y-axis negative direction) of the mold clamping device 100 (more specifically, the fixed platen 110).

[Details of mold clamping device]
Next, details of the mold clamping device 100 will be described with reference to FIGS. 3 to 6 in addition to FIGS. 1 and 2.

3 to 6 are diagrams showing an example of the mold clamping device 100 according to this embodiment. Specifically, FIGS. 3 to 6 are diagrams showing the operating states of the mold clamping device 100 in each of a mold closing process, a pressure increase process, a mold clamping process, a depressurization process, and a mold opening process.

Note that the drawing of the mold device 800 is omitted in FIGS. 3 to 6.

<Configuration of mold clamping device>
As shown in FIGS. 3 to 6, the mold clamping device 100 includes a fixed platen 110, a movable platen 120, a tie bar 140, a hydraulic cylinder 150, a hydraulic circuit 160, and a servo motor 170.

Hydraulic cylinder 150 includes a cylinder body portion 151 , a piston portion 152 , a rod portion 153 , and a cylinder closing portion 154 .

The cylinder main body portion 151 is a fixed portion of the hydraulic cylinder 150. The cylinder body 151 is connected to the other end of the tie bar 140, which has one end connected to the fixed platen 110. Thereby, the distance between the cylinder body portion 151 and the fixed platen 110 is fixed at a constant distance (distance L). The cylinder main body 151 is provided with a hollow portion whose front end (end in the negative direction of the X-axis) is open.

One of the cylinder main body portion 151 and the fixed platen 110 connected via the tie bar 140 is fixed to the mold clamping device frame 910, and the other is movably mounted on the mold clamping device frame 910. This allows the tie bars 140 to stretch due to the generation of mold clamping force.

One end of the piston portion 152 is inserted into the interior (hollow portion) of the cylinder body portion 151, and the other end is fixed to the movable platen 120. As a result, the piston portion 152 can move in the front-rear direction (X direction) under the action of the hydraulic oil supplied to and discharged from the cylinder body portion 151, and as a result, the movable platen 120 fixed to one end of the piston portion 152 can move back and forth. It can be moved in the direction (X direction). Further, the piston portion 152 is provided with a hollow portion that is open to the inside of the cylinder body portion 151.

One end of the rod portion 153 is fixed to the closed end (that is, the end in the negative X-axis direction) of the hollow portion of the cylinder body portion 151, and the other end is inserted into the hollow portion of the piston portion 152. Thereby, the rod portion 153 can move the piston portion 152 forward (in the positive direction of the X-axis) by the action of hydraulic oil supplied to the hollow portion (oil chamber 157 described below) of the piston portion 152. Further, the rod portion 153 is provided with a hole portion that extends in the axial direction from the other end side that is inserted into the hollow portion of the piston portion 152 .

The cylinder closing portion 154 closes the open end of the cylinder body portion 151. The cylinder closing portion 154 is provided with a through hole through which the piston portion 152 can move forward and backward.

Further, inside the hydraulic cylinder 150, oil chambers 155 to 157 are provided.

The oil chamber 155 is defined by the inner wall of the cylinder body 151 and the tip (one end) of the piston 152 at the closed end (end in the negative X-axis direction) of the hollow portion of the cylinder body 151. provided. Thereby, the piston portion 152 can apply mold clamping force to the movable platen 120 by the action of the hydraulic oil supplied to the oil chamber 155. The oil chamber 155 is provided with a port 155P for supplying and discharging hydraulic oil.

The oil chamber 156 has a shape defined by an inner wall of the cylinder body 151, an inner wall of the cylinder closing portion 154, and an intermediate portion of the piston portion 152 at the open end (end in the X-axis positive direction) of the cylinder body 151. Established in Thereby, the piston portion 152 can move backward (that is, move in the negative direction of the X-axis) by the action of the hydraulic oil supplied to the oil chamber 156. The oil chamber 156 is provided with a port 156P for supplying and discharging hydraulic oil.

The oil chamber 157 is defined by the inner wall of the hollow portion of the piston portion 152 and the tip portion of the rod portion 153. Thereby, the piston portion 152 can move forward (that is, move in the positive direction of the X-axis) by the action of the hydraulic oil supplied to the oil chamber 157. The oil chamber 157 communicates with a hole in the rod portion 153, and a port 157P for supplying and discharging hydraulic oil to and from the oil chamber 157 is provided at the tip of the hole in the rod portion 153.

Hydraulic circuit 160 drives hydraulic cylinder 150. Hydraulic circuit 160 includes a hydraulic pump 161, a hydraulic tank 162, stop valves 163 to 165, a prefill valve 166, and oil passages OL1 to OL4.

The hydraulic pump 161 supplies hydraulic oil to the hydraulic cylinder 150 and discharges the hydraulic oil from the hydraulic cylinder 150. Hydraulic pump 161 is driven by servo motor 170. The hydraulic pump 161 is configured to be able to discharge hydraulic oil from one of the ports 161P1 and 161P2 and suck hydraulic oil from the other by switching the rotation direction of the servo motor 170. Further, the hydraulic pump 161 is connected to a hydraulic tank 162 through an oil path OL1, and can replenish hydraulic oil from the hydraulic tank 162 or discharge hydraulic oil to the hydraulic tank 162.

Port 161P1 is connected to ports 155P and 157P through oil path OL2. Specifically, oil passage OL2 is branched into oil passages OL2A and OL2B. Port 161P1 is connected to port 155P, ie, oil chamber 155, through oil path OL2A, and connected to port 157P, ie, oil chamber 157, through oil path OL2B. Thereby, the hydraulic pump 161 can supply hydraulic oil to at least one of the oil chamber 155 and the oil chamber 157 by discharging the hydraulic oil from the port 161P1.

Port 161P2 is connected to port 156P, that is, oil chamber 156, through oil passage OL3. Thereby, the hydraulic pump 161 can supply hydraulic oil to the oil chamber 156 by discharging the hydraulic oil from the port 161P2.

The hydraulic pump 161 and the servo motor 170 may be housed in an integrated housing, for example, as an integrated drive unit (hereinafter referred to as a "pump unit") (see FIGS. 7 to 10). Thereby, the arrangement of the hydraulic pump 161 and the servo motor 170 can be consolidated and the size can be reduced.

Hydraulic pump 161 and hydraulic tank 162 may be connected by, for example, a steel pipe. That is, the oil passage OL1 may be realized by a steel pipe. Similarly, the hydraulic pump 161 and the cylinder main body 151 may be connected by, for example, a steel pipe. That is, the oil passage OL2 (oil passage OL2A, OL2B) and the oil passage OL3 may be realized by steel pipes. This makes it possible to suppress deterioration over time and relatively lengthen maintenance cycles such as replacement and repair, compared to, for example, the case where the oil passages OL1 to OL3 are realized by rubber pipes or the like.

When at least one of the oil passages OL1 to OL3 is realized by a steel pipe, the fixed platen 110 and the cylinder body part 151 of the cylinder body part 151 are fixed to the mold clamping device frame 910, and the fixed platen 110 is fixed to the mold clamping device frame 910. It may be movably placed on the top. This is because the fixed platen 110 moves on the mold clamping device frame 910, and as described above, it is possible to allow the tie bars 140 to expand due to the mold clamping force. Furthermore, if the cylinder body 151 were to be moved, it would be necessary to move heavy items such as steel pipes corresponding to the oil passages OL1 to OL3 and the hydraulic pump 161 (pump unit) connected by the steel pipes, which would be wasteful. This is because there is a possibility that a large amount of energy will be consumed. Furthermore, it is possible to prevent a situation in which load is accumulated on the steel pipe connecting between the cylinder body 151 and the hydraulic pump 161 due to movement of the cylinder body 151, shortening its life span or causing damage. This is because it can be done.

The hydraulic tank 162 (an example of a tank) stores hydraulic oil. Hydraulic tank 162 is connected to hydraulic pump 161 through oil path OL1. Further, the hydraulic tank 162 is connected to the port 155P, that is, the oil chamber 155 through the oil path OL4. As shown in FIGS. 1 and 2, the hydraulic tank 162 is arranged adjacent to the hydraulic cylinder 150 in the width direction (Y-axis direction).

The hydraulic tank 162 may be directly attached to the cylinder body 151 via a prefill valve 166, for example. That is, the oil passage OL4 is disposed within the housing of the prefill valve 166, which is integrated with the hydraulic tank 162 and the cylinder body 151. Further, the hydraulic tank 162 may be connected by, for example, a steel pipe. That is, the oil passage OL4 may be realized by a steel pipe. Thereby, for example, compared to the case where the oil passage OL4 is realized by a rubber pipe or the like, deterioration over time can be suppressed and maintenance cycles such as replacement and repair can be made relatively longer. Moreover, in the former case, the cylinder main body 151, the hydraulic tank 162, and the prefill valve 166 can be integrated. Therefore, the hydraulic circuit 160 and the servo motor 170 can be made smaller.

When the hydraulic tank 162 is directly attached to the cylinder body 151 via the prefill valve 166, or when the oil passage OL4 is realized by a steel pipe, the cylinder body of the fixed platen 110 and the cylinder body 151, as described above. 151 may be fixed to the mold clamping device frame 910, and the fixed platen 110 may be movably mounted on the mold clamping device frame 910. This produces the same effects and effects as described above.

The stop valve 163 is provided in the oil passage OL2A. The stop valve 163 switches the oil passage OL2A between a communicating state and a blocking state under the control of the control device 700. Thereby, the stop valve 163 can supply the hydraulic oil discharged from the port 161P1 of the hydraulic pump 161 only to the oil chamber 157 through the oil path OL2B, for example, by blocking the oil path OL2A.

Stop valve 164 is provided in oil passage OL2B. The stop valve 164 switches the oil passage OL2B between a communicating state and a blocking state under the control of the control device 700. Thereby, the stop valve 164 can supply the hydraulic oil discharged from the port 161P1 of the hydraulic pump 161 only to the oil chamber 155 through the oil path OL2A, for example, by blocking the oil path OL2B. Further, the stop valve 164 can maintain the hydraulic oil in the oil chamber 157 by, for example, blocking the oil passage OL2B.

Stop valve 165 is provided in oil passage OL3. The stop valve 165 switches the oil passage OL3 between a communicating state and a blocking state under the control of the control device 700. Thereby, the stop valve 165 can, for example, shut off the oil passage OL3, thereby discharging the hydraulic oil sucked into the hydraulic pump 161 from the port 161P1 into the hydraulic tank 162 without discharging it from the port 161P2. I can do it.

The following description will proceed on the assumption that the stop valves 163 to 165 are normally open (ie, normally open) and are closed in response to a control command from the control device 700.

Prefill valve 166 is provided in oil path OL4. The prefill valve 166 is normally closed (ie, normally closed), and is opened in response to pilot pressure supplied from a pilot line (not shown) branching from the oil path OL3.

Servo motor 170 operates under the control of control device 700. Thereby, the control device 700 can control the operation of the hydraulic pump 161 by controlling the servo motor 170.

The control device 700 controls the flow of hydraulic oil in the hydraulic circuit 160 by controlling the hydraulic pump 161 (servo motor 170) and the stop valves 163 to 165, and controls the mold closing process, pressure increasing process, and mold clamping process by the mold clamping device 100. Realizes the tightening process, depressurization process, and mold opening process.

Thus, in this embodiment, the mold clamping device 100 is hydraulically driven by the hydraulic cylinder 150. Specifically, the hydraulic cylinder 150 drives the movable platen 120 using a so-called direct pressure type. Thereby, the mold clamping device 100 can have a shorter dimension in the X direction than in the case of a so-called toggle type. Therefore, the size of the injection molding machine 10 can be reduced.

Furthermore, in this embodiment, the hydraulic circuit 160 that hydraulically drives the mold clamping device 100 (hydraulic cylinder 150) is configured as a closed circuit.

If the hydraulic circuit 160 is an open circuit, the hydraulic circuit 160 needs to be provided with a direction switching valve for switching the direction in which hydraulic oil flows. Further, the hydraulic circuit 160 needs to be provided with a hydraulic tank 162 having a relatively large capacity. This is because all the hydraulic oil for the hydraulic circuit 160 needs to be supplied from the hydraulic tank 162. Therefore, the size of the hydraulic circuit 160 increases, and there is a possibility that its components cannot be arranged only in the vicinity of the hydraulic cylinder 150 to be driven. Therefore, for example, it may be necessary to arrange a hydraulic tank or the like in the space below the mold device 800. As a result, it becomes impossible for the user to arrange a conveyance device or the like for receiving the molded product ejected from the mold device 800 by the ejector device 200 in the space under the mold device 800 and conveying it to another location. may become less convenient.

In contrast, in this embodiment, the hydraulic circuit 160 is configured as a closed circuit, so that the size of the hydraulic circuit 160 can be reduced and its components can be concentrated in a location adjacent to the hydraulic cylinder 150. Specifically, as described above, the hydraulic tank 162 can be placed adjacent to the hydraulic cylinder 150 (see FIGS. 1 and 2). Further, as will be described later, a pump unit including a hydraulic pump 161, a servo motor 170, etc. can be placed adjacent to the hydraulic cylinder 150. Therefore, for example, it is not necessary to arrange the components of the hydraulic circuit 160 in the space below the mold device 800, and user convenience can be improved.

<Operation of mold clamping device>
In the mold closing process, the control device 700 outputs a control command to the stop valve 163 to close the stop valve 163. As a result, the oil passage OL2A of the oil passages OL2A and OL2B is placed in a blocked state.

Further, the control device 700 outputs a control command to the servo motor 170 and operates the hydraulic pump 161 to discharge hydraulic oil from the port 161P1. As a result, as shown in FIG. 3, the hydraulic pump 161 sucks hydraulic oil from the oil passage OL3, discharges the hydraulic oil from the oil chamber 156, and discharges the hydraulic oil to the oil passage OL2B. Hydraulic oil can be supplied to the oil chamber 157. Therefore, the hydraulic cylinder 150 extends in such a manner that the piston portion 152 protrudes forward from the hollow portion of the cylinder body portion 151, and the piston portion 152 (movable platen 120) moves from the mold closing start position to the mold closing completion position.

In the pressure increasing process and the mold clamping process, the control device 700 outputs a control command to the stop valve 164 to close the stop valve 164. As a result, the oil passage OL2B of the oil passages OL2A and OL2B is placed in a blocked state, and the hydraulic oil in the oil chamber 157 is maintained.

Further, the control device 700 outputs a control command to the servo motor 170 and operates the hydraulic pump 161 to discharge hydraulic oil from the port 161P1. Thereby, as shown in FIG. 4, the hydraulic pump 161 can discharge hydraulic oil to the oil passage OL2A and supply the hydraulic oil to the oil chamber 155 through the oil passage OL2A.

Furthermore, at the start of the pressure increase process, a predetermined pilot pressure acts on the prefill valve 166 from the above-mentioned pilot line due to the action of the hydraulic oil flowing through the oil path OL3 during the mold clamping process, and the prefill valve 166 is opened. ing. Further, at the start of the pressure increasing process, the oil chamber 155 is in a negative pressure state. Therefore, as shown in FIG. 4, hydraulic oil is supplied from the hydraulic tank 162 to the oil chamber 155 through the oil path OL4.

Due to the action of the hydraulic oil supplied to the oil chamber 155, the piston portion 152 further protrudes forward from the hollow portion of the cylinder body portion 151, and the hydraulic cylinder 150 further extends. Therefore, the piston portion 152 (movable platen 120) further moves from the mold closing completion position to the mold clamping position to generate mold clamping force, and is maintained at the mold clamping position.

In the depressurization step, the control device 700 outputs a control command to the stop valves 164 and 165 to close the stop valves 164 and 165. As a result, the oil passage OL2B of the oil passages OL2A and OL2B is placed in a blocked state, and the hydraulic oil in the oil chamber 157 is maintained. Further, the oil passage OL3 can be placed in a blocked state to prevent hydraulic oil from flowing into the oil chamber 156.

Further, the control device 700 outputs a control command to the servo motor 170, and operates the hydraulic pump 161 to suck hydraulic oil from the port 161P1. As a result, as shown in FIG. 5, the hydraulic pump 161 sucks hydraulic oil from the oil passage OL2A, discharges the hydraulic oil from the oil chamber 155, and discharges the hydraulic oil into the hydraulic tank 162 through the oil passage OL1 ( Discharge. Therefore, the mold clamping force generated by the action of the hydraulic oil in the oil chamber 155 is gradually reduced, and the piston portion 152 (movable platen 120) returns from the mold clamping position to the mold opening start position (mold closing completion position).

In the mold opening process, the control device 700 outputs a control command to the stop valve 163 to close the stop valve 163. As a result, the oil passage OL2A of the oil passages OL2A and OL2B is placed in a blocked state.

Further, the control device 700 outputs a control command to the hydraulic pump 161, and operates the hydraulic pump 161 to suck hydraulic oil from the port 161P1 and discharge hydraulic oil from the port 161P2. As a result, as shown in FIG. 6, the hydraulic pump 161 sucks hydraulic oil from the oil passage OL2B, discharges the hydraulic oil from the oil chamber 157, and discharges the hydraulic oil to the oil passage OL3, and discharges the hydraulic oil from the oil chamber 156. Supply hydraulic oil. Further, the hydraulic pump 161 replenishes hydraulic oil from the hydraulic tank 162 through the oil path OL1. Therefore, the hydraulic cylinder 150 contracts in such a manner that the piston portion 152 is inserted into the hollow portion of the cylinder body portion 151, and the piston portion 152 (movable platen 120) moves from the mold opening start position to the mold opening completion position.

Further, due to the action of the hydraulic oil flowing through the oil passage OL3, a predetermined pilot pressure acts on the prefill valve 166 from the above-mentioned pilot line, and the prefill valve 166 is opened. Therefore, as the hydraulic cylinder 150 contracts, the hydraulic oil remaining in the oil chamber 155 is discharged to the hydraulic tank 162 through the oil path OL4.

As described above, in the present embodiment, the mold clamping device 100 is hydraulically driven by the hydraulic cylinder 150 for all operations related to the mold closing process, the pressure increasing process, the mold clamping process, the depressurizing process, and the mold opening process.

For example, if the operations related to the pressure increase process, mold clamping process, and depressurization process are hydraulically driven, and the operations related to the mold opening process and mold closing process are electrically driven, there is a concern that the configuration of the mold clamping device 100 will become complicated. Ru.

On the other hand, in the present embodiment, the mold clamping device 100 hydraulically drives operations related to all processes using the hydraulic cylinder 150, thereby making it possible to simplify the components. Therefore, the size of the mold clamping device 100 can be reduced.

[Details of ejector device]
Next, details of the ejector device 200 will be described with reference to FIG. 7.

FIG. 7 is a sectional view showing an example of the ejector device 200 according to this embodiment. Specifically, FIG. 7 is a diagram showing a state in which the ejector rod 210 is retracted into the movable platen 120.

The ejector device 200 includes an ejector rod 210, a ball screw shaft 220, a ball screw nut 230, a bearing 240, a driven pulley 250, a timing belt 260, a drive pulley (not shown), and an ejector motor (not shown). ) and a pulley housing 270.

The ejector rod 210 is provided so as to be able to move forward and backward from the hole 121 of the movable platen 120. As the ejector rod 210 moves forward, the front end of the ejector rod 210 comes into contact with the movable member 830 (see FIG. 1), allowing the movable member to move forward.

A coupling portion 211 is provided at the rear end of the ejector rod 210 to be detachably coupled to the ball screw shaft 220. For example, a female thread is formed in the coupling part 211 and is screwed into a male thread formed in the ball screw shaft 220. Thereby, the ejector rod 210 is coupled to the ball screw shaft 220.

Furthermore, a coupling portion 212 for coupling a shaft member (not shown) used when extending the ejector rod 210 may be provided at the front end of the ejector rod 210. For example, a female thread may be formed in the coupling portion 212, and the coupling portion 212 may be threadedly engaged with a male thread formed in the shaft member. Thereby, the length of the ejector rod 210 can be extended by coupling the shaft member to the ejector rod 210.

The ball screw shaft 220 is screwed into a ball screw nut 230. Further, the ball screw shaft 220 is prevented from rotating by an ejector crosshead 224. Thereby, the ball screw shaft 220 and the ball screw nut 230 constitute a motion conversion mechanism that converts the rotational motion of the ball screw nut 230 into linear motion of the ball screw shaft 220. That is, as the ball screw nut 230 rotates, the ball screw shaft 220 moves in the axial direction.

The bearing 240 rotatably supports the ball screw nut 230. Here, a housing portion 158 is formed on the tip side of the piston portion 152 (on the front side of the oil chamber 157). The outer ring of the bearing 240 fits into the housing portion 158 and is prevented from coming off by a spacer 241. Further, the inner ring of the bearing 240 is fitted with the ball screw nut 230 and is prevented from coming off by a lock nut 242 that is screwed into the ball screw nut 230. This restricts movement of the ball screw nut 230 in the axial direction.

In this way, at least a portion of the ejector device 200 is disposed in the accommodating portion 158 formed on the distal end side of the piston portion 152. Specifically, the motion conversion mechanism (ball screw shaft 220, ball screw nut 230) and bearing 240 are arranged in the housing portion 158. Note that the rear side of the motion conversion mechanism (ball screw shaft 220, ball screw nut 230) is arranged in the housing section 158, and the front side of the motion conversion mechanism (ball screw shaft 220, ball screw nut 230) is arranged at the tip of the piston section 152. It may be placed before.

The driven pulley 250 is fixed to the front side of the ball screw nut 230 with a bolt 255. Further, a drive pulley (not shown) is fixed to a rotating shaft of an ejector motor (not shown). The driving pulley and the driven pulley 250 are connected by a timing belt 260.

With this configuration, by operating the ejector motor, the ball screw nut 230 rotatably supported by the bearing 240 rotates via the drive pulley, the timing belt 260, and the driven pulley 250. The rotational movement of the ball screw nut 230 is converted into a linear movement of the ball screw shaft 220 that is threadedly engaged with the ball screw nut 230. The linear movement of the ball screw shaft 220 causes the ejector rod 210 to move forward and backward.

The pulley housing 270 has a substantially cylindrical shape, is disposed between the piston section 152 and the movable platen 120, and is fixed to the piston section 152 and the movable platen 120. Specifically, a bolt hole (not shown) is formed in the distal end surface of the piston portion 152. The rear side of the spacer 241 is fitted into the accommodating part 158 of the piston part 152, and the front side of the spacer 241 is fitted with the pulley housing 270, so that they are positioned coaxially. Then, the spacer 241 is sandwiched between the front end surface of the piston portion 152 and the rear surface of the pulley housing 270, and the pulley housing 270 is fixed from inside with bolts 272. Further, by fitting the movable platen 120 and the pulley housing 270, they are positioned coaxially. The movable platen 120 and the pulley housing 270 are fixed with bolts (not shown). With such a configuration, when the piston portion 152 moves in the front-rear direction (X direction), both the pulley housing 270 and the movable platen 120 also move in the front-rear direction (X direction). Note that the nut 141 adjusts the distance between the fixed platen 110 and the cylinder body 151 of the hydraulic cylinder 150, which are connected by the tie bar 140.

The substantially cylindrical pulley housing 270 has its front side closed by the movable platen 120 and its rear side closed by the piston part 152, thereby forming an accommodating part 271 inside the pulley housing 270. The driven pulley 250 is arranged in the accommodating portion 271 of the pulley housing 270 . Further, the housing portion 271 of the pulley housing 270, the housing portion 158 of the piston portion 152, and the hole portion 121 of the movable platen 120 are in communication with each other. Note that the movable platen 120 may be provided with a recessed portion.

Additionally, a drive pulley (not shown) and an ejector motor (not shown) may be located outside the pulley housing 270. For example, the ejector motor may be fixed to the side surface (including the top and bottom surfaces) of the movable platen 120. The timing belt 260 passes through an opening (not shown) provided in a pulley housing 270 and connects a driven pulley 250 disposed inside the pulley housing 270 and a driving pulley (not shown) disposed outside the pulley housing 270. z).

Here, the axial length of the piston portion 152 is determined based on the movable range (platen stroke) of the movable platen 120 when opening and closing the mold. Further, a hollow portion (oil chamber 157) is formed from the rear end side of the piston portion 152. Therefore, the distal end side of the piston portion 152 has a region in which a hollow portion (oil chamber 157) is not formed. Further, the axial lengths of the ball screw shaft 220 and the ball screw nut 230 are determined based on the movable range (ejector stroke) of the ejector rod 210. In the ejector device 200 of the present embodiment, a housing portion 158 is provided on the distal end side of the piston portion 152 to accommodate at least a portion of the components of the ejector device 200. With such a configuration, the overall length of the mold clamping device 100 can be shortened while ensuring the platen stroke and ejector stroke. That is, the injection molding machine 10 can be made compact.

In the ejector device 200 shown in FIG. 7, the explanation has been made assuming that the ball screw nut 230 rotates and the ball screw shaft 220 moves in the front-rear direction, but the present invention is not limited to this. The ball screw nut may be fixed to the accommodating portion 158 of the piston portion 152, and the ball screw shaft may be rotated. Even in such a configuration, by accommodating at least a portion of the components of the ejector device 200, the overall length of the mold clamping device 100 can be shortened while ensuring the platen stroke and the ejector stroke. That is, the injection molding machine 10 can be made compact.

Further, in the ejector device 200 of this embodiment, it is preferable that a bearing 240 is attached to the ball screw nut 230. That is, in the motion conversion mechanism, the ball screw nut 230 rotates, and the ball screw shaft 220 moves forward and backward in the axial direction. Here, in a configuration in which the ball screw nut is fixed to the housing portion 158 of the piston portion 152 and the ball screw shaft rotates, a mechanism for preventing rotation transmission between the rotating ball screw shaft and the ejector rod (for example, , thrust bearing). Therefore, the total length of the ejector device 200 is increased. In contrast, in the ejector device 200 of this embodiment, the ejector rod 210 can be directly attached to the ball screw shaft 220 that moves back and forth in the axial direction. Thereby, the overall length of the mold clamping device 100 can be shortened. That is, the injection molding machine 10 can be made compact.

Furthermore, in the ejector device 200 of the present embodiment, the drive pulley (not shown) and the ejector motor (not shown) are preferably arranged radially outward from the piston portion 152. In other words, the axes of the ejector rod 210 and the ball screw shaft 220 are arranged coaxially with the axis of the piston section 152, and the rotation axis of the ejector motor (not shown) is arranged at a different position from the axis of the piston section 152. has been done. Thereby, the total length of the mold clamping device 100 can be shortened. That is, the injection molding machine 10 can be made compact.

Furthermore, in the ejector device 200 of this embodiment, the ejector rod 210 is operated by an ejector motor (not shown). Therefore, by detecting the rotational speed of the ejector motor (not shown) with an ejector motor encoder (not shown), the position and operating speed of the ejector rod 210 can be measured. In other words, the control device 700 can easily control the position and speed of the ejector rod 210 by controlling the ejector motor (not shown).

Furthermore, a supply section 221 for supplying lubricant such as grease is provided at the tip of the ball screw shaft 220. The supply section 221 is formed of, for example, a nipple having a check valve. The ball screw shaft 220 also has a supply path 222 that communicates with the supply section 221 and extends in the axial direction from the tip of the ball screw shaft 220, and a supply path 223 that extends in the radial direction from the supply path 222.

Further, the piston portion 152 is formed with a discharge passage 159 that communicates the housing portion 158 with the outside. Furthermore, a pipe 159a is connected to the discharge path 159.

Here, when supplying lubricant to the motion conversion mechanism (ball screw shaft 220, ball screw nut 230), the ejector rod 210 is removed from the ball screw shaft 220, and the lubricant supply device (not shown) is supplied to the supply section 221. For example, connect a grease gun (for example, a grease gun) to supply lubricant. The lubricant supplied from the supply section 221 is supplied to the transfer surface between the ball screw shaft 220 and the ball screw nut 230 via supply paths 222 and 223. In addition, excess lubricant is discharged from the gap between the ball screw shaft 220 and the ball screw nut 230 to the housing section 158, and is further discharged to the outside through the discharge path 159 and the piping 159a from the housing section 158. .

Here, it is difficult to supply lubricant from the piston portion 152 and the ball screw nut 230 side to the transfer surface between the ball screw shaft 220 and the ball screw nut 230 because the ball screw nut 230 is configured to rotate. . Further, in the configuration in which the ball screw shaft 220 and the ball screw nut 230 are lubricated by supplying the lubricant to the housing portion 158 of the piston portion 152, the amount of lubricant used increases.

On the other hand, in the ejector device 200 of this embodiment, by supplying the lubricant from the ball screw shaft 220, it is possible to directly supply the lubricant to the transfer surface between the ball screw shaft 220 and the ball screw nut 230. This makes it possible to supply only the amount of lubricant needed, so the amount of lubricant can be reduced.

Note that the hole in the coupling portion 211 of the ejector rod 210 and the hole in the coupling portion 212 may be in communication with each other. According to such a configuration, the lubricant can be supplied from the supply section 221 without removing the ejector rod 210.

Further, although the supply section 221 has been described as being formed at the tip of the ball screw shaft 220, it is not limited to this. For example, the supply portion 221 may be formed on the cylindrical surface of the front side of the ball screw shaft 220. In this configuration, an ejector motor (not shown) is driven to move the ball screw shaft 220 forward, thereby causing the front side of the ball screw shaft 220 to protrude beyond the movable platen 120. Thereby, lubricant can be supplied to the supply portion 221 of the ball screw shaft 220 protruding from the hole portion 121 of the movable platen 120.

Alternatively, a working opening (not shown) may be provided in the pulley housing 270, and the lubricant may be supplied to the supply portion 221 formed on the cylindrical surface on the front side of the ball screw shaft 220. In this configuration, the ball screw shaft 220 and the ball screw nut 230 can be lubricated without removing the mold device 800 from the mold clamping device 100.

FIG. 8 is a partially enlarged sectional view showing another example of the ejector device 200 according to the present embodiment.

The pulley housing 270 is provided with a supply section 273 such as a nipple. Further, a flexible hose 274 is provided in the accommodation portion 271 of the pulley housing 270 to connect the supply portion 273 of the pulley housing 270 and the supply portion 228 formed on the front cylindrical surface of the ball screw shaft 220. There is. Thereby, lubricant is supplied from the supply section 273 of the pulley housing 270 to the supply section 228 of the ball screw shaft 220 via the hose 274. The lubricant supplied from the supply section 228 is supplied to the transfer surface between the ball screw shaft 220 and the ball screw nut 230 via the supply paths 222 and 223.

In addition, according to the ejector device 200 shown in FIG. 8, it is also possible to automatically supply lubricant by connecting the supply section 273 to an automatic supply device (not shown).

Further, a partition 226 may be provided to prevent the hose 274 from coming into contact with the ball screw nut 230 and the driven pulley 250, which are rotating bodies. The partition 226 may be sandwiched between the flange 225 of the ball screw shaft 220 and a lock nut 227 that threadably engages with the ball screw shaft 220, and may be fixed integrally with the ball screw shaft 220.

10 Injection molding machine 100 Mold clamping device 110 Fixed platen 120 Movable platen 121 Hole 140 Tie bar 150 Hydraulic cylinder (hydraulic cylinder)
151 Cylinder body section 152 Piston section 153 Rod section 154 Cylinder closing section 155 to 157 Oil chamber 158 Accommodation section 159 Discharge passage 160 Hydraulic circuit 161 Hydraulic pump 162 Hydraulic tank (tank)
163-165 Stop valve 166 Prefill valve 170 Servo motor 200 Ejector device 210 Ejector rod 211 Coupling section 212 Coupling section 220 Ball screw shaft 221 Supply section 222 Supply passage 223 Supply passage 224 Ejector crosshead 225 Flange section 226 Partition 227 Lock nut 228 Supply Part 230 Ball screw nut 240 Bearing 241 Spacer 242 Lock nut 250 Driven pulley 255 Bolt 260 Timing belt 270 Pulley housing 271 Accommodation part 272 Bolt 273 Supply part 274 Hose 300 Injection device 400 Moving device 700 Control device 701 CPU
702 Storage medium 703 Input interface 704 Output interface 750 Operating device 760 Display device

Claims (4)

a fixed platen to which a fixed mold is attached;
a movable platen to which a movable mold is attached;
a hydraulic cylinder that moves the movable platen forward and backward;
an ejector device that advances and retreats the ejector rod;
The piston portion of the hydraulic cylinder has a housing portion,
At least some components of the ejector device are arranged in the housing part ,
The ejector device includes a screw shaft and a screw nut that is threadedly engaged with the screw shaft,
The screw shaft moves forward and backward as the screw nut rotates, and has a supply path for supplying lubricant between the screw shaft and the screw nut,
The lubricant is supplied from the tip of the screw shaft through the supply path to a transfer surface between the screw shaft and the screw nut, and is supplied through a discharge path that communicates the housing section with the outside of the housing section. is discharged,
Injection molding machine. a fixed platen to which a fixed mold is attached;
a movable platen to which a movable mold is attached;
a hydraulic cylinder that moves the movable platen forward and backward;
an ejector device that advances and retreats an ejector rod;
comprising a housing ;
The piston portion of the hydraulic cylinder has a housing portion,
At least some components of the ejector device are arranged in the housing part ,
The ejector device includes a screw shaft and a screw nut that is threadedly engaged with the screw shaft,
The screw shaft moves forward and backward with respect to the housing as the screw nut rotates, and has a supply path for supplying lubricant between the screw shaft and the screw nut,
The housing has a supply part that supplies lubricant to the supply path,
a flexible hose connecting the supply section and the supply path of the screw shaft;
Injection molding machine. further comprising a pulley housed in the housing and fixed to the screw nut ;
The injection molding machine according to claim 2. having a partition separating the flexible hose and the pulley;
An injection molding machine according to claim 3 .

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