JP2013202800A - Injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection molding machine capable of recovering mechanical energy as electric energy even in an almost zero-speed vicinity.SOLUTION: A first power generation device (40a) and a second power generation device (40b) are installed respectively on a bed (7) in the vicinity of a position that a movable platen (12) of an injection molding machine is mold-closed and on the bed (7) in the vicinity of a position that it is mold-opened. Pressing rods (45, 45) are installed on both surfaces of the movable platen (12). When the movable platen (12) is mold-closed in order to obtain a molding, the pressing rods (45) of the movable plate (12) pressurize a piezoelectric element (43) of the first power generation device (40a) to generate power and when the movable platen (12) is mold-opened, the pressing rods (45) of the movable platen (12) pressurize the piezoelectric element (43) of the second power generation device (40b) to generate power. Thus, mechanical energy can be recovered as electric energy every time the molding is obtained even at a low open/close speed of the movable platen (12).

Description

  The present invention relates to an injection molding machine comprising a fixed-side member and a driven-side member that is driven in one direction when a molded product is obtained, and is temporarily stopped and driven in the other direction. Is provided with a power generation device in association with a driven member that is driven reciprocally when obtaining a molded product, and mechanical energy is recovered as electrical energy when obtaining the molded product. The present invention relates to an injection molding machine.

  The electric injection molding machine is well known in the art and generally includes an injection device and a mold clamping device. The injection device is composed of a heating cylinder, a screw or the like provided in the heating cylinder so as to be able to be driven in the rotational direction and the axial direction, and the screw is driven by an electric servomotor for plasticizing and injection. It has become. The mold clamping device includes a toggle mechanism that drives the movable plate to the fixed plate in the mold clamping direction or the mold opening direction, and this toggle mechanism is also driven by an electric servo motor or the like.

  Therefore, when the inside of the cylinder is heated by the heater provided on the outer periphery of the heating cylinder, the resin material is supplied from one end of the heating cylinder, and the screw is driven to rotate by the electric servomotor for plasticization, the resin The material is melted and weighed. Then, the toggle mechanism is driven by an electric servo motor for mold clamping, and the movable mold attached to the movable platen is driven in the forward direction toward the fixed die attached to the fixed platen. When the screw is driven in the axial direction by the electric servomotor for injection, the molten resin material at a predetermined temperature is injected and filled into the cavity of the mold that is clamped. When the movable mold is opened in a direction away from the fixed mold after waiting for cooling to a predetermined temperature, the retracted ejector pin projects and the molded product is ejected. This ejector pin is retracted when the movable mold is clamped. A molded product can be obtained by repeating the following cycle.

  By the way, as understood from the above description, in the injection molding machine, heat energy is consumed when the heating cylinder is heated or when the mold is cooled. Therefore, according to Patent Document 1, a thermoelectric generator is attached to the outside of the band heater wound around the outer peripheral portion of the heating cylinder, and between the heat transmitted to the generator when the heating cylinder is heated to a high temperature and the outside air temperature. There has been proposed a heat recovery method for generating electricity based on the temperature difference. Further, in an injection molding machine or a die casting machine, in order to keep the temperature of the mold constant, a cooling medium having a predetermined temperature is supplied and discharged into the mold. Patent Document 2 proposes an exhaust heat recovery method that generates power using a temperature difference with a medium.

JP 2009-326164 A JP 2010-36338 A JP 2001-154785 A

  On the other hand, a method using a piezoelectric element or a piezoelectric element is known as a method for obtaining electrical energy from mechanical energy. A keyboard power generator using this is disclosed in Patent Document 3. This power generation device is composed of a piezoelectric element disposed below a key of a notebook computer. Accordingly, pressure is applied to the piezoelectric element each time the key is pressed, and voltage, that is, electric power is obtained.

  As described above, in an injection molding machine or a molding machine, it can be said that heat energy is effectively converted and recovered into electric energy. However, as described above, in the injection molding machine, for example, the components of the mold clamping device are reciprocally driven every time a molded product is obtained, and once the direction is changed, the components are temporarily stopped, but the driving speed is reduced and stopped. The mechanical energy for this is wasted.

  The power generation device proposed by Patent Document 3 described above generates power with a mechanical pressing force. However, it is pressed by the force of a person's finger, and is not necessarily a recovery of mechanical energy. That is, electric energy obtained by human power. In general, a piezoelectric material, for example, a piezoelectric material in which an additive such as niobium, tantalum, lanthanum, or bismuth is added to the base material increases the output voltage as the load increases. Is heavy and not practical.

  Accordingly, an object of the present invention is to provide an injection molding machine provided with an energy recovery device that recovers mechanical energy as electrical energy, that is, a power generation device. Specifically, as is well known in the art, trains, automobiles, elevators, and the like have regenerative braking devices that convert kinetic energy into electrical energy and recover it, but kinetic energy is proportional to the square of speed, An object moving at a certain speed can be recovered by regenerative braking. However, when an object driven in a reciprocating manner changes direction, the speed needs to be once reduced to zero, but regenerative braking is not effective in the vicinity where the speed becomes zero. The present invention is intended to provide an injection molding machine that can recover mechanical energy as electric energy even in the vicinity of the speed becoming zero.

  In order to achieve the above object, the present invention provides a component of an injection molding machine that is driven reciprocally when obtaining a molded product, that is, a position near a position where a driven member decelerates and temporarily stops to change direction. In addition, a power generation device including a piezoelectric element and a pressurizing member that pressurizes the piezoelectric element is provided. This piezoelectric element is provided on the bed side, which is a fixed side member of the injection molding machine, and the pressure member is provided on a driven side member that is driven reciprocally. Or, conversely, the piezoelectric element is attached to the driven member, and the pressure member is attached to a stationary member such as a bed.

  That is, in order to achieve the above object, the invention according to claim 1 is driven in one direction when a molded product is obtained, and a driven side that is temporarily stopped and driven in the other direction. An injection molding machine comprising a member and a power generation device provided in association with the driven side member, wherein the power generation device is in the vicinity of a position where the driven side member stops temporarily. A piezoelectric element provided on the member and a pressurizing member provided on the driven side member and pressurizing the piezoelectric element in the vicinity of the position where the driven side member temporarily stops. According to a second aspect of the present invention, in the injection molding machine according to the first aspect, the pressurizing member is configured to be a part of the driven side member.

  The invention according to claim 3 relates to a fixed-side member, a driven-side member that is driven in one direction when a molded product is obtained, and is temporarily stopped and driven in the other direction, and the driven-side member. The power generation device includes a piezoelectric element provided on the driven side member and a position near the position where the driven side member stops, The pressure member is provided on the fixed side member and pressurizes the piezoelectric element in the vicinity of a position where the driven side member temporarily stops. According to a fourth aspect of the present invention, there is provided an injection molding machine according to any one of the first to third aspects, wherein the driven side member is a movable plate whose mold is opened and closed with respect to the fixed platen, and an ejector that projects a molded product. It is comprised so that it may be an ejector plate provided with a pin, a base to which an injection device is attached, or a member that drives a screw in the axial direction.

  As described above, according to the present invention, the power generation device includes the piezoelectric element provided on the fixed side member in the vicinity of the position where the driven side member temporarily stops and the driven side member. Since the driving member includes a pressurizing member that pressurizes the piezoelectric element in the vicinity of the position where the driving side member temporarily stops, the power generation device includes a piezoelectric element provided on the driven side member and the driven side member. Since it comprises a pressing member that is provided on the fixed side member in the vicinity of the stop position and pressurizes the piezoelectric element in the vicinity of the position where the driven side member temporarily stops, when obtaining a molded product, or Every time a molded product is obtained, mechanical energy is recovered as electric energy. At this time, according to the present invention, since the piezoelectric element or the pressurizing member that pressurizes the piezoelectric element is disposed in the vicinity of the position where the driven member stops, the kinetic energy or mechanical energy that cannot be recovered by regenerative braking is obtained. The effect that energy can be recovered is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the electric injection molding machine which concerns on embodiment of this invention, The (a) is a front view which shows the whole, The (a) is a front view which shows the attachment relation of a movable board and a piezoelectric element, ) Is a cross-sectional view showing a mounting relationship between a mold and a piezoelectric element.

  Hereinafter, an embodiment of the present invention will be described with reference to FIG. 1 by taking an electric injection molding machine equipped with a toggle type mold clamping device as an example. The electric injection molding machine according to the present embodiment includes an injection device 1 and a mold clamping device 10 disposed in front of the injection device 1. The injection device 1 includes a heating cylinder 2, a screw provided in the heating cylinder 2 so as to be driven in the rotational direction and the axial direction, an electric servomotor 4 for plasticizing that drives the screw in the rotational direction, and a screw as a shaft. The electric servomotor for injection 5 is driven in the direction, that is, the injection direction. As is well known, the plasticizing electric servo motor 4 and the injection electric servo motor 5 are coupled to the screw shaft via a gear mechanism, a ball screw mechanism, or the like.

  The injection apparatus 1 configured as described above is mounted on a base 6, and this base 6 is provided on a bed 7 so as to be movable in the axial direction. Therefore, the injection device 1 is movable with respect to the mold clamping device 10 in the direction in which the nozzle 3 abuts and in the direction in which the nozzle 3 abuts. For this purpose, an electric servomotor for movement is attached to the bed 7. The electric servomotor for movement, a screw mechanism for converting a rotary motion provided between the output shaft and the base 6 into a linear motion, etc. Is not shown in FIG.

  The outer shape or main body of the toggle type mold clamping device of the mold clamping device 10 is configured in the same manner as a conventional toggle type mold clamping device. That is, a fixed platen 11 fixed on the bed 7, a mold clamping housing 13 provided on the bed 7 so as to be axially movable at a distance from the fixed platen 11, the fixed platen 11 and the mold clamping housing 13. The four tie bars 14, 14,... Provided between the movable platen 12 are guided and moved in the axial direction by the four tie bars 14, 14,. And a mold clamping servomotor 30 for driving the toggle mechanism 20.

  One end of each of the tie bars 14, 14,... Is passed through the four corners of the fixed platen 11 and fixed to the fixed platen 11. The other ends of the tie bars 14, 14,... Penetrate through the four corners of the mold clamping housing 13 and extend to the outside. Further, on the outside of the mold clamping housing 13, screws are formed on the tie bars 14, 14,..., And mold thickness adjusting nuts 15, 15,.

  Since the toggle mechanism 20 is also well known in the art, it will not be described in detail. The toggle mechanism 20 includes a relatively long pair of first links, a relatively short pair of second links, a pair of third links, a crosshead 21, and the like. One end of the first link is pin-coupled to the movable platen 12, and the other end is similarly pin-coupled to one end of the second link. Similarly, the other end of the second link is pin-coupled to the mold clamping housing 13 and the end of the third link is pin-coupled to the second link and the crosshead 21, respectively.

  A ball screw 22 is provided in a through hole formed in a substantially central portion of the mold clamping housing 13, and the ball screw 22 is rotatably provided although movement in the axial direction is restricted. A ball nut 23 is fixed to the cross head 21 of the toggle mechanism 20, and the ball nut 23 is screwed into the ball screw 22. A large pulley 24 is fixed to the ball screw 22 protruding to the outside of the mold clamping housing 13, and the large pulley 24 is wound around by a small pulley 25 and a belt 26 provided in a mold clamping servomotor 30. . Accordingly, when the mold clamping servomotor 30 is driven in the forward direction or the reverse direction, the ball screw 22 is rotated and the cross head 21 is driven in the axial direction, and the movable platen 12 is reciprocally driven in the mold closing direction or mold opening direction. Will be.

  A fixed mold K1 is attached to the fixed platen 11 as is conventionally known, a movable mold K2 is attached to the movable platen 12, and an ejector device 32 is provided on the movable platen 12. Although not shown in detail in FIG. 1, the ejector device 32 is provided with an ejector plate, and this ejector plate is reciprocally driven by a servo motor, a ball screw mechanism or the like. When the ejector plate is driven, a plurality of ejector pins attached to the ejector plate penetrate through the movable mold K2 and project into the parting line, or retract from the parting line.

  As described above, according to the present embodiment, the base 6 on which the heating cylinder 2 is mounted and the movable platen 12 to which the movable mold K2 is attached are reciprocally driven relative to the bed 7. . The ejector plate to which the ejector pins are attached is reciprocally driven relative to the movable platen 12 or a member related to the movable platen. Thus, when the components of the injection molding machine are driven reciprocatingly, as described above, deceleration or braking is applied to temporarily stop and drive in the opposite direction. And the 1st, 2nd electric power generating apparatus 40a, 40b is provided in the vicinity of the position to stop.

  According to the present embodiment, the first and second power generators 40a and 40b include a protective box-shaped casing 41, a coil spring, a leaf spring, and rubber as shown in FIG. And the like, and a conventionally known piezoelectric element 43. The piezoelectric element 43 is attached to the bottom wall of the casing 41 via the elastic member 42. Therefore, the impact of the injection molding machine when the reciprocatingly driven component abuts against the piezoelectric element 43 is buffered, and once contacted, the voltage element is pressurized at a predetermined pressure without causing chattering. Will be. In the embodiment shown in FIG. 1A, the piezoelectric element 43 is pressurized by an operating bar 45 attached to the movable platen 12.

  According to the present embodiment, the movable platen 12, which is a component of the mold clamping device 10, is reciprocally driven to the mold clamping position and the mold open position every time a molded product is obtained. There are various members that are driven in such a manner as to reciprocate dynamically. For example, the ejector plate is reciprocally driven each time a molded product is obtained. Moreover, the injection device 1 is reciprocally driven to a position where the injection nozzle 3 touches the fixed mold K1 and a position where it is retracted as necessary. Further, although not shown in FIG. 1, the screw and the member for driving the screw in the axial direction are driven reciprocally in the metering operation and the injection operation. The components of the injection molding machine that are driven reciprocally in this way are decelerated and stopped when approaching the position to change direction, and are driven in the opposite direction. According to the present embodiment, the power generation devices 40a and 40b are provided in the vicinity of the position where the vehicle is decelerated and stopped. That is, as shown in FIG. 1A, when the movable platen 12 is driven in the mold clamping direction, the first power generator 40a is provided on the bed 7 near the mold clamping completion position. The second power generation device 40b is provided on the bed 7 in the vicinity of the mold opening end position. Similarly, the first power generation device 40a is provided in the bed 7 in the vicinity of the position touched by the injection nozzle 3, and the second power generation device 40b is provided in the vicinity of the end point position where the injection nozzle 3 is separated. The first and second power generators are similarly provided in relation to the ejector plate and further to the screw, but are not shown in FIG.

  Next, the operation of the above embodiment will be briefly described. As is conventionally known, the screw is rotated and measured. The mold clamping servomotor 30 is driven. Then, the movable platen 12 is clamped to the fixed platen 11 by the toggle mechanism 10. The injection nozzle 3 of the heating cylinder 2 is touched to the fixed platen 11. The injection electric servomotor 5 is activated to drive the screw in the injection direction. Thereby, the injection material is injected and filled into the cavities of the molds K1 and K2. After cooling and solidifying, the mold clamping servomotor 30 is driven to open the movable platen 12. Further, the servo motor of the ejector device 32 is driven. Then, the movable platen 12, and hence the movable mold K2, are opened, and the molded product is ejected by the ejector pins of the ejector device 32. Thereafter, the same cycle is repeated for molding.

  When molding as described above, when the movable platen 12 is driven in the mold clamping direction, the operating rod 45 attached to the movable platen 12 comes into contact with the piezoelectric element 43 of the first power generation device 40a. If the elastic member 42 is further driven while being compressed, the movable platen 12 will eventually stop. When stopped, the elastic member 42 is compressed by a predetermined amount, and the piezoelectric element 43 is pressurized with a predetermined pressure to generate a predetermined voltage. When the movable platen 12 is driven in the mold opening direction, an electromotive force in the reverse direction is obtained. Adjust the electromotive direction as appropriate.

  The movable platen 12 is driven in the mold opening direction. When reaching the vicinity of the position where the mold opening is completed, the operating rod 45 comes into contact with the piezoelectric element 43 of the second power generation device 40b. If mold opening is continued while the elastic member 42 is compressed, the movable platen 12 will eventually stop. When stopped, the elastic member 42 is compressed by a predetermined amount, and the piezoelectric element 43 is pressurized with a predetermined pressure to generate a predetermined voltage. Hereinafter, the voltage, that is, the electric power is obtained every time the molded product is obtained in the same manner. Electric power is obtained in the same manner by driving the ejector plate, by reciprocatingly driving the injection device 1, and further by driving the screw in the axial direction.

  In the above embodiment, the piezoelectric element 43 or the power generators 40a and 40b are attached to the outside of the bed 7. However, an embodiment in which the piezoelectric element 43 or the power generators 40a and 40b are embedded in the fixed mold K1 is shown in FIG. It is shown. Constituent elements similar to those in the above embodiment are given the same reference numerals and will not be described repeatedly. However, according to this embodiment, a part of the parting surface P of the movable mold K2 is an actuating rod or a pressurizing part. It has become. Although the piezoelectric element 43 protrudes from the parting surface P by the elastic member 42 in the mold open state, the elastic member 42 can be compressed and clamped. When the mold is clamped, the piezoelectric element 43 is pressurized with a predetermined pressure. Although not shown in FIG. 1, it is clear that electric power can be obtained reciprocally by providing a similar piezoelectric element on the mold opening side of the movable mold K2.

  According to the present embodiment, since the power generation device includes the piezoelectric element and the pressing member or the operating rod, the piezoelectric element and the pressing member are relative. Therefore, the piezoelectric element can be provided on the component that is driven reciprocally and the pressing member or the operating rod can be provided on the fixed member such as the bed 7.

DESCRIPTION OF SYMBOLS 1 Injection device 3 Injection nozzle 6 Base 7 Bed 10 Clamping device 11 Fixed platen 12 Movable platen 40a First power generation device 40b Second power generation device K1 Fixed mold K2 Movable die

Claims (4)

A fixed-side member, a driven-side member that is driven in one direction when obtaining a molded product, and is temporarily stopped and driven in the other direction; and a power generation device provided in association with the driven-side member An injection molding machine comprising:
The power generation device includes a piezoelectric element provided on the fixed-side member in the vicinity of a position where the driven-side member temporarily stops and the driven-side member, and the driven-side member temporarily stops. An injection molding machine comprising a pressurizing member that pressurizes the piezoelectric element in the vicinity of the position. 2. The injection molding machine according to claim 1, wherein the pressure member is a part of the driven side member. A fixed-side member, a driven-side member that is driven in one direction when obtaining a molded product, and is temporarily stopped and driven in the other direction; and a power generation device provided in association with the driven-side member An injection molding machine comprising:
The power generation device is provided on the fixed side member in the vicinity of a position where the driven side member stops and the piezoelectric element provided on the driven side member, and the position where the driven side member stops temporarily An injection molding machine comprising a pressurizing member that pressurizes the piezoelectric element in the vicinity. The injection molding machine according to any one of claims 1 to 3, wherein the driven side member is a movable plate whose mold is opened and closed with respect to the fixed platen, an ejector plate provided with an ejector pin for projecting a molded product, An injection molding machine that is a base on which an injection device is attached or a member that drives a screw in the axial direction.

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