JP2005306028A - Scroll for injection molding apparatus and injection molding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small size and light weight injection molding apparatus as a whole. <P>SOLUTION: An injection molding apparatus comprises a plasticating block 11 having a plasticating/force-feeding mechanism installed therein for heating-and-plasticating, mixing and force-feeding a material, a metering block 31 provided with a metering-delivering mechanism therein for metering and delivering the material force-fed by the plasticating/force-feeding mechanism, a fixed die plate 211 equipped with an injection mechanism for injecting the metered/delivered material into a cavity, a movable die plate 213 to be brought into contact with the fixed die plate 211 for closing the cavity to form a closed space, and a mold-clamping housing 212 having a movable die plate driving mechanism provided therein and installed apart from the fixed die plate 211 by a plurality of tie bars 40 on which the movable die plate 213 is loosely fitted for allowing the movable die plate 213 to be moved back and forth against the fixed die plate 211 for generating a specified clamping force upon contact. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a small motor-driven injection molding apparatus that does not require a frame.

  The injection molding apparatus includes a mold clamping device for clamping the mold so that the cavity in the mold becomes a closed space, an injection unit for injecting plasticized material into the cavity, and a plasticizing unit for plasticizing the material. Basic configuration.

  However, since such a conventional injection molding apparatus is large and heavy, a reduction in size and weight is desired, and various techniques have been proposed. For example, by using a telescoping exchangeable cassette around the cavity, a technology for reducing the size and weight of the cassette mold (see Patent Document 1), and a screw and motor for plasticizing the material with a gear meshing structure. A technique (see Patent Document 2) for reducing the size and weight by assembling substantially integrally has been proposed.

In addition, a technique for reducing the size and weight has been proposed in which a mold clamping mechanism is provided on the injection device side, a long screw is replaced with a short conical screw, or pneumatically driven (see Patent Documents 3 and 4).
No. 7-36729 JP-A-11-207744 Japanese Patent Publication No. 8-1740 Japanese Patent Publication No. 7-164494

  However, in such a miniaturization and weight reduction technology, a proposal for miniaturization and lightening for each component, and as a result, miniaturization and weight reduction of the entire injection molding apparatus is achieved, so that sufficient miniaturization and weight reduction cannot be achieved. was there.

  That is, the above proposals are the basis for reducing the weight of the injection molding apparatus by independently reducing the basic structure of the mold, mold clamping device, injection unit, plasticizing unit, etc. The basic configuration including the layout and the like of each element must be inherited, and for example, the longitudinal dimension of the injection molding apparatus remains almost unchanged.

  In addition, since each element is reduced in size and weight independently, it is not possible to effectively reduce the size and weight in cooperation with each other, so that a so-called dead space is likely to occur, and originally it is handled by a plurality of elements. There is a problem that even a load that can be produced is not designed to be reduced in size and weight sufficiently because it tends to be designed to be handled by each element.

  Therefore, the present invention has been made in consideration of such problems, and by comprehensively examining the injection molding apparatus as a whole, it is possible to achieve ease of assembly without degrading the performance of the injection molding apparatus. An object of the present invention is to provide an injection molding apparatus and a scroll for an injection molding apparatus that achieves miniaturization, weight reduction, and simplification by suppressing the occurrence of dead space and reducing the number of parts while satisfying the requirements.

  In order to solve the above problems, the invention according to claim 1 is an injection molding apparatus for injecting a plasticized material into a cavity of a mold to inject a product, and heating the material to plasticize the product. , A plasticizing block having a plasticizing pumping mechanism for pumping while kneading, and a plastic block connected closely to the plasticizing block, and the material pumped by the plasticizing pumping mechanism is measured and sent inside A metering block provided with a metering delivery mechanism, a fixed die plate provided with an injection mechanism for injecting the material metered and delivered by the metering delivery mechanism into the cavity, and moving forward and backward toward the fixed die plate, When abutting against the fixed die plate, the fixed die plate and the fixed die plate are placed by a movable die plate that makes the cavity substantially closed and a plurality of tie bars that guide the movable die plate. A movable die plate that is fixedly spaced apart and that moves the movable die plate forward and backward with respect to the fixed die plate and generates a predetermined clamping force when the movable die plate contacts the fixed die plate. And a clamping housing in which a driving mechanism is provided.

  Further, in the invention according to claim 2, the plasticizing and feeding mechanism has a barrel for heating and plasticizing the material, a spiral groove for conveying the material, and rotating while in contact with the barrel. It is characterized by having a scroll of a substantially short cylindrical rotating body that promotes plasticization and kneading of the material and pumps it to an injection cylinder formed at the center of rotation, and a scroll driving unit that rotates the scroll.

  The invention according to claim 3 is characterized in that the spiral groove in the scroll is formed by cutting the end mill parallel to the rotation axis of the scroll so as to contact the side surface of the rotary body, , Formed continuously by spiral cutting so that the front surface of the rotating body is reduced toward the center of rotation continuously with the scraping groove, and is responsible for transporting, plasticizing, kneading and pumping the scraped material It consists of a feeding groove.

  The invention according to claim 4 is characterized in that the respective contact surfaces of the scroll and the barrel are formed in a conical shape.

  The invention according to claim 5 is characterized in that the respective contact surfaces of the scroll and the barrel are formed in a concave conical shape recessed toward the scroll side.

  According to a sixth aspect of the present invention, the scroll driving unit is engaged with the worm gear that obtains rotational power by the motor, the worm gear meshes with the worm gear to reduce the rotational speed of the motor, and the scroll driving unit is detachable from the scroll through the heat insulating plate. And a worm wheel that rotates the scroll at a reduced rotational speed.

  In the invention according to claim 7, the metering delivery mechanism drives the injection plunger inserted through the injection cylinder, the plunger ball screw detachably engaged with the injection plunger by the dovetail groove, and the plunger ball screw. And a plunger driving unit that applies a feed force of the material that has been pressure-fed to the injection plunger by moving the injection plunger in the injection cylinder.

  Further, in the invention according to claim 8, the plunger driving portion is engaged with the worm gear that obtains rotational power by the motor, and the rotational speed of the motor is reduced and transmitted to the plunger ball screw by meshing with the worm gear. And a worm wheel for piston-moving an injection plunger removably engaged with the ball screw.

  In the invention according to claim 9, the injection plunger is formed by piercing from the tip surface thereof, and formed by grooving the side surface in the longitudinal direction, and the groove end on the tip side is the tip hole. An introduction hole formed so as to communicate, a notch for cutting out the tip hole in the longitudinal direction, a delivery notch for sending material from the tip hole, and a free engagement with the tip hole while engaging with the tip hole. When the pressure on the delivery notch side becomes higher than the pressure on the introduction hole side, the communication between the delivery notch and the introduction hole is cut off to stop the material injection, and the pressure on the delivery notch side is reduced to the introduction hole side. And a valve body that allows the material to be injected by communicating the delivery notch and the introduction hole when the pressure becomes lower than the pressure.

  In the invention according to claim 10, the injection mechanism is selected by attaching the hot runner into which the material delivered by the injection plunger flows and the hot runner selected according to the product to be injection-molded. And a hot runner hole that detachably accommodates the hot runner and the nozzle.

  According to an eleventh aspect of the present invention, the movable die plate drive mechanism meshes with a mold clamping ball screw that is screwed with a ball screw nut attached to the movable die plate, a worm gear that obtains rotational power by a motor, and the worm gear. And a worm wheel that moves the movable die plate forward and backward by decelerating the number of rotations of the motor and transmitting it to the mold clamping ball screw.

  According to a twelfth aspect of the present invention, the mold for forming the cavity is fixed to the fixed die plate attached to the fixed die plate, and the movable die plate is in contact with the fixed die plate. A movable mold piece that forms a cavity in a substantially closed space, a taper pin formed on one of the movable mold piece or the fixed mold piece, and a movable mold piece formed on the other mold piece. When the mold piece comes into contact with the fixed mold piece, the taper pin has a taper hole through which a taper pin is inserted and aligned.

  Further, the invention according to claim 13 is directed to an extruding portion to which a plurality of extruding pins provided so as to pass through the movable die piece and to be inserted into the cavity, and the head of the extruding pin is usually a wall surface of the cavity. Formed on the movable die plate, and when the movable die plate retracts to the mold clamping housing side by a predetermined amount or more, the head of the ball screw for clamping is inserted through the pusher. And an insertion hole that allows the injection-molded product in the cavity to be pushed out by pushing the pushing portion against the spring against the spring.

  The invention according to claim 14 is provided with a plurality of plasticizing units each comprising one plasticizing block and a metering block, and a mold clamping unit comprising a fixed die plate, a movable die plate and a mold clamping housing. And a mold clamping unit moving section that moves the mold clamping unit corresponding to each plasticizing unit so that different materials can be injected into one cavity.

  Further, the invention according to claim 15 is a scroll for an injection molding apparatus that feeds the plasticized material by scraping and conveying the material, and at this time, promoting plasticization and kneading of the material. However, it is formed by cutting the end mill parallel to the rotation axis and cutting the end mill to the side of the rotating body, and the front surface of the rotating body is rotated continuously with the scoring groove for scraping the material. It is characterized by having a spiral groove formed by cutting in a spiral shape so as to shrink toward the center and comprising a feed groove for carrying, plasticizing, kneading, and pumping of the scraped material.

  The invention according to claim 16 is characterized in that the surface formed by connecting the groove top portions of the feed groove in the scroll has a conical shape.

  The invention according to claim 17 is characterized in that the surface formed by connecting the groove tops of the feed grooves in the scroll has a concave conical shape that is recessed toward the center thereof.

  According to the present invention, a material is heated and plasticized, and a plasticizing block in which a plasticizing pumping mechanism for pumping the material while kneading is provided is closely connected to the plasticizing block, and the plasticizing block is plasticized therein. A fixed die provided with a metering block provided with a metering delivery mechanism for metering and sending out the material pumped by the pressure feeding mechanism, and an injection mechanism for injecting the material metered out by the metering delivery mechanism into the cavity Fixed by a plate, a movable die plate that advances and retreats toward the fixed die plate and makes the cavity substantially closed when abutting against the fixed die plate, and a plurality of tie bars that guide the movable die plate The movable die plate is fixed at a predetermined distance from the die plate, and the movable die plate is moved forward and backward with respect to the fixed die plate. Equipped with a mold-clamping housing with a movable die-plate drive mechanism that generates a predetermined mold-clamping force when it comes into contact with the die plate, making it easy to assemble without degrading the performance of the injection molding device While satisfying the characteristics, the generation of dead space can be suppressed and the number of parts can be reduced, so that reduction in size and weight and simplification can be achieved.

  Further, the scroll is formed by cutting the end mill parallel to the rotation axis and cutting the end mill to the side surface of the rotating body, and a scoring groove for scrambling the material, It has a spiral groove that is formed by cutting the front surface in a spiral shape so that it shrinks toward the center of rotation, and it consists of a feed groove that carries transported, plasticized, kneaded, and pressure-fed materials. Efficient conveyance, plasticization, kneading, and pressure feeding are possible.

  Embodiments of the present invention will be described with reference to the drawings. 1 is a perspective view, and FIG. 2 is a cross-sectional view. In this embodiment, a case where a thermoplastic resin is injection molded will be described as an example. However, it can be similarly applied to a case where a thermosetting resin, wax, binder-treated ceramic / iron powder is injection molded. To do.

  The injection molding apparatus heats and plasticizes a material, and also includes a plasticizing block (body) 11 having a plasticizing pumping mechanism (body) 11 in which a material is pumped while being kneaded, and is in close contact with the plasticizing block 11. And a metering injection unit 3 including a metering block (body) 31 provided with a metering mechanism for metering and feeding the material pumped by the plasticizing pumping mechanism.

  Further, the present injection molding apparatus includes a fixed die plate (fixed side member) 211 that also serves as a mold die provided with an injection mechanism for injecting the material measured and delivered by the measurement delivery mechanism into the cavity, and the fixed die. A movable die plate (movable side member) 213 that also serves as a mold base for making the cavity substantially closed when the advancing and retreating toward the plate 211 comes into contact with the fixed die plate 211, and a movable die plate The fixed die plate 211 is fixedly spaced apart from the fixed die plate 211 by a plurality of tie bars 40 guided by loosely fitting 213, and the movable die plate 213 is moved forward and backward with respect to the fixed die plate 211. A mold clamping housing in which a movable die plate driving mechanism for generating a predetermined mold clamping force when abutting against the fixed die plate 211 is provided. And a mold member 2 comprises a fixed-side member) 212.

Details will be described below.
On one side surface of the plasticizing block 11 (the surface that becomes the upper side during installation), a material charging hole 13 into which a material such as pellets is charged is formed.

  In addition, a plasticizing pumping mechanism (kneading mechanism) is provided inside the plasticizing block 11, and this plasticizing pumping mechanism includes a barrel 121 for heating the material charged from the material charging hole 13, and a spiral groove for transporting the material. 43 is formed, and the material is heated while being in contact with the barrel 121 to be conveyed, stirred, plasticized, kneaded, and after plasticization, a scroll shaft hole formed at the center of rotation with the Weisenberg effect. A scroll 12 that is pressure-fed to 44 and a scroll driving unit 42 that rotationally drives the scroll 12 are provided.

  The scroll 12 is a rotating body having a substantially short cylindrical shape as shown in FIG. 3 and the like, and a spiral groove 43 is formed from the side surface of the rotating body to the surface on the fixed die plate 211 side. The spiral groove 43 is formed so as to be reduced in accordance with the rotation direction of the scroll 12 to the vicinity of the scroll shaft hole 44 through which the injection plunger 32 formed on the rotation shaft is inserted. A joint groove 49 is formed. The scroll shaft hole 44 also serves as the injection cylinder 41.

  Hereinafter, the surface on the fixed die plate 211 side is referred to as a scroll working surface 47 and the side surface thereof is referred to as a scroll side surface 48. The spiral groove 43 formed on the scroll working surface 47 is referred to as a feeding groove (kneading groove) 45, and the spiral groove 43 formed on the scroll side surface 48 is referred to as a scraping groove (guide groove) 46. Accordingly, the spiral groove 43 is constituted by the scraping groove 46 and the feeding groove 45.

  3A is a perspective view of the scroll working surface 47, FIG. 3B is a cross-sectional view taken along the line AA in FIG. 3A, and FIG. is there.

  The scroll working surface 47 and the barrel 121 are in close contact so that the material plasticized by the heat from the barrel 121 does not leak from the feed groove 45, and the material passes along the feed groove 45 in the scroll shaft hole 44. It is supposed to be pumped towards.

  At this time, if the direct pressure (N) causing the material to generate a frictional force (F = Nμ) on the contact surface with the barrel 121 is small, the material slips (idle feed state) and cannot be pumped. In particular, in the case of a slippery material such as nylon, PBT, and an oil-containing polymer, there are many cases in which pumping cannot be performed.

  Therefore, in the present invention, as shown in FIG. 3B, the vertical angle θ of the scroll working surface 47 is formed to have a concave conical shape close to a plane of θ = 176 degrees to 174 degrees, and the direct pressure (N ) Can be used to pump the material.

  In addition, the fact that the scroll action surface 47 is formed in a concave conical shape means that the groove depth becomes shallower as the feed groove 45 approaches the scroll shaft hole 44. Therefore, the direct pressure (N) increases as the feed groove 45 approaches the scroll shaft hole 44, and reliable pumping is possible.

  Further, the Weissenberg effect and changes in peripheral speed are added, so that a large pumping force can be obtained while being small and thin, and an excellent plasticizing and kneading action can be obtained.

  FIG. 3B shows the case where the scroll action surface 47 is formed in a concave conical shape, but it may be formed in a convex conical shape.

  The material of the scroll 12 is not limited to an iron-based metal, and may be formed of, for example, a high-heat-resistant polymer resin such as brass, polytetrafluoroethylene, or polypyromellitimide.

  Such a spiral groove 43 is formed by cutting an end mill having an arcuate tip toward a direction perpendicular to the scroll action surface 47 (parallel to the rotation axis of the scroll 12).

That is, the cutting groove 46 is formed by cutting the side surface of the end mill against the scroll side surface 48, and in this state, the feed amount of the end mill is gradually decreased (the end mill is moved away from the scroll 12). Then, cutting is performed along the peripheral surface of the scroll side surface 48, and when the end of the end mill reaches the scroll action surface 47, the feed amount of the end mill is fixed and the scroll shaft hole 44 is spirally cut.
Thereafter, the scroll action surface 47 is cut so as to have a conical shape.

  Accordingly, the spiral groove 43 can be formed with a single stroke without changing the direction of the rotation axis of the end mill, which facilitates the cutting process and reduces the manufacturing cost.

  In the present invention, the scroll 12 is not limited to a one-piece cut product, but may be manufactured by pouring resin or metal into a mold.

  The scroll drive unit 42 includes a worm wheel 14 whose boss is detachably engaged with the drive unit engaging groove 49 via a heat insulating material, a worm gear 15 meshing with the worm wheel 14, a motor 4 for rotating the worm gear 15, a worm The worm wheel 14 and the worm gear 15 have a reduction mechanism including the wheel 14 and the thrust bearing 50.

  When the motor 4 rotates, the rotation speed is transmitted to the scroll 12 while being decelerated by the worm wheel 14 and the worm gear 15, and the scroll 12 rotates.

As shown in FIG. 4, the barrel 121 has a substantially disc shape with an injection cylinder 41 formed at the center, and heater holes 84 are radially formed in a tangential direction in contact with a circle near the injection cylinder 41. Reference numeral 84 denotes a cartridge heater internal heating system in which a rod-shaped electric heater (not shown) is accommodated. Further, a temperature measuring instrument such as a thermocouple (not shown) can be attached.
4A is a diagram showing the surface with which the scroll working surface 47 abuts as a top view, FIG. 4B is a cross-sectional view taken along line BB in FIG. 4A, and FIG. Is shown. In FIG. 4C, the heater hole 84 is indicated by an imaginary line.

  As described above, the surface 30 of the barrel 121 is formed in a conical shape convex toward the scroll 12 so as to be in contact with the scroll operation surface 47, and the surface 30 and the scroll operation surface 47 come into contact with each other, so The groove space is closed.

An injection cylinder 41 communicating with the scroll shaft hole 44 is formed at the center of the barrel 121, and an injection plunger 32, which will be described later, is inserted into the injection cylinder 41 so as to perform a piston motion.
In order to make it possible to use the injection plunger 32 having various outer diameters depending on the product to be injection-molded, a sleeve-like injection cylinder 39 as shown in FIG. 5 can be inserted according to the outer diameter. Yes.

5A is a cross-sectional view of the injection cylinder 39, FIG. 5B is a cross-sectional view when the injection cylinder 39 is mounted on the injection cylinder 41, and FIG. It is sectional drawing which shows the state in the middle.
Such a barrel 121 is accommodated and fixed in the barrel pocket 52 formed in the fixed die plate 211 and the plasticizing block 11.

  As described above, by using the internal heating system of the cartridge heater in which a plurality of heater holes 84 are formed and the heater holes 84 are radially formed in contact with the circle in the vicinity of the injection cylinder 41, the heat capacity and volume of the heater can be reduced. The capacity can be reduced, and a temperature gradient is realized between the outer peripheral portion and the central portion.

  The reduction in the heat capacity of the heater means that the temperature controller including the power supply can be miniaturized in combination with the internal heating method, and an effect of suppressing excessive heat supply without using a large-capacity heater is brought about.

  Further, by providing a temperature distribution such that the temperature at the center of the barrel 121 is the melting temperature and the temperature at the outer periphery is equal to or lower than the material melting point, the temperature of the material increases from the material charging hole 13 side toward the injection cylinder 41. Therefore, it is possible to prevent the inconvenience of welding the material immediately after charging and forming a dumpling, and since the material is gradually softened and compressed from the granular state, the air is naturally discharged and the entrainment of air in the plasticized material can be prevented. It becomes like this.

  A cartridge heater is used to create such a temperature distribution that the temperature at the outer peripheral portion is low and the temperature increases toward the central portion, and the tangential direction in contact with the circle near the injection cylinder 41 as shown in FIG. It is set as the structure arranged in.

Since the conventional screw is formed in the shape of a cylindrical rod or a conical rod as described above, the heat capacity of the screw and the barrel 121 is increased, a large amount of heat is required and the time until standby is increased, and the heat radiation amount is increased. There were many configurations.
Furthermore, since the conventional screw is externally heated and the amount of heat released to the atmosphere is such that the scroll 12 according to the present invention uses an internal heating method, such a heat loss is very small, and the heating time can be shortened. is there.

  As shown in FIG. 2, the plasticizing block 11 contains a heat insulating material 54, and a cooling water passage 55 is formed in which the cooling water flows adjacent to or in contact with the heat insulating material 54. The heat insulating material 54 and the cooling water channel 55 are formed in an annular shape so as to surround the periphery of the barrel 121, and have an action of suppressing diffusion of heat from the barrel 121 to the plasticizing block 11.

  On the other hand, the barrel pocket 52 in the fixed die plate 211 is formed to be appropriately larger than the barrel 121, and is formed so that the back surface (the mold part 2 side) of the barrel 121 forms a cavity. In addition, a cooling water channel 53 through which cooling water flows is formed in the fixed die plate 211.

  The cavity in the barrel pocket 52 serves to insulate the heat of the barrel 121 from being transmitted to the mold part 2 and the hot runner 57 described later via the fixed die plate 211, and the cooling water channel 53 is a cavity. This is to compensate for the lack of the heat insulation effect due to the flow of cooling water.

An injection plunger 32 is inserted into the injection cylinders 39 and 41, and a hot runner 57 is provided on the tip of the injection cylinder 39 and 41 so as to protrude toward the mold part 2 side. The hot runner 57 includes a hollow runner tube 58 and a nozzle 59 that is screwed into the tip of the runner tube 58. As the nozzle 59, for example, as shown in FIG. 6, nozzles 59 (59a to 59c) having different tip shapes are prepared, and are selected and used in accordance with the size or the like of the product to be injection-molded.
Therefore, only by replacing the nozzle 59, various products can be injection-molded, and there is an advantage that versatility is enhanced.

The metering block 31 in the metering injection unit 3 is provided with a metering and feeding mechanism for metering material and feeding it to the mold unit 2 via the hot runner 57.
As shown in FIGS. 2, 7 to 10, and the like, the metering delivery mechanism includes an injection plunger 32 that is inserted through the scroll shaft hole 44 of the scroll 12, and a plunger ball screw 33 that is detachably engaged with the injection plunger 32. The plunger ball screw 33 is driven to cause the injection plunger 32 to move as a piston to measure and send out the material pressure-fed to the injection plunger 32.

  7 is a view of the metering block 31 as viewed from the injection plunger 32 side. FIG. 8A is a cross-sectional view showing the main part of the metering delivery mechanism, and FIG. 8B is a perspective view of the injection plunger 32.

  The injection plunger 32 has a rod-like body in appearance, and is formed by digging a tip hole 69 drilled from the tip to the inside and a side surface in the longitudinal direction, and a groove end on the tip side communicates with the tip hole 69. The inlet hole 65 and the tip hole 69 are formed so as to be cut out along the tip hole 69, and are engaged with the tip hole 69 while being loosely fitted in the delivery notch 64 and the tip hole 69 for injecting the material of the tip hole 69. It has a valve body 66 that functions as a check valve that stops and prevents the material from flowing back. The valve body 66 is not limited to a spherical body, and may be a truncated cone shape.

  FIG. 9 is a diagram showing a detailed configuration of the injection plunger 32 when a spherical ball is used as the valve body 66, and FIG. 10 is a diagram showing a detailed configuration when the truncated cone shaped valve body 66 is used. The arrows in FIGS. 9 and 10 indicate the flow of the material. FIGS. 9B and 10B illustrate the case where the valve body 66 moves up, and FIGS. 9C and 10C illustrate the valve. The case where the body 66 moves down is shown.

  The injection plunger 32 is inserted into the scroll shaft hole 44 and the injection cylinder 41 forming the injection cylinder, and when the pressure on the delivery notch 64 side becomes higher than the pressure on the introduction hole 65 side, the valve body 66 moves upward and is used for delivery. The communication between the notch 64 and the introduction hole 65 is blocked. This stops the material injection.

  On the other hand, when the pressure on the delivery notch 64 side becomes lower than the pressure on the introduction hole 65 side, the valve body 66 moves down and the delivery notch 64 and the introduction hole 65 communicate with each other. Thereby, the material is injected.

In the conventional injection molding equipment, a check valve is provided to prevent such backflow of material. However, the check valve of the conventional configuration has a check ring attached to the end of the plunger with a screw attached to the blade. In order to prevent the valve body from falling off, it has been pointed out that this Yaba screw has a problem of fatigue failure in several months.
However, since the check valve according to the present invention does not require a screw structure, the check valve does not break down due to fatigue and has such a feature that such inconvenience does not occur.

  The introduction holes 65 and the like form a torpedo that lowers the viscosity of the plasticized molten material and stabilizes the viscosity. In the present invention, since the important elements indispensable for such plasticization are provided without providing a special space, the size can be reduced.

  The plunger drive unit 61 includes the motor 6, a worm gear 37 that obtains rotational power by the motor 6, and meshes with the worm gear 37 to reduce the rotational speed of the motor 6 and transmit it to the plunger ball screw 33. A worm wheel 36 that piston-moves the injection plunger 32 that is detachably engaged with 33 is provided.

  The plunger ball screw 33 has a ball screw structure, and the ball screw nut 35 is fixed to the measuring block 31. Therefore, when the plunger ball screw 33 rotates, the plunger ball screw 33 advances and retreats according to the rotation direction.

  The injection plunger 32 is connected to a plunger ball screw 33, and receives a driving force from the plunger driving unit 61 via the plunger ball screw 33 to cause a piston movement in the injection cylinder. At this time, the structure in which the injection plunger 32 and the plunger ball screw 33 are engaged by the dovetail groove 34 as shown in FIG. .

  The rotational power of the plunger ball screw 33 is transmitted from the motor 6 to the plunger ball screw 33 via the worm gear 37 and the worm wheel 36. At this time, the worm wheel 36 is moved in the axial direction of the plunger ball screw 33. Since a load is applied, a thrust bearing 68 that receives the load is provided with the worm wheel 36 interposed therebetween.

  By the way, in a configuration in which a ball screw and a large-capacity motor are directly connected as in the past, or in a configuration in which the injection plunger 32 is driven by hydraulic pressure or pneumatic pressure, when holding pressure (injection molding) and during plasticization measurement, In the control of the injection plunger 32, the injection plunger 32 can freely retreat and release pressure according to the set pressure holding value.

  However, if the plunger drive unit 61 is composed of the worm gear 37 and the worm wheel 36 in order to save space and reduce power consumption during holding pressure as in the present invention, it is difficult to release the pressure and the valve body 66 moves. In some cases, the material may not be delivered to the runner tube 58.

  Therefore, in the present invention, as shown in FIG. 2, the nut urging spring 100 that abuts on the ball screw nut 35 and urges toward the injection plunger 32, the abutment with the nut urging spring 100, and the injection plunger 32. A load cell 101 for controlling the load applied to the measuring block 31 is provided.

  The load spring 101 is controlled by the nut biasing spring 100 so that the ball screw nut 35 can slide within a stroke of, for example, 1 mm or less, and the pressure is released when the valve element 66 contacts the runner tube 58. The material can be injected.

  The mold is a cassette mold 22 including a movable mold piece (movable side member) 222 attached to the movable die plate 213 and a fixed mold piece (fixed side member) 221 attached to the fixed die plate 211.

  FIG. 11 is a view showing the configuration of such a cassette mold 22, and FIG. 11 (a) is a front view of the fixed mold piece 221 viewed from the injection plunger 32 side, and FIGS. 11 (b) and 11 (c). FIG. 12 is a cross-sectional view of the fixed mold piece 221 and the movable mold piece 222 in FIG.

One of the mold pieces 221 (222) is provided with a plurality of positioning pins 74, and a pin receiving hole 75 in which the positioning pins 74 are fitted to the opposing mold piece 222 (221). .
Furthermore, a runner receiving hole 76 into which the hot runner 57 is inserted is formed in the fixed mold piece 221 attached to the fixed die plate 211.

  The movable mold piece 222 is provided with a molded product pushing mechanism. The molded product push-out mechanism has a support plate 93 to which a plurality of extrusion pins 92 provided so as to pass through the cavity through the movable mold piece 222 are fixed, and is fixed to the support plate 93 and the movable mold piece. A support rod 95 to be inserted into 222, a spring 97 which is inserted into the support rod 95 and normally biases the support plate 93 so that the head 99 of the push pin 92 forms the wall surface of the cavity, and is fixed to the support plate 93. And a thrust bearing 98 attached to the extrusion plate 94 and an insertion hole 106 formed in the movable die plate 213. The support plate 93, the push plate 94, and the support bar 95 constitute the push portion 91.

  When the movable die plate 213 is retracted by a predetermined amount or more toward the mold clamping housing 212 when taking out the injection-molded product, the molded product push-out mechanism moves the head 105 of the mold clamping ball screw 23 (see FIG. 2). ) Is inserted through the insertion hole 106 and comes into contact with the thrust bearing 98 to push the support plate 93 against the spring 97 toward the cavity. Thereby, the injection molded product in the cavity is extruded by the extrusion pin 92.

  The thrust bearing 98 is provided to prevent the head 105 of the clamping ball screw 23 from damaging the extrusion plate 94, and may be a thrust sliding bearing or the like.

  As a result, the product can be taken out automatically without providing a product push-out mechanism, and the space can be saved and the convenience is improved.

  Although the total length of the injection molding apparatus is slightly longer, an apparatus in which the elements of the air cylinder / piston or the mold opening / closing drive mechanism are reduced to about 1/5 may be mounted on the movable die plate.

  As described above, the cassette mold 22 is a single-open type composed of the fixed mold piece 221 and the movable mold piece 222. The fixed mold piece 221 is clamped to the fixed die plate 211 by the clamper 78, and the movable mold piece 222 is clamped to the movable die plate 213 by a clamper 78.

  The clamper 78 opens a clamp claw 80 that engages a clamp groove 79 provided in the fixed mold piece 221 and the movable mold piece 222, a clamp bolt 81 that pushes the clamp claw 80, and a clamp claw 80, respectively. A spring (not shown) for biasing is provided.

  The clamp bolt 81 has a hemispherical tip, or a valve body 66 attached to the tip, and a hexagon wrench groove formed at the rear end, and is screwed into the fixed die plate 211 and the movable die plate 213.

  The clamp pawl 80 is swingably attached to the fixed die plate 211 and the movable die plate 213. When the clamp bolt 81 is tightened, the clamp pawl 80 comes into contact with the clamp groove 79, and the fixed mold piece 221 and the movable mold are fixed. The pieces 222 are pressed and clamped to the fixed die plate 211 and the movable die plate 213 side, respectively.

  On the other hand, when the clamp bolt 81 is loosened, the spring is biased so that the clamp pawl 80 is separated from the fixed mold piece 221 and the movable mold piece 222, and the clamp is released.

  As shown in FIG. 11, a plurality of positioning pins 74 are provided on one of the fixed mold piece 221 and the movable mold piece 222, and a plurality of positioning pins 74 are fitted on the other. Pin receiving holes 75 are formed, and these form a positioning mechanism for the cassette mold 22. The positioning pin 74 and the pin receiving hole 75 are slightly tapered.

  That is, as described above, the cassette mold 22 is a single-opening type composed of a fixed mold piece 221 and a movable mold piece 222, and the movable mold piece 222 abuts on the fixed mold piece 221 to form a cavity. The

  The movable mold piece 222 and the fixed mold piece 221 are structured to be clamped by the fixed die plate 211 and the movable die plate 213, and the movable die plate 213 is configured to move loosely on the tie bar 40, In order to increase the combination accuracy of the movable mold piece 222 and the fixed mold piece 221, it is necessary to increase the clamping accuracy and the loose fitting accuracy.

  If the clamping accuracy and loose fitting accuracy are obtained, the machining accuracy and the assembly accuracy are required to be high, which causes a cost increase. Therefore, in the present invention, the movable die piece 222 is not obtained without obtaining the clamping accuracy and the loose fitting accuracy. Is in contact with the fixed mold piece 221, and the positioning pin 74 is guided and combined with the pin receiving hole 75 so that the assembly accuracy of the cassette mold 22 can be secured.

  The movable die plate driving mechanism in the mold clamping housing 212 moves the movable die plate 213 forward and backward by rotating the mold clamping ball screw 23 screwed into the ball screw nut 24 attached to the movable die plate 213 and the mold clamping ball screw 23. The movable die plate drive unit 27 generates a predetermined clamping force when the movable die plate 213 comes into contact with the fixed die plate 211.

  This movable die plate driving unit 27 is engaged with the motor 5, the worm gear 26 that obtains rotational power by the motor 5, meshes with the worm gear 26, reduces the rotational speed of the motor 5, and transmits it to the mold clamping ball screw 23. A worm wheel 25 is provided for advancing and retracting the movable die plate 213 to which the mold clamping ball screw 23 is screwed.

  Conventionally, it is common to use a reduction gear for the purpose of generating a reduction or a large torque, or a reduction gear is gained by combining a spur gear with a direct connection type combination of a ball screw and a large capacity motor. Therefore, there is a problem of increasing the size, and in addition, there is a problem that power consumption becomes large because current must always be supplied during holding.

  In the present invention, as described above, the scroll drive unit 42, the plunger drive unit 61, and the movable die plate drive unit 27 are configured by worm gears 15, 26, 37 and worm wheels 14, 25, 36, respectively. Since the reduction gear ratio reduction mechanisms are driven by the motors 4, 5, and 6 having a small drive capacity, the above-described problems do not occur, and downsizing and low power consumption are possible.

  By the way, in the injection molding apparatus described so far, the plasticizing block 11, the measuring block, the fixed die plate 211, the movable die plate 213, and the mold clamping housing 212 are each provided, and a single material is injection molded. Although described, the present invention is not limited to this, and can also be applied to the case of injection molding of a product made of two or more kinds of materials such as two-color molding.

  In this case, a plasticizing unit is formed from one plasticizing block 11 and a metering block, respectively, and a plurality of plasticizing units are provided so that different materials can be injected. A mold clamping unit moving section (not shown) for moving the mold clamping unit comprising one fixed die plate 211, a movable die plate 213 and a mold clamping housing 212 so that the material from the mold can be injected into the cavity of one mold. Provide.

  Then, the multi-color molding can be easily performed by moving the mold clamping unit in accordance with each plasticizing unit injecting the material by the mold clamping unit moving portion.

The injection molding apparatus according to the present invention can be applied to an apparatus for producing a product by injection molding magnetic powder, iron powder, or ceramic coated with a thermoplastic resin, a heat effect resin, wax, or a binder.
It can also be used as a part manufacturing and supply device for assembly lines, as a testing device that can be placed on the table for research and experimentation.
Incidentally, the external dimensions of a molding machine having a mold clamping force of 1 tf and an injection pressure of 3,000 kgf / cm ² can be configured with a machine width of 12 cm, a machine height of 12 cm, and a machine length of 36 cm.
Furthermore, two or more plasticizing / injecting units are mounted on the mold clamping device of an injection molding machine that can rotate or slide the movable mold on the movable die plate 213, and two or more kinds of materials or colored materials are mixed and molded. Different materials and two-color molding can be developed by the injection molding method.

1 is a perspective view of an injection molding apparatus according to the present invention. It is sectional drawing. It is a figure which shows the structure of a scroll. It is a figure which shows the structure of a barrel. It is a figure which shows the cross-sectional structure of a barrel. It is a figure which shows the structure of a hot runner. It is a reverse view of a measurement block. It is sectional drawing which shows the principal part of a measurement delivery mechanism, and a perspective view which shows the structure of an injection plunger. It is a figure which shows the detailed structure of the injection plunger at the time of using the ball | bowl of a spherical body as a valve body. It is a figure which shows the detailed structure of the injection plunger at the time of using a truncated cone shaped valve body. It is a figure which shows the structure of a metal mold | die.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plasticization part 2 Mold part 3 Metering injection part 4, 5, 6 Motor 11 Plasticization block (body)
12 Scroll 13 Material input hole 14 Worm wheel 14, 25, 36 Worm wheel 15, 26, 37 Worm gear 22 Cassette mold 23 Ball screw for clamping 24 Ball screw nut 25 Worm wheel 26 Worm gear 27 Movable die plate drive unit 31 Weighing block (body )
32 Injection plunger 33 Ball screw for plunger 34 Dovetail groove 35 Ball screw nut 36 Worm wheel 37 Worm gear 39, 41 Injection cylinder 40 Tie bar 42 Scroll drive part 43 Spiral groove 44 Scroll shaft hole 45 Feed groove (kneading groove)
46 Scratch groove (guide groove)
47 Scroll action surface 48 Scroll side surface 49 Drive part engaging groove 50 Thrust bearing 52 Barrel pocket 53 Cooling water channel 54 Heat insulating material 55 Cooling water channel 57 Hot runner 58 Runner tube 59 (59a-59c) Nozzle 61 Plunger driving part 64 Notch 65 for delivery Introduction hole 66 Valve body 68 Thrust bearing 69 Tip hole 74 Positioning pin 75 Pin receiving hole 76 Runner receiving hole 78 Clamper 79 Clamp groove 80 Clamp claw 81 Clamp bolt 84 Heater hole 91 Extruding part 92 Extruding pin 93 Support plate 94 Extruding plate 95 Support rod 97 Spring 98 Thrust bearing 99 Head 100 Nut biasing spring 101 Load cell 105 Head 106 Insertion hole 121 Barrel 211 Fixed die plate (fixed side member)
212 Clamping housing (fixed side member)
213 Movable die plate (movable side member)
221 Fixed mold piece (fixed side member)
222 Movable mold piece (movable side member)

Claims (17)

An injection molding apparatus for injecting a plasticized material into a mold cavity to inject a product,
A plasticizing block in which a plasticizing pumping mechanism for heating and plasticizing the material and pumping the material while kneading is provided;
A metering block that is closely connected to the plasticizing block and provided therein with a metering delivery mechanism for metering and delivering the material pumped by the plasticizing pumping mechanism;
A fixed die plate provided with an injection mechanism for injecting into the cavity the material metered and delivered by the metering mechanism;
A movable die plate that advances and retreats toward the fixed die plate to make the cavity substantially closed when abutting against the fixed die plate;
The movable die plate is fixedly spaced apart from the fixed die plate by a plurality of tie bars guided, and the movable die plate is moved forward and backward with respect to the fixed die plate, and the movable die plate is fixed. An injection molding apparatus comprising: a mold clamping housing having a movable die plate drive mechanism that generates a predetermined mold clamping force when abutting against the die plate. The plasticizing pumping mechanism is
A barrel that heats and plasticizes the material;
A spiral groove that conveys the material is formed and rotated while being in contact with the barrel, thereby promoting plasticization and kneading of the material in the spiral groove, and sending it to an injection cylinder formed at the center of rotation. Scrolling columnar rotator,
The injection molding apparatus according to claim 1, further comprising a scroll driving unit that rotates the scroll. A spiral groove in the scroll,
A cutting groove formed by cutting an end mill parallel to the rotation axis of the scroll and cutting the end mill on the side surface of the rotating body;
Continuing with the scraping groove, it is formed by cutting the front surface of the rotating body into a spiral shape so as to be reduced toward the center of rotation, and is used to transport, plasticize, knead, and pump the scraped material. The injection molding apparatus according to claim 2, comprising a groove.   The injection molding device according to claim 2 or 3, wherein each contact surface of the scroll and the barrel is formed in a conical shape.   5. The injection molding apparatus according to claim 4, wherein each contact surface of the scroll and the barrel is formed in a concave conical shape that is recessed toward the scroll side. The scroll driving unit is
A worm gear that obtains rotational power by a motor;
And a worm wheel that meshes with the worm gear to reduce the rotational speed of the motor and that removably engages the scroll via a heat insulating plate to rotate the scroll at the reduced rotational speed. The injection molding apparatus according to any one of claims 2 to 5. The metering mechanism is
An injection plunger inserted through the injection cylinder;
A plunger ball screw detachably engaged with the injection plunger by a dovetail groove;
And a plunger driving unit that applies a feed force of the material pressure-fed to the injection plunger by driving the plunger ball screw to cause the injection plunger to move in the injection cylinder. Item 7. The injection molding apparatus according to any one of Items 1 to 6. The plunger drive
A worm gear that obtains rotational power by a motor;
A worm wheel that meshes with the worm gear and decelerates the rotational speed of the motor and transmits it to the plunger ball screw, thereby causing the injection plunger, which is detachably engaged with the plunger ball screw, to move the piston. The injection molding apparatus according to claim 7. A tip hole formed by drilling the tip of the injection plunger;
An introduction hole formed by grooving on the side surface in the longitudinal direction and a groove end on the distal end side communicating with the distal end hole;
A delivery notch formed by notching a tip hole in the longitudinal direction and delivering material from the tip hole;
When the pressure on the delivery notch side becomes higher than the pressure on the introduction hole side, the communication between the delivery notch and the introduction hole is blocked and the material is injected. And a valve body that enables the material to be injected by connecting the delivery notch and the introduction hole when the pressure on the delivery notch side becomes lower than the pressure on the introduction hole side. Item 9. The injection molding apparatus according to Item 7 or 8. The injection mechanism is
A hot runner into which the material delivered by the injection plunger flows,
A nozzle that injects material into the cavity by being selected according to the product to be injection molded and attached to the tip of the hot runner;
The injection molding apparatus according to any one of claims 1 to 9, further comprising a hot runner hole that detachably accommodates the hot runner and the nozzle. The movable die plate drive mechanism
A ball screw for clamping to be screwed with a ball screw nut attached to the movable die plate;
A worm gear that obtains rotational power by a motor;
11. An injection molding apparatus according to claim 10, further comprising: a worm wheel that meshes with the worm gear to reduce the rotational speed of the motor and transmit the speed to the clamping ball screw to advance and retract the movable die plate. . The mold that forms the cavity is
A fixed mold piece attached to the fixed die plate;
A movable mold piece that is attached to the movable die plate and forms a cavity in a substantially closed space when the movable die plate contacts the fixed die plate;
A taper pin formed on one of the movable mold piece or the fixed mold piece;
2. A taper hole formed in the other mold piece, wherein the taper pin is inserted and aligned when the movable mold piece abuts on the fixed mold piece. The injection molding apparatus of any one of thru | or 11. An extruding part to which a plurality of extruding pins provided so as to pass through the movable die piece and to be inserted into the cavity;
A spring that normally biases the pushing portion so that the head of the pushing pin forms the wall surface of the cavity;
When the movable die plate is formed on the movable die plate and the movable die plate moves backward toward the mold clamping housing by a predetermined amount or more, the head of the ball screw for mold clamping is inserted into contact with the push-out portion, and the push-out portion is The injection according to any one of claims 1 to 12, further comprising an insertion hole that allows the injection-molded product in the cavity to be pushed out by being pushed against the spring against the spring. Molding equipment.   A plurality of plasticizing units each including one plasticizing block and a weighing block are provided, and one mold clamping unit including one fixed die plate, a movable die plate and a mold clamping housing is provided, and The mold clamping unit moving part which moves the said mold clamping unit corresponding to each plasticization unit so that a different material can be inject | poured into one cavity is provided. Injection molding equipment. It is a scroll for an injection molding apparatus that transports the material by scraping it, and at that time, promoting plasticization and kneading of the material to pump the plasticized material,
The scroll is formed by cutting an end mill parallel to the rotation axis of the end mill on the side surface of the rotating body,
Continuing with the scraping groove, it is formed by cutting the front surface of the rotating body into a spiral shape so as to be reduced toward the center of rotation, and is used to transport, plasticize, knead, and pump the scraped material. A scroll for an injection molding apparatus, comprising a spiral groove including a groove.   The scroll for an injection molding apparatus according to claim 15, wherein a surface formed by connecting groove top portions of the feed grooves in the scroll has a conical shape.   The scroll for an injection molding apparatus according to claim 16, wherein a surface formed by connecting groove top portions of the feed groove in the scroll has a concave conical shape that is recessed toward the center thereof.

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