JPWO2007034549A1 - Injection molding equipment using reduction mechanism - Google Patents

Abstract

The plasticizing unit 10 converts the rotational motion of the scroll motor into the eccentric rotational motion by the first crank, and transmits the eccentric rotational power to the first eccentric motion gear 124. Further, a first regulating pin 130 having one end fixed to the first eccentric movement gear 124 and the other end loosely fitted to the plasticizing housing 101 is provided. Then, the rotation of the first eccentric movement gear 124 is restricted, and the loose fitting portion moves so as to allow the eccentric rotational movement, thereby causing the first eccentric movement gear 124 to eccentrically move. The first eccentric movement gear 124 partially meshes with the teeth in the eccentric direction, and the partial meshing position rotates in accordance with the change in the eccentric direction of the first eccentric movement gear 124. A first rotation gear 110 that rotates by receiving rotational power from one eccentric movement gear 124 is provided, and the first rotation gear 110 is provided integrally with the scroll 106. As a result, a speed reduction mechanism that can reduce power transmission loss to the limit with an inexpensive and simple configuration is configured.

Description

  The present invention relates to a speed reduction mechanism that amplifies rotational power by decelerating the rotational speed of power output from a power generation source and transmits it to a driven body, and an injection molding apparatus using the same.

  The injection molding apparatus includes a mold clamping unit 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. In this mold clamping part, it is necessary to mold the mold at a high pressure, and it is necessary to inject a plasticized material at a high pressure in the injection part into the cavity. In the plasticizing part, even if the material is plasticized, the viscosity is very high, so it is necessary to pump at a high pressure. In order to generate such a large amount of power, a method of driving by decelerating the output of a large motor with a reduction mechanism has been conventionally employed.

  However, in such an injection molding apparatus, the enlargement of each element increases the size of the injection molding apparatus, requiring a large installation space and increasing the amount of material remaining in the apparatus, resulting in a lot of waste. Was pointed out.

  Therefore, the inventor of the present application has proposed an injection molding apparatus that is innovatively miniaturized by reducing the size of each element and by reducing the size of a motor and a speed reduction mechanism as a power source (Patent Document 1). reference).

For example, a servo motor or a step restricting ping motor is adopted as a motor as a power source, and a speed reduction mechanism is constituted by a worm gear and a worm wheel. Servo motors, etc. are much smaller than conventional induction motors, and electrical control can be performed with high precision, enabling miniaturization of the power system and control system, and miniaturization of injection molding equipment. In addition, the reduction mechanism composed of a worm gear and a worm wheel contributes to a reduction in size by obtaining a large reduction ratio with a small number of parts.
Japanese Patent Application No. 2005-85249

  However, the speed reduction mechanism consisting of the worm gear and the worm wheel transmits power while the teeth of the worm gear and the teeth of the worm wheel slide, so there is a power transmission loss due to this sliding, and it is desirable that there is no margin in motor capacity. In some cases, it is impossible to obtain the motive power, and there is a problem that tooth wear due to sliding is intense and maintenance frequency increases.

  Of course, it is possible to suppress the occurrence of such problems by setting the motor capacity to a large value and using gears with teeth treated with titanium coating or the like. This is a direction opposite to the direction in which the injection molding is performed, and causes an increase in the cost of the injection molding apparatus.

  Accordingly, an object of the present invention is to provide a speed reduction mechanism that can reduce power transmission loss to the minimum with an inexpensive and simple configuration, and an injection molding apparatus using the same.

  In order to solve the above-described problem, the speed reduction mechanism according to claim 1 is a speed reduction mechanism that amplifies the rotational power by decelerating the rotational speed of the power output from the power generation source, and transmits the amplified power to the driven body. A crank that converts rotational power from a power generation source into eccentric rotational power, an eccentric motion gear that transmits eccentric rotational power from the crank, and a loose-fitting hole is formed in the eccentric motion gear. Is loosely fitted in the loose fitting hole and the other end is fixed to the fixed member fixed in position, or the loose fixed hole is formed in the fixed member, and one end is loosely fitted in the loose fitting hole. A regulation pin that regulates the rotation of the eccentric motion gear while allowing the eccentric motion of the eccentric motion gear within a range in which the other end is fixed to the eccentric motion gear and moves within the loose fitting hole, Formed integrally with the driven body and on the center side of the eccentric gear Or disposed so as to include the eccentric movement gear on the inside thereof, and partially meshed with a tooth portion in the eccentric direction of the eccentric movement gear, and to change in the eccentric direction of the eccentric movement gear. Accordingly, the rotation is caused by the rotation of the partial meshing position to receive rotation power and rotate.

  In the speed reduction mechanism according to claim 2, the driven body is a ball screw, and a rotation gear is formed on the ball screw shaft or the ball screw nut of the ball screw.

  An injection molding apparatus according to a third aspect of the present invention is an injection molding apparatus including a plasticizing portion including a scroll driving mechanism that drives a scroll when the material is plasticized and fed by a scroll. A scroll having a speed reduction mechanism, in which the driven member is compressed toward the rotation center axis, and the material in the spiral groove is pumped toward the rotation center axis, and the fixing member is a casing of the plasticizing portion. The resulting plasticized housing.

  According to a fourth aspect of the present invention, there is provided an injection molding apparatus comprising: a plunger drive mechanism that drives the plunger when the plasticized material in the injection cylinder is injected into the cavity of the extrusion mold by the plunger that forms the piston of the injection cylinder. An injection molding apparatus having an injection part, wherein the plunger driving mechanism has a speed reduction mechanism, and the driven body engages with a ball screw shaft whose tip is a plunger, and the ball screw shaft is free to move. An injection-side engagement member that allows advancement and retraction in the axial direction while restricting rotation. The injection-side engagement member and the rotation gear are integrally formed, and the fixing member forms an injection housing that forms a casing of the injection unit. It is.

  The injection molding apparatus according to claim 5 further includes a plunger drive mechanism that drives the plunger when the plasticized material in the injection cylinder is injected into the cavity of the extrusion mold by the plunger that forms the piston of the injection cylinder. An injection molding apparatus having an injection part, wherein the plunger drive mechanism has a speed reduction mechanism, and the driven body is a ball screw nut screwed into a ball screw shaft whose tip is a plunger, and the ball screw nut And the rotation gear are integrally formed, and the fixing member forms an injection housing that forms a casing of the injection portion.

  The injection molding apparatus according to claim 6 is configured such that when the movable mold of the fixed mold and the movable mold movable with respect to the fixed mold is driven and clamped, An injection molding apparatus having a mold clamping unit having a mold clamping drive mechanism for opening and closing the mold, wherein the mold clamping drive mechanism has a speed reduction mechanism, and at this time, the driven body is connected to the movable mold at the tip. A mold clamping side engaging body that engages with the ball screw shaft and rotates the ball screw shaft. The mold clamping side engaging body and the rotation gear are integrally formed, and the fixing member forms a casing of the mold clamping portion. This is a tightening housing.

  A speed reduction mechanism according to the present invention is a speed reduction mechanism that amplifies rotational power by decelerating the rotational speed of power output from a power generation source and transmits the rotational power to a driven body. A crank for converting to eccentric rotational power, an eccentric motion gear to which eccentric rotational power is transmitted from the crank, a loose fitting hole is formed in the eccentric motion gear, and one end is loosely fitted in the loose fitting hole At the same time, the other end is fixed to a fixed member whose position is fixed, or a loose fitting hole is formed in the fixed member whose position is fixed, and one end is loosely fitted in the loose fitting hole and the other end is an eccentric gear. A fixed pin that is integrally formed with the driven body and a regulation pin that regulates the rotation of the eccentric gear while allowing the eccentric gear to move in the range in which the pin moves within the loose hole. And arranged on the center side of the eccentric movement gear or the eccentric movement It is arranged so as to include a vehicle inside, and partially meshes with the tooth portion in the eccentric direction of the eccentric motion gear, and the partial meshing position according to the change in the eccentric direction of the eccentric motion gear Since it consists of a rotating gear that rotates by receiving rotational power by rotating, it becomes possible to reduce power transmission loss to the limit with an inexpensive and simple configuration. It becomes possible to increase the price and improve the reliability.

It is sectional drawing of the injection molding apparatus which concerns on this invention. It is a cross-sectional perspective exploded view of a plasticization part. It is a figure which shows the structure of a scroll. It is a figure applied to description of operation | movement of a deceleration mechanism. It is a cross-sectional perspective exploded view explaining a check valve mechanism. It is a figure applied to description of operation | movement of a check valve mechanism. It is a cross-sectional perspective exploded view of an injection part. It is a section perspective exploded view of a mold clamping part. It is a figure at the time of integrally forming the ball screw nut and eccentric motion gear of the speed-reduction mechanism in an injection part. It is a figure at the time of integrally forming the ball screw nut and eccentric motion gear of the speed reduction mechanism in the mold clamping unit. It is a figure which shows the example in the case of carrying out loose fitting or fitting to a to-be-driven body, without making a regulation pin loosely fitting or fitting to fixing members, such as a plasticization housing. It is a figure showing an example at the time of using a plurality of eccentric motion gears. It is a figure which shows the inclusion relationship of the tooth | gear in an eccentric gear and a rotation gear.

Explanation of symbols

10 plasticizing part; 20 injection part 30 mold clamping part; 40 cassette mold; 101 plasticizing housing 102 fixed die plate; 104 barrel; 105 spiral groove 106 scroll; 107 scroll drive mechanism; 108 check valve mechanism 109 scroll shaft hole; 110 first rotating gear; 111 scroll working surface 112 scroll side surface; 113 feeding groove; 114 scraping groove 120 scroll motor; 121 check valve; 123 first restriction pin fixing hole 124 (124a to 124c) first 125 (129a to 125c) First crank 126 Motor shaft; 128 Tube portion; 129 Crank portion 130 First restriction pin; 131 Head; 132 Flange 133 (133a to 133c) First free fitting hole; Valve receiving member 136 One-way clutch; 137 Clutch insertion part; 139 Valve pocket 140 Open / close end part; 141 Engagement part; 142 Rotation stop part 144 Rotation stop hole; 145 Clutch attachment part; 146 Taper part 147 Engaged part; 150 taper fitting portion; 151 receiving member insertion portion 152, 153 step portion; 201 injection cylinder; 202 plunger 203 plunger driving mechanism; 204 runner tube; 206 injection motor 207 second pulley; 208 second eccentric motion gear; 211 Rotating gear 210 Second ball screw shaft; 211 Injection housing; 213 Second ball screw shaft 214 Second ball screw nut; 215 Through hole; 216 Second crank 217 Head; 219 Second ball screw shaft insertion hole; 220 Nut engaging portion 222 2nd Fitting hole; 223 second restriction pin fixing hole; 225 second ball screw shaft engaging portion 230 second restriction pin; 301 mold clamping housing; 302 movable die plate 303 mold clamping drive mechanism; 304 diver; 311 third ball screw shaft 312 type Tightening motor; 313 Female screw; 314 Third pulley 315 Third restriction pin; 316 Cylindrical hole; 317 Third rotation gear 318 Storage portion; 319 Engagement hole; 320 Bolt hole 321 Third restriction pin fixing hole; 323 fixing bolt 324 insertion hole; 325 third loose hole; 326 head 327 third crank; 328 third ball screw nut 401 movable mold; 402 fixed mold; 403 positioning pin 404 restriction pin receiving hole

  Embodiments of the present invention will be described with reference to the drawings. 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.

  Further, as will be described later, the speed reduction mechanism according to the present invention includes a crank that converts rotational power from a power generation source into eccentric rotational power, an eccentric motion gear that transmits eccentric rotational power from the crank, A loose fitting hole is formed in the eccentric gear, and one end is loosely fitted in the loose fitting hole and the other end is fixed to a fixed member fixed in position, or a loose fitting hole is formed in the fixed member fixed in position. It is formed, and one end is loosely fitted in the loose fitting hole and the other end is fixed to the eccentric movement gear. The eccentric movement of the eccentric movement gear is allowed within the range in which the pin moves in the loose fitting hole. However, the regulating pin for regulating the rotation of the eccentric gear and the driven body are formed integrally with the driven gear and arranged on the center side of the eccentric gear or arranged to include the eccentric gear on the inside. And is partially meshed with the tooth portion in the eccentric direction in the eccentric gear. The rotation gear rotates the rotary power Te receiving by partial meshing position in response to changes in the direction of eccentricity of the eccentric motion gear rotates is a main configuration.

  In the injection molding apparatus, the speed reducer mechanism is used for a scroll driving mechanism, a plunger driving mechanism, and a mold clamping driving mechanism. At this time, similar members (crank, restriction pin, eccentric motion gear, rotation gear, etc.) in the scroll drive mechanism, the plunger drive mechanism, and the mold clamping drive mechanism are distinguished as first to third, respectively. For example, a crank in the scroll driving mechanism is described as a first crank, a crank in the plunger driving mechanism is described as a second crank, and a crank in the mold clamping driving mechanism is described as a third crank. The power generation source corresponds to a scroll motor, an injection motor, and a mold clamping motor.

  Note that the application of the speed reduction mechanism according to the present invention is not limited to the injection molding apparatus, and it is a requirement that the free gear is formed integrally with the driven body, and that the speed reduction drive system of an automobile or the speed reduction of an electrical device is used. It is added that it can be applied to general deceleration devices such as drive trains.

  FIG. 1 is a cross-sectional view of such an injection molding apparatus. The injection molding apparatus includes a movable mold 401 and a fixed mold 402, and a cavity K, which is a space into which plasticized material is injected on the abutting surfaces. Mold 40 to be formed, plasticizing part 10 for heating and plasticizing the material and kneading the material, and injection for injecting the plasticized material in injection cylinder 201 into cavity K The mold clamping part 30 which opens and closes the part 20 and the mold 40 is the main component.

  FIG. 2 is an exploded perspective view showing a main part of the plasticizing part 10, which has a plasticizing housing 101 and a fixed die plate 102, and the plasticizing housing 101 has a material charging hole 103 into which a material such as pellets is charged. Is formed.

  In the plasticizing housing 101 and the fixed die plate 102, a barrel 104 for heating the material charged from the material charging hole 103 and a spiral groove 105 for conveying the material are formed and rotated while contacting the barrel 104. A material in the spiral groove 105 is conveyed, stirred, plasticized, kneaded, and after plasticization, a scroll 106 is pumped in the direction of the rotation center axis with a Weisenberg effect, and a scroll driving mechanism 107 that rotationally drives the scroll 106. A check valve mechanism 108 is provided for controlling injection and backflow of the plasticized material.

  As shown in FIG. 3, the scroll 106 is a rotating body having a substantially short cylindrical shape, and a spiral groove 105 is formed on the side of the rotating body that contacts the fixed die plate 102. The spiral groove 105 is formed in a plurality of strips (in the case of one strip in FIG. 2) so that the scroll shaft hole 109 formed in the rotation shaft contracts in accordance with the rotation direction of the scroll 106, and the back surface thereof is a recess 116. The first rotation gear 110 is formed on the inner surface of the recess 116. A check valve 121 is mounted in the scroll shaft hole 109.

Hereinafter, the surface where the scroll 106 is in contact with the fixed die plate 102 is referred to as a scroll action surface 111, and the side surface thereof is referred to as a scroll side surface 112. Further, the spiral groove 105 formed on the scroll working surface 111 is referred to as a feeding groove 113, and the spiral groove 105 formed on the scroll side surface 112 is referred to as a scraping groove 114. Accordingly, the spiral groove 105 is constituted by the scraping groove 114 and the feeding groove 113.
The scroll action surface 111 is formed to have a concave conical shape close to a plane having an apex angle θ of θ = 176 ° to 174 ° to generate a direct pressure (N), thereby enabling the material to be pumped. . Of course, it is good also as the convex cone shape of the same angle.

The barrel 104 is provided with a plurality of heaters (not shown) for heating the material inside, and the surface on the scroll 106 side is formed in a shape in close contact with the scroll action surface 111, and is plasticized on the central axis thereof A flow path 115 is formed.
In addition, a cooling water channel 117 that forms a flow path of the cooling water is formed so that the plasticizing housing 101 and the fixed die plate 102 and various members included therein are not heated by the heat of the barrel 104, and the heat insulating material. 118 is provided as appropriate.

  The scroll 106 is rotatably disposed in the plasticizing housing 101 via a bearing A, and a scroll driving mechanism 107 that reduces the rotation speed of the scroll motor 120 and transmits it to the scroll 106 is provided.

  The scroll drive mechanism 107 has an annular first eccentric motion in which teeth that mesh with the first rotation gear 110 are formed on the outer peripheral surface and a plurality of first restriction pin fixing holes 123 are inserted in the thickness direction. A gear 124, a first restriction pin 130 that is inserted into the first restriction pin fixing hole 123, and a sleeve-shaped first crank 125 that transmits rotational power to the first eccentric movement gear 124, are scrolled to the first crank 125. A motor shaft 126 of the motor 120 is mounted.

  The first crank 125 is composed of a cylindrical portion 128 into which the motor shaft 126 is inserted, and a crank portion 129 that is eccentric with respect to the cylindrical portion 128. One eccentric motion gear 124 is inserted, and a bearing B is externally inserted into the cylindrical portion 128 so as to be inserted into the plasticizing housing 101.

The plasticized housing 101 is fixed to the fixed die plate 102, and the flange 132 is screwed to the plasticized housing 101.
The flange 132 is provided with a first loose-fitting hole 133 in which the head 131 of the first restriction pin 130 is loosely fitted and the movement of the first eccentric movement gear 124 is restricted.

  With such a configuration, the rotational motion of the motor shaft 126 is transmitted to the first crank 125, the crank portion 129 performs eccentric rotational motion, and this eccentric rotational motion is the first eccentric motion gear via the bearing C. 124.

  FIG. 4 is a schematic diagram for explaining such a speed reduction mechanism. When the first eccentric movement gear 124 is eccentric by the first crank 125, the tooth portion of the first eccentric movement gear 124 in the eccentric direction and the first eccentric movement gear 124 are shown. The tooth part of 1 rotation gear 110 will be in part meshing, and the teeth of other parts will be in the separated state.

  When the eccentric direction rotates in such a state, the head of the first restricting pin 130 moves along the inner peripheral surface of the first loose-fitting hole 133 to move the first eccentric movement gear 124 and the first rotation gear 110. The part that meshes with this rotates. Since the rotation of the first eccentric movement gear 124 is restricted by the first restriction pin 130, the change in the meshing position is allowed by the rotation of the first rotation gear 110, and the rotational power of the scroll motor 120 is the first. It is transmitted to the first rotation gear 110 at a reduction ratio determined by the first rotation gear 110 and the first eccentric movement gear 124.

In the speed reduction mechanism including the first rotation gear 110, the first eccentric movement gear 124, and the first restriction pin 130 that restricts the movement of the first eccentric movement gear 124, the teeth of the first rotation gear 110 and the first eccentric gear The teeth of the movement gear 124 are both parallel teeth, and there is almost no sliding between the teeth as in the worm gear and the worm wheel, so the tooth wear loss can be reduced and the power loss associated with the sliding is greatly increased. It becomes possible to suppress.
Further, since the movable part is configured to contact other members via the bearings A to C, the power transmission loss in the movable part can be greatly reduced.

  The check valve mechanism 108 controls whether or not the plasticized material is delivered from the scroll 106 to the injection unit 20, and the material injected toward the cavity K by the injection unit 20 flows back to the plasticization unit 10. As shown in FIG. 5, it comprises a check valve 121, a valve screw 135, a one-way clutch 136, a valve screw storage 151, and the like.

  The end of the check valve 121 on the barrel 104 side abuts on a conical valve pocket 139 that is an opening of a flow path 115 that forms a flow path of the material that flows through the barrel 104, and the valve pocket 139 is The open / close end 140 is formed in a closed shape, and the other end of the check valve 121 is formed with a threaded screw 141, and a rotation stop 142 is formed in the middle of these. The border between the rotation stop portion 142 and the screw portion 141 is a contact portion 152 that forms a step.

  The rotation stop portion 142 is formed by cutting the check valve 121 into, for example, a D shape, and a hole (rotation stop hole) 144 having the same shape as the cross-sectional shape of the rotation stop portion 142 is formed in the scroll shaft hole 109. . The rotation stop portion 142 of the check valve 121 is inserted into the rotation stop hole 144 so that the free rotation of the check valve 121 is restricted and the check valve 121 can advance and retreat in the axial direction.

  The valve screw 135 includes a clutch insertion tube portion 145 into which the one-way clutch 136 is inserted and a taper portion 146 formed so that the vicinity of one end thereof is reduced toward the motor shaft 126. A female screw portion 147 to which the portion 141 is screwed is formed.

  On the other hand, the motor shaft 126 is formed with a valve screw storage portion 151 including a clutch storage hole 137 for storing the one-way clutch 136 and a tapered portion storage hole 150 for storing the tapered portion 146.

  Then, as shown in FIG. 6A, the motor shaft 126 rotates in a predetermined direction (a direction in which the plasticized material is injected). In this state, the taper portion 146 of the valve screw 135 is press-fitted into the taper portion accommodation hole 150 of the valve screw housing portion 151, and the one-way clutch 136 is in a free state. Therefore, when the motor shaft 126 rotates, the taper portion housing is accommodated. The valve screw 135 is rotated by friction between the hole 150 and the taper portion 146 of the valve screw 135, and the check valve 121 moves toward the motor shaft 126 side by screwing the screw portion 141 and the female screw portion 147.

  As a result, the open / close end 140 of the check valve 121 is separated from the valve pocket 139, the valve pocket 139 is opened, and the material is sent into the injection cylinder 201 through the flow path 115 as shown in FIG. The In FIG. 6, a solid line arrow L1 indicates the direction in which the check valve moves, and a solid line arrow L2 indicates the direction in which the plunger 202 moves. A dotted arrow L3 indicates the material flow.

  When the contact portion 152 of the check valve 121 contacts the contact portion 153 of the scroll shaft hole 109, the movement of the check valve 121 is regulated by this contact, and the valve screw 135 is attracted to the check valve 121. As shown in the enlarged view of FIG. 6B, a minute gap δ is generated between the tapered portion 146 and the tapered portion receiving hole 150, and the press-fitted state is released. This gap is a gap that allows the tapered portion 146 and the tapered portion accommodation hole 150 to be idle.

  When the taper portion 146 and the taper portion accommodation hole 150 are idle, the rotational driving force to the check valve 121 is not transmitted, so that the scroll 106 can continue to rotate and continue to inject material.

  When a predetermined amount of material is fed into the injection cylinder 201, the scroll motor 120 is reversely rotated as shown in FIG. Since the rotation direction is a direction in which the one-way clutch 136 functions as a clutch state, the rotation of the motor shaft 126 is transmitted to the valve screw 135 via the one-way clutch 136, and the check valve 121 moves toward the valve pocket 139 and opens and closes the end portion. 140 abuts against the valve pocket 139 to close the opening.

  When the open / close end 140 abuts the valve pocket 139, the check valve 121 cannot move any further, so that the valve screw 135 moves to the motor shaft 126 side, and the taper portion 146 is pushed into the taper portion accommodation hole 150, and FIG. ), And returns to the state shown in FIG.

  In a state where the valve pocket 139 is closed, even if the plunger 202 injects the material in the injection cylinder 201, the material does not flow back to the scroll 106 side due to the injection pressure.

  Thus, since the check valve 121 can be reliably operated with a simple configuration using inexpensive parts, the reliability is improved and the check valve 121 moves like a piston in the scroll shaft hole 109. Therefore, when the injection molding apparatus is started, the problem that the material enters the gap or the like during the previous operation and the movement of the check valve 121 becomes worse is solved.

  Further, since the drive source of the check valve 121 is the scroll motor 120 that drives the scroll 106, it is possible to reduce the cost by downsizing the injection molding apparatus and reducing the number of parts by using the power source together.

  As shown in detail in FIG. 7, the injection unit 20 is provided in the above-described injection cylinder 201, the plunger 202 attached to the injection cylinder 201, the plunger drive mechanism 203 that drives the plunger 202, and the fixed die plate 102. And a runner tube 204 for injecting the material from the injection cylinder 201 into the cavity K.

The plunger drive mechanism 203 is provided in the injection housing 211 with a second pulley 207, a second eccentric motion gear 208, a second rotation gear 209, and a second ball screw shaft 210 to which power of the injection motor 206 is transmitted as main components. It has been.
The tip of the second ball screw shaft 213 is a plunger 202 that forms the piston of the injection cylinder 201, and the rear end of the second ball screw shaft 213 has an asymmetric cross section (for example, D shape) with respect to the axis.

  The second pulley 207 is sandwiched by a pair of bearings D and rotates freely. A through hole 215 into which the head 217 of the second ball screw shaft 213 is inserted is formed inside. The inner peripheral surface of the end of the second pulley 207 on the second ball screw shaft 213 side is formed as a cylindrical surface coaxial with the rotational axis of the second pulley 207, and the outer peripheral surface is a cylinder that is eccentric with respect to the rotational axis. A second crank 216 comprising a surface is formed. Note that a bearing E is extrapolated to the second crank 216.

The injection housing 211 is provided with a second ball screw shaft insertion hole 219 and a nut engaging portion 220, and a plurality of second loose fitting holes 222 are provided on the end surface on the injection motor 206 side (second pulley 207 side). .
When the second ball screw nut 214 is mounted and stored in the nut engaging portion 220, the second ball screw nut 214 is fixed to the injection housing 211 with a screw (not shown).

  The second eccentric movement gear 208 is an annular gear having teeth formed on the inner peripheral surface and a plurality of second restricting pin fixing holes 223 formed in the thickness direction, and the second crank 216 via the bearing E. It is attached to.

  Further, the second rotation gear 209 has teeth formed on the outer peripheral surface and a second ball screw shaft engaging portion 225 through which the head 217 of the second ball screw shaft 213 is inserted and engaged at the center. A bearing F is extrapolated to the outer peripheral portion of the two-ball screw shaft engaging portion 225 and is inserted into the second eccentric movement gear 208.

  Then, when the second pulley 207 rotates, the second crank 216 performs an eccentric rotational motion, and the eccentric rotational motion is transmitted to the second eccentric motion gear 208. A second regulating pin 230 is fixed to the second eccentric movement gear 208, and its head is loosely fitted in a second loose fitting hole 222 provided in the injection housing 211. Since the head of the second restriction pin 230 moves eccentrically within a range in which it can move in the second loose-fitting hole 222, the second rotation gear 209 partially meshes while the rotation motion is restricted, and this meshing portion is By rotating, the second rotation gear 209 rotates.

  When the second rotation gear 209 rotates, the rotation is transmitted to the second ball screw shaft 213 by the engagement between the second ball screw shaft engaging portion 225 and the head 217 of the second ball screw shaft 213, and the second rotation gear 209 is rotated. When rotating in a certain direction, the plunger 202 moves so as to be extracted from the injection cylinder 201 and the inside of the injection cylinder 201 becomes empty, and when rotated in the opposite direction, the cylinder contents (material) of the injection cylinder 201 are pushed out.

  As shown in detail in FIG. 8, the mold clamping unit 30 includes a mold clamping housing 301, a movable die plate 302, and a mold clamping drive mechanism 303. The mold clamping housing 301 is connected to the fixed die plate 102 by a plurality of divers 304. The movable die plate 302 is inserted into the diver 304 and can be advanced and retracted by the mold clamping drive mechanism 303.

  The mold clamping drive mechanism 303 includes a third ball screw shaft 311, a mold clamping motor 312, a third pulley 314, a third restriction pin 315, a third eccentric movement gear 322, a third rotation gear 317, and the like. The end of the third ball screw shaft 311 on the third pulley 314 side is a head 326 having a cross section that is asymmetric (eg, D-shaped) with respect to the shaft center, and a female screw 313 is formed at the center thereof. Yes.

  The third pulley 314 is sandwiched by a pair of bearings I and is rotated by the rotational power of the mold clamping motor 312, and a third crank 327 is provided at the tip thereof. One end of the third crank 327 is formed with a cylindrical hole 316 that is coaxial with the rotation shaft of the third pulley 314, and the outer peripheral surface of the third crank 327 has a cylindrical shape composed of a circumferential surface eccentric to the rotation shaft. H is extrapolated. The cylindrical hole 316 is a hole for accommodating the head of the fixing bolt 323.

  The third crank 327 is housed in the housing portion 318 provided in the mold clamping housing 301 via the bearing I. The mold clamping housing 301 is formed with an insertion hole 324 through which the head 326 of the third ball screw shaft 311 is inserted and a third ball screw shaft 311 side surface on which the head of the third restriction pin 315 is loosely fitted. A plurality of loose fitting holes 325 are provided.

  The third eccentric gear 322 is an annular member in which teeth are formed on the outer peripheral surface and a plurality of third restricting pin fixing holes 321 are formed in the thickness direction. A crank 327 is inserted.

In the third rotation gear 317, teeth are formed on the inner peripheral surface of a member protruding from the surface on the third eccentric movement gear 322 side, and the head of the third ball screw shaft 311 is inserted on the other surface. An engagement hole 319 to be engaged is provided.
A bolt hole 320 through which the fixing bolt 323 is inserted is formed at the center of the third rotation gear 317. A head 326 of the third ball screw shaft 311 is attached to the engagement hole 319 and tightened with the fixing bolt 323. Thus, the third rotation gear 317 and the third ball screw shaft 311 are connected.

  The rotational power of the mold clamping motor 312 is transmitted as an eccentric rotational motion of the third crank 327 via the third pulley 314. This eccentric rotational movement is transmitted to the third eccentric movement gear 322 via the bearing H, and the teeth of the third rotation gear 317 and a part of the third rotation gear 317 according to the movement restriction of the third restriction pin 315 by the third loose fitting hole 325. Since the meshing position rotates in accordance with the eccentric direction, the third rotation gear 317 rotates, and accordingly, the third ball screw shaft 311 rotates.

The mold 40 is a cassette mold 40 composed of a movable mold 401 attached to the movable die plate 302 and a fixed mold 402 attached to the fixed die plate 102, and one of the molds 40 has a plurality of positions. A fixing pin 403 is provided, and a regulating pin receiving hole 404 into which the positioning pin 403 is fitted is provided in the opposite mold 40.
Furthermore, a runner receiving hole 406 into which the hot runner 405 is inserted is formed in the fixed mold 402 attached to the fixed die plate 102.

  The movable mold 401 is provided with a molded product extrusion mechanism 407. This molded product extrusion mechanism 407 is fixed to a support plate 409 to which a plurality of extrusion pins 408 provided so as to pass through the movable die 401 and to be inserted into the cavity K are fixed, and to the movable plate 409. A support rod 410 to be inserted into 401, a spring 411 that is inserted into the support rod 410 and biases the support plate 409 so that the head of the push pin 408 forms the wall surface of the cavity K at normal times, and the support plate 409 are fixed. And a thrust bearing 413 attached to the extrusion plate 412.

  Then, when the molded product push-out mechanism 407 takes out the injection-molded product, the third ball screw shaft 311 comes into contact with the thrust bearing 413 when the movable die plate 302 is moved backward toward the mold clamping housing 301 by a predetermined amount or more. Then, the support plate 409 is pushed toward the cavity K against the spring 411. Thereby, the injection molded product in the cavity K can be easily extruded by the extrusion pin 408.

  The thrust bearing 413 is provided so that the head of the third ball screw shaft 311 does not damage the push plate 412 and may be a thrust sliding bearing or the like.

In addition, the ball screw nut and the rotating gear in the injection unit 20 and the mold clamping unit 30 have separate structures. However, the present invention is not limited to this. For example, as shown in FIGS. 9 and 10, the ball screw nut and the eccentric motion gear of the speed reduction mechanism in the injection unit 20 and the mold clamping unit 30 may be integrally formed.
9 shows the case in the injection part 20, and FIG. 10 shows the case in the mold clamping part 30.
As a result, since the two members become the one member, the cost can be reduced and the device can be further downsized.

Further, the first restriction pin 130 to the third restriction pin 315 described so far are fixed to the first eccentric movement gear 124 to the third eccentric movement gear 322, and the first loose fitting provided in the plasticizing housing 101 or the like. Although it was the structure loosely fitted in the hole 133-the 3rd loose fitting hole 325, the reverse structure may be sufficient.
That is, the function of the first restricting pin 130 and the like is to perform the position restriction of the first eccentric movement gear 124 and the like with respect to the plasticizing housing 101 and the like which are fixing members. A restriction pin fixing hole 123 is formed to fix the first restriction pin 130 or the like, and a first loose fitting hole 133 or the like is formed in the first eccentric movement gear 124 or the like to loosely fit the first restriction pin 130 or the like. Will be able to carry out similar regulations.

Further, the regulation pin not only loosely fits or fits on a fixing member such as a plasticized housing, but also loosely fits or fits on a driven body 330 that rotates with an eccentric motion gear as shown in FIG. It may be a configuration.
In this case, the rotating gear described so far is fixed. The meshing relationship between the gear (fixed gear 331) and the third eccentric gear 322 does not change, and the third regulating pin 315 is loosely fitted or fitted to the driven body 330 fixed to the third ball screw shaft 311. Therefore, the rotational power is transmitted to the driven body 330 and the third ball screw shaft 311 rotates.

  Further, a bearing may be provided in order to avoid friction caused by the direct contact of the first restricting pins and the like that are loosely fitted in the loose fitting holes.

  Further, in the description so far, the eccentric gear and the rotation gear have a one-to-one relationship, and one is provided, but a configuration in which a plurality of eccentric gears are provided for one rotation gear. It is also possible to make it.

  For example, as shown in FIG. 12, n first eccentric motion gears 124a to 124c, bearings Ba to Bc, and first cranks 129a to 129c are provided (FIG. 12 shows three cases each). At this time, the first cranks 129 a to 129 c of 3 are shifted by an equal angle with respect to the rotation center of the motor shaft 126. Then, one end of the first restriction pin 130 is loosely fitted in the first loose fitting holes 133a to 133c of the first eccentric movement gears 124a to 124c, and the other end is fixed to the flange 132.

  With such a configuration, the first eccentric movement gears 124a to 124c are eccentric according to the phases of the first cranks 129a to 129c and partially mesh with the first rotation gear 110, respectively. In 110, rotational power is simultaneously transmitted from each of the first eccentric gears 124a to 124c, the power transmission point is axisymmetric, and smooth rotational power can be transmitted, and the same power can be transmitted. Since the power of each of the first eccentric gears 124a to 124c and the first cranks 129a to 129c is divided when transmitting to the one rotation gear 110, wear and the like can be suppressed.

  Further, the present invention is not limited to the inclusion relationship between the eccentric gear and the rotation gear. For example, in FIG. 10, the third eccentric gear 322 has internal teeth and the third rotation gear 317 has external teeth. However, as shown in FIG. 13, the third eccentric gear 322 has external teeth and the third rotation gear. The same effect can be obtained by using 317 as an internal tooth.

Further, in the above description, the mold clamping unit 30 and the like are configured to transmit the rotational power of the motor to the crank via a pulley, but may be configured to directly attach the crank to the motor shaft like a plasticizing unit.

The present invention relates to an injection molding apparatus using a speed reduction mechanism that amplifies rotational power by transmitting the rotational speed of power output from a power generation source and transmits it to a driven body.

  The injection molding apparatus includes a mold clamping unit 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. In this mold clamping part, it is necessary to mold the mold at a high pressure, and it is necessary to inject a plasticized material at a high pressure in the injection part into the cavity. In the plasticizing part, even if the material is plasticized, the viscosity is very high, so it is necessary to pump at a high pressure. In order to generate such a large amount of power, a method of driving by decelerating the output of a large motor with a reduction mechanism has been conventionally employed.

  However, in such an injection molding apparatus, the enlargement of each element increases the size of the injection molding apparatus, requiring a large installation space and increasing the amount of material remaining in the apparatus, resulting in a lot of waste. Was pointed out.

  Therefore, the inventor of the present application has proposed an injection molding apparatus that is innovatively miniaturized by reducing the size of each element and by reducing the size of a motor and a speed reduction mechanism as a power source (Patent Document 1). reference).

For example, a servo motor or a stepping motor is used as a power source motor, and a speed reduction mechanism is also composed of a worm gear and a worm wheel. Servo motors, etc. are much smaller than conventional induction motors, and electrical control can be performed with high precision, enabling miniaturization of the power system and control system, and miniaturization of injection molding equipment. In addition, the reduction mechanism composed of a worm gear and a worm wheel contributes to a reduction in size by obtaining a large reduction ratio with a small number of parts.
Japanese Patent Application No. 2005-85249

  However, the speed reduction mechanism consisting of the worm gear and the worm wheel transmits power while the teeth of the worm gear and the teeth of the worm wheel slide, so there is a power transmission loss due to this sliding, and it is desirable that there is no margin in motor capacity. In some cases, it is impossible to obtain the motive power, and there is a problem that tooth wear due to sliding is intense and maintenance frequency increases.

  Of course, it is possible to suppress the occurrence of such problems by setting the motor capacity to a large value and using gears with teeth treated with titanium coating or the like. This is a direction opposite to the direction in which the injection molding is performed, and causes an increase in the cost of the injection molding apparatus.

Therefore, an object of the present invention is to provide an injection molding apparatus using a speed reduction mechanism that can reduce power transmission loss to the limit with an inexpensive and simple configuration.

The speed reduction mechanism applied to the injection molding apparatus according to claim 1 amplifies the rotational power by decelerating the rotational speed of the power output from the power generation source and transmits it to the driven body. A crank that converts rotational power from the generation source into eccentric rotational power, an eccentric motion gear that transmits the eccentric rotational power from the crank, a loose fitting hole is formed in the eccentric motion gear, and one end is The loose fitting hole is loosely fitted to the fixing member whose other end is fixed, or the fixing member whose position is fixed is formed with a loose fitting hole, and one end is loosely fitted to the loose fitting hole and the other. A pin whose end is fixed to the eccentric gear, a regulation pin for restricting the rotation of the eccentric gear while allowing the eccentric gear to move in the range in which the pin moves within the loose fitting hole, Formed integrally with the drive body and arranged on the center side of the eccentric gear Or is arranged so as to include the eccentric motion gear on the inside, and partially meshes with a tooth portion in the eccentric direction of the eccentric motion gear, and according to a change in the eccentric direction of the eccentric motion gear. partial meshing position Te is made of a rotation gear accepted by rotates the rotational power by rotating.

An injection molding apparatus according to claim 1 includes a scroll driving mechanism that drives a scroll when the material is plasticized and fed by a scroll, and a check valve mechanism that controls injection of the plasticized material. the provided, comprising the scroll drive mechanism the speed reduction mechanism, the driven body, the material of the helical groove to reduce toward the rotation center axis is the scroll for pumping toward the center of rotation axis, said the fixing member consists of plasticized housing which forms a casing of the plasticizing unit, also a part portion of the check valve mechanism of the power source, is driven by the rotational power of the power source .

The injection molding apparatus according to claim 2 that cites claim 1 further includes the step of injecting the plasticized material in the injection cylinder into the cavity of the extrusion mold by the plunger that forms the piston of the injection cylinder. comprising an injection unit having a plunger drive mechanism for driving the plunger driving mechanism includes the reduction mechanism similar to other reduction mechanism (second reduction mechanism), driven member in the second reduction mechanism The injection-side engagement member and the rotation gear are integrated with an injection-side engagement member that engages with a ball screw shaft that forms a plunger at the tip and restricts the free rotation of the ball screw shaft while allowing it to advance and retreat in the axial direction. It is formed on, and consists of the injection housing fixing member in said second reduction mechanism forms the casing of the injection unit.

The injection molding apparatus according to claim 3 quoting claim 1 further includes the step of injecting the plasticized material in the injection cylinder into the cavity of the extrusion mold by the plunger forming the piston of the injection cylinder. comprising an injection unit having a plunger drive mechanism for driving the plunger driving mechanism includes the reduction mechanism similar to other reduction mechanism (second reduction mechanism), driven member in the second reduction mechanism the ball screw nut tip is screwed to a ball screw shaft constituting a plunger, and a rotation gear and the ball screw nut is formed integrally, and from the injection housing fixing member in said second reduction mechanism forms the casing of the injection unit Become.

Further, the injection molding apparatus according to claim 4 which refers to claim 1, 2 or 3 further comprises a movable mold comprising a fixed mold and a movable mold movable with respect to the fixed mold. When the mold is driven and clamped, a mold clamping unit having a mold clamping drive mechanism for opening and closing the mold is provided, and the mold clamping drive mechanism is another deceleration mechanism (third deceleration mechanism similar to the deceleration mechanism ). And a driven body in the third reduction mechanism is a clamping side engaging body that engages with a ball screw shaft whose tip is connected to a movable mold and rotates the ball screw shaft. a rotation gear side engaging member and in the third of the speed reduction mechanism are integrally formed and consist of clamping housing fixing member in the third reduction mechanism forms the casing of the clamping portion.

A speed reduction mechanism applied to the present invention is a speed reduction mechanism that amplifies rotational power by decelerating the rotational speed of power output from a power generation source and transmits the rotational power to a driven body. A crank that converts power to eccentric rotational power, an eccentric motion gear that transmits the eccentric rotational power from the crank, and a loose-fitting hole is formed in the eccentric gear, and one end is in the loose-fitting hole. The loose fitting is fixed to the fixed member whose other end is fixed, or a loose fitting hole is formed in the fixed member whose position is fixed, and one end is loosely fitted in the loose fitting hole and the other end is eccentric. A pin fixed to the gear, and a restriction pin that regulates the rotation of the eccentric gear while allowing the eccentric motion of the eccentric gear within the range in which the pin moves within the loose fitting hole, and the driven body integrally Formed and disposed on the center side of the eccentric gear, or the eccentric It is arranged so as to include the dynamic gear inside, and partially meshes with the tooth portion in the eccentric direction of the eccentric gear, and the partial mesh position according to the change in the eccentric direction of the eccentric gear since There comprising a rotation gear that rotates the rotational power accepted by by rotating, inexpensive, and able to reduce the power transmission loss to the minimum with a simple configuration, miniaturization of an injection molding device using the same In addition, the price can be reduced and the reliability can be improved.

  Embodiments of the present invention will be described with reference to the drawings. 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 speed reduction mechanism applied to the present invention includes, as will be described later, a crank that converts rotational power from a power generation source into eccentric rotational power, and an eccentric motion gear that transmits the eccentric rotational power from the crank. A loose fitting hole is formed in the eccentric gear, and one end is loosely fitted in the loose fitting hole and the other end is fixed to a fixed member fixed in position, or is loosely fitted in a fixed member fixed in position. Eccentric motion of the eccentric gear in the range where the hole is formed, one end is loosely fitted in the loose fitting hole and the other end is fixed to the eccentric gear, and the pin moves in the loose fitting hole A regulation pin that regulates the rotation of the eccentric gear while allowing the rotation, and a driven body, and is disposed on the center side of the eccentric gear and includes the eccentric gear inside. And is partially meshed with the tooth portion in the eccentric direction in the eccentric gear. Both have a rotation gear that rotates the rotational power accepted by by partial meshing position in response to changes in the direction of eccentricity of the eccentric motion gear rotates the main configuration.

  In the injection molding apparatus, the speed reducer mechanism is used for a scroll driving mechanism, a plunger driving mechanism, and a mold clamping driving mechanism. At this time, similar members (crank, restriction pin, eccentric motion gear, rotation gear, etc.) in the scroll drive mechanism, the plunger drive mechanism, and the mold clamping drive mechanism are distinguished as first to third, respectively. For example, a crank in the scroll driving mechanism is described as a first crank, a crank in the plunger driving mechanism is described as a second crank, and a crank in the mold clamping driving mechanism is described as a third crank. The power generation source corresponds to a scroll motor, an injection motor, and a mold clamping motor.

Incidentally, the application of the reduction mechanism is not limited to the injection molding apparatus, free gear as the requirement that it is formed integrally with the driven member, reduction drive system, etc. of the reduction drive system and electrical equipment of the motor vehicle It is added that it can be applied to general speed reduction equipment.

  FIG. 1 is a cross-sectional view of such an injection molding apparatus. The injection molding apparatus includes a movable mold 401 and a fixed mold 402, and a cavity K, which is a space into which plasticized material is injected on the abutting surfaces. Mold 40 to be formed, plasticizing part 10 for heating and plasticizing the material and kneading the material, and injection for injecting the plasticized material in injection cylinder 201 into cavity K The mold clamping part 30 which opens and closes the part 20 and the mold 40 is the main component.

  FIG. 2 is an exploded perspective view showing a main part of the plasticizing part 10, which has a plasticizing housing 101 and a fixed die plate 102, and the plasticizing housing 101 has a material charging hole 103 into which a material such as pellets is charged. Is formed.

  In the plasticizing housing 101 and the fixed die plate 102, a barrel 104 for heating the material charged from the material charging hole 103 and a spiral groove 105 for conveying the material are formed and rotated while contacting the barrel 104. A material in the spiral groove 105 is conveyed, stirred, plasticized, kneaded, and after plasticization, a scroll 106 is pumped in the direction of the rotation center axis with a Weisenberg effect, and a scroll driving mechanism 107 that rotationally drives the scroll 106. A check valve mechanism 108 is provided for controlling injection and backflow of the plasticized material.

  As shown in FIG. 3, the scroll 106 is a rotating body having a substantially short cylindrical shape, and a spiral groove 105 is formed on the side of the rotating body that contacts the fixed die plate 102. The spiral groove 105 is formed in a plurality of strips (in the case of one strip in FIG. 2) so that the scroll shaft hole 109 formed in the rotation shaft contracts in accordance with the rotation direction of the scroll 106, and the back surface thereof is a recess 116. The first rotation gear 110 is formed on the inner surface of the recess 116. A check valve 121 is mounted in the scroll shaft hole 109.

Hereinafter, the surface where the scroll 106 contacts the barrel 104 is referred to as a scroll action surface 111, and the side surface thereof is referred to as a scroll side surface 112. Further, the spiral groove 105 formed on the scroll working surface 111 is referred to as a feeding groove 113, and the spiral groove 105 formed on the scroll side surface 112 is referred to as a scraping groove 114. Accordingly, the spiral groove 105 is constituted by the scraping groove 114 and the feeding groove 113.
The scroll action surface 111 is formed to have a concave conical shape close to a plane having an apex angle θ of θ = 176 ° to 174 ° to generate a direct pressure (N), thereby enabling the material to be pumped. . Of course, it is good also as the convex cone shape of the same angle.

The barrel 104 is provided with a plurality of heaters (not shown) for heating the material inside, and the surface on the scroll 106 side is formed in a shape in close contact with the scroll action surface 111, and is plasticized on the central axis thereof A flow path 115 is formed.
In addition, a cooling water channel 117 that forms a flow path of the cooling water is formed so that the plasticizing housing 101 and the fixed die plate 102 and various members included therein are not heated by the heat of the barrel 104, and the heat insulating material. 118 is provided as appropriate.

  The scroll 106 is rotatably disposed in the plasticizing housing 101 via a bearing A, and a scroll driving mechanism 107 that reduces the rotation speed of the scroll motor 120 and transmits it to the scroll 106 is provided.

  The scroll drive mechanism 107 has an annular first eccentric motion in which teeth that mesh with the first rotation gear 110 are formed on the outer peripheral surface and a plurality of first restriction pin fixing holes 123 are inserted in the thickness direction. A gear 124, a first restriction pin 130 that is inserted into the first restriction pin fixing hole 123, and a sleeve-shaped first crank 125 that transmits rotational power to the first eccentric movement gear 124, are scrolled to the first crank 125. A motor shaft 126 of the motor 120 is mounted.

  The first crank 125 is composed of a cylindrical portion 128 into which the motor shaft 126 is inserted, and a crank portion 129 that is eccentric with respect to the cylindrical portion 128. One eccentric motion gear 124 is inserted, and a bearing B is externally inserted into the cylindrical portion 128 so as to be inserted into the plasticizing housing 101.

The plasticized housing 101 is fixed to the fixed die plate 102, and the flange 132 is screwed to the plasticized housing 101.
The flange 132 is provided with a first loose-fitting hole 133 in which the head 131 of the first restriction pin 130 is loosely fitted and the movement of the first eccentric movement gear 124 is restricted.

  With such a configuration, the rotational motion of the motor shaft 126 is transmitted to the first crank 125, the crank portion 129 performs eccentric rotational motion, and this eccentric rotational motion is the first eccentric motion gear via the bearing C. 124.

  FIG. 4 is a schematic diagram for explaining such a speed reduction mechanism. When the first eccentric movement gear 124 is eccentric by the first crank 125, the tooth portion of the first eccentric movement gear 124 in the eccentric direction and the first eccentric movement gear 124 are shown. The tooth part of 1 rotation gear 110 will be in part meshing, and the teeth of other parts will be in the separated state.

When rotating in the eccentric direction in such a state, the head of the first restriction pin 130 moves along the inner peripheral surface of the first loose-fitting hole 133 to move the first eccentric movement gear 124 and the first rotation gear 110. The part that meshes with this rotates. Since the rotation of the first eccentric movement gear 124 is restricted by the first restriction pin 130, the change in the meshing position is allowed by the rotation of the first rotation gear 110, and the rotational power of the scroll motor 120 is the first. It is transmitted to the first rotation gear 110 at a reduction ratio determined by the first rotation gear 110 and the first eccentric movement gear 124.

In the speed reduction mechanism including the first rotation gear 110, the first eccentric movement gear 124, and the first restriction pin 130 that restricts the movement of the first eccentric movement gear 124, the teeth of the first rotation gear 110 and the first eccentric gear The teeth of the movement gear 124 are both parallel teeth, and there is almost no sliding between the teeth as in the worm gear and the worm wheel, so the tooth wear loss can be reduced and the power loss associated with the sliding is greatly increased. It becomes possible to suppress.
Further, since the movable part is configured to contact other members via the bearings A to C, the power transmission loss in the movable part can be greatly reduced.

  The check valve mechanism 108 controls whether or not the plasticized material is delivered from the scroll 106 to the injection unit 20, and the material injected toward the cavity K by the injection unit 20 flows back to the plasticization unit 10. As shown in FIG. 5, it comprises a check valve 121, a valve screw 135, a one-way clutch 136, a valve screw storage 151, and the like.

  The end of the check valve 121 on the barrel 104 side abuts on a conical valve pocket 139 that is an opening of a flow path 115 that forms a flow path of the material that flows through the barrel 104, and the valve pocket 139 is The open / close end 140 is formed in a closed shape, and the other end of the check valve 121 is formed with a threaded screw 141, and a rotation stop 142 is formed in the middle of these. The border between the rotation stop portion 142 and the screw portion 141 is a contact portion 152 that forms a step.

  The rotation stop portion 142 is formed by cutting the check valve 121 into, for example, a D shape, and a hole (rotation stop hole) 144 having the same shape as the cross-sectional shape of the rotation stop portion 142 is formed in the scroll shaft hole 109. . The rotation stop portion 142 of the check valve 121 is inserted into the rotation stop hole 144 so that the free rotation of the check valve 121 is restricted and the check valve 121 can advance and retreat in the axial direction.

  The valve screw 135 includes a clutch insertion tube portion 145 into which the one-way clutch 136 is inserted and a taper portion 146 formed so that the vicinity of one end thereof is reduced toward the motor shaft 126. A female screw portion 147 to which the portion 141 is screwed is formed.

  On the other hand, the motor shaft 126 is formed with a valve screw storage portion 151 including a clutch storage hole 137 for storing the one-way clutch 136 and a tapered portion storage hole 150 for storing the tapered portion 146.

  Then, as shown in FIG. 6A, the motor shaft 126 rotates in a predetermined direction (a direction in which the plasticized material is injected). In this state, the taper portion 146 of the valve screw 135 is press-fitted into the taper portion accommodation hole 150 of the valve screw housing portion 151, and the one-way clutch 136 is in a free state. Therefore, when the motor shaft 126 rotates, the taper portion housing is accommodated. The valve screw 135 is rotated by friction between the hole 150 and the taper portion 146 of the valve screw 135, and the check valve 121 moves toward the motor shaft 126 side by screwing the screw portion 141 and the female screw portion 147.

  As a result, the open / close end 140 of the check valve 121 is separated from the valve pocket 139, the valve pocket 139 is opened, and the material is sent into the injection cylinder 201 through the flow path 115 as shown in FIG. The In FIG. 6, a solid line arrow L1 indicates the direction in which the check valve moves, and a solid line arrow L2 indicates the direction in which the plunger 202 moves. A dotted arrow L3 indicates the material flow.

  When the contact portion 152 of the check valve 121 contacts the contact portion 153 of the scroll shaft hole 109, the movement of the check valve 121 is regulated by this contact, and the valve screw 135 is attracted to the check valve 121. As shown in the enlarged view of FIG. 6B, a minute gap δ is generated between the tapered portion 146 and the tapered portion receiving hole 150, and the press-fitted state is released. This gap is a gap that allows the tapered portion 146 and the tapered portion accommodation hole 150 to be idle.

  When the taper portion 146 and the taper portion accommodation hole 150 are idle, the rotational driving force to the check valve 121 is not transmitted, so that the scroll 106 can continue to rotate and continue to inject material.

  When a predetermined amount of material is fed into the injection cylinder 201, the scroll motor 120 is reversely rotated as shown in FIG. Since the rotation direction is a direction in which the one-way clutch 136 functions as a clutch state, the rotation of the motor shaft 126 is transmitted to the valve screw 135 via the one-way clutch 136, and the check valve 121 moves toward the valve pocket 139 and opens and closes the end portion. 140 abuts against the valve pocket 139 to close the opening.

  When the open / close end 140 abuts the valve pocket 139, the check valve 121 cannot move any further, so that the valve screw 135 moves to the motor shaft 126 side, and the taper portion 146 is pushed into the taper portion accommodation hole 150, and FIG. ), And returns to the state shown in FIG.

  In a state where the valve pocket 139 is closed, even if the plunger 202 injects the material in the injection cylinder 201, the material does not flow back to the scroll 106 side due to the injection pressure.

  Thus, since the check valve 121 can be reliably operated with a simple configuration using inexpensive parts, the reliability is improved and the check valve 121 moves like a piston in the scroll shaft hole 109. Therefore, when the injection molding apparatus is started, the problem that the material enters the gap or the like during the previous operation and the movement of the check valve 121 becomes worse is solved.

  Further, since the drive source of the check valve 121 is the scroll motor 120 that drives the scroll 106, it is possible to reduce the cost by downsizing the injection molding apparatus and reducing the number of parts by using the power source together.

  As shown in detail in FIG. 7, the injection unit 20 is provided in the above-described injection cylinder 201, the plunger 202 attached to the injection cylinder 201, the plunger drive mechanism 203 that drives the plunger 202, and the fixed die plate 102. And a runner tube 204 for injecting the material from the injection cylinder 201 into the cavity K.

The plunger drive mechanism 203 is provided in the injection housing 211 with the second pulley 207, the second eccentric motion gear 208, the second rotation gear 209, and the second ball screw shaft 213 to which the power of the injection motor 206 is transmitted as the main components. It has been.
The tip of the second ball screw shaft 213 is a plunger 202 that forms the piston of the injection cylinder 201, and the rear end of the second ball screw shaft 213 has an asymmetric cross section (for example, D shape) with respect to the axis.

  The second pulley 207 is sandwiched by a pair of bearings D and rotates freely. A through hole 215 into which the head 217 of the second ball screw shaft 213 is inserted is formed inside. The inner peripheral surface of the end of the second pulley 207 on the second ball screw shaft 213 side is formed as a cylindrical surface coaxial with the rotational axis of the second pulley 207, and the outer peripheral surface is a cylinder that is eccentric with respect to the rotational axis. A second crank 216 comprising a surface is formed. Note that a bearing E is extrapolated to the second crank 216.

The injection housing 211 is provided with a second ball screw shaft insertion hole 219 and a nut engaging portion 220, and a plurality of second loose fitting holes 222 are provided on the end surface on the injection motor 206 side (second pulley 207 side). .
When the second ball screw nut 214 is mounted and stored in the nut engaging portion 220, the second ball screw nut 214 is fixed to the injection housing 211 with a screw (not shown).

  The second eccentric movement gear 208 is an annular gear having teeth formed on the inner peripheral surface and a plurality of second restricting pin fixing holes 223 formed in the thickness direction, and the second crank 216 via the bearing E. It is attached to.

  Further, the second rotation gear 209 has teeth formed on the outer peripheral surface and a second ball screw shaft engaging portion 225 through which the head 217 of the second ball screw shaft 213 is inserted and engaged at the center. A bearing F is extrapolated to the outer peripheral portion of the two-ball screw shaft engaging portion 225 and is inserted into the second eccentric movement gear 208.

  Then, when the second pulley 207 rotates, the second crank 216 performs an eccentric rotational motion, and the eccentric rotational motion is transmitted to the second eccentric motion gear 208. A second regulating pin 230 is fixed to the second eccentric movement gear 208, and its head is loosely fitted in a second loose fitting hole 222 provided in the injection housing 211. Since the head of the second restriction pin 230 moves eccentrically within a range in which it can move in the second loose-fitting hole 222, the second rotation gear 209 partially meshes while the rotation motion is restricted, and this meshing portion is By rotating, the second rotation gear 209 rotates.

  When the second rotation gear 209 rotates, the rotation is transmitted to the second ball screw shaft 213 by the engagement between the second ball screw shaft engaging portion 225 and the head 217 of the second ball screw shaft 213, and the second rotation gear 209 is rotated. When rotating in a certain direction, the plunger 202 moves so as to be extracted from the injection cylinder 201 and the inside of the injection cylinder 201 becomes empty, and when rotated in the opposite direction, the cylinder contents (material) of the injection cylinder 201 are pushed out.

  As shown in detail in FIG. 8, the mold clamping unit 30 includes a mold clamping housing 301, a movable die plate 302, and a mold clamping drive mechanism 303. The mold clamping housing 301 is connected to the fixed die plate 102 by a plurality of divers 304. The movable die plate 302 is inserted into the diver 304 and can be advanced and retracted by the mold clamping drive mechanism 303.

  The mold clamping drive mechanism 303 includes a third ball screw shaft 311, a mold clamping motor 312, a third pulley 314, a third restriction pin 315, a third eccentric movement gear 322, a third rotation gear 317, and the like. The end of the third ball screw shaft 311 on the third pulley 314 side is a head 326 having a cross section that is asymmetric (eg, D-shaped) with respect to the shaft center, and a female screw 313 is formed at the center thereof. Yes.

  The third pulley 314 is sandwiched by a pair of bearings I and is rotated by the rotational power of the mold clamping motor 312, and a third crank 327 is provided at the tip thereof. One end of the third crank 327 is formed with a cylindrical hole 316 that is coaxial with the rotation shaft of the third pulley 314, and the outer peripheral surface of the third crank 327 has a cylindrical shape composed of a circumferential surface eccentric to the rotation shaft. H is extrapolated. The cylindrical hole 316 is a hole for accommodating the head of the fixing bolt 323.

  The third crank 327 is housed in the housing portion 318 provided in the mold clamping housing 301 via the bearing I. The mold clamping housing 301 is formed with an insertion hole 324 through which the head 326 of the third ball screw shaft 311 is inserted and a third ball screw shaft 311 side surface on which the head of the third restriction pin 315 is loosely fitted. A plurality of loose fitting holes 325 are provided.

  The third eccentric gear 322 is an annular member in which teeth are formed on the outer peripheral surface and a plurality of third restricting pin fixing holes 321 are formed in the thickness direction. A crank 327 is inserted.

In the third rotation gear 317, teeth are formed on the inner peripheral surface of a member protruding from the surface on the third eccentric movement gear 322 side, and the head of the third ball screw shaft 311 is inserted on the other surface. An engagement hole 319 to be engaged is provided.
A bolt hole 320 through which the fixing bolt 323 is inserted is formed at the center of the third rotation gear 317. A head 326 of the third ball screw shaft 311 is attached to the engagement hole 319 and tightened with the fixing bolt 323. Thus, the third rotation gear 317 and the third ball screw shaft 311 are connected.

  The rotational power of the mold clamping motor 312 is transmitted as an eccentric rotational motion of the third crank 327 via the third pulley 314. This eccentric rotational movement is transmitted to the third eccentric movement gear 322 via the bearing H, and the teeth of the third rotation gear 317 and a part of the third rotation gear 317 according to the movement restriction of the third restriction pin 315 by the third loose fitting hole 325. Since the meshing position rotates in accordance with the eccentric direction, the third rotation gear 317 rotates, and accordingly, the third ball screw shaft 311 rotates.

The mold 40 is a cassette mold 40 composed of a movable mold 401 attached to the movable die plate 302 and a fixed mold 402 attached to the fixed die plate 102, and one of the molds 40 has a plurality of positions. A fixing pin 403 is provided, and a regulating pin receiving hole 404 into which the positioning pin 403 is fitted is provided in the opposite mold 40.
Furthermore, a runner receiving hole 406 into which the hot runner 405 is inserted is formed in the fixed mold 402 attached to the fixed die plate 102.

  The movable mold 401 is provided with a molded product extrusion mechanism 407. This molded product extrusion mechanism 407 is fixed to a support plate 409 to which a plurality of extrusion pins 408 provided so as to pass through the movable die 401 and to be inserted into the cavity K are fixed, and to the movable plate 409. A support rod 410 to be inserted into 401, a spring 411 that is inserted into the support rod 410 and biases the support plate 409 so that the head of the push pin 408 forms the wall surface of the cavity K at normal times, and the support plate 409 are fixed. And a thrust bearing 413 attached to the extrusion plate 412.

  Then, when the molded product push-out mechanism 407 takes out the injection-molded product, the third ball screw shaft 311 comes into contact with the thrust bearing 413 when the movable die plate 302 is moved backward toward the mold clamping housing 301 by a predetermined amount or more. Then, the support plate 409 is pushed toward the cavity K against the spring 411. Thereby, the injection molded product in the cavity K can be easily extruded by the extrusion pin 408.

  The thrust bearing 413 is provided so that the head of the third ball screw shaft 311 does not damage the push plate 412 and may be a thrust sliding bearing or the like.

In addition, the ball screw nut and the rotating gear in the injection unit 20 and the mold clamping unit 30 have separate structures. However, the present invention is not limited to this. For example, the ball screw nut of the reduction mechanism in the injection unit 20 and die clamping unit 30 and the rotation gear may be formed integrally as shown in FIGS. 9 and 10.
9 shows the case in the injection part 20, and FIG. 10 shows the case in the mold clamping part 30.
As a result, since the two members become the one member, the cost can be reduced and the device can be further downsized.

Further, the first restriction pin 130 to the third restriction pin 315 described so far are fixed to the first eccentric movement gear 124 to the third eccentric movement gear 322, and the first loose fitting provided in the plasticizing housing 101 or the like. Although it was the structure loosely fitted in the hole 133-the 3rd loose fitting hole 325, the reverse structure may be sufficient.
That is, the function of the first restricting pin 130 and the like is to perform the position restriction of the first eccentric movement gear 124 and the like with respect to the plasticizing housing 101 and the like which are fixing members. A restriction pin fixing hole 123 is formed to fix the first restriction pin 130 or the like, and a first loose fitting hole 133 or the like is formed in the first eccentric movement gear 124 or the like to loosely fit the first restriction pin 130 or the like. Will be able to carry out similar regulations.

Further, the regulation pin not only loosely fits or fits on a fixing member such as a plasticized housing, but also loosely fits or fits on a driven body 330 that rotates with an eccentric motion gear as shown in FIG. It may be a configuration.
In this case, the rotating gear described so far is fixed. The meshing relationship between the gear (fixed gear 331) and the third eccentric gear 322 does not change, and the third regulating pin 315 is loosely fitted or fitted to the driven body 330 fixed to the third ball screw shaft 311. Therefore, the rotational power is transmitted to the driven body 330 and the third ball screw shaft 311 rotates.

  Further, a bearing may be provided in order to avoid friction caused by the direct contact of the first restricting pins and the like that are loosely fitted in the loose fitting holes.

  Further, in the description so far, the eccentric gear and the rotation gear have a one-to-one relationship, and one is provided, but a configuration in which a plurality of eccentric gears are provided for one rotation gear. It is also possible to make it.

  For example, as shown in FIG. 12, n first eccentric motion gears 124a to 124c, bearings Ba to Bc, and first cranks 129a to 129c are provided (FIG. 12 shows three cases each). At this time, the first cranks 129 a to 129 c of 3 are shifted by an equal angle with respect to the rotation center of the motor shaft 126. Then, one end of the first restriction pin 130 is loosely fitted in the first loose fitting holes 133a to 133c of the first eccentric movement gears 124a to 124c, and the other end is fixed to the flange 132.

  With such a configuration, the first eccentric movement gears 124a to 124c are eccentric according to the phases of the first cranks 129a to 129c and partially mesh with the first rotation gear 110, respectively. In 110, rotational power is simultaneously transmitted from each of the first eccentric gears 124a to 124c, the power transmission point is axisymmetric, and smooth rotational power can be transmitted, and the same power can be transmitted. Since the power of each of the first eccentric gears 124a to 124c and the first cranks 129a to 129c is divided when transmitting to the one rotation gear 110, wear and the like can be suppressed.

  Further, the present invention is not limited to the inclusion relationship between the eccentric gear and the rotation gear. For example, in FIG. 10, the third eccentric gear 322 has internal teeth and the third rotation gear 317 has external teeth. However, as shown in FIG. 13, the third eccentric gear 322 has external teeth and the third rotation gear. The same effect can be obtained by using 317 as an internal tooth.

  Further, in the above description, the mold clamping unit 30 and the like are configured to transmit the rotational power of the motor to the crank via a pulley, but may be configured to directly attach the crank to the motor shaft like a plasticizing unit.

It is sectional drawing of the injection molding apparatus which concerns on this invention. It is a cross-sectional perspective exploded view of a plasticization part. It is a figure which shows the structure of a scroll. It is a figure applied to description of operation | movement of a deceleration mechanism. It is a cross-sectional perspective exploded view explaining a check valve mechanism. It is a figure applied to description of operation | movement of a check valve mechanism. It is a cross-sectional perspective exploded view of an injection part. It is a section perspective exploded view of a mold clamping part. It is a figure at the time of integrally forming the ball screw nut and rotation gear of the speed-reduction mechanism in an injection part. It is a figure at the time of integrally forming the ball screw nut and rotation gear of the speed-reduction mechanism in a mold clamping part. It is a figure which shows the example in the case of carrying out loose fitting or fitting to a to-be-driven body, without making a regulation pin loosely fitting or fitting to fixing members, such as a plasticization housing. It is a figure showing an example at the time of using a plurality of eccentric motion gears. It is a figure which shows the inclusion relationship of the tooth | gear in an eccentric gear and a rotation gear.

Explanation of symbols

A to I Bearing 10 Plasticizing section 20 Injection section 30 Mold clamping section 40 Cassette mold 101 Plasticizing housing 102 Fixed die plate 104 Barrel 105 Spiral groove 106 Scroll 107 Scroll drive mechanism 108 Check valve mechanism 109 Scroll shaft hole 110 First rotation Gear 111 Scroll action surface 112 Scroll side 113 Feed groove 114 Scratch groove 120 Scroll motor 121 Check valve 123 First restriction pin fixing hole 124 (124a to 124c) First eccentric motion gear 125 (129a to 125c) First crank 126 Motor shaft 128 Cylinder portion 129 Crank portion 130 First restriction pin 131 Head portion 132 Flange 133 (133a to 133c) First loose fitting hole 135 Valve receiving member 136 One-way clutch 137 Cladding Insertion portion 139 Valve pocket 140 Open / close end portion 141 Engagement portion 142 Rotation stop portion 144 Rotation stop hole 145 Clutch fitting portion 146 Taper portion 147 Engagement portion 150 Taper fitting portion 151 Receiving member insertion portion 152, 153 Step Part 201 Injection cylinder 202 Plunger 203 Plunger drive mechanism 204 Runner tube 206 Injection motor 207 Second pulley 208 Second eccentric gear 209 Second rotation gear 210 Second ball screw shaft 211 Injection housing 213 Second ball screw shaft 214 Second ball screw nut 215 Through-hole 216 Second crank 217 Head 219 Second ball screw shaft insertion hole 220 Nut engagement portion 222 Second loose fitting hole 223 Second restriction pin fixing hole 225 Second ball screw shaft engagement portion 230 Second restriction pin 301 type Tightening housing 30 Movable die plate 303 Mold clamping drive mechanism 304 Diver 311 Third ball screw shaft 312 Mold clamping motor 313 Female screw 314 Third pulley 315 Third restriction pin 316 Cylindrical hole 317 Third rotation gear 318 Storage part 319 Engagement hole 320 Bolt hole 321 Third restriction pin fixing hole 322 Third eccentric motion gear 323 Fixing bolt 324 Insertion hole 325 Third loose fitting hole 326 Head 327 Third crank 328 Third ball screw nut 401 Movable die 402 Fixed die 403 Positioning pin 404 Regulator pin receiving hole

Claims (6)

A speed reduction mechanism that amplifies the rotational power by decelerating the rotational speed of the power output from the power generation source and transmits it to the driven body;
A crank that converts the rotational power from the power generation source into eccentric rotational power;
An eccentric motion gear to which the eccentric rotational power is transmitted from the crank;
A loose fitting hole is formed in the eccentric gear, and one end is loosely fitted in the loose fitting hole and the other end is fixed to a fixed member fixed in position, or a loose fitting hole is formed in the fixed member fixed in position. The pin is formed with one end loosely fitted into the loose fitting hole and the other end fixed to the eccentric movement gear, and the eccentric movement gear is eccentric within a range in which the pin moves within the loose fitting hole. A regulation pin that regulates rotation of the eccentric gear while allowing movement;
Eccentric direction in the eccentric gear is formed integrally with the driven body and is arranged on the center side of the eccentric gear or disposed so as to include the eccentric gear on the inside. And a rotating gear that rotates by receiving rotational power by rotating the partial meshing position according to a change in the eccentric direction of the eccentric gear. To reduce the speed.   The speed reduction mechanism according to claim 1, wherein the driven body is a ball screw, and the rotation gear is formed on a ball screw shaft or a ball screw nut of the ball screw. An injection molding apparatus provided with a plasticizing portion including a scroll driving mechanism for driving the scroll when plasticizing and feeding the material by scroll,
The scroll driving mechanism is provided with the speed reduction mechanism, and the driven body is a scroll for pressure-feeding the material in the spiral groove that shrinks toward the rotation center axis toward the rotation center axis, and the fixed 2. An injection molding apparatus using a speed reduction mechanism according to claim 1, wherein the member is a plasticizing housing forming a casing of the plasticizing portion. An injection molding apparatus having an injection part having a plunger drive mechanism for driving a plunger when a plasticized material in the injection cylinder is injected into a cavity of an extrusion mold by a plunger that forms a piston of the injection cylinder. And
The plunger drive mechanism includes the speed reduction mechanism, and at that time, the driven body engages with a ball screw shaft whose tip portion forms the plunger, and advances and retreats in the axial direction while restricting free rotation of the ball screw shaft. 3. The injection-side engagement member that enables the injection-side engagement member and the rotation gear to be integrally formed, and the fixing member is an injection housing that forms a casing of an injection portion. Injection molding device using a speed reduction mechanism. An injection molding apparatus having an injection part having a plunger drive mechanism for driving a plunger when a plasticized material in the injection cylinder is injected into a cavity of an extrusion mold by a plunger that forms a piston of the injection cylinder. And
The plunger drive mechanism includes the speed reduction mechanism, and at this time, the driven body is a ball screw nut whose tip is screwed to a ball screw shaft forming the plunger, and the ball screw nut and the rotation gear are integrally formed. 3. The injection molding apparatus using a speed reduction mechanism according to claim 2, wherein the fixing member is an injection housing forming a casing of an injection portion. A mold having a mold clamping drive mechanism for opening and closing the mold when the mold is composed of a fixed mold and a movable mold movable relative to the fixed mold. An injection molding apparatus provided with a fastening part,
The mold clamping drive mechanism includes the speed reduction mechanism, and at this time, the driven body engages with a ball screw shaft whose tip is connected to the movable mold to rotate the ball screw shaft. 2. The reduction mechanism according to claim 1, wherein the mold clamping side engaging body and the rotation gear are integrally formed, and the fixing member is a mold clamping housing forming a casing of the mold clamping portion. Injection molding equipment.

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