Material supply device and injection molding device

Abstract

To provide a technique capable of suppressing an influence on a flow of a plasticized material while suppressing a backflow of the plasticized material from a nozzle side to a screw side.SOLUTION: The material supply device includes a drive motor, a screw that has a groove forming surface in which a groove is formed and is rotated by the drive motor, a barrel that has a facing surface facing the groove forming surface and in which a communication hole through which a plasticized material flows is formed, a nozzle that communicates with the communication hole and injects the plasticized material to the outside, and a valve portion provided in the screw. The valve portion is configured to be capable of performing an advancing operation of moving in a first direction from the screw toward the communication hole and a retreating operation of moving in a second direction opposite to the first direction. The valve portion is configured to open and close the communication hole by a forward movement and a backward movement.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a material supply device and an injection molding device. [Background technology]

[0002] Patent Document 1 discloses a material supply device that includes a screw provided in a plasticizing device that produces a plasticized material, a nozzle that injects the plasticized material to the outside, and a check valve. The check valve prevents the plasticized material from flowing back from the nozzle side to the screw side. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-32159 Summary of the Invention [Problem to be solved by the invention]

[0004] The check valve may affect the flow of plasticized material in the material supply device. [Means for solving the problem]

[0005] According to a first aspect of the present disclosure, there is provided a material supplying device. The material supplying device includes a drive motor, a screw having a grooved surface with grooves formed therein and rotated by the drive motor, a barrel having an opposing surface facing the grooved surface and formed with a communication hole through which a plasticized material flows, a nozzle communicating with the communication hole and injecting the plasticized material to the outside, and a valve unit provided on the screw. The valve unit is configured to be able to move forward in a first direction from the screw toward the communication hole and to move backward in a second direction opposite to the first direction, and the valve unit is configured to open and close the communication hole by the forward movement and the backward movement.

[0006] According to a second aspect of the present disclosure, there is provided an injection molding apparatus including the material supply device of the above aspect and a mold clamping device that opens and closes a mold into which the plasticized material is injected from the nozzle. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a top view showing a schematic configuration of an injection molding apparatus according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a schematic configuration of a material supply device. [Figure 3] FIG. 2 is a perspective view showing a schematic configuration of a flat screw. [Figure 4] FIG. 2 is a schematic plan view of the barrel. [Figure 5] FIG. 10 is a first diagram illustrating the operation of the valve portion. [Figure 6] FIG. 10 is a second diagram illustrating the operation of the valve portion. [Figure 7] 10 is a flowchart of a molding process. [Figure 8] FIG. 10 is a cross-sectional view showing a schematic configuration of a valve portion in a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] A. First embodiment: FIG. 1 is a top view showing a schematic configuration of an injection molding apparatus 10 in a first embodiment. FIG. 1 shows arrows indicating mutually orthogonal X, Y, and Z directions. The X and Y directions are parallel to a horizontal plane, and the Z direction is opposite to the direction of gravity. The X, Y, and Z directions shown in FIG. 2 and subsequent figures correspond to the X, Y, and Z directions shown in FIGS. 1 and 2. In the following description, when specifying a direction, positive and negative signs are used in combination to indicate the direction indicated by the arrow, with "+" indicating the positive direction and "-" indicating the negative direction opposite to the direction indicated by the arrow.

[0009] The injection molding apparatus 10 comprises a material supplying apparatus 100, a mold clamping apparatus 130, and a control unit 500. The injection molding apparatus 10 injects plasticized material produced by the material supplying apparatus 100 into a molding die 160 to form a molded product. The operation of the material supplying apparatus 100 and the mold clamping apparatus 130 is controlled by the control unit 500. The control unit 500 is configured as a computer equipped with a CPU and memory, and controls each part of the injection molding apparatus 10 by the CPU executing a program stored in the memory. Note that the control unit 500 may also be configured as a circuit.

[0010] A metal forming die 160 is attached to the mold clamping device 130. The forming die 160 is not limited to being made of metal, and may be made of resin or ceramic. The metal forming die 160 is called a mold. The forming die 160 includes a fixed die 161 and a movable die 162. The fixed die 161 is a die that is fixed relative to the material supply device 100. The movable die 162 is a die that can be moved forward and backward in the mold clamping direction relative to the fixed die 161 by the mold clamping device 130. In this embodiment, the mold clamping direction is the -Y direction.

[0011] The mold clamping device 130 has the function of opening and closing the fixed mold 161 and the movable mold 162. Under the control of the control unit 500, the mold clamping device 130 drives the mold drive unit 131 formed by a motor to rotate the ball screw 132, and moves the movable mold 162 connected to the ball screw 132 relative to the fixed mold 161, thereby opening and closing the casting mold 160.

[0012] A hopper 30 into which the material for the molded product is fed is connected to the material supply device 100. For example, a thermoplastic resin formed into pellets is used as the material for the molded product. Examples of the thermoplastic resin that can be used include ABS (acrylonitrile butadiene styrene), PC (polycarbonate), POM (polyacetal), PP (polypropylene), and PBT (polybutylene terephthalate). The material for the molded product may contain metal or ceramic in addition to the thermoplastic resin. The material may be supplied to the material supply device 100 not only through the hopper 30 but also through a tube through which the material is pressure-fed, for example.

[0013] The material supply device 100 plasticizes at least a portion of the material supplied from the hopper 30 to produce a plasticized material, and then injects the produced plasticized material into a cavity defined between the fixed mold 161 and the movable mold 162. In this specification, "plasticization" is a concept that includes melting, and refers to changing a material from a solid to a fluid state. Specifically, for a material that undergoes glass transition, plasticization refers to raising the temperature of the material to or above the glass transition point. For a material that does not undergo glass transition, plasticization refers to raising the temperature of the material to or above the melting point.

[0014] 2 is a cross-sectional view showing a schematic configuration of material supplying apparatus 100. Material supplying apparatus 100 includes a plasticizing unit 110 that plasticizes at least a portion of a material to produce a plasticized material, a nozzle 114 that injects the plasticized material to the outside, and an injecting unit 120 that communicates with nozzle 114.

[0015] The plasticizing section 110 includes a flat screw 111 , a barrel 112 , a heater 113 , a drive motor 118 , a valve section 170 , and a valve section motor 181 .

[0016] The flat screw 111 is accommodated in the accommodation portion 101. The flat screw 111 is also called a rotor or simply a screw. The flat screw 111 is rotated in the accommodation portion 101 by a drive motor 118. A central axis RX, which is the center of rotation of the flat screw 111, is aligned with the Y direction. A drive shaft 119 of the drive motor 118 is also aligned with the Y direction. In this embodiment, the central axis RX and the drive shaft 119 are arranged at positions offset from each other on the XZ plane. The drive motor 118 is controlled by a control portion 500, and thereby the rotation of the flat screw 111 is controlled by the control portion 500.

[0017] In this embodiment, the driving force of the drive motor 118 is transmitted to the flat screw 111 via a transmission mechanism 140. The transmission mechanism 140 is configured as a belt mechanism that transmits power using a pulley and a belt. The transmission mechanism 140 has a first pulley 141, a second pulley 142, and a transmission belt 143. The first pulley 141 is connected to the drive shaft 119. The second pulley 142 is connected to the flat screw 111. The transmission belt 143 is wound around the first pulley 141 and the second pulley 142. The rotational driving force of the drive motor 118 is transmitted to the second pulley 142 via the first pulley 141 and the transmission belt 143, causing the second pulley 142 to rotate. As a result, the flat screw 111 connected to the second pulley 142 rotates. The transmission mechanism 140 may include a reducer such as a cycloid reducer for reducing the rotational speed of the drive motor 118 and transmitting the reduced rotational speed to the flat screw 111 .

[0018] A communication hole 115 is formed in the center of the barrel 112. The communication hole 115, together with a cylinder 121 described below, constitutes at least a part of a flow path 116 for the plasticizing material. A nozzle 114 is connected to the flow path 116. The nozzle 114 is arranged so that the flow path within the nozzle 114 is aligned along the Y direction.

[0019] The heater 113 heats the barrel 112. The heater 113 functions as a heating unit that heats the material for plasticization. Heating by the heater 113 is controlled by the control unit 500. In FIG. 2, the heater 113 is arranged on the −Y direction side of the cylinder 121, but the heater 113 may also be arranged on the +Z direction side or −Z direction side of the cylinder 121. Furthermore, multiple heaters 113 may be arranged to sandwich the cylinder 121 from the +Z direction side and the −Z direction side.

[0020] FIG. 3 is a perspective view showing a schematic configuration of the flat screw 111. The flat screw 111 has a generally cylindrical shape whose length along the central axis RX is shorter than its length perpendicular to the central axis RX. A spiral groove 202 is formed around a central portion 205 on a groove-forming surface 201 of the flat screw 111 facing the barrel 112. The groove 202 communicates with a material inlet 203 formed on the side surface of the flat screw 111. Material supplied from the hopper 30 is supplied to the groove 202 through the material inlet 203. The grooves 202 are formed by being separated by ridge portions 204. FIG. 3 shows an example in which three grooves 202 are formed, but the number of grooves 202 may be one or more. The groove 202 is not limited to a spiral shape, but may also be a spiral shape or an involute curve shape, or may have a shape extending in an arc from the central portion 205 to the outer periphery.

[0021] 4 is a schematic plan view of the barrel 112. The barrel 112 has an opposing surface 212 that faces the groove forming surface 201 of the flat screw 111. A communicating hole 115 is formed in the center of the opposing surface 212. The opposing surface 212 is formed with a plurality of guide grooves 211 that are connected to the communicating hole 115 and extend spirally from the communicating hole 115 toward the outer periphery. Note that the guide grooves 211 do not necessarily have to be provided in the barrel 112. Furthermore, the guide grooves 211 do not necessarily have to be connected to the communicating hole 115.

[0022] The material supplied to the groove 202 of the flat screw 111 is plasticized between the flat screw 111 and the barrel 112 by the rotation of the flat screw 111 and the heating of the heater 113, and flows along the groove 202 and the guide groove 211 by the rotation of the flat screw 111, and is guided to the center portion 205 of the flat screw 111. The material that has flowed into the center portion 205 is sent to the flow path 116 via a communication hole 115 provided in the center of the barrel 112.

[0023] When plasticizing the material, the control unit 500 controls the drive motor 118 so that the flat screw 111 rotates in a predetermined rotation direction. The "predetermined rotation direction" is the direction, either clockwise or counterclockwise, that is more suitable for guiding the material supplied to the groove 202 to the center portion 205, and is determined by the shape of the groove 202.

[0024] As shown in FIGS. 2 and 3 , in this embodiment, the flat screw 111 has an opening 206. The opening 206 is provided in a central portion 205. The opening 206 opens toward the barrel 112. The opening 206 extends along the Y direction and opens in the +Y direction. The opening 206 has a circular opening shape. The opening 206 accommodates at least a portion of the valve portion 170. A second screw portion 208 is provided on an inner circumferential surface 207 of the opening 206. The second screw portion 208 screws into a first screw portion 178 of the valve portion 170, which will be described later. The second screw portion 208 is configured as a female screw portion.

[0025] The valve portion 170 is provided on the flat screw 111. In this embodiment, the valve portion 170 has a main body portion 171 and a protrusion portion 230. The main body portion 171 has a substantially cylindrical shape corresponding to the shape of the opening portion 206. The main body portion 171 is disposed so that its axial direction is along the Y direction. Of the outer peripheral surfaces of the valve portion 170, an outer peripheral surface 177 of the main body portion 171 is provided with the above-mentioned first screw portion 178. In this embodiment, the first screw portion 178 is provided over the entire outer peripheral surface 177. The first screw portion 178 is configured as a male screw portion that screws into the second screw portion 208.

[0026] The main body 171 has an end face 172 that faces the barrel 112. In this embodiment, the end face 172 is the end face on the +Y direction side of the main body 171. The surface direction of the end face 172 is along the XZ direction.

[0027] The protrusion 230 is provided on the end surface 172. The protrusion 230 has a generally conical shape that protrudes from the end surface 172 in the +Y direction. The protrusion 230 has a tip 231 and a skirt-shaped bottom 232 located on the -Y direction side of the tip 231. The diameter of the tip 231 is smaller than the opening diameter of the inlet end 115a of the communicating hole 115 shown in FIG. 2, and the diameter of the bottom 232 is larger than the opening diameter of the inlet end 115a. The inlet end 115a is the end of the communicating hole 115 on the flat screw 111 side, i.e., the -Y direction side. The central axis of the protrusion 230 generally coincides with the central axis RX. The protrusion 230 functions as a retention suppression section that suppresses retention of the plasticized material near the center portion 205. More specifically, the protrusions 230 efficiently guide the plasticized material from the central portion 205 to the communication holes 115, and prevent the plasticized material from accumulating near the central portion 205. In other embodiments, the valve portion 170 may not include the protrusions 230.

[0028] The valve portion 170 is configured to be capable of moving forward in a first direction D1 from the flat screw 111 toward the communication hole 115, and moving backward in a second direction D2 opposite to the first direction D1. The first direction D1 is the direction from the flat screw 111 toward the communication hole 115. In this embodiment, the first direction D1 is the +Y direction. The second direction D2 is the -Y direction.

[0029] More specifically, in this embodiment, the valve unit 170 is configured to move in the first direction D1 and the second direction D2 by the first screw portion 178, which is threaded onto the second screw portion 208, rotating relative to the second screw portion 208. The first screw portion 178 rotates by the rotational driving force of the valve unit motor 181. The valve unit motor 181 is disposed on the −Y direction side of the main body 171 and is connected to the main body 171. In this embodiment, the rotation axis of the valve unit motor 181 and the rotation axis AX of the valve unit 170 coincide with the central axis RX. In this embodiment, the valve unit motor 181 is configured to rotate the entire valve unit 170 around the central axis RX by its rotational driving force. When the valve unit 170 moves in the Y direction, the valve unit motor 181 moves in the Y direction together with the valve unit 170. The valve unit motor 181 is controlled by the control unit 500. The valve unit motor 181 and the drive motor 118 are configured to be individually controllable by the control unit 500. In another embodiment, the valve unit 170 and the valve unit motor 181 may be configured such that the position of the valve unit motor 181 is fixed and only the valve unit 170 moves in the Y direction. In this case, for example, the valve unit 170 may be moved in the Y direction while the position of the valve unit motor 181 is fixed, using a transmission mechanism that converts the rotational drive force of the valve unit motor 181 into translational motion and transmits it to the valve unit 170.

[0030] In this embodiment, the thread grooves of the first screw portion 178 and the second screw portion 208 are configured so that when the flat screw 111 rotates in a predetermined rotational direction relative to the valve portion 170 with the first screw portion 178 and the second screw portion 208 engaged with each other, the valve portion 170 moves in the second direction D2 relative to the flat screw 111. Therefore, in this embodiment, the control unit 500 can move the valve portion 170 in the first direction D1 relative to the flat screw 111 by controlling the valve portion motor 181 so that the first screw portion 178 rotates in the same direction as the predetermined rotational direction relative to the flat screw 111. Conversely, the control unit 500 can move the valve portion 170 in the second direction D2 relative to the flat screw 111 by controlling the valve portion motor 181 so that the first screw portion 178 rotates in the opposite direction to the predetermined rotational direction relative to the flat screw 111. In addition, the control unit 500 can fix the Y-direction position of the first screw portion 178 relative to the flat screw 111 while rotating the flat screw 111 by rotating the first screw portion 178 and the flat screw 111 at the same number of rotations in a predetermined rotational direction.

[0031] The valve portion 170 is configured to open and close a communication hole 115 of the barrel 112, which will be described later, by moving forward and backward. The opening and closing of the communication hole 115 by the valve portion 170 will be described in detail later.

[0032] As shown in FIG. 2 , the injection unit 120 includes a cylinder 121 communicating with the communication hole 115 and the nozzle 114, a plunger 122 moving within the cylinder 121, and a plunger driver 123. The cylinder 121 has a generally cylindrical shape. The cylinder 121 is also referred to as a sleeve. The plunger 122 has a generally cylindrical shape. The plunger driver 123 includes a ball screw (not shown) that moves the plunger 122 along the longitudinal direction of the plunger 122, and a motor (not shown) that drives the ball screw. In this embodiment, when the ball screw is driven by the motor of the plunger driver 123, the plunger 122 connected to the ball screw moves forward or backward while rotating around a central axis along the longitudinal direction of the plunger 122. "Forward" refers to the direction in which the plunger 122 approaches the flow path 116. "Rear" refers to the direction in which the plunger 122 moves away from the flow path 116.

[0033] In this embodiment, the control unit 500 functions as an injection control unit that controls the injection unit 120. More specifically, the control unit 500 controls the motor of the plunger driving unit 123.

[0034] In the injection unit 120, the control unit 500 controls the plunger drive unit 123 to perform a suction operation and an injection operation. The suction operation is an operation in which the plunger 122 is moved backward to suck the plasticized material from the flow path 116 into the cylinder 121. The injection operation is an operation in which the plunger 122 is moved forward to send the plasticized material sucked into the cylinder 121 to the nozzle 114 and inject the plasticized material to the outside through the nozzle 114. The control unit 500 controls the injection amount, injection speed, and injection pressure of the plasticized material from the nozzle 114 by adjusting the movement amount and movement speed of the plunger 122 during the suction operation and injection operation.

[0035] FIG. 5 is a first diagram illustrating the operation of the valve unit 170. FIG. 6 is a second diagram illustrating the operation of the valve unit 170. FIG. 5 shows the state of the valve unit 170 during delivery, in which the plasticized material is delivered from the flat screw 111 to the barrel 112. FIG. 6 shows the state of the valve unit 170 during injection, in which the plasticized material in the cylinder 121 is delivered to the outside through the nozzle 114. More specifically, during "delivery," the material is plasticized by the plasticizing unit 110 to generate the plasticized material, and the plasticized material is delivered from the flat screw 111 to the communicating hole 115 of the barrel 112. "During delivery" is also referred to as "during plasticization."

[0036] 5, during delivery, the communication hole 115 is open and not closed by the valve portion 170. More specifically, during delivery, the valve portion 170 is located on the −Y direction side of the barrel 112 and is spaced apart from the barrel 112. As a result, the communication hole 115 is not blocked by the valve portion 170.

[0037] As shown in FIG. 5 , a state in which the communication hole 115 is open, i.e., a state in which the communication hole 115 is not closed by the valve portion 170, is also referred to as an open state. Furthermore, within the open state, a state in which the end surface 172 of the main body portion 171 of the valve portion 170 and the surface of the central portion 205 on the barrel 112 side are flush with each other is also referred to as a reference state. FIGS. 2 , 3 , and 5 each show the state of the flat screw 111 and the valve portion 170 in the reference state. In this embodiment, in the reference state, the tip portion 231 of the protrusion 230 is positioned within the communication hole 115.

[0038] As shown in FIG. 6 , during injection, the communication hole 115 is closed by the valve portion 170. Hereinafter, the state in which the communication hole 115 is closed by the valve portion 170 as shown in FIG. 6 is also referred to as the “closed state.” In this embodiment, in the closed state, the valve portion 170 contacts the barrel 112 so as to block the communication hole 115. This closure of the communication hole 115 by the valve portion 170 is achieved by the valve portion 170 contacting the barrel 112 through forward movement. More specifically, in the closed state in this embodiment, the tip portion 231 of the protrusion 230 penetrates further into the communication hole 115 in the +Y direction than in the open state, and the hem portion 232 of the protrusion 230 contacts the wall portion of the inlet end 115a of the communication hole 115 from the −Y direction. As a result, the communication hole 115 is blocked by the hem portion 232 of the protrusion 230. Conversely, when the valve portion 170 is moved away from the barrel 112 by the retraction operation, the communication hole 115 is opened as shown in FIG.

[0039] In the closed state, the communication hole 115 only needs to be closed to the extent that backflow of the plasticized material from the nozzle 114 side to the flat screw 111 side can be suppressed. Therefore, in other embodiments, the communication hole 115 does not need to be completely blocked by the valve portion 170 in the closed state.

[0040] 7 is a flowchart of the molding process in this embodiment. The molding process is a process for forming a molded product by injecting a plasticized material into the cavity of the molding die 160. The molding process is started by the control unit 500, for example, when a user performs a predetermined operation on an operation unit (not shown) provided in the injection molding apparatus 10.

[0041] In step S10, the control unit 500 starts the metering operation. The metering operation is performed to suck and fill the cylinder 121 with the amount of plasticizing material required to form the molded product. The metering operation is achieved by plasticizing the material using the plasticizing unit 110 and performing a suction operation. During the metering operation, the control unit 500 controls the drive motor 118 and the plunger drive unit 123 so that the volume per unit time of the plasticizing material sucked into the cylinder 121 by the suction operation is equal to the increase in the effective volume of the cylinder 121 per unit time due to the movement of the plunger 122 backward. This makes it possible to more uniformly distribute the amount and pressure of the plasticizing material filled into the plunger 122 by the suction operation, thereby suppressing the occurrence of voids and residual stress in the molded product.

[0042] Furthermore, in the metering operation of this embodiment, the control unit 500 controls the drive motor 118 and the valve unit motor 181 so that the valve unit 170 is located at the reference position. More specifically, in the metering operation, the control unit 500 controls the drive motor 118 and the valve unit motor 181 so that the flat screw 111 and the first screw unit 178 rotate in a predetermined rotation direction and so that the rotation speed of the flat screw 111 and the rotation speed of the first screw unit 178 are the same, with the valve unit 170 located at the reference position.

[0043] In step S20, the control unit 500 stops the metering operation. More specifically, in step S20, the control unit 500 controls the drive motor 118 and the plunger drive unit 123 to stop the rotation of the flat screw 111 and the movement of the plunger 122.

[0044] In step S30, the control unit 500 moves the valve unit 170 forward, thereby causing the valve unit 170 to close the communication hole 115. That is, in this embodiment, when closing the communication hole 115, the control unit 500 controls the valve unit motor 181 so that the valve unit 170 moves in the first direction D1 after stopping the rotation of the flat screw 111. More specifically, in step S30, the control unit 500 continues to rotate the valve unit motor 181 even after stopping the rotation of the flat screw 111 in step S20, thereby moving the valve unit 170 in the first direction D1 and causing the protrusion 230 to block the communication hole 115.

[0045] In step S40, the control unit 500 executes the injection operation. That is, in this embodiment, the control unit 500 executes the injection operation in step S40 after the communication hole 115 is closed by the valve unit 170 in step S30.

[0046] According to the material supply device 100 of the present embodiment described above, the communication hole 115 is opened and closed by the forward and backward movement of the valve unit 170 provided on the flat screw 111 relative to the communication hole 115. Therefore, the communication hole 115 can be opened by the backward movement during delivery, and the communication hole 115 can be closed by the forward movement during injection. As a result, it is possible to prevent the plasticized material from flowing back into the flat screw 111 during injection, and to prevent the valve unit 170 from affecting the flow of the plasticized material during delivery.

[0047] More specifically, in other embodiments where a check valve is provided in the flow path 116 to prevent backflow from the nozzle 114 to the flat screw 111, unlike the present embodiment, the cross-sectional area of ​​the flow path 116 where the check valve element is located is reduced, thereby reducing the amount of plasticized material delivered from the flat screw 111 to the communicating hole 115. Furthermore, the complex flow path structure near the guide element of the flow path 116 that guides the operation of the check valve element can cause the plasticized material to stagnate near the guide element. While this stagnant plasticized material is difficult to completely remove even when a cleaning agent or the next material is added from the hopper 30, it can gradually mix with the plasticized material passing near the guide element. For example, when a molded product is molded using a black first material and then a white second material, the black first material that has stagnated near the guide element can gradually mix with the white second material. In contrast, in this embodiment, the valve portion 170 is configured to be able to move forward and backward, so that by moving the valve portion 170 back toward the flat screw 111 during delivery, it is possible to prevent a decrease in the amount of plasticized material delivered or stagnation.

[0048] Furthermore, in this embodiment, the valve portion 170 is configured to move forward and contact the barrel 112 while blocking the communication hole 115. Therefore, by bringing the valve portion 170 into contact with the barrel 112 during injection, backflow can be more reliably suppressed.

[0049] Furthermore, in this embodiment, the valve portion 170 is configured to close the communicating hole 115 by having the bottom portion 232 of the protrusion 230 come into contact with the wall portion of the inlet end portion 115a of the communicating hole 115 when the tip portion 231 of the protrusion 230 is disposed within the communicating hole 115. Therefore, particularly when a guide groove 211 connected to the communicating hole 115 is formed, the protrusion 230 can effectively close the communicating hole 115 while isolating the communication between the guide groove 211 and the communicating hole 115.

[0050] Furthermore, in this embodiment, the valve portion 170 has a first screw portion 178 that screws into the second screw portion 208 of the opening 206, and is configured to move in the first direction D1 and the second direction D2 by rotating the first screw portion 178 relative to the second screw portion 208. Therefore, by rotating the first screw portion 178 relative to the second screw portion 208, the communication hole 115 can be easily opened and closed by the valve portion 170.

[0051] Furthermore, in this embodiment, the control unit 500 separately controls the valve motor 181 and the drive motor 118. Therefore, with a simple configuration, the valve unit 170 and the flat screw 111 can be operated separately.

[0052] Furthermore, in this embodiment, the control unit 500 controls the drive motor 118 and the valve unit motor 181 so that the rotation speed of the flat screw 111 and the rotation speed of the first screw unit 178 are the same during delivery. In this way, the first screw unit 178 does not rotate relative to the flat screw 111 during delivery, so the position of the valve unit 170 in the first direction D1 can be fixed with respect to the flat screw 111. In other words, the degree to which the valve unit 170 protrudes with respect to the flat screw 111 during delivery can be fixed. This makes it possible to further suppress the valve unit 170 from affecting the flow of the plasticized material during delivery.

[0053] Furthermore, in this embodiment, when closing the communication hole 115, the control unit 500 controls the valve unit motor 181 to stop the rotation of the flat screw 111 and then move the valve unit 170 in the first direction D1. Therefore, for example, compared to a case in which the valve unit 170 is moved in the first direction D1 while the flat screw 111 is rotating and then the rotation of the flat screw 111 is stopped, it is possible to move the valve unit 170 in the first direction D1 and close the communication hole 115 with simpler control. More specifically, when the valve unit 170 is moved in the first direction D1 while the flat screw 111 is rotating and then the rotation of the flat screw 111 is stopped, the control unit 500 first controls the drive motor 118 and the valve unit motor 181 so that the rotation speed of the valve unit 170 is greater than the rotation speed of the flat screw 111. Thereafter, the control unit 500 matches the rotation speed of the valve unit 170 with the rotation speed of the flat screw 111 so that the valve unit 170 does not move in the second direction D2, and stops the rotation of the flat screw 111 and the rotation of the valve unit 170. In contrast, in this embodiment, the flat screw 111 is stopped before the valve unit 170 is moved in the first direction D1, so that the communication hole 115 can be closed without the need for such complex control.

[0054] Furthermore, in this embodiment, the first screw portion 178 and the second screw portion 208 are configured so that when the flat screw 111 rotates in a predetermined rotational direction relative to the valve portion 170 while the first screw portion 178 and the second screw portion 208 are threaded together, the valve portion 170 moves in the second direction D2 relative to the flat screw 111. Therefore, by continuing to rotate the valve portion motor 181 even after the rotation of the flat screw 111 has stopped as described above, the valve portion 170 can be moved in the first direction D1, and the communication hole 115 can be closed by the valve portion 170. Therefore, the valve portion 170 can be moved in the first direction D1 and the communication hole 115 can be closed by even simpler control.

[0055] Furthermore, in this embodiment, the control unit 500 starts the injection operation after the communication hole 115 is closed by the valve unit 170. Therefore, compared to a configuration in which the injection operation is started before the communication hole 115 is closed by the valve unit 170, backflow of the plasticized material into the flat screw 111 during injection can be more effectively suppressed.

[0056] Furthermore, in this embodiment, since the transmission mechanism 140 configured as a belt mechanism is provided, the central axis RX and the drive shaft 119 can be easily disposed at positions offset from each other on the XZ plane. Therefore, interference between the valve motor 181 and the drive motor 118 can be easily prevented.

[0057] B. Second embodiment: 8 is a cross-sectional view showing a schematic configuration of a valve portion 170b in the second embodiment. In this embodiment, unlike the first embodiment, a main body portion 171b of the valve portion 170b has a first portion 173, a second portion 174, and a connecting portion 175. In addition, the flat screw 111b has a ring member 240. The material supply device 100 and the injection molding apparatus 10 in the second embodiment are similar to those in the first embodiment except for the points not specifically described.

[0058] In this embodiment, the first portion 173 has a substantially cylindrical shape. The first portion 173 has a first screw portion 178. The first screw portion 178 is provided on the outer circumferential surface of the first portion 173.

[0059] In this embodiment, the second portion 174 has a substantially cylindrical shape. The second portion 174 is disposed on the first direction D1 side, i.e., on the +Y direction side, of the first portion 173. The second portion 174 does not have a threaded portion such as the first threaded portion 178. In other words, the outer peripheral surface of the second portion 174 does not have a thread groove that screws into the second threaded portion 208.

[0060] The connecting portion 175 rotatably connects the first portion 173 and the second portion 174 to each other. In this embodiment, the connecting portion 175 is configured as a joint member having a spherical portion that connects the first portion 173 and the second portion 174 to each other rotatably around the rotation axis AX. In other embodiments, the connecting portion 175 may be configured by various bearings such as a needle bearing or a ball bearing.

[0061] The ring member 240 is provided at the end of the opening 206 of the flat screw 111b on the first direction D1 side, i.e., the end on the +Y direction side. The ring member 240 is configured as a metal O-ring. The ring member 240 is disposed so that its axial direction is along the Y direction. The inner peripheral surface 241 of the ring member 240 is configured as a smooth surface without any thread grooves. The second portion 174 is configured to be slidable within the opening of the ring member 240 in the first direction D1 and the second direction D2. More specifically, the second portion 174 is configured to be slidable within the opening of the ring member 240 while the outer peripheral surface of the second portion 174 and the inner peripheral surface 241 of the ring are in close contact with each other to an extent that the plasticized material is prevented from entering between the outer peripheral surfaces of the second portion 174 and the inner peripheral surface 241 of the ring.

[0062] In this embodiment, similarly to the first embodiment, the valve portion 170b moves in the Y direction as a result of the rotation of the first screw portion 178 that is threaded onto the second screw portion 208. However, in this embodiment, the first screw portion 178 and the second screw portion 208 are rotatably connected to each other by the connecting portion 175, and therefore the rotation of the first screw portion 178 is not transmitted to the second screw portion 208. As a result, the second screw portion 208 does not rotate around the rotation axis AX, but moves in the Y direction as the first screw portion 178 moves in the Y direction so as to slide within the opening of the ring member 240.

[0063] According to the material supply device 100 in the second embodiment described above, the valve portion 170b has a first portion 173 having a first thread portion 178, a second portion 174 that is arranged on the first direction D1 side of the first portion 173 and does not have a thread portion, and a connecting portion 175 that rotatably connects the first portion 173 and the second portion 174 to each other. According to this embodiment, because the second portion 174 that does not have a thread portion is arranged on the first direction D1 side of the first portion 173, it is possible to prevent the plasticized material from entering the opening 206 via the thread portion.

[0064] In this embodiment, a ring member 240 is provided at the end of the opening 206 on the first direction D1 side, and the second part 174 is configured to be slidable in the first direction D1 and the second direction D2 within the opening of the ring member 240. This makes it possible to further prevent the plasticized material from entering the opening 206 via the threaded portion.

[0065] C. Other Embodiments: (C-1) In each of the above embodiments, the valve unit 170 is configured to move in the first direction D1 and the second direction D2 by rotating the first screw portion 178 provided on the valve unit 170 relative to the second screw portion 208 while threading with the second screw portion 208 provided on the flat screw 111. However, the valve unit 170 does not have to be configured in this manner. For example, the valve unit 170 may be connected to various cylinder devices such as an air cylinder, a hydraulic cylinder, or an electromagnetic cylinder, and may be configured to move in the first direction D1 and the second direction D2 by being driven by the cylinder device. In this case, the material supplying apparatus 100 may not have a motor such as the valve unit motor 181. Furthermore, for example, the valve unit 170 may be configured to move in the first direction D1 and the second direction D2 by a rack-and-pinion or ball-screw mechanism. That is, in these cases, the material supplying apparatus 100 may not have the first screw portion 178 and the second screw portion 208.

[0066] (C-2) In the second embodiment, the flat screw 111b does not have to have the ring member 240.

[0067] (C-3) In each of the above embodiments, the control unit 500 controls the drive motor 118 and the valve motor 181 so that the rotation speed of the flat screw 111 and the rotation speed of the first screw portion 178 are the same during delivery. In contrast, the control unit 500 does not have to make the rotation speed of the flat screw 111 and the rotation speed of the first screw portion 178 the same during delivery. For example, the control unit 500 may move the valve portion 170 in the first direction D1 and the second direction D2 relative to the flat screw 111 to an extent that the valve portion 170 does not block the communication hole 115 during all or part of the delivery period.

[0068] (C-4) In each of the above embodiments, the thread groove of the first screw portion 178 and the thread groove of the second screw portion 208 may be configured so that when the flat screw 111 rotates in a predetermined rotational direction relative to the valve portion 170 while the first screw portion 178 and the second screw portion 208 are threaded together, the valve portion 170 moves in the first direction D1 relative to the flat screw 111.

[0069] (C-5) In each of the above embodiments, when closing the communication hole 115 with the valve unit 170, the control unit 500 controls the valve unit motor 181 to move the valve unit 170 in the first direction D1 after stopping the rotation of the flat screw 111. However, the control unit 500 does not have to control the rotation of the flat screw 111 and the valve unit motor 181 in this manner. For example, when closing the communication hole 115 with the valve unit 170, the control unit 500 may move the valve unit 170 in the first direction D1 while keeping the flat screw 111 rotating, and then stop the rotation of the flat screw 111 after the valve unit 170 closes the communication hole 115.

[0070] (C-6) In each of the above embodiments, the control unit 500 starts the injection operation after the communication hole 115 is closed by the valve unit 170, but this does not have to be the case. For example, the control unit 500 may start the injection operation at the same time as the communication hole 115 is closed by the valve unit 170. Alternatively, the control unit 500 may start the injection operation before the communication hole 115 is closed by the valve unit 170, and then close the communication hole 115 by the valve unit 170.

[0071] (C-7) In the above embodiments, the protrusion 230 contacts the barrel 112 so as to block the communicating hole 115, thereby closing the communicating hole 115, but this is not limited to this. For example, the communicating hole 115 may be closed by the end face 172 contacting the opposing surface 212 of the barrel 112 so as to block the communicating hole 115. In this embodiment, if a guide groove 211 connected to the communicating hole 115 is provided in the opposing surface 212, it is preferable that the end face 172 be configured to block the guide groove 211 in the closed state. Furthermore, as described above, the valve portion 170 and the barrel 112 do not have to be in contact with each other in the closed state.

[0072] (C-8) In each of the above embodiments, the injection control unit may be configured separately from the control unit 500. For example, the injection control unit may be configured by a computer or circuit separate from the control unit 500.

[0073] D. Other forms: The present disclosure is not limited to the above-described embodiments and can be realized in various forms without departing from the spirit thereof. For example, the present disclosure can also be realized in the following forms. The technical features in the above embodiments corresponding to the technical features in each form described below can be appropriately replaced or combined to solve some or all of the problems of the present disclosure or to achieve some or all of the effects of the present disclosure. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0074] (1) According to a first aspect of the present disclosure, there is provided a material supplying device. The material supplying device includes a drive motor, a screw having a grooved surface with grooves formed therein and rotated by the drive motor, a barrel having an opposing surface facing the grooved surface and formed with a communication hole through which a plasticized material flows, a nozzle communicating with the communication hole and injecting the plasticized material to the outside, and a valve unit provided on the screw. The valve unit is configured to be able to move forward in a first direction from the screw toward the communication hole and to move backward in a second direction opposite to the first direction, and the valve unit is configured to open and close the communication hole by the forward movement and the backward movement. According to this embodiment, the communicating hole can be opened by retracting the valve portion in the second direction when the plasticized material is delivered from the screw to the barrel, and the communicating hole can be closed by advancing the valve portion in the first direction when the plasticized material is injected to the outside through the nozzle. Therefore, backflow of the plasticized material from the nozzle side to the screw side during injection can be suppressed, and the valve portion can be suppressed from affecting the flow of the plasticized material during delivery.

[0075] (2) In the above aspect, the valve portion may be configured to block the communication hole while contacting the barrel by the forward movement. According to this aspect, by bringing the valve portion into contact with the barrel during injection, backflow can be more reliably suppressed.

[0076] (3) In the above aspect, the screw may have an opening that opens toward the barrel and accommodates at least a portion of the valve portion, a first threaded portion provided on an outer peripheral surface of the valve portion, and a second threaded portion that threadably engages with the first threaded portion on an inner peripheral surface of the opening, and the valve portion may be configured to perform the forward movement and the backward movement by rotating the first threaded portion relative to the second threaded portion around a rotation axis along the first direction. According to this aspect, the communication hole can be easily opened and closed by the valve portion by rotating the first threaded portion relative to the second threaded portion.

[0077] (4) In the above embodiment, the valve portion may have a first portion, a second portion disposed on the first direction side of the first portion, and a connecting portion connecting the first portion and the second portion, wherein the first portion has the first threaded portion and the second portion does not have a threaded portion, and the connecting portion connects the first portion and the second portion to each other so as to be rotatable around the rotation axis. According to this embodiment, since the second portion not having a threaded portion is disposed on the first direction side of the first portion having the first threaded portion, it is possible to prevent the plasticized material from entering the opening through the threaded portion.

[0078] (5) In the above embodiment, the screw may have a ring member provided at an end of the opening on the first direction side, and the second portion may be configured to be slidable within the opening of the ring member in the first direction and the second direction. This embodiment can further prevent the plasticized material from entering the opening through the threaded portion.

[0079] (6) In the above embodiment, the valve motor may further include a valve portion motor for rotating the first screw portion, and a control unit for individually controlling the drive motor and the valve portion motor. According to this embodiment, the valve portion and the screw can be operated individually with a simple configuration.

[0080] (7) In the above embodiment, the control unit may control the drive motor and the valve motor so that the rotation speed of the screw and the rotation speed of the first screw portion are the same when the plasticized material is being delivered from the screw to the barrel. According to this embodiment, the first screw portion does not rotate relative to the screw when the plasticized material is being delivered, so the position of the valve portion in the first direction can be fixed relative to the screw. Therefore, the influence of the valve portion on the flow of the plasticized material when the plasticized material is being delivered can be further suppressed.

[0081] (8) In the above embodiment, when closing the communication hole, the control unit may control the valve unit motor to move the valve unit in the first direction after stopping rotation of the screw. According to this embodiment, the valve unit can be moved in the first direction and the communication hole can be closed with simpler control than when the valve unit is moved in the first direction while the screw is rotating.

[0082] (9) In the above embodiment, the injection device includes a cylinder communicating with the communication hole and the nozzle, a plunger moving within the cylinder, and an injection control unit that controls the injection device to perform a suction operation of sucking the plasticized material from the communication hole into the cylinder by the movement of the plunger, and an injection control unit that starts the injection operation after the communication hole is closed by the valve unit. This embodiment can more effectively suppress backflow of the plasticized material into the screw during injection.

[0083] (10) According to a second aspect of the present disclosure, there is provided an injection molding apparatus including the material supply device of the above aspect and a mold clamping device that opens and closes a mold into which the plasticized material is injected from the nozzle. [Explanation of symbols]

[0084] 10...injection molding apparatus, 30...hopper, 100...material supply device, 101...storage section, 110...plasticization section, 111, 111b...flat screw, 112...barrel, 113...heater, 114...nozzle, 115...communicating hole, 115a...inlet side end, 116...flow path, 118...drive motor, 119...drive shaft, 120...injection section, 121...cylinder, 122...plunger, 123...plunger drive section, 130...mold clamping device, 131...mold drive section, 132...ball screw, 140...transmission mechanism, 141...first pulley, 142...second pulley, 143...transmission belt, 1 60...forming die, 161...fixed die, 162...movable die, 170, 170b...valve portion, 171, 171b...main body portion, 172...end surface, 173...first portion, 174...second portion, 175...connecting portion, 177...outer surface, 178...first screw portion, 181...valve portion motor, 201...groove forming surface, 202...groove, 203...material inlet, 204...ridge portion, 205...center portion, 206...opening, 207...inner surface, 208...second screw portion, 211...guide groove, 212...opposing surface, 230...projection portion, 231...tip portion, 232...hem portion, 240...ring member, 241...ring inner surface, 500...control portion

Claims

1. A drive motor; a screw having a groove forming surface on which grooves are formed and rotated by the drive motor; a barrel having an opposing surface facing the groove forming surface and having a communication hole formed therein through which a plasticized material flows; a nozzle communicating with the communication hole and configured to inject the plasticized material to the outside; a valve portion provided on the screw, the valve portion is configured to be capable of moving forward in a first direction from the screw toward the communication hole and moving backward in a second direction opposite to the first direction, The valve portion is configured to open and close the communication hole by the forward movement and the backward movement.

2. The material supply device according to claim 1, The valve portion is configured to contact the barrel and close the communication hole by the forward movement.

3. The material supply device according to claim 1, the screw has an opening that opens toward the barrel and accommodates at least a portion of the valve portion; a first threaded portion is provided on an outer circumferential surface of the valve portion; a second threaded portion that threadably engages with the first threaded portion is provided on an inner circumferential surface of the opening; A material supply device wherein the valve portion is configured to perform the forward movement and the backward movement by rotating the first screw portion relative to the second screw portion around a rotation axis along the first direction.

4. The material supply device according to claim 3, the valve portion has a first portion, a second portion disposed on the first direction side of the first portion, and a connecting portion connecting the first portion and the second portion, the first portion has the first threaded portion, the second portion does not have a threaded portion; The connecting portion connects the first part and the second part to each other so as to be rotatable about the rotation axis.

5. The material supply device according to claim 4, the screw has a ring member provided at an end of the opening on the first direction side, The second portion is configured to be slidable in the first direction and the second direction within the opening of the ring member.

6. The material supply device according to claim 3, further comprising: a valve portion motor for rotating the first screw portion; a control unit that individually controls the drive motor and the valve motor.

7. The material supply device according to claim 6, The control unit controls the drive motor and the valve motor so that the rotation speed of the screw and the rotation speed of the first screw portion are the same when the plasticized material is discharged from the screw to the barrel, a material supply device.

8. The material supply device according to claim 6, A material supplying device, wherein the control unit controls the valve portion motor so that the valve portion moves in the first direction after stopping rotation of the screw when closing the communication hole.

9. The material supply device according to claim 1, further comprising: an injection unit having a cylinder communicating with the communication hole and the nozzle, and a plunger moving within the cylinder, wherein a suction operation of sucking the plasticized material from the communication hole into the cylinder by the movement of the plunger, and an injection operation of injecting the plasticized material sucked into the cylinder to the outside via the nozzle; an injection control unit that controls the injection unit, The injection control unit starts the injection operation after the communication hole is closed by the valve unit.

10. 1. An injection molding apparatus comprising: The material supply device according to any one of claims 1 to 9; and a mold clamping device that opens and closes a mold into which the plasticized material is injected from the nozzle.

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