Material transfer device

Abstract

To provide a material transfer device 10 that is compact and easy to move. [Solution] A material transfer device comprising: a tank (20) having an exhaust tube section (411), a suction tube section (311), and a discharge section (33), which stores material sucked in from the suction tube section (311) and can discharge the stored material to the outside from the discharge section (33); and an ejector (21) connected to the exhaust tube section (411) and exhausts air from within the tank (20), wherein the ejector (21) exhausts air from within the tank (20) through the exhaust tube section (411), creating negative pressure within the tank (20), and sucks the material into the tank (20) from the suction tube section (311), wherein the ejector (21) is installed integrally with the tank (20).

Description

[Technical Field]

[0001] The present invention relates to a material transfer device. [Background technology]

[0002] Patent Document 1 describes a material supplying device for supplying molding material to a hopper of an injection molding machine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-108301 Summary of the Invention [Problem to be solved by the invention]

[0004] The material supply device of Patent Document 1 has a hopper placed above a tank, and a blower creates negative pressure inside the hopper to suck in the material, and then stops blowing air from the blower to allow the material stored in the hopper to move to the tank by its own weight.

[0005] However, in this material supply device, the blower is installed separately from the hopper, which makes the material supply device large and complicated, and also makes it necessary to move the blower separately when moving the hopper, which makes the operation cumbersome.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a material transfer device that is compact and easy to move. [Means for solving the problem]

[0007] One of the above-mentioned solutions is a material transfer device comprising: a container having an exhaust port, a material suction port, and a material discharge port, which stores the material sucked in through the material suction port and can discharge the stored material to the outside through the material discharge port; and an exhaust device connected to the exhaust port and exhausting gas within the container, wherein the exhaust device exhausts the gas within the container through the exhaust port to create a negative pressure within the container, and the material is sucked into the container through the material suction port, and the exhaust device is installed integrally with the container.

[0008] In the second solution, the exhaust device is installed integrally with the container via a mounting frame fixed to the container. The third solution has a material filtering filter between the exhaust port and the material suction port inside the container.

[0009] In the fourth solution, the container has an air intake port on the exhaust port side of the material filter, and the air intake port is connected to an air supply device. The fifth solution is a method for cleaning a material filter of a material transfer device using the material transfer device, which includes a suction process in which the exhaust device exhausts gas from within the container through the exhaust port to create a negative pressure within the container, and then sucks the material into the container through the material suction port, and a cleaning process in which, after the suction process, the air supply device supplies gas from the air supply port into the container, and then removes the material adhering to the material filter. [Effects of the Invention]

[0010] The material transfer device of the present invention is compact and easy to move. [Brief explanation of the drawings]

[0011] [Figure 1] Schematic diagram of a material transfer device installed in an injection molding machine. [Figure 2] Schematic diagram of a material transfer device. [Figure 3] Schematic diagram of a material transfer device, focusing on the tank. [Figure 4] FIG. 2 is a schematic plan view of the material transfer device, focusing on the tank. [Figure 5] Figure 5(a) is a cross-sectional schematic diagram of the filter unit, and Figure 5(b) is a plan schematic diagram of the same. [Figure 6] 1 is a flow diagram of the operation of a material transfer device. [Figure 7] Figures 7(a) to 7(f) are explanatory diagrams of the tank state. [Figure 8] 1 is a flow diagram of the operation of a material transfer device. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment in which the present invention is embodied in a material transfer device 10 used in an injection molding machine 700 will be described below with reference to FIGS. FIG. 1 shows a schematic diagram of a material transfer device 10 installed in an injection molding machine 700. The injection molding machine 700 shown in the figure includes a cylinder 701, inside which a screw 702 for feeding material m is installed rotatably by a motor (not shown). A hopper 703 for storing material m fed into the cylinder 701 is installed at the base end of the cylinder 701. A mold 704 is installed at the tip of the cylinder 701, and material m melted by a heater (not shown) installed in the cylinder 701 is poured into the mold 704 for molding. The hopper 703 has a roughly inverted cone shape, with its lower end connected to the interior of the cylinder 701 and its upper end open. The material transfer device 10 is installed above the hopper 703. The material m to be transferred by the material transfer device 10 of this embodiment is a plastic material for injection molding, such as resin pellets, pulverized material, or powder. The particle size of the powder is, for example, 100 to 200 μm.

[0013] (Regarding material transfer device 10) FIG. 2 shows a schematic diagram of the material transfer device 10. The material transfer device 10 includes a tank 20 as a container that can suck material m into the tank 20, temporarily store the sucked material m, and discharge the stored material m to the outside. The material transfer device 10 also includes an ejector 21 as an exhaust device that creates a negative pressure inside the tank 20, a solenoid valve unit 22 that starts and stops the supply of compressed air ca, and a detection sensor 23 that detects the height of the upper surface of material m in the hopper 703. The material transfer device 10 also includes a compressor 24 as an air supply device that generates and supplies compressed air ca, and a control unit 25 that controls the solenoid valve unit 22 and other components. In the following description, when referring to the tank 20, terms such as "discharge" and "exhaust" refer to the movement of material m or air a (gas) from inside the tank 20 to outside the tank 20, and terms such as "suction" and "air supply" refer to the movement of material m or air a from outside the tank 20 to inside the tank 20.

[0014] (About Tank 20) 1 to 3, the tank 20 includes a metal tank body 30, a metal tank cover 40, a filter unit 50 disposed between the tank body 30 and the tank cover 40, and a metal mounting portion 60. Note that the filter unit 50 is located inside the tank 20 and cannot be seen from the outside, and is therefore indicated by a dashed line in FIG.

[0015] (Regarding the tank body 30) 3, the tank body 30 integrally comprises a cylindrical main body portion 31, an inverted cone-shaped tapered portion 32 located at the bottom of the main body portion 31, a discharge portion 33 serving as a material discharge port located at the bottom of the tapered portion 32, and a filter receiving portion 34 located at the top of the main body portion 31. The interior of the tank body 30 forms a storage space for temporarily storing the material m to be transported.

[0016] 3 and 4, a suction tube 311 serving as a material suction port is formed laterally near the top of the main body tube 31, opening into the interior of the main body tube 31. The suction tube 311 is cylindrical and made of metal, and its axis is perpendicular to but does not intersect with the axis of the main body tube 31, and is formed along a tangent to the inner peripheral surface of the main body tube 31. As shown in FIG. 2, a suction hose 312 is connected to the suction tube 311. The other end of the suction hose 312 is located in the stock area S where the material m is stocked, and the material m from the stock area S can be sucked into the tank 20.

[0017] As shown in Figures 3 and 4, an ejector mounting frame 313, a solenoid valve mounting frame 314, and four adjusting fasteners 315 are fixed to the outer circumferential surface of the cylindrical main body 31. The ejector mounting frame 313 and the solenoid valve mounting frame 314 are metal frames formed into predetermined shapes for fixing the ejector 21 and the solenoid valve unit 22 to the tank 20, respectively, and are fixed by welding at locations 180 degrees apart around the circumference of the cylindrical main body 31. The ejector 21 is installed in the tank 20 via the ejector mounting frame 313, and the solenoid valve unit 22 is installed via the solenoid valve mounting frame 314. The adjusting fasteners 315 are locking devices for fixing the tank main body 30 and the tank cover 40 together, and their tips can be hooked onto hooks 423 fixed to the tank cover 40. The adjusting fasteners 315 have adjustable interference lengths. In this embodiment, the adjusting fasteners 315 do not include the hooks 423.

[0018] 3 and 4, four adjusting fasteners 315 are fixed at 90-degree intervals in the circumferential direction to the outer circumferential surface of the tubular main body portion 31. Each adjusting fastener 315 is fixed in a position where it does not interfere with the ejector mounting frame 313, the solenoid valve mounting frame 314, and the suction tubular portion 311. As shown in Fig. 3, the tapered portion 32 is formed continuously at the lower end of the tubular main body portion 31, and has an inverted conical cylindrical shape whose inner diameter decreases downward.

[0019] As shown in FIG. 3, the discharge section 33 includes a cylindrical discharge tube section 331 and a tank on-off valve 332 connected below it. The discharge section 33 serves as a flow path for discharging the material m from the tank 20 to the outside. The upper end of the discharge tube section 331 is continuous with the lower end of the tapered section 32, and the axis of the discharge tube section 331 coincides with the axis of the main body tube section 31. The tank on-off valve 332 is a ball valve unit having a hollow ball (see FIG. 7) in the flow path, and is an air-driven type in which compressed air ca drives a cylinder (not shown) to rotate the ball and open and close the valve. The tank on-off valve 332 opens when compressed air ca is not supplied and closes when compressed air ca is supplied. As shown in FIG. 2, the tank on-off valve 332 is connected to the solenoid valve unit 22 via an air tube 333 for supplying compressed air ca.

[0020] 3 and 4, the lower end of the discharge tube portion 331 and the upper end of the tank on-off valve 332 are joined by flanges 331a, 332b formed at each end. A pair of suspension frames 334 that extend radially outward and have a fan shape in a plan view are fixed to the underside of the flange 332b of the tank on-off valve 332. Bolt holes and hook holes (not shown) are formed in the suspension frame 334, and the tank 20 can be lifted by engaging suspension bolts in the bolt holes or by hooking a hook of a hoist in the hook hole.

[0021] As shown in Figure 5(a), the filter receiving portion 34 is formed continuously with the upper end of the main body tubular portion 31, and comprises an annular receiving plate 341 extending radially outward from the upper edge of the main body tubular portion 31, and a cylindrical inner wall 342 extending upward from the outer edge of the receiving plate 341.

[0022] (About the tank cover 40) As shown in Figures 3 and 4, the tank cover 40 is integrally provided with a cover main body 41 and a filter pressing portion 42 located at the bottom of the cover main body 41. The cover main body 41 is a cylinder with a closed top surface, and its diameter is the same as that of the main body cylindrical portion 31. An exhaust pipe portion 411 constituting an exhaust port is formed in the center of the top surface of the cover main body 41, extending upward from the cover main body 41, and its lower end opens downward from the cover main body 41. The exhaust pipe portion 411 is cylindrical and made of metal, and is coaxial with the axis of the cover main body 41. As shown in Figure 2, the exhaust pipe portion 411 is connected to the ejector 21 via an exhaust hose 412.

[0023] Furthermore, air intake cylinder sections 413 are formed as air intake ports at four locations on the circumference of a circle centered on the exhaust cylinder section 411 on the top surface of the cover main body 41, extending upward from the cover main body 41, with their lower ends opening downward from the cover main body 41. Each air intake cylinder section 413 is a metal cylinder with a smaller diameter than the exhaust cylinder section 411 and is parallel to the exhaust cylinder section 411. As shown in Figure 2, each air intake cylinder section 413 is connected to the solenoid valve unit 22 via an air tube 414 for supplying compressed air CA.

[0024] As shown in FIG. 5(a), the filter pressing portion 42 is formed contiguous with the lower end of the cover body 41 and includes an annular pressing plate 421 extending radially outward from the lower edge of the cover body 41 and a cylindrical outer wall 422 extending downward from the outer edge of the pressing plate 421. The filter pressing portion 42 is formed with a diameter that allows the filter receiving portion 34 of the tank body 30 to fit over it. Therefore, the inner diameter of the outer wall 422 of the filter pressing portion 42 is larger than the outer diameter of the inner wall 342 of the filter receiving portion 34. As shown in FIG. 4, hooks 423 are fixed to the outer peripheral surface of the outer wall 422 of the filter pressing portion 42 at four locations spaced 90 degrees apart in the circumferential direction. These hooks 423 are used to hook and secure the adjustment fasteners 315 fixed to the tank body 30. The tank cover 40 is fixed to the tank body 30 by hooking the adjustment fastener 315 to the hook 423, and the tank cover 40 can be removed from the tank body 30 by releasing the hook.

[0025] (About the filter unit 50) 5(a) shows a cross-sectional view of filter unit 50. Filter unit 50 includes filter frame 51, two reinforcing plates 52, and filter 53 as a material filtration filter sandwiched between both reinforcing plates 52. In filter unit 50, filter 53 is sandwiched between two reinforcing plates 52 on both sides, and the end faces and a certain region of the outer periphery of the two reinforcing plates 52 sandwiching filter 53 are further surrounded by filter frame 51.

[0026] The filter frame 51 is integrally formed with a cylindrical frame body 511 and annular ribs 512 that extend radially inward in parallel from both the upper and lower edge portions of the frame body 511, forming a U-shaped cross section. The filter frame 51 is made of silicone with a uniform thickness and is elastic. The outer diameter of the filter frame 51 is slightly smaller than the inner diameter of the filter receiving portion 34. The height of the filter frame 51 (the length in the vertical direction in FIG. 5(a)) is slightly greater than the height of the filter receiving portion 34. The length (radial length) of the ribs 512 of the filter frame 51 is approximately the same as the length (radial length) of the receiving plate 341 of the filter receiving portion 34.

[0027] FIG. 5(b) shows a plan view of the filter unit 50. Each reinforcing plate 52 is a circular metal plate with multiple through holes 521 formed therein. In FIG. 5(b), only some of the through holes 521 are labeled. The two reinforcing plates 52 are identical in shape, and the sizes and positions of the through holes 521 are also the same. The diameter of the reinforcing plate 52 is the same as the inner diameter of the frame body 511 of the filter frame 51. Furthermore, the through holes 521 are not formed in a certain radial region from the outer periphery of the reinforcing plate 52 (the region covered by the ribs 512 of the filter frame 51). The reinforcing plate 52 reinforces the filter 53 while allowing air a to pass vertically across the filter 53 in FIG. 5(a) at the locations of the through holes 521. The filter 53 is made of a circular nonwoven fabric with the same diameter as the reinforcing plate 52 and has the ability to block the passage of material m sucked into the tank 20 while allowing the passage of air a. The mesh size of the filter 53 may be determined appropriately depending on the size (particle size) of the material m to be sucked.

[0028] As shown in FIG. 5(a), the filter unit 50 is placed on the filter receiving portion 34 of the tank body 30. In this state, the lower surfaces of the ribs 512 of the filter frame 51 of the filter unit 50 are seated in a circular shape on the receiving plate 341 of the filter receiving portion 34. The multiple through holes 521 formed in the two reinforcing plates 52 are arranged in positions that overlap in the thickness direction, and as shown in FIG. 5(b), the filter 53 is exposed from the through holes 521. As shown in FIG. 5(a), the filter pressing portion 42 of the tank cover 40 is attached by fitting it externally to the filter receiving portion 34 of the tank body 30, and the pressing plate 421 of the filter pressing portion 42 abuts in a circular shape against the upper surface of the ribs 512 of the filter frame 51 of the filter unit 50.

[0029] As shown in Figure 4, the tank body 30 and tank cover 40 can be fixed at four circumferential locations by engaging adjustment fasteners 315 with hooks 423. The engagement of adjustment fasteners 315 with hooks 423 acts to bring the filter receiving portion 34 of the tank body 30 and the filter holding portion 42 of the tank cover 40 closer to each other. The filter frame 51 is sandwiched between the filter receiving portion 34 and the filter holding portion 42 and elastically deforms to form a tight fit, so air a can pass between the tank body 30 and the tank cover 40 only in the area where the filter 53 exposed from the through-hole 521 is located. When the tank cover 40 is removed from the tank body 30, the filter unit 50 can also be removed from the tank 20.

[0030] (Regarding the placement section 60) 2 to 4, the placing portion 60 is a metal disk installed at the lower end of the discharge portion 33, with a circular hole (not shown) formed therethrough at a position corresponding to the discharge portion 33. The placing portion 60 serves as a lid when the material transfer device 10 is placed on the upper edge of a hopper 703 of the injection molding machine 700, and has a diameter larger than that of the hopper 703. A detection sensor 23 is installed on the placing portion 60, facing downward.

[0031] (About Ejector 21) As shown in FIGS. 2 and 3, the ejector 21 has a compressed air inlet 211, an air outlet 212, and a suction port 213. The pressure of compressed air ca introduced through the compressed air inlet 211 decreases as it passes through the inside of the ejector 21, and external air a is sucked in through the suction port 213 and discharged to the outside of the ejector 21 through the air outlet 212. Such an ejector 21 is well known, and a commercially available product (e.g., the CVZ series from Convum Co., Ltd.) can be used as the ejector 21 of this embodiment. As shown in FIG. 2, the compressed air inlet 211 of the ejector 21 is connected to the solenoid valve unit 22 via an air tube 214 for supplying compressed air ca. The suction port 213 of the ejector 21 is connected to an exhaust tube portion 411 of the tank cover 40 via an exhaust hose 412.

[0032] (Regarding the solenoid valve unit 22) As shown in Fig. 3, the solenoid valve unit 22 has a configuration in which a first solenoid valve 221, a second solenoid valve 222, and a third solenoid valve 223 are arranged in parallel. Each solenoid valve 221, 222, and 223 (hereinafter, when referring to each solenoid valve, only 221 will be referred to) has a valve that electromagnetically opens and closes an internal air flow path. Each solenoid valve 221 is electrically connected to the control unit 25, and performs opening and closing operations individually under the control of the control unit 25. Each solenoid valve 221 has an inlet 224 and an outlet 225 for compressed air CA. As shown in Fig. 2, each inlet 224 is connected to the compressor 24 via an air tube 226. The air tube 226 branches into three just before the solenoid valve unit 22 and is connected in parallel to the inlets 224 of each solenoid valve 221.

[0033] 2, the discharge port 225 of the first solenoid valve 221 is connected to the tank opening / closing valve 332 via an air tube 333, and the discharge port 225 of the second solenoid valve 222 is connected to the compressed air inlet 211 of the ejector 21 via an air tube 214. The discharge port 225 of the third solenoid valve 223 is connected to each of the four air supply cylinder sections 413 of the tank cover 40 via an air tube 414. The air tube 414 branches into four just before the four air supply cylinder sections 413 and is connected to each of the air supply cylinder sections 413.

[0034] (Regarding the detection sensor 23) 2, the detection sensor 23 is installed on the placement unit 60 and is directed toward the inside of the hopper 703 located below it. The detection sensor 23 is electrically connected to the control unit 25, and is activated and deactivated together with the control unit 25. The detection sensor 23 can detect the distance to the top surface of the material m in the hopper 703, i.e., the height of the material m stored in the hopper 703. The height of the material m in the hopper 703 detected by the detection sensor 23 includes a first position h1 and a second position h2 that is lower than the first position h1.

[0035] The first position h1 is a preset height at which the amount of material m stored in the hopper 703 has decreased to a certain level and the material transfer device 10 needs to transfer the material m into the hopper 703. The second position h2 is a height at which, for example, the volume of the material m in the hopper 703 reaches 60, assuming that the volume of the material m when the upper surface of the material m in the hopper 703 is at the first position h1 is 100. While the material transfer device 10 is operating, the height of the material m in the hopper 703 either fluctuates around the first position h1 or gradually increases from the first position h1. However, if, for example, the material m in the stock area S is broken or the suction hose 312 is disconnected from the stock area S, the material transfer device 10 cannot transfer the material m, and the height of the material m in the hopper 703 decreases. The second position h2 is provided to detect such a state. When the height of the material m in the hopper 703 reaches the first position h1 or the second position h2, the detection sensor 23 sends a detection signal to the control unit 25.

[0036] (About Compressor 24) The compressor 24 is a device that generates and supplies compressed air ca, is electrically connected to the control unit 25, and starts and stops together with the activation of the control unit 25. The compressor 24 is connected to the solenoid valve unit 22 via an air tube 226.

[0037] (Regarding the control unit 25) The control unit 25 is a device that controls the material transfer device 10 and is equipped with a start switch, a CPU (Central Processing Unit), a RAM (Random access memory), a ROM (Read only memory), and a buzzer (none of which are shown). The control unit 25 is electrically connected to the solenoid valve unit 22, the detection sensor 23, and the compressor 24. The start switch also serves as a stop switch.

[0038] (Operation of material transfer device 10) Next, a method for transferring material and a method for cleaning the filter of the material transfer device 10 used in the injection molding machine 700 will be described.

[0039] Since injection molding is performed continuously while the injection molding machine 700 is in operation, the material m stored in the hopper 703 decreases at a constant rate. For this reason, it is necessary to periodically transfer the material m to the hopper 703.

[0040] 6, when the control unit 25 is switched on, the material transfer device 10 is started (S101). Specifically, the solenoid valve unit 22, the detection sensor 23, and the compressor 24 are started up together with the control unit 25. When the compressor 24 is started up, it generates compressed air ca and pressure-feeds the compressed air ca to the solenoid valve unit 22. Note that the first solenoid valve 221, the second solenoid valve 222, and the third solenoid valve 223 are all closed at the time of start-up, and the compressed air ca is not pressure-feed beyond each solenoid valve 221.

[0041] The detection sensor 23 detects the height of the material m stored in the hopper 703 (S102), and when it detects the first position h1 as the height of the material m, it sends a detection signal to the control unit 25 (S103). When the control unit 25 receives this detection signal, it opens the first solenoid valve 221 (S104). When the first solenoid valve 221 opens, compressed air ca is pressure-fed to the tank opening / closing valve 332, and the tank opening / closing valve 332 closes as shown in Figure 7(a) (S105). Note that the tank 20 is empty and contains air a.

[0042] Next, the control unit 25 opens the second solenoid valve 222 (S106). When the second solenoid valve 222 is opened, compressed air ca is supplied to the compressed air inlet 211 of the ejector 21, and the ejector 21 begins suctioning air a from inside the tank through the suction port 213 (S107). Because the suction port 213 is connected to the exhaust tube portion 411 of the tank cover 40 via the exhaust hose 412, air a is sucked from the exhaust tube portion 411, creating a negative pressure inside the tank 20, as shown in FIG. 7(b). When the negative pressure is created inside the tank 20, suction of the suction tube portion 311 begins via the suction hose 312. The tip of the suction hose 312 is located in the stock area S, and a suction process is initiated in which material m is sucked from the suction tube portion 311 through the suction hose 312 (S108).

[0043] As shown in Figure 7(c), the material m sucked into the tank 20 swirls inside the tank body 30 while hitting the inner circumferential surface of the tank body 30, and as its kinetic energy is neutralized, it falls to the bottom of the tank body 30 and is stored in the tank 20. Meanwhile, air a is also sucked into the tank 20 along with the material m, but the air a passes through the filter 53 and is discharged outside the tank 20 from the exhaust pipe portion 411, and is sucked into the ejector 21. A portion of the material m sucked into the tank body 30 also moves together with the air a, but the material m is captured by the filter 53 and is prevented from being discharged outside the tank 20.

[0044] The control unit 25 closes the second solenoid valve 222 a certain time after the first solenoid valve 221 opens (S109). This certain time is the time it is assumed that the sucked material m will be stored in the tank 20 to a certain extent (for example, 40% of the capacity of the tank main body 30). As a result, the compressed air ca is no longer supplied to the ejector 21, and the ejector 21 stops suction (S110). Then, the negative pressure in the tank 20 is also eliminated, and the suction of the material m into the tank 20 also stops (S111). As shown in FIG. 7(d), the sucked material m is stored in the tank 20.

[0045] Next, the control unit 25 closes the first solenoid valve 221 (S112). Closing the first solenoid valve 221 opens the tank opening / closing valve 332 (S113). Then, as shown in FIG. 7(e), the material m stored in the tank 20 is discharged from the tank 20 through the discharge unit 33 and transferred to the hopper 703 (S114). The control unit 25 opens the third solenoid valve 223 after a certain time has elapsed since the first solenoid valve 221 was closed (S115). This certain time is the estimated time for all of the material m stored in the tank 20 to be discharged through the discharge unit 33. Opening the third solenoid valve 223 supplies compressed air ca from the air intake cylinder unit 413 into the tank 20 (S116). As shown in FIG. 7(f), the compressed air ca is supplied from the air supply cylinder 413 into the tank 20 in the opposite direction to the flow of air a during the previous suction (FIGS. 7(b) and 7(c)) relative to the filter 53. Therefore, the material m captured by the filter 53 during suction is removed from the filter 53 by receiving the compressed air ca flowing in the opposite direction to that during suction. This cleans the filter 53 (cleaning process). Then, after a further certain period of time has elapsed, the control unit 25 closes the third solenoid valve 223 (S117).

[0046] When the above steps are completed, the process returns to height detection by the detection sensor 23 (S102). If the operation of the injection molding machine 700 stops, the material transfer device 10 will stop operating regardless of which step is taken by turning off the start switch.

[0047] (Operation when the detection sensor 23 detects the second position h2) 8, the detection sensor 23 detects the position of the material m stored in the hopper 703 (S102), and when it detects the second position h2 as the height of the material m, it transmits a detection signal to the control unit 25 (S203). The control unit 25, which has received the detection signal, activates a buzzer (S204). An operator who hears the buzzer can take necessary action, such as checking the stock area S or stopping the injection molding machine 700 and / or the material transfer device 10 as necessary.

[0048] According to the material transfer device 10 of the above embodiment, the following effects can be obtained. (1) In the material transfer device 10 of the above embodiment, the ejector 21 that exhausts air a from the tank 20 and creates a negative pressure inside the tank 20 is installed integrally with the tank 20. This makes the material transfer device 10 compact, and the ejector 21 can be moved together with the tank 20, making it easy to move.

[0049] (2) The ejector 21 is fixed to the ejector mounting frame 313 that is fixed to the tank 20, and is installed integrally with the tank 20. This makes it easy to install the tank 20 and the ejector 21 integrally.

[0050] (3) A filter 53 is provided between the exhaust tube portion 411 and the suction tube portion 311 inside the tank 20. Therefore, the air a sucked from the suction tube portion 311 passes through the filter 53 and is exhausted to the outside of the tank 20, but the sucked material m is captured by the filter 53 and is prevented from being discharged to the outside of the tank 20.

[0051] (4) The tank 20 has an air intake tube 413 connected to the compressor 24. When using a pulverized material or powder with a small particle size as the material m, there is a possibility that the material m will pass through the filter 53 during suction, so the mesh size of the filter 53 needs to be fine. However, if the mesh size of the filter 53 is made fine, there is a risk that the material m with a small particle size will adhere to the filter 53 and cause clogging. To address this, compressed air ca from the compressor 24 is supplied into the tank 20 from the air intake tube 413 in a flow opposite to that during suction. Because the compressed air ca flows through the filter 53 in the opposite direction to that during suction, the material m that has adhered to the filter 53 during suction can be removed toward the tank main body 30, making it possible to clean the filter 53.

[0052] (5) The solenoid valve unit 22 is installed integrally with the tank 20. This makes the material transfer device 10 compact, and the solenoid valve unit 22 can be moved together with the tank 20, making it easy to move.

[0053] (6) In the filter unit 50, a filter 53 is sandwiched between two reinforcing plates 52. Each reinforcing plate 52 has a plurality of through holes 521 formed therein. Therefore, the filter 53 can filter air at the portions of the reinforcing plates 52 that are located at the through holes 521, and the filter 53 is less likely to deform during suction.

[0054] (7) The filter unit 50 has a filter frame 51 made of silicone and having elasticity, and this filter frame 51 is clamped between the filter receiving portion 34 of the tank body 30 and the filter pressing portion 42 of the tank cover 40. As a result, the filter frame 51 elastically deforms and adheres closely to the filter receiving portion 34 and the filter pressing portion 42, making it difficult for gaps to form.

[0055] (8) The tank 20 is detachable because the tank body 30 and the tank cover 40 are fixed with the adjustment fasteners 315 and the hooks 423. This makes maintenance inside the tank 20 easy.

[0056] (9) The axis of the suction tube portion 311 formed in the tank body 30 does not intersect with the axis of the main body tube portion 31, but is formed along a tangent to the inner peripheral surface of the main body tube portion 31. Therefore, the material m sucked from the main body tube portion 31 falls to the bottom of the tank body 30 due to the cyclone effect, making it easy to separate the sucked material m from the air a.

[0057] (10) Since the height of the material m accumulated in the hopper 703 is detected by the detection sensor 23, the material transfer device 10 can automatically transfer and stop the material m. The above embodiment may be modified as follows.

[0058] The number of installed ejectors 21 may be changed. A plurality of ejectors 21 may be installed in parallel to increase the exhaust force from the tank 20 and the suction force of the material m into the tank 20. Although the exhaust pipe portion 411 of the tank 20 and the ejector 21 are connected via the exhaust hose 412, they may be connected directly without the exhaust hose 412.

[0059] When the start switch is operated to stop the material transfer device 10, if the step is before S112 and material m remains in the tank 20, the operation of the material transfer device 10 may be stopped after proceeding to S117 to discharge material m and empty the tank 20.

[0060] The technical concept is described below. (Technical idea 1) A material transfer device comprising: a container having an exhaust port, a material suction port, and a material discharge port, which stores material sucked in through the material suction port and can discharge the stored material to the outside through the material discharge port; and an exhaust device connected to the exhaust port and exhausting gas within the container, wherein the exhaust device exhausts the gas within the container through the exhaust port to create a negative pressure within the container, and the material is sucked into the container through the material suction port, and the exhaust device is installed integrally with the container.

[0061] (Technical Concept 2) The material transfer device according to Technical Concept 1, wherein the exhaust device is installed integrally with the container via a mounting frame fixed to the container. (Technical Concept 3) The material transfer device of Technical Concept 1, which has a material filtration filter between the exhaust port and the material suction port inside the container.

[0062] (Technical Concept 4) A material transfer device according to Technical Concept 3, wherein the container has an air intake port on the exhaust port side of the material filtration filter, and the air intake port is connected to an air supply device. (Technical Concept 5) A method for cleaning a material filter of a material transfer device using the material transfer device of Technical Concept 4, comprising: a suction process in which the exhaust device exhausts gas from within the container through the exhaust port to create a negative pressure within the container, and then sucks the material into the container through the material suction port; and a cleaning process in which, after the suction process, the air supply device supplies gas from the air supply port into the container, and removes the material adhering to the material filter. [Explanation of symbols]

[0063] 10...Material transfer device 20...Tank (container) 21...Ejector (exhaust device) 24...Compressor (air supply device) 30...Tank body 33...Discharge part (material discharge port) 40...Tank cover 50...Filter unit 53...Filter (material filtration filter) 311...Suction cylinder part (material suction port) 313...Ejector mounting frame (mounting frame) 411...Exhaust pipe section (exhaust port) 413...Air intake section (air intake port) a...Air ca...Compressed air m...Material.

Claims

1. a container having an exhaust port, a material suction port, and a material discharge port, which stores the material sucked through the material suction port and can discharge the stored material to the outside through the material discharge port; an exhaust device connected to the exhaust port and configured to exhaust gas from the container; a material transfer device that uses the exhaust device to exhaust gas from the container through the exhaust port to create a negative pressure inside the container, and then sucks the material into the container through the material suction port, Fixing the exhaust device to the container, and locating the exhaust device integrally with the container; the exhaust device is an ejector, the material transfer device further includes an air supply device that generates and supplies compressed air, and an electromagnetic valve that supplies and stops the supply of the compressed air to the ejector; The solenoid valve is fixed to the container, and the solenoid valve is integrally installed with the container; the container comprises a filter unit; the filter unit includes a material filter, two reinforcing plates sandwiching the material filter from both sides, and a filter frame surrounding end faces and outer peripheral edges of the two reinforcing plates sandwiching the material filter, The material transfer device, wherein the filter unit is positioned between the exhaust port and the material suction port within the container.

2. The container further includes a tank body and a tank cover, The tank body has a filter receiving portion including an annular receiving plate and a cylindrical inner wall extending upward from an outer edge of the receiving plate, the tank cover has a filter pressing portion including an annular pressing plate and a cylindrical outer wall extending downward from an outer edge of the pressing plate, The filter holding portion can fit onto the filter receiving portion, The material transfer device according to claim 1 , wherein the filter unit is located between the filter presser and the filter receiver.

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