Mold falling prevention device

Abstract

[Problem] The objective of the present invention is to provide a mold falling prevention device that, by being provided with a detection device that detects when hooks are actually coupled to a mold, prevents the human error of forgetting to connect the hooks. [Solution] A mold falling prevention device according to the present invention is for ensuring that hooks 14 provided to platens 8, 9 of a horizontal injection molding machine are connected to a mold M that is detachably attached to the platens 8, 9, thereby preventing the mold M from falling. The mold falling prevention device is provided with a detection device 15 to detect that the hooks 14 are connected to the mold M.

Description

Mold fall prevention device

[0001] The present invention relates to a mold drop prevention device for a horizontal injection molding machine.

[0002] Examples of mold drop prevention devices for horizontal injection molding machines are described in Utility Model Registration No. 3136001 (Patent Document 1) and Japanese Patent Laid-Open No. 2022-44515 (Patent Document 2).

[0003] In this conventional horizontal injection molding machine, a fixed platen and a movable platen are arranged facing each other so that they can move relative to each other in the horizontal direction. A fixed-side magnet plate and a movable-side magnet plate of an electromagnetic attraction device are fixed to the opposing end faces of the platens.

[0004] To attach a mold to the magnetic plates, the mold suspended from the hook of an overhead traveling crane is inserted from above into the space between the fixed and movable platens. After the mold is fixed by suction to both magnetic plates, the worker releases the engagement between the crane hook and the mold eyebolt.

[0005] A mold fall prevention device is provided on the top surface of the magnet plate. The mold fall prevention device consists of a chain fixed to the platen side with a hook at the end. By engaging this hook with the eyebolt of the mold, the mold is prevented from falling off the magnet plate.

[0006] Since the above-mentioned mold mounting work was performed manually by an operator, there was a risk of human error such as forgetting to connect the hook of the mold fall prevention device to the eyebolt of the mold, which could result in an accidental mold fall.

[0007] Therefore, a detection device is provided to detect whether the hook of the die fall prevention device has been left unconnected to the eyebolt of the die.

[0008] The conventional detection device includes a safety plug attached to the hook of the mold fall prevention device, a socket attached to the magnetic plate to detachably connect the safety plug, and a detection means for detecting the connection state of the safety plug and the socket. When the safety plug is connected to the socket, the detection means notifies the operator that the hook of the mold fall prevention device is not coupled to the mold, and when the connection between the safety plug and the socket is released, the detection means notifies the operator that the hook is coupled to the mold.

[0009] The reason why the socket is provided on the magnetic plate is that before the mold is mounted on the horizontal injection molding machine, if the hook of the mold fall prevention device is located on the mold mounting surface of the platen, it will interfere with the mold mounting, so the hook is placed on the top surface of the platen and the safety plug is connected to the socket and stored there. Then, after the mold is mounted on the platen, the safety plug attached to the hook is removed from the socket, the hook on the top surface of the platen is moved above the mold, and the hook is connected to the eyebolt of the mold.

[0010] Utility Model Registration No. 3136001 JP 2022-44515 A

[0011] The conventional detection device notifies the operator that the hook of the mold fall prevention device is connected to the mold, even if the hook and the mold are not actually connected, as long as the connection between the safety plug and the socket is released.

[0012] Therefore, even if the worker disconnects the safety plug and socket during the mold installation work but forgets to connect the hook of the mold fall prevention device to the mold, the device notifies the operator that the hook is connected to the mold.

[0013] In other words, the conventional device only notifies the user that the hook is connected to the mold when the safety plug and socket are released from each other, but does not actually detect that the hook is connected to the mold.

[0014] Therefore, the present invention aims to provide a mold drop prevention device that prevents human error such as forgetting to connect the hook by providing a detection device that detects when the hook has actually been connected to the mold.

[0015] In order to achieve the above object, the present invention provides the following means: The mold fall prevention device of the present invention prevents a mold detachably attached to a platen of a horizontal injection molding machine by connecting a hook provided on the platen to the mold, and is provided with a detection device that detects when the hook has been connected to the mold.

[0016] It is preferable that the detection device has an engaging portion provided on the hook, an engaged portion provided on the mold and capable of engaging and disengaging with the engaging portion, and a control device that detects the connection between the engaging portion and the engaged portion.

[0017] The engaged portion and the control device are preferably connected via a cable in a detachable manner.

[0018] It is preferable that the platen has a magnetic plate for detachably fixing the mold, and that the hook is provided on the magnetic plate.

[0019] The detection device may be configured with an image processing device that identifies whether the hook is connected to the mold.

[0020] According to the present invention, a detection device is provided that detects the connection when the hook of the mold fall prevention device is connected to the mold, thereby preventing human error such as forgetting to connect as in the conventional case.

[0021] Fig. 1 is a diagram showing the process of mounting a mold on a horizontal injection molding machine. Fig. 2 is an explanatory diagram of a mold fall prevention device. Fig. 3 is a perspective view of the mold fall prevention device. Fig. 4 is a front view of Fig. 3. Fig. 5 is a perspective view of a detection device with an engaging portion (plug) provided on the hook of the mold fall prevention device. Fig. 6 is a perspective view of an engaged portion (socket) attached to the upper surface of the mold. Fig. 7 is an explanatory diagram in which the engaging portion and engaged portion are composed of a safety plug. Fig. 8 is an explanatory diagram in which the engaging portion and engaged portion are composed of a proximity switch.

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0023] FIG. 1 is a process diagram for mounting a mold on a horizontal injection molding machine, where FIG. 1(a) shows the initial stage of the mold mounting operation and FIG. 1(b) shows the final stage.

[0024] FIG. 2 is an explanatory diagram of the die drop prevention device, and is a cross-sectional view taken along line AA in FIG. 1 as viewed from the left to right, with the die M shown in imaginary lines.

[0025] The horizontal injection molding machine has a clamping section 2 and an injection section 3 mounted on a machine base 1 installed on the floor. The injection section 3 is provided with a hopper 4 for inserting resin raw material and a nozzle unit 5 for injecting molten resin.

[0026] The mold clamping unit 2 is covered by a fixed cover 6 and an openable / closable safety door 7, and a fixed platen 8 and a movable platen 9 are disposed facing each other and are relatively movable in the horizontal direction (left and right direction in FIG. 1 ). The safety door 7 slides rightward along a guide rail 10 from the state in FIG. 1 to openably and closably cover the opposing space between the platens 8 and 9.

[0027] The fixed platen 8 is fixed to four tie bars 11, and the movable platen 9 is slidably guided by the tie bars 11. The mold clamping unit 2 is provided with a drive unit that moves the movable platen 9 toward the fixed platen 8, but this is not visible in the drawing as it is covered by the fixed cover 6 and the safety door 7. The nozzle unit 5 of the injection unit 3 is inserted into the fixed platen 8 (see FIG. 2).

[0028] A mold M suspended by a hook F of a suspension device is inserted from above into the opposing space between the fixed platen 8 and the movable platen 9, and the mold M is attached to the fixed platen 8 and the movable platen 9. The suspension device is usually an overhead traveling crane, and the mold M is suspended by the hook F of the crane.

[0029] The die M is provided with a hanging eyebolt 12 at its center of gravity, and the fixed and movable dies are each provided with a drop prevention eyebolt 13.

[0030] The fall prevention eyebolt 13 is hooked onto a hook 14 (see FIG. 2) of a die fall prevention device provided on the platens 8 and 9, thereby preventing the die M from falling from the platens 8 and 9.

[0031] That is, a mold fall prevention device is provided to prevent the mold M attached to the fixed platen 8 and the movable platen 9 from falling.

[0032] As shown in FIG. 2, the die fall prevention device is provided with a detection device 15 that detects that the hook 14 is connected to the die M.

[0033] In this embodiment, the fixed and movable platens 8, 9 are provided with a fixed-side magnet plate 16 and a movable-side magnet plate 17 of an electromagnetic attraction device on their opposing end faces. However, the present invention can also be applied to a system that does not include the magnet plates 16, 17, and in which the mold M is attached to the platens 8, 9 by a hand clamp or other mechanical clamp.

[0034] 2, the mold M is attracted and fixed to the mold mounting surfaces of the magnet plates 16 and 17. Hooks 14 are provided on the magnet plates 16 and 17 to prevent the fixed mold M from accidentally falling off the platens 8 and 9.

[0035] 3 to 6, the hook 14 is attached to a chain 18, and the chain 18 is fastened to a block 19 attached with bolts to the top surfaces of the magnet plates 16 and 17. The chain 18 is fastened to the block 19 so that its length can be adjusted according to the size of the mold M to be installed.

[0036] The detection device 15 has an engaging portion 20 provided on the hook 14, an engaged portion 21 provided on the mold M and capable of freely engaging and disengaging with the engaging portion 20, and a control device 22 that detects the connection between the engaging portion 20 and the engaged portion 21. The control device 22 detects the connection between the engaging portion 20 and the engaged portion 21 and can notify the operator that the hook 14 is engaged with the mold M.

[0037] The engaging portion 20 is connected to the vicinity of the connection portion between the chain 18 and the hook 14 via a wire 23 (see FIG. 5). The engaged portion 21 is provided on a bracket 24 that is attached to the upper surface of the mold M with a bolt. An electric cable 25 extends from the engaged portion 21 (see FIG. 6). The control device 22 is connected to the electric cable 25 that extends from the engaged portion 21 (see FIG. 2).

[0038] As shown in FIG. 7, the engaging portion 20 and the engaged portion 21 are configured by a plug 20a and a socket 21a, which are so-called "safety plug or short plug."

[0039] As an example of a "safety plug," socket 21a has two sockets inside, and plug 20a has pins that fit into the two sockets, with each pin conducting inside plug 20a. When plug 20a and socket 21a, which are separated as shown in Fig. 7(a), are connected as shown in Fig. 7(b), the socket and pin come into contact and short-circuit (conductivity), and the signal is transmitted to control device 22 via electric cable 25. Note that the specific configuration of the "safety plug" is not limited to that described above.

[0040] 2, the horizontal injection molding machine is provided with a relay box 26. A relay cable 27 extends from this relay box 26, and an end of the relay cable 27 and an end of the electric cable 25 extending from the socket 21a are detachably connected via a connector 28. An end of the relay cable 27 extends from the relay box 26, and the control device 22 is connected to this relay cable 27.

[0041] The control device 22 is composed of a mag clamp control panel 29 connected to a relay cable 27, and a mag clamp operation panel 30 and a molding machine control panel 31 connected via cables from this control panel 29. In addition, a movable side mag clamp wiring 29a, a fixed side mag clamp wiring 29b, and a primary power supply wiring 29c are each connected to the mag clamp control panel 29.

[0042] The operation of the above embodiment will now be described.

[0043] 1, a mold M suspended by a hook F of a suspension device is inserted from above into the opposing space between the fixed platen 8 and the movable platen 9, and the mold M is fixed to the magnet plates 16, 17 of the fixed platen 8 and the movable platen 9, respectively. The hook F is disengaged from the mold M, and the suspension device moves to the standby position. At this time, the hook 14 of the mold fall prevention device is placed on the upper surfaces of the platens 8, 9 in a position that does not interfere with the installation of the mold M.

[0044] 2, the worker connects the end of the electric cable 25 extending from the socket 21a, which is the engaged portion 21 of the detection device 15, to the end of the relay cable 27 via the connector 28. The hook 14 is hooked onto the fall prevention eyebolt 13 on the top surface of the mold M. Then, the plug 20a, which is the engaging portion 20 of the detection device 15, is connected to the socket 21a, which is the engaged portion 21 provided on the top surface of the mold M.

[0045] The length of the wire 23 and the mounting position of the engaged part 21 on the top surface of the mold are set so that the engaging part 20 and the engaged part 21 can be connected when the hook 14 is hooked onto the fall prevention eyebolt 13 on the top surface of the mold M.

[0046] When the operation of attracting the mold M to the magnet plates 16, 17 is completed, a completion signal is input to the mag clamp control panel 29. Then, the clamp ON completion lamp on the mag clamp operation panel 30 is turned on.

[0047] In the detection device 15, when the plug 20a is connected to the socket 21a, a connection signal is input to the mag clamp control panel 29 via cables 25, 27. This connection signal and the completion signal cause an operable signal to be output to the molding machine control panel 31, enabling production by the horizontal injection molding machine. The molding machine control panel 31 is provided with a lamp that indicates that the hook 14 is connected to the mold M, and the lamp can be turned on to notify the operator.

[0048] When manually fastening the mold to the platen without using a magnetic clamp, since there is no magnetic clamp control device, the plug and socket connection signal is directly input into the molding machine control panel and added to the operable conditions.

[0049] Figure 8 shows another embodiment, in which, as shown in Figure 8(a), the engaging portion 20 is composed of a dog 20b connected to a wire 23, and the engaged portion 21 is composed of a proximity switch 21b provided on a bracket 24.

[0050] As shown in FIG. 8(b), by attaching the dog 20b of the engaging portion 20 to the proximity switch 21b of the engaged portion 21, a connection signal is output to the electric cable 25 extending from the proximity switch 21b.

[0051] Instead of the proximity switch, a limit switch or other switch may be used.

[0052] According to the above embodiment, when the hook 14 of the die fall prevention device is connected to the die M, a detection device 15 is provided to detect the connection, thereby preventing human error such as forgetting to connect as in the conventional case.

[0053] The present invention is not limited to the above-described embodiment. For example, the detection device may be configured with an image processing device that identifies whether the hook is connected to the mold. The image processing device may identify the connection between the hook and the mold and turn on a lamp on the molding machine control panel.

[0054] The scope of the present invention is defined by the claims, not by the above description, and includes all modifications within the meaning and scope of the claims.

[0055] REFERENCE SIGNS LIST 1 machine base 2 mold clamping section 3 injection section 4 hopper 5 nozzle unit 6 fixed cover 7 safety door 8 fixed platen 9 movable platen 10 guide rail 11 tie bar 12 hanging eyebolt 13 fall prevention eyebolt 14 hook 15 detection device 16 fixed side magnet plate 17 movable side magnet plate 18 chain 19 block 20 engaging section (20a plug, 20b dog) 21 engaged section (21a socket, 21b proximity switch) 22 control device 23 wire 24 bracket 25 electric cable 26 relay box 27 relay cable 28 connector 29 mag clamp control panel 29a movable side mag clamp wiring 29b fixed side mag clamp wiring 29c primary power supply wiring 30 mag clamp operation panel 31 Molding machine control panel

Claims

1. A mold fall prevention device that prevents a mold from falling by connecting a hook provided on a platen of a horizontal injection molding machine to the mold that is detachably attached to the platen, and that is equipped with a detection device that detects when the hook is connected to the mold.

2. A mold fall prevention device as described in claim 1, wherein the detection device has an engaging portion provided on the hook, an engaged portion provided on the mold that engages freely with the engaging portion, and a control device that detects the connection between the engaging portion and the engaged portion.

3. A die drop prevention device according to claim 2, wherein the engaged portion and the control device are connected via a cable in a manner that allows them to be freely separated.

4. A die drop prevention device according to claim 3, wherein the platen has a magnetic plate for detachably fixing the die, and the hook is provided on the magnetic plate.

5. A die fall prevention device according to claim 1, wherein said detection device is comprised of an image processing device that identifies whether said hook is connected to said die.

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