Safety device used for safety gate of injection molding machine or the like

Abstract

To provide a safety device used for a safety gate of an injection molding machine or the like, which can prevent the safety gate from being undesirably brought into a "fully open state" with a higher probability.SOLUTION: A safety device 100 includes: a stopper 102 protruding from an inside of a safety gate 50; a protector plate 104 that is fixed inside the safety gate 50 and has a notch 114 through which the stopper 102 can pass; and an open / close plate 106 that opens and closes the notch 114. The open / close plate 106 is pivotally supported above the notch 114 so that it can rotate relative to the protector plate 104, and in a natural state, it is in a position where it closes the notch by its own weight.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a safety device used in a safety door that is provided at the front of an injection molding machine or a die-casting machine (hereinafter referred to as "injection molding machine, etc.") and opens and closes in the reciprocating direction of a movable platen. [Background technology]

[0002] Conventionally, safety doors have been provided to allow access to molds when performing work such as replacing molds in injection molding machines and the like.

[0003] In addition, this safety door can be switched between an "open state," which opens only the minimum amount of space to allow access to the mold, and a "fully open state," which allows access to part of the toggle mechanism located at the back of the movable platen.Normally, the door can only be opened to the "open state," but a safety device was installed that allows it to be opened to the "fully open state" by performing an additional operation.

[0004] An example of a safety device for a safety door is disclosed in Patent Document 1. In the safety device according to Patent Document 1, a stopper is provided on the inside of the safety door, and a bracket is provided on the movable platen.

[0005] The bracket has a notch through which the stopper passes when the safety door is moved from the "open position" to the "fully open position," and a stop plate that opens and closes this notch can slide along the bracket.

[0006] Normally, a stop plate is placed in a position that closes the notch, so that even if you try to move the safety door to the "fully open position," the stopper hits the stop plate and cannot pass through the notch, preventing the safety door from being undesirably moved to the "fully open position."

[0007] When moving the safety door to the "fully open state," the stopper plate is moved toward the movable platen, releasing the state in which the stopper has closed the notch. This allows the stopper to pass through the notch, allowing the safety door to be moved to the "fully open state."

[0008] Furthermore, the safety device according to Patent Document 1 has a limit switch that is activated when the stop plate moves completely toward the movable platen, and for safety reasons, the injection molding machine, etc. will not operate while the stop plate is in contact with this limit switch. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-205685 Summary of the Invention [Problem to be solved by the invention]

[0010] However, in the safety device of Patent Document 1, the stop plate is designed to slide horizontally relative to the bracket, so if the stop plate is accidentally moved toward the movable platen to an extent that does not activate the limit switch, there is a risk that the safety door will be in a "fully open state" while the injection molding machine or the like is able to operate.

[0011] Similarly, if the limit switch malfunctions, there is a risk that the safety door will be in a "fully open" state while the injection molding machine or other device is still operational.

[0012] The present invention has been made in view of such problems, and its purpose is to provide a safety device to be used in a safety door of an injection molding machine or the like, which can more likely prevent the safety door from being in an undesired "fully open state." [Means for solving the problem]

[0013] According to one aspect of the present invention, a stopper protruding from the inside of the safety door; a protector plate having a notch through which the stopper can pass and fixed inside the safety door; an opening and closing plate that opens and closes the notch, The opening and closing plate is pivotally supported on the protector plate above the notch, and is in a position where it closes the notch under its own weight in a natural state. A safety device for use in a safety door of an injection molding machine or the like is provided.

[0014] Preferably, The opening and closing plate has a long hole extending in the vertical direction in a natural state, The protector plate is provided with a rotation shaft and an open state retention shaft insertion hole through which an open state retention shaft is inserted in a lateral direction of the rotation shaft, The pivot shaft is inserted into the long hole, so that the open-close plate can pivot relative to the protector plate. The distance between the rotation shaft and the open state retention shaft insertion hole is In a natural state, the distance is equal to or shorter than the longest distance W2 between the pivot shaft and the lower edge of the opening and closing plate when the pivot shaft is at the upper end of the long hole in the opening and closing plate, In a natural state, the distance is equal to or longer than the maximum distance W3 between the pivot shaft and the lower edge of the opening and closing plate when the pivot shaft is at the lower end of the long hole in the opening and closing plate.

[0015] Preferably, The opening and closing plate has a long hole extending in the vertical direction in a natural state, A rotation shaft and an open state holding shaft are protruded from the protector plate in a lateral direction of the rotation shaft, The pivot shaft is inserted into the long hole, so that the open-close plate can pivot relative to the protector plate. The distance between the rotation axis and the open state holding axis is In a natural state, the distance W2 is shorter than the longest distance W2 between the pivot shaft and the lower edge of the opening and closing plate when the pivot shaft is at the upper end of the long hole in the opening and closing plate, In a natural state, this is longer than the maximum distance W3 between the pivot shaft and the lower edge of the opening and closing plate when the pivot shaft is at the lower end of the long hole in the opening and closing plate.

[0016] Preferably, A locking shaft projects from the protector plate, In a natural state, the locking shaft is locked to the lower edge of the opening and closing plate when the rotation shaft is at the upper end of the elongated hole in the opening and closing plate. [Effects of the Invention]

[0017] In the safety device according to the present invention used in a safety door of an injection molding machine or the like, the opening / closing plate that opens and closes a notch formed in the protector plate is rotatably supported on the protector plate above the notch, and in its natural state is in a position where it closes the notch under its own weight.

[0018] As a result, simply by releasing the opening / closing plate and letting it rest in its natural position, the opening / closing plate will always be positioned to close the notch in the protector plate by its own weight, thereby providing a safety device for use with safety doors of injection molding machines, etc., which can more likely avoid the risk of the safety door becoming undesirably in a "fully open state." [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram showing an example of an injection molding machine 10 to which a safety device 100 according to an embodiment is applied. [Figure 2] 1 is a diagram showing an injection molding machine 10 to which a safety door 50 and a fixed cover 52 are attached (safety door 50 in a closed state). [Figure 3]1 is a diagram showing an injection molding machine 10 to which a safety door 50 and a fixed cover 52 are attached (safety door 50 in an open state). [Figure 4] 1 is a diagram showing an injection molding machine 10 to which a safety door 50 and a fixed cover 52 are attached (safety door 50 is fully open). [Figure 5] 1 is a diagram showing an example of a safety device 100 according to an embodiment (with a notch 114 closed). [Figure 6] 1 is a diagram showing an example of a safety device 100 according to an embodiment (with a notch 114 opened). [Figure 7] FIG. 10 is a diagram illustrating distances W1, W2, and W3. [Figure 8] 10 is a diagram showing an example of a safety device 100 according to a first modified example (in a state where a notch 114 is closed). FIG. [Figure 9] 1 is a diagram showing an example of a safety device 100 according to a first modified example (with a notch 114 opened). FIG. [Figure 10] 10 is a diagram illustrating distances W1, W2, and W3 in Modification 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] (Configuration of injection molding machine 10 to which safety device 100 of safety door 50 is applied) The injection molding machine 10 to which the safety device 100 of the safety door 50 according to this embodiment is applied is a machine that manufactures molded products by repeating a molding cycle including mold closing, mold clamping, injecting and filling with molten resin, measuring, mold opening, and removing the molded product, and as shown in FIG. 1, roughly comprises a mold clamping device 12, an injection device 14, and a control device 15.

[0021] The mold clamping device 12 includes a machine base 16 , a fixed platen 18 , a movable platen 20 , a pressure receiving platen 22 , tie bars 24 , a toggle mechanism 26 , and a mold clamping force sensor 27 .

[0022] The machine base 16 is a member that serves as a base for the other members that make up the mold clamping device 12 and the injection device 14.

[0023] The fixed platen 18 is fixed on the machine base 16, and a fixed mold 30 that constitutes a mold 28 is attached to it.

[0024] The movable platen 20 is a member that slides on the machine base 16 so as to approach and move away from the fixed platen 18, and has a movable die 33 attached thereto that constitutes the mold 28. When the movable die 33 comes into contact with the fixed die 30, a cavity is formed that is filled with molten resin.

[0025] The pressure receiving platen 22 is a member fixed on the machine base 16 on the opposite side of the fixed platen 18 as viewed from the movable platen 20 .

[0026] The tie bars 24 are round bar-shaped members having one end fixed to the fixed platen 18 and the other end fixed to the pressure receiving platen 22. The tie bars 24 are inserted into tie bar insertion holes 31 formed in the movable platen 20 arranged between the fixed platen 18 and the pressure receiving platen 22. This allows the movable platen 20 to slide along the tie bars 24 on the machine base 16 in the left-right direction in the drawing. A plurality of tie bars 24 (for example, four) are used.

[0027] The toggle mechanism 26 is a mechanism for moving the movable platen 20 toward or away from the fixed platen 18 , and the mold clamping drive device 32 is attached to the pressure receiving platen 22 .

[0028] The movable platen 20 moves along the tie bars 24 (moving left and right in the drawing) as the driving force of the mold clamping drive device 32 is transmitted through the toggle mechanism 26. When the movable platen 20 moves leftward, the fixed mold 30 and the movable mold 33 move apart. On the other hand, when the movable platen 20 moves rightward, the fixed mold 30 and the movable mold 33 come into contact with each other, forming a cavity (internal space) inside the mold 28. Then, when pressure is further applied in a direction that moves the movable platen 20 rightward, the fixed mold 30 and the movable mold 33 are clamped.

[0029] The mold clamping force sensor 27 is a sensor that measures the mold clamping force of the movable mold 33 relative to the fixed mold 30, and is attached to at least one tie bar 24. Specifically, the distortion of the tie bar 24 during mold clamping is measured, and the control device 15 calculates the mold clamping force based on the amount of distortion. The attachment position of the mold clamping force sensor 27 is not particularly limited.

[0030] The injection device 14 is a device that injects and fills molten resin into a mold (cavity) 28 that is formed when the movable mold 33 comes into contact with the fixed mold 30, and has a heating cylinder 44 around which a heater is arranged, and an injection nozzle 46 whose tip comes into contact with the mold 28. A screw 48 that sends molten resin to the injection nozzle 46 is housed inside the heating cylinder 44.

[0031] The control device 15 is a device that controls the entire molding cycle performed by the injection molding machine 10.

[0032] (Configuration of the safety door 50 and the safety device 100) The injection molding machine 10 described above is usually provided with a safety door 50 as shown in FIG. 2 to prevent accidental contact with the movable platen 20, toggle mechanism 26, etc. while in operation.

[0033] This safety door 50 slides in the direction of movement of the movable platen 20. In this embodiment, when the safety door 50 is slid to the left in the figure, the safety door 50 moves so that it overlaps with the fixed cover 52, and enters an "open state" in which the fixed mold 30 and the movable mold 33 can be directly touched (see Figure 3).

[0034] When the safety door 50 is further slid leftward in the drawing from this "open state," it reaches a "fully open state" in which the end of the toggle mechanism 26 on the movable platen 20 side can be directly touched (see FIG. 4).

[0035] In this way, when the safety door 50 is in the "fully open state," it becomes possible to directly touch the toggle mechanism 26, which is more dangerous during operation. Therefore, the injection molding machine 10 according to this embodiment is provided with a safety device 100 to prevent the safety door 50 from being undesirably placed in the "fully open state."

[0036] As shown in FIGS. 5 and 6, the safety device 100 includes a stopper 102, a protector plate 104, an opening / closing plate 106, a rotating shaft 108, an open state maintaining shaft insertion hole 111, and a locking shaft 112.

[0037] The stopper 102 is a member that protrudes from the inside of the safety door 50, and in this embodiment is formed in a substantially rectangular shape, but the shape of the stopper 102 is not particularly limited.

[0038] The protector plate 104 is a plate-shaped member fixed inside the safety door 50 (in this embodiment, to the movable platen 20), and has a notch 114 formed therein through which the stopper 102 can pass when the safety door 50 is opened or closed.

[0039] The opening / closing plate 106 is a plate member for opening and closing the notch 114 formed in the protector plate 104, and has a main body member 116, an elongated hole 118, a locking recess 120, and a handle 122. The opening / closing plate 106 is pivotally supported on the protector plate 104 above the notch 114, and in its natural state is in a position where it closes the notch 114 under its own weight.

[0040] The elongated hole 118 is a hole through which the rotating shaft 108 is inserted, and is formed so as to extend in the vertical direction when the opening-closing plate 106 is in its natural state (i.e., when it is in a position where it closes the notch 114 due to its own weight). In other words, the rotating shaft 108 is able to slide along this elongated hole 118.

[0041] The locking recess 120 is a recess that locks with the locking shaft 112 when the opening / closing plate 106 is in its natural state (i.e., when it is in a position where it closes the notch 114 due to its own weight), and is formed on the lower edge of the opening / closing plate 106 in its natural state.

[0042] The handle 122 is a part that can be used as a handle when rotating the opening / closing plate 106 around the rotation shaft 108 .

[0043] The rotation shaft 108 is a member that protrudes from the protector plate 104, and is inserted into the elongated hole 118 of the opening and closing plate 106 as described above.

[0044] The open state retention shaft insertion hole 111 is a hole provided in the protector plate 104 in an approximately horizontal direction when viewed from the pivot shaft 108, and the open state retention shaft 110 (pin, etc.) attached to this open state retention shaft insertion hole 111 is engaged with the engagement recess 120 of the opening / closing plate 106 which has been rotated approximately 90° around the pivot shaft 108, thereby maintaining the notch 114 in an open state.

[0045] Also, as shown in Figure 7, the distance W1 between the pivot shaft 108 and the open state retaining shaft 110 (open state retaining shaft insertion hole 111) is set to be the same as or shorter than the longest distance W2 between the pivot shaft 108 and the lower edge of the opening and closing plate 106 (in this embodiment, the locking recess 120) when the pivot shaft 108 is at the upper end of the long hole 118 in the opening and closing plate 106 in the natural state, and to be the same as or longer than the longest distance W3 between the pivot shaft 108 and the lower edge of the opening and closing plate 106 (in this embodiment, the locking recess 120) when the pivot shaft 108 is at the lower end of the long hole 118 in the opening and closing plate 106 in the natural state.

[0046] As a result, even if the opening-closing plate 106 is rotated by mistake when the rotation shaft 108 is at the upper end of the elongated hole 118 in the natural state of the opening-closing plate 106 (i.e., when the opening-closing plate 106 is hanging from the rotation shaft 108 by its own weight), the opening-closing plate 106 will return to its original position by its own weight unless the locking recess 120 of the opening-closing plate 106 is engaged with the open state retention shaft 110, and the notch 114 of the protector plate 104 can be maintained in a closed state. The same applies when the open state retention shaft 110 (pin, etc.) is removed from the open state retention shaft insertion hole 111.

[0047] When intentionally moving from the "open state" to the "fully open state," the opening-closing plate 106 is raised vertically upward to move the rotation shaft 108 toward the lower end of the elongated hole 118, and then the opening-closing plate 106 is rotated. In this state, the maximum distance W3 between the rotation shaft 108 and the lower edge of the opening-closing plate 106 (the locking recess 120 in this embodiment) is shorter than the distance W1 between the rotation shaft 108 and the open state maintaining shaft 110, so the locking recess 120 of the opening-closing plate 106 can be engaged with the open state maintaining shaft 110. This allows the notch 114 of the protector plate 104 to be maintained in an open state, and the stopper 102 can be passed through the notch 114 to set the safety door 50 to the "fully open state."

[0048] The locking shaft 112 is a member that protrudes from the protector plate 104 in a direction approximately vertically downward when viewed from the pivot shaft 108, and is designed to engage and hold with the locking recess 120 of the opening / closing plate 106 when the opening / closing plate 106 is hanging from the pivot shaft 108 by its own weight.

[0049] In this way, by engaging the locking recess 120 of the opening / closing plate 106 with the locking shaft 112, it is possible to prevent the opening / closing plate 106 from rotating undesirably with the notch 114 closed.

[0050] In the safety device 100 according to this embodiment, which is used in the safety door 50 of the injection molding machine 10, the opening / closing plate 106 that opens and closes the notch 114 formed in the protector plate 104 is rotatably supported on the protector plate 104 above the notch 114, and in its natural state is in a position where it closes the notch 114 under its own weight.

[0051] As a result, simply by releasing the opening / closing plate 106 and letting it rest in its natural state, the opening / closing plate 106 will always be positioned to close the notch 114 of the protector plate 104 by its own weight, so it is possible to provide a safety device 100 used for the safety door 50 of the injection molding machine 10, which can more likely avoid the risk of the safety door 50 becoming undesirably in a "fully open state."

[0052] (Variation 1) In the above-described embodiment, an open state retention shaft insertion hole 111 is provided in the protector plate 104, and an open state retention shaft 110 (such as a pin) is inserted into the open state retention shaft insertion hole 111. However, instead, the open state retention shaft 110 may be protruded from the protector plate 104, as shown in Figures 8 and 9.

[0053] This open state holding shaft 110 is adapted to engage and hold a locking recess 120 of the opening / closing plate 106 when the opening / closing plate 106 is rotated approximately 90° around the rotation shaft 108 to open the notch 114.

[0054] Also, as shown in Figure 10, the distance W1 between the pivot shaft 108 and the open state retention shaft 110 is set to be shorter than the longest distance W2 between the pivot shaft 108 and the lower edge of the opening / closing plate 106 (in this embodiment, the locking recess 120) when the pivot shaft 108 is at the upper end of the long hole 118 in the opening / closing plate 106 in the natural state, and longer than the longest distance W3 between the pivot shaft 108 and the lower edge of the opening / closing plate 106 (in this embodiment, the locking recess 120) when the pivot shaft 108 is at the lower end of the long hole 118 in the opening / closing plate 106 in the natural state.

[0055] As a result, even if the opening and closing plate 106 is accidentally rotated when the pivot shaft 108 is at the upper end of the long hole 118 in the natural state of the opening and closing plate 106 (i.e., when the opening and closing plate 106 is hanging from the pivot shaft 108 due to its own weight), the longest distance W2 between the pivot shaft 108 and the lower edge of the opening and closing plate 106 (in this embodiment, the locking recess 120) is longer than the distance W1 between the pivot shaft 108 and the open state retention shaft 110, so the locking recess 120 of the opening and closing plate 106 cannot engage with the open state retention shaft 110, and the opening and closing plate 106 returns to its original position due to its own weight, allowing the notch 114 of the protector plate 104 to remain closed.

[0056] Unlike the embodiment, the distance W1 is shorter than W2 and longer than W3 because the open state retention shaft 110 protrudes from the protector plate 104 as described above, and if it is not set in this manner, the opening / closing plate 106 cannot be rotated until the locking recess 120 is at the position of the open state retention shaft 110.

[0057] (Variation 2) In the above-described embodiment, an example has been described in which the safety device 100 used in the safety door 50 is applied to the injection molding machine 10, but this safety device 100 can also be applied to a die-casting machine, etc. Throughout this specification, injection molding machines, die-casting machines, etc. to which the safety device 100 can be applied will be collectively referred to as "injection molding machines, etc."

[0058] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0059] 10... injection molding machine, 12... mold clamping device, 14... injection device, 15... control device, 16... machine base, 18... fixed platen, 20... movable platen, 22... pressure receiving platen, 24... tie bar, 26... toggle mechanism, 27... mold clamping force sensor, 28... mold, 30... fixed mold, 31... tie bar insertion hole, 32... mold clamping drive device, 33... movable mold, 44... heating cylinder, 46... injection nozzle, 48... screw 50...Safety door, 52...Fixed cover 100...safety device, 102...stopper, 104...protector plate, 106...opening / closing plate, 108...rotating shaft, 110...open state retaining shaft, 111...open state retaining shaft insertion hole, 112...locking shaft, 114...notch, 116...main body member (of opening / closing plate 106), 118...long hole, 120...locking recess, 122...handle

Claims

1. a stopper protruding from the inside of the safety door; a protector plate having a notch through which the stopper can pass and fixed inside the safety door; an opening and closing plate that opens and closes the notch, The opening and closing plate is pivotally supported on the protector plate above the notch, and is in a position where it closes the notch under its own weight in a natural state. A safety device used in safety doors of injection molding machines, etc.

2. The opening and closing plate has a long hole extending in the vertical direction in a natural state, The protector plate is provided with a rotation shaft and an open state retention shaft insertion hole through which an open state retention shaft is inserted in a lateral direction of the rotation shaft, The pivot shaft is inserted into the long hole, so that the open-close plate can pivot relative to the protector plate. The distance between the rotation shaft and the open state retention shaft insertion hole is In a natural state, the distance is equal to or shorter than the longest distance W2 between the pivot shaft and the lower edge of the opening and closing plate when the pivot shaft is at the upper end of the long hole in the opening and closing plate, In a natural state, the rotation axis is the same as or longer than the longest distance W3 between the rotation axis and the lower edge of the opening and closing plate when the rotation axis is at the lower end of the long hole in the opening and closing plate.

2. The safety device of claim 1.

3. The opening and closing plate has a long hole extending in the vertical direction in a natural state, A rotation shaft and an open state holding shaft are protruded from the protector plate in a lateral direction of the rotation shaft, The pivot shaft is inserted into the long hole, so that the open-close plate can pivot relative to the protector plate. The distance between the rotation axis and the open state holding axis is In a natural state, the distance W2 is shorter than the longest distance W2 between the pivot shaft and the lower edge of the opening and closing plate when the pivot shaft is at the upper end of the long hole in the opening and closing plate, In a natural state, the distance W3 is longer than the maximum distance W3 between the pivot shaft and the lower edge of the opening and closing plate when the pivot shaft is at the lower end of the long hole in the opening and closing plate.

2. The safety device of claim 1.

4. A locking shaft projects from the protector plate, The locking shaft is locked to the lower edge of the opening and closing plate when the rotation shaft is at the upper end of the long hole in the opening and closing plate in a natural state.

4. A safety device according to claim 2 or 3.

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