JP5300849B2 - Mold contact detection device for injection molding machines - Google Patents

Abstract

Metal mold adherence detectors (30A, 30B) are applicable to an injection molding machine (1) having clamp plates (10A, 10B) each of which includes a fixing surface (12a) for fixing a metal mold M2 and multiple sets of magnetic force generator mechanisms (13) capable of generating the magnetic force for fixing the metal mold. The metal mold adherence detectors (30A, 30B) are provided with electrodes (31a, 32a) which can be adhered to the metal mold M, a resilient member (41) for resiliently biasing the electrodes in the direction of adherence to the metal mold M2, an insulation member (43) for insulating the electrodes, an electrical detection circuit (50) which is configured including the electrodes and the metal mold M2 and is connected with a power supply, and a detection means (65) which has a detection section (61) partly in connection with the electrical detection circuit (50) and detects adherence of the metal mold to the metal mold fixing surface. The presence or absence of adherence of the metal mold M to the metal mold fixing surface can be detected accurately, simply and reliably using the electrical detection circuit configured including the metal mold M.

Description

  The present invention relates to a mold contact detection device for an injection molding machine, and an electric circuit for detection including an electrode and a mold that can be in close contact with a mold when the mold is attracted to a clamp plate fixed to a platen by a magnetic force. It is related with the apparatus which detected the adhesion | attachment of the metal mold | die to a metal mold | die fixed surface.

  Conventionally, in an injection molding machine, a plurality of bolts, a hydraulic clamp device, and the like have been widely adopted as a clamp device for fixing a mold to a fixed side platen and a movable side platen. Recently, a clamp plate incorporating multiple sets of magnetic force generation mechanisms is fixed to the platen, and the mold is attracted to the mold fixing surface (hereinafter referred to as the fixed surface) by the magnetic force generated by the magnetic force generation mechanism. A mold fixing device for fixing by fixing is becoming widespread.

  In each of the magnetic force generation mechanisms, the magnetic path is switched by switching the polarity of the Alnico magnet by energizing the coil on the outer peripheral side, and the operation state in which the mold is attracted to the fixed surface and the mold is not attracted to the fixed surface. Change over the state. In the operating state, if the mold is in close contact with the fixed surface, a sufficient magnetic force (adsorption force) acts on the mold, but if the mold is not in close contact with the fixed surface, it acts on the mold. The magnetic force is significantly reduced, and the mold is displaced from the clamp plate or falls off. For example, the above problem is likely to occur when a foreign object or the like is sandwiched between the fixed surface and the mold, or when the mold is lifted from the fixed surface due to vibration during operation or the like. In that case, there is a risk of damage to the mold, generation of defective molded products, and the like.

  Therefore, various mold contact detection devices that detect the presence or absence of contact with the fixed surface of the mold have been proposed and put into practical use. A typical example is a mold contact detection device having a proximity switch in which a mold fixed to a fixed surface is mounted on a clamp plate so as to be detected. In this mold contact detection device, the proximity switch detects the mold in a non-contact state and is turned on, but the proximity switch is not turned on when the mold is separated from the fixed surface by, for example, 0.2 mm or more. Thus, the non-contact of the mold to the fixed surface can be detected.

On the other hand, in the magnetic clamping device of Patent Document 1, a plurality of magnetic holding units are incorporated in the clamp plate, and a probe coil having a small number of turns is mounted outside the main coil of the magnetic holding unit, and the mold is connected to the fixed surface. When the mold is separated from the fixed surface, a voltage corresponding to a change in magnetic flux is generated by the probe coil, and the adhesion and detachment of the mold from the fixed surface can be detected from this voltage detection value.
JP 2005-515080 A

  In the mold contact detection device having the proximity switch, the proximity switch detects the mold in a non-contact state. There is an error of about 10% in the detection distance of the proximity switch, and the detection distance of the proximity switch also varies depending on the temperature, so that the gap between the fixed surface and the mold is separated by a predetermined distance (for example 0.2 mm) or more. In the state, even if it is configured to detect that the mold is not in close contact with the fixed surface, it is difficult to accurately and reliably detect the close contact of the mold with the fixed surface due to the various error factors described above.

  Moreover, a normal mold is composed of a mold body and a mounting plate, the mold body is fixed to the mounting plate with a plurality of bolts, and the back surface of the mounting plate is fixed to the fixed surface. Therefore, since a plurality of bolt head accommodation holes are opened on the back surface of the mounting plate of the mold, the proximity switch faces the bolt head accommodation hole of the mold when the mold is fixed to the fixing surface. there is a possibility. When the proximity switch faces the bolt head receiving hole, the distance from the proximity switch to the bolt head becomes much larger than the predetermined distance, so that it is erroneously detected that the mold is in contact but not in contact. There is a fear. Thus, it is difficult to obtain desired detection accuracy and reliability in a mold contact detection device using a proximity switch.

On the other hand, in the device that detects the adhesion and detachment of the die by the probe coil of the magnetic clamp device described in Patent Document 1, the change in magnetic flux is detected through the probe coil (about 1 to 10 turns) with a small number of turns. It is difficult to accurately and reliably detect mold adhesion and detachment.
For example, when the moving speed of the mold approaching or separating from the fixed surface is small, the induced electromotive force generated in the probe coil becomes weak and cannot be distinguished from noise, so it is possible to reliably detect the behavior of the mold. Have difficulty.

  An object of the present invention is to provide an injection capable of accurately and easily detecting whether or not a mold is closely attached to a mold fixing surface of a clamp plate by using an electric circuit for detection including the mold. It is providing the metal mold | die contact | adherence detection apparatus of a molding machine.

  A mold contact detection device for an injection molding machine according to claim 1 has a mold fixing surface for fixing a mold and is fixed to a platen surface of the platen, and is fixed to the mold by being incorporated in the clamp plate body. In a mold contact detection device for detecting the contact of a mold to the mold fixing surface in an injection molding machine having a clamp plate having a plurality of sets of magnetic force generation mechanisms capable of generating a magnetic force for the clamp plate body, An electrode mounted on the recessed electrode mounting hole and in contact with the mold in close contact with the mold fixing surface, and elastically biased in a direction in which the electrode is mounted in the electrode mounting hole and in close contact with the mold. At least one of an elastic member, an insulating member for insulating the electrode from the clamp plate body, a detection electric circuit including the electrode and a mold and connected to a power source, and the detection electric circuit There have detectable portion connected, it is characterized in that a detecting means for detecting the contact of the mold to the mold fixing surface through the detection electric circuit.

  In this mold contact detection device, when the mold is not in close contact with the mold fixing surface of the clamp plate, the electrode biased by the elastic member is held in a state of protruding a small amount from the fixing surface. When the mold is in close contact with the mold fixing surface, the electrode is surely in contact with the mold. The electrode is insulated from the clamp plate body by an insulating member, and a detection electric circuit including the electrode and the mold and connected to the power source is provided, and at least a part of the detection electric circuit is connected to the detection electric circuit. The detection means having the detection unit detects the adhesion of the mold to the mold fixing surface via the detection electric circuit.

In addition to the above-described configuration of the present invention, the following various configurations may be employed.
The clamp plate main body is provided with a gap forming means for forming a gap for separation between the tip surface of the electrode and the mold when the mold is not fixed to the mold fixing surface. The forming means includes a receiving hole formed in the clamp plate body, and a movable member that is mounted in the receiving hole and can be switched between a protruding position that protrudes from the mold fixing surface by a minute predetermined length and a non-projecting position that does not protrude. A spring member that is housed in the housing hole and elastically biases the movable member toward the projecting position, and a regulation bolt that restrains the movable member from projecting beyond the projecting position (Claim 2).

The tip of the electrode facing the mold is formed larger than the diameter of the bolt head receiving hole formed in the mounting plate so as to receive the head of the bolt that fixes the mold body to the mounting plate of the mold. (Claim 3).
First and second electrodes are provided at positions spaced apart from each other as the electrodes, and the electric circuit for detection includes a contact portion between the first electrode and the mold and a contact portion between the second electrode and the mold. Item 4).

First and second electrodes are provided at positions spaced apart from each other as the electrodes, and the detection electric circuit includes a first electric circuit including a contact portion between the first electrode and the mold, a second electrode and the mold, A second electric circuit including a second electric circuit connected in parallel with the first electric circuit (Claim 5).
The detection unit includes a light emitting diode connected to a detection electric circuit.

  According to the first aspect of the present invention, when the mold is not in close contact with the mold fixing surface of the clamp plate, the electrode urged by the elastic member protrudes from the fixing surface by a minute amount. When the mold is in close contact with the mold fixing surface, the electrode is surely in contact with the mold. Then, the adhesion of the mold to the mold fixing surface can be reliably detected by the detection means through the detection electric circuit including the electrode and the mold and connected to the power source. Thereby, the adhesion of the mold to the mold fixing surface can be reliably detected. In this way, it is possible to accurately and reliably detect the adhesion of the mold to the mold fixing surface using the detection electric circuit including the electrode and the mold.

  According to a second aspect of the present invention, when the mold is not fixed to the mold fixing surface in the clamp plate body, a separation gap is formed between the tip surface of the electrode and the mold. A gap forming means that includes a receiving hole formed in the clamp plate body, a movable member that can be switched between a projecting position and a non-projecting position, a spring member that elastically biases the movable member, Since the movable member has a restriction bolt that restricts the movable member so that it does not protrude beyond the protruding position, a gap is left in a state where the mold is opposed to the mold fixing surface and the mold is not fixed to the mold fixing surface. A separation gap is formed between the tip surface of the electrode and the mold by the forming means.

  Therefore, when the mold is replaced, it is possible to reliably prevent erroneous detection that the mold is in close contact with the mold fixing surface only by contacting the electrode that is close to and facing the mold fixing surface. it can. Also, when releasing the mold by the magnetic force generation mechanism, a gap is formed between the tip surface of the electrode and the mold by the gap forming means in the same manner as described above, and the mold is reliably separated from the electrode. Therefore, it is possible to reliably detect the unlocking of the mold.

  According to the invention of claim 3, the bolt head housing formed in the mounting plate so as to receive the electrode tip facing the mold and the bolt head for fixing the mold body to the mounting plate of the mold. Since it is formed larger than the diameter of the hole, even when the tip of the electrode faces the bolt head receiving hole when the die is in close contact with the die fixing surface, the tip of the electrode can be reliably brought into contact with the die. .

  According to a fourth aspect of the present invention, the first and second electrodes are provided at positions spaced apart from each other as electrodes, and the detection electric circuit includes a contact member between the first electrode and the mold, and a second electrode and the mold. Therefore, when both the first and second electrodes are in contact with the mold, it can be detected that the mold is in close contact with the mold fixing surface. By disposing the first and second electrodes at spaced positions, it is possible to detect whether the entire surface of the mold is in close contact with the mold fixing surface. For example, even when a small foreign object is caught between the mold and the mold fixing surface, the adhesion failure can be reliably detected.

  According to the invention of claim 5, the first and second electrodes are provided at positions separated from each other as electrodes, and the detection electric circuit includes a first electric circuit including a contact portion between the first electrode and the mold, Since the second electric circuit including the contact portion between the second electrode and the mold and provided in parallel with the first electric circuit is provided, the entire surface of the mold is the same as in the fourth aspect. It is possible to reliably detect whether or not the mold fixing surface is in close contact.

  According to the invention of claim 6, since the detection part of the detection means has the light emitting diode connected to the electric circuit for detection, the photo fixed to the mold fixing surface via the photorelay including the light emitting diode and the control unit. It is possible to make it possible to detect the close contact of the metal mold, or to emit light from the light emitting diode to the outside so that the close contact of the metal mold to the fixed surface of the metal mold can be detected.

It is a front view of the principal part and metal mold | die of the injection molding machine of Example 1 of this invention. It is a side view of a stationary side platen and a clamp plate. It is a side view of a movable side platen and a clamp plate. It is a side view of the principal part of a clamp plate and a magnet unit. It is a disassembled perspective view of a magnet unit. It is sectional drawing of the clamp plate (operation state) of a movable side platen. It is sectional drawing of the clamp plate (non-operation state) of a movable side platen. It is sectional drawing of the principal part of a clamp plate and a metal mold | die. It is a side view of an electrode unit. It is sectional drawing of an electrode unit. It is a principal part enlarged view of an electrode unit. It is a disassembled perspective view of an electrode unit. It is a block diagram of the electric circuit of a metal mold | die contact | adherence detection apparatus. It is sectional drawing of the principal part of the clamp plate of Example 2, and a metal mold | die. It is a block diagram of the electric circuit of a metal mold | die contact | adherence detection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection molding machine 2 Fixed side platen 3 Movable side platen 10A, 10B Clamp plate 11, 12 Clamp plate main body 11a, 12a Mold fixed surface 13 Magnet unit 30A, 30B, 80 Mold contact | adherence detection apparatus 31A, 31B, 32A, 32B Electrode unit 31a, 32a Electrode 34 Electrode mounting hole 41 Elastic member 43 Insulating member 50, 50A Electric circuit 60 Photo relay 61 Light emitting diode 65 Detection mechanism 70A, 70B Electric circuit 81A, 81B, 82A, 82B Gap forming mechanism 83 Housing hole 84 Movable Member 86 Spring member 87 Restriction bolt

  Hereinafter, the best mode for carrying out the present invention will be described based on examples.

  As shown in FIG. 1, an injection molding machine 1 includes a fixed side platen 2 and a movable side platen 3 facing each other for fixing a mold M (a fixed side mold M1 and a movable side mold M2), and a mold. In order to perform mold clamping and mold opening of M, four guide rods 4 that guide and support the platen 3 so as to be movable toward and away from the platen 2, and hydraulic pressure that drives the platen 3 to move in the same direction. A platen drive mechanism 5 having a cylinder (or drive motor), an injection mechanism 6 having an injection cylinder 6a for injecting a molten synthetic resin into a cavity in the mold M in a mold-clamped state, and a molded product from the mold M2. An eject mechanism 7 to be pushed out and clamp plates 10A and 10B fixed to the platen surfaces of the platens 2 and 3 are provided.

  Here, as shown in FIGS. 1 and 8, the molds M1 and M2 include mold bodies M1a and M2a and mounting plates M1b and M2a to which the mold bodies M1a and M2a are fixed by a plurality of bolts 29, respectively. M2b. The mounting plates M1b and M2b are formed with a plurality of bolt head receiving holes 29a that open to the back side thereof, and the plurality of bolts 29 are mounted on the mounting plate with the heads received in the bolt head receiving holes 29a. It penetrates M1b and M2b and is screwed and fastened to the mold main bodies M1a and M2a. The mounting plates M1b and M2b of the molds M1 and M2 are fixed to the mold fixing surfaces 11a and 12a of the clamp plates 10A and 10B.

  When injection molding is performed by the injection molding machine 1, the platen drive mechanism 5 drives the platen 3 in the direction approaching the platen 2 after the previous ejection of the molded product, and the mold M2 is pressed against the mold M1 to form the mold. In this state, the injection mechanism 6 injects molten synthetic resin into the mold M from the tip of the injection cylinder 6a to form a molded product. Thereafter, the platen drive mechanism 5 drives the platen 3 in a direction away from the platen 2 to enter the mold open state. In this state, the molded product is ejected from the mold M2 by the eject mechanism 7.

  As shown in FIG. 1, the eject mechanism 7 includes an ejector pin 8, an ejector plate 8a, and a fluid pressure cylinder 8b that moves the ejector pin 8 forward and backward via the ejector plate 8a. The ejector pin 8 is ejector pin. It is inserted through the hole 3c.

  As shown in FIGS. 1 to 3, the platens 2 and 3 are each formed in a square shape in a side view, and the four guide rods 4 are inserted into the insertion holes 2 a in the vicinity of the four corners of the platen 2. The four guide rods 4 are slidably inserted into the insertion holes 3 a in the vicinity of the four corners of the platen 3.

The clamp plates 10A and 10B will be described.
As shown in FIGS. 1 and 2, the clamp plate 10 </ b> A has a mold fixing surface 11 a (hereinafter, referred to as a fixing surface 11 a) for fixing the mold M <b> 1 and is fixed to the platen surface of the platen 2. And a magnet unit 13 which is incorporated in the clamp plate body 11 and can generate a magnetic force for fixing the mold, and corresponds to a plurality of sets of magnetic force generating mechanisms that attract and fix the mold M1 to the fixing surface 11a. I have.

  The clamp plate main body 11 is a steel plate that is a magnetic body of substantially the same size as the platen 2, and substantially square portions corresponding to the four corners of the platen 2 are removed, and a plurality of bolts 14 are provided on the platen 2 surface. It is fixed by. In the clamp plate main body 11, a connector 25 capable of connecting / separating a plurality of electric wires is attached to the rear end portion, and a locate ring 11c is attached to the center portion. The connector 25 is for connecting electrical wiring for supplying current to the plurality of magnet units 13. The locating ring 11c is for centering the mold M1 on the fixed surface 11a by fitting a circular convex portion (not shown) of the mold M1.

  Similarly, as shown in FIGS. 1 and 3, the clamp plate 10 </ b> B has a mold fixing surface 12 a (hereinafter, referred to as a fixing surface 12 a) for fixing the mold M <b> 2 and is fixed to the platen 2 surface. A magnet unit corresponding to a plurality of sets of magnetic force generation mechanisms that are incorporated in the plate main body 12 and the clamp plate main body 12 and that can generate a magnetic force for fixing the mold, and that attract and fix the mold M2 to the fixing surface 12a. 13.

  The clamp plate main body 12 is a steel plate that is a magnetic body of substantially the same size as the platen 3, and substantially square portions corresponding to the four corners of the platen 3 are removed, and a plurality of bolts 14 are formed on the platen 3 surface. It is fixed by. In the clamp plate body 12, a connector 26 capable of connecting / separating a plurality of electric wires is attached to the rear end portion, a block 27 for preventing the mold M2 from falling is attached to the lower end portion, and a pair of pins is provided in the center portion. An ejector pin hole 3c is provided. The connector 26 has the same function as the connector 25.

  The magnet units 13 of the clamp plate 10A have, for example, the number and arrangement shown in FIG. 2, and 10 magnet units in 10 block regions out of 12 block regions formed in the clamp plate main body 11 in a substantially annular shape. 13 and electrode units 31A and 32A, which will be described later, and gap forming mechanisms 81A and 82A are provided in the remaining two block regions. The magnet unit 13 of the clamp plate 10B includes, for example, the number shown in FIG. The 16 magnet units 13 are arranged in 16 block areas formed in a quartered shape on the clamp plate body 12, and the electrode units 31B and 32B and the gap forming mechanism 81B are arranged in areas other than the block areas. , 82B are disposed.

  Since all of the plurality of magnet units 13 of the clamp plates 10A and 10B have basically the same structure, only one magnet unit 13 will be described. However, in the two adjacent magnet units 13, the permanent magnet 23 located on the adjacent side is shared by the two magnet units 13.

  As shown in FIGS. 4 to 7, the magnet unit 13 includes a steel block 20 made of a magnetic material facing the fixed surfaces 11 a and 12 a and a plurality (for example, eight) arranged on the outer peripheral side of the steel block 20. ), A permanent magnet 23 made of a neodymium magnet, an alnico magnet 21 disposed on the back side of the steel block 20, and a coil 22 disposed on the outer peripheral side of the alnico magnet 21 and capable of switching the polarity of the alnico magnet 21. Have

  The steel block 20 and the alnico magnet 21 are formed in a square shape, the steel block 20 is formed with a bolt hole 20a, and the alnico magnet 21 is formed with a hole 21a. The alnico magnet 21 and the coil 22 are disposed in the recess 12b, and the alnico magnet 21 and the coil 22 are sandwiched between the steel block 20 and the bottom wall portion 12c of the clamp plate body 12, and these are bolt holes. The clamp plate body 12 is fastened by a hexagon socket head bolt 24 made of a non-magnetic material (for example, SUS304) that is inserted through the hole 20a and the hole 21a. The plurality of permanent magnets 23 are fixed to the steel block 20 and the clamp plate body 12 by some fixing means.

  In this magnet unit 13, the polarity of the alnico magnet 21 is switched by energizing the coil 22, so that the magnetic path is changed and the operating state when the molds M 1 and M 2 are attracted to the fixed surfaces 11 a and 12 a (FIG. 6). And the non-operating state (see FIG. 7) when the molds M1 and M2 are detached from the fixed surfaces 11a and 12a.

As shown in FIGS. 2, 3, and 8 to 13, the injection molding machine 1 includes a mold contact detection device 30A that detects the contact of the mold M1 to the fixed surface 11a of the clamp plate 10A, and a clamp. A mold contact detection device 30B that detects the contact of the mold M2 to the fixed surface 12a of the plate 10B is provided. In the mold contact detection device 30A, when the mold M1 is not fixed to the fixed surface 11a, a separation gap (between the tip surfaces of electrodes of the electrode units 31A and 32A described later and the mold M1 ( For example, it has a pair of gap forming mechanisms 81A and 82A that form a gap of 0.3 mm. When the mold M2 is not fixed to the fixed surface 12a, the mold contact detection device 30B is spaced apart from the tip surfaces of electrodes 31a and 32a of electrode units 31B and 32B described later and the mold M2. It has a pair of gap forming mechanisms 81B and 82B that form gaps for use (for example, gaps of 0.3 mm).
Since the mold contact detection devices 30A and 30B basically have the same structure and the same function, the mold contact detection device 30B will be described.

  As shown in FIGS. 3 and 8 to 13, the mold contact detection device 30 </ b> B includes an electrode unit 31 </ b> B, an electrode unit 32 </ b> B, electrodes 31 a and 32 a of the electrode units 31 </ b> B and 32 </ b> B, and a mold M. A detection electric circuit 50 connected to a power source 58 is provided. The electrode units 31B and 32B are disposed on the clamp plate body 12 with respect to the center of the fixed surface 12a in the region other than the 16 block regions where the 16 magnet units 13 are disposed as described above. It is incorporated in the target arrangement up and down.

Since the electrode units 31B and 32B have the same structure, the electrode unit 31B will be described.
As shown in FIGS. 8 to 12, the electrode unit 31 </ b> B includes an electrode 31 a, an elastic member 41, and an insulating member 43. The electrode 31a that can be in close contact with the mold M2 is movably mounted in an electrode mounting hole 34 having a circular cross section that is recessed in the clamp plate body 12 so as to open toward the fixed surface 12a. The elastic member 41 mounted in the electrode mounting hole 34 elastically biases the electrode 31a in the direction in which the electrode 31a is in close contact with the mold M2. The insulating member 43 insulates the electrode 31 a from the clamp plate body 12.

  The electrode 31a is obtained by applying gold plating to the surface of a copper main body. The diameter of the circular electrode tip 31b is formed larger than the diameter of the bolt head accommodation hole 29a. A stepped connection hole 36 for connecting the cable 35 and the electrode 31a is formed in the center of the electrode 31a in a penetrating manner.

  On both sides of the electrode 31 a, a pair of circular mounting holes 47 are formed in the clamp plate body 12 so as to partially wrap with the electrode mounting holes 34. A part of the mounting hole 47 is constituted by a notch recess 37a formed in the electrode 31a. The locking members 46 are mounted in the pair of mounting holes 47, respectively. At a position corresponding to the back end of the pair of notch recesses 37a, a pair of locked portions 37b that are respectively locked by a pair of locking members 46 are formed at the bottoms of the pair of notch recesses 37a. Has been. The electrode 31a is elastically biased toward the protruding side by the elastic member 41, and the pair of locked portions 37b are locked by the pair of locking members 46. Therefore, the electrode tip 31b of the electrode 31a is formed by the mold M2. It is configured to protrude about 0.2 mm from the fixed surface 12a without being in close contact with the fixed surface 12a.

  The locking member 46 is made of an insulating synthetic resin material and has a short cylindrical shape. The locking member 46 has a bolt hole and a bolt head accommodation hole. The pair of locking members 46 are fixed to the clamp plate body 12 by bolts 48 via washers 48a. The locking member 46 is fixed so as not to protrude from the mounting hole 47 to the fixing surface 12a.

  The elastic member 41 is made of a relatively thick rubber O-ring. The elastic member 41 is mounted between the clamp plate body 12 and the electrode 31a on the bottom surface side of the electrode mounting hole 34, and constantly biases the electrode 31a toward the mold M2. A gap of about 1.2 mm is formed between the electrode 31a and the bottom surface of the electrode mounting hole 34 in a state where the electrode tip 31b protrudes from the fixed surface 12a by about 0.2 mm, whereby the mold M2 is formed on the fixed surface 12a. The electrode 31a can be retracted until the electrode tip 31b is flush with the fixed surface 12a.

  The insulating member 43 includes a cylindrical member 45 made of synthetic resin and a pair of locking members 46. The cylindrical member 45 is fitted on the electrode 31 a, and the electrode 31 a is mounted in the electrode mounting hole 35 via the cylindrical member 45. The electrode 31a is insulated from the mold M2 by a cylindrical member 45 and a pair of locking members 46. The cylindrical member 45 is formed with a pair of notches 45a at locations corresponding to the pair of notch recesses 37a of the electrode 31a. A pair of locked portions 45b that are locked by a pair of locking members 46 are formed at the base ends of the pair of notches 45a, and the locked portions 45b are locked by the locking members 46. Thus, the tubular member 45 is prevented from coming off.

  The cable 35 penetrates the platen 3 and extends from the insertion hole 12b formed in the clamp plate body 12 into the connection hole 36, and the tip conductive portion 35a of the cable 35 is fixed to the terminal 38 with solder. The terminal 38 is engaged with a step portion in the middle of the connecting hole 36 and fixed with a screw member 39 screwed into the connecting hole 36 from the front end side, and the electrode 31a and the cable 35 are electrically connected. It has become. The cable 35 constitutes a part of a power supply circuit 51 described later.

Next, the detection electric circuit 50 will be described with reference to FIG.
The electric circuit for detection 50 includes a power circuit 51, a diode 53, a resistor 54, a smoothing circuit 55 including a resistor 56 and a capacitor 57, a photorelay 60 including a light emitting diode 61 and a photo MOSFET 62, an electrode 31a, The circuit opening / closing part 63 including the contact part with the mold M2 and the contact part between the electrode 32a and the mold M2 is connected as shown in the figure.
The electric circuit for detection 50 is closed when the electrode 31a and the mold M2 come into contact with each other and the electrode 32a and the mold M2 come into contact with each other.

  A detection mechanism (detection means) 65 for detecting the adhesion of the mold M2 to the mold fixing surface 12a via the detection electric circuit 50 includes the photorelay 60 and a control unit 59, and the photorelay 60 The light emitting diode 61 corresponds to the detection unit of the detection mechanism 65.

  Either an AC power source or a DC power source is connected as the power source 58 of the detection electric circuit 50. The power supply circuit 51 incorporates a DC / DC converter when the power supply 58 is a DC power supply, and incorporates an AC / DC converter when the power supply 58 is an AC power supply. The power supply circuit 51 outputs DC 24V. The diode 53 (for example, 1A, 200V) is a diode for preventing a backflow of current. The resistor 54 (eg, 2.2 kΩ, 0.5 W) is a resistor that limits the current flowing through the light emitting diode 61. The resistor 54 and other components limit the current flowing through the electric circuit 50 to about 10 mA. Has been.

  A smoothing circuit 55 is connected in series to the first resistor 54, and the smoothing circuit 55 is a circuit in which a second resistor 56 (for example, 820Ω, 0.25W) and a capacitor 57 (for example, 1μ, 50V) are connected in parallel. . Since this electric circuit 50 is a circuit including the mold M2, the current output from the power supply circuit 51 is likely to have noise during the operation of the injection molding machine 1. Therefore, noise is removed from the input current input to the light emitting diode 61 by the smoothing circuit 55.

  The light emitting diode 61 (detection unit) is connected in series to the resistor 54 and connected in parallel to the smoothing circuit 55. The photo MOSFET 62 is connected to the control unit 59. When the light emitting diode 61 is energized and emits light, the photo MOSFET 62 is turned on. Therefore, the control unit 59 can detect the close contact between the electrodes 31a and 32a and the mold M2 by detecting ON / OFF of the photo MOSFET 62. Has been. However, it is also possible to detect the light emitted from the light emitting diode 61 by visual observation to detect the close contact between the electrodes 31a and 32a and the mold M2. In this case, the light emitting diode 61 has a detection mechanism. It corresponds to.

  The circuit opening / closing part 63 includes a mold M2 and electrodes 31a and 32a. The electrode 31a is connected to the power supply circuit 51 via the cable 35, and the electrode 32a is connected in series to the smoothing circuit 55 and the light emitting diode 61. Has been. The circuit opening / closing part 63 is closed through the close contact between the electrode 31a and the mold M2 and the close contact between the electrode 32a and the mold M2, and the detection electric circuit 50 is closed.

  A DIP switch 64 is connected in parallel to the circuit opening / closing unit 63. The DIP switch 64 is turned off when the injection molding machine 1 is operating normally. In the test stage where the mold M2 is not fixed, the detection electric circuit 50 can be closed by turning on the DIP switch 64, and the detection electric circuit 50 can be tested.

  Here, as shown in FIG. 2, in the mold contact detection device 30 </ b> A, the electrode units 31 </ b> A and 32 </ b> A and the gap forming mechanisms 81 </ b> A and 82 </ b> A are attached to the clamp plate body 11 or a steel block coupled to the clamp plate body 11. For example, as described above, in the remaining two block areas other than the ten magnet units 13 out of the twelve block areas, the target arrangement with respect to the center of the fixed surface 12a. It has been incorporated.

Next, the pair of gap forming mechanisms 81B and 82B will be described.
As shown in FIG. 3 and FIG. 8, the pair of gap forming mechanisms 81B and 82B is targeted to the center of the fixed surface 12a between the electrode units 31B and 32B of the clamp plate 10B and up and down. It is arranged. Since these have the same structure, one gap forming mechanism 81B will be described. The gap forming mechanism 81B includes a receiving hole 83 formed in the clamp plate body 12, and a protruding position that is mounted in the receiving hole 83 and protrudes from the mold fixing surface 12a by a minute predetermined length (for example, 0.5 mm). A movable member 84 that can be switched to a non-projecting position that does not project, a spring member 86 that is accommodated in the accommodation hole 83 and elastically biases the movable member 84 to the projecting position, and the movable member 84 does not project beyond the projecting position. And a regulating bolt 87 for regulating.

Next, the operation and effect of the mold contact detection device 30B of the injection molding machine 1 will be described.
First, in order to fix the mold M to the clamp plates 10A and 10B, the mold M in a state where the fixed mold M1 and the movable mold M2 are connected to each other with the clamp plates 10A and 10B by a conveying means such as a crane. Transport between 10B. At this time, the plurality of magnet units 13 are inactivated as shown in FIG. 7 and no magnetic force acts on the mold M.

  Next, the mold M1 is positioned and brought into contact with the fixed surface 11a of the clamp plate 10A, and a circular convex portion (not shown) of the mold M1 is fitted to the locating ring 11c to fix the mold M1 to the fixed surface. Center to 11a. At this time, a gap of 0.5 mm is formed between the mold M1 and the fixed surface 11a by the gap forming mechanisms 81A and 82A, so that a gap of 0.3 mm between the tip end surface of the electrode is formed. Is formed. Next, the movable side platen 3 is driven to bring the mold M2 into contact with the fixed surface 12a of the clamp plate 10B. At this time, a gap of 0.5 mm is formed between the mold M2 and the fixed surface 12a by the gap-type mechanisms 81B and 82B, so that a distance of 0.3 mm is provided between the tip surfaces of the electrodes 31a and 32a. A clearance is formed.

  Next, electric power is supplied to each magnet unit 13 from the control device, and each coil 22 is energized for a few seconds in a predetermined direction. As shown in FIG. The magnetic pole of the alnico magnet 21 is switched so as to be the same as the direction of the magnetic flux, and a magnetic circuit having the mold M as a part of the magnetic path is formed. At this time, the movable members 84 of the gap forming members 81A, 82A, 81B, and 82B are pushed from the projecting position to the non-projecting position by the attracting force due to the magnetic force, and the electrodes 31a and 32a are also pushed by the electrode mounting hole 34, respectively. The

  When the mold M2 is normally brought into close contact with the fixed surface 12a, the electric circuit 50 of the mold contact detecting device 30B is closed through the close contact between the electrode 31a and the mold M2 and the close contact between the electrode 32a and the mold M2. The circuit 50 is energized. The control unit 59 detects through the light emitting diode 61 that a current flows through the light emitting diode 61 interposed in the energized electric circuit 50 to emit light and the mold M2 is in close contact with the fixed surface 12a. The injection molding machine 1 is allowed to execute injection molding. At this time, for example, the display lamp of the operation panel may be lit in green.

  On the other hand, when a foreign object is caught between the mold M2 and the fixed surface 12a or a gap of 0.2 mm or more is generated between the mold M2 and the fixed surface 12a due to vibration or the like, the electric circuit 50 will not be closed. In this case, the light emitting diode 61 does not emit light, and the control unit 59 detects that the mold M2 is not in close contact with the fixed surface 12a, and does not allow the injection molding machine 1 to perform injection molding, or injection molding. If the process is being executed, the injection molding machine 1 is brought to an emergency stop. At this time, the display lamp of the operation panel may be lit in red. Note that the mold contact detection device 30A can also detect the presence or absence of contact with the fixed surface 11a of the mold M1 in the same manner as described above.

The mold contact detection device 30B described above has the following effects.
As described above, whether or not the mold M2 is in close contact with the fixed surface 12a of the clamp plate 10B can be reliably detected by the mold contact detection device 30B.
That is, when the mold M2 is not in close contact with the fixed surface 12a, the electrodes 31a and 32a are held in a state of protruding a minute amount (for example, 0.2 mm) from the fixed surface 12a, and the mold is placed on the fixed surface 12a. When M2 is in close contact, the electrodes 31a and 32a can be brought into close contact with the mold M2 while being pressed by the mold M2 and the electrodes 31a and 32a are retracted. In particular, in a state where the mold M is not attracted by the magnet unit 13, even if the mold M2 approaches the mold fixing surface 12a, the gap forming mechanisms 81B and 82B cause the tip surfaces of the electrodes 31a and 32a and the mold to move. Since a gap is surely formed with M, it is not erroneously detected that the mold M is in close contact with the mold fixing surfaces 11a and 12a.

  When the electrodes 31a and 32a are in close contact with the mold M2, the detection circuit 50 connected to the power source 58 causes the photo relay 60 and the control unit 59 connected to the detection circuit 50 to connect the electrodes 31a and 32a. The close contact between 32a and the mold M2 can be detected. In this way, the presence or absence of the mold M2 closely contacting the fixed surface 12a can be easily and reliably detected using the detection electric circuit 50 including the mold M2.

  The diameter of the electrode tip 31b facing the mold M2 is the bolt head receiving hole formed in the mounting plate M2b so as to receive the head of the bolt 29 that fixes the mold body M2a to the mounting plate M2b of the mold M2. Since the diameter is larger than the diameter of 29a, when the mold M2 is in close contact with the fixed surface 12a, even when the electrode tip 31b is opposed to the bolt head receiving hole 29a, the electrode tip 31b is securely in close contact with the mold M2. be able to.

When the mold M2 is separated from the mold fixing surface 12a when the mold M2 is replaced, if the polarity of the Alnico magnet of the magnet unit 13 is switched, the magnetic force that attracts the mold M disappears, so that the gap forming mechanism The movable member 84 is biased from the non-projecting position to the projecting position by elastic biasing by the spring members 86 of 81B and 82B, and a gap for separation is formed between the electrodes 31a and 32a and the mold M2. The close contact between M2 and the fixed surface 12a can be reliably released.
Therefore, it is possible to reliably prevent erroneous detection that the mold M is in the fixed state after the fixing is released.

  Here, it is also possible to detect whether or not the mold M2 is in close contact with the fixed surface 12a via a pair of electrode units 31. However, if foreign matter is caught, the entire surface of the mold M2 may not be in close contact with the fixed surface 12a, and a part of the mold M2 may slightly float from the fixed surface 12a. Therefore, as in the present embodiment, the electrode units 31 and 32 are provided at positions separated from each other, and the detection electric circuit 50 is closed through the close contact between the electrode 31a and the mold M2 and the close contact between the electrode 32a and the mold M2. Since it comprised so that it might be comprised, it can detect reliably whether the whole surface of the metal mold | die M2 contact | adhered to the fixed surface 12a.

  The photo relay 60 including the light emitting diode 61 and the control unit 59 are configured to detect whether or not the mold M2 is in close contact with the fixed surface 12a. The light emitting diode 61 emits light to the outside. It may be configured to visually detect whether the mold M2 is in close contact with the fixed surface 12a.

The second embodiment shows an example in which the mold contact detection device 30B of the first embodiment is changed, and only a configuration different from the first embodiment will be described.
As shown in FIG. 14, a mold contact detection device 80 for detecting the contact of the mold M2 to the fixed surface 12a of the clamp plate body 12 of the clamp plate 10B is provided. The clamp rate 10A is also provided with a mold contact detection device having the same structure and function as the mold contact detection device 80. Here, the mold contact detection device 80 will be described.

  As shown in FIGS. 14 and 15, the mold contact detection device 80 includes electrode units 31B and 32B similar to the electrode unit, gap forming mechanisms 81B and 82B, and electrodes 31a and 32a of the electrode units 31B and 32B. An electric circuit for detection 50 </ b> A configured including the mold M <b> 2 and connected to a power source 58 is provided. The detection electric circuit 50A includes electric circuits 70A and 70B connected in parallel to each other. These electric circuits 70A and 70B have a common power source 58A and a diode 53A, and have basically the same structure as the electric circuit 50 of the first embodiment except for the circuit opening / closing parts 63A and 63B. The description will be omitted and only the circuit opening / closing sections 63A and 63B will be described.

  The circuit opening / closing part 63A of the electric circuit 70A includes a contact part between the electrode 31a and the mold M2. The circuit opening / closing part 63A is closed by the close contact between the electrode 31a and the mold M2, and the electric circuit 70A is closed. The electrode 31a is connected in series to the smoothing circuit 55A and the light emitting diode 61A via the cable 35A. The circuit opening / closing part 63B of the electric circuit 70B includes a contact part between the electrode 32a and the mold M2. The circuit opening / closing part 63B is closed by the close contact between the electrode 32a and the mold M2, and the electric circuit 70B is closed. In the electric circuit 50A according to the second embodiment, the mold contact detection device 80 may be configured such that the electric circuit 70B is omitted.

Next, the operation and effect of the mold contact detection device 80 will be described.
The electrode units 31B and 32B are provided at positions separated from each other. It is assumed that the clamp plate body 12 is grounded. Since the electric circuit 70A including the electrode 31a and the electric circuit 70B including the electrode 32a connected in parallel to the electric circuit 70A are provided, the electrodes 31a and 32a are in close contact with the mold M2 in each of the electric circuits 70A and 70B. In this case, the electric circuits 70A and 70B are closed, the light emitting diodes 61A and 61A are turned on, and the photo MOSFETs 62A and 62A are turned on. Thus, based on the signals from the photorelays 60A and 60A, the control unit 59A detects that the electrodes 31a and 32a are in close contact with the mold M2. For this reason, it can be reliably detected whether or not the entire surface of the mold M2 is in close contact with the fixed surface 12a.

  When both of the electrodes 31a and 32a are not in close contact with the mold M2, both the light emitting diodes 61A and 61A are not lit. Therefore, in the control unit 59A based on the signals from the photorelays 60A and 60A, the electrode 31a , 32a is not in close contact with the mold M2. When any one of the electrodes 31a and 32a is not in close contact with the mold M2, the corresponding one light emitting diode 61A is not lit, and therefore, in the control unit 59A based on the signals from the photorelays 60A and 60A. Then, it is detected that any one of the electrodes 31a and 32a is not in close contact with the mold M2. Therefore, it is possible to easily identify a portion where the mold M2 is not sufficiently adhered to the fixed surface 12a.

  In this embodiment, when the mold M2 is separated from the mold fixing surface 12a when the mold M2 is replaced, the movable member 84 is in the non-projecting position due to the elastic biasing by the spring members 86 of the gap forming mechanisms 81B and 82B. Since the separation gap is formed between the electrodes 31a and 32a and the mold M2, both the electric circuits 70A and 70B can be surely opened, so that the fixing can be performed. It is possible to reliably prevent erroneous detection that the mold M2 is in the fixed state after the release.

Here, the example which changes the said Example partially is demonstrated.
[1] In the first and second embodiments, the present invention is not limited to the mold contact detection device incorporating two sets of electrode units 31 and 32, but to a mold contact detection device incorporating one set or three or more sets of electrode units 31 and 32. It may be configured.
[2] In the above embodiment, the mold contact detection device in which an electrode, an elastic member, and an insulating member are incorporated in a clamp plate incorporating a plurality of sets of magnetic force generation mechanisms has been described, but the platen itself is omitted by omitting the clamp plate body. It is also possible to realize a mold contact detection device incorporating a plurality of sets of magnetic force generation mechanisms, electrodes, elastic members, and insulating members.
[3] In addition, those skilled in the art can implement the present invention with various modifications added thereto without departing from the spirit of the present invention.

  This mold contact detection device of an injection molding machine can accurately and reliably detect the presence or absence of a mold contact with a mold fixing surface of a clamp plate without using a proximity switch or a probe coil.

Claims (6)

A clamp plate main body having a mold fixing surface for fixing a mold and fixed to a platen surface of the platen, and a plurality of sets of magnetic force generating mechanisms incorporated in the clamp plate main body and capable of generating a magnetic force for fixing the mold. In a mold contact detection device for detecting the contact of a mold to the mold fixing surface in an injection molding machine having a clamp plate having,
An electrode that is mounted on an electrode mounting hole formed in the clamp plate body and that is in contact with the mold in close contact with the mold fixing surface;
An elastic member that is mounted in the electrode mounting hole and elastically urges the electrode in a direction in close contact with the mold;
An insulating member for insulating the electrode from the clamp plate body;
An electric circuit for detection configured to include the electrode and the mold and connected to a power source;
A detection unit having at least a part connected to the electric circuit for detection, and detecting adhesion of the mold to the mold fixing surface via the electric circuit for detection;
A mold contact detection device for an injection molding machine, comprising: The clamp plate main body is provided with a gap forming means for forming a gap for separation between the tip surface of the electrode and the mold when the mold is not fixed to the mold fixing surface.
The gap forming means is movable so that it can be switched between a receiving hole formed in the clamp plate main body, a protruding position that is mounted in the receiving hole and protrudes a minute predetermined length from the mold fixing surface, and a non-projecting position that does not protrude. A member, a spring member that is accommodated in the accommodation hole and elastically urges the movable member to a projecting position, and a regulation bolt that restricts the movable member from projecting from the projecting position. Item 2. A mold contact detection device for an injection molding machine according to Item 1.   The tip of the electrode facing the mold is formed larger than the diameter of the bolt head receiving hole formed in the mounting plate so as to receive the head of the bolt that fixes the mold body to the mounting plate of the mold. The mold contact detection device for an injection molding machine according to claim 1 or 2. First and second electrodes are provided at positions spaced apart from each other as the electrodes,
The mold contact detection device for an injection molding machine according to claim 1 or 2, wherein the electric circuit for detection includes a contact portion between the first electrode and the mold and a contact portion between the second electrode and the mold. . First and second electrodes are provided at positions spaced apart from each other as the electrodes,
The electric circuit for detection is a first electric circuit including a contact portion between the first electrode and the mold, and a second electric circuit including a contact portion between the second electrode and the mold, and is in parallel with the first electric circuit. 3. The mold contact detection device for an injection molding machine according to claim 1, further comprising a second electric circuit connected thereto.   The mold contact detection device for an injection molding machine according to claim 1 or 2, wherein the detection unit includes a light emitting diode connected to the electric circuit for detection.

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