Mold clamping device and control method of mold clamping device

Abstract

The invention provides a mold clamping device and a control method of the mold clamping device, which can more reliably fix and hold a mold. A mold clamping device (4) according to one embodiment is provided with: a movable disk (21) and a fixed disk (22) which are disposed facing each other and which are moved relative to each other in an approaching direction and a separating direction; a hydraulic clamp device (40) having a clamp capable of fixing the upper die (31) with respect to the movable plate (21); a hydraulic clamp device (40) having a clamp capable of fixing the lower die (32) with respect to the fixing plate (22); a pneumatic stopper device (80) capable of holding a stopper of the upper die (31) relative to the movable disk (21) is provided. The jig and the stopper are driven by separate drive sources that are independent of each other.

Description

Technical Field

[0001] The invention relates to a mold clamping device and a control method of the mold clamping device. Background Art

[0002] There are known molding machines such as injection molding machines, which supply molding material into the cavity of a mold to produce a resin molded product or other molded product (hereinafter sometimes collectively referred to as a "molded product") of a desired shape. The injection molding machine is composed of a clamping device on which a mold is installed, and an injection device that injects the molding material into the cavity of the mold.

[0003] At a work site where a molded product is formed using an injection molding machine, a mold is replaced according to the molded product. More specifically, the mold used until the replacement is removed from a mold clamping device, and another mold is mounted on the mold clamping device.

[0004] That is, the mold clamping device is configured to be able to fix and release the mold. For example, a conventional mold clamping device includes a fixed platen and a movable platen movable relative to the fixed platen. The fixed platen and the movable platen are provided with clamps respectively. Each clamp is driven by hydraulic pressure or the like and has a stroke between a position to fix the mold and a position to release the mold.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 5-77245 Summary of the invention

[0008] The present invention is intended to make the mold clamping device more reliable in fixing and holding the mold.

[0009] Other subjects and novel features will become apparent from the description of this specification and the accompanying drawings.

[0010] According to one embodiment, the mold clamping device comprises: a first mold mounting plate and a second mold mounting plate that are arranged opposite to each other and are relatively moved in an approaching direction and a separating direction; a first mechanical clamp capable of fixing the first mold relative to the first mold mounting plate; a second mechanical clamp capable of fixing the second mold relative to the second mold mounting plate; and a stopper capable of holding the first mold relative to the first mold mounting plate. The first mechanical clamp, the second mechanical clamp, and the stopper are driven by separate drive sources that are independent of each other.

[0011] Effects of the Invention

[0012] According to one embodiment, it is possible to make the mold clamping device more reliable in fixing and holding the mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1This is a front view schematically showing the structure of an injection molding machine according to one embodiment.

[0014] Figure 2 It is along Figure 1 A partial enlarged cross-sectional view of the mold clamping device of line XX.

[0015] Figure 3A It is along Figure 2 A cross-sectional view of the mold clamping device along line AA.

[0016] Figure 3B It is along Figure 2 A cross-sectional view of the mold clamping device along line BB in FIG.

[0017] Figure 4 This is an enlarged view showing a hydraulic clamp device according to one embodiment.

[0018] Figure 5 yes Figure 4 A cross-sectional view of a hydraulic clamping device is shown.

[0019] Figure 6 yes Figure 4 Another cross-sectional view of the hydraulic clamping device shown.

[0020] Figure 7 This is a system diagram showing a hydraulic system and a pneumatic system included in a mold clamping device according to one embodiment.

[0021] Figure 8 This is an enlarged view showing a gas stopper device according to one embodiment.

[0022] Fig. 9 yes Figure 8 A cross-sectional view of a gas pressure stop device is shown.

[0023] Fig.10 yes Figure 8 Another cross-sectional view of the gas pressure stop device is shown.

[0024] Fig.11 This is a block diagram showing the structure of a control device according to one embodiment.

[0025] Fig.12 1 is a flowchart showing an example of a control method executed by a control device according to an embodiment.

[0026] Fig.13 This is a front view schematically showing the structure of an injection molding machine according to another embodiment.

[0027] Fig.14 It is along Fig.13 A partially enlarged cross-sectional view of the mold clamping device on the YY line in FIG.

[0028] Fig.15A It is along Fig.14 Cross-sectional view of the clamping device of the CC line in FIG.

[0029] Fig. 15B It is along Fig.14 A cross-sectional view of the mold clamping device of the DD line.

[0030] Description of Reference Numerals

[0031] 1A, 1B injection molding machine (molding machine), 2 base, 3 injection device, 4 mold clamping device, 10 heating cylinder, 11 hopper, 12 driving unit, 14 nozzle, 15 notification unit, 21 mold mounting plate (movable plate), 22 mold mounting plate (fixed plate), 21a, 22a mold mounting surface, 23 tie rod, 24 support plate, 25 hydraulic cylinder (mold opening and closing cylinder), 26 mold clamping cylinder, 27 ejector, 28 lifter, 30 mold, 31 Mold (upper mold), 32 mold (lower mold), 33 mold body, 34 mounting plate, 35 mold replacement carriage, 36 fork, 37 fork drive, 40 hydraulic clamp device, 41 main body, 42 clamp, 43 cylinder, 43a, 43b oil chamber, 44 piston, 44a head, 44b rod, 45 push surface, 46a forward side port, 46b backward side port, 48 insertion hole, 50 clamp position detection unit, 51 convex portion, 52 limit switch, 52a actuator, 53 slit, 60 oil tank, 61 pump, 62 hydraulic control equipment group, 63 check valve, 64 pressure control valve, 65 direction switching valve, 66 pressure switch, 70 control device, 71 controller, 72 input interface, 73 output interface, 80 pneumatic stopper device, 81 main body, 82 stopper, 83 bracket, 84 cylinder, 85 cylinder barrel, 85a, 85b air chamber, 86 piston, 86a head, 86b rod, 87 holding surface, 88a forward side port, 88b backward side port, 90 stopper position detection part, 91 convex part, 92, 93 proximity switch, 94 slit, 100 air compressor, 101 air pressure control device group, 102 pressure control valve, 103 direction switching valve, 104 flow control valve, 105 check valve, 110 mold opening and closing mechanism, 111 servo motor, 112 lead screw, 113 nut, P center DETAILED DESCRIPTION

[0032] The following is a detailed description of the embodiments with reference to the accompanying drawings. It should be noted that in all the drawings used to illustrate the embodiments, the same reference numerals are given to components, machines, etc. having the same or substantially the same functions. In addition, components, machines, etc. that have been described once are not described repeatedly in principle.

[0033] (First Embodiment)

[0034] Figure 1 1A is a front view schematically showing an injection molding machine 1A according to the present embodiment. The injection molding machine 1A includes a base 2, an injection device 3, a mold clamping device 4, etc. In the following description, the "injection molding machine 1A" may be simply referred to as the "molding machine 1A".

[0035] Here, the mold clamping device 4 is used as a reference. Figure 1 The side where the injection device 3 is arranged is defined as the "right side", and the side where the mold replacement trolley 35 is arranged is defined as the "left side". However, this definition is only for the convenience of explanation. In addition, the mold replacement trolley 35 will be described later.

[0036] <Injection device>

[0037] The injection device 3 melts the molding material and injects it. In other words, the injection device 3 plasticizes the molding material and injects it. In the present embodiment, the injection device 3 melts the resin material and injects it.

[0038] The injection device 3 includes a heating cylinder 10 and a hopper 11, and a screw is provided inside the heating cylinder 10. The screw is driven by a drive unit 12 controlled by a control device 70 described later. The drive unit 12 includes a drive source (such as a metering motor, an injection motor, etc.) to rotate or advance and retreat the screw.

[0039] The resin material supplied to the heating cylinder 10 via the hopper 11 is melted by shear heat accompanying the rotation of the screw and heat generated from the heater, and is stored in the heating cylinder 10. More specifically, the molten resin is stored in front of the screw in the heating cylinder 10. At this time, the screw retreats.

[0040] When a predetermined amount of molten resin is stored in the heating cylinder 10 , the screw advances. Then, the molten resin stored in the heating cylinder 10 is pushed by the screw and injected from the nozzle 14 .

[0041] <Mold Clamping Device>

[0042] Figure 2 It is along Figure 1 A partially enlarged cross-sectional view of the mold clamping device 4 along the XX line in FIG. Figure 1 and Figure 2 Both show the mold clamping device 4 when the mold is open. Figure 3A It is along Figure 2 A cross-sectional view of the mold clamping device 4 taken along line AA in FIG. Figure 3B It is along Figure 2 A cross-sectional view of the mold clamping device 4 taken along line BB in FIG.

[0043] The mold clamping device 4 includes a mold mounting plate 21 and a mold mounting plate 22 that are arranged opposite to each other. The mold mounting plate 21 and the mold mounting plate 22 are arranged opposite to each other in the vertical direction. More specifically, the mold mounting plate 21 is arranged above the mold mounting plate 22 in the vertical direction. In other words, the mold mounting plate 22 is arranged below the mold mounting plate 21 in the vertical direction.

[0044] The tie rods 23 extend upward from the four corners of the mold mounting plate 22. Each tie rod 23 passes through the four corners of the mold mounting plate 21 and is fixed to a support plate 24 ( Figure 1 ). That is, the positional relationship between the mold mounting plate 21 and the mold mounting plate 22 is defined by the four tie rods 23 penetrating therebetween.

[0045] The mold mounting plate 21 is composed of Figure 1 The plurality of hydraulic cylinders (mold opening and closing cylinders) 25 shown move in a direction approaching the mold mounting platen 22 (downward) and in a direction separating from the mold mounting platen 22 (upward). In other words, the mold mounting platen 21 is raised and lowered relative to the mold mounting platen 22.

[0046] Therefore, in the following description, the mold mounting platen 21 may be referred to as a “movable platen 21 ”, and the mold mounting platen 22 may be referred to as a “fixed platen 22 ”.

[0047] That is, the mold clamping device 4 is a vertical mold clamping device having a movable platen 21 and a fixed platen 22 that face each other in the vertical direction and are relatively moved in the approaching direction and the separating direction. The molding machine 1A having the mold clamping device 4 is a vertical injection molding machine.

[0048] The mold clamping device 4 closes or opens the mold by moving the movable platen 21 in the vertical direction. The mold opening and closing cylinder 25 is mainly used for mold closing or mold opening. In addition, the mold clamping device 4 performs mold clamping in addition to mold closing and mold opening. The mold clamping cylinder 26 is mainly used for mold clamping.

[0049] Figure 1 Two mold opening and closing cylinders 25 are shown in FIG. The cylinder tube of each mold opening and closing cylinder 25 is fixed to the support plate 24 , and the rod of each mold opening and closing cylinder 25 is fixed to the movable plate 21 .

[0050] The mold opening and closing mechanism of the mold clamping device 4 may use a motor, a ball screw mechanism, etc. instead of the mold opening and closing cylinder 25. The number of mold opening and closing mechanisms is not limited to one or four (plural).

[0051] On the other hand, the cylinder tube of the mold clamping cylinder 26 is provided at the center of the support plate 24 and fixed to the support plate 24. In addition, the rod (plunger) of the mold clamping cylinder 26 is fixed to the center of the upper surface of the movable platen 21.

[0052] When the mold clamping cylinder 26 is used in the mold clamping mechanism of the mold clamping device 4, the number of the mold clamping cylinders 26 is not limited to one or four (plural). However, the mold clamping mechanism may use a toggle mechanism, a crank mechanism, etc. driven by a motor instead of the mold clamping cylinder 26.

[0053] <Mold>

[0054] Mainly as Figure 2 As shown in FIG. 1 , the mold 31 is mounted on the movable platen 21 as the mold mounting platen, and the mold 32 is mounted on the fixed platen 22 as another mold mounting platen. In the following description, the mold 31 mounted on the movable platen 21 is sometimes referred to as the "upper mold 31", and the mold 32 mounted on the fixed platen 22 is sometimes referred to as the "lower mold 32". In addition, the upper mold 31 and the lower mold 32 are sometimes collectively referred to as the "mold 30".

[0055] The mold 30 is composed of a mold body 33 and a mounting plate 34. A concave portion or a convex portion is provided on one surface (parting surface) of the mold body 33, and a temperature regulating pipe is provided inside the mold body 33.

[0056] In this embodiment, a convex portion is provided on one side of the mold body 33 of the upper mold 31, and a concave portion is provided on one side of the mold body 33 of the lower mold 32. That is, the upper mold 31 is a cavity mold, and the lower mold 32 is a core mold.

[0057] The temperature regulating pipe forms a flow path for temperature regulating water (cooling water) for cooling the molten resin injected into the cavity to flow inside the mold 30. The temperature regulating water is supplied to the temperature regulating pipe via a hose connected to the mold body 33. Therefore, when the mold 30 is replaced, the hose is connected to the mold body 33. In addition, before replacing the mold 30, the temperature regulating water (heated water) can be supplied to the temperature regulating pipe to heat the mold 30.

[0058] The mounting plate 34 is a plate portion of a predetermined thickness larger than the mold body 33, and extends in a flange shape around the mold body 33. It should be noted that in another embodiment, a plurality of mold bodies are mounted on a mounting plate larger than the mounting plate 34.

[0059] In another embodiment, the mold 30 is provided with a hydraulic cylinder for a hot runner, a gate valve, etc. In this embodiment, when the mold 30 is replaced, electric wires, hydraulic oil piping, etc. are connected to the mold body 33 in addition to the above-mentioned hoses.

[0060] It should be noted that the molded product is held by the upper mold 31. After the mold is opened, the molded product is ejected by the ejector device 27 ( Figure 1 ) is separated from the upper mold 31.

[0061] <Mold replacement trolley>

[0062] See again Figure 1 The mold replacement carriage 35 includes a mold replacement mechanism such as a fork 36 on which the mold 30 is placed and a fork driving unit 37 for moving the fork 36 forward and backward. The fork driving unit 37 is composed of, for example, a hydraulic cylinder, an electric motor, or the like.

[0063] When the mold 30 is carried into the mold clamping device 4, the mold changing carriage 35 carrying the mold 30 is parked on the left side of the mold clamping device 4. Next, the fork 36 is moved forward to insert the mold 30 onto the fixed platen 22. That is, the mold 30 is carried into the mold clamping device 4 by the mold changing mechanism. It should be noted that there is also an embodiment in which a positioning portion, a receiving portion, etc. for defining the carrying-in position (insertion amount) of the mold 30 are provided above or around the fixed platen 22.

[0064] Thereafter, the mold 30 inserted into the fixed plate 22 is lifted by the lift 28 ( Figure 2 ) is supported from below. Thereafter, the fork 36 is retracted and pulled out from the mold clamping device 4.

[0065] On the other hand, when the mold 30 is unloaded from the mold clamping device 4, the mold replacement cart 35 without the mold 30 is parked next to the mold clamping device 4. Next, the mold 30 removed from the fixed platen 22 is floated by the lifter 28 built into the fixed platen 22. Then, the fork 36 is advanced and inserted under the mold 30. Next, the lifter 28 is lowered and the mold 30 is placed on the fork 36. Thereafter, the fork 36 is retracted and the mold 30 is moved to the mold replacement cart 35. That is, the mold 30 is unloaded (recovered) from the mold clamping device 4.

[0066] However, the above replacement sequence is only an example, and there is also an embodiment in which the mold 30 is replaced without using the mold replacement carriage 35. For example, in another embodiment, the mold 30 is moved into and out of the mold clamping device 4 using a rolling body (roller, ball, etc.) provided on the fixed plate 22.

[0067] In addition, a locking mechanism may be provided for fixing the upper mold 31 and the lower mold 32 so as to be separated when the mold 30 is carried out or carried in.

[0068] <Hydraulic clamp device>

[0069] <<Fixture>>

[0070] like Figure 3A As shown, four hydraulic clamp devices 40 are provided on the movable platen 21. More specifically, two hydraulic clamp devices 40 are provided on the front side of the mold mounting surface 21a, and the other two hydraulic clamp devices 40 are provided on the rear side of the mold mounting surface 21a.

[0071] From another perspective, two hydraulic clamp devices 40 are provided on one side of the path for carrying the mold 30 in and out of the mold clamping device 4, and another two hydraulic clamp devices 40 are provided on the other side of the path for carrying the mold 30 in and out of the mold clamping device 4. The hydraulic clamp devices 40 provided on the movable platen 21 include mechanical clamps capable of fixing the mold.

[0072] like Figure 3B As shown, four hydraulic clamp devices 40 are also provided on the fixed platen 22. The configuration of the four hydraulic clamp devices 40 provided on the fixed platen 22 is the same or substantially the same as that of the four hydraulic clamp devices 40 provided on the movable platen 21.

[0073] Specifically, two hydraulic clamp devices 40 are provided on the front side of the mold mounting surface 22a, and another two hydraulic clamp devices 40 are provided on the rear side of the mold mounting surface 22a. The hydraulic clamp devices 40 provided on the fixed plate 22 include mechanical clamps capable of fixing the mold.

[0074] Figure 3A and 3B All the hydraulic clamp devices 40 shown have the same structure. Therefore, only one of the hydraulic clamp devices 40 shown in the figure will be described in detail, and detailed descriptions of the other hydraulic clamp devices 40 will be omitted.

[0075] Figure 4 It is an enlarged view showing one of the four hydraulic clamp devices 40 provided on the movable platen 21 . Figure 5 and Figure 6 yes Figure 4 A cross-sectional view of a hydraulic clamp device 40 is shown.

[0076] like Figure 4 As shown, the hydraulic clamp device 40 includes a main body 41 and a clamp 42 that can reciprocate relative to the main body 41. The clamp 42 is driven by hydraulic pressure and Figure 5 The position shown (advanced position) and Figure 6 The actuator reciprocates between the positions shown (retracted positions).

[0077] The main body 41 of the hydraulic clamp device 40 is fixed to the mold mounting surface 21a of the movable platen 21 by bolts. More specifically, the main body 41 is fixed at a position where its front end surface can face the side surface of the mounting plate 34 mounted on the upper mold 31 of the mold clamping device 4 with a small gap.

[0078] like Figure 5 and Figure 6 As shown, a cylinder 43 is provided in the main body 41, and a steel piston 44 is accommodated in the cylinder 43 in a reciprocating manner. The piston 44 includes a head 44a and a rod 44b.

[0079] The head 44a of the piston 44 partitions the interior of the cylinder 43 into two oil chambers 43a and 43b. The front portion of the rod 44b of the piston 44 has a wedge shape, forming the clamp 42 including the pressing surface 45.

[0080] The side wall of the main body 41 is provided with a forward port 46a communicating with the oil chamber 43a and a backward port 46b communicating with the oil chamber 43b. Figure 6 When the oil is supplied to the oil chamber 43a shown in the figure from the forward port 46a, the piston 44 is pushed out and the clamp 42 moves from the retreat position ( Figure 6 ) to the forward position ( Figure 5 )move.

[0081] On the other hand, when the working oil passes through Figure 5 When the oil is supplied to the oil chamber 43b shown in the figure at the backward side port 46b, the piston 44 is pushed back and the clamp 42 moves from the forward position ( Figure 5 ) to the backward position ( Figure 6 ) moves. That is, the hydraulic clamp device 40 is a double-acting hydraulic cylinder.

[0082] A coil spring 47 is disposed between the bottom of the cylinder 43 and the head 44a. One end of the coil spring 47 abuts against the bottom surface of the cylinder 43, and the other end of the coil spring 47 is inserted into an insertion hole 48 provided in the head 44a.

[0083] The coil spring 47 always urges the piston 44 forward (toward the advanced position). Thus, the clamp 42 is held at the advanced position even when hydraulic oil is not supplied to the oil chambers 43a and 43b.

[0084] As described above, the other hydraulic clamp device 40 has the same structure as the above hydraulic clamp device 40 and operates in the same manner as the above hydraulic clamp device 40. The main body 41 of the hydraulic clamp device 40 provided on the fixed plate 22 is fixed to the upper surface (mold mounting surface 22a) of the fixed plate 22 with bolts.

[0085] like Figure 5 As shown in FIG. 1 , when the clamp 42 of the hydraulic clamp device 40 provided on the movable platen 21 moves to the advanced position, it abuts against the mounting plate 34 of the upper die 31 and pushes the mounting plate 34. More specifically, the pushing surface 45 of the clamp 42 abuts against the clamp abutting surface of the lower surface of the mounting plate 34 and pushes the mounting plate 34 upward. As a result, the plate abutting surface of the mounting plate 34 is pressed against the mold mounting surface 21a of the movable platen 21, and the upper die 31 is fixed to the movable platen 21.

[0086] On the other hand, Figure 6As shown in FIG. 1 , when the clamp 42 of the hydraulic clamp device 40 provided on the movable platen 21 moves to the retracted position, the clamp contact surface with the mounting plate 34 of the upper die 31 is separated and retreated to the periphery of the upper die 31. As a result, the pressing of the mounting plate 34 on the die mounting surface 21a of the movable platen 21 is released. That is, the fixing of the upper die 31 to the movable platen 21 is released.

[0087] The clamps 42 of the hydraulic clamp device 40 provided on the fixed platen 22 fix and release the lower mold 32 to the fixed platen 22 by substantially the same operation as the clamps 42 of the hydraulic clamp device 40 provided on the movable platen 21 .

[0088] Specifically, when the clamp 42 of the hydraulic clamp device 40 provided on the fixed platen 22 moves to the advanced position, it abuts against the mounting plate 34 of the lower die 32 and pushes down the mounting plate 34. More specifically, the pressing surface 45 of the clamp 42 abuts against the clamp abutting surface on the upper surface of the mounting plate 34 and pushes down the mounting plate 34. As a result, the plate abutting surface of the mounting plate 34 is pressed against the mold mounting surface 22a of the fixed platen 22, and the lower die 32 is fixed to the fixed platen 22.

[0089] On the other hand, when the clamp 42 of the hydraulic clamp device 40 provided on the fixed platen 22 moves to the retracted position, the clamp contact surface with the mounting plate 34 of the lower mold 32 is separated and retreated to the periphery of the lower mold 32. As a result, the pressing of the mounting plate 34 against the mold mounting surface 22a of the fixed platen 22 is released. That is, the fixing of the lower mold 32 to the fixed platen 22 is released.

[0090] As described above, the four clamps 42 provided on the movable platen 21 can reciprocate between the advanced position to fix the upper mold 31 and the retreated position to separate from the upper mold 31 and not fix the upper mold 31 .

[0091] Likewise, the four clamps 42 provided on the fixed platen 22 can reciprocate between an advanced position at which the lower mold 32 is fixed, and a retreated position at which the lower mold 32 is separated from the advanced position and is not fixed.

[0092] In addition, the eight clamps 42 are mechanical clamps that abut against the mold 30 to fix the mold 30. In the present invention, the mechanical clamp driven by hydraulic pressure refers to a component that pushes, engages, clamps, holds, etc. at least a part of the mold through the operation of the hydraulic cylinder as a driving part, thereby fixing the mold to the mold mounting plate. Therefore, a clamp that fixes the mold to the mold mounting plate only by the magnetic force of an electromagnet does not belong to a mechanical clamp. In addition, the number of mechanical clamps provided on the mold mounting plate is not limited as long as it is more than two.

[0093] <<Jig position detection unit>>

[0094] like Figure 4 As shown, the hydraulic clamp device 40 includes a clamp position detector 50 for detecting the position of the clamp 42. The clamp position detector 50 is composed of a convex portion 51 provided on the piston 44 and a limit switch 52 provided on the body 41. The convex portion 51 is, for example, the head of a bolt threadedly connected to the piston 44.

[0095] The projection 51 provided on the piston 44 protrudes outside the body 41 through a slit 53 formed in the side wall of the body 41. Thus, the projection 51 reciprocates in the slit 53 along the longitudinal direction of the slit 53 as the clamp 42 advances and retreats.

[0096] The limit switch 52 is fixed to the side of the main body 41, and the actuator 52a of the limit switch 52 extends across the slit 53. Therefore, the convex portion 51 that moves in the slit 53 as the clamp 42 advances contacts the actuator 52a during the process and gradually pushes up the actuator 52a. Then, when the clamp 42 moves to the advanced position, the contact of the limit switch 52 is closed and a detection signal is output. As a result, it is detected that the clamp 42 has moved to the advanced position.

[0097] On the other hand, when the clamp 42 moves to the retreat position, the upward push of the actuator 52a by the convex portion 51 is released. As a result, the contact of the limit switch 52 opens and the detection signal is interrupted. As a result, it is detected that the clamp 42 moves to the retreat position.

[0098] However, there is also an embodiment in which when the clamp 42 moves to the retreat position, the other contact of the limit switch 52 is closed (contact switching), thereby outputting a detection signal.

[0099] In addition, the upward push of the actuator 52a by the convex portion 51 may be released before the clamp 42 moves (arrives) to the retreated position. For example, the upward push of the actuator 52a by the convex portion 51 may be released when the clamp 42 moves to an intermediate position between the forward position and the retreated position. In this case, the clamp position detection unit 50 detects that the clamp 42 has left the forward position.

[0100] The structure of the clamp position detection unit 50 is not limited to the above structure. For example, the limit switch 52 may be a plunger type, a hinge type, a roller type, or a rod type, instead of the rod type described above. In addition, the clamp position detection unit 50 may be formed by a non-mechanical switch (proximity switch) such as a magnetic sensor or a light sensor instead of a mechanical switch such as the limit switch 52.

[0101] Hydraulic System

[0102] The mold clamping device 4 includes a hydraulic system for operating the hydraulic clamp device 40 as described above. Figure 7 1 is a system diagram showing a hydraulic system and a pneumatic system included in the mold clamping device 4. The pneumatic system will be described later.

[0103] The hydraulic system is composed of an oil tank 60, a pump 61, a hydraulic control device group 62, etc. A flow path of the working oil is formed by piping between the pump 61 and each hydraulic clamp device 40, and a hydraulic control device group 62 is provided in each flow path.

[0104] More specifically, mutually independent flow paths are formed between the pump 61 and each hydraulic clamp device 40. Hydraulic control devices such as a check valve 63, a pressure control valve 64, a direction switching valve 65, and a pressure switch 66 are provided on each flow path.

[0105] The hydraulic control device group 62 is controlled by the control device 70. The control device 70 supplies the hydraulic oil to one of the oil chambers 43a and 43b of the hydraulic clamp device 40 (cylinder 43), for example, by switching the direction switching valve 65. As described above, when the hydraulic oil is supplied to one of the oil chambers 43a and 43b, the clamp 42 moves forward and backward.

[0106] The pressure (hydraulic pressure) of the working oil supplied to the hydraulic clamp device 40 (cylinder 43) under the control of the control device 70 is detected by the pressure switch 66 and fed back to the control device 70. More specifically, an interlock circuit is formed in which the pressure switch 66 is activated when the pressure of the working oil exceeds a threshold value and a detection signal is input to the control device 70. In addition, the details of the control device 70 will be described later.

[0107] The driving source of the pump 61 is not particularly limited, but the pump 61 of this embodiment is driven by a servo motor. In addition, the pump 61 supplies hydraulic oil not only to the hydraulic clamp device 40, but also to other hydraulic equipment (such as the mold opening and closing cylinder 25, the mold clamping cylinder 26, etc.).

[0108] In addition, for the mechanical clamp that fixes the upper mold 31 mounted on the movable platen 21, the following structure can be adopted to cope with the possibility of failure of the hydraulic control device group 62 such as the check valve 63, the pressure control valve 64, the direction switching valve 65, the pressure switch 66, etc. That is, a structure in which the working oil is supplied to one hydraulic clamp device 40 through multiple (for example, two) hydraulic control device groups 62 can be adopted. With this structure, for example, even if the direction control valve 65 or its signal line of one hydraulic control device group 62 becomes inoperative due to a failure, the working oil can continue to be supplied to the oil chamber 43a of a specific hydraulic clamp device 40 through another hydraulic control device group 62.

[0109] <Air pressure stopper device>

[0110] <<Stop>>

[0111] like Figure 3A As shown, the movable plate 21 as the mold mounting plate is provided with a pair of gas pressure stopper devices 80 capable of holding the upper mold 31. More specifically, one gas pressure stopper device 80 is provided on the front side of the mold mounting surface 21a, and another gas pressure stopper device 80 is provided on the rear side of the mold mounting surface 21a.

[0112] The two gas pressure stopper devices 80 are offset from each other with respect to the center P of the mold 30 (upper mold 31). More specifically, the gas pressure stopper device 80 provided on the front side of the mold mounting surface 21a is offset to the left with respect to the center P of the mold 30 (upper mold 31). On the other hand, the gas pressure stopper device 80 provided on the rear side of the mold mounting surface 21a is offset to the right with respect to the center P of the mold 30 (upper mold 31).

[0113] In other words, the two gas stopper devices 80 are in a point-symmetrical positional relationship with the center P of the mold 30 (upper mold 31 ) as a symmetrical point.

[0114] The two gas pressure stopper devices 80 shown in the figure have the same structure. Therefore, only one gas pressure stopper device 80 will be described in detail, and the detailed description of the other gas pressure stopper device 80 will be omitted.

[0115] Figure 8 1 is an enlarged view showing one of the two gas pressure stopper devices 80 provided on the movable plate 21 . Fig. 9 and Fig.10 yes Figure 8 A cross-sectional view of a gas pressure stop device 80 is shown.

[0116] like Figure 8 As shown, the gas pressure stopper device 80 includes a main body 81 and a stopper 82 that can reciprocate relative to the main body 81. The stopper 82 is driven by gas pressure and Fig. 9 The position shown (advanced position) and Fig.10 The actuator reciprocates between the positions shown (retracted positions).

[0117] The main body 81 has a bracket 83 and a cylinder 84, and is fixed to the mold mounting surface 21a of the movable plate 21. More specifically, the main body 81 is fixed at a position so that its front end surface (the front end surface of the bracket 83) can face the side surface of the mounting plate 34 of the upper mold 31 mounted on the mold clamping device 4 through a small gap.

[0118] The air cylinder 84 includes a cylinder tube 85 and a steel piston 86 accommodated in the cylinder tube 85 so as to be reciprocable. The cylinder tube 85 is fixed to the bracket 83 via a rod penetrating flanges disposed on both sides of the cylinder tube 85 in the longitudinal direction.

[0119] like Fig. 9 and Fig.10 As shown, the piston 86 includes a head 86a and a rod 86b. The head 86a of the piston 86 divides the interior of the cylinder 85 into two air chambers 85a and 85b. The front part of the rod 86b of the piston 86 is plate-shaped and forms a stopper 82 with a retaining surface 87.

[0120] The side wall of the cylinder 85 is provided with a forward port 88a communicating with the air chamber 85a and a backward port 88b communicating with the air chamber 85b. Fig.10 When the forward port 88a shown in the figure supplies air to the air chamber 85a shown in the figure, the piston 86 is pushed out and the stopper 82 is moved from the retracted position ( Fig.10 ) to the forward position ( Fig. 9 )move.

[0121] On the other hand, when compressed air passes through Fig. 9 When the air is supplied to the air chamber 85b shown in the figure at the rearward side port 88b, the piston 86 is pushed back and the stopper 82 is moved from the forward position ( Fig. 9 ) moves to the back position ( Fig.10 ). That is, the air stopper device 80 is a double-acting air cylinder.

[0122] like Fig. 9 As shown, when the stopper 82 of the gas pressure stopper device 80 moves to the advanced position, it enters below the mounting plate 34 of the upper mold 31. Thus, at least the holding surface 87 of the stopper 82 is arranged on the lower side of the mounting plate 34 of the upper mold 31 in the vertical direction.

[0123] Therefore, the upper mold 31 no longer fixed by the clamp 42 as a mechanical clamp abuts against at least the holding surface 87 of the stopper 82 and is held. More specifically, the lower surface (which is the same plane as the clamp abutting surface) of the mounting plate 34 of the upper mold 31 no longer fixed by the clamp 42 is received by the holding surfaces 87 of the two stoppers 82 and is supported from the lower side in the vertical direction. That is, even if the upper mold 31 is no longer fixed by the clamp 42, the upper mold 31 will not immediately detach (fall) from the movable plate 21.

[0124] As described above, the front end surface of the hydraulic clamp device 40 (body 41 ) and the front end surface of the gas stopper device 80 (body 81 ) face the side surface of the mounting plate 34 of the upper mold 31 with a small gap therebetween.

[0125] Therefore, the mounting plate 34 of the upper mold 31 is clamped by the hydraulic clamp device 40 and the gas pressure stopper device 80 on the front side and the hydraulic clamp device 40 and the gas pressure stopper device 80 on the rear side and cannot rotate between them (see Figure 3A ).

[0126] As a result, even if the fixation by the clamp 42 is released, the upper mold 31 can be stably held by only the two stoppers 82. The stoppers 82 only need to have the ability and strength to hold the upper mold 31 so that it does not fall. From another perspective, the stoppers 82 may not have the ability and strength to support the upper mold 31 during normal continuous molding. For example, the stoppers 82 may not have the ability and strength to support the upper mold 31 when the upper mold 31 is demolded relative to the lower mold 32. Therefore, it is possible to try to reduce costs by controlling the number, ability, etc. of the stoppers 82 to the minimum under necessary conditions.

[0127] Furthermore, in the present embodiment, the two stoppers 82 are offset from each other with respect to the center P of the upper mold 31. Therefore, the upper mold 31 does not rotate with one of the stoppers 82 as a fulcrum. Therefore, the upper mold 31 can be more stably held by only the two stoppers 82. However, the case where the movable plate 21 is provided with three or more stoppers 82 is not excluded. In this case, the stoppers 82 are provided in pairs on both sides of the upper mold 31. Furthermore, although it is desirable that the total number of the stoppers 82 is an even number, the case where the total number of the stoppers 82 is an odd number is not excluded.

[0128] Furthermore, when the stoppers 82 are provided in pairs, as long as at least one of the stoppers 82 is driven by a driving source such as air pressure, the other stopper 82 may not have a driving source. For example, the stopper 82 not having a driving source may be provided with only a receiving portion capable of holding the upper mold 31. Alternatively, the two stoppers 82 may be driven by one driving source via a link mechanism or the like.

[0129] In addition, the retaining surface 87 of the stopper 82 moved to the forward position is opposite to the lower surface of the mounting plate 34 with a small gap (e.g., 1 mm). From another perspective, the stopper 82 moved to the forward position is in a position slightly separated from the mounting plate 34 so as to be able to hold the upper mold 31.

[0130] By utilizing the gap (distance) between the mounting plate 34 and the stopper 82 (holding surface 87 ), interference between the mounting plate 34 and the stopper 82 is avoided, thereby ensuring smooth forward and backward movement of the stopper 82 .

[0131] In another embodiment, all or part of the stopper 82 moved to the advanced position may abut against the upper mold 31 all the time or at least during mold closing.

[0132] like Fig.10As shown, the stopper 82 of the gas pressure stopper device 80, when moved to the retracted position, retreats to the periphery of the upper mold 31. That is, the two stoppers 82 provided on the movable platen 21 can reciprocate between the advanced position in which the upper mold 31 is held, and the retracted position in which the upper mold 31 is separated from the advanced position and the upper mold 31 is not held.

[0133] From another perspective, in order for the upper mold 31 to be detached from the movable platen 21 , at least two conditions must be satisfied (the clamp 42 moves to the retracted position, and the stopper 82 moves to the retracted position).

[0134] <<Stopper Position Detection Section>>

[0135] like Figure 8 As shown, the pneumatic stopper device 80 has a stopper position detection unit 90 for detecting the position of the stopper 82. The stopper position detection unit 90 is composed of a convex portion 91 provided on the piston 86 and two proximity switches 92 and 93 provided on the main body 81 (bracket 83). The convex portion 91 is, for example, a cam provided on the piston 86.

[0136] The projection 91 provided on the piston 86 protrudes outside the bracket 83 through the slit 94 formed in the side wall of the bracket 83. Thus, the projection 91 reciprocates in the slit 94 along the longitudinal direction of the slit 94 as the stopper 82 advances and retreats.

[0137] The proximity switches 92, 93 are fixed to the side surfaces of the bracket 83. In addition, the proximity switches 92, 93 are separated from each other in the long-side direction of the slit 94.

[0138] When the stopper 82 moves to the forward position, the convex portion 91 is detected by one proximity switch 92, and a detection signal is output. In addition, when the stopper 82 moves to the backward position, the convex portion 91 is detected by another proximity switch 93, and a detection signal is output. Thus, it is detected that the stopper 82 moves to the forward position or the backward position.

[0139] However, the structure of the stopper position detection unit 90 is not limited to the above structure. For example, the proximity switches 92 and 93 may be replaced with mechanical switches such as the limit switch 52, other non-contact switches, and the like.

[0140] Furthermore, it can be determined that the stopper 82 is separated from the forward position when the signal output from the proximity switch 92 is interrupted. In this case, it is possible to detect the stopper 82 reaching the forward position and separating from the forward position using only the proximity switch 92.

[0141] <<Air Pressure System>>

[0142] As described above, the mold clamping device 4 has Figure 7The pneumatic system shown in FIG. The pneumatic system is composed of an air compressor 100, a pneumatic control device group 101, etc. More specifically, a flow path of compressed air is formed by piping between the air compressor 100 and the two pneumatic stopper devices 80, and the pneumatic control device group 101 is provided on the flow path.

[0143] The air pressure control device group 101 includes at least a pressure control valve 102 , a directional switching valve 103 , a flow control valve 104 , and a check valve 105 .

[0144] The air pressure control device group 101 is controlled by the control device 70. The control device 70 supplies compressed air to the air chambers 85a and 85b of the air pressure stopper device 80 (cylinder 84), for example, by switching the direction switching valve 103. As described above, when the compressed air is supplied to the air chambers 85a and 85b, the stopper 82 moves forward and backward.

[0145] The clamp 42 is driven by hydraulic pressure, while the stopper 82 is driven by air pressure. That is, the clamp 42 and the stopper 82 are driven by separate drive sources independent of each other. In addition, the hydraulic system for operating the clamp 42 and the air pressure system for operating the stopper 82 are also independent of each other.

[0146] Therefore, even if some kind of failure occurs in the hydraulic system, the stopper 82 can function normally without being affected in any way.

[0147] However, the driving source of the stopper 82 only needs to be independent of the driving source of the clamp 42, and is not limited to air pressure. For example, the driving source of the stopper 82 may be changed to hydraulic pressure, and the stopper 82 may be operated by a hydraulic system independent of the hydraulic system for operating the clamp 42. In addition, the stopper 82 may be driven by an electric cylinder, an electric motor, or the like.

[0148] <Control device>

[0149] Next, Figure 7 The control device 70 shown in the figure is used for overall control of the molding machine 1A including the injection device 3 and the mold clamping device 4. Fig.11 It is a block diagram showing the structure of the control device 70.

[0150] The control device 70 includes a controller 71, an input interface 72, an output interface 73, etc. The controller 71 is composed of a CPU, a memory, etc. which are connected to each other so as to be able to communicate with each other.

[0151] Various detection signals, information, etc. are input to the controller 71 through the input interface 72. The controller 71 processes the input detection signals, information, etc. according to the program stored in the memory, and generates a command signal based on the processing result. The controller 71 outputs the generated command signal to various devices, equipment, etc. via the output interface 73.

[0152] As mentioned above from Figure 7 The detection signal outputted from the illustrated pressure switch 66 is inputted to the control device 70 , and more specifically, the detection signal outputted from the pressure switch 66 is inputted to the controller 71 via the input interface 72 .

[0153] In addition, from Figure 4 The detection signal output by the limit switch 52 shown in FIG. Figure 8 Detection signals output by the proximity switches 92 , 93 shown are also input to the controller 71 .

[0154] On the other hand, the controller 71 controls the hydraulic clamp device 40, the pneumatic stopper device 80, etc. by outputting command signals to the devices constituting the hydraulic system, the pneumatic system, etc. For example, the controller 71 switches the direction switching valve 65 of the hydraulic system to advance and retreat the clamp 42. In addition, the controller 71 also switches the direction switching valve 103 of the pneumatic system to advance and retreat the stopper 82.

[0155] Furthermore, the controller 71 also outputs command signals to the driving unit 12 and the notification unit 15 of the injection device 3. The notification unit 15 is, for example, a monitor capable of displaying messages, a speaker capable of generating warning sounds, and the like.

[0156] <Control method>

[0157] Fig.12 is a flowchart showing an example of a control method executed by the control device 70. Fig.12 In step S1 shown, it is determined whether the clamps 42 of all the hydraulic clamp devices 40 have moved to the advanced position. Specifically, it is determined whether the detection signals are outputted from all the limit switches 52.

[0158] If it is determined in step S1 that some or all of the clamps 42 of the hydraulic clamp device 40 have not moved to the advanced position, the process proceeds to step S5. Specifically, if it is determined that a detection signal is not output from some or all of the limit switches 52, the process proceeds to step S5.

[0159] In step S5, a command signal is output to the notification unit 15. The notification unit 15 to which the command signal is input displays a warning message or emits a warning sound according to the command.

[0160] On the other hand, if it is determined in step S1 that the clamps 42 of all the hydraulic clamp devices 40 have moved to the advanced position, the process proceeds to step S2 .

[0161] In step S2, it is determined whether the pressure in the oil chamber 43a of all the hydraulic clamp devices 40 has increased. From another perspective, it is determined whether the hydraulic oil having a pressure exceeding a threshold is being supplied to all the hydraulic clamp devices 40. Specifically, it is determined whether the detection signal is output from all the pressure switches 66.

[0162] If it is determined in step S2 that the pressure in part or all of the oil chamber 43a of the hydraulic clamp device 40 has not risen sufficiently, the process proceeds to step S5. Specifically, if it is determined that the detection signal is not output from part or all of the pressure switches 66, the process proceeds to step S5.

[0163] On the other hand, if it is determined in step S2 that the hydraulic oil having a pressure exceeding the threshold is being supplied to all the hydraulic clamp devices 40 , the process proceeds to step S3 .

[0164] In step S3, it is determined whether the stoppers 82 of the two gas pressure stopper devices 80 have moved to the forward position. Specifically, it is determined whether detection signals are output from both of the two proximity switches 92.

[0165] If it is determined in step S3 that the stopper 82 of one or both of the gas pressure stopper devices 80 has not moved to the forward position, the process proceeds to step S5. Specifically, if it is determined that the detection signal is not output from one or both of the proximity switches 92, the process proceeds to step S5.

[0166] On the other hand, if it is determined in step S3 that the stoppers 82 of the two air stopper devices 80 have moved to the forward position, the process proceeds to step S4 to allow relative movement of the movable platen 21 and the fixed platen 22. Specifically, the supply of hydraulic oil to the mold opening and closing cylinder 25 is allowed.

[0167] In the above control method, if at least three conditions are not satisfied (the clamp 42 moves to the forward position, the pressure in the oil chamber 43a rises, and the stopper 82 moves to the forward position), the mold opening and closing actions are not performed. From another perspective, the mold clamping device 4 has an interlocking function that does not allow the mold opening and closing actions unless all of the above three conditions are satisfied.

[0168] From the above description, we can see that Fig.11 The CPU shown can function as an interlock control unit, a command signal generating unit, etc., and the memory can function as a sequential circuit storage unit. It can also be understood that the input interface 72 can function as a signal input unit, and the output interface 73 can function as a signal output unit.

[0169] It should be noted that the positions of the clamp 42, the stopper 82, etc. can be continuously monitored even during the manufacture of the molded product. In this case, when the clamp 42, the stopper 82, etc. are no longer detected in the forward position, the control device 70 immediately executes step S5 and stops the operation of the molding machine 1A.

[0170] (Second Embodiment)

[0171] Fig.13 FIG. 1 is a front view schematically showing an injection molding machine 1B according to the present embodiment. The injection molding machine 1B has Figure 1 Therefore, the description of the same or substantially the same structure as the molding machine 1A is omitted, and the differences from the molding machine 1A are mainly described. In addition, in the following description, the "injection molding machine 1B" is sometimes referred to as the "molding machine 1B".

[0172] The mold clamping device 4 of the molding machine 1A is a vertical mold clamping device, so the molding machine 1A is a vertical injection molding machine. On the other hand, the mold clamping device 4 according to the present embodiment is a horizontal mold clamping device, so the molding machine 1B is a horizontal injection molding machine.

[0173] <Mold Clamping Device>

[0174] The movable platen 21 and the fixed platen 22 of the mold clamping device 4 according to this embodiment are arranged horizontally opposite to each other. More specifically, the movable platen 21 is arranged horizontally on the left side of the fixed platen 22. In other words, the fixed platen 22 is arranged horizontally on the right side of the movable platen 21.

[0175] The positional relationship between the movable platen 21 and the fixed platen 22 is defined by four tie rods 23 extending in the horizontal direction (left-right direction). The movable platen 21 moves toward the fixed platen 22 (right direction) and away from the fixed platen 22 (left direction) by the mold opening and closing mechanism 110.

[0176] The mold opening and closing mechanism 110 is a servo mechanism. More specifically, the mold opening and closing mechanism 110 includes a servo motor 111, a lead screw 112, a nut 113, etc. The lead screw 112 is supported at both ends by bearings (ball bearings) and is rotationally driven by the servo motor 111.

[0177] When the screw shaft 112 is driven to rotate by the servo motor 111, the movable platen 21 moves left and right. That is, the movable platen 21 and the fixed platen 22 move relative to each other in the approaching direction and the separating direction by the mold opening and closing mechanism 110.

[0178] The servo motor 111 is controlled by the control device 70 via a servo amplifier. As a result, the mold 31 fixed to the movable platen 21 by the hydraulic clamp device 40 moves relative to the mold 32 fixed to the fixed platen 22 by the hydraulic clamp device 40, and the mold is opened or closed. Fig.13 The mold is shown in an open state. In addition, mold closing is performed by a mold closing cylinder, a toggle mechanism, etc. of a mold closing mechanism (not shown).

[0179] <Hydraulic clamp device and pneumatic stopper device>

[0180] Fig.14 It is along Fig.13 A partially enlarged cross-sectional view of the mold clamping device 4 along the YY line in FIG. Fig.15A It is along Fig.14 A cross-sectional view of the mold clamping device 4 along the CC line in FIG. Fig. 15B It is along Fig.14 A cross-sectional view of the mold clamping device 4 taken along line DD in FIG.

[0181] Four hydraulic clamp devices 40 having mechanical clamps capable of fixing the mold 31 (movable mold) are provided on the movable platen 21 as the mold mounting platen. More specifically, two hydraulic clamp devices 40 are provided on the upper side of the mold mounting surface 21a, and the other two hydraulic clamp devices 40 are provided on the lower side of the mold mounting surface 21a.

[0182] Similarly, the fixed plate 22 as the mold mounting plate is also provided with four hydraulic clamp devices 40 having mechanical clamps capable of fixing the mold 32 (fixed mold). More specifically, two hydraulic clamp devices 40 are provided on the upper side of the mold mounting surface 22a, and the other two hydraulic clamp devices 40 are provided on the lower side of the mold mounting surface 22a.

[0183] In addition, two gas pressure stopper devices 80 capable of holding the mold 31 are provided on the movable platen 21, and two gas pressure stopper devices 80 capable of holding the mold 32 are provided on the fixed platen 22. More specifically, two gas pressure stopper devices 80 are provided on the upper side of the mold mounting surface 21a, and two gas pressure stopper devices 80 are also provided on the upper side of the mold mounting surface 22a.

[0184] The two gas pressure stopper devices 80 provided on the movable platen 21 are arranged between the two hydraulic clamp devices 40 provided on the upper side of the movable platen 21. Similarly, the two gas pressure stopper devices 80 provided on the fixed platen 22 are arranged between the two hydraulic clamp devices 40 provided on the upper side of the fixed platen 22.

[0185] The hydraulic clamp device 40 and the pneumatic stopper device 80 of this embodiment are Figure 7The hydraulic system and the pneumatic system shown are substantially connected to the same system. However, the mold clamping device 4 according to the present embodiment is provided with four pneumatic stopper devices 80. Therefore, the number of branches of the pneumatic system increases according to the number of pneumatic stopper devices 80.

[0186] Fig. 15B The stopper 82 of the pneumatic stopper device 80 provided on the movable plate 21 as shown protrudes in front of the mounting plate 34 of the mold 31 when it moves to the advanced position. Fig.15A The stopper 82 of the pneumatic stopper device 80 shown disposed on the fixed plate 22 protrudes forward of the mounting plate 34 of the mold 32 when moved to the advanced position.

[0187] Therefore, the upper portion of the mold 31 which is no longer fixed by the clamp 42 is held by the two stoppers 82. In addition, the upper portion of the mold 32 which is no longer fixed by the clamp 42 is also held by the two stoppers 82.

[0188] More specifically, even if the upper portion of the mold 31 (the portion of the mounting plate 34) no longer fixed by the clamp 42 moves in a direction away from the mold mounting surface 21a, it is caught by the holding surfaces 87 of the two stoppers 82. Furthermore, even if the upper portion of the mold 32 (the portion of the mounting plate 34) no longer fixed by the clamp 42 moves in a direction away from the mold mounting surface 22a, it is caught by the holding surfaces 87 of the other two stoppers 82.

[0189] Therefore, even if the molds 31 , 32 are no longer fixed by the clamps 42 , these molds 31 , 32 do not immediately come off (fall down) from the movable platen 21 .

[0190] It should be noted that the two gas pressure stopper devices 80 provided on the movable platen 21 are offset from each other with respect to the center P of the mold 31 . Similarly, the two gas pressure stopper devices 80 provided on the fixed platen 22 are also offset from each other with respect to the center P of the mold 32 .

[0191] More specifically, Fig. 15B One of the pneumatic stopper devices 80 shown disposed on the movable plate 21 is offset toward the front side (operating side) relative to the center P of the mold 31, while the other pneumatic stopper device 80 is offset toward the rear side (the side opposite to the operating side) relative to the center P of the mold 31.

[0192] in addition, Fig.15A One of the pneumatic stopper devices 80 shown disposed on the fixed plate 22 is offset toward the front side (operating side) relative to the center P of the mold 32, while the other pneumatic stopper device 80 is offset toward the rear side (the side opposite to the operating side) relative to the center P of the mold 32.

[0193] Therefore, the mold 31 does not rotate with a certain stopper 82 as a fulcrum, and the mold 32 does not rotate with a certain stopper 82 as a fulcrum. Therefore, even if the clamps 42 of all the hydraulic clamp devices 40 are in the retreated position for some reason, the molds 31 and 32 are more stably held by the hydraulic clamp device 40 and the stopper 82 on the lower side.

[0194] The above-described prevention of the rotation of the molds 31 and 32 can be achieved even when the gas pressure stopper device 80 is moved to another position. For example, even if at least one of the gas pressure stopper devices 80 is moved to the front upper part and the rear upper part of the movable platen 21, the rotation of the mold 31 can be prevented. Similarly, even if at least one of the gas pressure stopper devices 80 is moved to the front upper part and the rear upper part of the fixed platen 22, the rotation of the mold 32 can be prevented.

[0195] In addition, Fig.15A and Fig. 15B In the figure, the pneumatic lines (dashed lines) show the gas pressure stopper devices 80 moved to the upper front and upper rear parts of the fixed plate 22 and the movable plate 21, but the positions of the gas pressure stopper devices 80 are not limited to the positions shown in the figure.

[0196] The invention proposed by the inventors has been specifically described above based on the embodiments, but the present invention is not limited to the above embodiments and can be modified in various ways without departing from the gist of the invention. For example, the air stopper device 80 can be replaced with a double-acting cylinder including a module provided with a cylinder tube.

[0197] In addition, the pneumatic stopper device 80 may be replaced with a double-acting cylinder or a single-acting cylinder having an urging member (for example, a coil spring) for urging the stopper 82 toward the advanced position.

[0198] The hydraulic clamp device 40 may be a single-acting type instead of a double-acting type. In addition, the hydraulic clamp device 40 may be replaced by a pneumatic clamp device, an electric clamp device, etc., provided that the hydraulic clamp device 40 is driven by a driving source different from the pneumatic stopper device 80 .

[0199] The mold opening and closing cylinder 25 of the molding machine 1A can be replaced with the mold opening and closing mechanism 110 of the molding machine 1B, other similar mechanisms, etc. The number of the hydraulic clamp devices 40 can be increased or decreased as appropriate.

[0200] The mold clamping device may be provided with a rotating table capable of carrying a plurality of molds. In this case, multi-color molding can be performed by injecting molding materials from a plurality of injection devices. The mold clamping device may be configured to perform various moldings such as insert molding, foam molding, fiber-reinforced resin molding, and mold sliding molding.

[0201] The first mechanical clamp and the second mechanical clamp may be driven by different driving sources of the same type. For example, the first mechanical clamp and the second mechanical clamp may be driven by different hydraulic pumps.

[0202] The present invention can also be applied to a mold clamping device other than a mold clamping device of an injection molding machine that is configured to supply molding material to a mold installed on a fixed plate and installed on a movable plate in an open mold state from an extruder, other material supplying devices, etc., and then close the mold to perform compression molding.

Claims

1. A mold clamping device, characterized in that: include: a first mold mounting plate and a second mold mounting plate, wherein the first mold mounting plate and the second mold mounting plate are arranged opposite to each other and move relative to each other in an approaching direction and a separating direction; a first mechanical fixture capable of securing the first mold relative to the first mold mounting plate; a second mechanical fixture capable of securing the second mold relative to the second mold mounting plate; as well as a stopper capable of retaining the first mold relative to the first mold mounting plate, The first mechanical clamp and the second mechanical clamp and the stopper are driven by separate driving sources independent of each other.

2. The mold clamping device according to claim 1, characterized in that: The first mechanical clamp and the second mechanical clamp are driven by hydraulic pressure, The stopper is actuated by air pressure.

3. The mold clamping device according to claim 1, characterized in that: The stopper comprises a retaining surface, When the first mold is fixed by the first mechanical clamp, at least the holding surface of the stopper is separated from the first mold, When the first mold is not fixed by the first mechanical clamp, at least the holding surface of the stopper abuts against the first mold, and the first mold is held.

4. The mold clamping device according to claim 1, characterized in that: The mold clamping device has a plurality of the stoppers, The plurality of stoppers include a pair of the stoppers offset from each other with respect to a center of the first mold.

5. The mold clamping device according to claim 1, characterized in that: The first mechanical clamp is capable of reciprocating between an advanced position for fixing the first mold and a retreated position for being separated from the first mold relative to the advanced position. The second mechanical clamp is capable of reciprocating between an advanced position for fixing the second mold and a retreated position for being separated from the second mold relative to the advanced position. The stopper is reciprocatable between an advanced position for holding the first mold and a retreated position for being separated from the first mold compared to the advanced position. The mold clamping device comprises: a clamp position detection unit that detects positions of the first mechanical clamp and the second mechanical clamp; and A stopper position detection unit detects a position of the stopper.

6. The mold clamping device according to claim 1, characterized in that: The first mold mounting plate is arranged above the second mold mounting plate in the vertical direction. The first mechanical clamp fixes the first mold to a mold mounting surface of the first mold mounting plate that is opposite to the second mold mounting plate in a vertical direction. The stopper holds the first mold from a lower side of the first mold in a vertical direction.

7. A method for controlling a mold clamping device, characterized in that: The clamping device comprises: a first mold mounting plate and a second mold mounting plate, the first mold mounting plate and the second mold mounting plate are arranged opposite to each other and move relative to each other in a direction of approaching each other and in a direction of separating each other; a first mechanical fixture capable of securing the first mold relative to the first mold mounting plate; a second mechanical clamp capable of securing a second mold relative to the second mold mounting plate; and a stopper capable of retaining the first mold relative to the first mold mounting plate, The first mechanical clamp is capable of reciprocating between an advanced position for fixing the first mold and a retreated position for being separated from the first mold relative to the advanced position. The second mechanical clamp is capable of reciprocating between an advanced position for fixing the second mold and a retreated position for being separated from the second mold relative to the advanced position. The stopper is reciprocatable between an advanced position for holding the first mold and a retreated position for being separated from the first mold compared to the advanced position. When it is detected that the first mechanical clamp and the second mechanical clamp move to the respective advanced positions and when it is detected that the stopper moves to the advanced position of the stopper, relative movement of the first mold mounting platen and the second mold mounting platen is permitted.

8. The control method of the mold clamping device according to claim 7, characterized in that: The first mechanical clamp and the second mechanical clamp are driven by hydraulic pressure, When it is detected that the first mechanical clamp and the second mechanical clamp move to their respective forward positions, when it is detected that the pressure of the working oil supplied to the first mechanical clamp and the second mechanical clamp exceeds a threshold, and when it is detected that the stopper moves to the forward position of the stopper, relative movement of the first mold mounting plate and the second mold mounting plate is allowed.

Images