Mold for injection molding machine

Abstract

A mold (10) for an injection molding machine has a fixed-side cassette mold (21) held by a fixed-side base mold (18) of the injection molding machine, and a movable-side cassette mold (22) held by a movable-side base mold (19). The movable-side base mold (19) is provided with a movable-side clamp rod (50) that clamps and unclamps the movable-side cassette mold (22) held by the movable-side base mold (19). A lock lever (61) that locks and unlocks the fixed-side cassette mold (21) is rotatably supported by the movable-side cassette mold (22). The lock lever (61) is rotated from the lock position to the unlock position by the clamp operation of the movable-side clamp rod (50).

Description

Mold for injection molding machine

[0001] The technology disclosed in this specification relates to a mold for an injection molding machine.

[0002] A conventional mold exchange device is disclosed, for example, in Japanese Patent Application Laid-Open No. 2021-142717. The device includes a first mold, a second mold, and an exchangeable mold. The exchangeable mold includes a mold-side switching mechanism (lock pin) that switches between a connected state and a disconnected state of the first mold and the second mold. The mold exchange device further includes a first master mold that presses the first mold toward the second mold, and a second master mold that presses the second mold toward the first mold. An intermediate master mold is disposed so as to be displaceable between the first master mold and the second master mold. The intermediate master mold accommodates at least a portion of the exchangeable mold. The mold exchange device further includes a first master mold-side switching mechanism that switches between a connected state and a disconnected state of the first master mold and the intermediate master mold. The mold exchange device further includes a second master mold-side switching mechanism that switches between a connected state and a disconnected state of the second master mold and the intermediate master mold. The replaceable mold corresponds to the "cassette mold" in this specification, and each mother mold corresponds to the "base mold" in this specification.

[0003] According to JP 2021-142717 A, when attaching or detaching a cassette mold, a switching operation of the mold-side switching mechanism, a switching operation of the first mother mold-side switching mechanism, and a switching operation of the second mother mold-side switching mechanism are required. Therefore, the labor required for attaching or detaching the cassette mold is large. Furthermore, the mold of this device has an intermediate mother mold, a first mother mold-side switching mechanism, and a second mother mold-side switching mechanism to hold an interchangeable mold between the first mother mold and the second mother mold. This results in an increased mold size. Note that JP 2021-142717 A does not include a device for detachably holding the first mold to the first mother mold, or a device for detachably holding the second mold to the second mother mold.

[0004] There has been a need for a technology that can reduce the number of steps required to attach and detach cassette molds and also reduce the size of molds for injection molding machines.

[0005] According to one feature of the present disclosure, a mold for an injection molding machine molds a molded product using a cassette mold having a fixed cassette mold held by a fixed base mold of an injection molding machine and a movable cassette mold held by a movable base mold. A clamp rod is provided in one of the base molds, either the fixed base mold or the movable base mold, and is movable forward and backward, for clamping and unclamping one of the cassette molds held by the base mold. A lock lever is rotatably supported on one of the cassette molds, for locking and unlocking the other cassette mold. The lock lever is rotated from a locked position to an unlocked position by the clamping action of the clamp rod.

[0006] The lock lever, which is in the locked position to lock one cassette mold to the other, is rotated to the unlocked position by the clamping action of the clamp rod when clamping one cassette mold to one base mold. In other words, the lock lever can be unlocked by utilizing the clamping action of the clamp rod. This reduces the man-hours required for the installation and removal of cassette molds. In addition, a dedicated device for operating the lock lever is not required, allowing the mold for the injection molding machine to be made smaller.

[0007] According to another feature of the present disclosure, the clamp rod has a tapered end portion that is axially engageable with and disengageable from an engagement hole formed in the one cassette mold, and the one cassette mold is clamped to the one base mold by sliding contact resulting from engagement of the tapered end portion with the engagement hole.

[0008] The tapered end of the clamp rod can be used to slide against the mating hole of one of the cassette dies to fasten the one of the base dies, thereby securely clamping the one of the cassette dies to the one of the base dies.

[0009] According to another feature of the present disclosure, a stopper mechanism is provided between the one base mold and the clamp rod to restrict the amount of movement of the clamp rod in the advancing direction relative to the engagement hole.

[0010] The amount of movement of the clamp rod in the forward direction can be restricted by the stopper mechanism, thereby preventing the clamp rod from applying excessive load to one of the cassette dies.

[0011] According to another feature of the present disclosure, the lock lever has a hook portion that is releasably engaged with a hook portion formed on the other cassette mold, the hook portion has an undercut portion formed therein, and the hook portion has a retaining protrusion that engages with the undercut portion.

[0012] The engagement between the undercut portion of the hook portion and the retaining projection of the latch portion can prevent the lock lever from rotating in the latch release direction.

[0013] According to another feature of the present disclosure, the one cassette type is provided with a lever biasing mechanism that always biases the lock lever to the lock position.

[0014] As the clamp rod is released, the lock lever is biased to the lock position by the lever biasing mechanism, thereby locking one cassette mold to the other cassette mold.

[0015] FIG. 1 is a front view of a mold for an injection molding machine according to one embodiment; FIG. 2 is a rear view of a mold for an injection molding machine; FIG. 3 is a right side view of a cassette mold changing device; FIG. 4 is a plan sectional view of the periphery of a lock lever of a cassette mold; FIG. 5 is a plan sectional view of the periphery of the lock lever in a locked state; FIG. 6 is a plan sectional view of the periphery of the lock lever in an unlocked state; FIG. 7 is an enlarged view of the periphery of a hook portion of the lock lever; FIG. 8 is a view showing a stopper groove of a movable clamp rod; FIG. 9 is a view showing a lock lever; FIG. 10 is a view showing a hook member; FIG. 11 is a schematic view of a mold for an injection molding machine in a mold open state; FIG. 12 is a schematic view of a mold for an injection molding machine in a mold clamped state; FIG. 13 is a schematic view showing a work process related to the attachment and detachment of a cassette mold; FIG. 14 is a schematic view showing a work process related to the attachment and detachment of a cassette mold; FIG. 15 is a schematic view showing a work process related to the attachment and detachment of a cassette mold;

[0016] An embodiment for carrying out the technology disclosed in this specification will be described below with reference to the drawings. For convenience of explanation, the up, down, left, and right directions are defined based on the front view of Figure 1. Figures 1 to 3 are schematic diagrams.

[0017] (Outline of Mold for Injection Molding Machine) As shown in Figure 1, a mold 10 for an injection molding machine is installed on a pedestal 11 extending in the left-right direction of the injection molding machine M. A right support portion 12 and a left support portion 13 are arranged on the pedestal 11 at a predetermined distance. A space 14 that is open upward is formed between the right support portion 12 and the left support portion 13. A cassette mold changer 30 is provided in the space 14.

[0018] A fixed platen 15 is installed on the right support part 12. A movable platen 16 is installed on the left support part 13 so that it can move back and forth in the left-right direction. The injection molding machine M is equipped with a mold clamping device including the fixed platen 15 and the movable platen 16, as well as a control device 17 that controls the injection device and each device. The control device 17 is also used to control each device related to the injection molding machine mold 10 and the cassette mold change device 30.

[0019] A fixed base mold 18 is attached to the fixed platen 15. A movable base mold 19 is attached to the movable platen 16. A cassette mold 20 is disposed between the fixed base mold 18 and the movable base mold 19.

[0020] The cassette mold 20 has a fixed cassette mold 21 and a movable cassette mold 22. In Fig. 1, the cassette mold 20 is shown positioned at an intermediate position (a loading / unloading position of the cassette mold 20) between the fixed base mold 18, which is at the maximum separation position, and the movable base mold 19. A molding space (cavity) 23 having a shape corresponding to a desired molded product is formed between the fixed cassette mold 21 and the movable cassette mold 22. The movable cassette mold 22 is provided with an ejector mechanism 25 for pushing the molded product out of the molding space 23.

[0021] When molding a molded product, the fixed-side cassette mold 21 is removably held in a state where it is fitted into a fitting recess 18a formed in the fixed-side base mold 18. The movable-side cassette mold 22 is removably held in a state where it is fitted into a fitting recess 19a formed in the movable-side base mold 19. In this state, the fixed-side cassette mold 21 and the fixed-side base mold 18 function as a fixed mold 26, and the movable-side cassette mold 22 and the movable-side base mold 19 function as a movable mold 27.

[0022] With the movable mold 27 clamped to the fixed mold 26 (see FIG. 12), molten resin is injected into the molding space 23 at high pressure by an injection device. The molten resin in the molding space 23 is then cooled and solidified to obtain a molded product. The movable mold 27 is then opened (see FIG. 11), and the molded product is removed. The mold opening position of the movable platen 16 is set to a position to the right of the maximum separation position (see FIG. 1).

[0023] The cassette mold 20 is replaced depending on the molded product to be molded. When the cassette mold 20 is replaced, the fixed cassette mold 21 and the movable cassette mold 22 are integrally connected. This connection is released when the molded product is molded.

[0024] (Overview of the Cassette Mold Changing Device 30) As shown in FIG. 1 , the cassette mold changing device 30 includes a machine base 31 installed on a pedestal 11. The machine base 31 is formed in the shape of a rectangular box using a bar-shaped material such as steel. A shifter cylinder 33 is supported horizontally at the upper left end of the machine base 31 with its axial direction extending left-right. A roughly rectangular plate-shaped shifter 32 is connected horizontally to the tip of a rod 33a protruding to the right from the shifter cylinder 33. The shifter 32 is moved back and forth left-right by the operation of the shifter cylinder 33 (see the two-dot chain line 32 in FIG. 1 ). A support device (not shown) is provided between the machine base 31 and the shifter 32 to guide and support the shifter 32 so that it can move left-right in a horizontal position.

[0025] A lifter cylinder 35 is supported below the center of the shifter 32 in a suspended state with its axial direction extending vertically. A rod 35a projects from the lifter cylinder 35 above the shifter 32, and a substantially rectangular plate-shaped lifter 36 is connected to the tip of the rod 35a in a horizontal position. The lifter 36 is configured so that a cassette mold 20 can be placed thereon. The lifter 36 is raised and lowered by operation of the lifter cylinder 35 (see the two-dot chain line 36 in FIG. 1). A guide device (not shown) is provided between the shifter 32 and the lifter 36 to guide the lifter 36 so that it can be raised and lowered horizontally.

[0026] An electric, hydraulic, or pneumatic drive source can be used as the drive means for the shifter cylinder 33 and the lifter cylinder 35. The operation of both cylinders 33, 35 (specifically, the drive source) is controlled by the control device 17.

[0027] 3, the lifter 36 is provided with left and right roller conveyors 38. The roller conveyors 38 support the cassette mold 20 placed on the lifter 36 so that the cassette mold 20 can be moved in the front-rear direction. When replacing the cassette mold 20, for example, a hand-pushed cassette mold transport cart is used to carry the cassette mold 20 into and out of the lifter 36.

[0028] (Fixed-side clamp rod) As shown in Figure 5, a round-bar-shaped fixed-side clamp rod 40 that clamps and unclamps the fixed-side cassette mold 21 to the fixed-side base mold 18 is provided on the fixed-side base mold 18 so as to be movable back and forth in a horizontal position. The fixed-side clamp rod 40 is inserted into a guide hole 18b formed in the fixed-side base mold 18 so as to be movable in the axial direction (front and back direction). The fixed-side clamp rod 40 is moved back and forth by the extension and contraction action of a fixed-side clamp cylinder 45 (see Figure 1).

[0029] Three fixed-side clamp cylinders 45 are arranged: one at the bottom of the front side of the fixed-side base mold 18 (see FIG. 1 ) and two at the top and bottom of the rear side (see FIG. 2 ). A hydraulic drive source can be used as the drive means for the fixed-side clamp cylinders 45. The fixed-side clamp cylinders 45 are controlled by the control device 17. Of the three fixed-side clamp cylinders 45, when the fixed-side clamp rod 40 performs a clamping operation (advance operation), the two rear cylinders 45 are simultaneously activated before the front cylinder is activated. When the fixed-side clamp rod 40 performs an unclamping operation (retraction operation), the front cylinder is simultaneously activated before the two rear cylinders are simultaneously activated. Below, the front fixed-side clamp rod 40 will be described, and a description of the rear fixed-side clamp rod 40 and its related configuration will be omitted.

[0030] As shown in Figure 5, the tip of the fixed clamp rod 40 is formed with a tapered end 41 having a slope 42 that is beveled over approximately half of the tip surface. The cross section of the tapered end 41 is formed into a D-shape with the cross-sectional area gradually decreasing toward the tip. The slope 42 faces away from the movable base mold 19 (to the right in Figure 5).

[0031] A fixed-side engagement hole 21a corresponding to the tapered end 41 of the fixed-side clamp rod 40 is formed in the front surface of the fixed-side cassette mold 21. The fixed-side engagement hole 21a is D-shaped so that the tapered end 41 can be engaged and disengaged (see FIG. 1). The straight portion of the fixed-side engagement hole 21a corresponds to the slope 42 of the tapered end 41. By engaging (inserting) the tapered end 41 into the fixed-side engagement hole 21a, the fixed-side cassette mold 21 is clamped (held) in a state where it is tightened to the right on the fixed-side base mold 18. By removing the tapered end 41 from the fixed-side engagement hole 21a (see the two-dot chain line 41 in FIG. 5), the clamping of the fixed-side cassette mold 21 to the fixed-side base mold 18 is released.

[0032] (Movable-side clamp rod) As shown in Figure 5, a round bar-shaped movable-side clamp rod 50 that clamps and unclamps the movable-side cassette mold 22 to the movable-side base mold 19 is provided on the movable-side base mold 19 in a horizontal position so as to be movable back and forth in the front-to-rear direction. The movable-side clamp rod 50 is inserted into a guide hole 19b formed in the movable-side base mold 19 so as to be movable in the axial direction (front-to-rear direction). The movable-side clamp rod 50 is moved back and forth by the extension and retraction action of a movable-side clamp cylinder 55 (see Figure 1).

[0033] Three movable clamp cylinders 55 are arranged: one at the bottom front of the movable base mold 19 (see FIG. 1) and two at the top and bottom rear (see FIG. 2). A hydraulic drive source can be used as the drive means for the movable clamp cylinders 55. The movable clamp cylinders 55 are controlled by the control device 17. The three movable clamp cylinders 55 are operated simultaneously when the movable clamp rod 50 performs a clamping operation (advancing operation) and a clamp unclamping operation (retreating operation). The following describes the front movable clamp rod 50, and a description of the rear movable clamp rod 50 and related configuration will be omitted.

[0034] 5, the movable clamp rod 50 has basically the same shape as the fixed clamp rod 40, and is formed at its tip with a tapered end 51 having a slope 52. The slope 52 faces away from the fixed base mold 18 (to the left in FIG. 5).

[0035] A movable side engagement hole 22a corresponding to the tapered end 51 of the movable side clamp rod 50 is formed in the front surface of the movable side cassette mold 22. The movable side engagement hole 22a is formed in a D-shape that allows the tapered end 51 to be engaged and disengaged. The straight portion of the movable side engagement hole 22a corresponds to the slope 52 of the tapered end 51. By engaging (inserting) the tapered end 51 into the movable side engagement hole 22a, the movable side cassette mold 22 is clamped (held) to the movable side base mold 19 in a tightened state toward the left (see FIG. 6). By removing the tapered end 51 from the movable side engagement hole 22a (see FIG. 5), the clamping of the movable side cassette mold 22 to the movable side base mold 19 is released.

[0036] In Figures 1 and 2, the fixed side clamp cylinder 45 and the fixed side engagement hole 21a, and the movable side clamp cylinder 55 and the movable side engagement hole 22a are arranged in positions that are offset vertically, but for convenience, Figures 5 and 6 show them arranged on the same plane.

[0037] 4, two sets of locking mechanisms 60 are arranged symmetrically in the front and rear of the movable cassette mold 22. The front locking mechanism 60 will be described below, and a description of the rear locking mechanism 60 and its related configuration will be omitted.

[0038] The locking mechanism 60 includes a locking lever 61 that locks and unlocks the fixed cassette mold 21 to the movable cassette mold 22, and a hook member 65 to which the locking lever 61 is hooked. The locking lever 61 is housed in a recess 22b that is continuous with the movable engagement hole 22a of the movable cassette mold 22 and extends horizontally toward the fixed cassette mold 21. The locking lever 61 is supported on the movable cassette mold 22 via a support shaft 64 so as to be rotatable in the front-rear direction. One end (left end) of the locking lever 61 is formed with an abutment portion 62 that abuts against the tip of the movable clamp rod 50. The other end (right end) of the locking lever 61 is formed with a hook portion 63 that protrudes from the recess 22b and has an L-shaped bent tip.

[0039] As shown in Figure 7, the hook member 65 is provided in a recess 21b formed in the fixed cassette mold 21. The hook member 65 is fastened to the fixed cassette mold 21 with a bolt 68. A hook portion 63 can enter and exit the recess 21b. The hook member 65 is arranged so that the hook portion 63 can be hooked (see the two-dot chain line 63 in Figure 7).

[0040] An undercut portion 63a is formed in the hook portion 63. Accordingly, an engaging protrusion 63b is formed at the tip of the hook portion 63 (see FIG. 9). Meanwhile, a mountain-shaped retaining protrusion 65a that engages with the undercut portion 63a is formed in the hook member 65. Accordingly, an engaging recess 65b that engages with the engaging protrusion 63b is formed in the hook member 65 (see FIG. 10). When the hook portion 63 is hooked to the hook member 65, the undercut portion 63a engages with the retaining protrusion 65a, and the engaging protrusion 63b engages with the engaging recess 65b (see the two-dot chain line 63 in FIG. 7).

[0041] 5, the movable cassette mold 22 is provided with a lever biasing mechanism 70 that constantly biases the lock lever 61 toward the locked position. The lever biasing mechanism 70 is provided behind the abutment portion 62 of the lock lever 61 and is disposed in a stepped hole 22c that is continuous with the recess 22b of the movable cassette mold 22. The lever biasing mechanism 70 includes a pushing pin 71 that abuts against the abutment portion 62 of the lock lever 61, a coil spring 72 that biases the pushing pin 71, and a retaining plate 73 that prevents the pushing pin 71 from coming out.

[0042] The retaining plate 73 is attached to the stepped surface of the stepped hole 22c with bolts 74. The pushing pin 71 and coil spring 72 are housed in the bottom (rear portion) of the stepped hole 22c. A tip 71a of the pushing pin 71 protrudes from a hole 73a formed in the retaining plate 73. The pushing pin 71 is formed with a flange portion 71b having an outer diameter larger than the inner diameter of the hole 73a. The flange portion 71b abuts against the retaining plate 73, thereby preventing the pushing pin 71 from coming out.

[0043] The lock lever 61 is biased to the lock position by the coil spring 72 via the pushing pin 71, thereby locking (connecting) the fixed cassette mold 21 to the movable cassette mold 22. Furthermore, as shown in Figure 6, when the lock lever 61 is rotated from the locked position to the unlocked position by the clamping operation (advancement) of the movable clamp rod 50, the pushing pin 71 is pushed in against the bias of the coil spring 72.

[0044] 6, a stopper mechanism 80 that restricts the amount of movement of the movable clamp rod 50 in the advancing direction relative to the movable engagement hole 22a is provided between the movable base mold 19 and the movable clamp rod 50. The stopper mechanism 80 is composed of a stopper pin 81 provided on the movable base mold 19 and a stopper groove 83 formed in the movable clamp rod 50.

[0045] The stopper pin 81 is implanted in the movable base mold 19 so as to be perpendicular to the movable clamp rod 50 and so that its tip (right end) protrudes into the guide hole 19b. The stopper groove 83 is formed in the slope 52 of the tapered end 51 of the movable clamp rod 50. As shown in Figure 8, the stopper groove 83 is formed in the shape of an elongated groove extending in the axial direction toward the base end of the tapered end 51. The end face on the deeper side of the stopper groove 83 serves as a stopper surface 83a.

[0046] As shown in Fig. 5, when the movable clamp rod 50 is in the clamp release position (retracted position), the tip of the stopper pin 81 is located at a position away from the stopper surface 83a of the stopper groove 83. Furthermore, as shown in Fig. 6, when the movable clamp rod 50 is in the clamped position (advanced position), the stopper surface 83a of the stopper groove 83 approaches or abuts against the stopper pin 81. The abutment of the stopper surface 83a of the stopper groove 83 against the stopper pin 81 restricts the amount of movement of the movable clamp rod 50 in the advancing direction.

[0047] The fixed-side base mold 18 corresponds to the "other base mold" in this specification. The movable-side base mold 19 corresponds to the "one base mold" in this specification. The fixed-side cassette mold 21 corresponds to the "other cassette mold" in this specification. The movable-side cassette mold 22 corresponds to the "one cassette mold" in this specification.

[0048] (Procedure for Replacing the Cassette Mold 20) The procedure for replacing the cassette mold 20 is broadly divided into a demolding process in which the cassette mold 20 is removed from the fixed base mold 18 and the movable base mold 19, and a demolding process in which the cassette mold 20 is attached to the fixed base mold 18 and the movable base mold 19. Unless otherwise specified, it is assumed that the control device 17 (see FIG. 1) controls each device in the replacement of the cassette mold 20.

[0049] (Mold Unloading Process) Assume now that the injection molding machine mold 10 has moved from the mold open state after molding (see FIG. 11) to the mold clamped state (see FIG. 12). In this mold clamped state, as shown in FIG. 6, the fixed-side cassette mold 21 is clamped to the fixed-side base mold 18 by the fixed-side clamp rod 40. The movable-side cassette mold 22 is clamped to the movable-side base mold 19 by the movable-side clamp rod 50. In addition, the lock lever 61 is unlocked.

[0050] In this state, the clamping of the movable cassette mold 22 by the movable clamp rod 50 is released (see FIG. 13). Then, as shown in FIG. 5, as the clamping of the movable clamp rod 50 is released, the lock lever 61 is rotated to the lock position by the biasing force of the lever biasing mechanism 70, thereby locking, i.e., integrating, the fixed cassette mold 21 with the movable cassette mold 22. In FIG. 13, the abutment portion 62 of the lock lever 61 is exposed.

[0051] Next, the movable base mold 19 is moved to the mold opening position (see FIG. 14), whereby the movable base mold 19 is separated from the cassette mold 20.

[0052] Next, the cassette mold 20 is received by the lifter 36 which is raised from directly below the movable cassette mold 22 (see FIG. 15). Next, the clamping of the fixed cassette mold 21 by the fixed clamp rod 40 is released (see FIG. 16).

[0053] Next, the movable base mold 19 is moved to the maximum retracted position (full stroke position), and the lifter 36 is moved (to the left) to the loading / unloading position for the cassette mold 20 (see FIG. 17). At this time, the rod 28a of the ejection cylinder 28 provided on the fixed base mold 18 is protruded (see the two-dot chain line 28a in FIG. 17). This pushes the cassette mold 20 out of the fixed base mold 18. Thereafter, the rod 28a of the ejection cylinder 28 is retracted to the standby position (see the solid line 28a in FIG. 17). Note that the ejection cylinder 28 is omitted from FIGS. 11 to 16.

[0054] The cassette mold 20 on the lifter 36 is then transferred by the worker to a cassette mold transport cart and stored in a predetermined storage location. In this way, the removal of the cassette mold 20, i.e., the demolding, is completed.

[0055] (Step of lifting the cassette mold 20) First, the cassette mold 20 is transferred from the storage location to a cassette mold transport cart by an operator and is carried onto the lifter 36 at the carry-in / out position (see FIG. 17). Next, the movable base mold 19 is moved to the mold opening position, and the fixed cassette mold 21 of the cassette mold 20 is fitted into the fixed base mold 18 by the movement of the lifter 36 (see FIG. 16).

[0056] Next, the fixed-side cassette mold 21 is clamped to the fixed-side base mold 18 by the fixed-side clamp rod 40 (see FIG. 15). After that, the lifter 36 is moved downward (see FIG. 14). Next, the movable-side base mold 19 is moved to the mold clamping position and fitted into the movable-side cassette mold 22 of the cassette mold 20 (see FIG. 13).

[0057] Next, the movable side cassette mold 22 is clamped to the movable side base mold 19 by the movable side clamp rod 50 (see FIG. 12). As the movable side clamp rod 50 clamps, the lock lever 61 is rotated to the unlock position against the bias of the lever biasing mechanism 70, thereby releasing the lock between the movable side cassette mold 22 and the fixed side cassette mold 21 (see FIG. 6). This allows the movable mold 27 to be opened relative to the fixed mold 26 (see FIG. 11). In this way, the installation of the cassette mold 20, i.e., the mold lifting, is completed. After this, the molding process for the molded product begins.

[0058] (Functions and Effects of the Embodiment) According to the mold 10 for an injection molding machine described above, the lock lever 61, which is in the lock position where it locks the fixed cassette mold 21 to the movable cassette mold 22, is rotated to the unlock position by the clamping action of the clamp rod when clamping the movable cassette mold 22 to the movable base mold 19. In other words, the lock lever 61 can be unlocked by utilizing the clamping action of the clamp rod. This reduces the number of steps required for the installation and removal of the cassette mold 20. Furthermore, a dedicated device for operating the lock lever 61 is not required, and the mold 10 for an injection molding machine can be made smaller.

[0059] Furthermore, the movable cassette mold 22 can be fastened to the movable base mold 19 by utilizing the sliding contact of the tapered end 41 of the movable clamp rod 50 with the movable engagement hole 22a of the movable cassette mold 22. This allows the movable cassette mold 22 to be fixedly clamped to the movable base mold 19.

[0060] Furthermore, the amount of movement of the movable clamp rod 50 in the advancing direction can be restricted by the stopper mechanism 80. This makes it possible to prevent the movable clamp rod 50 from applying an excessive load to the movable cassette mold 22.

[0061] Furthermore, the engagement between the undercut portion 63a of the hook portion 63 of the lock lever 61 and the retaining protrusion 65a of the latch member 65 can prevent the lock lever 61 from rotating in the latch release direction.

[0062] In addition, as the movable side clamp rod 50 undergoes an unclamping operation (retraction), the lock lever 61 is urged to the lock position by the lever urging mechanism 70, thereby locking the fixed side cassette mold 21 to the movable side cassette mold 22.

[0063] [Other Embodiments] The technology disclosed in this specification is not limited to the embodiments and can be embodied in various other forms. For example, the injection molding machine mold 10 is not limited to the resin injection molding machine M exemplified in the embodiments, but may also be applied to an injection molding machine M for a meltable metal material such as aluminum. Furthermore, in the embodiments, the movable base mold 19 is one base mold and the fixed base mold 18 is the other base mold, but the fixed base mold 18 may be one base mold and the movable base mold 19 may be the other base mold.

[0064] Furthermore, the fixed-side clamp cylinder 45 and / or the movable-side clamp cylinder 55 are not limited to hydraulic drive sources, but may also be electric, pneumatic, or other drive sources. Furthermore, the tapered end portion 41 of the fixed-side clamp rod 40 and / or the tapered end portion 51 of the movable-side clamp rod 50 are not limited to having a shape with an inclined surface 42, 52, but may also have a tapered shape such as a truncated cone or a truncated pyramid. The shape of the fixed-side engagement hole 21a and / or the movable-side engagement hole 22a may also be changed depending on the shape of the tapered end portions 51, 52. Furthermore, the number of fixed-side clamp rods 40 and / or movable-side clamp rods 50 may be increased or decreased.

Claims

1. A mold for an injection molding machine, comprising: a fixed cassette mold held by a fixed base mold of an injection molding machine; a movable cassette mold held by a movable base mold; a clamp rod movably mounted on either the fixed base mold or the movable base mold, for clamping and unclamping one of the cassette molds held by one of the base molds; and a lock lever rotatably supported on one of the cassette molds, for locking and unlocking the other cassette mold, wherein the lock lever is rotated from a locked position to an unlocked position by the clamping action of the clamp rod.

2. A mold for an injection molding machine as claimed in claim 1, wherein the clamp rod has a tapered end portion that can be axially engaged with and disengaged from an engagement hole formed in one of the cassette molds, and the one of the cassette molds is clamped to the one of the base molds by sliding contact resulting from the engagement of the tapered end portion with the engagement hole.

3. A mold for an injection molding machine as described in claim 2, wherein a stopper mechanism is provided between the one base mold and the clamp rod to restrict the amount of movement of the clamp rod in the advancing direction relative to the engagement hole.

4. A mold for an injection molding machine according to any one of claims 1 to 3, wherein the lock lever has a hook portion that can be detachably hooked onto a hook portion formed on the other cassette mold, an undercut portion is formed in the hook portion, and a retaining projection that engages with the undercut portion is formed in the hook portion.

5. A mold for an injection molding machine according to any one of claims 1 to 4, wherein one of the cassette molds is provided with a lever biasing mechanism that always biases the lock lever to the locked position.

Images