Rotating device for double injection mold

Abstract

The present invention relates to a rotating device for a double injection mold, and more specifically, to a rotating device for rotating a mold for double injection. The present invention has been devised to solve the above-mentioned problems and aims to provide a rotating device for a double injection mold that rotates the entire second mold part, which is mated with the first mold part of the double injection mold, thereby having a simple structure and high compatibility with easy application to various double injection molds. In addition, the present invention aims to provide a rotary device for a double injection mold with high operation efficiency by providing a rotation limiting means that limits rotation when the rotary table is rotated by a set angle. Furthermore, the present invention aims to provide a rotary device for a double injection mold that can increase the durability of the drive unit by preventing the impact generated during the joining or separation of the first and second mold parts from being transmitted to the drive shaft of the rotary drive motor.

Description

Technology Field

[0001] The present invention relates to a rotating device for a double injection mold, and more specifically, to a rotating device for rotating a mold for double injection molding. Background Technology

[0002] Generally, double injection is a method of molding a product composed of two different resins or two resins of different colors by sequentially injecting two different resins or molten synthetic resins of different colors into a single mold.

[0003] The injection mold for such double injection has two injection sections so that two types of resins can be injected, and is configured to include a first cavity into which the first resin is injected, and a second cavity into which the second resin is injected to inject a second product into the first product formed in the first cavity.

[0004] This dual injection molding has fewer shape constraints, a wider range of product applications, and allows for design diversification. In addition, since two types of resin are injected simultaneously, unlike conventional methods where two types of injection molded parts had to be injected separately and then fused or painted, production efficiency is increased, which can reduce production costs and increase productivity.

[0005] A double injection mold is typically composed of a fixed mold and a movable mold for mold closing and opening. The fixed mold includes a resin injection unit capable of injecting molten resin into a cavity. The resin injection unit includes a first injection unit and a second injection unit, and is positioned to penetrate the fixed mold and connect to the cavity below.

[0006] Generally, although not illustrated, the movable mold includes a movable mold plate, a core seated on the movable mold plate, a shaft that moves and rotates the core linearly from the movable mold plate, and a bushing that supports the shaft.

[0007] The above-described core is configured to form a first cavity and a second cavity into which resin is injected when the fixed-side mold and the movable-side mold are joined. The first cavity is a space where the first injection-molded product is molded, and the second cavity is a space where the second injection-molded product is molded, having a shape corresponding to the outer shape of the injection-molded product.

[0008] The shaft is configured to move a first injection molded product formed by a first cavity to a second cavity, and penetrates the movable mold plate to be coupled to the lower side of the core. Additionally, the bush serves to prevent wear caused by friction, etc., while the shaft moves within the movable mold.

[0009] This structure has the disadvantage of low compatibility because the structure of the movable mold is complex, and it is difficult to change or replace the movable mold to mold various injection products. Prior art literature

[0010] Korean Patent Publication No. 10-2020-0136577: Injection molding machine equipped with an improved double injection turntable The problem to be solved

[0011] The present invention has been devised to solve the above-mentioned problems and aims to provide a rotating device for a double injection mold that rotates the entire second mold part, which is mated with the first mold part of the double injection mold, thereby having a simple structure and high compatibility with easy application to various double injection molds.

[0012] In addition, the present invention aims to provide a rotary device for a double injection mold with high operation efficiency by providing a rotation limiting means that limits rotation when the rotary table is rotated by a set angle.

[0013] Furthermore, the present invention aims to provide a rotary device for a double injection mold that can increase the durability of the drive unit by preventing the impact generated during the joining or separation of the first and second mold parts from being transmitted to the drive shaft of the rotary drive motor. means of solving the problem

[0014] A rotary device for a double injection mold according to the present invention for achieving the above objective comprises: a rotary table having a second mold part mounted on one side that is coupled with a first mold part to form a first cavity for molding a first injection product and a second cavity for molding a second injection product on the first injection product; a support table that supports the rotation of the rotary table; a power transmission shaft that rotatably penetrates the center of the support table and is coupled to the center of the rotary table; a rotary drive motor for rotating the power transmission shaft; a sensing unit that detects the rotation angle of the rotary table and the power transmission shaft; and a rotation limiting means that limits the rotation of the rotary table when the rotary table is rotated by a set angle while the second mold part is separated from the first mold part after molding the first injection product.

[0015] The above-described sensing unit comprises first and second limit switches symmetrically arranged on one side of the support table such that each lever faces in opposite directions relative to the direction in which the first mold part and the second mold part are joined, a first stopper mounted on one side of the rotary table and capable of contacting the lever of the first limit switch, and a second stopper mounted on the other side of the rotary table and capable of contacting the lever of the second limit switch, and the rotation limiting means comprises a locking cylinder including a rod that moves to be inserted from the support table into the rotary table to limit the rotation of the rotary table when the rotary table rotates such that the first stopper contacts the first limit switch or the second stopper contacts the second limit switch.

[0016] The support table comprises a support plate through which the power transmission shaft rotatably penetrates as a center, and a ring-shaped support ring mounted on one surface of the support plate facing the rotary table so as to be concentric with the power transmission shaft; the rotary table comprises a rotary plate to which the power transmission shaft is coupled at the center, and a ring-shaped rotary ring mounted on the other surface of the rotary plate facing the support plate so as to be rotatably supported by the support ring while being concentric with the power transmission shaft; and the rotation limiting means comprises first and second rotation limiting blocks that are mounted so as to protrude toward the support table direction, symmetrically to the left and right with respect to the first diameter line of the power transmission shaft and parallel to each other, and each side facing a direction parallel to the first diameter line is respectively positioned on a second diameter line orthogonal to the first diameter line, and a seating groove is formed in each side that is recessed in the direction of the other side and is extended in the direction in which the first mold part and the second mold part are joined; It is preferable to further provide a rotation limiting bar that is mounted on one surface of the support plate so as to protrude in the direction of the rotating plate, such that the seating groove of the first rotation limiting block and the seating groove of the second rotation limiting block are positioned on a circumferential track line formed with the power transmission shaft in between, and whose side enters and contacts the seating groove of the first rotation limiting block or the seating groove of the second rotation limiting block as the rotating table rotates.

[0017] It is preferable that the rotation limiting means further comprises a plurality of shock-absorbing members, each mounted on the first or second rotation limiting block so as to penetrate into the seating groove on the other side of the first or second rotation limiting block, and which cushion the impact when the first or second rotation limiting block contacts the rotation limiting bar and whose cushioning force can be adjusted.

[0018] The power transmission shaft comprises: a first shaft portion having one end coupled to the center of the other face of the rotating plate and the other end rotatably penetrating the center of the support plate, with a polygonal first spline shaft portion provided on the other end; a second shaft portion having the other end connected to the drive shaft of the driving motor and a second spline shaft portion having a polygonal shape different from the first spline shaft portion provided on one end; and a shaft portion connecting pipe having a power transmission hole formed therein, with the first spline shaft portion inserted and coupled to one side and the second spline shaft portion inserted so as to be movable in the longitudinal direction through the other side, wherein the power transmission hole is formed therein in a first penetrating portion corresponding to the shape of the first spline shaft portion; It is preferable to have a second through-hole formed to correspond to the shape of the second spline shaft portion, which is longer than the second spline shaft portion and communicates with the first through-hole portion so as to block the transmission of shock generated when the first mold portion and the second mold portion are joined, such that the second spline shaft portion is spaced apart from the first spline shaft portion. Effects of the invention

[0019] The rotating device for the double injection mold of the present invention rotates the entire second mold part, which is mated and separated from the first mold part, to form the first and second cavities, so that the structure is simple and various double injection molds can be applied, thus having the advantage of high compatibility efficiency.

[0020] In addition, the rotating device for the double injection mold of the present invention has the advantage of high operational efficiency, as it is provided with a rotation limiting means that restricts rotation when the rotating table is rotated by a set angle.

[0021] In addition, the rotary device for the double injection mold of the present invention has a first shaft portion of a power transmission shaft coupled to a rotary table and a second shaft portion connected to a rotary drive motor, which rotate in the same direction but are spaced apart by a predetermined distance within the shaft portion connecting pipe, thereby preventing the transmission of impact generated during the mating or separation of the first mold portion and the second mold portion to the drive shaft of the rotary drive motor, thus providing the advantage of high durability of the drive portion. Brief explanation of the drawing

[0022] FIG. 1 is a front view of a state in which a first mold part is joined to a second mold part mounted on a rotating device for a double injection mold according to an embodiment of the present invention for primary injection molding, and FIG. 2 is a front view illustrating the state in which the second mold part is rotated by the rotating device of the present invention of FIG. 1 after the first mold part and the second mold part have been separated for secondary injection molding. FIG. 3 is an exploded perspective view of the rotating device of FIG. 1 viewed from one direction, and FIG. 4 is an exploded perspective view of the rotating device of FIG. 1 viewed from another direction, and FIG. 5 is an exploded perspective view of the power transmission shaft of the rotary device of FIG. 1, and FIG. 6 is a partial cross-sectional view of the first or second rotation limiting block side of the rotating device of FIG. 1, and FIG. 7 is a partial side cross-sectional view of the sensing unit and the locking cylinder side of the rotating device of FIG. 1, and FIG. 8 is a block diagram of a rotary device for a double injection mold according to another embodiment of the present invention, and FIG. 9 is a partial plan view of the first or second rotation limiting block side of a rotation device for a double injection mold according to another embodiment of the present invention. Specific details for implementing the invention

[0023] Hereinafter, a rotating device for a double injection mold according to a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0024] FIGS. 1 to 7 illustrate a rotating device (10) for a double injection mold according to one embodiment of the present invention.

[0025] A rotating device (10) for a double injection mold according to one embodiment of the present invention rotates a second mold part (5) that is formed and separated from the first mold part (3) with respect to the first mold part (3) of the double injection mold (2).

[0026] A rotating device (10) for a double injection mold according to one embodiment of the present invention comprises: a rotating table (11) having a second mold part (5) mounted on one side that forms a first cavity (7) for molding a first injection product and a second cavity (8) for molding a second injection product (not shown) on the first injection product (1) by being coupled with a first mold part (3); a support table (31) that supports the rotation of the rotating table (11); a power transmission shaft (51) that rotatably penetrates the center of the support table (31) and is coupled to the center of the rotating table (11); a rotary drive motor (71) for rotating the power transmission shaft (51); and a sensing unit (75) that detects the rotation angle of the rotating table (1) and the power transmission shaft (51). After the first injection molding product is formed, the second mold part is separated from the first mold part, and when the rotary table is rotated by a set angle, a rotation limiting means is provided to limit the rotation of the rotary table.

[0027] The first mold part (3) and the second mold part (5) may have a first cavity (7) for molding a first injection molded product and a second cavity (8) for molding a second injection molded product formed in the first injection molded product, and are not limited to the structure presented.

[0028] The support table (31) and the rotary drive motor (71) are fixedly mounted on one side of an injection molding device (not shown) including a double injection mold (2), and although the rotary drive motor (71) is not specifically shown, the drive shaft may be directly connected to the power transmission shaft (51) or connected via gears.

[0029] The support table (31) is provided with a support plate (32) through which a power transmission shaft (51) can rotate through the center, and a ring-shaped support ring (34) mounted on one side of the support plate (32) facing the rotating table (11) so as to be concentric with the power transmission shaft (51) and having a diameter larger than that of the power transmission shaft (51).

[0030] The rotary table (11) has a rotating plate (12) to which a power transmission shaft (51) is coupled at the center, and a ring-shaped rotating ring (15) mounted on the other side of the rotating plate (12) facing the support plate (32) so as to be concentric with the power transmission shaft (51), has a diameter smaller than that of the support ring (34), and is rotatably connected to the support ring (34).

[0031] The power transmission shaft (51) is provided with a first shaft part (52) having one end bolted to the center of the other side of the rotating plate and the other end rotatably penetrating the center of the support plate (32) and having a polygonal first spline shaft part (55) provided on the other end; a second shaft part (56) having the other end connected to the drive shaft of the drive motor and having a polygonal second spline shaft part different from the first spline shaft part provided on one end; and a shaft part connecting pipe (60) having a power transmission hole formed therein, in which the first spline shaft part is inserted and coupled to one side and the second spline shaft part is inserted so as to be movable in the longitudinal direction on the other side.

[0032] The first shaft portion (52) further comprises a first cylindrical portion (53) in which one side is inserted into a coupling groove formed at the center of the other side of the rotating plate (12) and bolted to the rotating plate (12), and the other side is rotatably supported at the center of the support plate (32), and a second cylindrical portion (54) that extends in a direction away from the rotating plate (12) with a diameter smaller than that of the first cylindrical portion (53), rotatably penetrates the center of the support plate (32), and is connected to the first spline shaft portion (55).

[0033] The other end of the first cylinder (53) is rotatably supported by a guide ring (66) which is mounted in a manner embedded on one side of the support plate (32) so as to be positioned around the second cylinder (54).

[0034] The guide ring (66) may be rotatably mounted on the support plate (32). Alternatively, the guide ring (66) may have a bearing structure having an outer ring fixed to the support plate (32), an inner ring rotatably connected to the outer ring and coupled with a second cylindrical part (54) on the inner side of the outer ring, and a plurality of balls arranged in a circular direction between the outer ring and the inner ring.

[0035] The second shaft portion (57) further comprises a cylindrical motor coupling portion (57) in which one end is gear-connected to or directly shaft-coupled to the drive shaft of the rotary drive motor (71) and the other end is connected to the second spline shaft portion (58).

[0036] The shaft connecting tube (60) passes through a connecting ring (68) whose outer side is connected to the support plate (32), and although not specifically illustrated, it is preferable that the connecting ring (68) be rotatably connected to a bearing.

[0037] The power transmission hole (61) of the shaft section connecting pipe (60) is provided with a first through-hole (62) formed to correspond to the shape of the first spline shaft section (55); and a second through-hole (64) formed to correspond to the shape of the second spline shaft section (58), which is longer than the second spline shaft section (58) and communicates with the first through-hole (62) so that the second spline shaft section (58) is spaced apart from the first spline shaft section (58) so that the shock generated when the first mold section (3) and the second mold section (5) are joined is not transmitted.

[0038] That is, the first spline shaft section (55) and the second spline shaft section (58) are spaced apart by a predetermined distance within the shaft section connecting pipe (60).

[0039] The detection unit comprises a first and second limit switch (76, 79) mounted spaced apart from each other in the rotational direction of the rotary table (11) on a cylinder block (73) mounted to protrude from the edge side of the support plate (32) toward the rotary plate (12), a first stopper (82) mounted to protrude from one side of the rotary plate (12) and capable of contacting the first limit switch (76), and a second stopper (84) mounted to protrude from the other side of the rotary plate (12) and capable of contacting the second limit switch (79).

[0040] The first limit switch (76) and the second limit switch (79) are mounted on a cylinder block (73) that is mounted so as to protrude in the direction of the rotating plate (12) from the edge side of the support plate (32).

[0041] Specifically, the first limit switch (76) and the second limit switch (79) are each mounted symmetrically on both sides of the width of one side of the cylinder block (73) facing the radial direction with respect to the power transmission shaft (51), with each lever (77) (80) facing in opposite directions relative to the direction in which the first mold part (3) and the second mold part (5) are joined.

[0042] Meanwhile, the rotation limiting means comprises a locking cylinder (91) mounted within a cylinder block (73); first and second rotation limiting blocks (101) (121) mounted on a rotating plate (12); a rotation limiting bar (131) mounted on a support plate (32) and in contact with the first or second rotation limiting block (101) (121) to limit the rotation of the rotating table (11); and an impact cushioning member (111) mounted on each of the first and second rotation limiting blocks (101) (121) to cushion the impact when the rotation limiting bar (131) contacts the first or second rotation limiting block (101) (121).

[0043] The locking cylinder (91) comprises a locking cylinder body (92) mounted within a cylinder block (73); and a locking rod (94) that is received in the locking cylinder body (92) so as to be able to move back and forth in the direction of the rotating plate and is able to enter through a first or second rod entry hole (13)(14) that is vertically penetrated at an angle of 180 degrees in the circumferential direction on the edge side of the rotating plate.

[0044] In addition, the rotating device (10) for a double injection mold according to one embodiment of the present invention further comprises a control unit (96) that controls the driving of a locking cylinder (91) so that when the rotating table (11) is rotated such that the first stopper (82) contacts the lever (77) of the first limit switch (76) or the second stopper (84) contacts the lever (80) of the second limit switch (79), the locking rod (94) enters the first or second rod entry hole (13)(14) to restrict the rotation of the rotating table (11).

[0045] The locking cylinder (91) may be a hydraulic cylinder that extends and retracts by normal fluid flow or a linear actuator that extends and retracts by driving an electric motor.

[0046] The first and second rotation limiting blocks (101, 121) have the same structure and are mounted so as to protrude in the direction of the support table (31) on the lower surface of the rotating plate (12) in a manner that is symmetrical to each other with respect to the first diameter line (a) of the power transmission shaft (51), and each side facing in a direction parallel to the first diameter line (a) is mounted so as to be positioned on the second diameter line (b) which is orthogonal to the first diameter line (a).

[0047] The first and second rotation limiting blocks (101, 121) are each equipped with a first block portion (112) having a side face facing a direction parallel to the first diameter line (a) and a second block portion (108) mounted on the side of the first block portion (102) protruding toward the support plate (32) to restrain the shock cushioning member (111) described later.

[0048] The first block part (102) is inserted into the other side of the above-mentioned side and has a seating groove (106) formed that is extended in length in the direction in which the first mold part (3) and the second mold part (5) are joined.

[0049] The first block portion (102) has a rectangular plate coupling portion (103) having a constant width that is inserted and mounted on the plate (12), and a blocking portion (104) connected to the plate coupling portion (103) and protruding in the direction of the support plate (32).

[0050] One side of the blocking part (104) forms a seating groove (106) together with one side of the rotating plate coupling part (103) at the center side, and the other side of the blocking part (104) is formed to protrude more than the other side of the rotating plate coupling part (103). A mounting hole (105) is formed in the blocking part (104) that penetrates perpendicular to the longitudinal direction of the seating groove (106) and parallel to the rotating plate (12) to communicate with the seating groove (106).

[0051] And, in the blocking part (104), a pair of hydraulic line connection holes (107) are formed so as to be in communication with the mounting hole (105) in a direction perpendicular to the penetration direction of the mounting hole (105) and positioned facing each other.

[0052] The second block portion (108) restrains the shock-absorbing member (111) which is bolted to the other side of the blocking portion (104) and mounted in the mounting hole (105).

[0053] The second block portion (108) has a mounting groove (109) formed therein into which one side of the shock-absorbing member (111) protruding from the mounting hole (105) is inserted.

[0054] The rotation limiting bar (131) is mounted on one side of the support plate (32) so as to protrude in the direction of the rotation plate (12), such that the seating groove (106) of the first rotation limiting block (101) and the seating groove (106) of the second rotation limiting block (121) are positioned on a circular track line formed between the power transmission shaft (51).

[0055] The side of the rotation limiting bar (131) enters and contacts the seating groove (106) of the first rotation limiting block (101) or the seating groove (106) of the second rotation limiting block (121) as the rotation of the rotation table (11) occurs.

[0056] A plurality of shock-absorbing members (111) are each mounted on the first or second rotation limiting block (101, 121) so as to penetrate into the seating groove (106) on the other side of the first or second rotation limiting block (101, 121), and have a structure that absorbs shock when the first or second rotation limiting block (101, 121) contacts the rotation limiting bar (131), and has a structure in which the absorbing force can be adjusted.

[0057] The shock absorber member (111) has a general shock absorber structure that can adjust the damping force by hydraulic pressure.

[0058] The shock absorbing member (111) is mounted through the first or second rotation limiting block (101, 121) and comprises a housing (112) having an internal space (not shown) open toward the seating groove (106), a buffer rod (114) with one end inserted into the internal space and having a stroke distance adjusted toward the seating groove (106) depending on the amount of fluid flowing into the housing, a bar contact head (116) coupled to the other end of the buffer rod (114) and having an outer diameter larger than that of the buffer rod (114), and a buffer spring (118) through which the buffer rod (114) passes, with one end supported on the end side of the housing (112) facing the seating groove (106) and the other end supported on the bar contact head (116).

[0059] In addition, the rotating device (10) for a double injection mold according to one embodiment of the present invention is provided with an operating part for driving a rotary drive motor (71) and operating the rotation direction of the drive shaft.

[0060] Now, the operation of a rotating device (10) for a double injection mold according to one embodiment of the present invention having the structure as described above will be explained.

[0061] After the second mold part (5) and the first mold part (3) mounted on the rotary table (11) are joined and the first injection product (1) is formed in the first cavity (7) formed by the first molding groove (4a) and one core (6), the first mold part (3) is separated from the second mold part (5).

[0062] In order to form a second cavity (8), the second mold part (5) is rotated half a turn by a rotating device (10) for a double injection mold according to an embodiment of the present invention so that one core (6) of the second mold part can be fitted together with the second molding groove (4b) of the first mold part (3).

[0063] First, in order for the rotary table (11) to be in a rotatable state, the locking rod (94) of the locking cylinder (91) is moved from the first locking rod entry hole (13) toward the support plate (32) by the operation of the above-mentioned control unit. Then, the rotary drive motor (71) is driven by the operation of the above-mentioned control unit, and the rotary table (11) is rotated.

[0064] The rotation table (11) is restricted from rotating more than half a turn as the second rotation limiting block (121) comes into contact with the rotation limiting bar (131).

[0065] Additionally, when the rotary table (11) is rotated half a turn and the second stopper (84) comes into contact with the lever (80) of the second limit switch (79) and a signal is transmitted to the control unit (96), the control unit (96) drives the locking cylinder (91) so that the locking rod (94) of the locking cylinder (91) enters the second locking rod entry hole (14).

[0066] When the rotary table (11) is rotated half a turn and one core (6) of the second mold part faces the second molding groove (4b) of the first mold part (3), the first and second mold parts are joined together, and then the second injection molded product is injection molded onto the first injection molded product (1) through the second cavity (8).

[0067] Then, when the first mold part (3) is separated from the second mold part (5) after the second injection molding is completed on the first injection molded product (1), the locking rod (94) of the locking cylinder (91) is moved from the second locking rod entry hole (14) toward the support plate (32) by the operation of the control unit so that the rotary table (11) can be rotated again. Then, the rotary drive motor (71) is driven by the operation of the control unit so that the rotary table (11) rotates in the opposite direction.

[0068] When the rotary table (11) is rotated half a turn in the opposite direction and the first stopper (82) comes into contact with the lever (77) of the first limit switch (76) and a signal is transmitted to the control unit (96), the control unit (96) drives the locking cylinder (91) so that the locking rod (94) of the locking cylinder (91) enters the first locking rod entry hole (13).

[0069] The rotating device (10) for a double injection mold according to one embodiment of the present invention, as described so far, rotates the entire second mold part (5) that is coupled with the first mold part (3) to form the first and second cavities (7, 8), so that the structure for rotation is simple and various double injection molds can be applied, thus having the advantage of high compatibility efficiency.

[0070] In addition, the rotating device (10) for a double injection mold according to one embodiment of the present invention has the advantage of high operation efficiency, as it is provided with a rotation limiting means that limits rotation when the rotating table (11) is rotated by a set angle.

[0071] In addition, the rotating device (10) for a double injection mold according to one embodiment of the present invention has a first shaft portion (52) of a power transmission shaft (51) coupled to a rotating table (11) and a second shaft portion (56) connected to a rotary drive motor (71) rotate in the same direction but are spaced apart by a predetermined distance within the shaft portion connecting pipe (60), so that the impact generated when the first mold portion and the second mold portion are joined or separated is prevented from being transmitted to the drive shaft of the rotary drive motor, thus having the advantage of high durability of the drive portion.

[0072] In addition, when a single injection mold, rather than a double injection mold, is mounted on the rotating table (11) according to one embodiment of the present invention, the rotating device (10) may further be provided with a locking bar (99) that fixes the rotating table (11) to the support table (131), with one side detachably bolted to the rotating plate (12) and the other side detachably bolted to the support plate (32).

[0073] Meanwhile, FIG. 8 illustrates a rotating device (210) for a double injection mold according to another embodiment of the present invention. Components having the same function as those in the previously illustrated drawings are indicated by the same reference numerals.

[0074] A rotating device (210) for a double injection mold according to another embodiment of the present invention is formed in the form of an electromagnet in which magnetic force is formed to attach to the rotation limiting bar (131) made of metal when the bar contact head (116) is energized by the control of the control unit (96); and has the same structure as one embodiment of the present invention except that it further comprises a proximity sensor (131), a first fluid supply line (135) opened and closed by a first opening and closing valve (136), and a second fluid supply line (137) opened and closed by a second opening and closing valve (138).

[0075] The proximity sensor (132) is mounted on both sides of the rotation limiting bar (131) facing the first or second rotation limiting block (101, 121) according to the rotation of the rotary table (11). The proximity sensor (132) may be an ultrasonic sensor or a general load cell that detects the load transmitted upon contact with the first or second rotation limiting block (101, 121).

[0076] The first fluid supply line (135) supplies fluid to the housing (112) of the shock-absorbing member, into the space between one end of the flange (not shown) of the buffer rod (114) and one end of the internal space of the housing (112), and the second fluid supply line (135, 138) discharges the fluid within the space between the flange and one end of the internal space to the outside of the housing (112).

[0077] Alternatively, the first fluid supply line (135) may be applied to supply or discharge fluid into the space between one end of the internal space of the housing (112) and a flange (not shown) mounted on one end of the buffer rod (114) of the shock-absorbing member, and the second fluid supply line (135, 138) may be applied to supply or discharge fluid into the space between the flange and the other end of the internal space. In this case, it is preferable that the fluid be filled in an amount less than the amount corresponding to the space between the one end of the internal space of the housing (112) and the space between the flange and the other end of the internal space, so that the buffer rod (114) can move back and forth a predetermined distance relative to the housing (112).

[0078] The first shut-off valve (136) and the second shut-off valve (138) are electronic valves driven and controlled by the control unit (96).

[0079] The control unit (96) is connected to an encoder (not shown) and a proximity sensor (132) mounted on the rotary drive motor (71), and is connected to a first shut-off valve (136) and a second shut-off valve (138).

[0080] When the control unit (96) detects from the proximity sensor (132) that the first or second rotation limiting block (101, 121) is adjacent to the rotation limiting bar (131), it applies electricity to the bar contact head (116) so that a magnetic force is formed on the bar contact head (116). Then, the control unit (96) controls the fluid in the housing by controlling the driving of the first or second opening / closing valve so that the cushioning force of the shock cushioning member (111) is adjusted in response to the rotation speed of the rotary table (11) transmitted from the rotation drive motor (71).

[0081] In a rotating device (210) for a double injection mold according to another embodiment of the present invention, the bar contact head (116) is attached to the rotation limiting bar (131) by magnetic force, and the shock cushioning member (111) cushions the shock, thereby reducing the repulsive force upon contact and improving the shock cushioning efficiency.

[0082] In addition, the rotating device (210) for a double injection mold according to another embodiment of the present invention can automatically adjust the damping force of the shock absorbing member (111) in response to the rotational speed of the rotating table (11), thereby improving the shock absorbing efficiency.

[0083] Meanwhile, FIG. 9 illustrates a rotating device for a double injection mold according to another embodiment of the present invention. Components having the same function as those in the previously illustrated drawings are indicated by the same reference numerals.

[0084] A rotating device for a double injection mold according to another embodiment of the present invention is formed such that, in the structure of one embodiment or another embodiment of the present invention, one surface facing the rotation limiting bar (131) of the bar contact head (116) corresponds to the curvature of the rotation limiting bar (131), and a plurality of ring-shaped cushioning guide grooves (317, 319) having different diameters are further formed along the circumferential direction around the center.

[0085] In addition, a rotating device for a double injection mold according to another embodiment of the present invention further comprises an impact cushioning pad (320) formed of a retractable material that covers one side of a bar contact head (116), a plurality of impact guide rings (351, 353) formed in a ring shape to be inserted into the impact cushioning pad (320) at positions staggered with the cushioning guide grooves (317, 319) and formed to have a width that expands in the direction of the bar contact head (116) and having different diameters, and a gel-type impact cushioning gel (355) that is filled into each cushioning guide groove (317, 319).

[0086] The impact guide ring (351, 353) is formed with a cross-section that is convex in an arc shape in a direction away from the bar contact head (116) and is made of a synthetic resin material having a higher hardness than the impact cushioning pad (320). Additionally, the cushioning guide groove (317, 319) is formed so that its width expands as it moves in the direction of insertion.

[0087] The impact generated when contacting the rotation limiting bar (131) is absorbed by being primarily cushioned by the expandable shock cushioning pad (320), and the impact transmitted to the shock guide ring (351, 353) is guided along the curved surface of the shock guide ring (351, 353) toward the cushioning guide groove (317, 319).

[0088] And, the impact induced toward the cushioning guide groove (317, 319) is transmitted to and absorbed by the shock cushioning gel (355) filled within the cushioning guide groove (317, 319).

[0089] In a rotating device for a double injection mold according to another embodiment of the present invention, the shock transmitted to the shock-absorbing pad (320) covering the bar contact head (116) is dispersed or absorbed as it moves toward the shock-absorbing gel (355) of the cushioning guide groove (317, 319) through the shock guide ring (351, 353), so that the shock-absorbing efficiency can be further improved when the first rotation limiting block (101) or the second rotation limiting block (121) contacts the rotation limiting bar (131).

[0090] Although the rotating device for a double injection mold according to the present invention has been described above with reference to an example illustrated in the drawings, this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true scope of technical protection of the present invention should be determined by the technical concept of the appended claims. Explanation of the symbols

[0091] 2 : Double injection mold 10 : Rotating device for double injection mold 11 : Rotary table 31 : Support table 51: Power transmission shaft 52: First shaft section 56: Second shaft section 60: Shaft connector 75 : Detection unit 76 : First limit switch 79 : 2nd limit switch 82 : 1st stopper 84 : Second stopper 91 : Locking cylinder 101 : First rotation limiting block 111 : Shock cushioning member 121 : Second rotation limit block

Claims

Claim 1 A rotary device for a double injection mold, characterized by comprising: a rotary table having a second mold part mounted on one side that is coupled with a first mold part to form a first cavity for molding a first injection product and a second cavity for molding a second injection product on the first injection product; a support table that supports the rotation of the rotary table; a power transmission shaft that rotatably penetrates the center of the support table and is coupled to the center of the rotary table; a rotary drive motor for rotating the power transmission shaft; a sensing unit that detects the rotation angle of the rotary table and the power transmission shaft; and a rotation limiting means that limits the rotation of the rotary table when the rotary table is rotated by a set angle while the second mold part is separated from the first mold part after molding the first injection product. Claim 2 A rotating device for a double injection mold according to claim 1, wherein the sensing unit comprises first and second limit switches symmetrically arranged on one side of the support table such that each lever faces in opposite directions with respect to the direction in which the first mold part and the second mold part are joined, a first stopper mounted on one side of the rotary table and capable of contacting the lever of the first limit switch, and a second stopper mounted on the other side of the rotary table and capable of contacting the lever of the second limit switch, and the rotation limiting means comprises a locking cylinder including a rod that moves to be inserted from the support table into the rotary table to limit the rotation of the rotary table when the rotary table rotates such that the first stopper contacts the first limit switch or the second stopper contacts the second limit switch. Claim 3 In claim 1, the support table comprises a support plate through which the power transmission shaft rotatably penetrates as a center, and a ring-shaped support ring mounted concentrically with the power transmission shaft on one surface of the support plate facing the rotary table; the rotary table comprises a rotary plate to which the power transmission shaft is coupled at the center, and a ring-shaped rotary ring rotatably supported by the support ring on the other surface of the rotary plate facing the support plate, concentrically with the power transmission shaft; the rotation limiting means comprises first and second rotation limiting blocks that are mounted so as to protrude in the direction of the support table, symmetrically to the left and right with respect to the first diameter line of the power transmission shaft and parallel to each other, and each side facing a direction parallel to the first diameter line is respectively positioned on a second diameter line orthogonal to the first diameter line, and a seating groove is formed in each side that is recessed in the direction of the other side and is extended in the direction in which the first mold part and the second mold part are joined; and A rotating device for a double injection mold, further comprising: a rotation limiting bar mounted on one surface of the support plate so as to protrude in the direction of the rotating plate, such that the seating groove of the first rotation limiting block and the seating groove of the second rotation limiting block are positioned on a circumferential track line formed with the power transmission shaft in between, and the side thereof enters and contacts the seating groove of the first rotation limiting block or the seating groove of the second rotation limiting block as the rotating table rotates. Claim 4 A rotating device for a double injection mold according to claim 3, wherein the rotation limiting means is respectively mounted on the first or second rotation limiting block so as to penetrate into the seating groove on the other side of the first or second rotation limiting block, and further comprises a plurality of shock-absorbing members that cushion the shock when the first or second rotation limiting block contacts the rotation limiting bar and whose cushioning force can be adjusted. Claim 5 In claim 1, the power transmission shaft comprises a first shaft portion having one end coupled to the center of the other face of the rotating plate and the other end rotatably penetrating the center of the support plate, with a polygonal first spline shaft portion provided on the other end; a second shaft portion having the other end connected to the drive shaft of the drive motor and having a second spline shaft portion having a polygonal shape different from the first spline shaft portion provided on one end; and a shaft portion connecting pipe having a power transmission hole formed therein, through which the first spline shaft portion is inserted and coupled to one side and the second spline shaft portion is inserted so as to be movable in the longitudinal direction to the other side, wherein the power transmission hole comprises a first penetration portion formed through to correspond to the shape of the first spline shaft portion; and a second spline shaft portion formed through to correspond to the shape of the second spline shaft portion, wherein the second spline shaft portion is spaced apart from the first spline shaft portion to transmit shock generated when the first mold portion and the second mold portion are joined. A rotary device for a double injection mold, characterized by having a second penetration portion that penetrates longer than the second spline shaft portion to be blocked and communicates with the first penetration portion. Claim 6 In claim 4, the shock absorbing member comprises a housing having an internal space that is open toward the seating groove and is mounted through the first or second rotation limiting block; a buffer rod with one end inserted into the internal space, the stroke distance of which is adjusted toward or toward the seating groove according to the amount of fluid flowing into the housing; a bar contact head coupled to the other end of the buffer rod and having an outer diameter larger than that of the buffer rod; and a buffer spring having the buffer rod penetrated through it, with one end supported by the end of the housing facing the seating groove and the other end supported by the bar contact head, wherein the bar contact head is formed in the shape of an electromagnet that forms a magnetic force to attach to the rotation limiting bar made of metal when energized. Claim 7 A rotary device for a double injection mold according to claim 4, further comprising: a proximity sensor mounted on both sides of the rotation limiting bar facing the first or second rotation limiting block according to the rotation of the rotary table; and a control unit connected to the drive motor and the proximity sensor, and connected to a first opening / closing valve that opens / closes a first fluid supply line that supplies fluid connected to the housing of the shock absorbing member and a second opening / closing valve that opens / closes a second fluid supply line that discharges fluid connected to the housing, wherein when the proximity sensor detects that the first or second rotation limiting block is adjacent to the rotation limiting bar, the control unit adjusts the first or second opening / closing valve so as to adjust the cushioning force of the shock absorbing member in response to the rotation speed of the rotary table. Claim 8 In claim 6, the bar contact head is formed such that one surface contacting the rotation limiting bar corresponds to the curvature of the rotation limiting bar, and a plurality of ring-shaped cushioning guide grooves having different diameters are formed along the circumferential direction around the center, and the shock cushioning member further comprises a shock cushioning pad formed of a stretchable material covering one surface of the bar contact head, a plurality of shock guide rings having different diameters formed in a ring shape to be inserted into the shock cushioning pad at a position staggered with the cushioning guide grooves and formed to have a width that expands in the direction of the bar contact head, and a gel-type shock cushioning gel filled in each of the cushioning guide grooves.

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