Die post and automatic die replacement system

Abstract

A die post according to one embodiment comprises a die unit that deforms the rivet by receiving a pressure, a through hole formed along a first central axis, a first end and a second end formed to face each other along the first central axis, a housing in which the die unit is disposed at the first end, a first push rod extending along the first central axis, a first pusher that is pressed by an external force applied along the first central axis on the opposite side of the die unit, a second push rod having a pusher recess and a die recess, and a second pusher that is pressed by the first pusher being inserted into the pusher recess. The first pusher may be movable between a fully locked position in which movement of the second pusher and the die unit in the direction of the first central axis is restricted within the housing, a partially locked position in which movement of the second pusher in the direction of the first central axis is possible and movement of the die unit in the direction of the first central axis is restricted, and an unlocked position in which movement of the second pusher and the die unit in the direction of the first central axis is possible.

Description

Technology Field

[0001] The present disclosure relates to a die post and an automatic die replacement system. Background Technology

[0002] To lighten automobiles, sheet metal made of lightweight materials such as aluminum alloys, magnesium alloys, or composite materials is used for car bodies. Spot welding is generally used for assembling car bodies or joining sheet metal. Spot welding exerts thermal effects on the objects to be joined. Recently, as an alternative to spot welding, a riveting process is being used to join the aforementioned lightweight sheet metal by riveting using rivets, for example, self-piercing rivets.

[0003] Riveting using self-piercing rivets eliminates the need to form rivet holes in the objects to be joined in advance. For example, with the lowest plate among a plurality of plates to be joined placed on a die unit, a self-piercing rivet can be punched into the uppermost plate by a self-piercing riveting device. As the self-piercing rivet is punched, the shank of the self-piercing rivet penetrates the uppermost plate, and plastically deforms inside the lowermost plate by the die before the shank completely penetrates the lowermost plate. Accordingly, an interlock is formed at the joint of the plurality of plates by the self-piercing rivet, allowing the plurality of plates to be firmly joined. Plates joined by riveting using self-piercing rivets can be joined with a strong bonding force without being affected by thermal influence.

[0004] A conventional riveting device using self-piercing rivets may have a punch device for punching the self-piercing rivets, a die post for supporting the sheet metal, and a frame on which the punch device and the die are mounted. In addition, under the premise that the same rivet is used, the riveting device can form a good joint only if punching is performed on an optimal die unit as the material and thickness of multiple sheet metals change. Accordingly, in the case where the die unit needs to be replaced due to changes in the material and thickness of the sheet metals to be riveted, the operator has no choice but to replace the die unit manually, which has resulted in reduced working time and efficiency. Prior art literature

[0005] Korean Registered Patent Publication No. 10-1819902 Korean Registered Patent Publication No. 10-2063043 The problem to be solved

[0006] The present disclosure provides technology regarding a die post and an automatic die replacement system. means of solving the problem

[0007] One aspect of the present disclosure provides embodiments of a die post of a riveting device for joining at least a first plate and a second plate by riveting. A die post according to one embodiment comprises: a die unit that deforms the rivet by receiving a pressing force; a through hole formed along a first central axis and including a first offset and a second offset; a housing having a first end and a second end formed to face each other along the first central axis, wherein the die unit is disposed at the first end; a first pusher that is pressed by an external force applied along the first central axis on the opposite side of the die unit; a second pusher having a pusher recess and a die recess; and a second pusher that is pressed by the first pusher being inserted into the pusher recess. The first pusher has a fully locked position in which movement in the direction of the first central axis of the second pusher and the die unit is restricted within the housing; a partially locked position in which movement in the direction of the first central axis of the second pusher is possible and movement in the direction of the first central axis of the die unit is restricted; and movement in the direction of the first central axis of the second pusher and the die unit It is possible to move between possible unlock locations.

[0008] In one embodiment, the second pusher further comprises a second push rod including an upper ball receiving portion and a lower ball receiving portion, a first ball received in the upper ball receiving portion and a second ball received in the lower ball receiving portion, the die unit includes a die groove, and the first pusher further comprises a pusher groove, and in the fully locked position, the first ball is seated in the die groove and contacts the inner wall of the through hole, and the second ball is discharged from the pusher groove and can contact the second offset.

[0009] In one embodiment, at the partial locking position, the second ball is seated in the pusher groove and comes into contact with the inner wall of the through hole positioned above the second offset, thereby unlocking the second pusher.

[0010] In one embodiment, at the unlock position, the first ball is discharged from the die groove and comes into contact with the first offset, thereby unlocking the die unit.

[0011] In one embodiment, the through hole further includes a third offset and further includes a first spring disposed between the second pusher and the housing to apply a pushing force against each other and a second spring disposed between the first pusher and the second pusher to apply a pushing force against each other, and when the external force is released, the first pusher can return to the fully locked position by means of the first spring and the second spring.

[0012] One aspect of the present disclosure provides embodiments of an automatic die replacement system for a riveting device. An automatic die replacement system according to one embodiment comprises a riveting device for joining at least a first plate and a second plate by riveting, and a die replacement device for replacing a die unit of the riveting device, wherein the riveting device comprises a frame having a first free end and a second free end spaced apart from each other, and a die post according to claim 1 mounted on the second free end, and wherein the die replacement device comprises a die sensing module for detecting whether the die post has entered, a push module for unlocking the die unit by pressing the first pusher of the die post along the first central axis, and a die grip module for replacing the die unit with a new die unit, wherein when the entry of the die post is confirmed by the die sensing module, the die replacement device may unlock the die unit by pressing the first pusher by the push module and replace the die unit by the die grip module.

[0013] In one embodiment, the die sensing module may include an entry confirmation sensor that detects whether the die post has been entered, a die confirmation sensor that detects whether the die unit has been placed in a correct position for replacement, and a mounting confirmation sensor that detects whether the die unit has been separated from a first end of the housing. Effects of the invention

[0014] A die post according to one embodiment of the present disclosure may have a double pusher structure comprising a first pusher and a second pusher. Accordingly, the release of the die unit is achieved only when the die unit is pushed upward by pushing the first pusher from below, and the release of the die unit can be prevented when the die unit is pulled upward.

[0015] In a die post according to one embodiment of the present disclosure, the extent to which the first pusher and the second pusher can be pushed out to the maximum is determined by a spring and a protrusion structure disposed inside the housing, so a separate stopper structure is not required, thereby providing a simple appearance and reducing the possibility of failure.

[0016] An automatic die replacement system according to one embodiment of the present disclosure can improve the throughput of a riveting device by automatically replacing the die unit of the riveting device.

[0017] The effects according to the technology of the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description of the present disclosure. Brief explanation of the drawing

[0018] FIG. 1 schematically illustrates an example in which a riveting device according to one embodiment is used. FIG. 2 schematically illustrates an example in which a plate is joined by a riveting device according to one embodiment. FIG. 3 is a perspective view illustrating a frame of a riveting device and a die post according to one embodiment. FIG. 4 is a front view of a die post according to one embodiment. FIG. 5 is a cross-sectional view of a die post with the die unit removed according to one embodiment. FIG. 6 is an exploded perspective view of a die post according to one embodiment. FIG. 7 is an enlarged view of the upper part of the first pusher in the cross-sectional view of the die post according to FIG. 5. FIG. 8a is a cross-sectional view of a die post according to one embodiment when the first pusher is placed in a fully locked position. Figure 8b is an enlarged view of area A of Figure 8a. Fig. 8c is an enlarged view of area B of Fig. 8a. FIG. 9a is a cross-sectional view of a die post according to one embodiment when the first pusher is placed in a partially locked position. Figure 9b is an enlarged view of area C of Figure 9a. Fig. 9c is an enlarged view of area D of Fig. 9a. FIG. 10a is a cross-sectional view of a die post according to one embodiment when the first pusher is placed in the unlocked position. Figure 10b is an enlarged view of region E of Figure 10a. Fig. 10c is an enlarged view of region F of Fig. 10a. FIG. 11 is a perspective view of a die replacement device according to one embodiment. Figure 12 is an enlarged view of region G of Figure 11. FIG. 13a sequentially illustrates an example in which a die unit is replaced by an automatic die replacement system according to one embodiment. FIG. 13b sequentially illustrates an example in which a die unit is replaced by an automatic die replacement system according to one embodiment, following FIG. 13a. FIG. 13c sequentially illustrates an example in which a die unit is replaced by an automatic die replacement system according to one embodiment, following FIG. 13b. FIG. 13d sequentially illustrates an example in which a die unit is replaced by an automatic die replacement system according to one embodiment, following FIG. 13c. Specific details for implementing the invention

[0019] The embodiments of the present disclosure are illustrative for the purpose of explaining the technical concept of the present disclosure. The scope of rights according to the present disclosure is not limited to the embodiments presented below or the specific description thereof.

[0020] All technical and scientific terms used in this disclosure, unless otherwise defined, have the meaning generally understood by those skilled in the art to which this disclosure pertains. All terms used in this disclosure are selected for the purpose of further clarifying this disclosure and are not selected to limit the scope of the rights under this disclosure.

[0021] Expressions such as 'comprising', 'having', 'having', etc. used in this disclosure should be understood as open-ended terms implying the possibility of including other embodiments, unless otherwise stated in the phrase or sentence containing such expressions.

[0022] Unless otherwise stated, singular expressions described in this disclosure may include a plural meaning, and this applies likewise to singular expressions described in the claims.

[0023] Expressions such as 'first', 'second', etc. used in this disclosure are used to distinguish multiple components from one another and do not limit the order or importance of said components.

[0024] In the present disclosure, where it is stated that a component is 'connected' or 'combined' to another component, it should be understood that the component may be directly connected or combined to the other component, or connected or combined through a new component.

[0025] As used in this disclosure, "upper direction" refers to a direction along a first central axis from the second end of the housing toward the first end, and "lower direction" refers to a direction opposite to the upper direction. Additionally, "upper" or "upper end" as used in this disclosure is based on the upper direction, and "lower" or "lower end" as used in this disclosure is based on the lower direction.

[0026] Hereinafter, embodiments will be described with reference to the attached drawings. In the attached drawings, identical or corresponding components are given the same reference numerals. Furthermore, in the description of the embodiments below, the description of identical or corresponding components may be omitted. However, even if a description of a component is omitted, it is not intended that such component is not included in any embodiment.

[0027] The embodiments disclosed below and the embodiments illustrated in the attached drawings relate to a riveting device for joining at least two plates using rivets. A riveting device according to one embodiment may be used to join at least two plates constituting the body of a vehicle using rivets, but the use of the riveting device is not limited to joining vehicle plates.

[0028] FIG. 1 schematically illustrates an example in which a riveting device is used in an automatic die replacement system (1) of a riveting device (10) according to one embodiment, and FIG. 2 schematically illustrates an example in which plate materials (51, 52, 53) are joined by a riveting device (10) according to one embodiment. The following description will be explained with reference to FIG. 1 and FIG. 2.

[0029] A riveting device (10) according to one embodiment includes a frame (100) which is a basic structure of the riveting device (10). The frame (100) may be detachably mounted to the free end of a robot arm, for example, in a forming process of a car body. Alternatively, a worker may perform a riveting operation manually while the frame (100) is mounted on a stationary structure. A riveting device (10) according to one embodiment includes a riveting gun unit (200) and a die post (300) mounted on the frame (100). The riveting gun unit (200) presses the rivet toward the die post (300). The die post (300) deforms the rivet in response to the pressure applied by the riveting gun unit (200). The frame (100) has two free ends, and the workpiece to be joined by the riveting device is positioned between the two free ends of the frame.

[0030] Referring to FIG. 1, a riveting device (10) according to one embodiment may further include a rivet charging stand unit (500) used to charge rivets into a rivet gun unit (200), and a rivet feeder (600) connected to the rivet charging stand unit (500) and supplying a plurality of rivets to the rivet charging stand unit (500). A controller (not shown) may control operating elements of the riveting device, such as the rivet gun unit (200), the rivet charging stand unit (500), and the rivet feeder (600), as well as various processes in the riveting process. Additionally, a die replacement device (40) may be positioned near the riveting device (10) to replace a die unit (e.g., die unit (310) of FIG. 3) coupled to a die post (e.g., die post (300) of FIG. 3) of the riveting device (10). The die replacement device (40) will be described in more detail below with reference to FIGS. 11 to 13d.

[0031] Referring to FIG. 2, a plurality of joining objects, namely a first plate (51), a second plate (52), and a third plate (53), can be joined by a self-piercing rivet (20) by a riveting device according to one embodiment. The self-piercing rivet (20) has a disc-shaped head (23) and a shank (24) that extends from the head (23) and is formed as a hollow cylinder. Referring to the upper left portion of FIG. 2, with the first plate (51), the second plate (52), and the third plate (53) partially overlapping, a rivet gun unit (200) advances toward the first plate (51) in the forward direction (AD) and contacts the upper surface of the first plate (51), and a die post (300) contacts the lower surface of the third plate (53). The rivet gun unit (200) presses the self-piercing rivet (20) loaded therein against the first plate (51). Referring to the upper right portion of FIG. 2, the overlapping portion of the first plate (51), the second plate (52), and the third plate (53) is deformed and protrudes toward the die post (300) by the pressing force (PF) applied by the rivet gun unit (200) to the self-piercing rivet (20) (specifically, the shank (24) of the self-piercing rivet) by the rivet gun unit (200) and penetrates the first plate (51) and the second plate (52) (piercing process) and penetrates into the interior of the third plate (53) to a predetermined depth. As the shank (24) penetrates into the interior of the third plate (53), the shank (24) is plastically deformed in a shape that expands in diameter by the pressure and the die post (300) (forming process). Accordingly, the first plate (51), the second plate (52), and the third plate (53) can be firmly joined through the plastically deformed self-piercing rivet (head and shank of the self-piercing rivet). Then, as shown in the lower left portion of FIG. 2, the rivet gun unit (200) is retracted in the retraction direction (RD) from the joined first plate (51), second plate (52), and third plate (53).

[0032] The first plate (51), the second plate (52), and the third plate (53) shown in FIG. 2 may be of the same or different types of plates. The first plate (51), the second plate (52), and the third plate (53) may be made of steel, aluminum, magnesium, or fiber-reinforced plastic such as carbon fiber reinforced plastic. FIG. 2 illustrates an example of joining three plates (e.g., the first plate (51), the second plate (52), and the third plate (53)) by means of a rivet gun unit (200), a die post (300), and a self-piercing rivet (20). However, a riveting device according to one embodiment may join two or four or more plates by means of a self-piercing rivet, depending on riveting conditions such as the size of the self-piercing rivet (20) and the pressure of the self-piercing rivet (20).

[0033] FIG. 3 is a perspective view illustrating the frame (100) and die post (300) of a riveting device (10) according to one embodiment.

[0034] A riveting device (10) according to one embodiment includes a frame (100) which is a base structure, a riveting gun unit (e.g., riveting gun unit (200) of FIG. 1) which can be mounted on a first free end (111) of the frame (100), and a die post (300) which is mounted on a second free end (112) of the frame (100).

[0035] The frame (100) has a roughly C-shape so as to be positioned at the joint portion of the first and second plates described above. The shape of the frame (100) is not limited to a C-shape and may have a shape that allows it to be positioned at the joint portion of the first and second plates described above. The frame (100) may be made of high-strength steel. A plurality of openings (113) are formed in the frame (100), so that the frame (100) may have lightness and high strength.

[0036] A C-shaped frame (100) can be formed as a structure having a first free end (111) and a second free end (112) spaced apart from each other. The first free end (111) and the second free end (112) can be spaced apart along the direction of applying pressure to a self-piercing rivet (e.g., the self-piercing rivet (20) of FIG. 2), and the aforementioned first and second plates can be positioned between the first and second free ends (111, 112). As an example, the frame (100) can be mounted on a robot at a mount portion (114) formed in the middle portion between the first and second free ends (111, 112). A rivet gun unit (e.g., the rivet gun unit (200) of FIG. 1 and / or FIG. 2) can be mounted on the first free end (111) of the frame (100). A rivet (e.g., a self-piercing rivet) is loaded inside the rivet gun unit (200), and the rivet gun unit (200) is configured to press the rivet against the first plate and penetrate the first plate.

[0037] The die post (300) may be mounted on the second free end (112) of the frame (100). The die post (300) may include a die unit (310) that plastically deforms a rivet penetrating the first plate. The die post (300) will be described in more detail below with reference to FIGS. 4 to 7.

[0038] FIG. 4 is a front view of a die post (300) according to one embodiment. FIG. 5 is a cross-sectional view of a die post (300) according to one embodiment with the die unit (310) removed. FIG. 6 is an exploded perspective view of a die post (300) according to one embodiment. FIG. 7 is an enlarged view of the upper portion of the first pusher (330) in the cross-sectional view of the die post (300) according to FIG. 5. Referring to FIG. 4 through FIG. 7, a die post (300) according to one embodiment may include a die unit (310), a housing (320), a first pusher (330), a second pusher (340), a snap ring (350), a first spring (360), and a second spring (370).

[0039] The die unit (310) can plastically deform a rivet (e.g., self-piercing rivet (20) of FIG. 2) by receiving pressure on at least two or more plates. The die unit (310) may include a die groove (311). A first ball (344) of a second pusher (340) may be seated in the die groove (311). When the first ball (344) of the second pusher (340) is seated in the die groove (311), the die unit (310) is fixed to a first end (320a) of the housing (320). When the first ball (344) of the second pusher (340) is discharged from the die groove (311), the die unit (310) is released from the first end (320a) of the housing (320). That is, the die unit (310) may be detachably disposed at the first end (320a) of the housing (320). The die unit (310) may include a die column (312) and a die head (313). The die column (312) corresponds to a portion inserted into the interior of the housing (320), and the die head (313) corresponds to a portion attached to the top of the die column (312) that plastically deforms the self-piercing rivet (20) under pressure. A die groove (311) may be formed in the die column (312).

[0040] The housing (320) may include a through hole (321) formed along a first central axis (CA1). A plurality of components of the die post (300) may be accommodated in the through hole (321) of the housing (320). For example, referring to the exploded view of FIG. 6, a die unit (310), a first spring (360), a second pusher (340), a second spring (370), a first pusher (330), and a snap ring (350) may be arranged in order in the through hole (321) of the housing (320). Additionally, the housing (320) may include a first end (320a) and a second end (320b) formed to face each other along the first central axis (CA1). For example, the first end (320a) may correspond to the uppermost part of the housing (320), and the second end (320b) may correspond to the lowermost part of the housing (320). A die unit (310) may be in contact with the first end (320a). Additionally, a plurality of offsets (e.g., the first offset (322), the second offset (323), the third offset (324), and the fourth offset (325) of FIG. 5) formed along the through hole (321) inside the housing (320) may be included.

[0041] The first pusher (330) includes a first push rod (331) extending downward along the first central axis (CA1) beyond the second end (320b) of the housing (320), a pusher groove (332) formed on the upper part of the first push rod (331) where a second ball (345) can be seated, and a first flange (333) extending radially outward from the first push rod (331) (e.g., away from the first central axis (CA1)). The first pusher (330) can be pushed upward by an external force applied upward along the first central axis (CA1) from the opposite side of the die unit (310). As the first pusher (330) is pushed upward, it can press the second pusher (340) upward. The first pusher (330) may be positioned in a fully locked position within the housing (320) where the movement of the second pusher (340) and the die unit (310) is restricted, a partially locked position where only the movement of the second pusher (340) is possible and the movement of the die unit (310) is restricted, and an unlocked position where both the movement of the second pusher (340) and the die unit (310) is possible. Each of the above positions of the first pusher (330) will be described in more detail below with reference to FIGS. 8a to 10c.

[0042] The second pusher (340) includes a second push rod (341) that extends along a first central axis (CA1) and includes an upper ball receiving portion (3411) and a lower ball receiving portion (3412), a pusher recess (342) formed at the lower part of the second push rod (341), a die recess (343) formed at the upper part of the second push rod (341), a first ball (344) received in the upper ball receiving portion (3411), a second ball (345) received in the lower ball receiving portion (3412), and a second flange (346) that extends radially outward from the second push rod (341).

[0043] In one embodiment, referring to FIG. 7, the first ball (344) of the second push rod (341) may be received in the upper ball receiving portion (3411) of the second push rod (341). Specifically, the first ball (344) may be loosely received in the upper ball receiving portion (3411). The first ball (344) may move within the upper ball receiving portion (3411) in a direction across the first central axis (CA1) (in the direction of the arrow in FIG. 7). The diameter of the first ball (344) may be greater than the thickness of the side wall of the second push rod (341) surrounding the die recess (343). Accordingly, referring to FIG. 7, when the first ball (344) moves within the upper ball receiving portion (3411) in a direction toward the first central axis (CA1), a portion of the first ball (344) may protrude toward the die recess (343). Meanwhile, when the first ball (344) moves outwardly within the upper ball receiving portion (3411), a portion of the first ball (344) may protrude outward beyond the outer surface of the second push rod (341).

[0044] Similar to the example of the first ball (344) and the upper ball receiving portion (3411), the second ball (345) of the second push rod (341) may be received in the lower ball receiving portion (3412) of the second push rod (341). Specifically, the second ball (345) may be loosely received in the lower ball receiving portion (3412). The second ball (345) may move in a direction across the first central axis (CA1) within the lower ball receiving portion (3412). The diameter of the second ball (345) may be greater than the thickness of the side wall of the second push rod (341) surrounding the pusher recess (342). For example, when the second ball (345) moves in a direction toward the first central axis (CA1) within the lower ball receiving portion (3412), a portion of the second ball (345) may protrude toward the pusher recess (342). Meanwhile, when the second ball (345) moves outwardly within the lower ball receiving portion (3412), a portion of the second ball (345) may protrude outward beyond the outer surface of the second push rod (341).

[0045] The snap ring (350) can serve as a stopper to prevent the first pusher (330) from being completely discharged downward by gravity when the first pusher (330) moves up and down along the first central axis (CA1). The snap ring (350) can restrict further movement by contacting the lower surface of the first flange (333) when the first pusher (330) reaches a certain position (e.g., the fully locked position in FIGS. 8a to 8c) within the through hole (321) of the housing (320).

[0046] Referring further to FIGS. 4 through 7, the first spring (360) may be positioned between the second pusher (340) and the housing (320). The first spring (360) may apply a pushing force between the second pusher (340) and the housing (320). Specifically, the first spring (360) may be compressed between the second pusher (340) and the third offset (324) of the housing (320) to apply a pushing force. When the second pusher (340) is pressed upward by the first pusher (330) and the external force is removed, the second pusher (340) may return downward by the force of the first spring (360).

[0047] The second spring (370) may be positioned between the first pusher (330) and the second pusher (340). The second spring (370) may apply a pushing force between the first pusher (330) and the second pusher (340). When the first pusher (330) is pressed upward by an external force and then the external force is released, and the second pusher (340) returns downward by the first spring (360), the first pusher (330) may also return downward by the force of the second spring (370).

[0048] Hereinafter, with reference to FIGS. 8a to 10c, the arrangement of the first ball (344) and the second ball (345) of the second pusher (340) when the first pusher (330) is placed in a specific position, and the movement of each component accordingly, will be explained.

[0049] FIGS. 8a to 8c are drawings illustrating the state when the first pusher (330) is placed in a fully locked position. FIG. 8a is a cross-sectional view of a die post (300) according to one embodiment when the first pusher (330) is placed in a fully locked position. FIG. 8b is an enlarged view of area A of FIG. 8a. FIG. 8c is an enlarged view of area B of FIG. 8a.

[0050] Referring to FIG. 8a, the case where the first pusher (330) is in a fully locked position means that the first pusher (330) is positioned at the bottom within the through hole (321) of the housing (320). In the fully locked position, the first flange (333) of the first pusher (330) may come into contact with the snap ring (350). When the first pusher (330) is in a fully locked position, the tensile elastic force applied by the first spring (360) and the second spring (370) to the housing (320), the first pusher (330), and the second pusher (340) may be very small or zero. When the first pusher (330) is in a fully locked position, the movement of the second pusher (340) and the die unit (310) in the direction of the first central axis (CA1) is restricted.

[0051] Referring to FIG. 8b, which is an enlarged view of area A in FIG. 8a, in the fully locked position, the first pusher (330) is positioned at the bottom within the through hole (321). In the fully locked position, the first flange (333) of the first pusher (330) contacts the snap ring (350), and the first flange (333) is positioned to be spaced apart from the second flange (346). In the fully locked position, the second ball (345) received in the lower ball receiving portion (3412) is positioned at a position offset from the pusher groove (332) of the first pusher (330). For example, in the fully locked position, the second ball (345) is positioned above the pusher groove (332). Accordingly, the second ball (345) received in the lower ball receiving portion (3412) of the second push rod (341) comes into contact with the outer surface of the first push rod (331) of the first pusher (330). The outer diameter of the first push rod (331) is equal to the inner diameter of the pusher recess (342) or is extremely small compared to the inner diameter of the pusher recess (342). Accordingly, the second ball (345) is pushed in the opposite direction of the first central axis (CA1) by the outer surface of the first push rod (331) and protrudes toward the housing (320) (in the direction of the arrow shown inside the second ball (345) in FIG. 8B). The second ball (345) protruding toward the housing (320) comes into contact with the second offset (323) of the housing (320), thereby restricting the movement of the second pusher (340) in the up and down direction. Accordingly, the movement of the second pusher (340) in the direction of the first central axis (CA1) is restricted by the engagement of the second ball (345) and the second offset (323) of the housing (320).

[0052] Referring to FIG. 8c, which is an enlarged view of area B of FIG. 8a, in the fully locked position, the die unit (310) contacts the first end (320a) of the housing (320). The outer diameter of the die column (312) matches the inner diameter of the die recess (343) or is extremely small compared to the inner diameter of the die recess (343). In the fully locked position, the first ball (344) of the upper ball receiving portion (3411) is positioned at a location corresponding to the die groove (311). In the fully locked position, the first ball (344) is positioned below the first offset (322) of the housing (320). Accordingly, the first ball (344) is pushed by the inner circumference of the housing (320) in a direction toward the first central axis (CA1) (the direction of the arrow shown inside the first ball (344) in FIG. 8c) and is seated in the die groove (311) of the die unit (310). Additionally, the first ball (344) contacts the inner wall of the through hole (321) of the housing (320). The first ball (344), seated in the die groove (311), can restrict the movement of the die unit (310) in the vertical direction. Accordingly, the movement of the die unit (310) in the direction of the first central axis (CA1) is restricted by the engagement of the first ball (344) and the die groove (311).

[0053] As described above with reference to FIGS. 8a to 8c, when the first pusher (330) is positioned in a fully locked position, the first ball (344) and the second ball (345) protrude in the direction toward the first central axis (CA1) and in the direction opposite to the first central axis (CA1), respectively, thereby restricting the movement of the die unit (310) and the second pusher (340). Accordingly, when the first pusher (330) is positioned in a fully locked position, even if the die unit (310) is pulled from the upper side by an external force, it does not fall out of the housing (320) due to the double locking structure (i.e., locking by the engagement of the first ball (344) and the die groove (311) and locking by the catch of the second ball (345) and the second offset (323).

[0054] FIGS. 9a to 9c are drawings illustrating the state when the first pusher (330) is placed in a partially locked position. FIG. 9a is a cross-sectional view of a die post according to one embodiment when the first pusher is placed in a partially locked position. FIG. 9b is an enlarged view of area C of FIG. 9a. FIG. 9c is an enlarged view of area D of FIG. 9a.

[0055] Referring to FIG. 9a, the case where the first pusher (330) is in a partially locked position means that the first pusher (330) has advanced upward by a certain distance within the through hole (321) of the housing (320). In the partially locked position, the first flange (333) of the first pusher (330) may be separated from the snap ring (350). When the first pusher (330) is in a partially locked position, the tensile elastic force applied by the first spring (360) to the second pusher (340) and the housing (320) may be very small or zero. On the other hand, since the second spring (370) is compressed to the maximum in the partially locked position, the tensile elastic force applied by the second spring (370) to the first pusher (330) and the second pusher (340) may be maximum. With the first pusher (330) in a partially locked position, the second pusher (340) is free to move in the direction of the first central axis (CA1), whereas the die unit (310) is restricted from moving in the direction of the first central axis (CA1).

[0056] Referring to FIG. 9b, which is an enlarged view of region C in FIG. 9a, in a partial locking position, the first pusher (330) is positioned at a height of a certain distance within the through hole (321). In a partial locking position, the first flange (333) of the first pusher (330) is spaced apart from the snap ring (350), and the first flange (333) is positioned to contact the second flange (346). In a partial locking position, the second ball (345) received in the lower ball receiving portion (3412) is positioned at a location corresponding to the pusher groove (332) of the first pusher (330). Accordingly, the second ball (345) received in the lower ball receiving portion (3412) of the second push rod (341) is seated in the pusher groove (332) of the first pusher (330). Additionally, the second ball (345) comes into contact with the inner wall of the through hole (321) positioned above the second offset (323). Accordingly, the second ball (345) protrudes in a direction toward the first central axis (CA1) (the direction of the arrow shown inside the second ball (345) in FIG. 9B). Accordingly, as the second ball (345) slides over the second offset (323) of the housing (320), the second pusher (340) can move upward into an area where the inner diameter of the through hole (321) of the housing (320) is relatively narrow.

[0057] On the other hand, referring to FIG. 9c, which is an enlarged view of area D of FIG. 9a, the first ball (344) received in the upper ball receiving portion (3411) in a partially locked position is positioned at a location corresponding to the die groove (311), just as in the fully locked position. Additionally, in the partially locked position, the first ball (344) is positioned below the first offset (322) of the housing (320). Accordingly, the first ball (344) is pushed by the inner circumference of the housing (320) in a direction toward the first central axis (CA1) (the direction of the arrow shown inside the first ball (344) in FIG. 9c) and is seated in the die groove (311) of the die unit (310). The first ball (344) seated in the die groove (311) can restrict movement in the vertical direction of the die unit (310). Accordingly, the movement of the die unit (310) in the direction of the first central axis (CA1) is restricted by the engagement of the first ball (344) and the die groove (311). Nevertheless, referring to FIG. 9c, the die unit (310) is positioned apart from the first end (320a) of the housing (320) only because the second pusher (340) rises by a certain distance as the movement lock in the direction of the first central axis (CA1) of the second pusher (340) is released, and the lock of the die unit (310) is not released. That is, in some locked positions, the die unit (310) can only move up and down while coupled with the second pusher (340), and the movement of the die unit (310) alone in the up and down direction is restricted.

[0058] As described above with reference to FIGS. 9a to 9c, when the first pusher (330) is positioned in a partially locked position, the first ball (344) protrudes in a direction toward the first central axis (CA1), thereby restricting the movement of the die unit (310), whereas the second ball (345) also protrudes in a direction toward the first central axis (CA1), thereby allowing the movement of the second pusher (340). Accordingly, when the die unit (310) is pulled from the upper side by an external force while the first pusher (330) is positioned in a partially locked position, the die unit (310) can be dislodged from the housing (320).

[0059] FIGS. 10a to 10c are drawings illustrating the state when the first pusher (330) is placed in the unlocked position. FIG. 10a is a cross-sectional view of a die post according to one embodiment when the first pusher is placed in the unlocked position. FIG. 10b is an enlarged view of area E of FIG. 10a. FIG. 10c is an enlarged view of area F of FIG. 10a.

[0060] Referring to FIG. 10a, the case where the first pusher (330) is placed in the unlocked position means that the first pusher (330) is positioned at the top within the through hole (321) of the housing (320). In the unlocked position, the first flange (333) of the first pusher (330) is spaced apart from the snap ring (350). When the first pusher (330) is placed in the unlocked position, the first spring (360) and the second spring (370) are compressed to the maximum, so the tensile elastic force applied by the first spring (360) and the second spring (370) to the housing (320), the first pusher (330), and the second pusher (340) can be maximum. When the first pusher (330) is placed in the unlocked position, the die unit (310) and the second pusher (340) can move freely in the direction of the first central axis (CA1).

[0061] Referring to FIG. 10b, which is an enlarged view of region E in FIG. 10a, in the unlocked position, the first pusher (330) is positioned at the top within the through hole (321). In the unlocked position, the first flange (333) of the first pusher (330) is spaced apart from the snap ring (350), and the first flange (333) is positioned to contact the second flange (346). In the unlocked position, the second pusher (340) is positioned to contact the fourth offset (325) of the housing (320). In the unlocked position, the second ball (345) received in the lower ball receiving portion (3412) is seated in the pusher groove (332) of the first pusher (330). Accordingly, the second ball (345) is maintained in a protruding state toward the first central axis (CA1) (in the direction of the arrow shown inside the second ball (345) in FIG. 10b).

[0062] Referring to FIG. 10c, which is an enlarged view of area F of FIG. 10a, the first ball (344) received in the upper ball receiving portion (3411) at the unlocked position is positioned above the first offset (322) of the housing (320). Accordingly, the first ball (344) is pushed in a direction opposite to the first central axis (CA1) (the direction of the arrow shown inside the first ball (344) in FIG. 10c) and discharged from the die groove (311) of the die unit (310). The first ball (344) discharged from the die groove (311) comes into contact with the first offset (322) of the through hole (321), and above it, movement in the vertical direction of the die unit (310) is no longer restricted. Accordingly, the die unit (310) can move freely in the direction of the first central axis (CA1).

[0063] As described above with reference to FIGS. 10a to 10c, when the first pusher (330) is positioned in the unlocked position, the first ball (344) protrudes in a direction opposite to the first central axis (CA1) to allow free movement of the die unit (310), and the second ball (345) protrudes in a direction toward the first central axis (CA1) to allow free movement of the second pusher (340). Accordingly, when the die unit (310) is pulled by an external force from above while the first pusher (330) is positioned in a partially locked position, the die unit (310) can be completely detached from the housing (320).

[0064] With reference to FIGS. 8a to 10c, the first pusher (330) is described in a chronological order in which the die unit (310) is detached from the die post (300) as it rises through the fully locked position, the partially locked position, and the unlocked position; however, the case in which the die unit (310) is fixed to the die post (300) as the first pusher (330) descends through the unlocked position, the partially locked position, and the fully locked position may be performed in the reverse order of the drawings shown in FIGS. 8a to 10c.

[0065] FIG. 11 is a perspective view of a die replacement device (40) according to one embodiment. FIG. 12 is an enlarged view of area G of FIG. 11. Hereinafter, the components of the die replacement device (40) will be described with reference to FIG. 11 and FIG. 12. The die replacement device (40) is positioned near a riveting device (e.g., riveting device (10) of FIG. 1) and can replace a die unit (e.g., die unit (310) of FIG. 3) coupled to a die post (e.g., die post (300) of FIG. 3) of the riveting device (10).

[0066] Referring to FIGS. 11 and 12, the die replacement device (40) may include a die sensing module (41), a push module (42), a magazine module (43), and a die grip module (44). The die sensing module (41) can detect whether the die post of the riveting device (10) (e.g., the die post (300) of FIG. 3) has entered a replacement position (S) for replacing the die unit (e.g., the die unit (310) of FIG. 3). The push module (42) can unlock the die unit (310) by pressing the first pusher (e.g., the first pusher (330) of FIG. 4) of the die post (300) from below upward. The pushing unit (421) of the push module (42) can move upward along a first central axis (e.g., the first central axis (CA1) of FIG. 5). The magazine module (43) can store multiple die units (310). Multiple die units (310) can be arranged in a circular manner along the circumferential direction of the magazine module (43). The magazine module (43) is configured to supply one die unit (310) at a time to the die grip module (44). When one die unit (310) is supplied from the magazine module (43) to the die grip module (44), the magazine module (43) can rotate by a certain angle to prepare for the supply of the next die unit (310). The die grip module (44) can replace the die unit (310) that has been unlocked on the die post (300) of the riveting device (10) with a new die unit (310) supplied from the magazine module (43).

[0067] Referring to FIG. 12, the die sensing module (41) may include an entry confirmation sensor (411), a die confirmation sensor (412), a mounting confirmation sensor (413), and a guide block (414). In one embodiment, the entry confirmation sensor (411) may detect whether a die post (e.g., the die post (300) of FIG. 3) has entered a replacement position (S). When the die post (300) enters the replacement position (S), the die post (300) presses the guide block (414) to move inward. At this time, the entry confirmation sensor (411) may correspond to a proximity sensor that detects whether a marker placed at a specific location inside or outside the guide block (414) has approached nearby. For example, the entry confirmation sensor (411) may be a metal detection sensor using a magnet or the like. The marker of the guide block (414) is positioned to correspond to the position of the entry confirmation sensor (411) only when the guide block (414) is moved inward, so that the entry confirmation sensor (411) may have a mechanism that reacts only when the die post (300) enters the replacement position (S) and the guide block (414) is pressed inward. In one embodiment, the die confirmation sensor (412) can detect whether the die unit (310) is placed in the correct position for replacement. Since the die grip module (44) can accurately grip the die unit (310) only when the die unit (310) is placed in the correct position on the replacement position (S), the die confirmation sensor (412) detects whether the die unit (310) is placed in the correct position. At this time, the die confirmation sensor (412) may correspond to a proximity sensor that detects whether the die unit (310) has approached the correct position. For example, the die confirmation sensor (412) may be a metal detection sensor using a magnet or the like. In one embodiment, the mounting confirmation sensor (413) may detect whether the die unit (310) is separated from the first end (e.g., the first end (320a) of FIG. 9c) of the housing (e.g., the housing (320) of FIG. 9c).Specifically, the mounting confirmation sensor (413) can detect whether the die unit (310) is unlocked at the die post (300). The mounting confirmation sensor (413) may be a light sensor. For example, as illustrated in FIG. 9c and FIG. 10c, when the first pusher (e.g., the first pusher (330) in FIG. 9a and / or FIG. 10a) is located in some locked or unlocked position, the die unit (310) is separated from the first end (320a) of the housing (320). The mounting confirmation sensor (413) irradiates light to a position corresponding to the lower surface of the die head (313) and the first end (320a) while the die post (300) is placed in the replacement position (S). When it detects that light is transmitted, it means that the die unit (310) is separated from the first end (320a), and thus the die unit (310) is unlocked from the die post (300). Therefore, if the mounting confirmation sensor (413) is a light sensor, the die unit (310) is recognized as being in a locked state when light is not transmitted, and the die unit (310) is recognized as being unlocked when light is transmitted.

[0068] FIG. 13a sequentially illustrates an example in which a die unit (310) is replaced by an automatic die replacement system (1) according to one embodiment. Referring to the upper left portion of FIG. 13a, when replacement of the die unit (310) of the die post (300) is required, the frame (100) moves near the die replacement device (40) to prepare for replacement of the die unit (310). In the replacement preparation stage, the push module (42) of the die replacement device (40) is in a lowered state, multiple die units (310) are stored in the magazine module (43), and the die grip module (44) waits in a retracted state. Referring to the upper right portion of FIG. 13a, when the replacement preparation of the die replacement device (40) is completed, the die post (300) moves together with the frame (100) in the direction of the arrow so that the die unit (310) is accurately placed at the replacement position (e.g., replacement position (S) in FIG. 12). Referring to the lower right portion of FIG. 13a, when the frame (100) moves and the die post (300) presses the guide block (414), the entry confirmation sensor (411) detects whether the die post (300) has entered the replacement position (S). Additionally, the die confirmation sensor (412) detects whether the die unit (310) is placed in the correct position. When both the entry confirmation sensor (411) and the die confirmation sensor (412) confirm that the state is normal, the pushing unit (421) of the push module (42) can rise and press the first pusher (e.g., the first pusher (330) of FIG. 4). When the first pusher (330) is pressed, the die unit (310) can be unlocked. The pushing unit (421) maintains the raised state until the die unit (310) is replaced with a new die unit (310). After that, as shown in the lower left part of FIG. 13a, the die grip module (44) advances in the direction (arrow direction) where the die post (300) is positioned and prepares to grip the die unit (310).

[0069] FIG. 13b sequentially illustrates, following FIG. 13a, an example in which a die unit is replaced by an automatic die replacement system according to one embodiment. Referring to the upper-left and lower-right portions of FIG. 13b, a mounting confirmation sensor (413) can detect whether a die unit (e.g., the die unit (310) of FIG. 13a) is unlocked from the die post (300). If the die unit (310) is unlocked from the die post (300), the die grip module (44) descends to grasp the die unit (310). Referring to the upper-right portion of FIG. 13b, the die grip module (44) holding the die unit (310) rises and retracts. Referring to the lower-left portion of FIG. 13b, the die grip module (44) descends on the magazine module (43) and drops the die unit (310) retrieved from the die post (300) into the empty space of the magazine module (43).

[0070] FIG. 13c sequentially illustrates, following FIG. 13b, an example in which a die unit is replaced by an automatic die replacement system according to one embodiment. Referring to the upper left portion of FIG. 13c, the magazine module (43) rotates by a certain angle so that a new die unit (310) can be placed at the bottom of the die grip module (44). Referring to the upper right portion of FIG. 13c, the die grip module (44) descends toward the new die unit (310) of the magazine module (43) to grasp the new die unit (310). Referring to the lower right portion of FIG. 13c, the die grip module (44), having grasped the new die unit (310), rises again to prepare to attach the die unit (310) to the die post (300). Referring to the lower left portion of FIG. 13c, the die grip module (44) advances so that the gripped die unit (310) aligns with the first central axis of the die post (300) (e.g., the first central axis (CA1) of FIG. 5).

[0071] FIG. 13d sequentially illustrates, following FIG. 13c, an example in which a die unit is replaced by an automatic die replacement system according to one embodiment. Referring to the upper left portion of FIG. 13d, the die grip module (44) places the gripped die unit (310) on the top of the die post (300). Referring to the upper right portion of FIG. 13d, when the die unit (310) is placed on the top of the die post (300), the die grip module (44) rises, and the pushing unit (421) of the push module (42) lowers. As the pushing unit (421) lowers, the first pusher of the die post (300) (e.g., the first pusher (330) of FIG. 5) also lowers and moves to a fully locked position (e.g., the position of the first pusher (330) of FIG. 8a to FIG. 8c), and accordingly, the die unit (310) can be fixed to the die post (300). Referring to the lower right and lower left parts of FIG. 13d, the die post (300) from which the die unit (310) has been replaced returns to its original position to perform riveting, and the die grip module (44) can also retract and return to its original position.

[0072] Although the technical concept of the present disclosure has been described by some embodiments and examples illustrated in the accompanying drawings, it should be understood that various substitutions, modifications, and changes may be made without departing from the technical concept and scope of the present disclosure as understood by those skilled in the art to which the present disclosure pertains. Furthermore, such substitutions, modifications, and changes should be considered to fall within the scope of the appended claims.

Claims

Claim 1 A die post of a riveting device for joining at least a first plate and a second plate by riveting, comprising: a die unit that deforms the rivet upon receiving a pressure; a housing formed along a first central axis and including a through hole comprising a first offset and a second offset, and a first end and a second end formed to face each other along the first central axis, wherein the die unit is disposed at the first end; a first pusher comprising a first push rod extending along the first central axis and being pressed by an external force applied along the first central axis on the opposite side of the die unit; and a second pusher comprising a second push rod having a pusher recess and a die recess, wherein the first pusher is pressed by being inserted into the pusher recess, wherein the first pusher has a fully locked position in which movement in the direction of the first central axis of the second pusher and the die unit is restricted within the housing, and a partially locked position in which movement in the direction of the first central axis of the second pusher is possible and movement in the direction of the first central axis of the die unit is restricted. A die post movable between a position, and an unlocked position movable in the direction of the first central axis of the second pusher and the die unit. Claim 2 In claim 1, the second pusher further comprises a second push rod including an upper ball receiving portion and a lower ball receiving portion, a first ball received in the upper ball receiving portion and a second ball received in the lower ball receiving portion, the die unit includes a die groove, the first pusher further comprises a pusher groove, and in the fully locked position, the first ball is seated in the die groove and contacts the inner wall of the through hole, and the second ball is discharged from the pusher groove and contacts the second offset, a die post. Claim 3 A die post according to paragraph 2, wherein, in the aforementioned partial locking position, the second ball is seated in the pusher groove and comes into contact with the inner wall of the through hole positioned above the second offset, thereby releasing the lock of the second pusher. Claim 4 In paragraph 3, at the unlocked position, the first ball is discharged from the die groove and comes into contact with the first offset, thereby unlocking the die unit, a die post. Claim 5 A die post according to claim 1, wherein the through hole further comprises a third offset and a first spring disposed between the second pusher and the third offset to apply a pushing force against each other; and a second spring disposed between the first pusher and the second pusher to apply a pushing force against each other, wherein when the external force is released, the first pusher returns to the fully locked position by means of the first spring and the second spring. Claim 6 An automatic die replacement system for a riveting device comprises: a riveting device for joining at least a first plate and a second plate by riveting; and a die replacement device for replacing a die unit of the riveting device, wherein the riveting device comprises: a frame having a first free end and a second free end spaced apart from each other; and An automatic die replacement system comprising a die post according to claim 1 mounted on the second free end, wherein the die replacement device includes: a die sensing module that detects whether the die post is entered; a push module that unlocks the die unit by pressing the first pusher of the die post along the first central axis; and a die grip module that replaces the die unit with a new die unit, wherein when the entry of the die post is confirmed by the die sensing module, the die replacement device unlocks the die unit by pressing the first pusher by the push module and replaces the die unit by the die grip module. Claim 7 In claim 6, the die sensing module comprises: an entry confirmation sensor that detects whether the die post has entered; a die confirmation sensor that detects whether the die unit has been placed in a correct position for replacement; and a mounting confirmation sensor that detects whether the die unit has been separated from a first end of the housing, in an automatic die replacement system.

Images