A device for fastening a self-piercing rivet

Abstract

A rivet fastening device is provided to prevent the inversion of short-dimensional SPRs. A cylindrical rivet fastening device used for feeding and fastening rivets comprises an inlet portion that receives and supports the rivet, a first feeding portion extending from the inlet portion, a second feeding portion extending to the opposite side of the inlet portion relative to the first feeding portion, and an outlet portion extending to the opposite side of the first feeding portion relative to the second feeding portion to support the rivet fed from the second feeding portion. The inlet portion and the first feeding portion have at least two first slots diagonally, and the second feeding portion and the outlet portion have a greater number of second slots than the slots of the inlet portion and the first feeding portion, and are configured such that when the rivet is fed from the inlet portion and enters the first feeding portion, the first slot opens and the second slot closes.

Description

Technology Field

[0001] The present disclosure relates to an apparatus for feeding and fastening self-piercing rivets (SPR), and in particular to a collet for feeding and fastening SPRs. Background Technology

[0002] In recent years, a technology that mechanically joins base materials using SPR has been utilized as a replacement for direct joining technologies such as spot welding. An SPR is a semi-cylindrical rivet having a peaked or dish-shaped head and a semi-cylindrical leg that forms a cavity beneath the head.

[0003] The drive-in of the SPR is generally performed in the following sequence. First, the upper plate (e.g., aluminum plate) and lower plate (e.g., high-strength steel plate) to be joined are clamped by the die and nose piece of the fastening device. When the SPR provided within the nose piece is driven in by a punch, the leg portion of the SPR pierces and penetrates the upper plate. When the leg portion of the SPR that has penetrated the upper plate enters the lower plate and the lower surface of the lower plate comes into contact with the bottom of the die, the bottom of the die cavity pushes the lower plate back. As a result, the leg portion of the SPR receives a reaction force from the lower plate and spreads out annularly within the lower plate without penetrating it. As the leg portion of the SPR spreads out, a mechanical interlock is formed, and the upper plate and lower plate are mechanically joined. The die and nose piece are separated from the members to be joined, and the joining is completed.

[0004] A conventional collet that feeds an SPR by being placed inside a nose piece, as disclosed in Patent Document 1, consists of two left and right collets arranged in an arc shape and secured by installing an O-ring at the outlet. The collets are tapered from the inlet toward the outlet so that the inner diameter becomes elliptical when the two left and right collets are arranged. When a rivet with a perfect circle passes through the arranged collets, the O-ring expands to the diameter of the rivet flange and opens, causing the gap between the two collets to increase. Consequently, in the case of a short SPR of 5 mm or less (an SPR with a shaft length shorter than the flange diameter), an inverted space is created. Furthermore, an expansion load is applied to the O-ring, and after a certain number of uses, the O-ring is damaged by heat at the edge of the machined groove for installation and breaks. During the operation of the SPR, since the collet is housed inside the nose piece, it is difficult to detect that the O-ring has broken; if continued, the collet is unable to hold and support the rivet, causing it to invert. Prior art literature

[0005] Japanese Patent Publication No. 4355380 The problem to be solved

[0006] Therefore, the objective of the present invention is to provide a rivet fastening device that prevents the inversion of short-dimensional SPRs and is resistant to thermal damage. means of solving the problem

[0007] To achieve this objective, one aspect of the present invention is,

[0008] It is a cylindrical rivet fastening device used for feeding and fastening rivets, and

[0009] An inlet portion that accepts and supports the above rivet, and

[0010] A first feeding section connected from the above-mentioned inlet section and configured to feed the above-mentioned rivet, and

[0011] A second feeding section configured to feed the rivet, connected to the first feeding section on the opposite side from the inlet section, and

[0012] An outlet portion that is connected to the second feeding portion on the opposite side from the first feeding portion and supports the rivet fed from the second feeding portion.

[0013] Equipped,

[0014] The above-mentioned inlet section and the above-mentioned first feed section have at least two first slots diagonally, and

[0015] The second feed section and the outlet section have a greater number of second slots than the slots having the inlet section and the first feed section, and

[0016] When the rivet is fed from the inlet and enters the first feeding section, the first slot is opened and the second slot is closed.

[0017] In the above-described rivet fastening device, preferably, the first slot extends to the second feeding section.

[0018] In the above-described rivet fastening device, preferably, the wall thickness of the second feeder is configured to be thinner than the wall thickness of the first feeder.

[0019] In the above-described rivet fastening device, preferably, the wall thickness of the outlet portion is configured to be thicker than the wall thickness of the second feed portion.

[0020] In the above rivet fastening device, preferably, the length of the second slot is configured to be longer than the length of the first slot.

[0021] In the above rivet fastening device, preferably, the number of the first slots is 2 and the number of the second slots is 6.

[0022] In the above-described rivet fastening device, preferably, the inlet portion has a slot width narrower than the first feeding portion, and the outlet portion has a slot width narrower than the second feeding portion.

[0023] In the above-described rivet fastening device, preferably, the inlet portion, the first feeding portion, the second feeding portion, and the outlet portion are formed by integral molding.

[0024] Another aspect of the present invention is a case in which the rivet fastening device is disposed on the inside, and

[0025] When the above rivet reaches the above exit portion, the second slot of the above exit portion is configured to widen outward in the diameter direction and come into contact with the inner surface of the above case. Effects of the invention

[0026] According to the present invention, it is possible to provide a rivet fastening device that prevents reversal during the feeding of a short-dimensional SPR and is resistant to thermal damage. Brief explanation of the drawing

[0027] Figure 1 is a drawing illustrating the configuration of a system (10) for feeding and fastening rivets. FIG. 2 is a drawing showing a cross-section AA of a system (10) for feeding and fastening rivets of FIG. 1. FIG. 3 is a drawing illustrating the configuration of a collet (100) according to one embodiment of the present invention. FIG. 4 is a drawing showing the front view (a), back view (b), left side view (c), right side view (d), top view (e), bottom view (f), and cross-sectional view (g) of the collet (100) of FIG. 3, respectively. FIG. 5 is a drawing illustrating an aspect of feeding an SPR (204) using a collet (100) according to one embodiment. Specific details for implementing the invention

[0028] Hereinafter, embodiments for implementing the present invention will be described with reference to the attached drawings. Identical or similar components are assigned identical or similar reference numbers to omit redundant descriptions. Additionally, the scale of the drawings is not uniform in order to facilitate understanding of the present invention.

[0029] [Configuration of a system for feeding and fastening rivets]

[0030] With reference to FIGS. 1 and 2, the configuration of a system (10) for feeding and fastening rivets will be described. FIG. 1 is a partial perspective view of a portion in which a member to be fastened is held and supported by the system (10) for feeding and fastening rivets, and FIG. 2 is a cross-sectional view AA of FIG. 1.

[0031] As illustrated in FIG. 1, the system (10) has a receiver (101) for receiving self-drilling rivets (SPR) supplied one by one from a rivet supply device, a punch (102) for striking the supplied SPR, a punch holder (103) for holding and supporting the punch (102) so as to be slidably movable, a nose piece (104) for protecting the linear movement of the punch (102) during striking, a die (105) that contacts a part of the member to be fastened, and a C-frame (106) for holding and supporting the die (105), one end of which is connected to the die (105). Additionally, although not shown in the drawing, the other end of the C-frame (106) is structured to hold and support an unillustrated housing that accommodates the punch holder (103).

[0032] As illustrated in FIG. 2, the receiver (101) has a passage (101b) through which SPR supplied from the rivet supply device passes, and a rivet passage prevention wall (101c) to stop the advance of SPR passing through the passage (101b). The rivet supply device supplies SPR using compressed air pressure, and the receiver (101) is equipped with exhaust ports (101a, 101d) for discharging the compressed air. A concave portion (101e) is formed in the upper part of the receiver (101), and the tip of the punch holder (103) is fitted into the concave portion (101e). The receiver (101) has a convex portion (101f) that protrudes into the concave portion (101e) on a part of the wall surface forming the concave portion (101e), and on the wall surface opposite to the convex portion (101f), a through groove (101g) formed to be concavely indented from the concave portion (101e). A concave portion (101h) is formed in the lower part of the receiver (101), and the nose piece (104) is pressed into the concave portion (101h) while the collet (100) is inserted into the nose piece (104).

[0033] The punch holder (103) holds and supports the punch (102) so that it can slide. Although not shown, the structure is such that an unillustrated housing that accommodates the punch holder (103) is held and supported by one end of the C frame (106). At the tip of the punch holder (103), a concave groove (103a) formed to fit the shape of the convex portion (101f) of the receiver (101) and a through groove (103b) formed to face the through groove (101g) of the receiver (101) when the punch holder (103) and the receiver (101) are fitted together are formed. The concave groove (103a) extends the tip of the punch holder (103) in a circumferential direction, for example, 1 / 4 of a circumference, and also extends along the axial direction toward the tip of the punch holder (103). The convex portion (101f) of the receiver (101) is guided from the leading groove of the punch holder (103) and slides along the axial direction and also rotates in the peripheral direction, so as to be in the state shown in FIG. 2. The through groove (101g) of the receiver (101) and the through groove (103b) of the punch holder (103) face each other to integrally form a through hole. A rod-shaped lock member not shown is inserted into this through hole, thereby fixing the punch holder (103) and the receiver (101).

[0034] The punch (102) is a rod-shaped member for striking the supplied SPR (204) into the members to be joined (201, 202). When the SPR (204) is sent out until it comes into contact with the rivet passage prevention wall (101c) and is held and supported by the rivet passage prevention wall (101c) and a rivet holding support member such as a spring not shown, the punch (102) strikes the SPR (204) into the members to be joined (201, 202). The striking operation of the punch (102) is performed by a rivet striking device.

[0035] As shown in FIG. 2, the nose piece (104) is installed in the receiver (101) by pressing its root portion into the recess (101h) of the receiver (101). The interior of the nose piece (104) is hollow to accommodate the collet (100), and with the collet (100) inserted into the cavity of the nose piece (104), the nose piece (104) is pressed into the recess (101h) of the receiver (101). The tip of the nose piece (104) contacts the upper plate (201) and clamps the upper plate (201) and the lower plate (202) together with the die (105).

[0036] The receiver (101), punch holder (103), and nose piece (104) are integrally made to move linearly along the axial direction of the nose piece (104) by means of an unillustrated driving means such as a compression coil spring.

[0037] The die (105) is a member that supports the upper plate (201) and the lower plate (202). In order to allow the leg portion (204b) to be spread when the SPR (204) is driven in, the die (105) has a cavity (105a) in its head portion with a diameter larger than the outer diameter of the leg portion (204b) of the SPR (204).

[0038] One end of the C-frame (106) holds and supports the die (105) as shown in FIG. 2. The other end of the C-frame (106) is fixed to a housing (not shown) that accommodates the punch holder (103). In the striking of the SPR, a strong force of typically 20 to 100 kN is applied to the SPR, so the C-frame (106) is made of a material having a rigidity such that the alignment does not collapse even when such a strong force is applied.

[0039] [Composition of the rivet fastening device (collet)]

[0040] FIG. 3 is a perspective view illustrating the configuration of a rivet fastening device (collet (100)) according to one embodiment of the present invention. FIG. 4 illustrates a front view (a), a rear view (b), a left side view (c), a right side view (d), a top view (e), a bottom view (f), and a cross-sectional view (g) of the collet (100), respectively.

[0041] The collet (100) is cylindrical in shape overall and has an inlet section (200), a first feed section (220), a second feed section (230), and an outlet section (240) in order from the upstream side where the SPR is supplied, and these can be formed by integral molding.

[0042] Two slots (212) are diagonally inserted into the inlet section (200) and the first feed section (220). As shown in FIG. 3, the slots (212) may extend to a portion of the second feed section (230) on the side of the first feed section (220). As an example of the slots (212), the length is 30 mm and the width is 1.2 mm. In addition, the portion of the inlet section (200) containing the slots (212) is subjected to drawing processing to reduce the slot width, and the diameter of the rivet inlet in the cross section is formed in an elliptical shape. Furthermore, the slots (212) are formed along the major axis of this ellipse, thereby separating the inlet section (200) into two parts. The length of the minor axis of this ellipse is smaller than the diameter of the flange of the SPR, so that the SPR can be held and supported in the inlet section (200) and configured so that it does not fall into the collet (100). In addition, the opening shape of the inlet section (200) is such that the flange section of the SPR is fitted in, and the structure is such that the SPR received from the receiver (101) does not create a space for the SPR to be reversed at the inlet section (200).

[0043] When the SPR held and supported in the inlet section (200) is pressed in the cylindrical axial direction of the collet (100) by the punch (102), the gap between the two pieces of the slot (212) increases, and the opening of the inlet section (200) widens from an elliptical direction to a short axis direction. And as the inner diameter in the short axis direction of the inlet section (200) widens to the flange diameter of the SPR, the SPR can pass through the flange portion axially along the inner diameter of the inlet section (200).

[0044] The first feed section (220) is connected to the downstream side in the direction in which the SPR flows with respect to the inlet section (200) and feeds the SPR inserted from the inlet section (200). The first feed section (220) has a drawing process performed on the part on the inlet section (200) side. When the slot (212) of the inlet section (200) opens and the SPR passes through, the inner diameter of the first feed section (220) leading to the inlet section (200) is configured to widen in conjunction with this, and the SPR is configured so that the flange portion passes along the inner surface of the first feed section (220).

[0045] The second feed section (230) is connected to the first feed section (220) on the opposite side from the inlet section (200) and feeds SPR to the outlet section (240). The second feed section (230) has a slot (222) extending from the outlet section (240) side, divided into six cylindrical sections, and is shaped like six claws. In one example, the length of the slot is 39 mm and the width is 1 mm. Additionally, it is preferable that the slot (212) formed from the inlet section (200) to the first feed section (220) extends to the second feed section (230). For example, in this case, the slot (212) implemented in the second feed section (230) is formed at a position that divides the six slots (222) into three each. That is, the portion of the second feeder (230) on the side of the first feeder (220) has both two slots (212) and six slots (222) formed. By configuring it in this way, when the upstream two-part section (slot (212)) opens as the SPR enters from the inlet section (200), the downstream six-part claw section (slot (222)) from the second feeder (230) to the outlet section (240) is easily closed. In addition, this function can be easily enabled by making the number of downstream slots (222) greater than the number of upstream slots (212), or by making the length of the downstream six-part claw section (slot (222)) longer than the length of the upstream two-part section (slot (212)).

[0046] The second feeding section (230) is made elastic by making the wall thickness thinner than that of the inlet section (200) and the first feeding section (220).

[0047] The outlet section (240) is configured to support the SPR fed from the second feeding section (230) when fastening it. The outlet section (240) is subjected to drawing processing similar to the inlet section (200), and the SPR is prevented from passing through the outlet section (240) unless the SPR is compressed by the punch (102).

[0048] The outlet section (240) has a thicker wall than the second feed section (230), so that when the SPR passes through, the gap with the inner diameter of the nose piece (104) covering the outside is reduced, and the structure is designed so that it does not become wider than necessary.

[0049] The slot (212) of the inlet section (200) has been processed by drawing, and the slot width is narrower than the slot (212) of the first feed section (220). Also, the slot (222) of the outlet section (240) has been processed by drawing, and the slot width is narrower than the slot (222) of the second feed section (230). By configuring it in this way, in the inlet section (200) and the outlet section (240), when the SPR passes through the inlet section (200), the inlet section (200) widens and the outlet section (240) narrows, so that sufficient tension is applied to the SPR from the outside, allowing it to be stably held and supported.

[0050] As described above, by forming slots on the upstream and downstream sides of the collet (100), the structure is designed so that when the SPR passes through the collet (100), tension is applied to an appropriate degree while maintaining the directionality of the SPR at any position. Because of this, it is possible to load the SPR up to the outlet (240) of the collet (100) while maintaining its up-and-down directionality.

[0051] In addition, in this embodiment, assuming the material has high rigidity, the upstream slots (212) are set to 2 and the downstream slots (222) are set to 6, but the number of slots may be increased, such as by setting the slots (212) to 4 and the slots (222) to 8. In this case, the material may be resin, for example. By making the structure such that the number of slots is increased, it becomes possible to feed more smoothly while providing stable inner tension to the SPR compared to the conventional 2 slots.

[0052] As described above, in this embodiment, the SPR is structured in such a way that it is difficult to reverse by suppressing the widening of the tip diameter of the collet (100). In addition, each of the slots (212 and 222) formed in the collet (100) is configured to be manufactured by integral molding rather than extending along the entire axial direction of the collet (100), so that the O-ring, which was conventionally considered necessary, is not required.

[0053] [SPR Feeding Operation Using Collet]

[0054] FIG. 5 is a drawing illustrating an aspect of feeding an SPR (204) using a collet (100) according to one embodiment.

[0055] FIG. 5(a) illustrates a situation in which an SPR (204) supplied from a receiver (101) is held and supported in an inlet section (200). In this situation, the SPR (204) can be held and supported in the inlet section (200) because the outer diameter of the flange portion of the SPR is larger than the inner diameter of the inlet section (200).

[0056] FIG. 5(b) illustrates a situation in which the SPR (204) is pressed downward by the punch (102) and reaches the first feed section (220). In this situation, when the SPR (204) is extruded by the punch (102), the upper two-part section (slot (212)) of the collet (100) opens and the lower six-part section (slot (222)) closes. Reference numeral 300 in FIG. 5(b) illustrates a situation in which the upper two-part section (slot (212)) is open, and reference numeral 310 illustrates a situation in which the lower six-part section (slot (222)) is closed. By having the upper and lower slots separately in this way, the structure is designed to apply tension to an appropriate degree while maintaining the directionality of the SPR at all times.

[0057] In FIG. 5(c), the SPR (204) is further compressed downward by the punch (102) and passes through the first feed section (220) and the second feed section (230) to reach the exit section (240). In this situation, as the SPR (204) passes, the six divisions (slots (222)) of the exit section (240) are formed with thick wall thickness and are open up to the inner diameter of the nose piece (104), and the SPR (204) can be loaded up to the exit section (240), which is the tip of the collet (100), while maintaining its vertical directionality, thereby enabling fastening using the SPR (204). In this way, the outlet portion (240) of the collet (100) is positioned on the inner side of the nose piece (104) which functions as the case of the collet (100). When the SPR (204) reaches the outlet portion (240), the outer surface in the diameter direction of the outlet portion (240) comes into contact with the inner surface of the nose piece (104) and cannot expand beyond this, thereby supporting the SPR (204) so ​​that it cannot be inverted within the outlet portion (240), and also ensuring the centering of the SPR (204) during fastening.

[0058] As described above, an embodiment and example of a collet for feeding and connecting an SPR according to the present invention have been explained. It is readily understood that the present invention is not limited to the above examples and that various modifications can be made thereto. Furthermore, as long as such modifications fall within the scope of the matters described in each claim of the patent claims and matters equivalent thereto, they are naturally included within the technical scope of the present invention. Although the above examples involved feeding an SPR as the target, this is merely an example, and the present invention is not limited to this specific embodiment. Explanation of the symbols

[0059] 10: System 100: Chocolate 101: Receiver (Nosepiece Support) 101a: Exhaust port 101b: Passage 101c: Rivet passage barrier 101d: Exhaust pipe 101e: Concave part 101f: Convex part 101g: Through groove 101h: Concave part 102: Punch 103: Punch Holder 103a: Concave groove 103b: Through groove 104: Nose Piece 105: Die 105a: Cavity 106: C frame 200: Entrance 212: Part 2 220: 1st Dispatch Department 222: 6-part section 230: 2nd Transmission Department 240: Exit section 201: Top plate 202: Bottom plate 204: Self-perforating rivets

Claims

Claim 1 A cylindrical rivet fastening feeding device used for feeding and fastening rivets, comprising an inlet portion that receives and supports the rivet, a first feeding portion connected from the inlet portion and configured to feed the rivet, a second feeding portion connected to the first feeding portion on the opposite side from the inlet portion and configured to feed the rivet, and an outlet portion connected to the second feeding portion on the opposite side from the first feeding portion and supporting the rivet fed from the second feeding portion, wherein the inlet portion and the first feeding portion have at least two first slots diagonally, and the second feeding portion and the outlet portion have a greater number of second slots than the slots of the inlet portion and the first feeding portion, and wherein when the rivet is fed from the inlet portion and enters the first feeding portion, the first slot opens and the second slot closes. Claim 2 A rivet fastening feed device according to claim 1, wherein the first slot extends to the second feed section. Claim 3 A rivet fastening feeder according to claim 1 or 2, wherein the wall thickness of the second feeder is thinner than the wall thickness of the first feeder. Claim 4 A rivet fastening feeder according to claim 1 or 2, wherein the wall thickness of the outlet portion is thicker than the wall thickness of the second feed portion. Claim 5 A feed device for rivet fastening according to claim 1 or 2, wherein the length of the second slot is longer than the length of the first slot. Claim 6 A feed device for rivet fastening according to claim 1 or 2, wherein the number of the first slots is 2 and the number of the second slots is 6. Claim 7 A rivet fastening feeding device according to claim 1 or 2, wherein the inlet portion has a narrower slot width than the first feeding portion and the outlet portion has a narrower slot width than the second feeding portion. Claim 8 A rivet fastening feed device according to claim 1 or 2, wherein the inlet portion, the first feed portion, the second feed portion, and the outlet portion are formed by integral molding. Claim 9 A case having the rivet feeding device described in claim 1 or 2 disposed on the inside, wherein when the rivet reaches the outlet portion, the second slot of the outlet portion widens outward in the diameter direction and comes into contact with the inner surface of the case.

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