Cold heading die for flanging and riveting nut

Abstract

The cold heading die comprises a fixed frame and a movable frame, the fixed frame and the movable frame are fixedly connected with a first die core and a second die core respectively, a first die hole is formed in the middle of the first die core, an ejector rod connected with the fixed frame in a sliding mode is arranged in the first die hole, and a step groove is formed in the outer end of the first die core. A first forming cavity used for conducting cold heading forming on a nut blank is formed among the step groove, the first die hole and the ejector rod. A second die hole is formed in the middle of the second die core, a punching rod fixedly connected with the fixing frame is arranged in the first die hole, a protruding part used for extending into the forming groove is arranged at the outer end of the second die core, and a plurality of rib grooves are annularly distributed in the protruding part. Therefore, the cold heading forming device can achieve cold heading forming of the ribs on the flanging and riveting nut, and improves the discharging stability of the nut blank after forming.

Description

Technical Field

[0001] This utility model relates to a processing tool for riveting nuts, and in particular a cold heading die for riveting nuts. Background Technology

[0002] Traditionally, manufacturers process riveted nuts using cold heading. However, as manufacturers' demands increase, current riveted nuts also require the formation of several reinforcing ribs on the outer ring. This makes it difficult for existing cold heading equipment for riveted nuts to cold-head these ribs, thus increasing the processing difficulty for manufacturers.

[0003] On the other hand, in the existing cold heading process of riveted nuts, the nut blank is first cold-headed by the cooperation of the die core and the punch. After heading, the punch retracts and the nut blank remains in the die core. Then, the fixture extends into the gap between the die core and the punch and remains coaxial with the die core. Then, the ejector pin pushes the nut blank into the fixture, so that the fixture can carry the nut blank to the next station. However, due to the obstruction of the rib structure, if the manufacturer uses the punch to cold-head the rib, the nut blank is likely to remain on the punch after cold heading and detach from the die core along with the punch. This makes it impossible for the die to eject and clamp the nut blank in the original way. In addition, the nut blank is also likely to detach directly from the punch and fall after leaving the die core. That is, it cannot replace the ejector pin to achieve stable displacement of the nut blank, thus reducing the output stability of the riveted nut after cold heading.

[0004] Therefore, existing cold heading dies used for riveting nuts cannot process ribs and have poor output stability. Utility Model Content

[0005] The purpose of this invention is to provide a cold heading die for riveted nuts. It enables the cold heading of the ribs on the riveted nuts and improves the output stability of the nut blank after forming.

[0006] The technical solution of this utility model is as follows: A cold heading mold for riveting nuts includes a fixed frame and a movable frame. A first mold core and a second mold core are fixedly connected to the fixed frame and the movable frame, respectively. A first mold hole is formed in the middle of the first mold core. A push rod that is slidably connected to the fixed frame is provided in the first mold hole. A stepped groove is provided at the outer end of the first mold core. A first forming cavity for cold heading the nut blank is formed between the stepped groove, the first mold hole and the push rod. A second mold hole is formed in the middle of the second mold core. A punch that is fixedly connected to the fixed frame is provided in the first mold hole. A protrusion that extends into the forming groove is provided at the outer end of the second mold core. Several rib grooves are distributed in a ring on the protrusion. A limiting sleeve is provided between the first mold hole and the punch. One end of the limiting sleeve extends into the movable frame and is connected in sequence to an ejector plate, a connecting rod and a movable block. The ejector plate, connecting rod and movable block are all slidably connected in the movable frame and fit in sequence. A compression spring is provided on the outer side of the movable block. A second forming cavity that matches the first forming cavity is formed between the punch, the limiting sleeve and the protrusion.

[0007] In the aforementioned cold heading die for riveting nuts, the fixing frame is fastened to the first die core through a tapered hole. The inner side of the first die core is provided with a pressure block that is slidably connected to the fixing frame, and the outer side of the pressure block is provided with a positioning block that is threadedly connected to the fixing frame. The end of the push rod passes through the pressure block and the positioning block in sequence and is connected to a drive rod.

[0008] In the aforementioned cold heading die for riveting nuts, the fixing frame includes a first fixing bracket and a second fixing bracket that are separately arranged. The first die core, the pressure block and the positioning block are all arranged in the first fixing bracket. The second fixing bracket is located outside the positioning block and is detachably connected to the first fixing bracket. The push rod is slidably connected to the second fixing bracket.

[0009] In the aforementioned cold heading die for riveting nuts, the movable frame includes a first movable bracket and a second movable bracket that are separately arranged. The punch is fastened to the first movable bracket via a fastening block. The second movable bracket is located outside the fastening block and is detachably connected to the first movable bracket. One end of the connecting rod is located inside the second movable bracket and connected to the movable block. The other end of the connecting rod passes through the fastening block and is connected to the ejector plate.

[0010] Compared with the prior art, this utility model has the following characteristics:

[0011] (1) Through the cooperation of the protrusion and the rib groove, this utility model enables the outer ring of the nut blank to enter the rib groove after being squeezed when the nut blank is cold-forged through the first forming cavity and the second forming cavity, thereby forming the corresponding rib structure. On this basis, through the structural cooperation of the push rod, the limiting sleeve and the compression spring, the compression spring can be kept in a compressed state when the nut blank is in the cold-forging state. Thus, when the movable frame drives the punch to retract after the cold forging is completed, the compression spring can rebound and drive the limiting sleeve to be pushed out and keep it in close contact with the nut blank, thereby separating the nut blank and the second mold core. When the movable frame retracts to the position, the push rod is pushed out and cooperates with the limiting sleeve to clamp and discharge the nut blank, so that the nut blank can move to the clamping position under the pressure at both ends, thereby improving the discharge stability of the nut blank.

[0012] (2) By limiting the connection structure between the fixed frame and the first mold core, the first mold core can be installed in the fixed frame by snap-fit ​​and the first mold core is pressed by screwing in the positioning block, thereby ensuring its fixing effect while facilitating the manufacturer to install and replace the first mold core.

[0013] (3) By limiting the connection structure of the movable frame, punch and limiting sleeve, it can facilitate the assembly of the manufacturer on the one hand, and limit the shrinkage position of the limiting sleeve on the other hand, thereby ensuring the dimensional accuracy of the second forming cavity.

[0014] Therefore, this utility model can realize the cold heading of the ribs on the riveted nut and improve the output stability of the nut blank after forming. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model in its initial state;

[0016] Figure 2 This is a schematic diagram of the structure of the present invention during the forming of the nut blank;

[0017] Figure 3 yes Figure 2 A magnified view from direction A;

[0018] Figure 4 This is a schematic diagram of the structure of the nut blank after it has been discharged from the machine.

[0019] The labels in the attached diagram are as follows: 1-fixed frame, 2-movable frame, 3-first mold core, 4-second mold core, 5-ejector rod, 6-step groove, 7-punch rod, 8-protrusion, 9-limiting sleeve, 10-ejection plate, 11-connecting rod, 12-movable block, 13-compression spring, 14-pressure block, 15-positioning block, 16-drive rod, 17-fastening block, 101-first fixed bracket, 102-second fixed bracket, 201-first movable bracket, 202-second movable bracket. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0021] Example. A cold heading die for riveting nuts, configured as follows: Figure 1 As shown, the device includes a fixed frame 1 and a movable frame 2. A first mold core 3 and a second mold core 4 are fixedly connected to the fixed frame 1 and the movable frame 2, respectively. A first mold hole is formed in the middle of the first mold core 3, and a push rod 5, which is slidably connected to the fixed frame 1, is provided inside the first mold hole. A stepped groove 6 is provided at the outer end of the first mold core 3. A first forming cavity for cold heading the nut blank is formed between the stepped groove 6, the first mold hole, and the push rod 5. A second mold hole is formed in the middle of the second mold core 4, and a punch 7, which is fixedly connected to the fixed frame 1, is provided inside the first mold hole. The outer end of 4 is provided with a protrusion 8 for extending into the forming groove. The protrusion 8 is provided with a number of rib grooves distributed in a ring. A limiting sleeve 9 is provided between the first mold hole and the punch 7. One end of the limiting sleeve 9 extends into the movable frame 2 and is connected in sequence to the ejector plate 10, the connecting rod 11 and the movable block 12. The ejector plate 10, the connecting rod 11 and the movable block 12 are all slidably connected in the movable frame 2 and fit together in sequence. A compression spring 13 is provided on the outside of the movable block 12. The punch 7, the limiting sleeve 9 and the protrusion 8 form a second forming cavity that matches the first forming cavity.

[0022] The rear end of the compression spring 13 is provided with a movable frame for limiting the compression spring 13. The movable frame 2 is fixedly connected to the movable frame and moves together with the movable frame.

[0023] The fixing frame 1 is fastened to the first mold core 3 through a tapered hole. The inner side of the first mold core 3 is provided with a pressure block 14 that is slidably connected to the fixing frame 1. The outer side of the pressure block 14 is provided with a positioning block 15 that is threadedly connected to the fixing frame 1. The end of the top rod 5 passes through the pressure block 14 and the positioning block 15 in sequence and is connected to the drive rod 16.

[0024] The fixing frame 1 includes a first fixing bracket 101 and a second fixing bracket 102 that are separately arranged. The first mold core 3, the pressure block 14 and the positioning block 15 are all arranged inside the first fixing bracket 101. The second fixing bracket 102 is located outside the positioning block 15 and is detachably connected to the first fixing bracket 101. The top rod 5 is slidably connected to the second fixing bracket 102.

[0025] The movable frame 2 includes a first movable support 201 and a second movable support 202 arranged in a split manner. The punch 7 is fastened to the first movable support 201 via a fastening block 17. The second movable support 202 is located outside the fastening block 17 and is detachably connected to the first movable support 201. One end of the connecting rod 11 is located inside the second movable support 202 and is connected to the movable block 12. The other end of the connecting rod 11 passes through the fastening block 17 and is connected to the ejector plate 10.

[0026] The working principle of this utility model is as follows: In use, the fixture first transports the nut blank to be processed between the push rod 5 and the punch 7, ensuring they are concentric. Then, the movable frame 2 moves towards the fixed frame 1, and the limiting sleeve 9 pushes the nut blank during this movement, causing it to detach from the fixture and enter the first forming cavity. Once the nut blank is engaged in the first forming cavity, the limiting sleeve 9 retracts inward against the elastic force of the compression spring 13 as the movable frame 2 continues to move. Simultaneously, the punch 7 and the second mold core 4 move with the movable frame 2 to the cold heading position, cooperating with the first forming cavity to cold-head the nut blank. During the cold heading process, the nut blank in the stepped groove 6 deforms under pressure and fills the rib groove, thus forming the corresponding rib structure.

[0027] After the nut blank is cold-forged, the punch 7 retracts along with the movable frame 2, while the limiting sleeve 9 continuously pushes the nut blank under the rebound action of the compression spring 13, causing the nut blank to separate from the punch 7 under the pushing action. After the punch 7 and the nut blank separate, the drive rod 16 drives the push rod 5 to push outward, so that the nut blank is pushed out to the outside of the stepped groove 6 under the squeezing action of the push rod 5 and the limiting sleeve 9, and maintains its concentric position during the movement, so that the fixture can stably clamp the nut blank to the next station and ensure its output stability.

Claims

1. A cold heading die for riveting nuts, characterized in that: The device includes a fixed frame (1) and a movable frame (2). A first mold core (3) and a second mold core (4) are fixedly connected to the fixed frame (1) and the movable frame (2), respectively. A first mold hole is formed in the middle of the first mold core (3). A push rod (5) that is slidably connected to the fixed frame (1) is provided in the first mold hole. A stepped groove (6) is provided at the outer end of the first mold core (3). A first forming cavity for cold heading of the nut blank is formed between the stepped groove (6), the first mold hole and the push rod (5). A second mold hole is formed in the middle of the second mold core (4). A punch (7) that is fixedly connected to the fixed frame (1) is provided in the first mold hole. The outer end of the second mold core (4) is provided with a stepped groove (6). The end is provided with a protrusion (8) for extending into the forming groove, and the protrusion (8) is provided with a number of rib grooves distributed in a ring; a limiting sleeve (9) is provided between the first mold hole and the punch (7), one end of the limiting sleeve (9) extends into the movable frame (2) and is connected in sequence to the ejector plate (10), the connecting rod (11) and the movable block (12), the ejector plate (10), the connecting rod (11) and the movable block (12) are all slidably connected in the movable frame (2) and fit together in sequence, and a compression spring (13) is provided on the outside of the movable block (12), and a second forming cavity is formed between the punch (7), the limiting sleeve (9) and the protrusion (8) to cooperate with the first forming cavity.

2. The cold heading die for riveting nuts according to claim 1, characterized in that: The fixing frame (1) is fastened to the first mold core (3) through a tapered hole. The inner side of the first mold core (3) is provided with a pressure block (14) that is slidably connected to the fixing frame (1). The outer side of the pressure block (14) is provided with a positioning block (15) that is threadedly connected to the fixing frame (1). The end of the top rod (5) passes through the pressure block (14) and the positioning block (15) in sequence and is connected to a drive rod (16).

3. The cold heading die for riveting nuts according to claim 2, characterized in that: The fixing frame (1) includes a first fixing bracket (101) and a second fixing bracket (102) arranged in a split manner. The first mold core (3), the pressure block (14) and the positioning block (15) are all arranged inside the first fixing bracket (101). The second fixing bracket (102) is located outside the positioning block (15) and is detachably connected to the first fixing bracket (101). The top rod (5) is slidably connected to the second fixing bracket (102).

4. The cold heading die for riveting nuts according to claim 1, characterized in that: The movable frame (2) includes a first movable support (201) and a second movable support (202) arranged in a split manner. The punch (7) is fastened to the first movable support (201) via a fastening block (17). The second movable support (202) is located outside the fastening block (17) and is detachably connected to the first movable support (201). One end of the connecting rod (11) is located inside the second movable support (202) and connected to the movable block (12). The other end of the connecting rod (11) passes through the fastening block (17) and is connected to the ejector plate (10).

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