A cold heading forming apparatus and method for a vehicle body sleeve blank

Abstract

The application discloses a cold heading forming equipment and method for a vehicle body sleeve blank, and relates to the technical field of molds.The cold heading forming equipment comprises a front punch and a rear punch, a puncher is arranged in the front punch, a blanking hole and an avoiding hole are arranged in the puncher, a front punch pad and a blanking pad are coaxially arranged in the front punch, a mold core, a push tube and a top rod that are matched with the workpiece are arranged in the rear punch, a guide part is arranged on the blanking pad, the guide part moves along the waste material discharging direction by one thickness of the waste material with the action of extruding the waste material, and is limited after moving;when the end of the guide part reaches the end of the blanking pad, the waste material extruding the guide part moves, the guide part is reset after a delay, and the end waste material of the waste material stack falls off.The cold heading forming equipment and method for the vehicle body sleeve blank are characterized in that a slide rod that can axially slide is arranged behind the puncher, the waste material after punching is righted, the waste material can be discharged along the hole position in a forward direction, and scratches on the hole wall are avoided, so that pits are not caused.

Description

Technical Field

[0001] This invention relates to the field of mold technology, specifically to a cold heading forming equipment and method for car body sleeve blanks. Background Technology

[0002] See Figure 1 This is a cold heading process for body sleeve blanks, mainly including blanking, shaping, shaping and pre-forming hole drawing and positioning holes, reverse extrusion hole drawing and forming hole drawing and positioning holes, upsetting and forming steps and reverse extrusion of inner holes, extrusion of through holes, upsetting of flanges and end face teeth. In step 6, when extruding through holes, the waste material flows to the end with the step due to the stroke on both sides. The conventional design is to open a blanking hole on the punch, the diameter of which is the same as the inner diameter of the through hole, to expel the waste material. An axial clearance hole with a diameter slightly larger than the blanking hole is set in the blanking hole. The length of the blanking hole is generally at least one waste material thickness (depending on the material strength and sheet thickness, etc.), but it should not be too long, as it is easy to jam the material. There is a step between the feed hole and the clearance hole. This process equipment is used horizontally (it is difficult to remove waste in the vertical direction), meaning that waste will be piled up horizontally and pushed out. Because the step formed by the clearance hole causes the waste to tilt after being pushed out of the feed hole, the waste piece will tilt forward in the direction of movement, and its center of gravity will drop. Since the waste piece is circular, it will not completely tilt, but will maintain a certain tilt angle (depending on the ratio of the waste piece diameter to the clearance hole diameter). In this tilted state, the edge of the waste piece will come into contact with the wall of the clearance hole. Because the edge of the waste piece is sharp after extrusion, the force acting on the inner wall of the clearance hole will cause scratches or pits over time, which is not conducive to the subsequent discharge of waste. To address this, we propose a cold heading forming equipment and method for car body sleeve blanks. Summary of the Invention

[0003] The purpose of this invention is to provide a cold heading forming equipment and method for vehicle body sleeve blanks, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a cold heading forming equipment and method for a car body sleeve blank, comprising a front die and a rear die. A punch is installed in the front die, and the punch has a blanking hole and a clearance hole. A front punch pad and a blanking pad are coaxially arranged in the front die with the punch. The rear die is provided with a die core adapted to the workpiece, as well as a push tube and an ejector bar. A guide part is provided on the blanking pad. The guide part abuts against the end face of the waste sheet in the direction of movement and moves along the waste discharge direction by the thickness of a waste sheet as the waste is extruded. After the movement, it is limited. When the end of the guide part reaches the end of the blanking pad, the waste extrudes the guide part and moves it. After a delay, the guide part resets, causing the waste at the end of the stacked waste sheet to fall off.

[0005] Preferably, the guiding part includes a slide rod that is coaxial with the blanking pad and slides through the blanking pad. One end of the slide rod abuts against the stacked waste pieces, and the other end is provided with a guide tube. A limiting block is provided on the side wall of the slide rod located inside the guide tube. A guide strip and a limiting strip are fixed on the inner wall of the guide tube. The guide strip and the limiting strip are staggered, and the axial distance between adjacent limiting strips is the same as the thickness of a single waste piece. A delay part is provided at the end of the guide tube that is axially away from the rear die. It is used to generate friction to delay the reset of the slide rod. The slide rod is subjected to a torque and / or a thrust that tends to move towards the rear die along the axial direction. The limiting strip and the limiting block abut against each other to balance the torque.

[0006] Preferably, the guide strip and the limiting strip are made of rigid material and fixed to the inner wall of the guide cylinder, and the two are interwoven to form a wave shape.

[0007] Preferably, the guide strip and the limiting strip are integrally formed and can be elastically deformed, and adjacent guide strips are spaced apart along the axial direction of the guide cylinder.

[0008] Preferably, the initial distance between the contact end of the guide rod and the end of the top rod in the maximum stroke state of the initial extrusion is L1, the thickness of a single waste piece is N, and the maximum axial spacing of a single waste piece along the guide cylinder in the maximum tilt state when the material drop hole moves towards the clearance hole is L2, where L2 > L1 > N.

[0009] Preferably, when the slide bar is reset under the action of the delay part, it is reset to the limit position of the previous adjacent limit bar.

[0010] Preferably, the sliding rod has a contact plate rotatably connected to its contact end, and the contact plate directly contacts the waste material sheet.

[0011] Preferably, a method of using a cold heading forming equipment for a car body sleeve blank includes the following steps:

[0012] S1: Punching, the front and rear punches close together, and the ejector pin pushes the scrap into the punch.

[0013] S2: Stacking. Under continuous punching action, the scrap sheet moves the slide bar axially to the other end according to the number of punchings and limits it, so that the scrap sheet keeps the axis horizontal near the punching state.

[0014] S3: Discharge. When the end of the slide bar reaches the position of the discharge pad, the slide bar reciprocates during punching, and the individual waste pieces fall off and are discharged here.

[0015] S4: Reset. Manually reset the slide bar when it is not in use for a long time and the mold is not removed.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] This invention provides an axially sliding slide bar behind the punch to straighten the waste material after punching, allowing it to be discharged in the correct direction along the hole, thus avoiding scratches on the hole wall, which would cause pits and affect the service life.

[0018] Under the action of various structures, the slide bar of the present invention can move and limit according to a predetermined distance to straighten the waste sheet without applying external force, so that the waste sheet can be stably stacked and moved, thereby improving the stability of material discharge.

[0019] The present invention provides a delay section after the slide bar to make the slide bar reciprocate, discharging the waste material one by one, avoiding simultaneous discharge and thus preventing jamming. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall process flow structure of the workpiece according to the present invention;

[0021] Figure 2 For the corresponding Figure 1 A schematic diagram of the mold structure for each workstation;

[0022] Figure 3 This is a half-sectional schematic diagram of the overall structure of the present invention;

[0023] Figure 4 This is a schematic diagram of the internal state of a punch during the punching process.

[0024] Figure 5 This is a schematic diagram showing the natural changes in the state of waste material inside a punch.

[0025] Figure 6 A schematic diagram of a half-section structure of one embodiment of the guide tube;

[0026] Figure 7 This is a schematic diagram showing the two structural states of the limiting strip and the guide strip;

[0027] Figure 8 This is a schematic diagram of the state structure of another embodiment inside the guide tube.

[0028] In the diagram: 1. Front punch; 2. Rear punch; 21. Die core; 22. Push tube; 23. Ejector bar; 11. Punch; 12. Front punch pad; 13. Blanking pad; 101. Blanking hole; 102. Clearance hole; 131. Guide section; 1301. Slide rod; 1302. Guide cylinder; 1303. Limiting block; 1304. Guide strip; 1305. Limiting strip; 1306. Delay section; 1307. Contact plate. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 This invention provides a technical solution: a cold heading forming device for a car body sleeve blank, including a front die 1 and a rear die 2. The front die 1 is provided with a punch 11, a front punch pad 12 and a blanking pad 13. The rear die 2 is provided with a die core 21, a push tube 22 and an ejector rod 23. The front die 1 and / or the rear die 2 move towards each other to perform stamping. The rear die 2 is provided with a spring at the end of the die core 21 opposite to the front die 1, which is used to push the die core 21 out of the rear die 2 by a certain distance. A push tube 22 is also provided at the center of the axis of the rear die 2. One end of the push tube 22 is part of the forming surface of the cavity, and the other end is connected to the ejector rod on the rear die 2. Under the action of the ejector rod, the workpiece is pushed out of the cavity, thereby facilitating the removal of the workpiece.

[0031] The punch 11 in the front punch die 1 is a cylindrical body with two coaxial through holes, namely the blanking hole 101 and the clearance hole 102. The inner diameter of the blanking hole 101 is the same as the diameter of the waste material punched in the workpiece, which is used for extrusion. The clearance hole 102 is to facilitate the collection of the waste material after it is punched out of the blanking hole 101. The front punch pad 12 also has a through hole with a diameter larger than that of the clearance hole 102. A downwardly inclined blanking channel is provided on the blanking pad 13, which falls under the action of gravity.

[0032] See Figure 5 ,exist Figure 5 In state A1, the scrap material has just finished punching and entered the critical state of the clearance hole 102. At this time, due to the restriction of the discharge hole 101, the axis can still be kept horizontal. After being pushed out further, the following occurs: Figure 5 As shown in A2, the material sheet will tilt at the step between the clearance hole 102 and the material drop hole 101, depending on the step height difference. Because the sheet is thin, it will tip over. Figure 5 The scrap on the left side of A2 remains tilted because the hole is circular. It slides inside the punch 11 under the action of the subsequent scrap and the top rod 23. The edge of the scrap is a right angle. When it slides in a tilted state, it will produce scratches. The accumulation of scratches will cause obstacles and thus affect the normal progress of subsequent punching.

[0033] See Figure 3A guide part 131 is provided on the blanking pad 13. The working end of the guide part 131 contacts the scrap material of the workpiece punching. During each punching, the working end of the guide part 131 is pushed a distance equal to the thickness of the scrap material. After being pushed, the guide part 131 will automatically limit itself to prevent the scrap material from being pushed out in the opposite direction (it is basically impossible to push it out in the opposite direction due to the limitation of the step, but this avoids pushing it out in extreme cases). When the scrap material reaches the blanking channel of the blanking pad 13, the scrap material at the outermost end needs to fall out and be discharged. Therefore, when the working end of the guide part 131 reaches this position, it is pushed and then reset with a delay to allow time for the scrap material to fall and avoid the scrap material from being unable to fall due to being held on both sides.

[0034] The cold heading process for the integrated step anti-slip sleeve includes the following steps:

[0035] Step 1, Material preparation: Make cylindrical blanks by cutting the cold heading coil into individual cylindrical blanks through the cutting station of the cold heading machine;

[0036] Step 2, Shaping: The cylindrical blank is extruded through the cold heading die at the first station to form a rounded bottom corner and a conical surface of about 10° at the top;

[0037] Step 3, Shaping and preforming the hole positioning hole: Flip the blank obtained in Step 2 180° and place it into the cold heading mold of the second station. Extrude the rounded corner of the bottom conical surface of about 10° and the rounded corner of the top to extrude the hole positioning hole.

[0038] Step 4, reverse extrusion and forming of hole positioning holes: The blank obtained in step 3 is flipped 180° and placed into the cold heading mold of the third station for reverse extrusion. Step holes are extruded on the bottom hole positioning holes, and the top hole positioning holes are formed.

[0039] Step 5, Upsetting and Forming Steps and Back-Extruding Inner Holes: Place the blank obtained in Step 4 into the cold heading mold at the fourth station for upsetting, forming step features on the workpiece, and extruding the step holes on the top drawing hole positioning hole.

[0040] Step 6, Extrusion through hole: Place the blank obtained in step 5 into the cold heading die at the fifth station to pierce through the entire workpiece. After the through part becomes punching waste and is discharged, a circular through hole is obtained.

[0041] Step 7, Upsetting and forming the flange and end face serrations: Place the blank obtained in step 6 into the cold heading mold at the fifth station, upset and form the top flange structure, pressurize the end face of the sleeve, and fill the serration groove of the punch to form the serration structure.

[0042] This solution refers to the mold used in the extrusion through-hole during process step 6 described above.

[0043] See Figure 3 , Figure 4 , Figure 5, Figure 6 , Figure 7 and Figure 8 The guiding part 131 includes a slide rod 1301, which passes through the material drop pad 13 and can slide axially. One end of the slide rod 1301 contacts the waste material piece, and the other end is slidably connected to the guide cylinder 1302. A limiting block 1303 is provided on the edge of the end side wall of the slide rod 1301 inside the guide cylinder 1302. The limiting block 1303 can be a block-shaped body protruding from the outer side wall of the slide rod 1301. The limiting strip 1305 restricts the limiting block 1303, so that it moves one unit at a time when pushed by the waste material piece. (The limiting distance between two adjacent limiting strips 1305, i.e. the thickness of a single waste piece), the limiting strip 1305 limits the limiting block 1303 to prevent it from resetting and pushing the waste in the opposite direction. A delay part 1306 is provided at the inner end of the guide tube 1302. The delay part 1306 is used to delay the reset of the slide rod 1301 when the waste can fall to the outside. That is, the movement of the slide rod 1301 at the end is reciprocating, so that the waste pieces fall one by one. Before reaching the end, the waste pieces are stacked in sequence with the axis horizontally stacked.

[0044] See Figure 8 In one embodiment, the limiting strip 1305 and the guide strip 1304 are integrated elastic levers and are inclined along the axial direction, so that the limiting block 1303 is limited after passing through the limiting strip 1305 and the guide strip 1304 and will not reset. In this embodiment, the delay part 1306 can also be an elastic lever, with an angle different from the integrated setting of the limiting strip 1305 and the guide strip 1304, or it can be the same. An elastic element, such as a spring, is provided at the end of the guide cylinder 1302 to generate thrust. When the slide rod 1301 reaches a position close to the end, the reaction force of the spring increases, which will break through the limitation of the delay part 1306 and reset. However, the reset force is not set too high, so it is not... The instantaneous rapid reset is completed within the gap between workpiece loading and unloading, thus preventing the stacked waste pieces from tipping over. In the production process in the workshop, it is generally a continuous production state, and the machine will only stop due to the completion of the batch or equipment failure. Therefore, the slide bar 1301 does not need to be reset to the initial state during continuous production. It only needs to reciprocate at the last position. When the machine stops, it is a non-production state. In cases where the mold itself is not involved, the slide bar 1301 does not need to be fully reset if the mold is not disassembled. However, if the mold is involved, it can be manually pushed back to its original position after installation (one end of the slide bar 1301 can be inserted through or a push rod can be set on the side wall to penetrate the guide tube 1302, which is not shown in the figure).

[0045] See Figure 6 and Figure 7In another embodiment, distinct from the previous one, the limiting strip 1305 and the guide strip 1304 are separately provided. The guide strip 1304 is spirally or quasi-spirally inclined on the inner wall of the guide cylinder 1302 to guide the limiting block 1303. The limiting strip 1305 is provided between two adjacent guide strips 1304, and the limiting strip 1305 restricts the reset of the sliding rod 1301. That is, a torsion spring is provided between the sliding rod 1301 and the guide cylinder 1302. The torsion spring causes the sliding rod 1301 to reset due to the rotation of the guide strip 1304, and then be restricted by the limiting strip 1305. The limiting strip 1305 and the guide strip 1304 can be continuously provided or disconnected. The schematic diagram of their state on the unfolded surface of the inner surface of the guide cylinder 1302 is shown below. Figure 7 In the B1 or B2 shape, that is, the limiting strip 1305 can be inclined or not inclined. In this embodiment, the delay part 1306 has a certain inclination angle. That is, unlike the limiting strip 1305, the delay part 1306 contacts and generates friction, so that it slowly resets under the action of the torsion spring, thereby delaying. In the circumferential direction, there is an angle difference between the ends of the delay part 1306 and the limiting strip 1305, so that the delay part 1306 can reset to the previous limiting strip 1305 after the delay.

[0046] See Figure 4 and Figure 5 The initial state of slide bar 1301 is far from the mold closing state, and the end of ejector bar 23 is in the extrusion state.

[0047] The distance from the end face of the slide bar 1301 is L1, and the thickness of a single scrap piece is N, where L1 > N, so that a certain gap can be left to avoid generating a reaction force and to facilitate the next punching. The maximum axial spacing of the scrap piece in the step of the drop hole 101 and the clearance hole 102 when it is naturally tilted is L2, where L2 > L1. That is, even with a gap, the slide bar 1301 will also restrict the scrap piece to prevent it from tilting to its maximum state, so that the edge will abut against and slide against the clearance hole 102, causing scratches. The more horizontal the axis of the scrap piece is, the better.

[0048] See Figure 4 A contact plate 1307 is provided at the end of the slide rod 1301. The contact plate 1307 is rotatably connected to the slide rod 1301 so that it will not drive the waste material when it is rotating in the reset state, and can rotate better.

[0049] A method for using a cold heading forming equipment for a car body sleeve blank includes the following steps:

[0050] S1: Punching, the front punch 1 and the rear punch 2 close, and the ejector 23 pushes the waste into the punch 11;

[0051] S2: Stacking, under continuous punching action, the scrap piece moves the slide bar 1301 axially to the other end according to the number of punchings and limits it, so that the scrap piece keeps the axis horizontal near the punching state.

[0052] S3: Discharge. When the end of the slide bar 1301 reaches the position of the material drop block 13, the slide bar 1301 reciprocates during punching, and the individual waste pieces fall off and are discharged here.

[0053] S4: Reset. When the slide bar 1301 is not used for a long time and is not required for mold removal, manually reset it.

[0054] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0055] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A cold heading forming device for a vehicle body sleeve blank, comprising a front punch (1) and a rear punch (2), a puncher (11) is installed in the front punch (1), a blanking hole (101) and a relief hole (102) are arranged in the puncher (11), a front punch pad (12) and a blanking pad (13) are coaxially arranged with the puncher (11) in the front punch (1), a die core (21) matched with the workpiece, a push tube (22) and a top rod (23) are arranged in the rear punch (2), characterized in that: The blanking pad (13) is provided with a guide (131), which is in contact with the end surface of the moving direction of the waste sheet and moves along the waste discharge direction by one waste sheet thickness with the action of extruding the waste, and is limited after moving. When the end of the guide (131) reaches the end of the blanking pad (13), the waste sheet extrudes the guide (131) after moving, and the guide (131) is reset in time, so that the end waste sheet of the waste sheet stack falls off. The guide (131) includes a sliding rod (1301) coaxial with the blanking pad (13) and sliding through the blanking pad (13), one end of the sliding rod (1301) is in contact with the waste sheet stack, the other end is provided with a guide sliding cylinder (1302), and the side wall of the one end of the sliding rod (1301) located in the guide sliding cylinder (1302) is provided with a limiting block (1303). The inner wall of the guide sliding cylinder (1302) is fixed with a guide sliding strip (1304) and a limiting strip (1305), the guide sliding strip (1304) and the limiting strip (1305) are staggered, the axial spacing between adjacent limiting strips (1305) is the same as the thickness of a single waste sheet, and a delay part (1306) is arranged at the end of the guide sliding cylinder (1302) axially away from the rear punch (2), which is used to generate friction force to delay the reset of the sliding rod (1301). The sliding rod (1301) is subjected to a torque and / or a pushing force along the axial direction tending to move towards the rear punch (2), and the limiting strip (1305) is in contact with the limiting block (1303) to balance the torque.

2. A cold heading forming apparatus for a body can blank according to claim 1, characterized in that: The guide sliding strip (1304) and the limiting strip (1305) are of rigid material and are fixed on the inner wall of the guide sliding cylinder (1302), and the two are staggered and connected to form a wave shape.

3. A cold heading apparatus for forming a body can blank according to claim 1, wherein: The guide sliding strip (1304) and the limiting strip (1305) are integrally arranged and can elastically deform, and adjacent guide sliding strips (1304) are arranged at intervals along the axial direction of the guide sliding cylinder (1302).

4. A cold heading machine for forming a body can blank according to claim 1, characterized in that: The distance between the contact end of the sliding rod (1301) in the initial state and the end of the ejector rod (23) in the maximum stroke state of the first extrusion is L1, the thickness of a single waste sheet is N, and the maximum axial distance of a single waste sheet in the maximum inclination state when moving from the blanking hole (101) to the avoiding hole (102) is L2, L2>L1>N.

5. A cold heading apparatus for forming a body can blank according to claim 2, wherein: When the sliding rod (1301) is reset under the action of the delay part (1306), it is limited to the previous adjacent limiting strip (1305).

6. A cold heading machine for forming a body can blank according to claim 1, characterized in that: The contact end of the sliding rod (1301) is rotationally connected with a contact disc (1307), which is directly in contact with the waste sheet.

7. A method of using a cold upset forming apparatus for a vehicle body can production according to any one of claims 2 to 6, characterized in that: The method comprises the following steps: S1: punching, the front punch (1) and the rear punch (2) are closed, and the ejector rod (23) pushes the waste sheet into the punch (11); S2: stacking, under the action of continuous punching, the waste sheet moves the sliding rod (1301) along the axial direction to one end by the number of punching and limits it, so that the waste sheet maintains the axial horizontal state close to the punching; S3: discharging, when the end of the sliding rod (1301) reaches the position of the blanking pad (13), the sliding rod (1301) reciprocates during punching, and the single waste sheet falls off and is discharged at this time; S4: reset, when the mold is unloaded, the slide rod (1301) is reset manually.

Images