Large-upsetting-ratio bolt head forming die and forming process

Abstract

The invention discloses a large upsetting ratio bolt head forming die and a forming process, the die comprises a pre-upsetting die and a finish forging die, in the pre-upsetting die, an upper punch is arranged on an upper bottom plate, a tail punch, a material ejection punch and an adjusting pad are arranged on a lower bottom plate, a lower round die jacket is arranged on the adjusting pad, a lower die and a guide die are arranged in the lower round die jacket, and the finish forging die is arranged on the lower round die jacket. The upper bottom plate, the lower bottom plate and the material returning cross beam are connected together through pull rods, and a material returning tail punch is arranged on the material returning cross beam; in the finish forging die, an upper die plate and a guide rail are arranged on an upper bottom plate, a limiting block is arranged at the front end of the guide rail, an upper die base is arranged on the upper die plate, and an upper punch is arranged on the upper die base. A lower die, a lower round die, an ejector punch and a tail punch are arranged on the lower bottom plate, a guide die is arranged below the lower round die, and an air cylinder is arranged on the upper bottom plate. Products produced through the forming die and the forming process are stable in size and can be widely applied to production of bolts with the large upsetting ratio.

Description

Technical Field

[0001] The invention relates to a large upsetting ratio bolt head forming die and a forming process. Background Art

[0002] The upsetting ratio refers to the ratio of the length to the diameter of the part of the blank that needs to be deformed. In practical applications, the upsetting ratio directly affects the quality of the product and the service life of the mold. When the upsetting ratio is too large, longitudinal bending may occur in one upsetting, resulting in defects such as interlayers in the product. Therefore, it is urgent to design a forming die and forming process for bolts with a large head upsetting ratio, which can not only form the required shape but also avoid the above defects. Summary of the invention

[0003] In order to overcome the above-mentioned shortcomings of the prior art, the present invention proposes a large upsetting ratio bolt head forming die and forming process.

[0004] The technical solution adopted by the present invention to solve the technical problem is: a large upsetting ratio bolt head forming die, including a pre-upsetting die and a final forging die, wherein: the pre-upsetting die includes an upper bottom plate, a lower bottom plate and a material withdrawal crossbeam, an upper punch is installed on the upper bottom plate, a tail punch, a top punch and an adjustment pad are arranged on the lower bottom plate, a lower circular die jacket is arranged on the adjustment pad, a lower die and a guide die are arranged in the lower circular die jacket, the upper bottom plate, the lower bottom plate and the material withdrawal crossbeam are connected together by a pull rod, and a material withdrawal tail punch is arranged on the material withdrawal crossbeam; the final forging die includes An upper base plate, a lower base plate and a material return beam are arranged on the upper base plate, an upper template and a guide rail are arranged on the upper base plate, a limit block is arranged at the front end of the guide rail, an upper die seat is arranged on the upper template, and an upper punch is arranged on the upper die seat; a lower die, a lower circular die, a top punch and a tail punch are arranged on the lower base plate, a guide die is arranged under the lower circular die, the lower die, the lower circular die and the guide die are fixed to the lower base plate by a pressing plate, the upper base plate is arranged on a tie rod seat, the tie rod seat, the lower base plate and the material return beam are connected together by a tie rod, a cylinder is arranged on the upper base plate, and the connecting rod of the cylinder is connected to the upper template.

[0005] The present invention also provides a forming process based on a large upsetting ratio bolt head forming die, comprising the following steps:

[0006] Step 1: Saponify the rod material:

[0007] The concentrate and water are prepared into saponification liquid at a mass ratio of 250:6000. During the preparation process, the concentrate is put in first, and then water is slowly added, and the mixture is stirred continuously until it is uniform. Then, the saponification liquid is heated to 70°C to 80°C, and then the rod material is put in, and the rod material is slightly shaken to make the rod material fully contact with the saponification liquid for 10 to 20 minutes, and then dried to obtain a rod material with a white saponified film evenly covered on the surface.

[0008] Step 2: using a pre-forging die to perform preliminary forming on the bar material that has been saponified in step 1;

[0009] Step 3: Place the initially formed workpiece in step 2 into a medium frequency induction coil and heat it to 1100°C to 1200°C;

[0010] Step 4: Use a final forging die to perform final forging on the process parts heated in step 3.

[0011] Compared with the prior art, the present invention has the following positive effects:

[0012] (1) The present invention performs preliminary forming on the workpiece by using a pre-upsetting die, so that the upsetting ratio of the formed part of the workpiece head is reduced, thereby avoiding bending of the workpiece during final forging.

[0013] (2) The process of the present invention for initially forming the workpiece by a pre-forging die is a cold forging process without heating. Compared with the process of the prior art in which both upsetting steps are performed by hot upsetting, the present invention has lower energy consumption, lower process cost, and a wide range of application scenarios.

[0014] (3) The products produced by the molding die and molding process of the present invention have stable dimensions and can be widely used in the production of bolts with large upsetting ratios.

[0015] (4) The present invention improves the lubricity of the workpiece surface by performing saponification treatment on the bar material before pre-forging, making the workpiece easier to form. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0017] Figure 1 It is a structural schematic diagram of the pre-upsetting die of the present invention;

[0018] Figure 2 It is a front view of the final forging die of the present invention;

[0019] Figure 3 is a cross-sectional view of the final forging die of the present invention;

[0020] Figure 4 It is the shape of the product initially formed by the pre-upsetting die of the present invention;

[0021] Figure 5 It is the shape of the product finally formed by the final forging die of the present invention;

[0022] Reference numerals in the figures include:

[0023] (1) Pre-upsetting die:

[0024] Upper base plate 1, upper die seat 2, upper punch 3, lower die 4, lower round die jacket 5, guide die 6, ejector punch 7, adjustment pad 8, tie rod 9, lower base plate 10, tail punch 11, material return tail punch 12, material return crossbeam 13;

[0025] (2) Final forging die:

[0026] Cylinder 21, cylinder seat 22, upper base plate 23, connecting rod 24, limit block 25, pressure plate 26, lower base plate 27, pull rod 28, upper template 29, upper die seat 30, upper punch 31, upper die fixing sleeve 32, lower die 33, lower circular die 34, guide die 35, top punch 36, tail punch 37, material return beam 38, pull rod seat 39, guide rail 40. DETAILED DESCRIPTION

[0027] A large upsetting ratio bolt head forming die, comprising: a pre-upsetting die and a final forging die, wherein:

[0028] (a) The structure of the pre-upsetting die is as follows Figure 1 As shown, it includes: an upper base plate 1, an upper die base 2, an upper punch 3, a lower die 4, a lower circular die sleeve 5, a guide die 6, a material ejection punch 7, an adjustment pad 8, a pull rod 9, a lower base plate 10, a tail punch 11, a material return tail punch 12 and a material return crossbeam 13, wherein: the upper punch 3 is connected to the upper base plate 1 through the upper die base 2, the material return tail punch 12 is placed on the material return crossbeam 13, the material return crossbeam 13 is fixed to the pull rod 9 through a threaded connection, the pull rod 9 is fixed to the upper base plate 1 through a threaded connection, the upper base plate 1 is connected to the equipment slider through bolts, the lower die 4 and the lower circular die sleeve 5 are assembled together through interference fit, a guide die 6 is arranged in the lower circular die sleeve 5, the lower circular die sleeve 5 is placed on the adjustment pad 8, the adjustment pad 8 is placed on the lower base plate 10, and the tail punch 11 and the material ejection punch 7 are arranged on the lower base plate 10.

[0029] (ii) The structure of the final forging die is as follows Figure 2 and Figure 3 As shown, it includes: a cylinder 21, a cylinder seat 22, an upper base plate 23, a connecting rod 24, a limit block 25, a pressure plate 26, a lower base plate 27, a pull rod 28, an upper template 29, an upper die seat 30, an upper punch 31, an upper die fixing sleeve 32, a lower die 33, a lower circular die 34, a guide die 35, a top punch 36, a tail punch 37, a material return beam 38, a pull rod seat 39 and a guide rail 40, wherein: the upper punch 31 is connected to the upper die seat 30 through the upper die fixing sleeve 32, the upper die seat 30 is connected to the upper template 29 through screws, the upper template 29 is connected to the piston rod of the cylinder 21 through the connecting rod 24, the cylinder 21 is connected to the cylinder seat 22 through bolts, the cylinder seat 22 is fixed to the equipment slide block through bolts, the upper template 29 can slide in the guide rail 40, the guide rail 40 is connected to the upper base plate 23 through bolts, and at the front end of the guide rail 40 ( Figure 2The upper mold plate 23 is fixed to the equipment slider by bolts, the pull rod 28 is connected to the pull rod seat 39 by threads, the pull rod seat 39 is fixed to the equipment slider by bolts, the material return beam 38 is fixed to the pull rod 28 by nuts, the tail punch 37 is placed on the material return beam 38, the lower mold 33, the lower circular mold 34, the guide mold 35, and the pressure plate 26 are connected to the lower mold plate 27 by bolts, and the lower mold plate 27 is connected to the equipment workbench by bolts. When working, the cylinder 21 is initially in a retracted state, and the workpiece is placed in the lower mold 33 and positioned by the guide mold 35. Start the cylinder 21 switch to eject the cylinder 21. The cylinder 21 drives the upper template 29, the upper die seat 30, and the upper punch 31 to move through the connecting rod 24. The upper template 29 contacts the limit block 25 to stop. The press switch is started, and the equipment slider moves downward. The upper punch 31 squeezes the workpiece to form the workpiece in the lower die 33. After forming, the equipment slider moves upward to drive the pull rod 28 and the material return beam 38 upward together. After moving upward for a distance, the material return beam 38 contacts the tail punch 37 to drive the ejection punch 36 upward to eject the workpiece. After the slider returns to the position, the displacement sensor transmits a signal to link the cylinder 21 to return. The cylinder 21 drives the upper template 29, the upper die seat 30, and the upper punch 31 to move through the connecting rod 24. After the upper punch 31 moves, the material taking position is vacated for easy material taking.

[0030] The forming process of the bolt head forming die with a large upsetting ratio of the present invention comprises the following steps:

[0031] Step 1: Saponify the rod material:

[0032] The saponification liquid is prepared at a mass ratio of concentrate: water = 250: 6000. It is required to add the concentrate first, then slowly add water, and stir continuously until uniform. The saponification liquid is heated to (70-80)°C, and then the workpiece is placed in the saponification liquid with a temperature of (75±5)°C and uniform stirring, and slightly shaken to make the workpiece fully contact with the saponification liquid. The workpiece is placed for (10-20) minutes, and then dried. The product surface is required to be covered with a uniform white saponification film to improve the surface lubricity of the workpiece;

[0033] Step 2: Use a pre-forging die to initially shape the bar material that has been saponified in step 1:

[0034] (1) Install the upper punch 3 in the upper die base 2, and then connect the upper die base 2 to the upper base plate 1 through bolts; place the material return tail punch 12 on the material return crossbeam 13, and then fix the material return crossbeam 13 and the tie rod 9 together through threaded connection; set the tail punch 11 and the material return punch 7 on the lower base plate 10, and then install the lower base plate 10 and the tie rod 9 together, and then fix the tie rod 9 and the upper base plate 1 together through threaded connection;

[0035] (2) Place the guide die 6 in the lower circular die sleeve 5, and then assemble the lower die 4 and the lower circular die sleeve 5 together through interference fit, and then place the bar material that has been saponified in step 1 in the lower die 4 and position it through the guide die 6; place the lower circular die sleeve 5 on the adjustment pad 8, and then place the adjustment pad 8 on the lower base plate 10; place the lower base plate 10 on the equipment workbench, and connect the upper base plate 1 to the equipment slider through bolts;

[0036] (3) The slide block of the equipment moves downward, driving the upper punch 3 to move downward, and cooperates with the top punch 7 and the tail punch 11 to extrude the bar material so that the bar material is formed in the lower die 4;

[0037] (4) After forming, the equipment slider moves upward, driving the pull rod 9 and the material return beam 13 connected to the pull rod 9 upward, and the material return beam 13 drives the material return tail punch 12 upward. After moving up a certain distance, the material return tail punch 12 contacts the tail punch 11 and drives the top punch 7 upward to move the initially formed process parts (such as Figure 4 shown) ejected.

[0038] By replacing the upper punch 3, the lower die 4 and the guide die 6 of the pre-forging die, the product can be quickly changed; by replacing the adjustment pad 8, the height size of the head can be fine-tuned, and the adjustment is simple and convenient.

[0039] Step 3: Place the workpiece initially formed in step 2 into a medium frequency induction coil and heat it to 1100°C to 1200°C. The medium frequency induction coil is a spiral coil formed by a copper tube. When the induction coil is energized, the workpiece in the induction coil generates an induced potential and forms an induced current under the action of electromagnetic induction. The induced current overcomes the resistance of the workpiece itself to generate Joule heat, thereby heating the workpiece.

[0040] Step 4: Place the heated process parts into the final forging die for final forging:

[0041] (1) The upper punch 31 is connected to the upper die base 30 through the upper die fixing sleeve 32, the upper die base 30 is connected to the upper die plate 29 through screws, the upper die plate 29 is connected to the piston rod of the cylinder 21 through the connecting rod 24, the cylinder 21 is connected to the cylinder base 22 through bolts, and the cylinder base 22 is fixed to the device slider through bolts; the upper die plate 29 is installed in the guide rail 40, and then the guide rail 40 is connected to the upper base plate 23 through bolts, and the upper base plate 23 is fixed to the device slider through bolts; the tie rod 28 is connected to the tie rod base 39 through threads, and the tie rod base 39 is fixed to the device slider through bolts;

[0042] (2) Connect the lower die 33, the lower round die 34, the guide die 35, the pressing plate 26 and the lower bottom plate 27 together by bolts, and connect the lower bottom plate 27 to the equipment workbench by bolts; fix the material return beam 38 and the pull rod 28 together by nuts, and place the tail punch 37 on the material return beam 38;

[0043] (3) Before starting work, the cylinder 21 is in a retracted state, and then the workpiece is placed in the lower die 33 and positioned by the guide die 35;

[0044] (4) Start the cylinder switch and the cylinder 21 is pushed out. The cylinder 21 drives the upper mold plate 29, the upper mold base 30, and the upper punch 31 to move through the connecting rod 24. The upper mold plate 29 moves to the front end and stops when it contacts the limit block 25.

[0045] (5) The press switch is turned on, and the slide of the equipment moves downward, driving the upper punch 31 to move downward, and cooperate with the top punch 36 and the tail punch 37 to extrude the workpiece so that the workpiece is formed in the lower die 33;

[0046] (6) After forming, the equipment slider moves upward, driving the pull rod 28 and the material return beam 38 upward together. After moving upward for a certain distance, the material return beam 38 contacts the tail punch 37 and drives the ejection punch 36 upward to eject the workpiece;

[0047] (7) After the equipment slider returns to the position, the displacement sensor transmits a signal to the cylinder 21 to return. The cylinder 21 drives the upper mold plate 29, the upper mold base 30, and the upper punch 31 to move backward through the connecting rod 24. After the upper punch 31 moves, the material removal position is vacated for easy material removal. At this point, the final forging is completed and the final result is as follows Figure 5 The high upset ratio bolt shown.

Claims

1. A large upsetting ratio bolt head forming die, characterized in that: The invention comprises a pre-forging die and a final forging die, wherein: the pre-forging die comprises an upper bottom plate, a lower bottom plate and a material-removing crossbeam, an upper punch is installed on the upper bottom plate, a tail punch, a material-removing punch and an adjusting pad are arranged on the lower bottom plate, a lower circular die jacket is arranged on the adjusting pad, a lower die and a guide die are arranged in the lower circular die jacket, the upper bottom plate, the lower bottom plate and the material-removing crossbeam are connected together by a pull rod, and a material-removing tail punch is arranged on the material-removing crossbeam; the final forging die comprises an upper bottom plate, a lower bottom plate and a material-removing crossbeam, an upper punch is installed on the upper bottom plate, a tail punch, a material-removing punch and an adjusting pad are arranged on the lower bottom plate, a lower circular die jacket is arranged on the adjusting pad, a lower circular die jacket is arranged in the lower circular die jacket, the upper bottom plate, the lower bottom plate and the material-removing crossbeam are connected together by a pull rod, and a material-removing tail punch is arranged on the material-removing crossbeam; the final forging die comprises an upper bottom plate, a lower bottom plate and a material-removing crossbeam, an upper punch is installed on the upper bottom plate An upper template and a guide rail are set, a limit block is set at the front end of the guide rail, an upper die seat is set on the upper template, and an upper punch is set on the upper die seat; a lower die, a lower circular die, a top punch and a tail punch are set on the lower base plate, a guide die is set below the lower circular die, the lower die, the lower circular die and the guide die are fixed to the lower base plate by a pressing plate, the upper base plate is set on a tie rod seat, the tie rod seat, the lower base plate and the material return beam are connected together by a tie rod, a cylinder is set on the upper base plate, and the connecting rod of the cylinder is connected to the upper template.

2. The high upsetting ratio bolt head forming die according to claim 1, characterized in that: The upper punch of the pre-forging die is connected with the upper base plate through an upper die seat.

3. The large upsetting ratio bolt head forming die according to claim 1, characterized in that: The lower die of the pre-forging die and the lower circular die outer sleeve are assembled together through interference fit.

4. The large upsetting ratio bolt head forming die according to claim 1, characterized in that: The material-removing crossbeam of the pre-forging die is fixed together with the pull rod through a threaded connection, and the pull rod is fixed together with the upper base plate through a threaded connection.

5. The large upsetting ratio bolt head forming die according to claim 1, characterized in that: The upper punch of the final forging die is connected with the upper die seat through an upper die fixing sleeve.

6. The large upsetting ratio bolt head forming die according to claim 1, characterized in that: The cylinder of the final forging die is fixed on the upper base plate through a cylinder seat.

7. The large upsetting ratio bolt head forming die according to claim 1, characterized in that: The tie rod and the tie rod seat of the final forging die are fixed together through threaded connection, and the material withdrawal crossbeam is fixed together with the tie rod through a nut.

8. A forming process based on the large upsetting ratio bolt head forming die according to claim 1, characterized in that: The steps include: Step 1: Saponify the rod material: The concentrate and water are prepared into saponification liquid at a mass ratio of 250:6000. During the preparation process, the concentrate is put in first, and then water is slowly added, and the mixture is stirred continuously until it is uniform. Then, the saponification liquid is heated to 70°C to 80°C, and then the rod material is put in, and the rod material is slightly shaken to make the rod material fully contact with the saponification liquid for 10 to 20 minutes, and then dried to obtain a rod material with a white saponified film evenly covered on the surface. Step 2: using a pre-forging die to perform preliminary forming on the bar material that has been saponified in step 1; Step 3: Place the initially formed workpiece in step 2 into a medium frequency induction coil and heat it to 1100°C to 1200°C; Step 4: Use a final forging die to perform final forging on the process parts heated in step 3.

9. The forming process based on the large upsetting ratio bolt head forming die according to claim 8, characterized in that: In step 2, the method of using a pre-forging die to initially shape the bar material is as follows: (1) Install the upper punch in the upper die seat, then connect the upper die seat with the upper base plate by bolts, place the material return tail punch on the material return beam, then fix the material return beam and the tie rod together by threaded connection, set the tail punch and the material return punch on the lower base plate, then install the lower base plate and the tie rod together, and then fix the tie rod and the upper base plate together by threaded connection; (2) Assemble the lower die and the lower circular die jacket together through interference fit, then place the workpiece in the lower die, place the lower circular die jacket on the adjustment pad, then place the adjustment pad on the lower base plate, place the lower base plate on the equipment workbench, and connect the upper base plate to the equipment slider through bolts; (3) The equipment slider moves downward, driving the upper punch to move downward, and cooperates with the top punch and the tail punch to extrude the bar material so that the bar material is formed in the lower die; (4) After forming, the equipment slider moves upward, driving the pull rod, the material return beam and the material return tail punch upward together. After moving upward for a certain distance, the material return tail punch contacts the tail punch and drives the ejection punch upward to eject the workpiece and obtain the initially formed process part.

10. The forming process based on a large upsetting ratio bolt head forming die according to claim 8, characterized in that: In step 4, the method of using the final forging die to perform final forging on the process part is: (1) Install the upper punch on the upper template, connect the upper template to the piston rod of the cylinder through a connecting rod, connect the cylinder to the cylinder seat through bolts, fix the cylinder seat to the equipment slider, install the upper template in the guide rail, then connect the guide rail to the upper base plate through bolts, then fix the upper base plate to the equipment slider through bolts, connect the tie rod to the tie rod seat through threads, and fix the tie rod seat to the equipment slider through bolts; (2) The top punch and the tail punch are set on the lower bottom plate, and the lower die, the lower round die and the guide die are fixed on the lower bottom plate through the pressing plate, the lower bottom plate is connected to the equipment workbench through bolts, and the material return beam is fixed to the pull rod through nuts; (3) When starting work, the cylinder is in a retracted state, the upper mold plate is located at the rear end of the guide rail, and then the workpiece is placed in the lower mold and positioned by the guide mold; (4) Start the cylinder switch to push out, drive the upper template and the upper punch forward through the connecting rod, and stop when the upper template contacts the limit block. Start the press switch, the equipment slide moves downward, drive the upper punch to move downward, and cooperate with the ejector punch and the tail punch to extrude the workpiece so that the workpiece is formed in the lower die; (5) After forming, the equipment slider moves upward, driving the pull rod and the material return beam upward together, until the material return beam contacts the tail punch and drives the ejection punch upward to eject the workpiece; (6) After the equipment slider returns to the position, the displacement sensor transmits a signal to link the cylinder to return. The cylinder drives the upper template and the upper punch to move backward through the connecting rod, and then the workpiece is taken out from the vacated material taking position to obtain the final forged large upsetting ratio bolt product.

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