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CN-121972552-A - Processing method of grenade warhead

CN121972552ACN 121972552 ACN121972552 ACN 121972552ACN-121972552-A

Abstract

The invention discloses a processing method of a grenade warhead, belongs to the technical field of machining, and solves the technical problems of limited profile, material waste and easy die scrapping when a traditional integrated cylindrical lower die is used for stamping the grenade warhead. The stamping die comprises an upper die and a lower die, wherein the lower die comprises a left die block and a right die block which are split into halves along an axis, and a die cavity matched with the outer contour of the target grenade warhead is formed after the left die block and the right die block are folded. The invention can realize the punching processing of punching holes in a die cavity of complex contour products with equal diameter, lower size, upper size and the like twice, avoid heat loss caused by die cavity replacement, reduce the contact time between a punch and a blank, avoid hardening and tempering of the punch, greatly reduce the subsequent machining amount and simplify the machining procedure, simultaneously, the detachable lower die is convenient to repair, the die cavity can be remade by machining, and the upper die can be repaired by adopting a cladding welding technology, thereby realizing the repeated repair and utilization of the die.

Inventors

  • LI HOUTING
  • WU HAO
  • ZHANG SIYAN

Assignees

  • 山东奥源材料科技有限公司

Dates

Publication Date
20260505
Application Date
20260407

Claims (7)

  1. 1. The utility model provides a processing method of grenade warhead, adopts stamping die processing, stamping die includes cope match-plate pattern and bed die (2), bed die (2) are split type structure, including left module (21) and right module (22) that split into are halved along the axis, after folding bed die (2) form with the die cavity (3) of target grenade warhead (10) outline matching, its characterized in that, specific processing steps are as follows: s1, closing a lower die (2), namely driving and splicing a left module (21) and a right module (22) of the lower die (2) together by utilizing a hydraulic mechanism; S2, placing blanks: S21, pre-punching and positioning, namely placing a solid round steel blank (7) heated to a preset temperature in a die cavity (3), wherein a variable-diameter positioning cylinder (5) is arranged on the solid round steel blank, the diameter of the lower end of the variable-diameter positioning cylinder (5) is smaller than the inner diameter of the die cavity (3), a positioning convex edge is arranged on the variable-diameter positioning cylinder, the diameter of the upper end of the variable-diameter positioning cylinder (5) is larger than the inner diameter of the die cavity (3), a positioning hole (4) for accommodating a primary punch (6) is formed in the variable-diameter positioning cylinder (5), the solid round steel blank (7) is initially positioned by the variable-diameter positioning cylinder (6), and the variable-diameter positioning cylinder (5) is pressed down until the solid round steel blank (7) transversely deforms in the die cavity (3) until the outer contour of the solid round steel blank (7) is abutted against the inner wall of the die cavity (3); S22, processing pre-punching, namely removing the reducing positioning cylinder (5), pressing down the primary punch (6) again, directly punching a blank primarily, generating plastic deformation in the die cavity (3) by the primary punch (6), and forming the blank with a primary blind hole in the die cavity (3) by extending and deforming upwards in a cavity formed by the die cavity (3) and the primary punch (6); s3, blind hole stamping, namely controlling the upper die to stamp towards the inside of the die cavity (3) at a constant speed, enabling the blank to be subjected to plastic deformation under the constraint of the die cavity (3), and stamping blind holes with preset depth in the blank to form a preliminary shell structure of the grenade warhead (10); s4, separating the upper die from the lower die (2), separating the left die block (21) from the right die block (22), and taking out the formed grenade warhead (10) shell.
  2. 2. The method for processing the grenade warhead according to claim 1, wherein the upper die and the die cavity (3) of the lower die (2) are coaxial, and a blank with a primary blind hole is automatically centered under the lower pressure of the upper die in the stamping process, so that the subsequent uniform transmission of stamping force is ensured, and the blank is prevented from being deformed or cracked locally due to uneven stress.
  3. 3. The method for machining the grenade warhead according to claim 2, wherein after the upper die is worn, the upper die is repaired by using a cladding welding technology, the lower die (2) is worn and the die cavity surface is reprocessed by a machining mode, and the upper die and the lower die (2) are manufactured by adopting H13 hot working die steel.
  4. 4. The method for manufacturing a warhead of a grenade of claim 3, wherein the repairing of the upper mold by means of the cladding welding technique comprises the following specific steps: S101, polishing and impurity removing, namely polishing the worn part of the upper die to remove surface oxide skin, greasy dirt, rust and fatigue layers, exposing a fresh metal matrix, controlling the roughness to Ra 3.2-6.3 mu m, and improving the contact area of a cladding layer and the matrix; S102, preheating the whole upper die to 300-400 ℃, wherein the heating rate is less than or equal to 50 ℃ per hour, eliminating the internal stress of the upper die, simultaneously avoiding cold cracks generated by overlarge temperature difference during cladding, and creating conditions for diffusion combination of a molten pool and a matrix; S103, selecting an arc cladding or laser cladding process, adopting a cobalt-based alloy welding material, controlling cladding current to be 180-220A, voltage to be 22-26V and welding speed to be 5-8 mm/S, ensuring moderate molten pool temperature, and enabling cobalt-based alloy of the welding material and an upper die matrix interface to generate sufficient element diffusion to form a continuous bonding layer; s104, when multi-layer multi-channel cladding is adopted, the interlayer temperature is kept at 200-300 ℃, interlayer cooling is avoided, and meanwhile, after each channel of cladding, interlayer stress is eliminated by a light hammer, so that metallurgical bonding continuity between the layers and a matrix is ensured; S105, after cladding is completed, placing the upper die in an asbestos felt or an incubator to cool to room temperature, wherein the cooling rate is less than or equal to 30 ℃ per hour, and preventing the bonding surface from generating microcracks due to thermal stress and damaging a metallurgical bonding interface; S106, detecting after repair, namely detecting the performance of the cladding layer; S107, machining to the required size.
  5. 5. The method according to claim 4, wherein in step S103, the welding material is dried at 200-250 ℃ for 1-2 hours before use, and the moisture in the welding material is removed to avoid air holes generated during cladding.
  6. 6. The method according to claim 4, wherein in step S104, the thickness of the single layer of the cladding layer is controlled to be 0.5-1 mm, so that cracks are prevented from being generated due to stress concentration caused by the excessive thickness of the single layer of the cladding layer.
  7. 7. The method according to claim 4, wherein in step S104, the surface of the previous cladding layer is slightly remelted by the subsequent cladding layer, and coarse grain areas of the previous cladding layer are eliminated, so that the entire structure is kept uniform and fine.

Description

Processing method of grenade warhead Technical Field The invention relates to the technical field of machining, in particular to a method for machining a grenade warhead. Background The shell forming of the grenade warhead is one of core procedures of grenade processing, and a traditional stamping process generally adopts an integrated cylindrical lower die, and after a solid round steel blank is put into the cylindrical lower die, a blind hole is formed by stamping from the shell opening end of the lower die through an upper die. Because the product is required to be taken out smoothly after the integral tubular lower die is punched, the die cavity can only be designed into a taper structure with a small lower part and a large upper part, the outer surface of the shrapnel warhead after punching is inevitably provided with a fixed taper, the design of complex peripheral contours with the same diameter, the large lower part, the large upper part and the like cannot be realized, the appearance diversity of the shrapnel warhead is restricted, and the diversified requirements of the modern ammunition on aerodynamic performance, fragment killing effect and filler utilization rate are difficult to meet. Meanwhile, the integral cylindrical lower die has poor inclusion on blanks, and for combat units with special local structures or special wall thickness distribution requirements, accurate forming is difficult to realize, and the problems of stress concentration and uneven material flow easily occur in the stamping process, so that the cracking of a product shell and overlarge wall thickness deviation are caused, and the product quality and the production qualification rate are influenced. In order to solve the problem of contour limitation, the prior art adopts a process of 'multi-pass stamping and subsequent machining', namely, firstly stamping to obtain a blank with taper, and then cutting by a lathe, a milling machine and the like, but has the obvious defects that the multi-pass stamping increases the complexity of the working procedure and the production cost, a large amount of machining causes serious waste of high-value metal materials, the production period is prolonged, the internal tissue structure of a shell of a grenade warhead is damaged by cutting force and heat of the machining, the mechanical property of the material is reduced, the integral strength and explosion power of the grenade warhead are influenced, and the machining is easy to deform due to insufficient rigidity of workpieces for the grenade warhead with a thin-wall and complex bore structure, so that the qualification rate is further reduced. In addition, the body thickness of traditional integral type tube-shape bed die is restricted by the structure, and in addition the die cavity is narrow, is difficult to carry out effective restoration in narrow space after the die cavity wearing and tearing, can only directly change new mould, and use cost is high, and frequent retooling can reduce production efficiency. In addition, the traditional grenade warhead processing method generally adopts a mode of profiling firstly, then punching and then stretching, the profiling is to press a blank into a solid pier material, then transfer the solid pier material to a punching cavity for punching and then transfer the solid pier material to a stretching cavity for stretching, heat dissipation is necessarily caused in the process of transferring the die cavity, the processing rhythm is also influenced, and a plurality of sets of dies are also needed. Therefore, there is a need to develop a method for processing a grenade warhead, which can realize accurate and efficient forming while eliminating the limitation of the outer peripheral outline of the product, improve the material utilization rate and the product quality, and reduce the use cost of the die. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a processing method of a grenade warhead, which solves the technical problems of limited profile, material waste, low forming precision, poor product qualification rate and easy scrapping of a die when the grenade warhead is punched by a traditional integral cylindrical lower die, realizes the direct punching forming of the grenade warhead with a complex peripheral profile, improves the material utilization rate and the processing efficiency, realizes the repeated utilization of the die and reduces the production cost. In order to achieve the above purpose, the invention adopts the following technical scheme: The utility model provides a processing method of grenade warhead, adopts the stamping die of processing grenade warhead, includes cope match-plate pattern and bed die, the bed die adopts split type structure, the bed die includes left module and the right module of splitting into along the axis halving, and the bed die after folding forms the die cavity that matches with target grenade warhead outline. The spec