CN101195142A - A mold and forming process for deep-drawing cup-shaped parts of metal sheets - Google Patents

The invention discloses a die assembly of metal plate deep-drawing cup shells and shaping process. The invention comprises an upper die holder and a lower die holder, wherein a punch and a cavity die which are mutually corresponded are respectively arranged on the upper die holder and the lower die holder, a discharging screw which is connected with the upper die holder and a flanging spring which is sleeved on the discharging screw are arranged on the outer side of the punch, a blank holder is arranged on the lower end of the discharging screw, a holding frame which is fixedly connected with the lower die holder is arranged on the outer side of the cavity die, a conical pushing block and a rubber pad are arranged in turn in the holding frame from top to bottom, a conical enclasping element which is matched with the punch is arranged in the conical pushing block, a spring holder is arranged on the lower end of the lower die holder, a material squeezing spring is arranged in the spring holder, and a push rod which is extended through the rubber pat, the conical pushing block, and a conical clamping element is arranged on the upper end of the material squeezing spring. The invention carries out enclasping along the side-wall direction during the deep-drawing process of cup shells, material flowing tendency can be changed flexibly and actively, which enables wall thickness to be changed evenly, maximum thinning-out quantity on a dangerous cross portion during the process for drawing can be minimized and drawing breakage can be avoided.

一种金属板料拉深杯形件的模具及成型工艺 A mold and forming process for deep-drawing cup-shaped parts of metal sheets

技术领域technical field

本发明属于材料成形及模具领域，尤其涉及一种金属板料拉深杯形件的模具及成型工艺。The invention belongs to the field of material forming and moulds, and in particular relates to a mold and a forming process for a sheet metal drawing cup-shaped part.

背景技术Background technique

金属板料冲压成形已被广泛的应用于许多领域。如何充分利用和发挥材料的成形性能、发掘新的成形工艺与方法，提高成形效率与质量是整个行业面临的一个重要课题，也是国内外塑性加工界研究的热点。杯形件拉深成形是一种在金属板料冲压成型领域应用最广泛的成型工艺，在杯形件拉深成型过程中，目前主要通过优化组合工艺参数和模具结构参数来提高板料的拉深成形效率和质量，尤其是对压边力、凸模圆角、凹模圆角、润滑条件等工艺参数和模具结构的研究。然而就现在取得的技术和成果而言，迄今仍停留在感性认识阶段，工艺参数与模具结构的确定与优化往往需要长时间的反复试验，总结归纳而获得，提高杯形件拉深效率及质量的效果并不明显。由于杯形件拉深过程中，拉深件变形不均匀，壁厚分布不均，其拉深破裂总是在壁厚最大变薄处最先产生从而导致整个拉深成形失败，而且拉裂缺陷的产生与拉深过程中金属的流动趋势有很大的关系。Sheet metal stamping has been widely used in many fields. How to make full use of the forming properties of materials, discover new forming processes and methods, and improve forming efficiency and quality is an important topic facing the entire industry, and it is also a hot research topic in plastic processing circles at home and abroad. Cup-shaped deep drawing is the most widely used forming process in the field of sheet metal stamping and forming. Deep forming efficiency and quality, especially the research on blank holder force, punch fillet, die fillet, lubrication conditions and other process parameters and die structure. However, as far as the current technology and achievements are concerned, they are still at the stage of perceptual understanding. The determination and optimization of process parameters and mold structure often require long-term repeated experiments, which can be obtained by summarizing and summarizing to improve the drawing efficiency and quality of cup-shaped parts. effect is not obvious. Due to the uneven deformation and uneven wall thickness distribution of the cup-shaped parts during the deep-drawing process, the deep-drawing cracks always occur first at the place where the wall thickness is the largest and thinner, which leads to the failure of the entire deep-drawing forming, and the cracking defects The generation of the metal has a lot to do with the flow tendency of the metal during the deep drawing process.

发明内容Contents of the invention

本发明的目的在于提供一种通过主动控制金属流动趋势从而有效提高拉深成形效率和质量的金属板料拉深杯形件的模具及成型工艺。The object of the present invention is to provide a mold and a forming process for a sheet metal deep drawing cup-shaped part that can effectively improve the drawing forming efficiency and quality by actively controlling the metal flow tendency.

为达到上述目的，本发明的模具是：包括上模座和下模座，上模座与下模座通过导柱相连接，在上模座和下模座上分别设置有相互对应的凸模和凹模，凸模的外侧设置有与上模座相连接的卸料螺钉及套装在卸料螺钉上的压边弹簧，在卸料螺钉的下端设置有压边圈，在凹模的外侧设置有与下模座固定连接的容框，容框内自上而下依次设置有锥形推块和橡胶垫，锥形推块内还设置有与凸模相配合的锥形抱紧件，在下模座的下端设置有弹簧座，且在弹簧座内设置有顶料弹簧，在顶料弹簧上端设置有贯穿橡胶垫、锥形推块和锥形抱紧件的顶杆，在项杆外套有弹簧。In order to achieve the above object, the mold of the present invention is: comprising an upper mold base and a lower mold base, the upper mold base and the lower mold base are connected by guide posts, and the upper mold base and the lower mold base are respectively provided with corresponding punches And the die, the outer side of the punch is provided with a discharge screw connected to the upper die base and a blank holder spring set on the discharge screw, a blank holder is provided at the lower end of the discharge screw, and a blank holder is provided on the outside of the die. There is a container frame that is fixedly connected with the lower die base. Conical push blocks and rubber pads are arranged in sequence from top to bottom in the container frame. Conical push blocks are also provided with tapered clamping parts that match the punch. The lower end of the mold base is provided with a spring seat, and a jacking spring is set in the spring seat, and a ejector rod that runs through the rubber pad, the tapered push block and the tapered holding member is provided at the upper end of the spring seat. spring.

本发明的凸模及卸料螺钉均通过上模固定块与上模座相连接；导柱上还套装有导套；锥形抱紧件为三瓣大小、形状相同的抱紧块构成，该抱紧块沿周向均匀分布；顶杆为一上端的直径小于下端直径的台阶状圆柱体，大径与小径之间通过锥面过渡；锥形抱紧件(6)外侧的锥面角为28°～35°；锥形抱紧件抱紧深度为杯形件拉深后的高度40％～45％。Both the punch and the discharge screw of the present invention are connected to the upper die base through the upper die fixing block; the guide post is also covered with a guide sleeve; The clamping blocks are evenly distributed along the circumference; the push rod is a stepped cylinder whose upper end diameter is smaller than that of the lower end, and the major diameter and the minor diameter are transitioned through a tapered surface; the cone surface angle on the outside of the tapered clamping member (6) is 28°～35°; the tightening depth of the tapered clamping piece is 40%～45% of the height of the cup-shaped piece after drawing.

本发明采用的工艺为：上模座下行，压边弹簧和压边圈将板料压紧开始拉深，开始拉深时，在顶料弹簧及弹簧共同作用，顶杆的大直径部位处在锥形抱紧件的中心小孔内，抱紧块向外张开着，上模座继续下行，材料逐渐被拉入凹模内，此时顶杆随之后退，顶料弹簧及弹簧被压缩，随着凸模继续下行，凸模带动工件压到锥形抱紧件的底部，推动锥形抱紧件下移，此时顶杆的小直径部位进入锥形抱紧件的孔内，橡胶垫的夹紧，锥形推块下移，三瓣抱紧块同时径向靠拢，将工件抱紧，凸模继续下行，橡胶垫的压缩，工件底部及侧壁在抱紧状态下随着顶杆、锥形抱紧件、锥形推块同时刚性下移进行拉深，直至拉深至下死点位置，当上模座向上返程时，橡胶垫、顶料弹簧、弹簧的共同作用，顶杆、锥形抱紧件及锥形推块同时上移，橡胶垫处于正常状态时锥形推块停止运动，顶杆、锥形抱紧件相对锥形推块继续向上运动，凸模向上拉，将工件逐渐顶出锥形抱紧件和凹模，同时锥形抱紧件依次在顶杆大直径部分的作用下，向外张开，为下次拉深做好准备。The process adopted in the present invention is as follows: the upper mold base goes down, the blank-holder spring and the blank-holder ring press the sheet material and start deep drawing. In the small hole in the center of the tapered clamping part, the clamping block is opened outwards, the upper die base continues to move downward, and the material is gradually pulled into the die, at this time, the ejector rod then retreats, and the ejector spring and the spring are compressed , as the punch continues to go down, the punch drives the workpiece to press to the bottom of the conical clamping part, pushing the conical clamping part down, at this time the small diameter part of the ejector rod enters the hole of the conical clamping part, and the rubber Clamping of the cushion, the conical push block moves down, and the three-lobed clamping blocks radially move closer at the same time to hold the workpiece tightly. The rod, the conical holding part, and the conical push block rigidly move downward at the same time for deep drawing, until the deep drawing reaches the bottom dead point position. The rod, the conical holding part and the conical pushing block move upward at the same time, and when the rubber pad is in a normal state, the conical pushing block stops moving, the ejector rod, the conical holding part continue to move upward relative to the conical pushing block, and the punch pulls upwards , the workpiece is gradually ejected out of the conical clamping part and the die, and at the same time, the conical clamping part is opened outwards under the action of the large diameter part of the ejector rod in turn to prepare for the next deep drawing.

由于本发明在拉深过程中给工件的侧壁部位施加一定抱紧力，使工件能够抱紧凸模，增加凸模与工件间的摩擦力，改变侧壁的金属流动趋势，防止变薄区材料尤其是危险断面的进一步变薄，使壁厚变厚处更多地参与变形，拉深件壁厚分布趋向均匀，从而推迟了开裂的产生。提高了材料的拉深变形均匀程度，减少拉深次数，成形效率也将大大提高。Since the present invention applies a certain clamping force to the side wall of the workpiece during the deep drawing process, the workpiece can hold the punch tightly, increase the friction between the punch and the workpiece, change the metal flow trend of the side wall, and prevent the thinning area The further thinning of the material, especially the dangerous section, makes the thickened part more involved in the deformation, and the wall thickness distribution of the drawn part tends to be uniform, thus delaying the occurrence of cracks. The uniformity of deep-drawing deformation of the material is improved, the number of deep-drawing is reduced, and the forming efficiency will also be greatly improved.

附图说明Description of drawings

图1是本发明的整体结构示意图。Fig. 1 is a schematic diagram of the overall structure of the present invention.

具体实施方式Detailed ways

下面结合附图对本发明作进一步详细说明。The present invention will be described in further detail below in conjunction with the accompanying drawings.

参见图1，包括上模座8和下模座1，上模座8与下模座1通过导柱2相连接，导柱2上还套装有导套10，在上模座8和下模座1上分别设置有相互对应的凸模12和凹模7，凸模12的外侧设置有与上模座8相连接的卸料螺钉11及套装在卸料螺钉11上的压边弹簧13，在卸料螺钉11的下端设置有压边圈14，凸模12及卸料螺钉11均通过上模固定块9与上模座8相连接，在凹模7的外侧设置有与下模座1固定连接的容框3，容框3内自上而下依次设置有锥形推块5和橡胶垫4，锥形推块5内还设置有与凸模12相配合的锥形抱紧件6，锥形抱紧件6为三瓣大小、形状相同的抱紧块构成，该抱紧块沿周向均匀分布，在下模座1的下端设置有弹簧座17，且在弹簧座17内设置有顶料弹簧18，在顶料弹簧18上端设置有贯穿橡胶垫4、锥形推块5和锥形抱紧件6的上端的直径小于下端直径的台阶状圆柱体顶杆15，在项杆15外套有弹簧16。Referring to Fig. 1, it includes an upper mold base 8 and a lower mold base 1, the upper mold base 8 and the lower mold base 1 are connected through a guide post 2, and a guide sleeve 10 is also set on the guide post 2, and the upper die base 8 and the lower die base The base 1 is respectively provided with a corresponding punch 12 and a die 7, and the outside of the punch 12 is provided with a discharge screw 11 connected to the upper die base 8 and a blank holder spring 13 set on the discharge screw 11, The lower end of the discharge screw 11 is provided with a blank holder 14, the punch 12 and the discharge screw 11 are connected with the upper die base 8 through the upper die fixing block 9, and the outer side of the die 7 is provided with the lower die base 1. The fixedly connected container frame 3 is provided with a conical push block 5 and a rubber pad 4 sequentially from top to bottom in the container frame 3, and a conical clamping member 6 that matches the punch 12 is also provided in the conical push block 5 , the conical clamping member 6 is composed of clamping blocks with the same size and shape as three petals. The ejector spring 18 is provided with a step-shaped cylinder ejector rod 15 which runs through the upper end of the rubber pad 4, the tapered push block 5 and the tapered holding member 6. The diameter of the upper end is smaller than the diameter of the lower end. Overcoat has spring 16.

本发明的成型工艺如下：上模座8下行，在压边弹簧13和压边圈14的作用下将板料压紧开始拉深，开始拉深时，在顶料弹簧18及弹簧16的共同作用下，顶杆15的大直径部位处在锥形抱紧件6的中心小孔内，抱紧块向外张开着。上模座8继续下行，材料逐渐被拉入凹模7内，此时顶杆15随之后退，顶料弹簧18及弹簧16被压缩。随着凸模12继续下行，凸模12带动工件压到锥形抱紧件6的底部，推动锥形抱紧件6下移。此时顶杆15的小直径部位进入锥形抱紧件6的孔内，由于橡胶垫4的夹紧力较大，锥形推块5下移量小，在其内锥面的作用下，三瓣抱紧块同时径向靠拢，将工件抱紧。凸模12继续下行，由于橡胶垫4的压缩作用，抱紧力进一步增大，工件底部及侧壁在抱紧状态下随着顶杆15、锥形抱紧件6、锥形推块5同时刚性下移进行拉深，直至拉深至下死点位置。当上模座8向上返程时，在橡胶垫4、顶料弹簧18、弹簧16的共同作用下，顶杆15、锥形抱紧件6及锥形推块5同时上移，当橡胶垫4处于正常状态时锥形推块5停止运动，顶杆15、锥形抱紧件6相对锥形推块5继续向上运动，再加上凸模12上的向上拉力(摩擦力)作用，将工件逐渐顶出锥形抱紧件6和凹模7。同时锥形抱紧件6依次在顶杆15大直径部分的作用下，向外张开，为下次拉深做好准备。The forming process of the present invention is as follows: the upper mold base 8 descends, and under the action of the blank holder spring 13 and the blank holder ring 14, the sheet material is pressed tightly to start deep drawing. Under the action, the large-diameter portion of the push rod 15 is in the central aperture of the tapered clamping part 6, and the clamping block is outwardly opened. The upper mold base 8 continues to descend, and the material is gradually pulled into the die 7. At this time, the ejector rod 15 retreats subsequently, and the ejector spring 18 and the spring 16 are compressed. As the punch 12 continues to descend, the punch 12 drives the workpiece to be pressed to the bottom of the conical gripping part 6, pushing the conical gripping part 6 to move down. At this time, the small diameter portion of the ejector rod 15 enters the hole of the conical clamping member 6. Due to the large clamping force of the rubber pad 4, the downward movement of the conical push block 5 is small, and under the action of its inner cone surface, The three-lobed holding blocks move radially together at the same time to hold the workpiece tightly. The punch 12 continues to descend, and due to the compression effect of the rubber pad 4, the clamping force further increases, and the bottom and side walls of the workpiece are simultaneously locked together with the ejector rod 15, the tapered clamping part 6, and the tapered push block 5 in the clamped state. Rigid downward movement for deep drawing until the bottom dead center position is reached. When the upper mold base 8 returns upwards, under the joint action of the rubber pad 4, the ejector spring 18, and the spring 16, the ejector rod 15, the conical holding member 6 and the conical push block 5 move upward at the same time, when the rubber pad 4 When it is in a normal state, the conical push block 5 stops moving, and the ejector rod 15 and the conical holding member 6 continue to move upward relative to the conical push block 5, coupled with the upward pulling force (friction force) on the punch 12, the workpiece Gradually eject the tapered clamping part 6 and the die 7. Simultaneously, the conical holding part 6 is opened outwards under the action of the large-diameter part of the push rod 15 successively, so as to get ready for the next drawing.

本发明在下模容框内有一套抱紧机构，主要由锥形抱紧件6、锥形推块5、顶杆15、橡胶垫4、弹簧16组成。锥形抱紧件6为三瓣大小、形状相同的抱紧块构成，该抱紧块沿周向均匀分布，当合拢在一起时，其外形构成一个完整的锥面，与锥形推块5内形相配合，而其内形构成了一个带底的圆柱孔，与拉深零件外形配合对拉深零件进行抱紧。The present invention has a set of clamping mechanism in the lower mold frame, which mainly consists of a tapered clamping part 6, a tapered push block 5, a push rod 15, a rubber pad 4, and a spring 16. The conical holding part 6 is composed of three lobes of the same size and shape. The holding blocks are evenly distributed along the circumference. The inner shape matches, and its inner shape forms a cylindrical hole with a bottom, which cooperates with the shape of the deep-drawn part to hold the deep-drawn part tightly.

以下为发明要点：The following are the key points of the invention:

为保证有效抱紧，对锥形抱紧件6的内形尺寸应有一定的精度要求，根据凸模外形尺寸及材料厚度取为(d+t)_-Δ，d为凸模直径，t为料厚。Δ取值应适当，取值太大，使板料在厚度方向产生塑性变薄，影响工件壁厚尺寸要求；取值太小，抱紧不可靠，一般取Δ＝(1％～2％)t。In order to ensure effective tightness, there should be certain accuracy requirements for the inner dimension of the conical tightness 6, which is taken as (d+t) _-Δ according to the outer dimension of the punch and the thickness of the material, where d is the diameter of the punch, and t is The material is thick. The value of Δ should be appropriate. If the value is too large, the sheet will be plastically thinned in the thickness direction, which will affect the wall thickness and size requirements of the workpiece; if the value is too small, the tightness will not be reliable. Generally, Δ=(1%~2%) t.

锥形抱紧件6外形构成的锥面角度设计时，要防止锥形推块5与锥形抱紧件6之间产生自锁，同时要考虑到竖直位移与水平位移之间及抱紧力与拉深力之间的关系。此处经过计算取28°～35°为宜。When designing the angle of the conical surface formed by the shape of the conical clamping member 6, it is necessary to prevent self-locking between the conical push block 5 and the conical clamping member 6, and at the same time take into account the vertical displacement and horizontal displacement and the tightness The relationship between force and deep drawing force. It is advisable to take 28°～35° after calculation here.

锥形推块5下设置有橡胶垫4，以提供足够大的抱紧力。通过在橡胶垫4下面放入不同厚度的垫板，可调节橡胶垫4的预压缩量，从而调节预抱紧力的大小。A rubber pad 4 is arranged under the tapered push block 5 to provide a large enough holding force. By putting backing plates of different thicknesses under the rubber pad 4, the pre-compression amount of the rubber pad 4 can be adjusted, thereby adjusting the size of the pre-clamping force.

顶杆15用于拉深结束后将工件从锥形抱紧件6及凹模7内顶出，其上细下粗并有锥面过渡，以便上模回程时使3个抱紧块能沿径向自动张开，为下次拉深做好准备。The ejector rod 15 is used to eject the workpiece from the conical clamping part 6 and the die 7 after the deep drawing is completed. Radial automatic opening, ready for the next deep drawing.

锥形抱紧件6必须有一定的深度，如果太浅，则由于未能有效的抱紧零件或者在较大抱紧力下使工件厚向产生塑性变形影响壁厚精度。深度太大时，相当于抱紧时刻推迟。一般最佳抱紧深度取(40％～45％)h，h为杯形件拉深后的高度。The tapered clamping member 6 must have a certain depth. If it is too shallow, the thickness of the workpiece will be plastically deformed due to failure to effectively clamp the part or under a large clamping force, which will affect the wall thickness accuracy. When the depth is too large, it is equivalent to delaying the holding time. Generally, the best holding depth is (40% to 45%) h, where h is the height of the cup-shaped part after deep drawing.

本发明在杯形件拉深过程中，主动施加外力控制金属流动趋势，延缓和阻止拉裂缺陷的产生，降低极限拉深系数，改善杯形件拉深壁厚的均匀性，可显著的提高杯形件拉深成形效率和质量。该新途径如果能应用于实践生产，节能省料，成本显著降低，能够实现金属塑性精确成形，提高生产效率和产品质量，增强企业的生产力和竞争力，应用前景广阔。In the drawing process of the cup-shaped part, the present invention actively applies external force to control the metal flow trend, delays and prevents the occurrence of drawing crack defects, reduces the limit drawing coefficient, improves the uniformity of the drawn wall thickness of the cup-shaped part, and can significantly improve Efficiency and quality in deep drawing of cup-shaped parts. If this new method can be applied to practical production, it will save energy and materials, significantly reduce costs, realize metal plastic and precise forming, improve production efficiency and product quality, and enhance the productivity and competitiveness of enterprises. It has broad application prospects.