CN104028647B

CN104028647B - Mushroom type rigid partitioning terrace die for bulging of thin-wall pipe fitting

Info

Publication number: CN104028647B
Application number: CN201410228711.4A
Authority: CN
Inventors: 余海燕; 王友
Original assignee: Tongji University
Current assignee: Tongji University
Priority date: 2014-05-27
Filing date: 2014-05-27
Publication date: 2017-01-11
Anticipated expiration: 2034-05-27
Also published as: CN104028647A

Abstract

A mushroom-shaped block punch for bulging of thin-walled pipe fittings, including an integrally formed umbrella-shaped part and a root, the axial length of the umbrella-shaped part and the root is consistent with the axial length of the tube blank, and the umbrella-shaped part is transverse A cylindrical structure with an arc-shaped cross-section, the radius of the arc is equal to the radius R of the thin-walled pipe, and the central angle corresponding to the arc is α, the root is a cylindrical structure with an isosceles trapezoidal cross-section, and the root is against the umbrella-shaped part The vertical plane setting of the block punch shown in the present invention is used to manufacture thin-walled pipe fittings, which can effectively prevent the parts from being easily broken at the punch gap during the forming process of the circular block punch and the mold gap on the surface of the part. The problem of indentation and edges and corners on the surface ensures the dimensional accuracy of the parts after forming; at the end of the forming state, the gap between the mushroom-shaped block punches is much smaller than the gap between the circular punches, which can effectively ensure the bulging parts. Dimensional accuracy and processing quality.

Description

Mushroom-shaped Rigid Segmented Punch for Bulging of Thin-walled Pipes

技术领域technical field

本发明属于机械设计领域，涉及乘用车零部件设计方法和塑性加工领域的模具设计，尤其是薄壁管件加工模具的设计。The invention belongs to the field of mechanical design, and relates to a design method of passenger car parts and a mold design in the field of plastic processing, especially the design of a thin-walled pipe fitting processing mold.

背景技术Background technique

薄壁管件具有中空、轻质等特点，在航空航天、核工业、建筑及汽车行业的应用越来越广泛。此外，与钣金件相比，管件具有刚度高、强度高以及抗冲击性能良好的特性，有利于减振降噪，因此在工业领域得到了广泛应用。Thin-walled pipe fittings have the characteristics of hollowness and light weight, and are more and more widely used in aerospace, nuclear industry, construction and automobile industries. In addition, compared with sheet metal parts, pipe fittings have the characteristics of high rigidity, high strength and good impact resistance, which is beneficial to vibration and noise reduction, so they have been widely used in the industrial field.

目前国内外的薄壁管件成形方法主要有液压胀形和刚性分块凸模胀形。液压胀形基本原理是：首先在管件内部引入液态介质如水或油，然后对液态介质施加压力，通过液态介质的压力传递使管坯成形为所需零件形状。液压胀形发展相对成熟，但是会涉及到高压的提供、高压下的密封以及高压下液体泄漏防范等问题，使液压成形设备及模具开发成本非常高，适合于大批量零件的制造。另一种成本相对较低的管件胀形方法是采用刚性分块凸模胀形，该方法基本原理是：模具由若干扇形块组成，在成形过程中各分块模具可在压机滑块作用下沿径向运动，带动管坯贴近凹模内壁使零件成形。由于初始状态模具直径小于胀形终了状态模具直径，因而在终了状态时分块模具间存在一定的间隙，这个间隙使零件内外壁产生一些压痕或棱边，严重影响零件的尺寸精度和使用功能。而且，胀形终了状态时模具间隙处管坯处于双向拉伸状态，导致此处易出现破裂等缺陷。为此，研究设计了一种呈蘑菇型的分块模具用于实现薄壁管件的高精度胀形。At present, the forming methods of thin-walled pipe fittings at home and abroad mainly include hydraulic bulging and rigid block punch bulging. The basic principle of hydraulic bulging is: first introduce a liquid medium such as water or oil inside the pipe fitting, then apply pressure to the liquid medium, and the tube blank is formed into the desired part shape through the pressure transmission of the liquid medium. The development of hydraulic bulging is relatively mature, but it will involve the supply of high pressure, the sealing under high pressure, and the prevention of liquid leakage under high pressure, which makes the development cost of hydroforming equipment and molds very high, and is suitable for the manufacture of large-scale parts. Another relatively low-cost bulging method for pipe fittings is to use rigid block punches for bulging. The basic principle of this method is: the mold is composed of several sector blocks, and each block mold can act on the slider of the press during the forming process. The bottom moves radially to drive the tube blank close to the inner wall of the die to form the part. Since the diameter of the mold in the initial state is smaller than the diameter of the mold in the final state of bulging, there is a certain gap between the block molds in the final state. This gap causes some indentations or edges on the inner and outer walls of the part, which seriously affects the dimensional accuracy and use function of the part. Moreover, when the bulge is finished, the tube blank at the mold gap is in a biaxially stretched state, which makes it prone to defects such as cracks. For this reason, a mushroom-shaped block mold was designed to realize high-precision bulging of thin-walled pipe fittings.

发明内容Contents of the invention

本发明提供了一种新型的蘑菇型分块凸模，其避免了目前国内外采用液压胀形工艺中存在的零件尺寸精度不良和圆环形分块凸模胀形中模具间隙导致的零件尺寸精度不良及在间隙处易破裂等问题，可实现薄壁管件的高精度胀形。The invention provides a new type of mushroom-shaped block punch, which avoids the poor dimensional accuracy of the parts in the hydraulic bulging process at home and abroad and the part size caused by the mold gap in the ring-shaped block punch bulge. Problems such as poor precision and easy cracking in the gap can realize high-precision bulging of thin-walled pipe fittings.

为达到上述目的，本发明的解决方案是：To achieve the above object, the solution of the present invention is:

一种用于薄壁管件胀形的蘑菇型分块凸模，包括一体成型的伞状部和根部，所述伞状部和所述根部轴向平齐设置，且所述伞状部和所述根部的轴向长度与薄壁管件的轴向长度一致：A mushroom-shaped segmented punch for bulging of thin-walled pipe fittings, comprising an integrally formed umbrella-shaped part and a root, the umbrella-shaped part and the root are axially aligned, and the umbrella-shaped part and the root The axial length of the root is consistent with the axial length of thin-walled pipe fittings:

所述伞状部是横截面为弧形的柱体结构，所述弧形的半径与所述薄壁管件半径R相等，且弧形对应的圆心角为α；The umbrella-shaped portion is a cylindrical structure with an arc-shaped cross section, the radius of the arc is equal to the radius R of the thin-walled pipe, and the central angle corresponding to the arc is α;

所述根部是横截面为等腰梯形的柱体结构，所述根部抵靠所述伞状部的竖向平面设置.所述等腰梯形上底边一端点距离同侧所述弧形端点的距离l₁的大小为：The root is a cylindrical structure with an isosceles trapezoidal cross section, and the root is set against the vertical plane of the umbrella-shaped part. The size of the distance l ₁ is:

${l l}_{11} = = R R \cdot \cdot \frac{s the s i i n no \frac{α α}{22}}{c c o o s the s β β} - - ((R R \cdot &Center Dot; c c o o s the s \frac{α α}{22} - - R R \cdot \cdot s the s i i n no \frac{α α}{22} \cdot \cdot t t a a n no β β - - h h - - d d)) \cdot \cdot t t a a n no \frac{α α}{22} + + h h \cdot &Center Dot; \frac{c c o o s the s ((β β - - α α))}{s the s i i n no α α};;$

所述等腰梯形的下底边处两底角的角度与所述弧形对应的圆心角相同，均为α；The angles of the two base angles at the lower base of the isosceles trapezoid are the same as the central angle corresponding to the arc, both are α;

所述等腰梯形下底边的长度l₂的大小为：The size of the length _l of the lower base of the isosceles trapezoid is:

${l l}_{22} = = 22 \cdot &Center Dot; sin sin \frac{α α}{22} \cdot &Center Dot; ((R R \cdot &Center Dot; cos cos \frac{α α}{22} - - R R \cdot &Center Dot; sin sin \frac{α α}{22} \cdot &Center Dot; tan the tan β β - - h h - - d d)) \cdot &Center Dot; ((\frac{sin sin ((\frac{α α}{22} - - β β))}{cot cot \frac{α α}{22}} + + cos cos ((\frac{α α}{22} - - β β))));;$

其中，n为分块凸模的块数，0<d<1/4R，h为分块凸模根部高度，d为分块凸模沿径向平移距离。in, n is the number of blocks of the block punch, 0<d<1/4R, h is the root height of the block punch, and d is the radial translation distance of the block punch.

优选的，所述分块凸模的块数n为偶数。Preferably, the block number n of the block punch is an even number.

优选的，所述凸模制作材料的硬度高于薄壁管件材料的硬度。Preferably, the hardness of the material for making the punch is higher than that of the thin-walled pipe material.

本发明的有益效果是：采用本发明所示的分块凸模实现胀形，在成形过程中可有效避免圆形分块凸模成形过程中零件在模具间隙处容易破裂以及模具间隙在零件表面上产生压痕、棱角的问题，保证零件成形之后的尺寸精度；在成形终了状态时本发明所示分块凸模之间的间隙远比圆形凸模的间隙小，能有效保证胀形零件的尺寸精度和加工质量。The beneficial effects of the present invention are: adopting the segmented punch shown in the present invention to realize bulging can effectively avoid the parts being easily broken at the mold gap during the forming process of the circular segmented punch and the gap between the molds on the surface of the part. The problem of indentation and edges and corners on the surface ensures the dimensional accuracy of the parts after forming; at the end of the forming state, the gap between the block punches shown in the present invention is much smaller than the gap between the circular punches, which can effectively ensure the bulging parts Dimensional accuracy and processing quality.

且分块凸模的尺寸与数量可根据实际需要进行调整，可以适应不同几何尺寸的管件，具有良好的适应性。Moreover, the size and quantity of the block punches can be adjusted according to actual needs, and can adapt to pipe fittings of different geometric sizes, with good adaptability.

附图说明Description of drawings

图1是本发明分块凸模一实施例的结构示意图；Fig. 1 is the structural representation of an embodiment of block punch of the present invention;

图2-1是目标管件轮廓分块示意图；Figure 2-1 is a block diagram of the outline of the target pipe fitting;

图2-2每段圆弧平移示意图；Figure 2-2 Schematic diagram of translation of each arc;

图2-3最终几何外形确定示意图；Figure 2-3 Schematic diagram of final geometric shape determination;

图3-1本发明的凸模结构胀形过程示意图中胀形前分块凸模缩聚状态；Fig. 3-1 The polycondensation state of the block punch before bulging in the schematic diagram of the bulging process of the punch structure of the present invention;

图3-2胀形过程中分块凸模状态；Figure 3-2 The state of the block punch during the bulging process;

图3-3胀形终了时分块凸模状态。Figure 3-3 The state of the block punch at the end of bulging.

具体实施方式detailed description

以下结合附图对本发明的实施作进一步的说明。The implementation of the present invention will be further described below in conjunction with the accompanying drawings.

如图1所示，本发明公开了一种用于薄壁管件胀形的蘑菇型分块凸模，其包括伞状部10和根部20，伞状部10与根部20上下面平齐设置，二者通过机械加工方式一体成型，且伞状部10和根部20的轴向长度与薄壁管件的轴向长度一致。其中，伞状部10是横截面为弧形的柱体结构，弧形的半径与薄壁管件半径R相等，且弧形对应的圆心角为α，根部20是横截面为等腰梯形的柱体结构，其毗邻伞状部的竖直平面设置，等腰梯形上底边一端点距离同侧弧形端点的距离 As shown in Figure 1, the present invention discloses a mushroom-shaped block punch for bulging of thin-walled pipes, which includes an umbrella-shaped part 10 and a root part 20, and the upper and lower sides of the umbrella-shaped part 10 and the root part 20 are flush with each other. The two are integrally formed by machining, and the axial length of the umbrella-shaped part 10 and the root part 20 is consistent with that of the thin-walled pipe. Among them, the umbrella-shaped part 10 is a cylindrical structure with an arc-shaped cross section, the radius of the arc is equal to the radius R of the thin-walled pipe, and the central angle corresponding to the arc is α, and the root 20 is a column with an isosceles trapezoidal cross-section Body structure, which is adjacent to the vertical plane of the umbrella-shaped part, the distance between the end point of the upper base of the isosceles trapezoid and the arc end point of the same side

等腰梯形下底边的长度l₂的大小为：The size of the length l ₂ of the bottom of the isosceles trapezoid is:

其中，n为分块凸模的块数，0<d<1/4R，h为分块凸模根部高度，d为分块凸模沿径向平移距离。d和h是根据经验得出来的范围，可以灵活选取范围。d的取值范围依据凸模推送机构确定，本实施例中，0<d<1/4R，机构与凸模接触面宽度越大则d值越小，反之d值越大；h根据凸模推动机构确定，机构与凸模的接触面宽度大，则h取值相应越小，反之h取值越大，本实施例中，h的具体大小取值可根据梯形高度的计算公式推算。in, n is the number of blocks of the block punch, 0<d<1/4R, h is the root height of the block punch, and d is the radial translation distance of the block punch. d and h are ranges obtained based on experience, and the ranges can be selected flexibly. The value range of d is determined according to the pushing mechanism of the punch. In this embodiment, 0<d<1/4R, the larger the width of the contact surface between the mechanism and the punch, the smaller the value of d, otherwise the larger the value of d; The pushing mechanism is determined. If the width of the contact surface between the mechanism and the punch is large, the value of h will be smaller accordingly. Otherwise, the value of h will be larger. In this embodiment, the specific value of h can be calculated according to the calculation formula of the trapezoidal height.

本发明所示的用于薄壁管件胀形的分块凸模的具体尺寸确定方法如图2-1至2-3所示。The specific size determination method of the segmented punch for bulging thin-walled pipe fittings shown in the present invention is shown in Figures 2-1 to 2-3.

(1)如图2-1所示，首先根据目标管件(即薄壁管件)尺寸将其轮廓分割成偶数块n，对分割出来的每一块圆弧沿顺时针方向选取一个原点，然后将每个圆弧绕端点逆时针旋转角度β，其中β根据分块凸模的个数确定 (1) As shown in Figure 2-1, first divide the outline of the target pipe (that is, thin-walled pipe) into even blocks n according to the size of the target pipe, select an origin point clockwise for each segmented arc, and then divide each An arc rotates counterclockwise around the end point by an angle β, where β is determined according to the number of block punches

(2)如图2-2-所示，分别将每个旋转之后的圆弧沿径向平移距离d，所示其中d的取值范围是0<d<1/4R；(2) As shown in Figure 2-2-, respectively translate the circular arc after each rotation by a distance d in the radial direction, where the value range of d is 0<d<1/4R;

(3)如图2-3所示，作出每个圆弧的弦，在将其沿径向向内平移距离h。删除几何干涉部分最终就能得到凸模的几何外形，如下图2-3所示。(3) As shown in Figure 2-3, draw the chord of each arc, and then translate it radially inward for a distance h. By deleting the geometric interference part, the geometric shape of the punch can be finally obtained, as shown in Figure 2-3 below.

本发明所示的用于薄壁管件胀形的分块凸模的具体工作过程如图3-1至图3-3所示。The specific working process of the segmented punch for bulging thin-walled pipe fittings shown in the present invention is shown in Figure 3-1 to Figure 3-3.

(1)根据薄壁管件几何形状和管坯材料特性确定分块凸模的个数n和尺寸并进行加工，凸模材料根据管坯材料确定，确保硬度比管坯材料高，无其他特殊限制，本实施例中，如图3-1所示，分别包括6块蘑菇状分块凸模、整体式凹模，以及凸模与凹模之间的管坯(即薄壁管件)；(1) Determine the number n and size of the block punch according to the geometric shape of the thin-walled pipe fitting and the material properties of the tube blank and process it. The punch material is determined according to the tube blank material to ensure that the hardness is higher than that of the tube blank material, and there are no other special restrictions , in the present embodiment, as shown in Figure 3-1, respectively comprise 6 pieces of mushroom-shaped segmented punches, integral dies, and tube blanks (i.e. thin-walled pipe fittings) between the punches and dies;

(2)加工前凸模缩聚在一起，在胀形前，各分块凸模缩聚在一起，此时各分块凸模根部20相互接触形成一个与管坯同轴的圆弧面；(2) The punches are condensed together before processing, and before bulging, each block punch is condensed together, and at this time, the roots 20 of each block punch are in contact with each other to form an arc surface coaxial with the tube blank;

(3)加工过程中凸模沿径向运动，管件胀形过程中，各分块凸模首先沿径向运动；(3) During the processing process, the punch moves radially, and during the bulging process of the pipe fittings, the punches of each block first move along the radial direction;

(4)管坯接触后再做旋转运动直至凸模的外轮廓与管坯内壁完全接触实现胀形，当分块凸模的伞状部10的弧形面上的各点与管坯接触后再做旋转运动，直至分块凸模的外轮廓面与管坯内壁完全接触实现胀形。(4) After the tube blank is in contact, do a rotating motion until the outer contour of the punch is in full contact with the inner wall of the tube blank to realize bulging. Make a rotating movement until the outer contour surface of the block punch is in full contact with the inner wall of the tube blank to realize bulging.

本发明所示的薄壁管件胀形的分块凸模根据目标薄壁管件轴对称的特点，将管坯内壁胀形凸模分成偶数块以确保在胀形过程中每块凸模能均匀受力，蘑菇凸模的形状见附图1。凸模参数包括凸模分块个数n、分块凸模根部横截面的尺寸l₂、分块凸模根部高度(等腰梯形的高度)h、分块凸模蘑菇伞状部圆弧半径R。在成形终了状态时蘑菇凸模之间的间隙远比圆形凸模的间隙小，能有效保证胀形零件的尺寸精度和加工质量。在成形过程中可有效避免圆形分块凸模成形过程中零件在凸模间隙处容易破裂以及模具间隙在零件表面上产生压痕、棱角的问题，保证零件成形之后的尺寸精度。且根据管坯初始直径可以确定凸模的根部尺寸(等腰梯形的下底边长度)l₂，凸模的伞状部尺寸等于管件胀形区尺寸除以凸模分块个数，可根据零件几何尺寸对凸模分块数目进行调整，每个分块凸模的尺寸也可以调节。在胀形过程中，各分块凸模首先以管坯中心轴为中心进行径向进给运动，当分块凸模顶端与管坯内壁接触后再做旋转运动实现管件的最终成形，可以适应不同几何尺寸的管件，保证有良好的适应性According to the axisymmetric characteristics of the target thin-walled pipe fittings, the bulging punch of the thin-walled pipe fitting shown in the present invention divides the bulging punch of the inner wall of the tube blank into even blocks to ensure that each punch can be evenly affected during the bulging process. Force, the shape of the mushroom punch is shown in Figure 1. The punch parameters include the number of punch blocks n, the size of the cross-section of the root of the block punch l ₂ , the height of the root of the block punch (the height of the isosceles trapezoid) h, and the radius of the mushroom umbrella of the block punch R. At the end of the forming state, the gap between the mushroom punches is much smaller than that of the circular punches, which can effectively ensure the dimensional accuracy and processing quality of the bulging parts. In the forming process, it can effectively avoid the problems that the parts are easy to break at the gap of the punch during the forming process of the circular block punch, and the problems that the die gap produces indentations and edges on the surface of the part, ensuring the dimensional accuracy of the part after forming. And the root size of the punch (the length of the lower base of the isosceles trapezoid) l ₂ can be determined according to the initial diameter of the tube blank. The geometric dimensions of the part adjust the number of punch blocks, and the size of each block punch can also be adjusted. During the bulging process, each block punch first performs radial feed movement centered on the central axis of the tube blank. When the top of the block punch contacts the inner wall of the tube blank, it then rotates to achieve the final forming of the tube, which can adapt to different Fittings with geometric dimensions to ensure good adaptability

上述的对实施例的描述是为便于该技术领域的普通技术人员能理解和使用本发明。熟悉本领域技术的人员显然可以容易地对这些实施例做出各种修改，并把在此说明的一般原理应用到其他实施例中而不必经过创造性的劳动。因此，本发明不限于上述实施例，本领域技术人员根据本发明的揭示，不脱离本发明范畴所做出的改进和修改都应该在本发明的保护范围之内。The above description of the embodiments is for those of ordinary skill in the art to understand and use the present invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative effort. Therefore, the present invention is not limited to the above-mentioned embodiments. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims

1. The utility model provides a mushroom type partitioning terrace die for thin wall pipe bulging which characterized in that: umbrella portion and root including integrated into one piece, umbrella portion with root axial parallel and level sets up, just umbrella portion with the axial length of root is unanimous with thin-walled tube's axial length:

the umbrella-shaped part is of a cylinder structure with an arc-shaped cross section, the radius of the arc is equal to the radius R of the thin-wall pipe fitting, and the central angle corresponding to the arc is alpha;

the root part is of a cylinder structure with an isosceles trapezoid cross section and is arranged against the vertical plane of the umbrella-shaped part;

the distance l between one end point of the upper bottom edge of the isosceles trapezoid and the arc end point on the same side₁The size of (A) is as follows:

l_{1} = R \cdot \frac{s i n \frac{α}{2}}{c o s β} - (R \cdot c o s \frac{α}{2} - R \cdot s i n \frac{α}{2} \cdot t a n β - h - d) \cdot t a n \frac{α}{2} + h \cdot \frac{c o s (β - α)}{s i n α};

the angles of two bottom angles at the lower bottom edge of the isosceles trapezoid are the same as the central angles corresponding to the arcs and are both alpha;

wherein,n is the number of the block male dies,0<d<1/4R, h is the height of the root of the block terrace die, d is the translation distance of the block terrace die along the radial direction.

2. The segmented punch as claimed in claim 1, wherein: length l of lower base edge of isosceles trapezoid₂The size of (A) is as follows:

l_{2} = 2 \cdot s i n \frac{α}{2} \cdot (R \cdot c o s \frac{α}{2} - R \cdot s i n \frac{α}{2} \cdot t a n β - h - d) \cdot (\frac{s i n (\frac{α}{2} - β)}{\cot \frac{α}{2}} + c o s (\frac{α}{2} - β));

3. The segmented punch as claimed in claim 1, wherein: the number n of the blocking male dies is an even number.

4. The segmented punch as claimed in claim 1, wherein: the hardness of the male die manufacturing material is higher than that of the thin-wall pipe fitting material.