第1个回答 2009-03-12
Flow Through Conical Converging Dies
通过圆锥会聚模的流动
3.1. INTRODUCTION
3.1 引言
3.1.1 The Subject
3.1.1 主题
The study of metal flow through conical converging dies covers such processes as wire drawing,
open-die extrusion, hydrostatic extrusion, and extrusion through a confined chamber.
金属流过圆锥会聚模的研究包括像拉丝、开式冷挤压、静液挤压和通过约束腔的挤压之类的工艺。
Figure <1> represents a billet and die. 图1示出了一个毛坯和一个模具。The billet is made of an homogeneous isotropic material毛坯由一种均匀的各向同性材料制成； consideration will be given later to variable material properties.后面将对可变的材料性质给予考虑。 In the following simplification, the billet is a cylindrical rod of radius Ro; the rod is reduced to radius Rf by forcing it to pass through the conical converging die. 在以下的简化中，毛坯是一种半径为Ro的圆杆；该圆杆被迫通过圆锥会聚模而使半径缩小到Rf。Reduction is measured from the cross-section area of the billet at the entrance to the die (Ao) to that at the exit (Af). 半径的缩小通过模具入口处（Ao）到出口处（Af）的横截面积来衡量。
Three variables involved in the reduction process are noted at once:
在缩径过程中涉及的三个变量马上就被注意到了：
1. Reduction, which can be measured by the radius ratio Ro/Rf, the area ratio [(Ro / 2 2 Rf)], reduction in area: r = (Ao - Af) / Ao = 1 - Af / Ao = [1 - (Rf / Ro)], percent 2 reduction in area: r% = [1 - (Rf/Ro)]*100 or the effective or logarithmic strain: [Meff = 2*ln(Ro/Rf)]
1. 缩小量，它可以用半径比Ro/Rf；面积比[(Ro / 2 2 Rf)]；面积的缩小：r = (Ao - Af) / Ao = 1 - Af / Ao = [1 - (Rf / Ro)]；面积百分比2的缩小：r% = [1 - (Rf/Ro)]×100；或者有效应变或对数应变[Meff = 2*ln(Ro/Rf)]来衡量。
2. The Semi-cone Angle, ("), half the die angle; in wire drawing " is relatively small, possibly 6E to 12E; open- die extrusion may employ an " = 60E; for extrusion through a closed chamber, the die may be square, namely with " = 90E.
2. 在拉丝中的半锥角（“），即模具的半角相对较小，可能在6E到12E; 开式冷挤压可能采用 “ =60E; 对于通过闭合腔的挤压来说，模具可能是方的，即具有” =90E。
3. The third variable is friction between the die and the rod.
3. 第三个变量为模具和坯料杆之间的磨擦。本回答被提问者采纳
第2个回答 2020-06-15
3.2.
THE
EXPERIMENTAL
APPROACH
3.2
实验途径
3.2.1
The
Equipment
3.2.1
设备
A
drawbench
(Fig.
<2>)
may
be
used
to
measure
the
force
required
in
wire
drawing.
可以用一台冷拔机（图2）来测量拉丝所需的力。The
workpiece,
the
rod
passing
through
the
die,
has
its
front
end,
the
narrow
end,
held
by
grips.
把通过模具的工件（金属杆）的前端，即窄的一端，用夹具保持住。The
grips
are
pulled
by
a
hydraulic
system
-
a
cylinder
with
piston
-
or
by
other
means.
夹具由液压系统（一套带活塞的液压缸）或其他方法牵引。The
force
applied
is
transmitted
through
a
load
cell
(Fig.
<3>).
施加的力通过一个负荷传感器传递（图3）。In
a
load
cell
strain
gauges
are
applied
to
the
tensile
rod
to
produce
a
Wheatstone
bridge
in
which
the
voltage
differential,
properly
calibrated,
provides
a
measure
of
the
drawing
force.
For
details
see
Reference
[1].
在负荷传感器中，应变规被加到拉伸杆上，以产生一个惠斯登电桥，其中被很好定标的电压差动就提供了拉丝力的量度。关于详细情况，参见文献【1】。
2.2
Recording
of
the
Readings
2.2
读数的记录
The
measure
of
drawing
force
is
produced
continuously
on
a
recorder,
or
on
an
oscillograph
as
a
function
of
grip
displacement,
i.e.,
length
of
wire
drawn.
拉丝力的量度是作为夹具位移（即被拉金属丝的长度）的函数，在记录仪上或示波器上连续产生的。
Updated
instrumentation
may
digitize
the
force
vs.
displacement
readings
and
record
them
on
tape,
disk,
or
other
memory
unit
on
a
microcomputer.
现代化的仪器可以使力和位移关系的读数数字化，并将它们记录到磁带、硬盘或微机的其他存储装置上。Figure
<4>
represents
a
record
of
a
single
run
of
a
wire
through
a
die.
图4示出了金属丝单程通过模具的记录。With
the
application
of
motion
to
the
hydraulic
piston,
the
load
on
the
wire
rises;
the
steep
slope
of
the
curve,
due
to
the
elastic
stretching
of
the
system
with
increasing
force,
and
other
factors,
such
as
the
settling
of
the
ridges
of
the
grips
biting
into
the
workpiece,
occurs
before
any
wire
is
drawn
through
the
die.
随着向液压活塞施加运动，金属丝上的负荷就上升；在任何金属丝被拉丝通过模具之前就会发生以下现象，即曲线出现很陡的斜率，这是因为系统随着力的增加出现弹性伸长，以及其他因素的关系，这些因素包括夹具脊的固定咬入工件等。The
peak
of
the
curve
is
due
to
two
factors.
曲线的峰是由于两个因素。One
comprises
the
inertia
forces;
the
sudden
application
of
force
accelerates
the
wire
from
standstill
to
full
speed
in
a
short
time.
一个是惯性力；力的突然施加加快了金属丝在短时间内从静止到全速的速度。Another
cause
of
the
peak
is
that
at
standstill
and
slow
speeds,
friction
is
higher
than
friction
at
fully
developed
speeds.
曲线峰的另一个起因是，在静止和低速下的磨擦要高于全速前进速度下的磨擦。As
the
inertia
force
subsides
and
friction
reduces,
the
drawing
force
drops
to
its
steady-state
constant
value
for
the
constant
speed
drawing.
随着惯性力的下降和磨擦的降低，拉丝力降到其恒速拉丝时的稳态恒定值。This
measure
of
steady-
state
drawing
force
should
ordinarily
be
taken
as
the
force
reading.
稳态拉丝力的这一度量通常应被取作力的读数。When
the
drawing
force
is
divided
by
the
cross-section
area
of
the
wire
emerging
from
the
die,
the
result
is
the
drawing
stress
for
the
specific
combination
of
reduction,
cone
angle,
and
friction.
当拉丝力除以从模具中出来的金属丝的横截面时，其结果就是缩小量、锥角和磨擦特定组合下的拉丝应力。
第3个回答 2009-03-12
流经圆锥形聚合的模子
3.1. 介绍
3.1.1主题
金属的The研究流经圆锥形聚合的模子盖子这样过程象拔丝，
open-die挤压、流体静力的挤压和挤压通过一个局限的房间。
Figure代表宿营并且死。 宿营被做一同类的各向同性的
material; 考虑以后将被给予易变的有形资产。 在以下
simplification，宿营是半径Ro一把圆柱形标尺; 标尺减少到半径Rf被
forcing穿过的它圆锥形聚合死。 减少从被计量宿营的cross-section区域在入口的对模子(Ao)对那在出口(Af)。
在减少过程介入的Three可变物立即被注意：
1.减少，可以由半径比Ro/Rf测量，区域比率[(Ro/
2 2
Rf)]对区域的减少： r = (Ao - Af)/Ao = 1 - Af/Ao = [1 - (Rf/Ro)]百分之2
reduction在区域： r% = [1 - (Rf/Ro)]*100或有效或对数张力：
[Meff = 2*ln (Ro/Rf)]
2. 半锥体角度， (")，一半模子角度; 在拔丝”相对地是
small，可能对12E的6E; 开放死挤压也许使用“= 60E; 为
extrusion通过一个闭合的房间，模子也许是方形的，即与“= 90E。
3. 第三可变物是模子和标尺之间的摩擦
第4个回答 2009-03-12
圆锥收敛模具中的液流流动
3.1 简介
3.1.1 目的
关于圆锥收敛模具中金属液流流动的研究覆盖了诸如划线、开式挤压、静液挤压以及封闭腔挤压等工艺。
图1所示为一个钢坯及模具。钢坯由各向同性材料制成，不同材料的特性将在后面加以考虑分析。在下面的简化中，钢坯为一半径为Ro的圆柱型棒料，将该棒料压入圆锥收敛模具中，使其半径还原为Rf。减小值可以通过模具入口处及出口处钢坯的横截面予以测得。
三个与该还原过程相关的变量描述如下：
1. 减小量可通过半径比Ro/Rf、面积比Ro^2/Rf^2, 面积减小值：r= ... ..., 面积减小比: r%=..., 或有效/对数应变[ ... ]来测得。(公式我就不帮你翻译了，麻烦您自己抄一下吧)
2.半锥角， 划线过程中模具角的一半，相对较小，一般为6E-12E，开式挤压中可能达到20E, 对于封闭腔挤压，模具可能是方的，数值可能达到90E。
3.第三个变量为模具与棒料间的摩擦力。