Page 30 - Stanochny park

PROFESSIONAL ADVICE
of work and, ultimately, affects even
the wallet thickness of operators and
repairmen.
The benefits of using the
Kanban method were obvious to us!
If earlier all the tasks fell into one
dark boiler of the technical service
with at least a delay of one day, and
the inclusion of inconsistencies in the
work plan depended solely on the
charisma of the shift supervisor, now
transparency of the process was put
at the forefront.
Using this approach has created
an effective communication between
production and technical service. The
simplicity of the method ensured staff
involvement. Now the elimination of
discrepancies is carried out on the
basis of priority, taking into account
the availability of free human and
material resources - the principle
of drawing out and a continuous
flow of repairs, maintenance was
implemented. All identified problems
in the operation of the equipment are recorded, eliminated and visually accessible to any
employee of the enterprise. Spare parts supply planning has become an objective process, the
cost of purchasing unused spare parts, components and assemblies has been reduced.
Three months later, emergency downtime was significantly reduced, and the director
paved his way from parking to the office through this simple and intuitive visualization tool.
30 Stanochniy park
Discrepancies identified In the work of the technical Resolved Discrepancies
service Using CAE to Improve
TPM TPM TPM
card 3 card 2 card 1 Honing Efficiency
TPM
card 4 In the practice of leading
industrial enterprises, tools are widely
For example, after elimination of inconsistency used design automation. Modern
CAD -CAE -CAM systems allow you
No. 2, technical service specialists have the
opportunity to take on a new problem - inconsistency to organize an end-to-end production
process from the design development
No. 3. Each company employee can determine the stage to the release of the product.
overall dynamics at any time identification and CAEs are commonly used in design and are therefore more familiar to the designer. Meanwhile,
elimination of inconsistencies in production, as well the use of these tools for the analysis of the technological process opens up new possibilities
as the nature of malfunctions. for making effective decisions in technology. This article discusses the capabilities of CAE in
an application to the study of the process of forming the accuracy of shape and size when
honing the liner of an internal combustion engine and the errors arising from its heating and
Discrepancies identified In the work of the technical Resolved Discrepancies temperature deformations during processing.
service
TPM TPM
card 3 card 1
TPM TPM The geometric errors of the liner
card 4 card 2 are regulated by GOST R 53809-2010
and, depending on the type of engine
and the size of the liner, they are: for
Fig. 1. Stand and kanban cards.. the internal diameter of 0.03 ... 0.06
mm, for the profile of the longitudinal
section and the non-circularity of the
internal diameter, the tolerance is 0.01
... 0.012 mm. In the processing, it is
important to ensure the alignment
of the workpiece and the tool, the
absence of deformation of the thin-
walled workpiece during its fastening.
In this regard, honing is often used
fixing the sleeve in a rubber cuff for
mounting the sleeve over the hon.
D.V. Korotnev, trainer-consultant of GC Orgprom.
Clamping-releasing the workpiece is
performed by compressing the cuff
using air pressure.
Preliminary honing is performed
at high speeds and with a relatively
large allowance to correct errors in
the location and shape of the hole.
Significant efforts can lead to elastic
deformation of the workpiece. The final
honing, unlike most other machining
methods, is carried out at lower speeds,
which helps to reduce processing errors,
including those caused by thermal
deformation of the workpiece, but
reduces the productivity of the process.
The temperature of the workpiece
usually does not exceed 50 ... 100 °
C [1, 2, 3, 4], which, depending on its
size, can lead to a change in diameter
by 0.03 ... 0.05 mm.
The workpiece under the action
of a movable heat source, the role of
which is played by the honing process,
PROFESSIONAL ADVICE
heats up and changes its geometry, which leads
to a processing error. In this case, the size error is
proportional to the change in the temperature of the
workpiece, and the shape error is proportional to
the uneven heating of the workpiece. Modern CAE
systems - computer-aided engineering analysis tools
- allow you to analyze the occurring temperature
deformations in conditions of complex heating and
cooling of the object of study.
Considering that the processing time exceeds
the time of temperature stabilization [4, 5], the
process of heating the workpiece with a moving
source can be represented as the result of the action
of an equivalent distributed heat source, and consider
the problem in a stationary setting.
In accordance with [6], the work of honing
almost completely turns into heat. The circumferential
force Pok is proportional to the total area of the
working part of the honing bars Sbr and the specific
pressure of the bars ru: Pok = ρok ∙ Sbr ∙ pу.
The coefficient of proportionality pok in the first
approximation is taken equal to 0.4. The distribution
of heat between the workpiece, tool, chips, coolant
depends on the processing speed [7]. Part of the
amount of heat transferred to the workpiece for
speeds W = 40 ... 80 m / min is 0.4 ... 0.65. Thus, it
is possible to evaluate the heat (Q, W) entering the
workpiece using the expression:
Q = 0.4∙kзгW∙Sбр∙py, (1)
where kзг = 0,4…0,65.
The total amount of heat entering the
workpiece, calculated for different processing modes
[6] in accordance with (1), is shown in table 1.
We assume that the axial velocity of the hone
V varies according to a harmonic law, and we will
proceed from the assumption that the amount of
heat received by the elementary ring pad dF released
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