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International Journal of Engineering & Technology, 7 (4.3) (2018) 135-139
International Journal of Engineering & Technology
Website: www.sciencepubco.com/index.php/IJET
Research paper
Driven Camshaft Power Mechanism of the Vehicle Diesel
Engine Fuel Pump
Mykola Мoroz
1
*, Serhii Korol
1
, Serhii Chernenko
1
, Yurii Boiko
1
, Oleksii Vasylkovskyi
2
1
Kremenchuk Mykhailo Ostohradskyi National University
2
Central Ukrainian National Technical University
*Corresponding author E-mail: mykolai.moroz@gmail.com
Abstract
The article deals with the actual problem associated with poor-quality operation of vehicle engines with incomplete loading and
operation at partial high-speed modes. It is shown that such engine operating modes make up the bulk of the time, especially when
the vehicle operates in urban conditions. Poor engine performance in these modes results in decline in fuel economy and
environmental performance. To improve the technical performance of diesel engines, a device is proposed that allows control the
uneven rotation of camshaft of vehicle diesel fuel pump. The kinematic schemes of the angular velocity transducers for fuel pump
camshaft power mechanism, the kinematic and power drive calculation method are developed.
Keywords: Camshaft, Diesel Engine, Fuel Pump, Kinematic Diagram, Partial Modes of Diesel Engine Operation.
1. Introduction
Modern automobile engines have a low workload while operating,
especially in urban conditions. Small loads and idling modes [1]
make up more than 50%. At the same time, fuel costs increase and
environmental indicators deteriorate. The problem of increasing
operational economic and environmental indicators is relevant.
The researches of passenger traffic flow carried out in works
[2,3,4] confirm incomplete loading of the vehicle engine in a city
mode operation. The operational fuel economy of a vehicle diesel
engine is determined by the economy of the partial load modes
conducted by the researches in [5,6,7].
In work [8] the basic principles of organization of driven uneven
rotation of vehicle four-cycle internal combustion engine camshaft
are described. According to this method, it is also possible to
organize driven uneven rotation of the camshaft of high pressure
fuel pump, which allows improve the fuel injection characteristics
at partial high-speed [9,10,11,12] diesel engine operation. This can
be achieved by stabilizing the linear speed of fuel pump plungers
regardless of crankshaft rotational rate of the vehicle diesel engine.
In the power transmission connecting the diesel engine crankshaft
to the pump camshaft, it is consistently proposed to install two
identical angular velocity transducers, which can be made in the
form of Hooke’s joints in this device. The advantages of this
choice of transducers include the fact that, firstly, these joints refer
to the traditional and well-studied elements of mechanical
transmissions produced in series. Secondly, one turnover of
Hooke's main shaft has not one (as for most other types of
transducers), but two periods of the output shaft angular velocity,
which facilitates the use of these transducers to drive camshafts
with a large number of cams. Thirdly, as it turned out as a result of
the kinematic analysis of the new drive, the law of angular
velocity variation provided by Hooke's joint proved to be very
successful for calculating the mechanism using two consecutively
operating angular velocity transducers. And, finally, fourthly,
when using these joints, the drive remains kinematically closed
and provides the calculated law of camshaft angular velocity
variation with the alternating nature of the transmitted torque.
However, this solution is applicable only to diesel engines with a
uniform alternation of fuel flares in the cylinders. Besides, it has,
as it was demonstrated by its detailed design, a significant
drawback: the longitudinal dimension (length) of the new
assembly exceeds the length of the automatic injection advancing
clutch, in the place of which it should be installed, from 2.5 to 3
times. Therefore, the proposed device can be used only in those
cases when the engine does not have a rigid restriction in the place
of fuel pump installation. In particular, such a drive can be
successfully used in the development of a motor bench with fuel
variable injection rate. The bench equipped with these transducers
and a device for manual adjustment of the degree of pump shaft
rotation unevenness will make it possible to obtain experimental
data on the dependence of the working process parameters on the
fuel injection intensity for each characteristic engine operation
mode, which in turn will improve the design of its fuel equipment.
The mentioned above increase in drive size is due to the fact that
Hooke's joint refers not to flat, but to spatial mechanisms.
Therefore, in this paper, it is proposed to use a kinematic analogue
of Hooke's joint as a transducer, which belongs to the class of
plane cam-and-lever mechanisms.
2. Related Work
In order to control uneven rotation of fuel pump camshaft on
diesel engine partial operating conditions, it is proposed to use a
cam-and-lever transducer of shaft rotation angular speeds in this
work. The principal kinematic diagram of cam-and-lever
mechanism is shown in Fig. 1.