2.14. Conrod and group of piston
Removal
Withdraw a head of the cylinder block, a pendulum, the trundle bed of oil, the bomb of oil and a tube of branch of maslozaborny.
Withdraw the edge in the superior part of the cylinder formed as a consequence of the use.
If the sticks and the coverings of sticks are not marked, they mark them.
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Fig. 2.2. Piston and stick: 1 – ring of superior compression; 2 – lower the ring of compression; 3 – ring of scraper of oil; 4 – piston; 5 – piston finger; 6 – pierces; 7 – pin of fixation of a covering of a stick; 8 – stick of superior union; 9 – stick that is joined more low; 10 – stick covering; 11 – nut of fixation of a covering of a stick
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Put nuts of fixation out, discover the first stick and an insertion of load, mark insertions.
Put parts of a tube of rubber conrod pins not to damage a neck of an end of inclination and the wall of the cylinder in the moment of the removal of pistons joined with sticks.
Withdraw insertions of loads and take a stick from above of the block through a cylinder opening.
Withdraw in the same way other sticks and pistons.
To be demolished and pistons meeting with sticks
To be demolished and the pistons meeting with sticks is recommended 09234-33001 being executed through the device for motors with a volume of work of 1,1/1,3 l and the device 09234-3302 for motors with a volume of work of 1,5/1,6 l. The device of desmontagem and pistons meeting with sticks is shown in the fig. 2.3.
Check of technical condition
Pistons and fingers of piston
Check pistons to existence of zadir, scratches and other defects. Substitute incorrect pistons.
Check all the rings of piston to existence of chips, damages and I use strongly. Substitute incorrect rings. When it substitutes the piston also it substitutes a finger of piston.
One convinces of the lack of an excessive slit between a finger of piston and the pulls of the piston. Substitute the incorrect piston joined with a finger. The piston finger will enter lisamente in piston pulls pressing for a hand (in the room temperature).
Piston rings
Check a slit between rings of piston and the corresponding flutes of the piston. If the slit exceeds the very permissible value in the Repair, establish a new ring in a flute and again check a slit between a ring and a flute. If the slit exceeds the very permissible value again, substitute the piston and rings. If the slit does not exceed the very permissible value, only substitute rings of piston.
Nominal slit between a ring and a flute, mm:
ring of superior compression:
motor of 1,3 l..... 0.04-0.085
motor of 1,1 l..... 0,03-0,07
compression ring more low:
motor of 1,3 l..... 0.04-0.085
motor of 1,1 l..... 0,02-0,06
The very permissible slit of the top and the lowest compression rings it does 0,1 mm.
Since the check of a slit in the lock of a ring inserts a ring in the cylinder. Establish a ring in the right angle to a cylinder axle, when the piston held tight it lightly. Check a slit in the lock of a ring (it labels. 2.1) the probe. If the slit exceeds the very permissible value, the ring is subject to the substitution.
2.1 fixes
Split in the lock to cancel
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Name of a ring
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Split, mm
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nominal
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permissible maximum
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Ring of superior compression:
motor of 1,3 l
motor of 1,1 l
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0,20-0,35
0,15-0,30
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1,0
1,0
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Compression ring more low:
motor of 1,3 l
motor of 1,1 l
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0,37-0,52
0,30-0,50
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1,0
1,0
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Ring of scraper of oil
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0,20-0,70
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1,0
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Substituting rings without boring of cylinders the slit in the lock of a ring has to happen, when established a ring in the lowest thing, less part used the cylinder. The rings have to be substituted with rings of the same group dimensional.
You calculate the size of the groups of piston they touch a slit in the lock and his marking:
Nominal done not not marked
0,25 mm........... 25
0,50 mm........... 50
0,75 mm........... 75
1,0 mm............ 100
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TO OBSERVE
The marking puts itself in the superior surface of a ring of piston.
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Sticks
It does the installation of coverings of sticks according to the numbers of cylinders applied in coverings being demolished.
During the installation of a new stick it looks what adjusting the dredging of sticks are joined reassured from a side.
Always substitute sticks with the damage of one of the surfaces that are exposed to the axial load. Substitute sticks with the use in layers, and also in a strong roughness of a surface of work of an opening in the superior head of a stick.
Installation of rings of piston
The ring of scraper of oil is established by the first one. In the beginning establish a dilator in a flute, soon establish the rings of scraper of the lowest oil and superiors.
After the installation of all the elements of a ring of scraper of oil they check that the top and it will spin the lowest rings done freely, without jammings.
Establish the ring of compression more low for an etiquette.
Then establish the ring of superior compression.
The part with the rotation of the compression touches his locks as there is possible besides that one of other, looking what did not appear in an airplane with locks of discs of a ring of scraper of oil and a finger of piston.
Hold tight rings of piston through the adaptation and insert the piston in the cylinder.
During the installation of coverings of sticks it looks at the complaisance of numbers applied in sticks and his coverings being demolished. It is secured what the etiquettes in pistons and sticks during the installation (etiquettes of identification) saw towards an advanced part of the motor.
During the installation of new sticks it looks what will adjust the dredging of insertions it was installed from a side.
Useful data and advices
I use group tsilindroporshnevy
The motor of the car is compared sometimes with the heart of the person. Really, it works constantly while the car moves. Nevertheless, such a comparison is not exactly correct. The heart, as well as any lively organism, continuously autorepairs: in him constantly there are processes of languir of old cages and substitution his new, young person. What will not he say of the inanimate mechanism of any way – the motor motor. In spite of all our efforts, one wears away that it is almost irrevocable. Nevertheless the intensity of such a use, a motor resource before capital repairs, as well as durability of the whole car in general, in many aspects depends on this, I eat qualitatively if it does and if it makes working competently.
The main details of the motor – pistons with rings of piston, sticks and cylinders are specially subject to the use. Repair of pistons of the motor to most of prints. Moving repayable progressively between the top and the lowest dead points, they cover the enormous distance. In this way, in
the frequency of the rotation of the end of inclination 5.000 mines 1 and piston blow, they say, from 75 mm the total way surpassed by the piston inside a minute does 375 m. For the hour of the work of the motor this distance will make 2 km 250 m, e for a month of the Repair in 8 h in a day, except days off (that, naturally, it is unlikely for the middle car), the piston will surpass the 460 km distance. In the moment of the intensive Repair of the car during 5 years (to such knowledge duration of the Repair of the car before repairs of capital of the motor is confirmed for the statistic) the piston will cover the 24.000 km distance!
In this way, the use of the piston and the details (the cylinder of motor) inter-connected for him it is inevitable. Nevertheless the values of the use of the group of piston (pistons - piston rings) before repairs of capital of motors of several firms very strongly differentiate one of other. In this way, extreme use of pistons and rings of piston of driving Mercedes-Benz, Volkswagen, BMW, the majority the American and Japanese firms comes after the race approximately 300.000 km.
At the same time the motors of others, they say, of less perfect models, need the substitution of pistons and rings of piston after 50.000 km of a race (almost 10 times less).
What here do they reason in? And like the durability of these details does it depend on service conditions? For the answer to these questions we will consider two typical drawings of groups of piston of the motor of gasoline and the diesel. We are going to remember first of all what the gases pressure in cylinders of these motors in the beginning of the course of work differentiates approximately two times. In the gasoline motor – carburator or with the straight injection of the fuel it does 40-55 kg/cm2, in the diesel –
70-80 kg/cm2. Therefore, also, the oil pistons Diesel and diesel engines differentiate one of other though the main constructive decisions in them are identic.
The typical piston of the motor of gasoline is launched of the aluminum league and covered on the outside with a layer of tin of the extra improvement I make a profit to a cylinder mirror. The diameter of his superior part – head – is 0,1 mm less, of what the internal diameter of the cylinder. One does for the prevention of the interference of a head of the piston in the cylinder in the moment of a heating up to the work temperature. In you cancel flutes of the piston two rings of compression and a scraper of oil they are put. The lowest part of the piston – skirt – in oval angry section, and in height of conical form: in the superior part the diameter is less, of what in more low. Besides, in piston pulls with openings below a piston finger there is two steel insertions controlled by the temperature. All that is done for the prevention of the increase in the disagreement between a skirt and a mirror of the cylinder heating the piston. In the least thing, of which in aluminum, coefficient of the thermal expansion these insertions join a skirt in the direction, the perpendicular axes of the finger of piston.
The opening below a piston finger in modern motors moves normally of an axle of the symmetry of the piston to the right side of the motor. For the correct meeting of the piston with a stick and his installations in the motor cylinder on an opening of a pull there it is an etiquette that has to be turned towards an advanced part of the motor. Such a shift is done for the reduction of a component one of side of the force of pressure of gases that hold tight the piston to one of the parties of the cylinder during the work course.
The stick also has to be tackled correctly in the motor. In his supporting openings advanced to give of an oil current in the loaded party of a mirror of the cylinder (in some motors these openings go away) they happen. The insertions and a covering of the lowest head of a stick also if they supply with the corresponding etiquettes of the correct meeting. His new capacity of work and the durability significantly they depend on the exactness of the production of the piston and his right selection to a cylinder opening. The firms build the motor principals apply today the system according to which the pistons in the exterior diameter are broken normally in five or six classes with a 0,01 mm step. Except
this, they are divided in three or four categories with a 0,004 mm step according to the diameter of an opening below a piston finger. The motor cylinders also have the similar division in five classes. Such a system allows to catch more precisely the piston to someone, up to worn-out cylinder and a finger of piston of the necessary category – to an opening in pulls and to a stick. For the repairs of capital of motors that are composed normally in the boring one (I increase in diameters) of cylinders, the producers of spare pieces launch so called pistons of repair of the increased sizes.
The piston of the modern diesel is calculated according to the perception of higher pressures, therefore, the thickness of his bottom and pulls is more. Besides, the drawing of piston diesel is differentiated of a little considered in top. The main difference is the placing of the camera of combustion straightly in a head of piston. Since the combustion of the mixture of air of the fuel happens finding the piston near to the superior dead point, the hot gases heat a head of stronger piston, and the walls of the superior part of the cylinder are heated up lightly less, of what in gasoline motors. For the consolidation fiável from the piston in the cylinder in his extern surface five flutes of the installation of rings of piston are done. In three superior flutes the compression rings are established. In the lowest flutes two rings of scraper of oil are put. Many firms produce the rings of compression of the rectangular section almost not differently from rings of motors of gasoline. For more more progressive than, though more expensive, the drawing with a conical surface of superior work of a ring is. The angle of canvas that forms a cone in such rings is made 10 ° normally equal. The application of conical rings supplies some increase in his durability as during the work course the component of the force of pressure of gases in a conical surface of a ring besides that holds tight it to a cylinder mirror. The characteristic of the service and the repair of pistons with conical compression rings are the necessity of the right control of slits. The slits between a flute and rings of scraper of oil control the same thing as in gasoline motors.
The friction force between surfaces of a skirt of the piston and a mirror of the cylinder in the diesel are higher, of what in gasoline motors. Since the increase in the durability in a surface of a skirt of pistons put a layer of a special colloidal and covering of graphite. Much more improves a piston prirabatyvayemost to the cylinder and increases the term of his work before capital repairs. They scratch the similar processing of the surfaces of pistons it is applied today and in gasoline motors.
Except the use of surfaces of a skirt, also the flutes of rings of compression of pistons are worn away. Besides, also the flute of a ring of scraper of oil is worn away though such a use is normally great less. In the use of flutes of a ring of the piston they begin to move more and more intensively down and the height of a flute and more and more notable is one so a called action of bomb of rings. This action is shown in the more and more growing expense by the motor of oil of motor. Coming to the combustion camera, the oil is burned downstairs, forming the gray smoke that goes out a tube of leak of the car. In the considerable use of the substitution of flutes of rings in the new it improves a situation a little. There comes the objective necessity of the substitution of the whole group of piston, at the same time boring of cylinders to the repair size it is very desirable. All the described types of the use are natural and, unfortunately, an inevitable process.
However this natural use can be stretched on time, extending so the useful life of motor. The old material does not need of peddling here. Only it is necessary to carry out precisely demands of the producer of the Repair of the car, to use oil of qualitative motor and filters of oil, is correct to adjust the equipment of fuel. The good results are produced by the modifiers' use of high quality of oil and fuel, the medicine that modifies a microstructure of blankets of surfaces of the friction of motors.
Together with him the use of the motor, as well as the whole car in general, in many aspects it depends on the driver, on his qualification and technical literacy. Not for nothing the cars of the same mark in a drivers' service much time and lisamente, in others – are in the repair almost each week. The driver tried hardly ever allows the Repair of the motor with an overload and besides that with an explosion. Constantly listen like the motor of his car work, and immediately it resists any overload that is accompanied normally with a sound in growth of the low tone in the lowered frequency of the rotation of an end of inclination. Way of dispersal of the car also
it results from the increased use of the motor. Here the analogy with a horse and the rider appears: the careful owner without special necessity will not whip the canine friend, forcing running it immediately, especially when the horse still did not heat up. Naturally, in critical situations the driver is able to allow vistosamente, extremely agudamente to accelerate the car. But, if such an abrupt style of the driving becomes a habit, the repair of the motor is going to be supplied twice before, of what it is supplied by specifications.
Also other very often is watched, the type of the use that is not supplied by any education. Is it the break of emergence of elements shatunno? the group of piston and first of all it touches and the points of passage of the flutes to cancel of the piston. In gasoline motors one adheres first of all with an explosion. We are going to remember that the explosion is the combustion alike the explosion of the mixture of air of the fuel in the cylinder accompanied with the spasmodic increase in the pressure in the camera of combustion. To the punch equivalentemente sharp for a sled it goes on and on about the motionless piston and rings. The details, naturally, are not calculated according to such a load and can crack, when a cylinder mirror damaged then the splinters. The explosion reasons a little. For more main than of them – this Repair of the motor in the gasoline with more low, of what he is supplied by specifications, number of octano, and also to overheat and I work in the re-made rich mixture of gas. The experienced driver is obliged to hear blows of explosion during the Repair of the motor and to reduce immediately the provision of the fuel in the dispersal, and soon to withdraw the causes of explosion. A sound of an explosion is the metal clicks of the tone of high throw that coincides in the frequency with the frequency of the rotation of an end of inclination. Only they can be heard in the context of other sounds of the motor of work, specially in the lightly first ignition, and disappear in the reduction absolutely insignificant of the provision of the fuel (gas). Such an explosion only perceptible declares to the ignition correctly adjusted to the advanced coal, but it happens and so that the explosion blows appear at the same time when it are holding tight a pedal of gas pedal that, naturally, inadmissivelmente. To continue the movement in such a way it is equivalent to the dissection for the hammer of interiors of the motor.
The diesel engines are not so sensitive to the modification of the composition of the fuel, though in them there are preoccupations that lead to the increased use of details of the mechanism krivoshipno-conrod. It is first of all to overheat of the motor and the connected reduction of the viscosity of oil, specially if quality of low oil. The increased use can be also a consequence of the incorrect agreement of the bomb of fuel of high pressure and deterioration in the dispersal of the fuel in combustion cameras because of the violation of the work of mouths. And, naturally, many things depend on the driver.
In this way, of everything he said that it is possible to draw such conclusions. The durability of the motor of his car, as well as the whole vehicle in general, depends on two factors: the qualities of the production for which the firm of manufacture and the level of the technical Repair for which consequently the driver is a person in charge are responsible. It is necessary to be remembered of him both after the purchase of the car, and for preparation and drivers' training.