Antipyretics for children are prescribed by a pediatrician. But there are emergency situations with fever when the child needs to be given medicine immediately. Then the parents take responsibility and use antipyretic drugs. What is allowed to be given to infants? How can you lower the temperature in older children? What medications are the safest?

How to make a rocker, my mentor, a man already of advanced age, told me (all the younger ones were at the front). Not without reason, he had a reputation for being a good judge in many matters, but one might say that he had no idea about the different radii and millimeters and determined all the dimensions strictly “by eye.” According to the authoritative opinion of an experienced master a good rocker should be durable and at the same time as light and springy as possible. The buckets should be located as far as possible from the water carrier’s body, but still in such a way that he can reach the handles of the buckets and hold them with his hands, preventing the buckets from swinging and splashing water when walking. In addition, when hooking buckets of water standing on the ground with a rocker, a person should not bend down too much to hook the rocker onto his shoulders. These are the qualities of the rocker, from the point of view of the old master, that should determine the optimal dimensions of this simple, centuries-tested device for carrying water.

So, let's start making the rocker arm

To do this, we will select a suitable raw birch with a diameter of at least 80 mm and a length of approximately 1.5 m. We will not remove the birch bark (my mentor claimed that it holds water well), we will use an ax to give the workpiece a rough rocker shape with a margin for deformation during drying (see. Fig. 1). In this case it should Special attention pay attention to the place of the bend - you need to make sure that it is of the same thickness along the entire length and does not have knots or cracks. Sometimes small cuts 2-3 mm deep are made at regular intervals on the inside of the future bend of the rocker arm.

(a is the starting size).

At the ends of the rocker blank opposite to the cuts, small notches are made for twine, with the help of which the ends of the blank are pulled together, bending the future rocker. Before bending the rocker, the ends of the workpiece must be immersed in boiling water for 5-10 minutes, so that later, when drying, the wood does not crack in these places - this is how the master explained. Next, the bend of the rocker arm is soaked in water, thoroughly steamed over a fire and, using a string and a stop, bent to the desired radius, making sure that the curvature of the bend of the rocker arm is smooth and uniform. Having reached the desired position, fix the rocker arm in the bent state of the towline. After drying the workpiece, use a sharp ax and a plane to bring the rocker to the required size (see Fig. 2).

At the ends of the rocker, recesses are made into which buckets are hooked. Later, instead of recesses, they began to use metal hooks attached to the ends of the rocker. Typically, these hooks for hooking buckets are made from 4-6 mm steel wire. The shape and dimensions of the hooks are shown in Fig. 3.

To attach the hook, a small groove is cut out at the end of the rocker, the hook is driven into a pre-drilled hole and, just in case, the hook is secured with a bracket (Fig. 2). That's all - the rocker is ready!

A rocker for catching bream (bream) is a fairly common tackle. Each fisherman makes such a device in his own way. I offer you my version, which has already been tested on winter fishing.

To make it you will need:

Line 0.12 mm (can also use 14 mm)
Sinker “olive” 10 g.
Two hooks No. 12
Two beads as a stopper
Pen refill
Drill
Two drills with a diameter of 3 and 6 mm.

Stages of work on making a rocker for winter fishing:

I blow the paste out of the rod. The paste remaining on the inner walls of the rod can be washed with water. I cut the rod into three parts: 5 cm, 5 cm and 3 cm.

I drill a hole along the length in the olive sinker with a 3 mm drill. I use a regular household drill. I do the same for the width.

On one side of the sinker, I increase the diameter of the hole to 6 mm by about 2/3 of the width. This is done for the convenience of tying the fishing line.

I insert 5 mm pieces of the rod into the holes in the sinker on both sides. They fit very tightly, which is good for the strength of the entire structure. We insert part of the 3 mm rod into the hole in the sinker from above. The base of the rocker arm is ready.

Some fishermen prefer a float when fishing using a rocker arm. Personally, I don’t like it because it only works on the rise. The nod works both for raising and lowering. The float freezes in the hole, so for the lazy I recommend using a nod.

A rocker of this design allows the fisherman to immediately feel a bite, even the weakest one. Unlike a static rocker, where the leads do not have free passage through the tubes, this device makes it possible to hook in time and not miss the prey. Suitable not only for catching bream, but also other bottom fish.

The width of the rocker arm is about 11 cm, suitable for fishermen with the appropriate drill diameter. I have 130 mm. The length of the rocker arm can be reduced to the required size.

Alexey Shevnin, Kirov region, Sovetsk -Especially for

ROCKER ARM (ROCKER ARM) - a device for carrying buckets, buckets, baskets.

The yoke (yoke) used to be considered the primary item of rural life. Now you can hardly see a rocker anywhere, except perhaps in the distant outback, in those villages and hamlets where national customs are still alive, where traditional crafts and crafts are still preserved.

It was made from linden, aspen, and willow, the wood of which is light, flexible, and resilient.

In the everyday life of Russian peasants, rocker arms of various shapes were known. The most widespread are bent rocker arms. They were bent from steamed wood in the shape of an arc. A rocker of this type fit comfortably on the shoulders of a woman who held it with her hands. Buckets, placed on the ends of the beam in specially cut grooves for this purpose, hardly swayed when walking.

In the Bryansk region, with the help of a rocker, they carried water into the house for drinking and to water livestock, they dragged laundry to the river to rinse, wash cucumbers, etc. The yoke helped to carry two buckets of water on one’s shoulders for several hundred meters without getting tired, shifting the yoke from one shoulder to the other while moving. And how pleasant the taste is of water from the well, and even from that bucket that my own mother brought on a rocker. You used to run around like a baby, run ahead of your mother, drink water straight from the bucket - and the fatigue would go away somewhere, and new strength would seem to flow in.

Carrying water on a rocker is a whole ritual. When you go for water, two empty buckets should be in your left hand, and the rocker itself should be in your right. And, of course, conversations at the well. It happens that women can talk for tens of minutes while holding a yoke with full buckets on their shoulders. This is truly a woman’s passion for conversations, behind which they don’t even notice the heaviness.

At the well, the bucket is hooked onto a rocker, first to the back, then to the front.

The main thing when carrying water in this way is to maintain balance.

You can immediately throw a rocker with buckets on your shoulder. We assure you, it is not as difficult as it seems at first glance. You also need to be able to scoop up water with a bucket on the rocker.

Sometimes it happens that a clumsy person's bucket will fly off the hook of the rocker directly into the well. Then dig in and get it out. You will also get a scolding from your neighbors. At Russian weddings, the bride on her wedding day must bring buckets of water on a yoke decorated with ribbons, without spilling a single drop.

In the everyday life of Russian peasants, rocker arms of various shapes were known. During excavations in Veliky Novgorod in layers of the XI - XIV centuries. archaeologists have found a large number of arched rocker arms. They were the most widespread. They were bent from steamed wood in the shape of an arc. A rocker of this type fit comfortably on the shoulders of a woman who held it with her hands. Buckets, placed on the ends of the beam in specially cut grooves for this purpose, hardly swayed when walking.

In many villages there were also rocker arms cut from a wide and durable board. The straight board tapered at the ends, and in the middle there was a notch for the woman’s neck. Buckets of water were secured to long hooks that descended from the ends of the beam.

A rocker in the form of a round stick, well known in Western Europe, was rarely seen among the Russians. It was uncomfortable to use, as the stick put a lot of pressure on the shoulders. With its help, Russian peasant women most often carried washed clothes from the river. At the same time, the yoke was carried by two women: one end of it lay on the shoulder of the peasant woman walking in front, the other on the shoulder of the one walking behind.

There are many riddles and proverbs about rocker arms with buckets:

“Two brothers want to fight, but their arms are short,”

"Two are bathing, and the third is marveling"

“Between two seas, over mountains of meat, a bent bridge lies.”

“A woman’s mind is like a woman’s yoke: it’s askew, and crooked, and at two ends.”

“Craft is not a rocker, it won’t weigh on your shoulders.”

“Dust in a column, smoke in a rocker - either from melancholy, or from dancing!”

The rocker (or, as they used to say in the old days, the rocker) was first found in monuments of the 16th century. “A single water carrier, a bow lever used to carry a pair of buckets on the shoulder” soon becomes popular in the most remote corners of Russia. Its merits were deservedly appreciated in ancient cities, but especially in villages. Indeed, in winter it is possible to walk along a narrow, deep path without a rocker only with great difficulty, since the buckets will touch the snowdrifts. In the summer, dust, seeds of ripened grasses and numerous insects hiding in the grasses constantly fall into the buckets that are carried in the hands. But most importantly, carrying buckets on a rocker is much easier. Even the gait becomes light and graceful when the buckets, like birds, soar over the snowdrifts or tall grass. And involuntarily a riddle was born among the people: “Are there two ticks sitting on a stick?” This is about buckets with a rocker arm.

Three types of rocker arms were known in Rus': stick-shaped, bent and carved. The first was a straight round stick with small hooks at the ends. Sometimes not only buckets, but also washed clothes were carried on such rockers. This, apparently, was the most ancient and not very convenient rocker.

Then they figured out how to attach hooks to it, and it became more convenient, since it became possible to hold the buckets with your hands. But the stick still put a lot of pressure on the shoulders, so instead they began to use a rocker cut from a fairly wide and strong board. It tapered towards the edges, and in the middle, in the wide part, a special semicircular cutout was made for the neck. Wooden or metal hooks were attached to the ends of the beam, from which buckets were hung.

Rice. 1 History of the rocker arm in pictures

This type of rocker still exists in a number of areas today. But nevertheless, the bent rocker arm has become more widespread. It is in every rural house where residents use wells.

In the old days, craftsmen who knew how to make light, comfortable and beautiful rocker arms were in every area. The products of the talented craftsman had their own style, and they were easily distinguished by their shape and decorative finish. Sometimes the bucket cooper himself made the rocker arms complete with buckets. In late autumn or early spring, when wood is especially flexible, the craftsman went into the forest to get raw materials.

The wood used for the rocker arms must be light, strong and flexible, as well as uniform and resistant to cracking. These requirements are fully satisfied by willow, linden and aspen wood. Depending on the thickness of the tree trunk, the ridge is split into two or four parts, called splitting. Rectangular blanks are cut out of it. Each piece is trimmed in the middle to a certain thickness and then steamed.

There are many known ways to steam wood before bending, for example at a fire. In the first method, the workpiece was soaked and then heated over a flame; in the second, it was buried in the ground at the site of the future fire. After a certain timeWhen the fire died out, the coals were raked and the steam-enveloped pieces were removed from the ground. They were immediately inserted into the halo - a device for bent rocker arms, arches, sled runners and rims.

You can steam the workpiece using a blowtorch. The workpiece soaked in a pond, river or stream is heated in the middle with a blowtorch until steam appears. To prevent the wood from burning or (even worse) charring, the flame is kept at the optimal distance, which is determined experimentally.

The heated workpiece is inserted into a bending device, which is a massive shield with beams stuffed on it. A beam, one of the edges of which corresponds to the bend of the rocker arm, is called a template, and one with a straight edge is called a stop. Having inserted the workpiece into the bending device, two wedges are driven in between it and the stop on both sides. Instead of two wide ones, you can hammer in several narrower wedges. When wedging, the workpiece will bend and press tightly against the template bar.

Cooperage. How to make a comfortable rocker

Rice. 2 Making a bent rocker: a - steamed blank in a bending device; b - bending the workpiece using wedges; c - trimming a bent workpiece

The bent workpiece is dried in a bent device, which should be located in a heated room or in any other place with sufficient high temperature. When the workpiece dries after a few days, the shoulder part of the rocker takes on an arched shape. The massive ends of the workpiece are cut off on both sides so that the resulting layers go at right angles to the curved shoulder part. Then hooks are cut out at the top of each end of the beam for hanging buckets. If desired, hooks are made from metal strips that are screwed to the wood with screws.

The finished rocker is treated with scrapers or pieces of window glass, sanded with sandpaper, then impregnated with hot drying oil and painted with oil paints. If carving is used instead of painting, then the rocker is impregnated with drying oil last.

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Ministry of Agrarian Policy of Ukraine

State Committee of Fisheries of Ukraine

Kerch State Marine Technological University

Department: “Equipment for food and fish processing industries”

COURSE PROJECT

in the discipline: “Technological foundations of mechanical engineering”

Project manager V.V. Manuilov

2012

1. Part Description

3. Manufacturability analysis

4. Selection of technological bases

5. Development of the technological route of the process

7. Calculation of cutting conditions

1. Part Description

Rocker arm is a moving part in the form of a shaped rod or plate with holes or pins, making an incomplete revolution around a fixed axis. It is essentially a double-armed lever that swings around a central axis. Being part of many machines and mechanisms (engines internal combustion, drilling rigs, scales, etc.), the rocker arm transmits forces to the rod attached to it, the pusher, the valve, the connecting rod, etc. The rocker arms are made of unequal arms. The shoulder located above the valve is performed 30-50% longer than the shoulder facing the bar. This allows you to obtain the necessary valve movements with small movements and accelerations of the pusher, and therefore reduce the inertial forces acting in the valve mechanism.

In this course project we will consider the development of the technological process for manufacturing the rocker arm of the gas distribution mechanism of the D-50 engine.

The short arm of the rocker arm has a threaded hole for an adjusting screw and a channel for supplying oil to the spherical surface of the rod and screw. On the other arm of the rocker arm there is a spherical surface (the rocker arm) that rests on the valve stem. In the middle part there is a smooth hole for the rocker arm swing axis. The rocker arm is kept from axial displacement by a thrust washer and a retaining spring ring.

2. Selecting the type of workpiece and method of obtaining it

The choice of method for obtaining a workpiece depends on the service purpose and cost-effectiveness of manufacturing the part and has a significant impact on the nature of the technological process, labor intensity and cost-effectiveness of processing.

Taking into account the required quality of the part, the requirements for geometric dimensions, surface roughness, production efficiency, the specifics of the part material, its good casting properties, fluidity and low linear shrinkage, we choose the method of producing the workpiece - casting in a shell mold. Type of production - serial.

Shell casting is a method of producing shaped castings from metal alloys in molds consisting of a mixture of sand grains (usually quartz) and synthetic powder (usually phenol-formaldehyde resin and pulverized bakelite). It is preferable to use clad sand grains.

This method of obtaining a workpiece is preferable, since the following factors are taken into account when obtaining the “Yoke” part:

1) The consumption of molding sand is 8-10 times less than when casting in sand molds.

2) Hardening of the mixture directly on the model ensures high dimensional accuracy. The use of fine-grained sand makes it possible to obtain molds with a clean and smooth surface. Allowances are 0.5-1.5 mm.

3) Possibility of mechanization and automation of labor.

3. Manufacturability analysis

blank rocker arm engine allowance

The manufacturability of a product is considered as a set of product design properties that determine its adaptability to achieving optimal costs during production, operation and repair for given quality indicators, output volume and work conditions. The main task of ensuring the manufacturability of a product design is to achieve optimal labor, material, fuel and energy costs for design, preparation, manufacturing and installation outside production. A casting is considered technologically advanced if its design complies general principles ensuring the quality of workpieces during casting and the prevailing specific production conditions. High quality casting is ensured by: the use of a casting alloy with high fluidity and the optimal configuration of the casting, which makes it possible to use a simple casting mold that provides for simultaneous or directional solidification of the alloy and free removal of the casting (model) from the mold. In the design of the casting, it is also necessary to take into account real production capabilities: the availability of certain equipment for preparing the alloy and forming the casting for a given volume of production. The casting configuration is simple, does not require a complex shape, the casting alloy has the necessary casting properties and we can conclude that the part is manufacturable.

4. Selection of technological bases

When choosing a technological base for a given workpiece, we focus on the principle of unity of bases.

The principle of unity of bases is that the same surfaces of the part are used as technological or measuring bases in various operations of the technological process. The application of the principle of unity of databases allows us to eliminate the occurrence of processing and assembly errors associated with changing databases

Based on the principle of basing, it is advisable to first process the basing plane of the part, the base for installation, because The required geometric dimensions are determined relative to this plane. Technological base (installation) - outer surface with a diameter of 30 mm. The guide and support base are selected based on the conditions for ease of installation of the part.

5. Processing route

005 Procurement.

We obtain the workpiece by casting.

010 Milling.

Mill size 30+D mm.

Mill the ends of the surface Ш 18

015 Drilling

Drilling a hole for an M10 thread, maintaining a size of 33.5+ - 0.3

Drilling a hole Ш 4.4…..5.0 mm, maintaining size 18 +0.5, angle 20 0 for a length of 30 mm

020 Lathe Boring diameter Ш21Н9.

Chamfer

025 Turning

Thread cutting. Cutting occurs using a tap. The cutting part is made of high-speed steel, the shank is 40X steel.

030 Thermal. Harden to HRC 49-57

035 Flushing.

Wash the part

6. Determination of allowances and operational dimensions

Allowance is a layer of material removed from the surface of the workpiece in order to achieve the specified properties of the machined surface of the part.

The minimum allowance required for processing the “Yoke” part is determined using the formulas:

a) when processing external and internal surfaces (double-sided allowance):

2Z min =2[(Rz+h) i -1 +

b) when sequentially processing opposing surfaces (one-sided allowance):

Z min =(Rz+h) i -1 +

where Rz i -1 is the height of profile irregularities at ten points at the previous transition;

h i -1 -- depth of the defective surface layer at the previous transition (decarburized or bleached layer);

The total deviation of the surface location (deviation from parallelism, perpendicularity, coaxiality) at the previous transition;

Error in installing the workpiece at the transition being performed.

The total allowances Z 0 max and Z 0 min are found as the sum of intermediate processing allowances:

Z 0 max =? Z i max ;

Z 0 min =? Z i min ;

Allowance for processing end surfaces Ш 30 by milling:

Rz =40 µm; h i -1 =160 µm; = 110 µm

Z min =40+160+30+110= 340 (µm)

Minimum size:

a) 30 - 0.18 = 29.82 (mm)

b) 29.82+0.39 = 30.21 (mm)

where 0.39 is the tolerance for the size of 30 mm, corresponding to the specified quality.

Maximum size:

a) 29.82+0.18 = 30 (mm)

b) 30.21 + 0.39 = 30.6 (mm)

Maximum allowance:

30.6 - 30 = 0.6 (mm)

Smallest allowance:

30.2-29.8 = 0.4 (mm)

Overall largest allowance:

Z 0 max = 0.6 (mm)

Overall minimum allowance:

Z 0 min = 0.4 (mm)

Allowance for processing end surfaces Ш 18 by milling:

Deviation of the flat surface of the casting from flatness (warping);

Rz =40 µm; h i -1 =160 µm; = 100 µm

Z min =40+160+30+100= 318 (µm)

Minimum size:

a) 14.5 - 0.13 = 14.37 (mm)

b) 14.37+0.33 = 14.7 (mm)

where 0.33 is the tolerance for the size of 18 mm, corresponding to the specified quality.

Maximum size:

a) 14.37+0.13 = 14.5 (mm)

b) 14.7 + 0.33 = 15.03 (mm)

Maximum allowance:

15.03 - 14.5 = 0.53 (mm)

Minimum allowance:

14.7- 14.4 = 0.3 (mm)

Overall largest allowance:

Z 0 max = 0.53 (mm)

Overall minimum allowance:

Z 0 min = 0.3 (mm)

Allowance for thread cutting:

Cutting internal threads begins with drilling a hole and chamfering for the entry of the tap. The diameter of the hole, depending on the thread pitch, is selected using a reference table.

Allowance for machining hole Ш 21H9:

Machining route: rough and finishing turning.

(µm)

r = K y

where r is the magnitude of residual spatial deviations

K y - refinement coefficient

r 1 = 211 0.05 = 10.55 (µm)

2 Z min =2(40+160+) = 2* 419 (µm)

2 Z min =2(20+20+) = 2* 100 (µm)

Minimum dimensions:

20.948+0.13=21.078 (mm)

21.078+0.21 = 21.288 (mm)

Maximum dimensions:

20.948 +0.052 = 21 (mm)

21.948+0.13= 21.208 (mm)

21.288+0.21 = 21.498 (mm)

Minimum allowances:

21.078-20.948=0.130 (µm)

21.288-21.078= 0.210(µm)

Maximum allowances:

21.208 - 21= 0.208 (mm)

21.498-21.208 =0.290 (mm)

Overall largest allowance:

Z 0 max = 0.208+0.290=0.498 (mm)

Overall minimum allowance:

Z 0 min = 0.130+0.210= 0.340 (mm)

7. Calculation of cutting conditions

Milling

We choose a horizontal milling machine 6N80, its characteristics:

Dimensions of the working surface of the table, mm………….200*800

Distance from spindle axis:

to the table…………………………………20-320

to the trunk……………………………………………………….123

The greatest distance of the axis of the vertical guides to the rear edge of the table…………………………………..…….240

Number of T-slots………………….3

T-slot width……………………14A 3

Largest:

table rotation angle in degrees………………±45

moving the table:

longitudinal……………………………………...500

transverse………………………………………………………160

vertical………………………………….300

Morse taper of spindle holes GOST 836-62…………2

Number of spindle stages………………………12

Number of table feed stages……………………12

Table feed:

longitudinal……………………………..…25-1120

transverse………………………………….18-800

vertical………………………………….9-400

Power of the main electric motor in kW.........3

Overall dimensions, mm:

length........……… …………………………1360

width.........……………………………..1860

height……………………………………1530

Weight in kg………………………………...1150

The cutting tool used is a cylindrical cutter made of high-speed steel L=50 mm, cutting part material T15K6.

Feed when milling with a cylindrical cutter made of high-speed steel with a machine power of up to 5 kW, medium hardness AIDS, for steel 0.08-0.12 mm per tooth.

The milling depth is assumed to be equal to the machining allowance. For rough milling after casting and the length of the machined area is 30 mm, the allowance is 0.5 mm. For a surface with a diameter of 18 - allowance (cutting depth) 0.4 mm

Number of revolutions of the cutter:

We specify the rotation speed according to the machine data: n f = 2100 rpm;

Let's determine machine time

i - number of passes;

Cutting force:

The value of the coefficient and exponents in the formula for determining the cutting force during milling.). For steel

Cutting power:

Milling a surface with a diameter of 18 mm

Number of revolutions of the cutter:

We specify the rotation speed according to the machine data: n f = 1700 rpm;

Let's determine machine time

Cutting force:

Cutting power:

Boring a hole

Selecting a horizontal boring machine 2654

Machine layout type…………….………..B

Dimensions of the working surface of the table (width * length) ... 1600 * 2000

Diameter of retractable spindle……….…….…150

Spindle bore taper…………..metric 80

Movements:

retractable spindle longitudinal........….……..1240

radial caliper…………….………….….240

transverse…………………….………………..1800

front pillar:

longitudinal…………………….………………...1800

faceplates………………………………….3.75-192

Feed in mm/min:

retractable spindle……………………..…2-150

spindle head……………………....1-750

Selection of cutter and its parameters:

Boring tool holder with a carbide insert. GOST 9795-84

t - cutting depth, t=0.42/2 mm;

According to reference data, select speed V = 120 mm/min

Speed:

We specify the rotation speed according to the machine’s passport data: n f = 1800 rpm;

We specify the speed based on the actual rotation speed:

Let's determine machine time

l 1 - infeed value, l 1 =t/tgt=2.76/tg95°=0.25mm;

l 2 - overtravel value, l 2 =1...3mm;

l=30mm - turning length;

i - number of passes;

Determination of cutting forces

Constants for a given operation;

Correction factor;

Depends on the quality of the processed material;

Depends on the cutter parameters;

204; = 1; = 0,75; = 0; = 0,75; = 1,08; = 1,25; = 1

0,751,081,251=1,01

Determination of cutting power

DRILLING OPERATION

Select a radial drilling machine 2E52:

The largest nominal drilling diameter………...25

Diameter of the circle described when the sleeve rotates

his end…………………………………1120

Distances:

from the end of the spindle to the table surface…….....325-852

from the end of the spindle to the surface of the foundation slab......0-900

from psi spindle to rack (spindle overhang)…………500

The largest vertical movement of the hose along the column....890

Morse taper of spindle holes.....……..3

Number of spindle speed steps.....……………8

Spindle revolutions per minute………………45-2000

Number of spindle mechanical feed stages ……………9

Power of the main electric motor in kW……….……3.2

Dimensions:

length.........................……………….1130

width........................………………805

height........................……………….2290

Weight in kg.………………………..….980

1) Drilling a hole Ш8.5mm

2) 1 Drilling hole Ш5mm

We choose spiral drills equipped with hard alloy plates (VK15) for drilling steel with a conical shank. GOST 22736-77 and TU 2-035-636 - 78. Drill diameter d = 530 mm, working part length 60125 mm, total drill length 140275 mm, Morse taper No. 1-4. The angle of inclination of the grooves is 10-45 0.

For drilling diameters up to 12mm

Select drill diameters from the standard range

1 Drill Ш4.8 mm for drilling Ш5mm

2 Drill Ш8.3mm for drilling Ш8.5mm

The cutting depth is equal to half the drill diameter t=0.5D=4.25 mm

1) Cutting mode for drilling a hole Ш8.5mm

We specify the rotation speed according to the machine’s passport data: n f =950 rpm;

We specify the speed based on the actual rotation speed:

Let's determine machine time

i - number of passes;

Torque and axial force during drilling are determined by the following formulas:

Determination of cutting power

2) Cutting mode for reducing the hole Ш5mm

S=0.2-0.25 mm/rev; T=40

We specify the rotation speed according to the machine’s passport data: n f = 650 rpm;

We specify the speed based on the actual rotation speed:

Let's determine machine time

i - number of passes;

Torque and axial force:

Determination of cutting power

Threading

Cutting occurs using a tap. The cutting part is made of high-speed steel, the shank is 40X steel. Machine-manual GOST 3266-81

Cutting speed calculation:

We specify the rotation speed according to the machine’s passport data: n f = 450 rpm;

We specify the speed based on the actual rotation speed:

Let's determine machine time

i - number of passes;

P=1 - thread pitch

Determination of cutting power

8. Standardization of the technological process

In the process of calculating cutting conditions, the machine time To was determined for each operation.

The time to complete the operation is:

Tvsp - auxiliary time, Tvsp = 10-15%To;

Tobs - machine maintenance time, Tobs=3-5%To;

Tper - time of breaks, Tper = 3-5%To.

In addition, the operating time Toper is determined,

Toper=To+TVsp.

9. Description of the design of the device. Calculation of fixture

Since the workpiece is fixed outer surface rotation, then we choose a prism as a device. This device is suitable for drilling, milling and turning operations. At the moment of processing, when it is necessary to ensure reliable clamping, the workpiece is acted upon by the cutting moment M, which tends to rotate the workpiece around its axis, and by the axial force of the tool feed, pressing the workpiece to the supporting surface.

Let's determine the clamping force:

P z =2KM/

where M is torque;

K - safety factor;

f 1, f 2 - friction coefficients;

D z - workpiece diameter;

K= K 0 *K 1 * K 2 * K 3 * K 4 * K 5 * K 6 *

K 0 =1.5; K 1 =1; K 2 =1; K 3 =1.2; K 4 =1.3; K 5 =1.2; K 6 =1.5

P z =2*4.2*9.4/ = 2047 H

10. Calculation of the executive dimensions of the maximum caliber

According to GOST 25437-82, the maximum deviations of hole 21H9 are determined: ES=+52 µm;EI=0;

2. In accordance with GOST 24853-81, diagrams of the location of the caliber tolerance fields are constructed relative to the boundaries of the location of the hole tolerance field. The following values are determined from the same standard:

N - tolerances for the manufacture of plug gauge;

Z is the deviation of the middle of the tolerance field for the production of a pass-through plug gauge; Y is the permissible deviation of the size of a worn-out passage gauge (plug) beyond the tolerance zone; as well as tolerances on the shape of the calibers:

R-PRmax=D-EI+Z+H/2=21-0+0.009+0.004/2=21.011 mm;

R-PRmin=D+EI+Z-H/2=120+0+0.009-0.004/2=21.007 mm;

R-PRIZN=D+EI-U=120+0-0=21 mm;

R-PRsp=(R-PRmax) - H =120.011 -0.004 mm;

P-HEmax=D+ES+H/2=21+0.052+0.004/2=21.054 mm;

P-HEmin=D+ES-H/2=21+0.052-0.004/2=21.05 mm;

P-NESP=(P-HEmax) -H =21.054 -0.004 mm.

List of used literature

1. Ed. A.G. Kosilova and R.K Meshcheryakov Handbook of mechanical engineering technologist. - M.: Mechanical Engineering, 1985. vol. 1, 665 p.

2. Ed. A.G. Kosilova and R.K. Meshcheryakov Handbook of mechanical engineering technologist. - M.: Mechanical Engineering, 1985. vol. 2, 496 p.

3. Kozlovsky Yu.G., Kardash V.F. Annotated drawings of machine parts..- Kyiv. GIIO: Higher School, 1987. 224 p.

4. Gorbatsevich A.F., Shkred V.A.. Course design in mechanical engineering technology. - Minsk: Higher School, 1983. 256 p.

5. Toolmaker's Handbook. Ed. I.A. Ordinartseva. -L: Mechanical engineering, Leningrad branch. 1987-846 pp.

6. Sushkov O.D., Methodological instructions for implementation coursework in the course “Interchangeability, standardization and technical measurements” Kerch, KSMTU, 2009 - 59 pages;

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Rocker drawings. How to make a crane well with your own hands

So, let's start making the rocker arm

Stages of work on making a rocker for winter fishing:

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Ministry of Agrarian Policy of Ukraine

State Committee of Fisheries of Ukraine

Kerch State Marine Technological University

Department: “Equipment for food and fish processing industries”

COURSE PROJECT

in the discipline: “Technological foundations of mechanical engineering”

Project manager V.V. Manuilov

2012

1. Part Description

In this course project we will consider the development of the technological process for manufacturing the rocker arm of the gas distribution mechanism of the D-50 engine.

2. Selecting the type of workpiece and method of obtaining it

The choice of method for obtaining a workpiece depends on the service purpose and cost-effectiveness of manufacturing the part and has a significant impact on the nature of the technological process, labor intensity and cost-effectiveness of processing.

Shell casting is a method of producing shaped castings from metal alloys in molds consisting of a mixture of sand grains (usually quartz) and synthetic powder (usually phenol-formaldehyde resin and pulverized bakelite). It is preferable to use clad sand grains.

This method of obtaining a workpiece is preferable, since the following factors are taken into account when obtaining the “Yoke” part:

1) The consumption of molding sand is 8-10 times less than when casting in sand molds.

2) Hardening of the mixture directly on the model ensures high dimensional accuracy. The use of fine-grained sand makes it possible to obtain molds with a clean and smooth surface. Allowances are 0.5-1.5 mm.

3) Possibility of mechanization and automation of labor.

3. Manufacturability analysis

blank rocker arm engine allowance

4. Selection of technological bases

When choosing a technological base for a given workpiece, we focus on the principle of unity of bases.

5. Processing route

005 Procurement.

We obtain the workpiece by casting.

010 Milling.

Mill size 30+D mm.

Mill the ends of the surface Ш 18

015 Drilling

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