How to measure the radius ruler. How to measure the radius of the wheelbar. Why is it important to correctly determine the width of the car disk

Competent choice wheel disks depends on technical characteristicsdenoting all the parameters, namely width, diameter, departure, as well as DIA (landing diameter of the hub) and PCD (driving parameters).

You also need to know marking designation. It indicates the standard parameters of any types of wheelchairs:

Marking designations are indicated on inner side. Usually manufacturers duplicate them in the accompanying documents and on the package, if the product is new.

Disc parameters

To determine what is marked, you need to know the width and diameter of the wheel product.

Drilling, or breakdown

This is one of the most complex parameters for studying indicating the diameter of fastening bolts. The drilling is measured from the centerpiece zone to the opposite zone of the location of the element on the wheel.

Quite often, manufacturers specify the disk break parameters through the fraction depending on the number of holes for fixing.

Suppose indicators 6/222.25. The first digit demonstrates the number of drills for fasteners of the bolts, and the second number indicates the drilling in millimeters.

Disk departure

This indicator is marked by ET English letters. What is in disks and why it? The indicator denotes the distance from the plane of the wheel to the middle rim area. The collar surface of the wheel product indicates the clamping plane of the disk to the hub.

Departure parameters can be:

• with zero;
• with negative;
• with positive.

Zero departure indicates that the disc plane corresponds to its middle zone. Thus, the lower the indicator, the more the wheel product protrudes with outside car. If the departure indicator is increased, it means that the disk is deepened in the inner zone of the car.

It is also necessary to take into account the fact that, depending on the width of the product, the departure indicators differ. Manufacturers indicate the accompanying documentation for the vehicle. Less departure value for disks with a large width.

Diameter and other disk parameters schematically

What is HUMP (H)?

Hamp is a rings on the disk rim. This element is used as protection from the scope automotive tire. Typically, 2 Hampa is used for the wheel (H2).

In some cases, the Hamp may not be used or only one applies - depending on the configuration of the car. Hampov varieties:

1. combined (CH);
2. flat (Fh);
3. assymmetric (AH).

Disc parameters PCD.

The PCD value indicates the circle diameter of the center holes on the wheel disk. That is, it is the diameter of the holes for fastening the bolts.

Dia disk parameter

The DIA parameter indicates a dymeter of the opening located in the center of the disk. Casting manufacturers prefer to create a large diameter of the DIA centered hole. This is done so that the discs are used and universal for any types of cars.

Despite the fact that the size of the hub may differ depending on the model vehicleThe car is installed using a transition ring, sleeves.

Marking

As an example, consider the labeling of the wheel rim 9J x20h PCD 5 × 130 ET60 DIA 71.60:

1. Figure 9 indicates the width measured in inches. To translate inches in Sortima, the overall indicator is multiplied by 25.4.
2. The letter J indicates the elements of the design: the shape of disk clouds. This parameter does not play an important role when choosing.
3. The letter x denotes the disk delicacy.
4. Figure 20 denotes the diameter of the landing of the wheel product. This indicator corresponds to the landing of the automotive tire.
5. The letter H denotes the presence of one HAMPA or protrusion on the rim.
6. Abbreviation PCD 5 × 130, where digit 5 \u200b\u200bpoints to the number of drills for fastening nuts or bolts and the number 130 indicates their PCD diameter in millimeters.
7. ET60 marking indicates disk departure. In this situation, the indicator is 60 mm.
8. The value of Dia 71.60 denotes the diameter of the center drilling. Usually, DIA corresponds to the landing of the hub and is indicated in millimeters. If the DIA is larger than the hub diameter, then the centering ring for planting is used to set the disk.

The label also includes information:

ISO, SAE, TUV - These abbreviations indicate the organization that perform the wheelchair, similar to the Russian GOST. Standards are also designated that matches the wheel marking.

Maxload indicates the permissible load on the car wheel. This indicator is indicated in kilograms and pounds.

What does the 700C parameter denotes?

Such a designation is used for large types of wheels on SUVs and Niva. According to the adopted ISO classification, this indicator is 29 inches. Typically, the wheels with the 700C parameters are used for off-road races.

Due to the use of 29 inches wheels:

• improve management indicators;
• the braking path on the ground surfaces is reduced and aerodynamics increase;
• increases the cargo of the car on soft soils and sands;
• the ability to install powerful brakes.

To select discs corresponding to this or another type of car, it is recommended to determine the wheel diameter and analyze the label indicated on the rim. You should also not forget that the safe ride by car is ultimately depends on this element.

Source Kolesadom.ru.

Reading time: 4 minutes

Car discs not only improve appearance vehicle, but also increase the smoothness of the stroke. Thanks to mine unique properties, modern developments provide the most comfortable and safe ride for any climatic conditions. By purchasing new designs, motorists are repeatedly faced with a problem, how to choose them correctly. This question is relevant both among beginners and experienced drivers. There are many parameters of the structures that need to be determined in advance to improve challenges Auto. For example, the main parameter is the width of the disk responsible for the safety of the driver / passenger.

Disc width

As a rule, the diameter and placement of the holes are far from the most important parameters when choosing components. In this case, the marking indicated on the back of the product is understandable not to all motorists. Picking up structures for your own car, you must definitely determine the possible width for this size tires

Design width

Choosing automotive discs, you need to take into account the dimension of the tire. With a diameter, it usually happens everything is clear, for example, a tire with dimension R15 should be installed on the wheel in diameter 15. Basically, the problem arises due to the determination of the width of the tire and disk.

Table: Width of the wheel, profile height in mm

Calculation can be carried out independently. For this, you can consider an example for a bus width of 215 mm and diameter 16.

• The width of the rubber is denoted by centimeters: 215 mm \u003d 21.5 cm.
• Next, you need to translate the resulting value in inches: 1 centimeter \u003d 2.54 inches, divided 21.5 to 2.54, it turns out to be 8.46. The amount can be rounded to 8.5.
• 25-30% taken from the value, in this embodiment 2.38 leaves.
• The resulting number can be subtracted from the width of the tire and rounded to the tenths 8.5 - 2.38 \u003d 6.1.
• The size of the product rim should be 6.1 inches or 155 mm.
• Constructions that have a diameter of up to 14 inches, their possible error is determined from 0.5 to 1.
• Products that have a diameter of 15 inches are found with an accuracy of up to 1.5.

Why is it important to correctly determine the width of the car disk

To find out what is particularly affected by the width wheel Disc, every car owner should understand that with any deviation from the requirements of the manufacturer's factory technical parameters Designs may fail in the suspension. This adverse factor contributes to the rapid wear of components, as well as partitions. Without taking into account each parameter, you can encounter the destruction of the structures while driving the vehicle.

What is measured width of wheeled products

Before you choose the appropriate products for the car of any brand, it is necessary to consider the design example of the design: 6.5 14 4 × 100 ET45 D54.1:

• 6.5 - the width is determined;
• 14 - diameter of the design;
• 4 × 100 - information about fixing the structure;
• ET45 - departure;
• D54.1 - the diameter of the planting hole.

Low profile models are distinguished by stability. Therefore, before measuring the width of the design on the car of any brand, it is better to check all the information in advance that is indicated on the label. For increase high Speed \u200b\u200bCharacteristics It is necessary to take into account the recommendations of the manufacturer's plant.

7J disk parameters in centimeters

J is one of important parameterswhich indicates the features of the design side Zakrain Rim wheelbarrow. Typically, the labeling is most often indicated by the following combinations: j, jj, jk, k, b, d, p.

What is affected by the width of the car

Each cast or forged disk needs a personal version of rubber, which is suitable for the main parameters of the manufacturer. In case of an erroneous choice, you can encounter a number of problems. With a diameter, it is difficult to guess, because it is problematic that is incorrect. But the width is quite simple in the width indicators. Too narrow or wide structures will adversely affect the project profile of the tire. This will lead to a deterioration of the characteristics, for example, to a decrease in the stiffness of the sidewall.

What influence has the width of the autoconstruction

Many are often wondering what the wheelb width is affected. Experts argue that the size of the product of the product must be 25% less than the width of the rubber profile. For the presented size 195/65 R15 91 T, the design width can be calculated as follows:

• First calculated the profile width.
• Next 195 should be divided by 25.4, as a result, it turns out 7.68 inches.
• From this value it is necessary to take 25%, and then the result is rounded.
• The formula is as follows: 195 / 25.4-25% \u003d 5.76.
• Next, the number needs to be rounded and the disk is a width of 6 inches.

Without replacing rubber, put components of an increased width makes no sense, the behavior of the machine is changing only within the measurement error. If the disc is heavy, then it contributes to the deterioration of the smoothness of the stroke and handling of the vehicle.

Kolesa.Guru source

The wheel drive is one of the most responsible parts binding the car with an expensive through the bus. When replacing rubber or buying new disks, it is often necessary to learn the steam parmeters. Decoding the labeling of disks and other designations to them will help to deal with all the parameters and characteristics of your wheels.

Most characteristics of the wheeled disks affect the safety of the ride and the duration of the trouble-free suspension. When choosing disks, it is necessary to find out how the models with what characteristics are allowed to use on your car. Only, according to all requirements, they can be installed on the machine.

On our site there is already an instruction on decrypting tire marking, and now we will explain how to decrypt the labeling on the wheels.

You can also use our visual tire calculator.

Marking discs

Stamped I. alloy wheels For passenger cars have the same standard designation (labeling). Certification of discs in the territory of the EU countries is carried out according to UN / ECE 124.

As an example, you can decipher one of the options for labeling wheels: 7.5 J x 15 H2 5x100 ET40 D54.1

Decoding this marking will be as follows:

Rim Width (Rim Width)
The figure of 7.5 in the example of the marking indicates the distance between the inner edges of the rim in inches. This indicator is taken into account when choosing a tire, since each tire has a specific range of rim width. It is best when the rim width is on average tire range.

Rim Edge Type (Flange)
The Latin letter J in the disk marking indicates the shape of the rim. This is a place in which the disc is connected to the bus. Among the most common designations for passenger cars are found: p, d, b, k, jk, jj, j. Each letter hides several parameters:

• round radius,
• profile contour form
• shelves tilt angle
• height height, etc.

Most often in modern passenger cars It is encroaching in the form of J. All-wheel drive models Usually completed with discs with the designation type JJ.

Rabbing rims of a wheeled disk have an impact on the installation of a tire, a mass of balancing weights, stability of tires to displacement in extreme situations. Therefore, despite the external similarity of the disks JJ and J, it is necessary to give preference to the edge of the rim, which the automaker recommends.

Body detacity
The sign "X" suggests that the rim is carried out in an inexplicable form and is a single whole, and the sign "-" indicates that it consists of several components, and it can be disassembled and assembled. Dear discs differ from folding structures with ease and greater rigidity.

Wheel wheels with rim "x" are designed to operate them with elastic tires, which is characteristic of passenger and small trucks. In the case of cargo tires that differ in rigidity, detachable disc designs are required. In another, it is simply impossible to install the tire on the wheel drive.

Mounting diameter (Rim Diameter)
The mounting diameter is the size of the landing rim of the wheel disc under the bus.

The mounted diameter is usually indicated in inches (in our example is a number 15). In everyday life, motorists are also called it with a radius of the disk. When the tire selection, this indicator must necessarily coincide with its mounting size.

The standard values \u200b\u200bof the mounting diameters of the disk for passenger cars and crossovers will be values \u200b\u200bfrom 13 to 21.

Ring protrusions or podcasts (HUMP)
The designation H2 is decoded as follows. Ring protrusions (champs) are with 2 sides of the disk. These subfolders are designed to fix the tubeless tire on the wheel disc. They prevent the air outflow in the event of an external tire effect. Other designations are applied:
H - Hump is only on the one hand,
FH - Podcast has a flat form (Flat Hump),
AH - at the protrusion asymmetric form (asymmetric hump), etc.

Location of mounting holes (Pitch Circle Diameter)
In labeling 5x100, the first digit indicates the number of holes in the wheel disk. The number 100 denotes the diameter of the circle on which the mounting holes are placed.

• The number of fasteners for passenger cars usually ranges from 4 to 6 pieces.
• Standard values \u200b\u200bof the circle diameter will be 98 ÷ 139.7.

Determine on the eye matching the size of the hub and the disk is not always possible. And the installation of the disk 98 instead of 100 can lead to the wheel distortion, which will cause the beyon, as well as spontaneous unscrewing bolts.

Disk departure (ET, EINPRESS TIEF)
Disk departure is the distance between the plane of the disk touch with the hub and the plane that passes through the center cross section Wheel disk. The value is expressed in millimeters, and the departure is as positive (ET40) and negative (ET-30).

The diameter of the planting hole (Hub Diameter, Dia)
The central (hub) seating wheel of the wheel disc is indicated in millimeters, for example D54.1. The diameter of the planting opening in passenger cars ranges from 50 to 70 mm. It is very important to accurately select the disk in accordance with the landing belt of the hub of the car.

Even with minor deviations of one of the parameters of the wheel disc from the requirements of the automaker, the threat appears accelerated wear Tires, which can lead to its destruction in an extreme situation (high speed, sharp braking, steep turn).

When you stop the machine around the engine, you can call the tow truck, wizard or leaving for help on "traveler". But when at high speed, the tire breaks or the wheel from the hub is taken away, it creates the danger of the driver's life, passengers and other participants road. Therefore, the wheels should always be in good condition and are under constant driver control.

When we choose a car for yourself, we appreciate in the main key features, such as machine dimensions, return and engine volume, gearbox type and other. But for everyday operation, other indicators are important, for example, a reversal radius. How does this parameter affect the driving, how is it measured, and what is it generally?

From the name of the parameter it is already clear that it means the radius (minimum) semi-rapidness described by the machine when the maneuver is reversed from the scene. The steering wheel should be turned to the end. It seems everything is clear, but this parameter has their own nuances.

How important is the parameter

The reversal radius is one of the components of the machine maneuverability, the greater its value, the vessels of the car requires more space. It affects the ability of the machine to turn around on a limited width of the road for one reception. With a small radius car easier to manage in urban environments, and it is also easier to park. Automakers in the desire to show their cars more maneuverable contribute to the documentation the value is minimal, that is, on wheels, from the flawbrice to the wrapping, because it is significantly less than the real one from the wall to the wall. So, when choosing a car for this parameter, we take into account the size of the front ot.

How important is the reversal radius

As measured

You can simply measure the radius: we note the starting position of one wheel (outer), turn to the end steering wheel, deploy to full 180 degrees, note the final position of the same wheel. Between the marks, you measure the distance, half of it and will be a radius of reversal. This size is minimum width Roads (exactly smooth part), which will allow you to turn into one right.

This in theory, in practice they will also have to take into account the size of the front of the car, this is the distance from the front axle to the tip of the bumper. The fact is that the width of the road is not always limited to a low border, the bumps often come, and the borders themselves can be up to a meter tall. And if the reversal radius fits well in perfect roadYou can not fit with high limiters. So the real radius is measured slightly harder - it is necessary on the outside of the bumper to install overns with chalk (can be on the rod), after the turn, the chalk will leave the real radius marks.

Parking Radius

Nuances

The main nuance or problem is in terminology, the turning radius, it is rather the term spoken, in fact, the diameter will correctly. AND different manufacturers There may be different indicators who radius, and who diameter should be considered and clarified. For example, for Prado from Toyota in advertising it is indicated that the machine has a folding diameter of less than six meters, while the machine itself is almost five meters. Such a diameter is simply impossible. In the guide, the same car speaks about a radius measured on wheels, that is, the value that can be considered correct. On some sites in other countries, the diameter itself is indicated, which is more than 11 meters, which is very similar to the truth.

Change whether the parameter is changed

Why does the reversal radius depend? First, from the dimensions of the car, they will change them, of course, it will not work. Secondly, on what angle of turning from the front wheels. In general, changing the radius without serious intervention in the main construction will not work. And this is a loss of warranty, as well as possible problems SO stable work. Usually, such rework can be found on the machines for drift, where the moves are made maximum. True, this is done not to reduce the radius of the turn, but to increase the corner of the drift, which can keep the car. Ordinary civil cars are better not to redo.

Drift Radius

Initially, it looks like this:

Figure 463.1.. a) The existing arc, b) the definition of the length of the chord segment and height.

Thus, when there is an arc, we can connect its ends and get chord long. In the middle of the chords we can spend a line, perpendicular chord and thus get the height of the segment H. Now, knowing the length of the chord and the height of the segment, we can first determine the central angle α, i.e. The angle between radii conducted from the beginning and end of the segment (not shown in Figure 463.1), and then the radius of the circle.

The solution to such a task was considered in detail in the article "Calculation of arched jumper", so here only I will give the basic formulas:

tG ( a./4) = 2N / L. (278.1.2)

but/ 4 \u003d arctg ( 2H / L.)

R. = H./ (1 - COS ( a./2)) (278.1.3)

As we see, from the point of view of mathematics there are no problems with the definition of the circle radius. This method allows you to determine the value of the arc radius with any possible accuracy. This is the main advantage of this method.

Now let's talk about the shortcomings.

The problem of this method is not even that it is necessary to remember the formulas from the school year of geometry, successfully forgotten many years ago - in order to remind formulas - there is an Internet. But the calculator with the ArctG, Arcsin function, and so on. There is far from every user. And although this problem also successfully allows you to solve the Internet, but it should not be forgotten that we solve a fairly applied task. Those. It is not always necessary to determine the circle radius with an accuracy of 0.0001 mm, the accuracy of 1 mm can be quite acceptable.

In addition, in order to find the center of the circle, you need to extend the height of the segment and postpone on this direct distance equal to the radius. Since in practice, we are dealing with not perfect measuring instruments, a possible error should be added to this, it turns out that the smaller the height of the segment with respect to the length of the chord, the greater the error may be taken when determining the center of the arc.

Again, we should not forget that we consider not an ideal case, i.e. This we so gave the curve of the Arc. In fact, it can be a curve described by a sufficiently complex mathematical dependence. And therefore, the radius and center of the circle found in this way may not coincide with the actual center.

In this regard, I want to offer another way to determine the circle radius, which I often use it, because this method determine the radius of the circle is much faster and easier, although the accuracy is significantly less.

The second method for determining the radius of the arc (the method of consecutive approximations)

So will continue the consideration of the existing situation.

Since we still need to find the center of the circumference, then for the beginning, we will begin at least two arc arms of an arbitrary radius from the points corresponding to the beginning and the end of the arc. Through the intersection of these arcs will be held direct on which the center of the desired circle is located.

Now you need to connect an arc crossing with a middle of chord. However, if we spend from the specified points not in one arc, but two, then this direct will pass through the intersection of these arcs and then look for the middle of the chord not at all.

If the distance from the intersection of the arcs before the start or end of the arc under consideration is greater than the distance from the intersection of the arcs to the point corresponding to the height of the segment, then the center of the arc under consideration is lower on the direct, conducted through the intersection of the arc and the middle of the chord. If less is the desired center of the arc above on the line.

Based on this, the next point is taken, presumably the corresponding arc center, and it produces the same measurements. Then the next point is received and the measurements are repeated. With each new point, the difference of measurements will be less and less.

That's all right. Despite the so-long and wisdom description, to determine the arc radius in such a way with an accuracy of 1 mm enough for 1-2 minutes.

Theoretically, it looks like this:

Figure 463.2.. Definition of the center of the arc by the method of consecutive approximations.

And in practice, something like this:

Photo 463.1.. Marking of the workpiece of complex shape with different radii.

Here I only add that sometimes you have to find and draw a few radii, because there are so many things in the photo.

How to measure the radius of the circle! ? I forgot how to measure you need to remind somebody! And got the best answer

Answer from Loch Silver [Guru]
ruler, measure the biggest distance of the circle, it will be diameter, Delhi in half will be the radius
Sky silver
Thinker
(9085)
i wrote-merry the lineup the biggest distance between two edges of the circle

Answer from freda bags[newcomer]
thank you

Answer from Iasiakovova[guru]
To determine the radius of the circle, you must first find its center.
To find the center we carry out chord (straight line connecting two points, located directly, on the circumference itself). We define the middle of the chord (section divide in half using a ruler). Through the middle, we carry out a straight line, perpendicular to the chord, that is, the angle is 90 degrees. Then spend one more chord and repeat everything with it the same as with the first.
Determine the point of intersection of perpendiculars. This point is the center.
. I will prolong any of the perpendicular to the intersection with the circle line. We measure the distance from the resulting intersection point to the center of the circle.
This distance will be a radius of this circle.

Answer from 2 response[guru]

Hey! Here is a selection of topics with answers to your question: how to measure the circle radius! ? I forgot how to measure you need to remind somebody!