CN88210020U - Slide caliper - Google Patents

Abstract

The utility model relates to a slide caliper, belonging to a tool used for measuring the length of a mechanical part. The utility model is characterized in that the slide caliper body is soft, and the slide caliper overcomes the disadvantage that the measuring range of the present slide caliper is short, therefore, the slide caliper can be used for measuring the length of the machine part in big size, such as the size measurement of the step of a long shaft. Compared with the present slide caliper, the measurement precision of the slide caliper is conspicuously improved. The utility model has the advantages of light weight, convenient operation and small size.

Description

Slide caliper

The utility model belongs to mechanical component dimensional measuring instrument, i.e. vernier caliper.

Easy to use, accurate characteristics that vernier caliper has, so be the mechanical component dimensional measuring instrument that generally adopts always, especially in the working site, it is the most frequently used dimensional measuring instrument.In recent years, big machinery is growing, and the linear measure longimetry of large scale mechanical component is cumulative many working day, survey instrument has been proposed the requirement of wide range.Existing vernier caliper then can not adapt to this requirement.It is all manufactured with rigid material, and it is very big that range is difficult for reaching, as present maximum be 2 meters, but very heavy, use inconvenience.

On the other hand, the linear measure longimetry of large scale mechanical component is measured such as the major axis step dimension does not still have easy, accurate survey instrument so far and can use it.

The purpose of this utility model just is to provide a kind of improved vernier caliper, and its range is big, is not only applicable to undersized but also is applicable to large-sized mechanical component linear measure longimetry.

The purpose of this utility model is achieved in that it comprises chi head, main scale, the secondary chi of vernier, and main scale one end is fixed on the chi head, and the secondary chi of vernier is connected movingly with main scale, and it is characterized in that: main scale is flexible chi band.This flexibility chi band preferably adopts the thin slice steel band, manufactures as manganese steel, steel measuring tape band material.Its measuring principle is same as existing vernier caliper fully.

Embodiment of the present utility model is by shown in the accompanying drawing 1, below in conjunction with detailed description the utility model.

Fig. 1 is a kind of concrete structure synoptic diagram of the utility model.

Fig. 2 is the utility model analysis of measurement errors synoptic diagram shown in Figure 1.

According to Fig. 1, the utility model comprises chi head 1, the flexible chi band 2 as main scale, vernier pair chi 3.Flexible chi band 2 preferably adopts thin slice steel band such as 65Mn spring steel or steel measuring tape band material to manufacture, thickness can be 0.25mm, softness, good springiness, indeformable, its length can reach 0.5～3M(and also can extend as required), its end also can add a draw ring 4, so that stretching flexible chi band 2 when measuring.During measurement, chi head 1 end that fixes is with flexible chi band 2 stretching getting final product.Its measuring accuracy can satisfy precision measurement requirement (seeing following error analysis for details) fully.

Measure error of the present utility model comprises following several respects:

1, blade and the axis of workpiece scale error (△ t1) that tilts and to cause:

This error has the three aspects: origin cause of formation: 1. measuring method is incorrect, and the 2. trueness error of flexible chi band 2 is 3. owing to make the error of perpendicularity that flexible chi band 2 that processing causes and chi head 1 are measured face.

With reference to figure 2, △ t1 can be calculated by following formula:

Δt ₁＝L－t＝ $\sqrt{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="88210020\_DRIMG1.png"\; state="\{\{state\}\}">t</figure-callout>}{}^2\mathrm{+h}{}^2}$ －t ………a

L: measured value

T: the true length of workpiece tested segment

H: blade axis and axis of workpiece side-play amount, it comprises---

I:, be 1.5mm/1000mm because the journal offset amount h1 that flexible chi band 2 precision cause gets regulation chi band linearity tolerance value.

Ii: the journal offset amount h2 that the error of perpendicularity of flexible chi band 2 and chi head 1 causes.

Iii: because the incorrect journal offset amount h3 that causes of measuring method.

h ₁, h ₂, h ₃Following relation should be arranged:

h ₂＋h ₃＜＜h ₁

If h ₂+ h ₃=h ₁Then maximum h=2h ₁

Then can and calculate following table 1 with a formula

2, the measuring error △ t2 that causes of workpiece shape:

This error depends on the machine tool accuracy of processing work fully, and is very small, can ignore.

3, the error △ t3 that causes of temperature variation:

This error will be considered measured workpiece and flexible chi band 2 linear expansion double factors simultaneously, because flexible chi band 2 is very thin, and very fast meeting and measured workpiece isothermal.

Getting measured workpiece is that (linear expansion coefficient α is 10.4 * 10 to casting pig ^-6Mm) and 45 steel (α=11.59 * 10 ^-6Mm), flexible chi band 2 is 65Mn steel (α=11.1 * 10 ^-6Mm), measured workpiece temperature departure standard degree ± 10 ℃.

Then at cast iron part △ t5=(11.1-10.4) * 10 * measurement size ... b

45 steel workpiece △ t5=(11.59-11.1) * 10 * measurement size ... c

The maximum error △ t4 of slide calliper rule that is calculated the flexible chi band 2 of different ranges by b, c formula lists following table 2 in.

Table 2 unit: mm

Measurement size	Casting pig △ t 4	45 steel △ t 4
			500	0.0035	0.00245
1000	0.007	0.0049
			1500	0.0105	0.00735
2000	0.014	0.0098
			2500	0.0175	0.01225
3000	0.021	0.0147

4, dynamometry changes the measuring error △ t that causes ₄:

According to Hooke's law: △ t ₄=(FL)/(EA) ... d

F: dynamometry to the regulation dynamometry (2kg) variable quantity,

L: flexible chi band 2 length

A: the cross-sectional area of flexible chi band 2 (is made as 0.25 * 10 ^-1* 12 * 10 ^-1=3 * 10 ^-2Cm ²)

E: the elastic modulus of flexible chi band 2 (is selected 65Mn steel, E=2.1 * 10 for use ^-6Kg/cm ²)

Calculate the maximum difference △ t4 that measures of slide calliper rule of the flexible chi band 2 of different ranges by the d formula, list following table 3 in.(B)

Table 3 unit: mm

5, the measuring error (△ t5) that causes in flexible chi band 2 manufacturings:

I: the error that the groove equipment precision causes: as adopting the domestic high precision optical dividing head, the maximum 0.0052mm of this error.

Ii: during groove because the error that the modified value of groove equipment corner causes: it is 0.0009mm((modified value 1 ")/(worktable corner 196 ") * 10 long 1mm=0.0009mm of scale to the maximum).

6, the measuring error (△ t6) that causes of parallax:

Because of secondary chi 3 scale values of vernier are generally 0.02mm, so parallax, is got maximum △ t less than 0.01mm ₆=0.01mm.

To sum up analyze, composition error △ t of the present utility model can obtain by following formula e:

△t＝ $\sqrt{\mathrm{△t}{}_1{}^2{\mathrm{+△<figure-callout\; id="3"\; label="t"\; filenames="88210020\_DRIMG1.png"\; state="\{\{state\}\}">t</figure-callout>}}_3{}^2{\mathrm{+△<figure-callout\; id="4"\; label="t"\; filenames="88210020\_DRIMG1.png"\; state="\{\{state\}\}">t</figure-callout>}}_4{}^2{\mathrm{+△t}}_5{}^2{\mathrm{+△t}}_6{}^2}$ …………e

Can calculate the composition error △ t of the present utility model of different ranges according to formula e, list following table 4 in.

(B)

Table 4 unit: mm

Seen that by last table measuring error of the present utility model is small, precision is very high.

The utility model has following advantage:

1. broad quantum is not only applicable to undersized and is applicable to large-sized mechanical component linear measure longimetry.

2. easy to use, at first, its measuring operation in light weight is convenient, in addition, and the placement of can curling of its flexible chi band 2, thereby be easy to carry.

3. the measuring accuracy height is less by known its measuring error of top error analysis; On the other hand, because its main scale be flexible, thus can guarantee that the blade axis is consistent with the measured workpiece axis during measurement, thus the measuring method of having avoided existing vernier caliper does not meet the defective of " Abbe criterion ", has improved measuring accuracy greatly.

4. cost is low, and its main scale can adopt the thin slice steel band to manufacture, and this greatly reduces cost.

Claims (3)

1, a kind of vernier caliper comprises chi head 1, main scale, the secondary chi 3 of vernier, and the main scale front end is fixed on chi head 1, and the secondary chi 3 of vernier is connected movingly with main scale, and it is characterized in that: main scale is flexible chi band 2.

2, by the described vernier caliper of claim 1, it is characterized in that: flexible chi band 2 adopts the thin slice steel band to manufacture.

3, by claim 1,2 described vernier calipers, it is characterized in that: flexible chi band 2 terminal band draw rings 4.

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