CN203464876U

CN203464876U - Tool used for measuring cylindrical-thread pitch diameter

Info

Publication number: CN203464876U
Application number: CN201320629520.XU
Authority: CN
Inventors: 秦岚岚; 马晓霞; 王玉娣; 谢卫军; 梁衍能; 覃福疆; 覃洪东
Original assignee: Guangxi Yuchai Machinery Co Ltd
Current assignee: Guangxi Yuchai Machinery Co Ltd
Priority date: 2013-10-12
Filing date: 2013-10-12
Publication date: 2014-03-05
Anticipated expiration: 2023-10-12

Abstract

The utility model discloses a tool used for measuring a cylindrical-thread pitch diameter. The tool includes a base which is a square structure provided with a V-shaped groove, wherein the V-shaped groove is used for placing a to-be-measured cylindrical-thread workpiece; a fixing frame which is of a reversed-U-shaped structure and arranged at one end of the base, wherein the top part of the fixing frame is provided with locking bolts which rotate downwards and face the opening end of the V-shaped groove; a measurement frame which includes a U-shaped support and a measurement support, wherein the U-shaped support is installed at the other end of the base and the measurement support is arranged transversely on the U-shaped support; and three measurement pins which are hung on the measurement support during measurement, wherein each of the measurement pins abuts against the inner part of a to-be-detected cylindrical thread. The tool is capable of improving measurement efficiency and measurement precision.

Description

For measuring the frock of straight thread central diameter

Technical field

The utility model relates to mechanical length metering field, particularly a kind of for measuring the frock of straight thread central diameter.

Background technology

The pitch diameter of thread is an important parameter in screw measurement project, when measuring straight thread central diameter, high-precision straight thread central diameter is measured and all on universal comparator, is carried out, and the straight thread central diameter of low precision is more is to adopt three pins and outside micrometer to measure.

At present, when utilizing three pins and outside micrometer to measure low precision straight thread central diameter, the placement of three pin positions relies on feel and experience, be not specifically designed to measuring frock, utilize this metering system, measure efficiency lower, and operate very inconvenient, if operator's technical ability is skilled not, also can cause measured value out of true.Moreover in the actual measurement work of ， factory, the straight thread central diameter measurement of low precision has accounted for very large proportion, has a strong impact on measurement efficiency.

Utility model content

The utility model is in order to overcome defect in above-mentioned prior art, provides a kind of for measuring the frock of straight thread central diameter, has improved measurement efficiency and measuring accuracy.

For achieving the above object, it is a kind of for measuring the frock of straight thread central diameter that the utility model provides, and comprising: base, and it is the square structure with V-type groove, V-type groove is used for placing straight thread workpiece to be measured; Fixed mount, it is inverted U-shaped, and fixed mount is located at base one end, at fixed mount top, is provided with clamping screw, and clamping screw is rotated down and aims at V-type channel opening end; Measurement bay, it comprises U-shaped support and measurement support, U-shaped support is arranged on the base other end, measures support and is horizontally set with on U-shaped support; Surveyingpin, its number is three, during measurement, three surveyingpins are articulated in to be measured on support, and every surveyingpin is connected in straight thread to be measured.

In technique scheme, U-shaped support is arranged on the base other end by swivel bolt, and U-shaped support can be around rotation before and after base.

In technique scheme, at U-shaped, prop up top of the trellis and be provided with adjustment bolt, in adjustment bolt upper end, be provided with two clamp nuts, measure support and be clamped on U-shaped support by two clamp nuts.

In technique scheme, fixed mount is fixed on base one end by two trip bolts.

Compared with prior art, the beneficial effect the utlity model has: by design, with the end of V-type groove, sit, can be fast, simple positioning and clamping workpiece, improve and measure efficiency; By designing adjustable measurement bay, three pins can freely be found the best contact point with straight thread to be measured, greatly improve and measure efficiency and measuring accuracy.

Accompanying drawing explanation

Fig. 1 is of the present utility model for measuring the structural representation of the frock of straight thread central diameter;

Fig. 2 is the partial schematic diagram (surveyingpin and straight thread position relationship to be measured are shown) in Fig. 1;

Fig. 3 is the measurement key diagram of measuring straight thread central diameter in the utility model.

Embodiment

Below in conjunction with accompanying drawing, an embodiment of the present utility model is described in detail, but is to be understood that protection domain of the present utility model is not subject to the restriction of embodiment.

Of the present utility model is mainly to measure and design for the straight thread central diameter of low precision for measuring the frock of straight thread central diameter, when utilizing three pins and outside micrometer to measure low precision straight thread central diameter, the optimum position that need to find three pins to contact with screw thread, the optimum position that utilizes this frock accurately to find three pins to contact with screw thread, greatly improve the degree of accuracy of detection efficiency and measurement result, and avoided the measuring error brought due to operator's skill level.This frock is simple, practicality.

As shown in Figure 1, of the present utility model for measuring the frock of straight thread central diameter, this frock is positioned on smooth worktable and can uses, specifically comprise base 1, fixed mount 2, measurement bay (unmarked in figure) and surveyingpin 4, base 1 is referring to Fig. 2 with V-type groove 11() square structure, this tooling base is used aluminum alloy materials, has light, rustless advantage, V-type groove is used for placing straight thread workpiece to be measured, and V-type groove can design symmetrical structure in 90 °, fixed mount 2 is inverted U-shaped, it is made for metal material, at fixed mount 2 tops, be provided with through hole (not shown), on through hole, be welded and fixed nut 211, clamping screw 21 is screwed in hold-down nut 211 and can be rotated down and extends to V-type groove 11 openends, inverted U-shaped fixed mount is stuck in base 1 two sides, the fixing fixed mount 2 of two trip bolts 22 for every side, when straight thread workpiece 5 to be measured is placed in V-type groove, move forward and backward measured circle male screw workpiece and can freely adjust the position of workpiece, be rotated down clamping screw 21 clamping straight thread workpiece 5 to be measured, just workpiece can be fixed, realized fast, the object of simple positioning and clamping workpiece, improve and measure efficiency, measurement bay comprises U-shaped support 31 and measures support 32, U-shaped support welded top adjusting nut 331, adjusting bolt 33 lower ends is screwed on adjusting nut 331, in adjustment bolt 33 upper ends, be provided with two clamp nuts 34, U-shaped support 31 is arranged on base 1 other end by swivel bolt 311, and U-shaped support 31 can be around base 1 front and back rotation, measuring support 32 is that two length are that 12cm left and right, diameter are the round metal bars of φ 2, and it is clamped on U-shaped support by two clamp nuts 34, surveyingpin 4(is commonly called as three pins) specification be that choosing by tabling look-up of φ 0.866(tri-pins can obtain), during measurement, three surveyingpins 4 are articulated in to be measured on support 32, rotation clamp nut 34 is adjusted the height of measuring support 32, three pins can just be located by deadweight, rotation U-shaped support simultaneously, movable U-shaped support can drive three pins freely to fluctuate and find best contact point, the time that has relied on feel to place and locate while having saved without detection frock, and the possibility of having avoided three pins to drop, greatly improve the degree of accuracy of detection efficiency and measurement result, and can make the operator who lacks experience obtain the measurement result close with skilled operators, avoided the generation of larger error.When three pins contact in optimum position (referring to Fig. 2) with screw thread, finally utilize the outside micrometer of 25-50mm can measure (referring to Fig. 3), measured value M substitution formula can be drawn to pitch diameter of thread value d ₂(seeing below).

As shown in Figure 3, when measuring, outside micrometer is stuck on the measurement face S of surveyingpin, reads measured value M, by leg-of-mutton geometric relationship, can be drawn:

M = d_{2} + d_{0} (1 + \frac{1}{\sin α / 2}) - \frac{P}{2} \times \cot \frac{α}{2} .

?

d_{2} = M - d_{0} (1 + \frac{1}{\sin α / 2}) + \frac{P}{2} \times \cot \frac{α}{2} .

1, for metric system STRTHD α=60 °, d ₂=M-3d ₀+ 0.866P(formula 1)

2, for acme thread

During α=30 °, d ₂=M-4.8637d ₀+ 1.866P(formula 2)

During α=40 °, d ₂=M-3.9238d ₀+ 1.37375P(formula 3)

During 3, for inch screw thread α=55 °, d ₂=M-3.1657d ₀+ 0.9605P(formula 4)

In formula

D ₂the central diameter of-screw thread (mm)

M-miking gained size (mm)

D ₀-tri-pin diameters (mm)

The pitch of P-tested external thread gauge (mm)

α-tested form of thread angle

By the above-mentioned corresponding formula of measured value M substitution, can measure Correspondent cy linder pitch diameter of thread value.

Disclosed is above only specific embodiment of the utility model, and still, the utility model is not limited thereto, and the changes that any person skilled in the art can think of all should fall into protection domain of the present utility model.

Claims

1. for measuring a frock for straight thread central diameter, it is characterized in that, comprising:

Base, it is the square structure with V-type groove, described V-type groove is used for placing straight thread workpiece to be measured;

Fixed mount, it is inverted U-shaped, and described fixed mount is located at described base one end, at described fixed mount top, is provided with clamping screw, and described clamping screw is rotated down and aims at described V-type channel opening end;

Measurement bay, it comprises U-shaped support and measurement support, and described U-shaped support is arranged on the described base other end, and described measurement support is horizontally set with on described U-shaped support;

Surveyingpin, its number is three, during measurement, described three surveyingpins are articulated on described measurement support, and every described surveyingpin is connected in straight thread to be measured.

2. according to claim 1ly for measuring the frock of straight thread central diameter, it is characterized in that, described U-shaped support is arranged on the described base other end by swivel bolt, and described U-shaped support can be around rotation before and after described base.

3. according to claim 1 for measuring the frock of straight thread central diameter, it is characterized in that, at described U-shaped, prop up top of the trellis and be provided with adjustment bolt, in described adjustment bolt upper end, be provided with two clamp nuts, described measurement support is clamped on described U-shaped support by described two clamp nuts.

4. arbitrary described for measuring the frock of straight thread central diameter according to claims 1 to 3, it is characterized in that, described fixed mount is fixed on described base one end by two trip bolts.