CN104111026A - Multi-electrode-plate capacitive sensor based variable hole diameter measuring device - Google Patents

Abstract

The invention discloses a multi-electrode-plate capacitive sensor based variable hole diameter measuring device. A capacitive sensor structure with fixed electrodes is used in the production application and scientific research field currently and a measuring head of the capacitive sensor structure only can be applied to fixed hole diameter measurement and cannot be applied to hole measurement in a wide range. The multi-electrode-plate capacitive sensor based variable hole diameter measuring device comprises electrode plates, sliding blocks, a driving shaft, a casing, a driven bevel gear and a driving bevel gear; the top of the casing is provided with a plurality of sliding grooves; the center inside the casing is provided with a driven shaft; the driven shaft bears the driven bevel gear; the driving bevel gear and a driving shaft are fixed; the casing bears the driving shaft through a bearing and one end of the driving shaft extends out of the casing; the driven bevel gear and the driving bevel gear are engaged; every sliding groove of the casing is provided with the sliding block; threads at the bottom of every sliding block and planar threads at the top of the driven bevel gear are engaged; an electrode plate is fixed on the internal lateral wall of every sliding block; the electrode plates are uniformly distributed along the periphery. The multi-plate capacitive sensor based variable hole diameter measuring device can achieve variable hole diameter precise measurement and guarantee the measuring accuracy within the wide range.

Description

Change aperture measurement device based on capacitor with multiple electrode plates sensor

Technical field

The invention belongs to fine measuring instrument technical field, relate to aperture measurement device, be specifically related to a kind of change aperture measurement device based on capacitor with multiple electrode plates sensor.

Background technology

Along with the fast development in the fields such as machinery, Aero-Space, military affairs, minute sized processing and measurement are proposed to more and more higher requirement, high precision is the main trend of current science and technology and industrial development with microminiaturization.

Inside diameter measurement is one of important content of pore geometry amount measuring technique, has a lot, but owing to being subject to the restriction of bulk and the impact of measuring contact force, all have some defects for the method for inside diameter measurement.Capacitance type sensor is widely used in the measurement of hole diameter, and its advantage mainly contains: (1) not only can measure small through hole and blind hole, and can measure the size and dimension error of arbitrary section in aperture; (2) coordinate after different adapters, can measure the micro hole of all directions; (3) measuring system precision is high, with low cost, simple to operation.Yet the capacitor sensor structures that adopt fixed electorde in production application at present and scientific research field more, its gauge head only can be applicable to the measurement of a certain constant aperture, and can not carry out large range measuring aperture, thereby cause the range of application of capacitive transducer to be restricted, measure the transducer probe assembly that different apertures just needs different size.

Summary of the invention

The object of the invention is for the deficiencies in the prior art, a kind of change aperture measurement device based on capacitor with multiple electrode plates sensor is provided, this device can be realized the precision measurement that becomes aperture, effectively improve the efficiency of measuring, in relatively large journey, guarantee measuring accuracy, reduce the input cost of surveying instrument simultaneously.

The present invention includes battery lead plate, slide block, main drive shaft, housing, driven wheel of differential and drive bevel gear; The top of described housing offers a plurality of chutes that radially arrange along circumference; The bottom opening of described chute is in the top inner wall of housing; The inside center of described housing is provided with integrated driven shaft; Described driven wheel of differential is bearing on driven shaft by bearing; Described drive bevel gear and main drive shaft are fixed; Described main drive shaft is bearing on housing by bearing, and stretch out outside housing one end; Described driven wheel of differential and drive bevel gear engagement.In each chute of described housing, be equipped with slide block, the screw thread of every slider bottom all meshes with the flat thread at driven wheel of differential top; The madial wall of every slide block is fixed with an electrode plate; Described battery lead plate is cylindricality, and xsect is fan ring-type; All battery lead plates are uniformly distributed along the circumference.

Bottom and the end cap of described housing removably connect.

Angle between described driven wheel of differential and drive bevel gear axis is 90o.

The central angle that described battery lead plate is corresponding is 30～70 °.

Described battery lead plate place circle diameter adjustable extent is 10～25mm.

Beneficial effect of the present invention:

1, detecting electrode is adjustable in the radial direction, thereby realizes the precision measurement in multiple aperture, comprises the shoulder hole that through hole, blind hole, micro hole and aperture are more or less the same.

2, adopt capacitive transducer measuring principle, effectively improve the efficiency of measuring, the precision that assurance is measured in relatively large journey, reduces simultaneously and measures cost.

Accompanying drawing explanation

Fig. 1 is one-piece construction stereographic map of the present invention;

Fig. 2 is cut-open view of the present invention;

Fig. 3 is principle of work schematic diagram of the present invention.

Embodiment

As illustrated in fig. 1 and 2, the change aperture measurement device based on capacitor with multiple electrode plates sensor, comprises battery lead plate 1, slide block 2, end cap 3, main drive shaft 4, housing 5, driven wheel of differential 6 and drive bevel gear 7; The top of housing 5 offers four chute 5-1 that radially arrange along circumference, and bottom and end cap 3 are connected by screw; The bottom opening of chute 5-1 is in the top inner wall of housing 5; The inside center of housing 5 is provided with integrated driven shaft 5-2; Driven wheel of differential 6 is bearing on driven shaft 5-2 by bearing; Drive bevel gear 7 is fixing with main drive shaft 4; Main drive shaft 4 is bearing on housing 5 by bearing, and stretch out outside housing 5 one end; Driven wheel of differential 6 and drive bevel gear 7 engagements, and the angle between driven wheel of differential 6 and drive bevel gear 7 axis is 90o.Four slide blocks 2 are separately positioned in a chute 5-1 of housing 5, and the screw thread of four slide block 2 bottoms all meshes with the flat thread at driven wheel of differential 6 tops; The madial wall of every slide block 2 is fixed with an electrode plate 1; Battery lead plate 1 is cylindricality, and xsect is fan ring-type; The central angle of battery lead plate 1 correspondence is 60 °; Four electrode plate 1 are uniformly distributed along the circumference, and four electrode plate 1 place circle diameter adjustable extents are 10～25mm.

As shown in Figure 3, four electrode plate 1 form four capacitors with the hole wall for the treatment of gaging hole 8, ignore the impact of edge effect, each battery lead plate 1 and treat that the capacitance computing formula between gaging hole 8 is:

$C=\frac{\mathrm{\ζ\ϵL}}{\ln \frac{R}{r}}---\left(1\right)$

In formula (1), the specific inductive capacity that ε is air; L is the axial length of battery lead plate 1; R is the radius for the treatment of gaging hole 8; R is the lateral wall radius of battery lead plate 1, and ζ is the central angle of battery lead plate 1 correspondence.

By in formula (1) employing Taylor's formula is launched, and makes R-r=Δ r; Δ r is battery lead plate 1 and the radial play for the treatment of gaging hole 8, gets r=1000 Δ r, can obtain:

$\ln \frac{R}{r}=\ln \left(\frac{r+\mathrm{\Δr}}{r}\right)=\frac{\mathrm{\Δr}}{r}---\left(2\right)$

To in formula (2) substitution formula (1), can obtain:

$C=\frac{\mathrm{\ζ\ϵLr}}{\mathrm{\Δr}}---\left(3\right)$

The electric capacity C of four capacitors that four electrode plate 1 are measured, substitution formula (3), tries to achieve four electrode plate 1 and four values treating the radial play Δ r of gaging hole 8 respectively, then averages the aperture value of gaging hole 8 is treated in calculating

Be somebody's turn to do the principle of work of the change aperture measurement device based on capacitor with multiple electrode plates sensor:

Change aperture measurement device using this based on capacitor with multiple electrode plates sensor is as gauge head, and housing 5 clampings are upper at three-dimensional motion mechanism (as numerically-controlled machine, coordinate measuring machine), and measured workpiece is fixed on worktable.Estimate the pore size for the treatment of gaging hole 8, by rotating main drive shaft 4, drive drive bevel gear 7 to rotate, drive bevel gear 7 and driven wheel of differential 6 engaged transmission, driven wheel of differential 6 drives four slide blocks 2 to radially slide along circumference, thereby regulate the diameter of four electrode plate 1 place circumference, make it to adapt to the pore size for the treatment of gaging hole 8.Four electrode plate 1 are stretched into and treated in gaging hole 8, and four electrode plate 1 all load 5V voltage, can measure.Three-dimensional motion mechanism drives this change aperture measurement device based on capacitor with multiple electrode plates sensor along treating moving axially of gaging hole 8, in conjunction with main drive shaft 4, adjust the radial distance of four electrode plate 1, can realize the multiple precision measurement for the treatment of gaging hole, comprise the shoulder hole that through hole, blind hole, micro hole and aperture are more or less the same; The hole measurement to be measured that particularly aperture is 10～25mm, guarantees measuring accuracy, reduces simultaneously and measures cost.

Claims (5)

1. the change aperture measurement device based on capacitor with multiple electrode plates sensor, comprises battery lead plate, slide block, main drive shaft, housing, driven wheel of differential and drive bevel gear, it is characterized in that:

The top of described housing offers a plurality of chutes that radially arrange along circumference; The bottom opening of described chute is in the top inner wall of housing; The inside center of described housing is provided with integrated driven shaft; Described driven wheel of differential is bearing on driven shaft by bearing; Described drive bevel gear and main drive shaft are fixed; Described main drive shaft is bearing on housing by bearing, and stretch out outside housing one end; Described driven wheel of differential and drive bevel gear engagement; In each chute of described housing, be equipped with slide block, the screw thread of every slider bottom all meshes with the flat thread at driven wheel of differential top; The madial wall of every slide block is fixed with an electrode plate; Described battery lead plate is cylindricality, and xsect is fan ring-type; All battery lead plates are uniformly distributed along the circumference.

2. the change aperture measurement device based on capacitor with multiple electrode plates sensor according to claim 1, is characterized in that: bottom and the end cap of described housing removably connect.

3. the change aperture measurement device based on capacitor with multiple electrode plates sensor according to claim 1, is characterized in that: the angle between described driven wheel of differential and drive bevel gear axis is 90o.

4. the change aperture measurement device based on capacitor with multiple electrode plates sensor according to claim 1, is characterized in that: the central angle that described battery lead plate is corresponding is 30～70 °.

5. the change aperture measurement device based on capacitor with multiple electrode plates sensor according to claim 1, is characterized in that: described battery lead plate place circle diameter adjustable extent is 10～25mm.