JPH0613967B2 - Milling plane direction measuring device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for measuring a magnetizing position and the like of a magnet roll having a plurality of magnetic poles on its surface.

(Prior Art) In an electrophotographic apparatus, a magnet roll having a plurality of magnetic poles on its surface is widely used as a means for transporting a magnetic developer. This magnet roll is, for example, a cylindrical magnet fixed to a shaft and subjected to predetermined magnetization, and is used as it is or with a cylindrical non-magnetic sleeve covered.

As a conventional device for measuring the magnetized position of a magnet roll, as shown in FIG. 6, a retractable jig 11 having a shape similar to the shaft 8 having the milling cut surface 7 has been used.

With this device, attach the shaft 8 to the jig 1 from the side with the milling surface.
When the needle 9 is inserted into No. 1, the needle 9 is attracted by magnetic force and points in the direction of the magnetic pole.

(Problems to be Solved by the Invention) However, the above-described conventional measuring apparatus has the following problems.

(1) FIG. 7 is a front view of the insertion jig 11 with the shaft 8 inserted. When the shaft of radius r _o having the chord AB and the jig of radius r _x having the chord A′B ′ meet at point A, the angle between the two chords is calculated and the perpendicular bisector of the chord A′B ′ is Since it passes through the center O, ∠B′AB = ∠M′OM = θ _o −θ _x .

Here, as the shaft and the milling depth, for example, r _o
= 2.5mm, ｜ ▲ ▼ ｜ = 1.7mm, ｜ ▲ ▼ ｜ ＝ 1.8m
Substituting m gives:

θ _o ＝ cos ⁻¹ (1.7 / 2.5) ＝ 47.15 ° θ _x ＝ cos ⁻¹ (1.8 / 2.5) ＝ 43.94 ° ∴∠B′AB ＝ θ _o −θ _x ＝ 3.21 ° From the above results, diameter 5mm milling depth It can be seen that the 0.8 mm thick shaft can rotate ± 3.2 degrees even if the center is fixed in a jig with a tolerance of 0.1 mm.

The tolerance of the magnetized position of the mag roll to be measured is generally ± 3 degrees, so a mechanism that makes the flat part parallel (set screw 1
Without 2) the measurement by this method is meaningless.

(2) Since a jig similar to the shaft is used, it is necessary to make a jig for each item and change the setup.

(3) Because the method of measurement does not output the result electrically,
Difficult to automate and quantify.

Therefore, an object of the present invention is to provide a milling surface direction measuring device that solves the above problems.

(Means for Solving the Problems) The milling surface direction measuring device of the present invention is based on the direction of a plane parallel to the central axis of the shaft, which is formed by cutting a part of a cylindrical shaft flat. In a device for measuring an angular position of a physical quantity having a plurality of peaks along the circumferential direction, which appears on the surface of a cylindrical body concentrically coupled with the cylindrical shaft, a means for rotating the cylindrical body,
A means for measuring the rotation angle of the cylindrical body, a means for measuring the physical quantity at each rotation angle position, and a radius from a predetermined point around the cylindrical shaft to the surface of the cylindrical shaft including the plane. A means for measuring a directional distance, a means for storing the rotation angle, the physical quantity and the radial distance measured by the respective means, and a means for storing the measured radial distance from the stored measured values. The present invention is characterized by comprising a calculation means for calculating a difference between a rotation angle and a rotation angle at which each of the peaks appears.

(Example) Hereinafter, the details of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention. The magnet roll 3 is a mechanism that is chucked on the encoder side, is pushed by the center from the direction of A, and rotates while holding a constant center.

The structure of the device is an encoder 1 for measuring an angle, a motor 2 for rotating a magnet roll 3, a magnet roll 3 as an object to be measured, a hall element 4 for measuring a magnetic force, a distance sensor 5, and a slide jig 6 for distance value conversion. And a milling surface 7 and a shaft 8 of the object to be measured.

According to this device, the measurement is performed as follows. While rotating the magnet roll 3 to measure the angular position, measure the distance from the external point to the shaft surface at the position with the milling surface, and at the same time measure the magnetic force value and output it to the XY recorder for one round. It becomes like.

Read the angle theta _f with the maximum value of the distance from this figure, when reading the angle theta _g as the maximum value of the force magnetizing angle Θ is theta _f and theta
_{Calculated as} the difference in _g .

The above data processing can be automatically output by a personal computer as shown in Table 1 by operation control by a sequencer, measurement and processing by a microcomputer as shown in FIG.

The line labeled "angle" in Table 1 is the above-mentioned magnetization angle. 921d means 92.1 degrees.

In the present invention, the magnetization angle can be measured without the slide jig 6 shown in FIG.

But the function becomes such a graph of the distance value R _A.theta. Under ideal conditions when direct measurements of FIG. 5 with respect to θ as (a) of FIG. 4 (a) is _R aθ = T-r _o cosα / Cos θ (0 ≦ θ ≦ α).

As shown in FIG. 4 (b), if there is a slide jig 6 having a plane wider than the milling surface and moving in the vertical direction following the rotation of the shaft, the distance value R _bθ to the _jig is shown in FIG. its function will be such a graph of b) is the _{R bθ = T-r o cos} (α-θ) (0 ≦ θ ≦ α).

In the above expressions representing Raθ and Rbθ, T represents the maximum distance from the sensor to the milling surface, and ro represents the radius of the shaft.

Now, in the two functions R _aθ and R _bθ , when the diameter of the shaft 8 is 5 mm and the milling depth is 0.8 mm, the change amounts ΔR _aθ and ΔR _bθ when the angle changes from 0 ° to 0.3 ° are ΔR _aθ = 0.000023 mm ΔR _{Since bθ} = 0.0097 mm, the amount of change near 0 degrees that you want to measure becomes large, and it is possible to sufficiently measure a change of 0.3 degrees with an ordinary sensor.

An ordinary sensor has a measurement accuracy of 0.001 mm or more, and if it outputs as an electric signal, it may be an optical type, a current type or a dial gauge, especially a dial gauge with a sufficiently wide tip has a slide cure. It has the same effect without the ingredients.

(Effect) According to the present invention, the following effects can be obtained.

(1) 0.3 degree measurement accuracy is possible with a distance sensor with an accuracy of 1μ.

(2) Since both the magnetic force measurement value and the angle measurement value are voltage outputs, automatic measurement using a microcomputer becomes possible
It took about 30 minutes to measure four lines, but each line can be measured in 14 seconds.

(3) The tolerance of the measurement re-actuality of the above microcomputer automatic measurement device is 0.3
It can be set within 6 degrees (resolution of the encoder used).

(4) If the slide jig 6 is set at a position with a milling surface and can be freely moved up and down, both the shaft diameter and the milling depth are optional within the measurable range of the distance sensor, so it can be moved to a position with a milling surface. With the structure, there is no need to change the setup.

[Brief description of drawings]

FIG. 1 is a diagram showing a measuring device of the present invention, FIG. 2 is an output data plot diagram, FIG. 3 is a diagram showing the function of the device, and FIG.
(a) is a diagram for explaining a direct measurement method, FIG. 4 (b) is a diagram for explaining a jig measurement method, FIG. 5 (a) is a diagram showing a direct measurement function, and FIG. b) is a diagram showing a jig measuring function, FIG. 6 is a diagram showing a conventional apparatus, and FIG. 7 is a diagram for explaining the maximum error of the conventional method. 1: Encoder, 3: Magnet roll, 4: Hall element, 5: Distance sensor, 6: Slide jig, 7: Milling surface, 8: Shaft, 9: Needle, 10: Scale, 11: Non-magnetic jig, 12: Set screw.

Claims (1)

[Claims] 1. A surface of a cylindrical body concentrically connected to the cylindrical shaft, which is formed by cutting a part of the cylindrical shaft into a flat surface, with reference to the direction of a plane parallel to the central axis of the shaft. An apparatus for measuring the angular position of a physical quantity having a plurality of peaks along the circumferential direction, which appears, and means for rotating the cylindrical body, means for measuring the rotation angle of the cylindrical body, and the rotation angles. Means for measuring the physical quantity at a position, means for measuring a radial distance from a predetermined point around the cylindrical shaft to the surface of the cylindrical shaft including the plane, and the means measured by the respective means Means for storing a rotation angle, the physical quantity and the radial distance, a rotation angle when the radial distance becomes maximum from the stored measured values, and when each peak appears Milling surface direction measuring apparatus characterized by having a calculating means for calculating a difference between the rotational angle.