JPH0566134A - Azimuth adjusting method for magnetic rotary encoder - Google Patents

Abstract

PURPOSE:To directly adjust the inclination of a sensor body regardless of a circuit board. CONSTITUTION:After a sensor body 3 is adhered to a circuit board 4, the circuit board 4 is inserted to groove parts 10a, 11a of a holding member 8 to bring both the side parts on the lower end of the circuit board 4 in contact with a pair of compression springs 12, 13 provided on the bottom surface of the groove parts 10a, 11a. The standard surface 3a of the sensor body 3 is pressed in the bottom surface direction of the groove parts 10a, 11a against the spring force of the compression springs 12, 13, whereby the sensor body 3 is rotated to the holding member 8, and the circuit board 4 is adhered and fixed to the holding member 8 in this state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting the azimuth of a magnetic rotary encoder for adjusting the azimuth between a magnetic drum and a magnetic sensor.

[0002]

2. Description of the Related Art Generally, a magnetic rotary encoder has a magnetic drum 1 and a magnetic sensor 2, as shown in FIG. The magnetic drum 1 is made of a magnetic material and has magnetic patterns N, S, S, N, N, S, S, on its peripheral surface.
The magnetic pole pairs adjacent to each other are continuously formed at equal pitch intervals so that the adjacent magnetic pole pairs have opposite polarities. A rotating shaft protruding from a rotating machine such as a motor (not shown) is fixed to the center of the magnetic drum 1. The magnetic sensor 1 includes a sensor body 3 and a circuit board 4 on which the sensor body 3 is mounted, and the circuit board 4 is held by a holding member (not shown). The sensor body 3 is opposed to the circumferential surface of the magnetic drum 1 with a predetermined space, and is composed of, for example, a magnetoresistive effect element, and np + 1 for each magnetic pole pitch p of the magnetic patterns magnetized and arranged on the magnetic drum 1. / 4 p (however n
Is an integer) Two sets are arranged so as to be out of phase. Further, the magnetoresistive effect elements are arranged so as to face the magnetic pattern so that the respective magnetic directions thereof are orthogonal to the rotation axis. Therefore, when the magnetic drum 1 rotates, continuous signals having a phase difference of 90 degrees are output from the magnetoresistive effect elements of the sensor main body 3, and these signals are output via a lead wire (not shown) to the circuit board. 4 and obtain an incremental pulse by performing processing such as amplification, detection and matching in the signal processing circuit, and by this,
The displacement amount and rotation direction of the magnetic drum 1 are detected.

In the magnetic rotary encoder thus constructed, as shown in FIG. 8, when the center main body 3 is tilted with respect to the rotational axis direction of the magnetic drum 1, the signal output from the center main body 3 is output. Since the output value decreases,
It is necessary to perform work for adjusting the inclination angle θ of the center body 3 to zero, that is, so-called azimuth adjustment work.

Conventionally, this azimuth adjustment work is displayed on an oscilloscope or the like after the sensor body 3 is mounted on the circuit board 4 and an operator manually tilts the circuit board 4 in the clockwise direction or the counterclockwise direction. The output waveform was adjusted according to the location where the signal output value was detected most. However, in this method, since the azimuth adjustment work is performed manually, there is a problem that it takes a lot of labor and time and the assemblability is poor.

Therefore, as one means for solving such a problem, an azimuth adjusting device for adjusting the inclination of the circuit board on which the sensor body is mounted has been proposed, as disclosed in, for example, Japanese Patent Application Laid-Open No. 62-111201. ing. FIG. 9 is a front view showing a conventional azimuth adjusting device of this type.
Reference numeral 5 is a holding member, and 6 is an L-shaped body provided on the holding member 5. In FIG. 9, the same components as those shown in FIG. 8 described above are designated by the same reference numerals. That is, 2 is a magnetic sensor, 3 is a sensor body, and 4 is a circuit board.

In the conventional azimuth adjusting device shown in FIG. 9,
Each of the groove portions 5a and 5b of the holding member 5 that holds the circuit board 4 is provided with a protrusion 5c protruding upward in FIG. 9 and a protrusion 5d protruding rightward in FIG. Further, the L-shaped body 6 is rotatably attached to the holding member 5 via the screw 7, and the circuit board 4 is provided with the groove portions 5a and 5b.
It can be pressed toward. In this azimuth adjusting device, the circuit board 4 on which the sensor body 3 is mounted is inserted into the grooves 5a and 5b, and the L-shaped body 6 is screwed into the holding member 5.
Temporarily fix through the L-shaped body 6 around this screw 7
Circuit board 4 by pressing the top or right side of the
Slides while coming into contact with the protrusions 5b and 5d, whereby the inclination of the circuit board 4 with respect to the reference surface of the holding member 5 can be adjusted.

[0007]

By the way, in the above-mentioned prior art, the sensor main body 3 may be bonded to the circuit board 4 in a tilted state. Even if the inclination of the substrate 4 is adjusted, the sensor body 3
There was a problem that the inclination of could not be adjusted accurately.

The present invention has been made in view of the actual situation in the prior art as described above, and an object thereof is a magnetic rotary encoder capable of directly adjusting the inclination of the sensor body regardless of the circuit board. To provide a method for adjusting azimuth.

[0009]

To achieve this object, the present invention provides a sensor body facing a magnetic drum having a magnetic pattern in the circumferential direction, and a circuit board to which the sensor body is adhered and held by a holding member. In the azimuth adjusting method of a magnetic rotary encoder for adjusting the azimuth of a magnetic sensor, the sensor body is first adhered to the circuit board, and then the circuit board is inserted into the groove of the holding member. Both sides of the lower end of the circuit board are brought into contact with the pair of springs provided, and then the reference surface of the sensor body is pressed against the bottom surface of the groove against the elastic force of the spring. Thus, the sensor body is rotated with respect to the holding member, and in this state, the circuit board is bonded and fixed to the holding member.

[0010]

According to the present invention, as described above, the circuit board to which the sensor body is adhered is inserted into the groove portion of the holding member, and both side portions of the lower end of the circuit board are opposed to the pair of springs provided on the bottom surface of the groove portion. Are pressed against each other, and the reference surface of the sensor body is pressed toward the bottom surface of the groove portion against the elastic force of the spring, so that the circuit board is pressed toward the bottom surface direction of the groove portion, and Each spring is compressed. At this time, when the sensor body or the circuit board is tilted with respect to the holding member, since the compression amounts of the springs are different, the circuit board and the sensor body are rotated to adjust the tilt of the sensor body. Therefore, in this state, the circuit board is bonded and fixed to the holding member. With this, the inclination of the sensor body can be directly adjusted without any relation to the circuit board. For example, even when the sensor body is adhesively fixed to the circuit board in an inclined state, The inclination of can be adjusted accurately.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an azimuth adjusting method for a magnetic rotary encoder according to the present invention will be described below with reference to the drawings. 1 is a perspective view showing a magnetic sensor and a holding member of a magnetic rotary encoder in which an embodiment of the azimuth adjusting method of the present invention is used. FIG. 2 is a front view of the magnetic sensor of FIG.
1 is a front view of the magnetic sensor and the holding member of FIG. 1, FIG. 4 is a diagram illustrating a state during azimuth adjustment, FIG. 5 is a diagram illustrating another state during azimuth adjustment, and FIG. 6 is a further diagram during azimuth adjustment. It is a figure explaining the state of. 1 to 6, the same components as those shown in FIGS. 8 and 9 described above are designated by the same reference numerals. That is, 2 is a magnetic sensor, 3 is a sensor body, and 4 is a circuit board.

In a magnetic rotary encoder using the azimuth adjusting method of this embodiment, as shown in FIG.
The magnetic sensor 2 is held by a holding member 8, and this holding member 8 is a base 9 attached to a motor (not shown).
And a pair of protrusions 10 and 11 protruding from the base 9. A groove 1 is formed in the protrusions 10 and 11 so as to face each other and the magnetic sensor 2 is inserted therein.
0a and 11a are provided respectively. On the bottom surfaces of these groove portions 10a and 11a, that is, on the upper surface of the base portion 9, a pair of compression springs 12 and 1 which are arranged in parallel with the groove portions 10a and 11a and which can respectively come into contact with both side portions of one end of the circuit board 4.
3 is provided. In FIG. 2, a is the height of the center point of the sensor body 3, b is half the width of the circuit board 4, c is half the width of the sensor body 3, and d is the center of the sensor body 3. Height from point to reference plane 3a, e
Is the height dimension of the circuit board 4.

In this embodiment, when adjusting the azimuth of the magnetic sensor 2, the sensor body 3 is first bonded to the circuit board 4 to obtain the magnetic sensor 2. This magnetic sensor 2
As shown in FIG. 2, the reference surface 3a of the sensor body 3 is bonded to the circuit board 4 in such a state that the reference surface 3a is inclined at an angle θ, for example, in the counterclockwise direction. Then, as shown in FIG. 3, on the upper surface of the base portion 9 of the holding member 8, a pair of compression springs 12 and 13 positioned laterally by a distance f from the center line L1 between the groove portions 10a and 11a, respectively, and then, Both ends of the circuit board 4 are inserted into the groove portions 10a and 11a of the holding member 8 and
As shown in FIG. 2, both side portions of one end of the circuit board 4 are brought into contact with the compression springs 12 and 13, respectively,
The reference surface 14a of the reference block 14 is brought into contact with the reference surface 3a of the sensor body 3. At this time, the reference surface 3a of the sensor body 3 with respect to the reference surface 14a parallel to the reference surface of the holding member 8
a is inclined, for example, counterclockwise by an angle Δθ. Next, the reference surface 14a of the reference block 14 is pushed down by a predetermined dimension to press the reference surface 3a of the sensor body 3 against the spring force of the compression springs 12 and 13 toward the bottom surfaces of the grooves 10a and 11a. With this pressing, the magnetic sensor 2, that is, the sensor body 3 and the circuit board 4 rotate with respect to the holding member 8, and the relative position of the sensor body 3 with respect to the base 9 of the holding member 8 is set. In this state, the circuit board 4 is adhered and fixed to the holding member 8.

Next, the principle of such azimuth adjustment will be described. First, as shown in FIG. 3, let us assume that the reference surface 3a of the sensor body 3 is tilted counterclockwise by an angle Δθ with respect to the reference surface 14a, and in this state it is in a mechanically balanced state. If we come to the conclusion that this state cannot be Δθ> 0, the dynamic equilibrium state is Δθ = 0.
It is proved that it is only when.

In the above-mentioned mechanical equilibrium state, as shown in FIG. 4, the rotational moments in two opposite directions about the fulcrum P at the upper right end of the sensor body 3 are equal. That is, the distance of the straight line PA connecting the fulcrum P and the action point A of the compression spring 12 is D _1, and similarly the distance of the straight line PB connecting the fulcrum P and the action point B of the compression spring 13 is D _2. , B in the direction of rotation are F ₁ and F ₂ , respectively, D _{1
· F 1 = D 2 · F} 2 ...... (1) equation holds. Then, if the inclinations of the straight lines PA and PB with respect to the vertical line are θ ₁ and θ _2, and the forces in the vertical direction at the action points A and B are f ₁ and f ₂ , respectively, then D ₁ · f ₁ · sin θ ₁ = D ₂ · f ₂ ·
sin θ ₂・ ・ ・ Equation (2) can be obtained.

Next, when Δθ ≧ θ and when Δθ <θ
Let's consider it in two ways. However, θ is usually 0 °
Greater than 2 ° and less than 2 °. First, if Δθ ≧ θ,
As shown in FIG. 4, the fulcrum P is located at the upper right end of the sensor body 3.
It is clear that 0 <D₂<D₁... (3) formula is completed
Stand up. In addition, the action points A and B of the compression springs 12 and 13
Displacement amount x₁, X₂Then x₂≤ x₁......
Equation (4) holds. Where Hooke's law, F
= Kx (F: force of compression spring, k: constant peculiar to spring,
x: displacement amount), f₁= K₁・ X₁... (5) formula
And f₂= K₂・ X₂… Equation (6) holds.
One. Then, the constant k unique to the spring₁, K₂Are equivalent
Therefore, from equations (4) to (6), 0 <f₂= K₂・ X₂≤k₁
・ X₁= F₁, That is, 0 <f₂≤ f₁...... Equation (7) holds
stand. From this, the vertical force f at the point of action A
₁Is the vertical force f at the point of action B.₂Equal to or this
Force f₂Can be said to be larger. Also, the fulcrum P is the sensor body
Since it is located at the upper right corner of 3, 0 ° <θ₂<Θ₁<90
The angle θ is larger in the range of 0 ° to 90 °,
sin θ also increases (monotonically increases), 0 <sin θ₂<Sin θ₁
(8) is established, so (3), (7),
From equation (8), D₂・ F ₂・ Sin θ₂<D₁・ F₁・ Sin θ₁You
Nawachi D₂・ F₂<D₁・ F₁...... Equation (9) holds. This
Therefore, the above-mentioned D₁・ F₁= D₂・ F₂…… (1) formula
It cannot be said that Therefore, the state shown in FIG.
In the state, the rotation moment acting on the action point A is large, and the fulcrum
Clockwise until a mechanical equilibrium is reached around P
Rotate to.

On the other hand, when Δθ <θ, 0 <D ₂ <D ₁
Equation (3), 0 <sin θ ₂ <sin θ ₁ (8) is the above Δ
The same holds true when θ ≧ θ. And the circuit board 4
5 is inclined clockwise by an angle (θ−Δθ) as shown in FIG. 5, so that when the displacement amounts of the action points A and B of the compression springs 12 and 13 are x ₁ and x ₂ , respectively, x ₁ <x ₂
...... Equation (10) holds. Therefore, according to Hooke's law, f ₁ = k ₁ · x ₁ <k ₂ · x ₂ = f ₁ (where k ₁ = k ₂ )
...... Equation (11) holds. From this, the left side (D ₁ · f ₁ · sin θ ₁ ) and the right side (D ₂ · f ₂ · sin) of the equation (2) are
When comparing theta ₂₎ and, since the magnitude relationship with each other are mixed, the (2) can not be determined magnitude of the left and right sides of the equation.

Therefore, let's calculate the magnitude relationship using an actual example. That is, in FIG. 5, f = 4 mm and g = 2
Assume that mm and h = 10 mm, and the displacement x ₂ of the compression spring 13 is set to f / 3. Since the angle θ is usually within 2 °, θ−Δθ ≦ 2 °, and from this, 0 ≦ tan (θ−Δθ) ≦ 0.035 (1
Equation 2) holds. Further, as is clear from FIG. 5, x
_{Since 2−} x ₁ = 2f · tan (θ−Δθ), f ₁ −f ₂
= K (x ₂ −x ₁ ) = 2k · f · tan (θ−Δθ) ...
Equation (13) holds. From this equation (13), f ₂ / f ₁ =
1-6 tan (θ−Δθ) is obtained, and if tan (θ−Δθ) is substituted from the relation of the equation (12), f ₂ / f ₁ ≧ 0.7
It becomes 9. Further, D ₂ is the square root of (2 ² +10 ² ), and when this is solved, D ₂ = 10.20. Similarly, D ₁ is θ−
It is the square root of (6 ² +9.72 ² ) when Δθ = 2 °, and when this is solved, D ₁ ≧ 11.42, and θ−Δθ = 0 °
Is the square root of (6 ² +10 ² ), and solving this gives D ₁ ≧
It is 11.66. Therefore, sin θ ₂ = (f−g) / D ₂
= 0.196, sin θ ₁ = (f + g) / D ₁ > 6/11.
66 = 0.515 is required. Therefore, D ₁ · F ₁ / D
₂ · F ₂ = D ₁ · f ₁ · sin θ ₁ / D ₂ · f ₂ · sin θ ₂ = (D ₁
・ Sinθ ₁ / D ₂・ sinθ ₂ ) × (f ₁ / f ₂ ) …… (13)
The formula holds. Substituting the numerical value obtained above into this equation (13), D ₁ · F ₁ / D ₂ · F ₂ = D ₁ · f ₁ · sin θ ₁ / D ₂
・ F ₂ · sin θ ₂ > (11.42 × 0.515) / (1
0.2 * 0.196) * 0.79 = 2.324 is calculated | required. From this, D ₁ · F ₁ > 2.324 × D ₂ · F ₂
> D ₂ · F ₂ and the above D ₁ · F ₁ = D ₂ · F ₂ ......
It can be said that the formula (1) cannot hold. Therefore, FIG.
In the state shown in, the rotational moment acting on the action point A is large, and until the mechanical equilibrium state is reached with the fulcrum P as the center,
Rotate clockwise.

Next, as shown in FIG. 6, when the sensor body 3 is tilted clockwise, the sensor body 3 is rotated counterclockwise about the fulcrum Q at the upper left end of the sensor body 3.

Therefore, from the matters discussed above, the sensor body 3 is in a mechanically equilibrium state at the position where the reference surface 3a including both the fulcrums P and Q contacts the reference surface 14a of the reference block 14. In order to establish the mechanical equilibrium state, the distance 2f between the action points A and B of the compression springs 12 and 13 is larger than the width dimension 2c of the sensor body 3 and is not excessive, and It is necessary that the deformation amounts x ₁ and x ₂ of 12 and 13 be as large as possible within a range in which an excessive force is not applied to the sensor body 3.

In the embodiment thus constructed, the inclination of the sensor main body 3 can be directly adjusted without any relation to the circuit board 4, and for example, the sensor main body 3 is inclined with respect to the circuit board 4. Even if it is fixed by adhesion, the inclination of the sensor body 3 can be adjusted accurately.

In this embodiment, these groove portions 10a,
On the bottom surface of 11a, that is, the top surface of the base portion 9, a compression spring 12,
However, the present invention is not limited to this, and as shown in FIG. 7, a compression spring 2 corresponding to the compression springs 12 and 13 is provided.
1, 22 are mounted on a support 23, and these compression springs 2
1, 2 are inserted through the through holes 24, 25 of the base portion 9 from below, and azimuth adjustment is performed in a state where the respective tips of the compression springs 21, 22 are in contact with both side portions of one end of the circuit board 4, respectively. The compression springs 21, 22 can then be removed from the base 9. Further, a pair of guide pins (not shown) may be attached to the support base 23 so that the guide springs support the compression springs 21 and 22.

[0023]

Since the present invention is configured as described above, it is possible to directly adjust the inclination of the sensor main body without any relation to the circuit board. For example, when the sensor main body is inclined with respect to the circuit board. Even when it is adhesively fixed, the inclination of the sensor body can be accurately adjusted,
Therefore, it is possible to prevent the output value of the detection signal from decreasing and improve the detection accuracy of the magnetic sensor.

[Brief description of drawings]

FIG. 1 is a perspective view showing a magnetic sensor and a holding member of a magnetic rotary encoder in which an embodiment of an azimuth adjusting method of the present invention is used.

2 is a front view of the magnetic sensor of FIG. 1. FIG.

FIG. 3 is a front view of a magnetic sensor and a holding member of FIG.

FIG. 4 is a diagram illustrating a state during azimuth adjustment.

FIG. 5 is a diagram illustrating another state at the time of azimuth adjustment.

FIG. 6 is a diagram illustrating still another state during azimuth adjustment.

FIG. 1 is a perspective view showing an application example of a holding member of a magnetic rotary encoder in which the azimuth adjusting method of the present invention is used.

FIG. 8 is a diagram illustrating a relationship between a magnetic drum and a magnetic sensor.

FIG. 9 is a front view showing a conventional azimuth adjusting device.

[Explanation of symbols]

 2 magnetic sensor 3 sensor body 3a reference surface 4 circuit board 8 holding member 9 bases 10 and 11 protrusions 10a and 11a groove 12 and 13 compression spring 14 reference block 14a reference surface 21 and 22 compression spring 23 support base 24 and 25 through hole

Claims (1)

[Claims] 1. An azimuth of a magnetic rotary encoder for adjusting the azimuth of a magnetic sensor comprising a sensor body facing a magnetic drum having a magnetic pattern in the circumferential direction, and a circuit board to which the sensor body is adhered and held by a holding member. In the adjusting method, first, the sensor body is adhered to the circuit board, then the circuit board is inserted into the groove portion of the holding member, and the lower end of the circuit board is attached to the pair of springs provided on the bottom surface of the groove portion. The both sides are brought into contact with each other, and then the reference surface of the sensor body is pressed against the resilient force of the spring toward the bottom surface of the groove to rotate the sensor body with respect to the holding member. In this state, the circuit board is adhered and fixed to the holding member, and the azimuth adjusting method of the magnetic rotary encoder is characterized.