JP2011047787A - Object detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detector that is excellent in detection accuracy and resolution and is capable of attaining size reduction, at low cost. <P>SOLUTION: A detector, which detects a thickness of an object or a traveling amount in a constant direction based on a datum face, includes a lever portion 1, one end of which is supported by a rotating shaft 3 and the other end of which has the datum face or a curved surface capable of abutting on an object and which oscillates with the abutment of the object, and a displacement transmission portion 2 which is supported by the rotating shaft 3 and is displaceable with the oscillation of the lever portion 1. The curved surface is machined to abut on the object at a point which substantially meets on one straight line V orthogonal to the datum face during the oscillation with the abutment of the object in an estimated range. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an apparatus for detecting the thickness of an object or the amount of movement in a certain direction.

  In machines such as printing presses, scanners, automatic ticket gates, vending machines, ATMs, etc., the thickness or the amount of movement in a certain direction of objects to be handled such as paper, tickets, banknotes, etc. can be detected during the supply or discharge process. Requested.

  This type of detection device includes an upper and lower roller disposed facing a paper supply path, an LED and a PSD, a lever instead of the LED and PSD, and a reflector attached to the rear end of the lever. And a photosensor that emits light toward the reflector and receives the reflected light is known (Patent Document 1 [Prior Art] column). As shown in FIG. 16, the former is normally urged by the spring 103 in the direction in which the upper roller 101 approaches the lower roller 102, and is moved upward by the thickness of the paper against the restoring force of the spring 103 when the paper passes. The roller 101 moves away from the lower roller 102, and the displacement amount of the upper roller 101 is optically detected by the LED and PSD. In the latter case, as shown in FIG. 17, the lever 104 is swingably fixed to a fulcrum, and the tip of the lever 104 is connected to the shaft of the upper roller 101. Is urged in a direction to approach the lower roller 102, and the photo sensor 105 detects the amount of displacement of the rear end of the lever 104 that swings as the paper passes.

  Further, by improving this, as shown in FIG. 18, the rear end of the lever 104 is branched into a plurality of branches 106, or the rear end of the lever is fan-shaped to provide a radial slit so that the light of the photo interrupter passes. A device that detects the number of branches and slits is also known (Patent Document 1 [Embodiment]). In order to detect a minute change in the object in either the apparatus of FIG. 17 or the apparatus of FIG. 18, the ratio b of the length b from the fulcrum to the rear end of the lever and the length a from the fulcrum to the lever tip is b. It is necessary to increase / a. In order to increase this ratio, either b is increased or a is decreased. In order to achieve a reduction in the size of the apparatus, it is desired to decrease a.

JP2003-294401A

However, since the PSD of FIG. 16 is expensive and the upper roller needs to be processed with high accuracy so as not to warp, the manufacturing cost is extremely high. On the other hand, in the apparatus shown in FIG. 17 and the apparatus shown in FIG. 18, if a is made small in order to achieve miniaturization of the apparatus, the circumferential component of the displacement amount at the lever tip becomes larger than the vertical component originally desired to be detected. This hinders an increase in the detection accuracy by increasing the ratio b / a.
Therefore, an object of the present invention is to provide a detection device that is excellent in detection accuracy and can be miniaturized at low cost.

In order to solve the above-described problem, the detection device of the present invention provides:
An apparatus for detecting the thickness of an object or the amount of movement in a certain direction based on a reference plane,
A lever portion having one end supported by the rotation axis C and having a curved surface capable of coming into contact with a reference surface or an object at the other end, and swinging with the contact of the object;
In what is provided with the displacement amount transmission part supported by the rotating shaft C and displaceable according to the swing of the lever part,
The curved surface is processed so as to abut on the object at a point that substantially coincides with one straight line V orthogonal to the reference surface while the curved surface swings with the abutment of the object within the assumed range. And

  FIG. 1 is a diagram showing the operation of the detection device of the present invention. Assume that the highest position of the lever portion 1 is lowered by Δt by being pushed by the supplied paper from the time when there is no paper and the highest position of the lever portion 1 is in contact with the reference surface (the position of the solid line in the figure). (Position of broken line in the figure). The length from the highest position of the lever part 1 to the center of the rotating shaft 3 is L, the angle of the lever part 1 with respect to the horizontal at that time is θ, and the light of the scale part 2 that is the displacement amount transmitting part from the center of the rotating shaft 3 The length to the center of the axis is J, and the minute displacement amount of the scale portion 2 accompanying the displacement of the lever portion 1 is Δd. By designing so that the highest position of the lever portion 1 always exists on one perpendicular line V orthogonal to the reference plane, L: Δt / cos θ = J: Δd and Δt = Δd (1 / J) Lcos θ is derived. The length from the highest position of the lever portion 1 to the center of the rotary shaft 3 and the angle of the lever portion 1 with respect to the horizontal are both variables, but cos θ increases with a decrease in L as the highest position of the lever portion 1 decreases. So they cancel each other out. Therefore, (1 / J) L cos θ maintains a substantially constant value. As a result, Δt and Δd are proportional.

  One basic machined so that the curved surface abuts on the object at a point that substantially coincides with one straight line V orthogonal to the reference surface while the curved surface swings as the object abuts within the assumed range. A typical configuration is as follows. That is, as shown in FIG. 2, the contact point where the lever part contacts the reference surface is P, the contact point that contacts the specific object having the maximum thickness or the maximum movement amount as the assumed detection limit, and the reference point where the contact point contacts the contact point P. When the point on the surface is S, and the curvature radii of the curved surface at the contacts P and Q are Rp and Rq, respectively, the contact P when contacting the reference surface and the contact when contacting the specific object The curved surface is processed so that the curvature centers Op and Oq of the curved surface at Q are located on the straight line V and Rp is not smaller than Rq.

  In this way, by forming a curved surface composed of a plurality of arcs having different curvature radii depending on the contact point, the lever portion is always positioned at the highest point on the substantially straight line V. For the curved surface between the contacts PQ, for example, the arcs of radius Rq and Rp at the contacts P and Q may be directly connected, or may be connected by an arc having a radius between Rq and Rp. Alternatively, it is composed of a plurality of minute arcs whose radius of curvature decreases as it approaches the contact point Q between Rq and Rp, and on the straight line V that moves away from the reference plane as these fine arcs approach a fixed position on the straight line V or the contact point Q. You may make it have a curvature center in a position. The positions of the curvature centers Op and Oq may or may not coincide.

  While the curved surface oscillates with the contact of the object within the assumed range, the curved surface is processed so as to contact the object at a point that substantially coincides with one straight line V orthogonal to the reference surface. As shown in FIG. 3, the basic configuration is that the maximum thickness or the maximum movement amount of the specific object is w, and the angle formed between the lever portion and the reference surface when the contact P is in contact with the reference surface is θ. When the length from the center of the rotation axis C to the contact point P is L, the curved surface has a center of curvature on the straight line V, and Rm = Lsin θ−nw (n = 0.3 ± 0.1) Is composed of a single arc having a radius of curvature that satisfies This is because, when simulation is performed under various conditions, Δt and Δd have the most proportional relationship within a range that satisfies the above formula.

  As described above, according to the detection device of the present invention, Δt and Δd are proportional regardless of the length of the lever portion. Therefore, the detection accuracy can be improved and the size can be reduced simultaneously by shortening the length of the lever portion. be able to.

It is a figure which shows the effect | action of the detection apparatus of this invention. It is a figure which shows one basic composition of the detection apparatus of this invention. It is a figure which shows another basic structure of the detection apparatus of this invention. It is sectional drawing which shows the detection apparatus of Embodiment 1. It is a front view which shows the scale integrated lever applied to the detection apparatus. It is XX sectional drawing of FIG. (A) is a figure which shows the design method of the lever part used for the detection apparatus of Embodiment 1, (b) is the enlarged view. It is a figure which shows the design method of the lever part used for the detection apparatus of Embodiment 2. It is a figure which shows the design method of the lever part used for the detection apparatus of Embodiment 3. It is a figure which shows the track | orbit of the curved surface between the contact points PQ in Embodiment 4 about various curvature radii. It is a graph which shows the result of having simulated the value of the minute displacement (DELTA) t of the lever part with respect to the minute displacement (DELTA) d of a scale part by making a curvature radius into a parameter. It is a graph which shows the result of having simulated the value of the minute displacement (DELTA) t of the lever part with respect to the minute displacement (DELTA) d of a scale part using (theta) as a parameter. It is another graph which shows the result of having simulated the value of the minute displacement (DELTA) t of the lever part with respect to the minute displacement (DELTA) d of a scale part using (theta) as a parameter. FIG. 10 is a front view illustrating a detection device according to a fifth embodiment. It is a front view which shows the detection apparatus of Embodiment 6. It is sectional drawing which shows the conventional detection apparatus. It is sectional drawing which shows another conventional detection apparatus. It is sectional drawing which shows another conventional detection apparatus.

Embodiment 1
Hereinafter, the present invention will be specifically described based on embodiments. FIG. 4 is a vertical sectional view parallel to the rotation axis of the detection device of the first embodiment, and FIG. 5 is a front view showing a scale-integrated lever applied to the detection device.

The detection device 11 is a device that detects the thickness of the paper, and includes a holder 12, a light receiving element 13, a collimating lens 14, a light emitting element 15, and a scale-integrated lever 10.
The scale-integrated lever 10 is entirely made of a light-transmitting resin. As shown in FIG. 5, the lever portion 16, the scale portion 17, the rotating shaft 18 and the stopper 19 are about 1.3 mm thick except for the rotating shaft 18 portion. It is integrally formed into a plate shape. The outline of the scale-integrated lever 10 includes two sides a and b that are orthogonal to each other when viewed from the front, a side c that is parallel to one side a and shorter than the side a, and an angle that connects side a and side c. It forms a substantially trapezoid consisting of the side d. The lever portion 16 is formed so as to extend substantially along the side d at the corner where the side a and the side d intersect, and the stopper 19 so as to extend along the side c at the corner where the side b and the side c intersect. Is formed. The peripheral surface of the lever portion 16 is smoothly bent so as to move away from the extension line of the side d and approach the side b as it goes toward the tip, and forms a contact point with the paper to be detected. The shape of this curved surface will be described later.

  The rotating shaft 18 has a columnar shape protruding at an intermediate portion of the side d so as to be orthogonal to both surfaces of the plate-like portion. Accordingly, the lever portion 16 and the stopper 19 are substantially diagonal to each other with the rotation shaft 18 therebetween. Further, in the vicinity of the corner where side a and side b intersect, a scale portion 17 formed of a large number of light-shielding regions and light-transmitting regions arranged alternately at equal intervals in the circumferential direction around the rotation axis 18 is formed. Has been. As a means for providing the scale portion 17, as shown in FIG. 6 as an XX sectional view of FIG. 5, a horizontal smooth surface and a light shielding region 17b as a light transmitting region 17a formed on one main surface of the plate-like portion. A prism composed of a non-horizontal smooth surface (FIGS. 6A and 6B) may be used, or a light shielding material is printed or roughened next to the horizontal smooth surface as the light-transmitting region 17a. However, the light shielding region 17b (FIG. 6C) may be used.

  The rotary shaft 18 is supported by a bearing portion at the upper end of the holder 12 so that the lever portion 16 is on the upper side and the scale portion 17 is on the lower side. A coil spring 5 is attached to the outer peripheral surface of the rotary shaft 18 to exert a restoring force in a direction in which the lever portion 16 is urged upward. The restoring force is suppressed by engaging the stopper 19 with the holder 12, and the line connecting the contact point of the lever portion 16 and the rotary shaft 18 is kept at an inclination of approximately 30 degrees with respect to the horizontal. ing. The translucent area 17a or the light-shielding area 17b at both ends of the scale portion 17 is at a position rotated by 100 to 150 degrees from this line.

  The curved surface constituting the contact point with the paper in the lever portion 16 is processed as follows. That is, as shown in FIG. 7A, the contact point at which the lever portion contacts the reference surface is P, the contact point that contacts the specific object K having the maximum thickness or the maximum movement amount as the assumed detection limit is Q, and the contact point P Let S be the point on the reference surface that makes contact with S, W be the maximum thickness or maximum movement amount of the specific object K, and Rp and Rq be the radius of curvature of the curved surface at the contacts P and Q, respectively. At this time, in the vicinity of the contacts P and Q, the curvature centers Op and Oq of the curved surface at the contact P when contacting the reference surface and the contact Q when contacting the specific object are both described above. It is located on the straight line V and processed so that Rp = Rq + 0.5w.

  The curved surface between the contact points PQ may be connected by, for example, an arc having a radius between Rq and Rp, or may be Rq or more and Rp or less as shown in FIG. 7 (b) as an enlarged view of FIG. 7 (a). On the straight line V, the radius of curvature decreases as the distance from the contact point Q decreases (three in the figure), and the fine arcs move away from the reference plane as they approach the fixed position on the straight line V or the contact point Q. The positions Oa, Ob, Oc... May have a center of curvature. In this way, by forming a curved surface composed of a plurality of arcs having different curvature radii depending on the contact point, the lever portion is always positioned at the highest point on the substantially straight line V. As a result, the thickness or movement amount Δt of the object is proportional to the displacement amount Δd of the scale portion 17, and the detection accuracy is excellent. This proportional relationship does not depend much on the length of the lever portion 16, and the lever portion 16 and the scale portion 17 form an angle other than 180 ° with the rotation shaft 18 as the center. Thus, the overall size of the apparatus can be reduced.

Embodiment 2
The curved surface between the contact points PQ in the first embodiment has a curvature center Op (= Oq) on the straight line V, a circular arc of radius Rp passing through the contact point P, and a radius Rq passing through the contact point Q (= Rp-0. The lever portion 16 was designed as the same configuration as in the first embodiment except that it was formed by two arcs composed of 5w) arcs, and the operation thereof was simulated. FIG. 8 is a diagram showing a curved surface design method and trajectory between the contacts PQ. Incidentally, both side portions between the contacts PQ are formed by a micro arc having a radius of curvature Rp extending from the contact P in a direction away from the contact Q and a micro arc having a radius of curvature Rq extending from the contact Q in a direction away from the contact P, respectively. ing.

  As shown in FIG. 8, when the object is not present and the lever portion 16 is raised, the contact P is the highest on the straight line V, while the object having the thickness w is present and the lever portion 16 is When descending, the contact Q is at the highest position on the straight line V. As a result, Δt and Δd are proportional to each other as in the first embodiment, so that the detection accuracy is excellent and the size of the entire apparatus can be reduced. Further, since both side portions between the contact points PQ are formed by a predetermined minute arc connected between the contact points PQ, the mounting position of the rotating shaft 18 is slightly different, or the thickness of the object is slightly over w. Even in such a case, the proportional relationship between Δt and Δd is established.

Embodiment 3
In the first embodiment, the curved surface between the contact points PQ has a curvature center Op (= Oq = Od = Oe) on the straight line V, a circular arc of radius Rp passing through the contact point P, and a radius Rq passing through the contact point Q (= Rp-0.75w), a radius Rd (= Rp-0.25w) connecting the two arcs, and a circle having a radius Re (= Rp-0.50w), a total of four arcs. Except for the above, the lever portion 16 was designed as the same configuration as in the first embodiment, and the operation was simulated. FIG. 9 is a diagram showing a curved surface design method and track between the contact points PQ. Regardless of the angle of the lever portion 16, the position of the highest point of the lever portion 16 becomes closer to the straight line V, and the detection accuracy is further superior to that of the second embodiment.
On the contrary, in order to simplify the design, the detection accuracy is slightly inferior to that of the second embodiment, but the curved surface between the contacts PQ is represented by Rm = Rp-nW (n = 0.3 ± 0.1). May be formed by a single arc of radius Rm that satisfies

Embodiment 4
In the first embodiment, the curved surface between the contact points PQ is formed by a single arc having a center of curvature on the straight line V and a radius of curvature of Rm = Lsin θ−nw (n = 0.3 ± 0.1). Except for this, the operation of the lever portion 16 was simulated as the same configuration as in the first embodiment. Here, w is the maximum thickness of the paper, θ is the angle formed by the lever portion and the reference surface when the contact P is in contact with the reference surface, and L is the length from the center of the rotation axis C to the contact P. is there. For comparison, a simulation was also performed under conditions where Rm did not belong to the above range.

  FIG. 10 shows the trajectory of the curved surface for various Rm when L = 8 mm, w = 2 mm, and θ = 30 °, and Table 1 shows the result of simulating the value of Δt with respect to Δd. Table 2 shows the degree of error of the simulation value with respect to the ideal value where Δd = Δt, and FIG. 11 is a graph of this.

  As shown from the simulation, the deviation from the ideal value is minimized by designing so as to satisfy Rm = Lsinθ−0.3w, and then when Rm = Lsinθ ± 0.5w is small, the allowable range in actual use It becomes.

  Next, Table 3 shows the degree of error of the simulation value with respect to the ideal value where Δd = Δt when the simulation is performed by changing θ when Rm = Lsinθ−0.3w. Is shown in FIG.

As shown in Table 3 and FIG. 12, it is apparent that there is no problem even if θ is different as long as Rm = Lsin θ−0.3w is satisfied.
Next, Table 4 shows the degree of error of the simulation value with respect to an ideal value where Δd = Δt when Rm = Lsin θ−0.3w and simulation is performed by changing θ to w = 4 mm. FIG. 13 shows a graph of the above.

  As shown in Table 4 and FIG. 13, the simulation value greatly deviates from the ideal value at θ = 60 °, and a non-negligible deviation occurs even at θ = 45 °. Therefore, it is preferable to design L or set w so that L ≧ 2w.

-Embodiment 5
In the detection apparatus according to the fifth embodiment, as shown in FIG. 14, the object moving in the vertical direction can be detected by making the angle between the lever portion 16 and the scale portion 17 larger than 180 °. . In this case, it is only necessary to replace the scale integrated lever 10 with that of the first or second embodiment.

-Embodiment 6
As shown in FIG. 15, the detection device of the sixth embodiment has the moving direction of the object substantially coincident with the displacement direction of the lever portion 16 and is suitable for detecting the moving speed of the object.

DESCRIPTION OF SYMBOLS 11 Detection apparatus 12 Holder 13 Light receiving element 14 Lens 15 Light emitting element 10 Scale integrated lever 1,16 Lever part 2,17 Scale part 3,18 Rotating shaft 19 Stopper 5 Coil spring

Claims (8)

An apparatus for detecting the thickness of an object or the amount of movement in a certain direction based on a reference plane,
A lever portion having one end supported by the rotation axis C and having a curved surface capable of coming into contact with a reference surface or an object at the other end, and swinging with the contact of the object;
In what is provided with the displacement amount transmission part supported by the rotating shaft C and displaceable according to the swing of the lever part,
The curved surface is processed so as to abut on the object at a point that substantially coincides with one straight line V orthogonal to the reference surface while the curved surface swings with the abutment of the object within the assumed range. Detection device.   The contact point where the lever part contacts the reference surface is P, the contact point which contacts the specific object having the maximum thickness or the maximum movement amount as the assumed detection limit is Q, the point on the reference surface which contacts the contact point P is S, the contact point When the curvature radii of the curved surface at P and Q are Rp and Rq, respectively, the curvature center Op of the curved surface at the contact P when in contact with the reference surface and the contact Q when in contact with the specific object. And Oq are positioned on the straight line V, and the curved surface is processed so that Rp does not become smaller than Rq.   The curved surface has a contour including a micro arc having a radius of curvature Rp extending from the contact P in a direction away from the contact Q and a micro arc having a radius of curvature Rq extending from the contact Q in a direction away from the contact P. Detection device.   4. The detection device according to claim 2, wherein Rp = Rq + ½w, where w is a maximum thickness or a maximum movement amount of the specific object.   The curved surface between the contact points PQ is composed of a plurality of minute arcs having a radius of curvature that is smaller than or equal to Rq and less than or equal to Rp and decreases in radius of curvature, and the reference surface becomes closer to the fixed position on the line V or the contact point Q The detection device according to claim 2, wherein the detection device has a center of curvature at a position on the straight line V away from the center. ,   6. The detection device according to claim 5, wherein the curved surface between the contact points PQ is a single arc having a radius of curvature Rm that satisfies Rm = Rp-nW (n = 0.3 ± 0.1).   The maximum thickness or the maximum movement amount of the specific object is w, the angle between the lever part and the reference plane when the contact P is in contact with the reference plane is θ, and the length from the center of the rotation axis C to the contact P When the thickness is L, the curved surface has a center of curvature on the straight line V, and has a radius of curvature satisfying Rm = Lsin θ−nw (n = 0.3 ± 0.1). The detection device according to claim 1.   The detection device according to claim 1, wherein the displacement amount transmitting unit is a scale unit that is periodically processed in a circumferential direction.

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