JP5450512B2 - Thickness detection device and detection roller - Google Patents

Description

  The present invention relates to a thickness detection device that detects the thickness of paper sheets such as banknotes and a detection roller used in the thickness detection device.

  In automatic teller machine (ATM), automatic teller machine (CD), a rotating roller that is driven to rotate to determine the number of banknotes to be deposited or banknotes to be paid, and to determine the denomination and authenticity of banknotes, and a reference The roller outer ring is pressed and connected by an elastic member filled between the outer ring and the rotating shaft, and the detection roller that is driven and rotated, and the paper sheet is conveyed between the reference roller and the detection roller, so that the detection roller outer ring is displaced. A means for detecting irregularities of a medium from a displacement amount detected by a magnetic field displacement sensor is recognized (see Patent Document 1).

  However, this conventional technique has a problem that noise cannot be used as thickness data because noise is generated at the bill end point. There are roughly two types of noise generated at the end points: a medium transport direction and a direction perpendicular thereto. In the direction perpendicular to the transport direction, when only a part of the medium is applied to the detection roller, the detection roller is in a floating state and appears to be displaced more than the medium thickness. For this, a method has been proposed in which the center of gravity of the detection roller is moved in the axial direction to reduce the amount of single float (see Patent Document 2).

  The noise in the medium conveyance direction includes detection roller bounce noise when the medium enters. Due to the impact at the time of entering the medium, the detection roller that should originally follow the thickness of the medium jumps up, and the detection roller displacement becomes unstable. This occurs not only at the end point of the medium but also by foreign matter or irregularities on the medium. Conventionally, countermeasures such as discarding the thickness data of the unstable part of the roller have been taken, which has been a problem of narrowing the thickness detection distribution. In particular, in ATM, a medium is conveyed at a high speed in order to speed up the handling of banknotes. However, as the conveying speed increases, the impact increases, and this problem is expected to increase in the future. In order to maintain or improve the detection speed, it is essential to shorten the time required for the detection roller to follow the medium thickness.

JP 2006-226859 A JP 2006-84274 A

  In the thickness detection apparatus of Patent Document 2, only a part of the banknote is hung on the detection roller, and a detection roller that follows the banknote thickness is provided even when the detection roller is in a single floating state.

  However, the end point in the medium conveyance direction has not been solved yet, because the detection roller does not follow the medium thickness well and cannot be handled as thickness data. In addition, the detection roller jumps due to vibration generated during the conveyance of the medium, resulting in a problem that the thickness detection accuracy is deteriorated. In addition, many clever counterfeit bills have been seen, and more precise authenticity determination has become necessary.

  In view of the circumstances as described above, an object of the present invention is to provide a thickness detection device and a detection roller capable of detecting the thickness of a paper sheet with high accuracy.

In order to solve the above-described problem, a thickness detection device according to one embodiment of the present invention includes a reference roller, a detection roller, and a sensor.
The reference roller has a first rotation axis as a rotation center.
The detection roller is pressed by the reference roller and has a second rotation shaft provided in parallel with the first rotation shaft as a rotation center.
The sensor detects a displacement of the detection roller with respect to the second rotation shaft.
The detection roller has a roller inner peripheral portion fixed to the second rotation shaft, and a roller outer peripheral portion having a cylindrical shape supported by the roller inner peripheral portion,
The inner peripheral portion of the roller is made of an elastic material having a loss tangent tan δ of 0.2 or more and 0.6 or less ,
The roller outer peripheral portion is configured to be displaceable with respect to the second rotation shaft by elastic deformation of the elastic material,
In the elastic material, the organic group is a methyl group, a phenyl group, and a vinyl group, the ratio of the phenyl group to the total organic group is 10 mol% to 50 mol%, and the ratio of the vinyl group is 0.01 mol% to 0.000. A thickness detection apparatus comprising a silicone rubber containing polyorganosiloxane of not more than 08 mol% as a main component .

According to this configuration, when the paper sheet is conveyed between the reference roller and the detection roller, the inner peripheral part of the roller is elastically deformed by the thickness of the paper sheet, and the outer peripheral part of the roller is in relation to the second rotation shaft. Displace. When the sensor detects this displacement, the thickness of the paper sheet is measured. By setting the loss tangent tan δ of the inner peripheral portion of the roller within the above range, it is possible to prevent the roller outer peripheral portion from jumping up when it contacts the paper sheet. Further, even when mechanical vibration occurs during the conveyance of paper sheets, noise due to the vibration is reduced. That is, the thickness of the paper sheet can be detected with high accuracy.
A polyorganosiloxane having a methyl group as an organic group is generally used as a silicone rubber, and a polyorganosiloxane having a methyl group and a phenyl group has an anti-vibration effect. The vinyl group is a crosslinking point, and the loss tangent tanδ varies depending on the content. Specifically, as the vinyl group ratio increases, the number of crosslinking points increases, the hardness increases, and the loss tangent tan δ decreases. That is, it is possible to produce an elastic material having a loss tangent tan δ within the above range by using a silicone rubber containing polyorganosiloxane having an organic group as a main component.
In addition, by setting the ratio of the phenyl group and vinyl group to the organic group within the above range, it is possible to produce an elastic material having a loss tangent tan δ of 0.2 or more and 0.6 or less.

  A plurality of the detection rollers may be arranged in the second rotation axis direction.

  According to this configuration, since the roller outer peripheral portion of each detection roller is independently displaced with respect to the second rotation axis, it is possible to detect the in-plane distribution of the thickness of the paper sheet. This can be used, for example, for detecting a modified ticket having a tape or the like attached to a banknote.

In the elastic material, dry silica having a specific surface area of 100 m ² / g or more and 350 m ² / g or less may be mixed with the polyorganosiloxane.

Dry silica has the effect of increasing the loss tangent tan δ of silicone rubber, and in particular, one having a large specific surface area is effective. On the other hand, if the specific surface area is too large, the silicone rubber becomes sticky and unsuitable for processing. Therefore, the loss tangent tan δ can be adjusted by mixing dry silica having a specific surface area in the above range with the polyorganosiloxane.

  In the elastic material, diphenylsilanediol or dimethylsilanediol may be further mixed with the polyorganosiloxane.

Silane diol improves the compatibility (affinity) of silicone rubber and dry silica. In particular, since the polyorganosiloxane has a methyl group and a phenyl group, dimethylsilanediol and diphenylsilanediol are effective. Therefore, the loss tangent tan δ can be adjusted by mixing diphenylsilanediol or dimethylsilanediol with the polyorganosiloxane.

In order to solve the above-described problem, a detection roller according to an aspect of the present invention includes a reference roller having a first rotation shaft as a rotation center,
A detection roller that is pressed by the reference roller and has a second rotation shaft provided in parallel with the first rotation shaft as a rotation center;
A sensor for detecting displacement of the detection roller relative to the second rotation shaft;
The thickness detection device of the detection roller,
A roller inner periphery fixed to the second rotation shaft and a roller outer periphery having a cylindrical shape supported by the roller inner periphery;
The inner peripheral portion of the roller is made of an elastic material having a loss tangent tan δ of 0.2 or more and 0.6 or less,
The roller outer peripheral portion is configured to be displaceable with respect to the second rotation shaft by elastic deformation of the elastic material,
In the elastic material, the organic group is a methyl group, a phenyl group, and a vinyl group, the ratio of the phenyl group to the total organic group is 10 mol% to 50 mol%, and the ratio of the vinyl group is 0.01 mol% to 0.000. It is a silicone rubber whose main component is polyorganosiloxane of not more than 08 mol%.

  A plurality of the detection rollers may be arranged in the rotation axis direction.

In the elastic material, dry silica having a specific surface area of 100 m ² / g or more and 350 m ² / g or less may be mixed with the polyorganosiloxane.

  In the elastic material, diphenylsilanediol or dimethylsilanediol may be further mixed with the polyorganosiloxane.

  As described above, according to the present invention, it is possible to provide a thickness detection device and a detection roller that can detect the thickness of paper sheets with high accuracy.

The internal block diagram of a banknote conveying apparatus. The internal block diagram of an identification part. The front view which shows the arrangement | positioning relationship between a detection roller and a displacement detection sensor. The principal part front view which shows an example of the displacement state of a detection roller. (A) Structure explanatory drawing of the elastic member with a built-in detection roller. (B) Sectional drawing of the outer ring | wheel of a detection roller and the elastic member to incorporate. (A) Explanatory drawing of the detection roller splash noise at the time of a banknote entering a detection roller and a reference | standard roller in the case of not having a vibration damping mechanism. (B) Explanatory drawing of the detection roller splash noise at the time of having a vibration damping mechanism and a banknote rushes into a detection roller and a reference | standard roller. (C) Comparison explanatory drawing of thickness detection value and banknote thickness. (D) Explanatory drawing of the part which cannot detect banknote thickness. (A) Explanatory drawing of the detection roller splash noise at the time of the foreign material adhering to the banknote in the case of not having a vibration damping mechanism. (B) Explanatory drawing of the detection roller splash noise when the foreign material has adhered to the banknote in the case of having a vibration damping mechanism. (C) Comparison explanatory drawing of thickness detection value and the thickness of the foreign material adhering to the banknote. (D) Explanatory drawing of the part which cannot detect the foreign material thickness adhering to the banknote. Explanatory drawing which shows the experimental result in the Example which verified the effect of this invention. (A) Explanatory drawing of the rubber hardness result of the experimental result which verified the effect of this invention. (B) Explanatory drawing of the attenuation effect result of the experimental result which verified the effect of this invention. (A) The figure which shows the relationship between phenyl group content contained in phenyl silicone, rubber hardness, and loss tangent tan-delta. (B) The figure which shows the relationship between vinyl group content contained in phenyl silicone, rubber hardness, and loss tangent tan-delta. (A) Explanatory drawing which shows the experimental result of the thickness detection value at the time of using the detection roller of loss tangent tan-delta = 0.4 as verification of this invention effect. (B) The figure which shows the experimental result of the thickness detection value at the time of using the detection roller of loss tangent tan-delta = 0.2 as verification of this invention effect. (C) Explanatory drawing which shows the experimental result of the thickness detection value at the time of using the detection roller of loss tangent tan-delta = 0.15 as an example with insufficient damping | damping effect as verification of this invention effect.

  FIG. 1 shows a banknote transport apparatus internally configured in an ATM which is an embodiment of the present invention. In this banknote transport apparatus, 1 is a temporary storage section for temporarily accumulating counted banknotes, and 2 is a denomination of banknotes. , An identification unit for identifying authenticity, orientation, and degree of damage, 3a to 3d are storage units for collecting banknotes by type, 4 is a collection unit for storing banknotes rejected by the identification unit 2, 5 is a deposit port 20, The upper conveying path for conveying the bills by looping the identification section 2, the temporary holding section 1, the withdrawal opening 21 with shutter and the return opening 22, and 6 on the storage sections 3 a to 3 d and the collection section 4 from the upper conveying path 5. A lower conveyance path that conveys banknotes again to the upper conveyance path 5, 7 is a deposit opening conveyance path that conveys banknotes from the deposit port 20 to the upper conveyance path 5, and 8 is a withdrawal with shutter from the upper conveyance path 5. Withdrawal port conveyance path for conveying banknotes to the mouth 21, 9 is the top A return port transport path for transporting banknotes from the transport path 5 to the return port 22, 10 is a temporary storage section storage transport path for transporting banknotes from the upper transport path 5 to the temporary storage section 1, and 11 is an upper section from the temporary storage section 1. Temporary holding unit feeding conveyance path for conveying banknotes to the conveyance path 5, 12a to 12d are storage unit storage conveyance paths for conveying banknotes from the lower conveyance path 6 to the storage units 3a to 3d, and 13a to 13d are storage units 3a to 3d. 3d to the lower conveyance path 6 for storing the banknote feeding conveyance path, 14 for the collection section conveyance path for conveying the banknote from the lower conveyance path 6 to the collection section 4, and 15 for detecting the passage of the banknote. Sensor, 16 is a gate for switching the direction in which banknotes are conveyed, 17 is a deposit port bill detection sensor for detecting whether or not there is a bill in the deposit port 20, and 18 is whether or not there is a bill in the withdrawal port 21 with a shutter. Withdrawal banknote detection sensor to detect, 9 is a return port bill detection sensor for detecting whether there is a bill in the return slot 22.

  FIG. 2 is a schematic diagram showing the main configuration of the identification unit 2. This identification part 2 is provided with the banknote conveyance mechanism 31 identified while conveying the banknote 30 guide | induced here. The banknote transport mechanism 31 is provided with a transport roller section 23 that includes an upper transport roller 23a and a lower transport roller 23b that are installed in the transport path width and face each other vertically. These upper and lower transport rollers 23a and 23b are rotated by a rotational force transmitted from a transport motor (not shown), and a banknote 30 is guided in a horizontally long horizontal state. The banknotes 30 are sandwiched from above and below and transported one by one. To do. Moreover, it has the structure with the high conveyance tolerance which enabled the double feed so that it could convey smoothly also with respect to the damaged banknotes, such as a broken banknote and a cut banknote.

  In the identification unit 2, following the transport roller unit 23, a color linear sensor 24 that checks the transmission amount of the banknote 30 and the transmission amount of the ink, and a magnetic sensor 25 that identifies the magnetism of the magnetic ink applied to the banknote 30. A thickness sensor 26 for detecting the thickness of the bill 30, the presence or absence of a tape, unevenness such as a thread, and an encoder 27 that outputs a clock signal in synchronization with the transport distance of the bill 30 based on the transport drive in the bill transport mechanism 31. And a control unit 28 for determining the denomination, the number of sheets, and the authenticity from the detection data of the thickness sensor 26. Accordingly, the identification unit 2 identifies which denomination is the banknote 30 introduced here, further identifies whether it is a genuine note or a counterfeit, and further, one, two, or three Whether the banknote 30 is the above or not is managed, and the banknote 30 used for the transaction is managed. In addition, the banknote conveyance mechanism 31 is comprised so that it can identify even if the banknote 30 is conveyed from which direction of reciprocation.

  Next, a specific configuration of the thickness sensor 26 provided in the identification unit 2 will be described with reference to FIG. For example, six thickness sensors 26 are arranged at narrow intervals in the same axial direction of the reference roller shaft 37 as a rotation shaft to which a rotational force is transmitted from the conveyance driving system of the bill conveyance mechanism 31. A reference roller 36, six detection rollers 34 a to 34 f disposed on the detection roller shaft 38 so as to face the six reference rollers 36, and these six detection rollers 34 a to 34 f include the reference roller 36. A detection roller group 34 that is pressed against the detection roller 34, a total of twelve displacement detection sensors 33 a to 33 l disposed, for example, two for each of the detection rollers 34 a to 34 f, and each of the displacement detection sensors 33 a to 33 l. A displacement detection sensor group 33 for detecting a roller displacement amount by which the detection rollers 34a to 34f are elastically displaced based on a change in the magnetic field generated from the coil of A sensor processing unit 35 for processing input data from the position detection sensor group 33 are arranged.

  The detection roller shaft 38 is parallel to the reference roller shaft 37, and the relative position of the detection roller shaft 38 is fixed with respect to the reference roller shaft 37. That is, the roller displacement amounts of the detection rollers 34a to 34f are not due to the displacement of the detection roller shaft 38, but are elastic displacement amounts (described later) of the detection rollers 34a to 34f.

  In the present embodiment, six detection rollers 34a to 34f are arranged, and thereby, it is possible to detect the in-plane distribution of the thickness of the banknote. On the other hand, it is also possible to set the number of detection rollers one by one. In this case, the in-plane distribution of the thickness of the banknote cannot be detected, but the thickness of the banknote is reduced when the thickness of the banknote is uniform. It is possible to detect.

  In the above example, six reference rollers 36 are arranged in the conveyance width direction, but a single long roller shaft may be used. FIG. 4 is an explanatory view of a main part showing a part of the thickness sensor 26 in an enlarged manner. Here, for the sake of explanation of the thickness sensor 26, a left detection unit comprising two displacement detection sensors 33a and 33b, a detection roller 34a and a reference roller 36 in the vertical direction, and two displacement detection sensors 33c and 33d in the vertical direction on the right side thereof. A description will be given by taking two sets of the right detection unit including the detection roller 34b and the reference roller 36 as an example.

  The detection rollers 34a, 34b are configured by filling elastically deformable middle rubbers 39a, 39b... Between an outer ring 32a made of a cylindrical member such as metal and a detection roller shaft 38 serving as a central axis thereof. doing. The outer ring 32a can be, for example, SUS304 (stainless steel) plated with hard chrome. In addition to this, an inelastic material can be used as the material of the outer ring 32a. The reference roller 36 is made of metal and is provided as a reference surface whose outer peripheral surface is not displaced, and the detection rollers 34a and 34b are in contact with each other.

  Thus, when the banknote 30 is caught between two sets of roller surfaces of the left and right reference rollers 36 and 36 and the left and right detection rollers 34 a and 34 b, the middle rubbers 39 a and 39 b are deformed by the thickness of the banknote 30. Thus, the outer rings 32a and 32b are displaced upward. The amount of displacement is detected by the two displacement detection sensors 33a and 33b on the left side and the two displacement detection sensors 33c and 33d on the right side, and a detection signal corresponding to the thickness of the banknote 30 is output.

  The detection signal is processed by the sensor processing unit 35 and a digital signal is sent to the control unit 28 for the displacement. In the control unit 28, it is determined from the thickness data of the sent banknote 30 whether two or more banknotes 30 are overlapped and transported, are not a counterfeit ticket with a tape or the like attached, and are not genuine or counterfeit. . Further, by disposing two displacement detection sensors 33a and 33b on both ends of one detection roller 34a so as to face each other, for example, when a tape TA is stuck on the paper surface (see FIG. 4), the tape Since both end portions of the TA are in contact with the left and right detection rollers 34a and 34b and the detection rollers 34a and 34b are unilaterally inclined on the tape TA and tilt in opposite directions, the displacement of the detection rollers 34a and 34b is reduced. Can be detected.

FIG. 5 shows the structure of the middle rubber 39 built in the detection roller 34. FIG. 5A is an external view of the detection roller. The detection roller 34 circumscribes the detection roller rotation shaft 38 and is filled with a middle rubber 39, and the rotation shaft 38 and the middle rubber 39 rotate together. The middle rubber 39 has middle rubber members 42 and 43 composed of two gear-shaped rings, and these are integrally molded to constitute the middle rubber 39 . Further, the metal outer ring 32 is fitted in contact with the middle rubber members 42 and 43 , and the metal outer ring 32 and the middle rubber members 42 and 43 are sandwiched by the retaining ring 41 so that the metal outer ring 32 is not displaced in the axial direction of the detection roller rotating shaft. So that it is fixed. The shapes of the middle rubber members 42 and 43 are not limited to the gear shape, and may be a cylindrical shape.

The elastic material of the middle rubber 39 has a problem that if the rubber hardness becomes too large, the detection roller rotating shaft 38 is bent by a load. In order to avoid this, a rubber hardness (DuroA) of 30 ° Hs or less is desirable. In addition, it is desirable to have a high damping property to attenuate the vibration noise of the detection roller. For this purpose, the loss tangent tan δ of the elastic material constituting the middle rubber 39 is set to 0.2 or more. If the loss tangent tan δ exceeds 0.6, the responsiveness of the detection roller 34 deteriorates due to the sag of the middle rubber 39, so the loss tangent tan δ of the elastic material constituting the middle rubber 39 is set to 0.6 or less. .

  The term “attenuation” as used herein refers to the vibration attenuation of the metal outer ring 32 that is the outer peripheral portion of the detection roller, and a state in which the vibration amplitude is small and the time required for vibration stabilization is short means a state having high attenuation. As to whether or not the vibration is stabilized, it is determined that the vibration is stable when the difference between the vibration peak and the average thickness is 5 μm or less in the detected thickness.

The rubber hardness means a value measured at a temperature of 23 ° C. using a durometer type A (DuroA) conforming to JIS K6253, and the loss tangent tan δ is measured using a dynamic viscoelasticity measuring apparatus conforming to JIS K6394. Means the value to be measured. The loss tangent tan δ is measured under the conditions of an initial load of 100 g, a displacement of 1%, a frequency of 30 Hz, and a temperature of 23 ° C.

As described above, the middle rubber 39 can be made of various elastic materials having a loss tangent tan δ of 0.2 to 0.6. Among these, silicone rubber is particularly preferable because of its high chemical stability, and specifically, silicone rubber mainly composed of polyorganosiloxane having a methyl group, a phenyl group and a vinyl group can be used.

A polyorganosiloxane having a methyl group as an organic group is generally used as a silicone rubber, and a polyorganosiloxane having a methyl group and a phenyl group has an anti-vibration effect. The vinyl group is a crosslinking point, and the loss tangent tanδ varies depending on the content. Specifically, as the vinyl group ratio increases, the number of crosslinking points increases, the hardness increases, and the loss tangent tan δ decreases. An elastic material having a loss tangent tan δ of 0.2 or more and 0.6 or less can be produced by using a silicone rubber containing polyorganosiloxane having an organic group as a main component.

Specifically, in order to produce a silicone rubber containing the above polyorganosiloxane as a main component and having a rubber hardness (DuroA) of 30 ° Hs or less and a loss tangent tan δ of 0.2 or more and 0.6 or less, the following is performed. can do.

  First, the polyorganosiloxane has a phenyl group ratio of 10 mol% to 50 mol% and a vinyl group ratio of 0.01 mol% to 0.08 mol% with respect to all organic groups bonded to silicon. Yes, mix so that the rest is methyl. The proportion of the phenyl group is more preferably 15 mol% or more and 45 mol% or less, and the proportion of the vinyl group is further preferably 0.025 mol% or more and 0.08 mol% or less (see Examples 1 and 2).

Further, dry silica can be mixed with the polyorganosiloxane. Dry silica has the effect of increasing the loss tangent tan δ of silicone rubber, and in particular, one having a large specific surface area is effective. On the other hand, if the specific surface area is too large, the silicone rubber becomes sticky and unsuitable for processing. Therefore, the loss tangent tan δ can be adjusted by mixing the polyorganosiloxane with dry silica having a specific surface area of 100 m ² / g or more and 350 m ² / g or less. The surface area of the dry silica is more preferably from 130 m ² / g to 300 m ² / g (see Example 3).

Furthermore, dimethylsilanediol or diphenylsilanediol can be mixed with the polyorganosiloxane. Silane diol improves the compatibility (affinity) of silicone rubber and dry silica. In particular, since the polyorganosiloxane has a methyl group and a phenyl group, dimethylsilanediol and diphenylsilanediol are effective. Therefore, the loss tangent tan δ can be adjusted by mixing diphenylsilanediol or dimethylsilanediol with the polyorganosiloxane (see Example 4).

The elastic material having the polyorganosiloxane as the base polymer thus produced has a rubber hardness (Duro A) after curing of 5 ° to 30 ° and a loss tangent tan δ of 0.2 to 0.6. It becomes.

Since the middle rubber 39 exhibits a high damping property with a loss tangent tan δ of 0.2 or more, each detection roller 34 has a structure having a vibration damping mechanism. This will be described with reference to FIG. Detection roller 34a, 34b are respectively described Chugo beam 3 9a consisting of, respectively, as can be displaced by being driven by the bill 30 elastic member, and a built-in 39 b. The Chugo arm 3 9a, 39 b shape, material, by the above-described configuration of the filler, can be detected rollers 34a, 34b are built-in vibration damping mechanism, each made of an elastic body, the detection roller and the reference roller The structure has a vibration damping mechanism without being placed outside.

  Next, the difference in noise with and without the vibration damping mechanism will be described with reference to the schematic diagram of FIG. 6A shows the displacement of the detection roller 34 when the medium is transported without the vibration damping mechanism of the present invention, FIG. 6B shows the displacement with the vibration damping mechanism of the present invention, and FIG. 6C. Indicates the actual thickness of the banknote 30. Since the displacement of the detection roller 34 is processed as thickness data by the sensor processing unit 35, the displacement of the detection roller 34 is equal to the thickness data. FIG.6 (d) shows the figure which looked at the banknote 30 from the roller clamping surface. When the medium enters, the detection roller 34 bounces up, and roller bounce noise 70a is generated. The detection roller 34 converges and follows the medium thickness displacement 71 over a period of noise generation time 72a while vibrating.

  As shown in FIG. 6A, the portion where the roller bounce noise 70a is generated appears to have a gently sloping shape at the front end of the medium, and a thickness different from the actual medium thickness 30a is detected. When the vibration mechanism of the present invention is present, the roller bounce noise generation time 72b is shorter than when there is no displacement. At the same transport speed, the shorter the noise generation time, the shorter the length of noise on the detected banknote thickness. Since the portion with noise is not used as thickness data, this is equivalent to the expansion of the thickness detection range.

  When the banknote 30 with the foreign material 74 is conveyed, the displacement of the detection roller 34 when the vibration damping mechanism according to the present invention is provided and when the banknote 30 is provided with the vibration damping mechanism according to the present invention is shown in the schematic diagram of FIG. It explains using. First, the foreign material 74 refers to a material that is not originally included in the banknote 30. Assumed items are tapes, staples, and the like. When the banknote 30 with the foreign material 74 is conveyed, when the vibration damping mechanism is not provided, the displacement of the detection roller is as shown in FIG. The displacement of the detection roller 34 vibrates in the same way as when the banknote 30 enters, and roller bounce noise 70c is generated, and the vibration is converged over a noise generation time 72c.

  The thickness of the foreign matter 74 can be accurately detected only after the detection roller 34 follows the medium thickness after the vibration of the detection roller 34 has converged. When each of the metal outer rings of the detection roller of the present invention has a vibration damping mechanism, the roller splash noise generation time 72d is shortened as shown in FIG. 7B, and the thickness of the foreign matter 74 shown in FIG. The detection roller 34 is driven in a short time. The range in which the thickness data of the shaded portion in FIG. 7D has to be discarded becomes smaller when the vibration damping mechanism is provided.

  In this embodiment, an eddy current magnetic field displacement sensor is used as the displacement detection sensor 33 for detecting the displacement of the detection roller 34 as thickness data. A magnetic field is applied to the detection roller 34 in advance, and the displacement of the magnetic field when the detection roller metal outer ring 32 is displaced is detected as read thickness data. An element that can detect the displacement of the magnetic field may be an MR (magnetoresistance) element or an MI (magnetic impedance) element.

  Hereinafter, based on an Example, the result of having examined the effectiveness of this invention is described. FIG. 8 compares the characteristics at each composition ratio of Experimental Examples 1 to 9 and Comparative Example 1 of the elastic member made of the phenyl group-containing silicone rubber composition and Comparative Example 2 including the elastic member made of the dimethyl silicone composition. Shown as possible. In FIG. 8, Experimental Example 1 shows the actual −1 etc., and Comparative Example 1 shows the ratio −1 etc.

  In addition, the silicone rubber composition in each example shown below includes, for example, a predetermined amount of phenyl group and vinyl group-containing silicone raw rubber as a main component, and a wetter (diphenylsilanediol) containing a predetermined amount of phenyl group or methyl group. Alternatively, dimethylsilanediol) and a predetermined amount of dry silica were kneaded. Regarding the production of such a silicone rubber composition, for example, a heat resistance improver, a colorant and the like are appropriately mixed in addition to the above main components, but only the main components are shown in FIG.

Example 1
In Experimental Examples 1 and 2 and Comparative Example 1, 30 parts by mass of dry silica having a specific surface area of 300 m ² / g and 10 parts by mass of diphenylsilanediol are blended with 100 parts by mass of the phenyl group-containing silicone raw rubber. In this blending, the proportion of phenyl groups was 40 mol%, the proportion of vinyl groups was 0.025 mol% in Experimental Example 1 and 0.025 mol% in Experimental Example 2 with respect to all organic groups bonded to silicon of the phenyl group-containing silicone raw rubber. They were produced using a content of 05 mol% and in the comparative example, a content of 0.10%, and their characteristics were examined.

As the proportion of vinyl groups increases, the hardness increases and the loss tangent tan δ decreases, so the damping effect also decreases. The characteristics of the elastic member made of the silicone rubber composition of Comparative Example 1 are as shown in FIG. It was confirmed that the rubber hardness was 40 °, exceeding the rubber hardness 30 °, and the loss tangent tan δ was 0.15, less than 0.2. Moreover, when the vinyl group was 0.01 mol%, it was impossible to remove from the mold, and the molded product was not realized. As described above, it was found from Example 1 that a favorable result can be obtained if the proportion of vinyl groups is at most 0.05 mol% or less and at least 0.025 mol% or more.
(Example 2)

  Similarly, in Experimental Examples 2, 3, and 4, the proportions of vinyl groups were 0.05 mol% in the formulation of Experimental Example 2, and the proportions of phenyl groups were changed, and the rubber characteristics were confirmed. The proportions of phenyl groups were 40 mol% in Experimental Example 2, 30 mol% in Experimental Example 3, and 15% in Experimental Example 4. Further, Comparative Example 2 was obtained by replacing the phenyl group-containing silicone raw rubber with dimethyl silicone raw rubber in the formulation of Experimental Example 2.

As shown in FIG. 8, as the amount of phenyl groups increases, the rubber hardness increases and the loss tangent tan δ increases. Therefore, in the same composition, the phenyl group-containing silicone raw rubber has a higher damping effect than the dimethyl silicone raw rubber. becomes, and Comparative example 2, the loss tangent tanδ of 0.12, it was confirmed that below the loss tangent Tanderuta0.2. As described above, from Example 2, it was found that a preferable result was obtained when the proportion of the phenyl group was at least 15 mol% or more and at most 40 mol% or less.

(Example 3)
In the blending example of Experimental Example 1, only the specific surface area of dry silica was changed. In Experimental Example 7, a filler having a specific surface area of 200 m ² / g and in Experimental Example 8 was blended with a specific surface area of 130 m ² / g. As shown in FIG. 8, as the specific surface area increases, the friction between the dry silica and the polymer increases. Therefore, the loss tangent tan δ increases, and even when the specific surface area is 130 m ² / g, the loss tangent tan δ is 0.33, 0.2. It was confirmed that it exceeded. Further, when the specific surface area was 380 m ² / g, the stickiness at the time of production was so bad that it was not suitable for processing. As described above, from Example 3, a preferable result can be obtained if the specific surface area of dry silica is at least 130 m ² / g or more. From the viewpoint of workability, 350 m ² / g or less is desirable, and 300 m ² / g or less. Was found to be more desirable.

Example 4
In the blending example of Experimental Example 1, the blending amount of dry silica and the blending amounts of diphenylsilanediol and dimethylsilanediol were changed. In Experimental Example 5, the specific surface area was 300 m ² / g with respect to 100 parts by mass of the phenyl group-containing silicone raw rubber. 15 parts by mass of dry silica and 5 parts by mass of diphenylsilanediol were blended. In Experimental Example 6, it was produced without mixing dry silica and diphenylsilanediol. In Experimental Example 9, 30 parts by mass of dry silica having a specific surface area of 300 m ² / g and 10 parts by mass of dimethylsilanediol were blended with 100 parts by mass of the phenyl group-containing silicone raw rubber. Furthermore, in Comparative Example 3, 60 parts by mass of dry silica having a specific surface area of 300 m ² / g and 20 parts by mass of diphenylsilanediol were blended with 100 parts by mass of the phenyl group-containing silicone raw rubber.

As shown in FIG. 8, the rubber hardness and the loss tangent tan δ both decrease as the blending amount of dry silica and diphenylsilane diol decreases. In Experimental Example 5, the loss tangent tan δ is 0.25, and in Experimental Example 6, the loss tangent tan δ is It was confirmed that the loss tangent tan δ was 0.2 or more. Further, as shown in Experimental Example 9, it was confirmed that even when dimethylsilanediol was added instead of diphenylsilanediol, the loss tangent tan δ was 0.28 and the loss tangent tan δ was 0.2 or more. In Comparative Example 3, it was confirmed that the rubber hardness was 55 ° and exceeded the rubber hardness of 30 °.

  As described above, it was found from Example 4 that it is unsuitable if the amount of dry silica is too large, and that suitable results are obtained in the range of at most 30 parts by mass and at least 15 parts by mass. In addition, it was found that the addition of diphenylsilane diol or dimethyl silane diol gives a suitable result, but if it is too much, it becomes unsuitable, and it has been found that a preferable result is obtained at about 1 part by mass or more and about 10 parts by mass.

9 and 10 show graphs in which experimental examples are arranged. FIG. 9A is a graph in which experimental examples are arranged in order of loss tangent tan δ, and FIG. 9B is a graph in which experimental examples are arranged in order of rubber hardness. Further, FIG. 10A is a graph showing changes in rubber hardness and loss tangent tan δ depending on the phenyl group content by changing only the ratio of phenyl groups contained in phenyl silicone in the blending conditions. FIG. 10B is a graph showing changes in the rubber hardness and loss tangent tan δ depending on the vinyl group content by changing only the ratio of vinyl groups contained in phenyl silicone in the blending conditions.

From these results, for the silicone rubber forming the elastic member built in the detection roller for the thickness detection device, the blending conditions were such that the rubber hardness was 30 ° or less and the loss tangent tan δ was 0.2 or more. A polyorganosiloxane which is a group, a phenyl group and a vinyl group, the ratio of the phenyl group to the total organic group is 10 mol% to 50 mol%, and the ratio of the vinyl group is 0.01 mol%. More than 0.08 mol%, mixing dry silica with a specific surface area of 100 m ² / g to 350 m ² / g to polyorganosiloxane, and mixing diphenylsilanediol or dimethylsilanediol with polyorganosiloxane Determine.

In addition, among the blending conditions in which the rubber hardness is 30 ° or less under such blending conditions, the blending of Experimental Example 1 having the largest loss tangent tan δ is 0.4 is set as the optimum condition. FIG. 11 shows the result of detecting the thickness by conveying a medium having a thickness of 100 μm in the thickness detection apparatus based on the present embodiment. The pressing amount of the detection roller 34 against the reference roller 36 was 0.2 mm, and the medium entry speed was 1600 mm / sec.

  FIG. 11 (a) shows the experimental result using the elastic member of the thickness detection device under the optimum conditions, FIG. 11 (b) shows the experimental result using the elastic member manufactured by the blending of Experimental Example 6, and FIG. 11 (c) shows the result. It is an experimental result using the elastic member manufactured by the mixing | blending of the comparative example 1. FIG. The vertical axis of the graph is the thickness detection value, and the horizontal axis is the medium thickness detection distance.

  Immediately after the medium enters the detection roller and the reference roller and starts detecting the medium thickness, the thickness detection value is larger than the actual medium thickness. This is vibration noise. This vibration noise is compared with the optimum condition in Comparative Example 1. Under the optimum conditions, both the vibration noise amplitude and the medium thickness detection distance (vibration noise generation time) can be reduced, the vibration noise amplitude is reduced by about 69%, and the medium thickness detection distance (vibration noise generation time) is reduced by about 75%. It was.

  The vibration noise is compared in Experimental Example 6 and Comparative Example 1. The vibration noise amplitude was reduced by about 38%, and the medium thickness detection distance (vibration noise generation time) was reduced by about 61%. From the above results, it was confirmed that the detection roller according to the present example is effective for reducing vibration noise when the medium enters the thickness detection apparatus.

Thus, even in the case of Experimental Example 6 ( loss tangent tan δ = 0.2), the medium thickness detection distance (vibration noise generation time) is reduced by about 61% compared to Comparative Example 1, In the present invention, the loss tangent tan δ is defined to be 0.2 or more mainly from the viewpoint of shortening the medium thickness detection distance (vibration noise occurrence time).

DESCRIPTION OF SYMBOLS 2 ... Identification part 26 ... Thickness sensor 27 ... Encoder 28 ... Control part 30 ... Banknote 32 ... Detection roller metal outer ring 33 ... Displacement detection sensor 34 ... Detection roller 35 ... Sensor processing unit 36: reference roller 37 ... reference roller rotation shaft 38 ... detection roller rotation shaft 39 ... middle rubber 41 ... detection roller retaining ring 70 ... detection roller bounce noise 71 .. bill thickness detection value 72 ... detection roller bounce noise generation time 73 ... foreign material thickness detection value 74 ... foreign material

Claims (8)

A reference roller having a first rotation axis as a rotation center;
A detection roller that is pressed by the reference roller and has a second rotation shaft provided in parallel with the first rotation shaft as a rotation center;
A sensor for detecting a displacement of the detection roller with respect to the second rotation shaft;
A thickness detecting device having
The detection roller has a roller inner peripheral portion fixed to the second rotating shaft and a roller outer peripheral portion having a cylindrical shape supported by the roller inner peripheral portion,
The inner peripheral portion of the roller is made of an elastic material having a loss tangent tan δ of 0.2 or more and 0.6 or less ,
The roller outer peripheral portion is configured to be displaceable with respect to the second rotation shaft by elastic deformation of the elastic material,
In the elastic material, the organic group is a methyl group, a phenyl group, and a vinyl group, the ratio of the phenyl group to the total organic group is 10 mol% to 50 mol%, and the ratio of the vinyl group is 0.01 mol% to 0.000. A thickness detection apparatus comprising a silicone rubber containing polyorganosiloxane of not more than 08 mol% as a main component . The thickness detection device according to claim 1,
A thickness detection apparatus, wherein a plurality of the detection rollers are arranged in the second rotation axis direction. The thickness detection device according to claim 1 ,
The elastic material is a thickness detecting device, wherein the polyorganosiloxane is mixed with dry silica having a specific surface area of 100 m ² / g or more and 350 m ² / g or less. The thickness detection device according to claim 3 ,
The thickness detection apparatus according to claim 1, wherein the elastic material is further mixed with diphenylsilanediol or dimethylsilanediol in the polyorganosiloxane. A reference roller having a first rotation axis as a rotation center ;
A detection roller that is pressed by the reference roller and has a second rotation shaft provided in parallel with the first rotation shaft as a rotation center;
A sensor for detecting displacement of the detection roller relative to the second rotation shaft;
The thickness detection device of the detection roller,
A roller inner periphery fixed to the second rotation shaft and a roller outer periphery having a cylindrical shape supported by the roller inner periphery;
The inner peripheral portion of the roller is made of an elastic material having a loss tangent tan δ of 0.2 or more and 0.6 or less ,
The roller outer peripheral portion is configured to be displaceable with respect to the second rotation shaft by elastic deformation of the elastic material,
In the elastic material, the organic group is a methyl group, a phenyl group, and a vinyl group, the ratio of the phenyl group to the total organic group is 10 mol% to 50 mol%, and the ratio of the vinyl group is 0.01 mol% to 0.000. A detection roller, which is a silicone rubber mainly composed of polyorganosiloxane of not more than 08 mol% . The detection roller according to claim 5 , wherein a plurality of the detection rollers are arranged in the rotation axis direction. The detection roller according to claim 5 ,
The detection roller, wherein the elastic material is a mixture of the polyorganosiloxane and dry silica having a specific surface area of 100 m ² / g to 350 m ² / g. The detection roller according to claim 7 ,
The detection roller, wherein the elastic material is further mixed with diphenylsilanediol or dimethylsilanediol in the polyorganosiloxane.

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