Method for installing a rotation angle detection module on an instrument and angle adjustment template jig used therefor

Abstract

The present invention provides a method for installing a rotation angle detection module onto an instrument and an angle adjustment template jig used therefor, by which attachment to the instrument is possible even while the instrument is in operation, and attachment work can be quickly performed without individual calibration work for rotating an indicator after the attachment.　A magnet is mounted to an indicator collar part for an indicator 120 positioned at an arbitrary angle. At least the detection module is supported around the rotation axis with respect to a scale plate of the instrument having the indicator, so as to allow relative rotation to the scale plate. A marker M2 is aligned with the position of the indicator 120, and an angular coordinate calibration means is operated. The detection module is adjusted and rotated so as to match the marker with a reference angle position and is fixed.

Description

[Technical Field]

[0001] The present invention relates to a method for installing a rotation angle detection module on an instrument and an angle adjustment template jig used therefor. More specifically, the present invention relates to a method for installing a rotation angle detection module on an instrument so that the rotation angle of the pointer can be detected, using a pointer magnet for detecting the rotation angle of the pointer on the instrument using a magnetic sensor, and a detection module for detecting the rotation angle of the pointer based on the relative position of the magnet and the magnetic sensor, and an angle adjustment template jig used therefor. [Background technology]

[0002] A known rotation angle detection module for an instrument is disclosed in Patent Document 1 below. Paragraph 0006 of the document states, "A magnetic clip is provided for attaching the magnet to the pointer of the instrument at a position displaced circumferentially from the central axis of the pointer, and the magnetic sensors are provided at multiple locations around the central axis, and the rotational displacement of the magnet accompanying the rotation of the pointer is determined by the relative position of the magnetic sensors at the multiple locations and output as an electrical signal." The magnet attached at a position displaced from the center is not positioned in the drawing, and machining of the magnetic clip is required, making it virtually impossible to attach to an operating instrument. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-4294 Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the current situation, the present invention aims to provide a method for installing a rotation angle detection module on an instrument that can be attached to the instrument even while the instrument is in operation, and that allows for quick installation without the need for separate calibration work to rotate the pointer after installation, as well as an angle adjustment template jig to be used for this. [Means for solving the problem]

[0005] In order to achieve the above object, the method of installing a rotation angle detection module on an instrument according to the present invention is characterized in that it uses a pointer magnet for detecting the rotation angle of a pointer on the instrument using a magnetic sensor, and a detection module for detecting the rotation angle of the pointer based on the relative position of this magnet and the magnetic sensor, and is installed so that the rotation angle of the pointer can be detected, wherein the magnet has a polarity in a direction perpendicular to the rotation axis of the pointer, and the detection module detects the rotation angle in the direction of magnetic lines of force caused by the relative rotation of the pointer magnet on the magnetic sensor, and the detection module operates an angle coordinate calibration means at a specific angle between the sensor and the magnet to calibrate the specific angle to zero angle, 135 degrees, or other reference angle. the detection module has a marker and / or a marker mounting portion that indicates the reference angular position for matching an angular coordinate related to a rotation angle relative to a scale plate, and the detection module has a magnet mounting step for mounting the magnet to a pointer collar portion of a pointer positioned at an arbitrary angle; a detection module supporting step for supporting at least the detection module so that it can rotate relatively to the scale plate around the rotation axis with respect to the scale plate of an instrument having a pointer; an angular coordinate calibrating step for aligning the marker with the position of the pointer and operating the angular coordinate calibrating means; and a detection module adjusting and rotating step for adjusting and rotating the detection module and fixing it so that the marker matches the reference angular position.

[0006] In the magnet mounting step, the pointer can be positioned anywhere, and the direction of the magnet's magnetic field lines does not matter, as long as the magnet is mounted on the pointer collar. Then, by sequentially performing the detection module support step, angle coordinate calibration step, and detection module adjustment and rotation step, the detection module signal relative to the pointer angle coordinate can be identified and the pointer angle coordinate can be determined. This series of steps can be performed even when the pointer is not at the zero position and is in operation, and the adjustment process can be completed in an extremely short time.

[0007] In the above, the angular coordinate calibration means may be a switch such as a manual button. By pressing the angular coordinate calibration switch, the pointer position and the angular coordinate of the detection module are aligned. Alternatively, the angular coordinate calibration means may be a proximity detection sensor that is closest when the pointer and the marker positions are aligned. This allows the angular coordinate calibration process to be automated, further reducing the effort required for installation.

[0008] The pointer magnet is plate-shaped and has a through-hole that penetrates the plate, and the shaft of the jig is passed through this through-hole and its tip is engaged with the central hole of the pointer collar, so that it is fixed close to the pointer collar. Even while the pointer is moving, the pointer center axis P1 and the magnet center axis P2, which will be described later, can be easily aligned, reducing measurement errors.

[0009] In each of the above methods, the markers may include a first reference marker corresponding to a first reference angular position such as zero degrees, and a second reference marker corresponding to a second reference angular position such as 135 degrees, and one of the first and second reference markers may be used in the angular coordinate calibration step, and the other reference marker may be used in the detection module adjustment / rotation step. This is convenient when it is difficult to match the angular coordinates, for example, because part of the instrument dial is contaminated and indistinguishable.

[0010] The detection module may have the magnetic sensor housed in a cylindrical holder and positioned near the center of a circular transparent cover plate that covers the pointer, and the magnetic sensor can be rotated and fixed together with the transparent cover plate around the central axis relative to the scale plate by holding the outer periphery of the holder with fingers. With this configuration, the holder can be operated with fingers during each of the steps, making it easier to accurately match each coordinate.

[0011] The instrument may also have an outer frame to which the edge of the transparent cover plate can be fixed, the outer diameter of the transparent cover plate being smaller than the inner diameter of the outer frame so that there is a clearance (play) between them, and an angle adjustment template jig having an opening, the holder can be inserted through the opening and attached to the template jig so as not to rotate relative to it, and the template jig may have a center position gauge that aligns the center of the sensor with the outer frame by the relative distance from the outer frame, and an angle scale that serves as the marker for measuring the angle. Such clearance in the outer frame makes it easier to align the pointer center axis P1 and the sensor center axis P3, which will be described later, and contributes to reducing measurement errors.

[0012] The angle adjustment template jig used in this method for installing a rotation angle detection module on an instrument is characterized in that it includes a plate-shaped template body that can be attached by inserting the holding portion so that it cannot rotate relative to the outer frame, and the template body has a center position gauge that aligns the center of the sensor with the outer frame based on the relative distance from the outer frame, and an angle scale for measuring angles. In this case, it is preferable that the center position gauge be a plurality of concentric circles. Using the center position gauge and the angle scale for measuring angles makes it easier to align the pointer center axis P1 and the sensor center axis P3 (described below), and at the same time, it also makes it easier to align each coordinate.

[0013] Here, the template body may include at least two pieces with different outermost diameters, and the maximum diameter of the circle of the large-diameter template body may be larger than the maximum diameter of the circle of the small-diameter template body. Since the scale of a larger-diameter instrument is also farther from the center axis of the pointer on the dial plate, it is desirable to use a template body with a larger maximum diameter. However, when small-diameter instruments are closely spaced, a large-diameter template jig cannot be used, and using a small-diameter template jig will make the adjustment process smoother. [Effects of the Invention]

[0014] According to the features of the method for installing a rotation angle detection module on an instrument and the angle adjustment template jig used therein according to the present invention, the module can be installed on the instrument even while the instrument is in operation, and installation can be carried out quickly without the need for separate calibration work to rotate the pointer after installation.

[0015] Other objects, configurations and effects of the present invention will become apparent from the following detailed description of the preferred embodiments of the present invention. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a cross-sectional view of an instrument or the like to which a module is to be installed, in accordance with a method for installing a rotation angle detection module in an instrument according to the present invention. [Figure 2a] 1 is a perspective view of an instrument etc. in a state where a detection module used in a method for installing a rotation angle detection module in an instrument according to the present invention is attached. [Figure 2b] 2b is a front view of the instrument etc. with the detection module removed from FIG. 2a. FIG. [Figure 2c] FIG. 2b is a front view of the instruments etc. with the magnet removed. [Figure 3a] FIG. 2 is a cross-sectional view of the detection module. [Figure 3b] FIG. 2 is a cross-sectional view of the detection module. [Figure 3c] FIG. 2 is a plan view of the detection module. [Figure 3d] FIG. 2 is a diagram illustrating the principle of a detection module. [Figure 3e] FIG. 2 is a diagram illustrating the principle of a detection module. [Figure 3f] FIG. 2 is a block diagram of a detection module. [Figure 4] 10 is a graph showing the relationship between the output of the detection module and the rotation angle of the magnet. [Figure 5a] FIG. [Figure 5b] FIG. 1 is a diagram illustrating the principle of a magnet rotating jig. [Figure 6] Photographs showing the procedure for attaching a magnet to the pointer collar in the magnet attachment step. [Figure 7a] 10A and 10B show photographs of an angle adjustment template jig and two plan views. [Figure 7b] FIG. 10 is a photograph of an angle adjustment template jig, showing a perspective view from the back side. [Figure 7c] FIG. 10 is a photograph of the angle adjustment template jig, showing a plan view of the jig attached to the outer frame. [Figure 7d] 10 is a photograph of the angle adjustment template jig, and is a plan view showing the step of aligning the first reference marker MB1 with the pointer in the angular coordinate calibration step. FIG. [Figure 7e] FIG. 10 is a photograph of the angle adjustment template jig, showing the state in which the angle coordinate calibration switch is pressed during the angle coordinate calibration process. [Figure 7f] FIG. 10 is a photograph of the angle adjustment template jig, and is a plan view showing the state in which the template jig is attached to an instrument and adjustment is performed using the second reference marker MB2. [Figure 8a] FIG. 10 is a conceptual plan view showing another embodiment of a switch for performing angular coordinate calibration. [Figure 8b] FIG. 10 is a conceptual diagram showing another embodiment of a switch for performing angular coordinate calibration, illustrating the principle of the switch; DETAILED DESCRIPTION OF THE INVENTION

[0017] Next, the present invention will be described in more detail with reference to the accompanying drawings where appropriate. Fig. 1 is a cross-sectional view of an instrument 100, etc., on which a rotation angle detection module is to be installed, in accordance with a method for installing a rotation angle detection module in an instrument according to the present invention. The pointer rotation angle detection device 1 includes a pointer magnet 10 and a detection module 20. To understand the relationship between these, refer to Figs. 2a to 2c and 3a to 3c.

[0018] The instrument 100 comprises a main body 102 that houses a Bourdon tube mechanism 103, an outer frame 104 that is screwed onto the main body, and a transparent cover plate 105 and an inner cover 106 that are held by the outer frame 104, and houses a scale plate 110 inside, forming a fixed part 101. On the other hand, the movable part comprises a pointer 120 that is supported on the rotation axis of the Bourdon tube mechanism 103 via a pointer collar part 121.

[0019] As shown in Figures 1 and 2, the pointer magnet 10 is plate-shaped and has a polarity in the planar direction of the plate. For convenience of explanation, a direction indicator 12 is displayed on the surface of the pointer magnet, indicating the polarity direction or a direction perpendicular to the polarity, and is visible from the surface of the pointer magnet. However, as described below, the direction indicator 12 is not essential to the implementation of this invention. When the direction indicator 12 has parallel red and blue lines 12a and 12b oriented to the left and right from the central through-hole 11 toward the tip of the pointer, the magnetic field line direction MD from the north pole to the south pole is oriented toward the tip of the pointer. A central hole 122 is formed in the pointer collar 121, through which the pointer center axis P1 passes. Meanwhile, the magnet center axis P2, which is the center of the magnet 10, passes through the aforementioned through-hole 11. The pointer center axis P1 and the magnet center axis P2 are aligned according to the direction described below.

[0020] 3a to 3f, detection module 20 includes cylindrical holder 21 with openable and closable lid 21a at the tip, and includes magnetic sensor 22, button battery 23, and substrate 28 having components for performing various processes inside. Switch 26, which will be described later, may be operated from the outside by removing lid 21a, or a through-hole may be provided in holder 21 so that it can be operated from the outside with a pin, or a portion of holder 21 may be movable so that it can be operated from the outside.

[0021] The substrate 28 includes a voltage adjustment unit 23a for the battery 23, output correction units 24a and 24b for the X and Y components from the magnetic sensor 22 (described later), a calculation unit 25a for the sensor output, an output unit 25b for outputting the calculation result as an angle, a communication unit 25c for transmitting output data to the outside via communication, and the above-mentioned switch 26.

[0022] 3f and 5b, the magnet rotation jig 50 includes a stepping motor 51 capable of detecting and controlling angular coordinates using a rotary encoder, a magnet holder 51a fixed to the rotation shaft of the stepping motor 51 and holding the magnet, a stepping motor control unit 52, and a detection module holder 53. The detection module holder 53 has an opening 54 that receives the holder 21 of the detection module 20, and multiple fitting grooves 54a that fit into multiple markers 21c formed at the base of the holder 21 to regulate rotation. The fitting grooves 54a and the markers 21c are fitted into only one angular phase in the rotation direction, thereby determining the angular coordinate uniformly.

[0023] The structure of the magnetic sensor 22 will now be described with reference to Figures 3d, 3e, and 4. The magnetic sensor 22 has first and second bridges BX and BY, whose polarities are 90 degrees opposite each other. Each bridge uses four TMR (tunnel magnetoresistance) elements. In this element, the free layer and pinned layer are joined by an insulating barrier layer. When the magnetization directions of the two layers are antiparallel, the resistance increases and only a weak current flows. On the other hand, when the magnetization directions of the free layer and pinned layer are parallel, the resistance decreases and a large current flows. Because the magnetization direction of the free layer follows the external magnetic field, the magnetization direction can be changed by rotating the magnet.

[0024] The first bridge BX has two first TMR elements Dx1 whose pinned layer magnetization direction is oriented in the X+ direction and two second TMR elements Dx2 whose pinned layer magnetization direction is oriented in the X- direction. Meanwhile, the second bridge BY for detection in the Y direction perpendicular to the X axis has two third TMR elements Dy1 whose pinned layer magnetization direction is oriented in the Y+ direction and two fourth TMR elements Dy2 whose pinned layer magnetization direction is oriented in the Y- direction.

[0025] Each bridge is connected to Vcc and GND from the voltage regulator 23a as inputs. Sin+ and Sin- are output from the first bridge BX, and Cos+ and Cos- are output from the second bridge BY. The sensor center axis P3, which is perpendicular to the XY plane and serves as the center of rotation of the magnetic field direction line that controls the bridges of the sensor 22, passes near the center of the sensor 22 chip. The sensor zero axis 22b, which serves as the reference for measuring the angle θ of the magnetic field direction line MD around this sensor center axis P3, is the X axis. In the circuit diagram of Figure 3d, the clockwise direction is the positive direction of θ, and in the chip plan view of Figure 3e, the counterclockwise direction is the positive direction of θ (Figures 3d and 3e are reversed). In addition, a sensor marker 22a is provided on the surface of the sensor 22 chip to identify the position and terminal type of the sensor zero axis 22b.

[0026] 4 is a graph showing the relative values ​​of the output voltages of the first and second bridges BX and BY when the magnet is rotated using the magnet rotation jig 50, with the first source output Vox and the second source output Voy being 90 degrees out of phase. If the magnet is rotated with the sensor zero axis 22b of the sensor 22 oriented directly below the instrument, the zero scale position will start from the position indicated by symbol Ma1 and the 270-degree scale position will end at the position indicated by symbol Ma2.

[0027] In the figure, the first original output Vox and the second original output Voy have different output ranges, and by correcting and matching these ranges, the output value alone can be understood as sinθ and cosθ, and θ can be directly derived using the output correction value. Therefore, by dividing the second original output Voy by the maximum range, this is used as the second corrected output Vy, with maximum and minimum values ​​of +-1, for subsequent calculations. The first original output Vox and the first corrected output Vx are also processed in the same way (for convenience, Vox and Vx are treated as the same). In order to perform the above correction, a relative rotation step is performed in advance to rotate the magnet and magnetic sensor relative to each other.

[0028] An example of a method for deriving θ will be shown below. If the absolute value of Vx is larger than the absolute value of Vy, the following formula is used. θ=arctan(Vy / Vx)

[0029] If the absolute value of Vx is smaller than the absolute value of Vy, the following formula is used. θ=arccot(Vy / Vx))

[0030] The mounting of the sensor 22 configured as described above on the substrate 28 will be described with reference to Figures 3b, 3c, 3d, and 3e. In this example, for ease of explanation, the sensor zero axis 22b of the sensor 22 is positioned directly below the holder 21. The sensor zero axis 22b of the sensor 22 is aligned using the sensor marker 22a, and the sensor 22 in Figure 3e is flipped over and the rotation phase is defined using the angular coordinates in Figure 3d. At this time, the sensor central axis P3 is aligned with the central axis of the cylindrical portion of the holder 21. By aligning the sensor central axis P3 with the central axis of the cylindrical portion of the holder 21 in this way, the rotation axis of the stepping motor 51 and the sensor central axis P3 are aligned when the magnet rotation jig 50 is mounted in the opening 54.

[0031] The central axis of the cylinder of the holding part 21 and the central axis of the transparent cover plate 105 are aligned and fixed together. The transparent cover plate 105 of the existing instrument may be used as is, or an equivalent one may be provided in exchange. The flange 21b of the holding part 21 is used for fixing.

[0032] A clearance C is formed between the outer diameter d2 of the transparent cover plate 105 and the inner diameter d1 of the outer frame 104 for the convenience of fitting the transparent cover plate 105. Due to the presence of this clearance C, when the transparent cover plate 105 with the detection module 21 fixed thereto is attached to the outer frame 104, a misalignment occurs between the pointer central axis P1 and the sensor central axis P3, which may result in an error. This misalignment between the axes P1 and P3 is corrected using the template jig 70, which will be described later.

[0033] 3b, 3c, 3d, and 3e are compared with FIG. 4 to explain the markers M for matching the angular coordinates (limited to those related to the rotation angle) of the detection module 20 with the scale 110a of the scale plate 110. In FIG. 3c, first to sixth markers M1 to M6 configured as fitting ribs 21c and a seventh marker M7 that also serves as a battery 23 or a battery holder are provided.

[0034] Let us consider the case where each phase is aligned with the scale 110a of the scale plate 110 fixed to the instrument 1. If the first marker M1 is placed at the lowest position of the scale 110a, the sensor zero axis 22b will be located here. Using this as a reference, the second and third markers M2 and M3 are placed at positions of + / -45 degrees in angular coordinates around the sensor central axis P3, the fourth and fifth markers M4 and M5 are placed at positions of + / -90 degrees, and the sixth marker M6 is placed at a position of + / -180 degrees. By associating any of these first through sixth markers M1 through M6 with the corresponding angles of the scale 110a, the angular coordinates of the sensor 22 can be aligned with the scale plate 110. Furthermore, the seventh marker M7, which also serves as the battery 23 or battery holder, corresponds to the same angular coordinate as the fourth and fifth markers M4 and M5, and by aligning the orientation of the battery 23 with the scale plate 110, the angular coordinate of the sensor 22 can be aligned with the scale 110a of the scale plate 110. The transparent cover plate 105 or the scale 110a may be contaminated and have an unreadable phase, and providing multiple markers M as described above can address this situation.

[0035] Here, we consider the necessity of using the magnet rotation jig 50. If the maximum amplitudes of Vox and Voy mentioned above match, θ can be found from their relationship, and there is no need to use the magnet rotation jig 50 for correction. However, if these maximum amplitudes do not match, it is difficult to find θ using an inverse trigonometric function, so it is necessary to rotate the magnet at least 360 degrees to find the maximum amplitude and then make corrections.

[0036] Incidentally, if the angular coordinate of the sensor zero axis 22b of the sensor 22 and the angular coordinates of the pointer 120 and the magnetic field line direction MD can be identified, θ can be found from the sensor output using the characteristic curve in Figure 4 and the angular coordinate of the sensor zero axis 22b, and there is no need to use the magnet rotation jig 50. However, if the orientation of the magnet relative to the pointer 120 cannot be identified and it is attached to the pointer collar part 121, the angular coordinates of the pointer 120 and the magnetic field line direction MD cannot be identified in advance, and the angular coordinate of the pointer 120 cannot be found from the characteristic curve in Figure 4 alone, so the angular coordinate calibration using the switch 26 described below is required.

[0037] In this angular coordinate calibration process, the sensor 22 is attached to the substrate 28, the relative angle of which is fixed to the holder 21. Then, as will be described later, the magnet 10 is affixed to the pointer collar 121 without regard to orienting the direction indicator mark 12 with respect to the pointer 120. Then, when the orientation of, for example, the second marker M2 on the holder 21 matches that of the pointer 120, the switch 26 is pressed and the θ position in the characteristic graph of Figure 4 is recorded. For example, the position of Mb1 (180 degrees in terms of the sensor characteristics) is the zero position of the scale plate 110, and the position of Mb2 (450 degrees in terms of the sensor characteristics) is the 270 degree position on the scale plate 110.

[0038] Next, we will explain the configuration of the template jig 70 for adjusting and fixing the rotational position of the detection module 20 together with the transparent cover plate 105 to the outer frame. This template jig 70 includes a template body 71 made of a disk-shaped transparent resin plate, a spacer 72 that separates this template body 71 from the transparent cover plate 105 to prevent interference with the outer frame, and an opening 73 formed in this spacer. Multiple center position gauges 74 made of circles of different diameters are arranged concentrically around the central axis of the opening 73, and an angle scale 75 is displayed around the periphery.

[0039] The central axis of the opening 73 of the template jig 70 is aligned with the central axis of the cylindrical portion of the holder 21, thereby aligning the pointer central axis P1 and the magnet central axis P2 with the sensor central axis P3. Six fitting grooves 73a are formed around the periphery of the opening 73 to receive the fitting ribs 21c. The fitting grooves 73a are formed at positions corresponding to the first to sixth markers M1 to M6, allowing the rotational phases of the template jig 70 and the detection module 20 to be determined at a single position and the relationship between them to be fixed. Because the angle scale 75 is positioned radially outward from the first to sixth markers M1 to M6, it is closer to the scale 110a on the scale plate 110 and functions as another marker M, making angle adjustment easier.

[0040] Here, with reference to FIG. 5a, we will consider the procedures and work elements for attaching the magnet 10 and detection module 20 using the rod-shaped jig 60, template jig 70, and switch 26. First, for accurate measurement using the sensor 22 and magnet 10, "element Sa: alignment of P1-3" and "element Sb: alignment of magnet-sensor angular coordinates" are required. For "element Sa: alignment of P1-3," "element Sa1: alignment of P1 and P2" and "element Sa2: alignment of P1 and P3" are required. By aligning the magnet center axis P2 with the sensor center axis P3 via the pointer center axis P1, the magnetic field line direction MD is rotated around the sensor center axis P3, reducing measurement errors.

[0041] For "Element Sb: Aligning the magnet and sensor angular coordinates," four elements are required: "Sb1: Calibrating the maximum amplitude of Vox and Voy," "Sb2: Correlating the rotation angle and sensor output (angular coordinate calibration)," "Sb3: Fixing the pointer and magnet direction," and "Sb4: Aligning the sensor with the angular coordinate of the scale plate."

[0042] For element Sa1, "element Sa11: Align the magnet through hole and the collar central hole" is required, and for element Sb3, "element Sb31: Align the pointer and the direction indicator mark" is required, and this work is performed using a rod-shaped jig 60.

[0043] For element Sa2, "element Sa21: align the center of the template circle and outer frame" is required, and for element Sb4, "element Sb41: align the marker with the scale plate" is required, and these operations are performed by the template jig 70.

[0044] For element Sb1, "element Sb11: rotate the magnet one or more times to derive the maximum amplitude of Vox and Voy" is required, and this operation is performed using the magnet rotation jig 50, magnet 10, and detection module 20. However, element Sb11 is not necessary if a sensor 22 with the same maximum amplitude of the two-bridge outputs Vox and Voy is used. For element Sb2, "element Sb21: align the pointer and marker to calibrate the angular coordinate, and establish a relationship between the pointer angular coordinate and the sensor output" is required. This step is performed by calibrating the angular coordinate with switch 26 while aligning marker M with pointer 120, as described above.

[0045] Based on the above, we will explain how to attach the magnet 10 and detection module to the instrument, assuming that the process using the magnet rotation jig 50 has already been completed or that the conditions are met so that it does not need to be performed.

[0046] First, we will explain the process of attaching the magnet 10 to the pointer collar 121 using the rod-shaped jig 60. The outer frame 104 is rotated and removed, and the transparent cover plate 105 is removed to expose the pointer 120. Then, as shown in FIG. 6, the pointed shaft 62 of the rod-shaped jig 60 is passed through the through-hole 11 of the magnet 10 to hold the magnet 10 to the rod-shaped jig. At this time, an adhesive 14 such as double-sided tape is provided on the back of the magnet. In this state, as shown in FIG. 6, the tip of the shaft 62 is aligned with the central hole 122 of the pointer collar 121 of the instrument, and the magnet 10 is attached to the center of the pointer collar 121 with the adhesive 14. There is no need to align the direction of the direction indicator 12 with the direction of the pointer 120.

[0047] Next, we will explain how to attach the detection module 20 to the instrument 100 and adjust its position using the template jig 70 (small template jig 70B) shown in Figures 7a and 7b. As shown in Figure 7c, with the outer frame 104 and transparent cover plate 105 removed, the transparent cover plate 105 to which the detection module 20 has been fixed as described above is temporarily attached to the instrument 100 using the outer frame 104. The lid 21a is removed from the tip of the holding part 21, and the opening 73 is penetrated, and the six engaging ribs 21c are engaged with the engaging grooves 73a to restrict relative rotation. At this time, the spacer 72 raises the template body 71 from the transparent cover plate 105, preventing interference with the outer frame 104.

[0048] In this state, the angular coordinate calibration and installation work is performed through the steps shown in Figures 7d to 7f. For convenience, the step in Figure 7f will be described first. The angular scale 75, which serves as a marker, is used to align the scale and angular phase on the scale plate 110. It is convenient to align the angular coordinates of the first through sixth markers M1 to M6 shown in Figure 3c, for example, the second marker M2 in Figure 7f, using the angular scale 75. Simultaneously, the center position gauge 74 of the template jig 70 is used to fine-tune the position of the transparent cover plate 105 so that the sensor center axis P3 coincides with the pointer center axis P1 and the distance between the inner edge of the outer frame 104 and the circle is uniform around the entire circumference. Once the adjustment is complete, the outer frame 104 is tightened to secure the transparent cover plate 105, the template jig 70 is removed, and the lid 21a is attached to complete the process. Although angle adjustment can be performed using the mating ribs 21c or the battery 23 at the positions of the first to sixth markers M1 to M6, it is more accurate to use the angle scale 75 of the template jig 70, which has a scale and is closer to the scale of the scale plate 110.

[0049] The steps in Figures 7d and 7e show the previous angular coordinate calibration step. In Figure 7d, the angle scale 75 (0 degrees) at the position corresponding to the second marker M2 is aligned with the pointer 120. At this time, the center position gauge 74 is used to align it with the outer frame, and the outer frame 104 is first temporarily tightened. In this state, as shown in Figure 7e, a rod-shaped jig or the like is used to press the switch 26 shown in Figures 3a and 3c, completing the angular coordinate calibration work. Thereafter, the outer frame 104 is loosened again, and the installation work is completed through the steps in Figure 7f above.

[0050] Variations in the alignment of the pointer 120 with the scale 110a of the dial plate 110 in the steps of FIGS. 7d, 7e, and 7f will be described. Essentially, in the steps of FIGS. 7d ​​and 7e, the angle scale 75 (0 degrees) at the position corresponding to the second marker M2 is aligned with the pointer 120, and in the step of FIG. 7f, the angle scale 75 at the position corresponding to the second marker M2 is similarly used to align the angular phase with 0 degrees on the scale 110a of the dial plate 110. In this case, the first reference marker MB1 is commonly used in the steps of FIGS. 7d, 7e, and 7f. Similarly, the third, fourth, and fifth markers may be commonly used as the first reference marker MB1 in the steps of FIGS. 7d, 7e, and 7f. Alternatively, the first reference marker MB1 (e.g., M2, corresponding to zero angle or another first reference angle position) may be used in the steps of FIGS. 7d ​​and 7e, and a different second reference marker MB2 (e.g., M6, corresponding to 135 degrees or another second reference angle position) may be used in the step of FIG. 7f.

[0051] Finally, another embodiment of the present invention will be listed below. The same members as those in the above embodiment are given the same reference numerals. 7a, when the instrument 100 has a large diameter, the graduations on the scale plate 110 are located further outward, so it is preferable to use a template jig 70 having a large diameter template body 71 with graduations 75 extending further outward. However, in an environment where instruments 100 with small diameters are closely spaced, a large template jig 70A with a large diameter template body 71 cannot be used, so it is preferable to use two or more types of large and small template jigs 70A, 70B with template bodies 71 of different outer diameters.

[0052] Figures 8a and 8b are conceptual diagrams showing another embodiment of a switch for performing angular coordinate calibration; Figure 8a is a plan view, and Figure 8b is a principle diagram. While the previous embodiment involved manually operating the switch 26, a proximity detection switch that automatically detects the proximity of the pointer 120 can also be used. In this embodiment, an optical switch 26A is used. This optical switch 26A has an LED 26a and a photodiode 26b fixed to the template body 71 and can be rotated with the template 70 from angle A1 to angle A2, as shown in Figure 8a. The LED 26a and photodiode 26b are positioned on an extension of the marker M. When the pointer 120 approaches, the light from the LED 26a is reflected by the surface of the pointer, changing the current in the photodiode and turning on the interlock switch 26d using the drive circuit 26c. This allows the angular coordinate calibration step to be performed automatically by rotating the template 70 and bringing the LED 26a and other elements close to the pointer 120, without manually operating the interlock switch 26d. Although an optical proximity sensor is used in this example, a capacitance type, a magnetic field detection type, or other proximity sensor may also be used.

[0053] In the above embodiment, the central position gauge 74 of the template jig 70 is made up of multiple concentric circles, but it may also be made up of a radially extending scale, and various modifications are possible as long as the central position can be measured by comparing it with the inner edge of the outer frame 104.

[0054] The template jig 70 and the marker M may be attached to the transparent cover plate 105 as transparent stickers in a removable manner.

[0055] In the above embodiment, a TMR element is used for the bridge element of the sensor 22. However, instead of a TMR element, other types of elements such as an AMR (anisotropic magnetoresistance effect) element or a GMR (giant magnetoresistance effect) element can also be used. [Industrial Applicability]

[0056] The present invention can be used as a method for installing a rotation angle detection module in an instrument that uses a Bourdon tube or other instrument with a pointer, as well as an angle adjustment template jig and pointer magnet used therefor, and a pointer magnet mounting jig and method for installing a rotation angle detection module in an instrument. [Explanation of symbols]

[0057] 1: pointer rotation angle detection device, 10: pointer magnet, 11: through hole, 12: direction indication mark, 14: adhesive body, 20: detection module, 21: holding portion, 21a: lid portion, 21b: flange portion, 21c: fitting rib, 22: magnetic sensor, 22a: sensor marker, 22b: sensor zero axis, 23: button battery, 23a: voltage adjustment portion, 24a, 24b: output correction portion, 25a: calculation portion, 25b: output portion, 25c: communication portion, 26: switch, 26A: optical switch, 26a: LED, 26b: photodiode, 26c: drive circuit, 26d: interlock switch, 28: substrate, 50: magnet rotation jig, 51: stepping motor, 51a: magnet holder, 52: control unit, 53: detection module holder, 54: opening, 54a: fitting groove, 60: rod-shaped jig, 62: shaft, 65: guide, 66: other direction indicator mark, 70: template jig, 70A: large template jig, 70B: small template jig, 71: template body, 72: spacer, 7 3: opening, 73a: fitting groove, 74: center position gauge, 75: angle scale, 100: instrument, 101: fixing part, 102: main body part, 103: Bourdon tube mechanism, 104: outer frame (cover), 105: transparent cover plate, 106: inside cover, 110: scale plate, 110a: scale, BP: zero angle position, M: marker, M1 to M7: first to seventh markers, MB1: first reference marker, MB2: second reference marker, 120: pointer, 121: pointer collar part, 122: center hole, BX, BY: first and second bridges, Dx1: first TMR element, Dx2: second TMR element, Dy1: third TMR element, Dy2: fourth TMR element, MD: direction of magnetic field lines, Ma1, Mb1: zero scale position, Ma2, Mb2: 270 degree scale position, Vox: first original output, Voy: second original output, Vx: first corrected output, Vy: second corrected output, d1: inner diameter of outer frame, d2: outer diameter of transparent cover plate, C: clearance (play), P1: central axis of pointer, P2: central axis of magnet, P3: central axis of sensor

Claims

1. A method for installing a rotation angle detection module in an instrument so as to be able to detect the rotation angle of a pointer, using a pointer magnet for detecting the rotation angle of a pointer in the instrument using a magnetic sensor, and a detection module for detecting the rotation angle of the pointer based on the relative position of the magnet and the magnetic sensor, comprising: The magnet has a polarity in a direction perpendicular to the axis of rotation of the pointer, and the detection module detects the angle of rotation in the direction of the magnetic lines of force caused by the relative rotation of the pointer magnet on the magnetic sensor, and the detection module has a function of recognizing a specific angle between the sensor and the magnet as zero angle, 135 degrees, or other reference angle position by operating an angular coordinate calibration means at the specific angle, and the detection module has a marker and / or a marker mounting portion that indicates the reference angle position to match the angular coordinate related to the rotation angle relative to the scale plate. a magnet mounting step of mounting the magnet on a pointer collar portion of a pointer positioned at an arbitrary angle; a detection module supporting step of supporting at least the detection module so as to be rotatable relative to a dial plate of a meter having a pointer about the rotation axis; an angular coordinate calibration step of aligning the marker with the position of the pointer and operating the angular coordinate calibration means; A method for installing a rotation angle detection module in an instrument, comprising a detection module adjusting and rotating step of adjusting and rotating the detection module and fixing it so that the marker coincides with the reference angular position.

2. 2. The method for installing a rotation angle detection module in an instrument according to claim 1, wherein said angular coordinate calibration means is a switch.

3. 2. The method for installing a rotation angle detection module in a gauge according to claim 1, wherein said angular coordinate calibration means is a proximity detection sensor which is closest when the positions of said pointer and said marker coincide with each other.

4. 2. A method for installing a rotation angle detection module in an instrument as described in claim 1, wherein the pointer magnet is plate-shaped and has a through hole passing through the plate, and the shaft of the jig is passed through this through hole and its tip is engaged with the central hole of the pointer collar portion, thereby fixing it close to the pointer collar portion.

5. A method for installing a rotation angle detection module in an instrument according to any one of claims 1 to 4, wherein the markers comprise a first reference marker corresponding to a first reference angle position such as zero angle, and a second reference marker corresponding to a second reference angle position such as 135 degrees, and either the first or second reference marker is used in the angular coordinate calibration step, and the other reference marker is used in the detection module adjustment and rotation step.

6. 5. A method for installing a rotation angle detection module in an instrument according to claim 1, wherein the detection module houses the magnetic sensor in a cylindrical holder and is positioned near the center of a circular transparent cover plate that covers the pointer, and the magnetic sensor can be rotated and fixed together with the transparent cover plate around the central axis relative to the scale plate by holding the outer periphery of the holder with fingers.

7. The instrument has an outer frame capable of fixing an edge of the transparent cover plate, and the outer diameter of the transparent cover plate is smaller than the inner diameter of the outer frame, so that a clearance exists between them; 7. A method for installing a rotation angle detection module in an instrument according to claim 6, further comprising: an angle adjustment template jig having an opening; the holding portion being capable of being inserted through the opening and attached to the template jig so as not to be rotatable relative to the template jig; and the template jig having a center position gauge for aligning the center of the sensor with respect to the outer frame by the relative distance from the outer frame, and an angle scale for measuring the angle, which is the marker.

8. 8. An angle adjustment template jig used in the method of installing a rotation angle detection module in an instrument according to claim 7, comprising a plate-shaped template body that can be attached by inserting the holding portion therethrough so as to be unable to rotate relative to the outer frame, and the template body has a center position gauge that aligns the center of the sensor with respect to the outer frame based on the relative distance from the outer frame, and an angle scale for measuring angles.

9. 9. The angle adjustment template jig according to claim 8, wherein the center position gauge is a plurality of concentric circles.

10. 10. The angle adjusting template jig according to claim 9, wherein the template bodies include at least two bodies with different outermost diameters, and the maximum diameter of the circle of the large diameter template body is larger than the maximum diameter of the circle of the small diameter template body.

Images