Polishing jig and polishing method

Abstract

To provide a polishing jig capable of forming, in a probe, an end surface capable of securing sufficient sealability with a sensor, by polishing.SOLUTION: A polishing jig 8 is for polishing an end surface of a rod-shaped probe provided in a probe type analyzer. The polishing jig 8 is formed with: an insertion hole 81 to which a probe is inserted along a central axis of the probe; and a holding part 82 that holds a tool having a polishing surface that polishes an end surface by rotating around a rotation axis such that the tool faces the end surface. The holding part 82 holds the tool such that the polishing surface is perpendicular to the central axis and is made eccentric with the central axis.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a polishing jig and a polishing method. [Background technology]

[0002] There is a probe-type analyzer in which a sensor is provided at the end of a rod-shaped probe (see, for example, Patent Document 1). The probe is cylindrical. The sensor is attached to the end of the probe and closes the opening at the end of the probe. The sensor separates an inner space inside the cylindrical probe from an outer space outside the probe. For example, if the probe-type analyzer is a gas analyzer, the outer space contains a measurement gas to be measured, and the inner space contains a reference gas to be compared. In such a probe-type analyzer, if the measurement gas enters the inner space and mixes with the reference gas, the measurement accuracy will decrease. For this reason, it is necessary to seal the space between the end of the probe and the sensor.

[0003] Dust and other particles adhering to the end of the probe can cause unevenness on the end of the probe. If unevenness is formed on the end of the probe, a gap may form between the end of the probe and the sensor, impairing the sealing performance. For this reason, the end of the probe is polished to make it smooth.

[0004] To polish the end face of a probe, for example, a power tool having a polishing surface for polishing the end face is used. The polishing surface is provided with a protrusion that is inserted into the inside of the probe. The protrusion on the polishing surface is inserted into the inside of the probe so that the polishing surface abuts against the end face, and the end face is polished by rotating the polishing surface around the protrusion using the power tool. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 5-84853 Summary of the Invention [Problem to be solved by the invention]

[0006] To ensure a tight seal where the probe end face and the sensor come into contact, the probe end face must be perpendicular to the probe's central axis. If the power tool is held by hand while grinding, the power tool may shake, causing the polished end face to tilt relative to the plane perpendicular to the probe's central axis. This tilted polished end face can result in insufficient sealing between the probe and the sensor, allowing the measurement gas to enter the internal space.

[0007] An object of the present invention is to provide a polishing jig that can form, by polishing, an end face of a probe that can ensure sufficient sealing between the probe and a sensor. [Means for solving the problem]

[0008] The polishing jig of the present invention is a polishing jig for polishing the end face of a rod-shaped probe provided in a probe-type analyzer, and is formed with an insertion hole into which the probe can be inserted along the central axis of the probe, and a holding portion that holds a tool having a polishing surface that rotates around a rotation axis to polish the end face, facing the end face, and the holding portion holds the tool so that the polishing surface is perpendicular to the central axis and the rotation axis is eccentric to the central axis. [Effects of the Invention]

[0009] According to the present invention, it is possible to obtain an effect of obtaining a polishing jig that can form, by polishing, an end face of a probe that can ensure sufficient sealing between the probe and a sensor. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of a probe-type analyzer. [Figure 2] FIG. [Figure 3] FIG. 10 is a perspective view showing an example of a tool used to polish the end surface of a probe. [Figure 4]FIG. [Figure 5] 10 is a perspective view showing the polishing jig in a state in which the probe is inserted into the insertion hole and the tool is held by the holding portion. FIG. [Figure 6] 10 is a cross-sectional view of the polishing jig in a state where the probe is inserted into the insertion hole and the tool is held by the holding portion. FIG. [Figure 7] 10 is a flowchart showing a procedure for polishing a probe using a polishing jig. [Figure 8] FIG. 10 is a perspective view of a polishing jig according to a first modified example. [Figure 9] FIG. 10 is a perspective view of a polishing jig according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0011] A polishing jig and a polishing method according to an embodiment of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the embodiment described below.

[0012] [Embodiment 1] <Probe-type analyzer> FIG. 1 is a cross-sectional view showing the schematic configuration of a probe analyzer. Probe analyzer 1 has a probe 2 and is a measuring instrument that analyzes the components of the surrounding environment in which probe 2 is installed. In FIG. 1, a zirconia oxygen analyzer is shown as an example of probe analyzer 1. Probe analyzer 1 includes probe 2 and sensor 3. Probe 2 is a member that extends like a rod. Probe 2 has a cylindrical shape with a cavity formed inside, for example, a cylindrical shape with a circular cross section.

[0013] 2 is a perspective view of the sensor. The sensor 3 is provided at the end of the probe 2. The sensor 3 includes a cover 31 and a zirconia tube 32.

[0014] The lid 31 abuts against the end face 21 of the probe 2 and closes the opening formed at the end of the probe 2 together with the zirconia tube 32. The surface of the lid 31 that abuts against the end face 21 of the probe 2 is referred to as the abutment surface 31a, and the surface behind the abutment surface 31a is referred to as the exposed surface 31b. A through hole 31c is formed in the center of the lid 31.

[0015] The zirconia tube 32 is made of zirconia and has a cylindrical shape with a bottom. The zirconia tube 32 is inserted into the through-hole 31c of the lid 31. The zirconia tube 32 is inserted with its opening facing the exposed surface 31b. A seal is formed between the inner peripheral surface of the through-hole 31c of the lid 31 and the outer peripheral surface of the zirconia tube 32.

[0016] The sensor 3 provided on the end face 21 of the probe 2 divides the space in which the probe 2 is installed into an inner space 41 inside the cylindrical probe 2 and an outer space 42 outside the probe 2. The zirconia tube 32 is inserted into the inner space 41. Here, the opening of the zirconia tube 32 is provided on the exposed surface 31b side, so the space inside the zirconia tube 32 is included in the outer space 42.

[0017] The probe analyzer 1 is placed in an atmosphere containing the measurement gas to be measured. In this state, the measurement gas is present in the outer space 42. That is, the inner surface of the zirconia tube 32 is in contact with the measurement gas. Meanwhile, a reference gas is introduced into the inner space 41. That is, the outer surface of the zirconia tube 32 is in contact with the reference gas.

[0018] In the probe-type analyzer 1, an electromotive force is generated due to the concentration difference between the measurement gas and the reference gas, and the concentration of the measurement gas can be calculated based on this electromotive force. In the first embodiment, a zirconia oxygen analyzer is used as an example of the probe-type analyzer 1, and in this case, an electromotive force is generated due to the difference between the oxygen concentration of the measurement gas and the oxygen concentration of the reference gas, and the oxygen concentration is measured based on this electromotive force.

[0019] If the measurement gas enters the inner space 41 from the outer space 42 and mixes with the reference gas, the accuracy of the concentration measurement will decrease. Therefore, it is important that the gap between the end face 21 of the probe 2 and the contact face 31a of the sensor 3 is sealed.

[0020] When used in a measurement gas, unevenness may occur on the end face 21 of the probe 2. For example, the unevenness may occur when dust or the like contained in the measurement gas gets in between the end face 21 and the contact surface 31a. If the measurement gas is hot, the difference in the ambient temperature between when measurement is not being performed and when measurement is performed increases, and the difference in the expansion coefficients of the probe 2 and the sensor 3 widens the gap between the end face 21 and the contact surface 31a, making it easier for dust or the like to get in.

[0021] Furthermore, in the probe-type analyzer 1, the sensor 3 may be replaced. When the sensor 3 is replaced, the end face 21 is polished to ensure a tight seal between the contact surface 31a of the sensor 3 and the end face 21 of the probe 2. The end face 21 is polished to a smooth surface. Note that, in order to ensure a tight seal between the contact surface 31a and the end face 21, the angle between the end face 21 and the central axis 22 of the probe 2 is also important. Specifically, it is desirable that the end face 21 and the central axis 22 of the probe 2 are perpendicular. More specifically, it is desirable that the end face 21 is not inclined by 1.7° or more with respect to a plane perpendicular to the central axis 22 of the probe 2, for example.

[0022] <Tools> 3 is a perspective view showing an example of a tool used to polish the end face of a probe. The tool 6 used to polish the end face 21 has an electric screwdriver 61 and an attachment 62. The electric screwdriver 61 rotates the attachment 62 attached to the tip about a rotation axis 7.

[0023] The attachment 62 has a shaft 621 and a polishing portion 622. The shaft 621 is a portion that is held by the electric screwdriver 61. The shaft 621 overlaps with the rotation shaft 7 when held by the electric screwdriver 61. That is, the attachment 62 rotates around the shaft 621. The polishing portion 622 has a polishing surface 622a that is perpendicular to the rotation shaft 7 when the shaft 621 is held by the electric screwdriver 61. The polishing portion 622 has, for example, a disk shape. The polishing surface 622a is a surface that polishes the end surface 21 and is a rough surface. The rough surface of the polishing surface 622a may be formed directly on one side of the polishing portion 622, or may be formed by attaching a polishing sheet having a rough surface to one side of the polishing portion 622.

[0024] The end face 21 may be polished in a horizontal position with the central axis 22 of the probe 2 horizontal, or in a vertical position with the central axis 22 of the probe 2 vertical. When polishing is performed in a horizontal position, the operator must support the tool 6 while polishing, which makes the tool 6 prone to wobble. As a result, the polishing surface 622a is prone to tilt relative to the end face 21, and as a result, the inclination of the polished end face 21 relative to the plane perpendicular to the central axis 22 of the probe 2 is likely to increase. On the other hand, when polishing is performed in a vertical position, the tool 6 can be polished as if placed on the end face 21, so the wobble of the tool 6 is smaller than when the tool is horizontally placed. However, even in a vertical position, the tool 6 may wobble, causing the polishing surface 622a to tilt relative to the end face 21, and thus causing the polished end face 21 to tilt relative to the plane perpendicular to the central axis 22 of the probe 2.

[0025] <Polishing jig> 4 is a perspective view of a polishing jig. The polishing jig 8 is a jig used to polish the end surface 21 of the probe 2 to a smooth surface perpendicular to the central axis 22 using a tool. The polishing jig 8 is formed with an insertion hole 81 into which the probe 2 can be inserted along the central axis 22. The polishing jig 8 also has a holding portion 82 for holding the tool 6.

[0026] Fig. 5 is a perspective view showing the polishing jig with the probe inserted into the insertion hole and the tool held in the holder. Fig. 6 is a cross-sectional view of the polishing jig with the probe inserted into the insertion hole and the tool held in the holder. Fig. 6 shows a cross section cut along a plane including the central axis 22 and the rotation axis 7.

[0027] The holding portion 82 is a groove (or recess) formed so that the tool 6 can be inserted in a direction perpendicular to the central axis 22. The tool 6 is held by the electric screwdriver 61 abutting against the inner peripheral surface of the holding portion 82. When the tool 6 is held in the holding portion 82, a gap is formed between the attachment 62 and the holding portion 82. Therefore, when the tool 6 is held in the holding portion 82, the attachment 62 can be rotated.

[0028] The insertion hole 81 and the holder 82 are in communication. The polishing surface 622a of the tool 6 held by the holder 82 faces and contacts the end face 21 of the probe 2 inserted into the insertion hole 81. Furthermore, the polishing surface 622a of the tool 6 held by the holder 82 is perpendicular to the central axis 22 of the probe 2. This can also be said as the central axis 22 of the probe 2 and the rotation axis 7 of the tool 6 being parallel. Furthermore, the rotation axis 7 of the tool 6 held by the holder 82 is eccentric with respect to the central axis 22 of the probe 2.

[0029] In addition, when polishing is performed with the probe 2 placed horizontally, as shown in Figure 5, a support part 10 may be provided to support the probe 2 at a position away from the polishing jig 8, in order to stabilize the posture of the probe 2 during polishing.

[0030] <Polishing procedure> 7 is a flowchart showing the procedure for polishing a probe using a polishing jig. First, tool 6 is inserted into holder 82, and tool 6 is held by polishing jig 8 (step S1). Next, probe 2, from which sensor 3 has been removed, is inserted into insertion hole 81 with end face 21 side first (step S2). Next, attachment 62 (polishing surface 622a) is rotated while pressing end face 21 of probe 2 against polishing surface 622a, to polish end face 21 (step S3).

[0031] In the processes from step S1 to step S3, end face 21 can be polished to a smooth surface that is perpendicular to central axis 22. In particular, even when polishing is performed with probe 2 placed horizontally, which makes tool 6 prone to shaking, end face 21 can be polished to a smooth surface that is perpendicular to central axis 22 by positioning probe 2 and tool 6 using polishing jig 8.

[0032] However, because the orientation of end face 21 relative to rotation axis 7 about which polished surface 622a rotates is constant, concentric grooves that follow the irregularities of polished surface 622a may be formed on end face 21. Although these grooves are smaller than the irregularities formed on end face 21 before polishing due to the adhesion of dust, etc., it is preferable to form fewer grooves in order to more reliably ensure sealing between contact surface 31a of sensor 3 and end face 21 of probe 2.

[0033] Therefore, after step S3, the probe 2 is rotated around the central axis 22 to change its orientation (step S4), and the attachment 62 is further rotated to polish the end face 21 (step S5). Because the central axis 22 of the probe 2 and the rotation axis 7 of the tool 6 are eccentric, rotating the probe 2 around the central axis 22 can change the orientation of the end face 21 relative to the rotation axis 7, thereby reducing the concentric grooves. Steps S4 and S5 may be repeated any number of times. This does not exclude the insertion hole 81 and the holding portion 82 being formed so that the central axis 22 of the probe 2 and the rotation axis 7 of the tool 6 are aligned on the same line without being eccentric. When the central axis 22 of the probe 2 and the rotation axis 7 of the tool 6 are aligned on the same line, performing steps S4 and S5 does not reduce the concentric grooves, but it is possible to polish the end face 21 to a smooth surface perpendicular to the central axis 22.

[0034] <First Modified Example of Polishing Jig> 8 is a perspective view of a polishing jig according to a first modified example. In a tool 6 held by a polishing jig 8 according to the first modified example, a protrusion 63 is formed on a polishing surface 622a at a position overlapping with the rotation shaft 7. The protrusion 63 protrudes in a direction parallel to the rotation shaft 7.

[0035] In the polishing jig 8 according to the first modification, a holding hole 83 is formed into which the protrusion 63 of the tool 6 can be inserted parallel to the central axis 22. In the polishing jig 8 according to the first modification, the holding hole 83 functions as a holding portion that holds the tool 6. When the tool 6 is held in the holding hole 83, the central axis 22 of the probe 2 and the rotation axis 7 of the tool 6 are eccentric.

[0036] The polishing jig 8 according to the first modification can also polish the end face 21 to a smooth surface perpendicular to the central axis 22. Furthermore, by performing steps S4 and S5 shown in FIG. 7, it is possible to reduce the number of concentric grooves formed on the end face 21. Note that a protrusion may be formed on the polishing jig 8 side, and a holding hole into which the protrusion is inserted may be formed on the polishing surface 622a. In this case, the protrusion on the polishing jig 8 side serves as a holding portion that holds the tool 6 facing the end face 21.

[0037] It should be noted that, whether the probe 2 is placed vertically or horizontally, when polishing is performed without using the polishing jig 8, the end face 21 after polishing is more likely to be inclined with respect to a plane perpendicular to the central axis 22 than when the polishing jig 8 is used. In the polishing jig 8 according to the first modified example, the protrusion 63 is inserted into the holding hole 83, so the posture of the tool 6 when polishing the probe 2 is fixed by the polishing jig 8. Therefore, when the polishing jig 8 according to the first modified example is used, polishing is easy whether the probe 2 is placed vertically or horizontally, and the degree of freedom in the posture of the probe 2 when polishing is increased.

[0038] <Second Modification of Polishing Jig> 9 is a perspective view of a polishing jig according to a second modified example. In a tool 6 held by a polishing jig 8 according to the second modified example, a protrusion 64 is formed on an electric screwdriver 61. The protrusion 64 formed on the electric screwdriver 61 extends parallel to the rotation shaft 7. The protrusion 64 is eccentric to the rotation shaft 7 and does not overlap with the polishing surface 622a.

[0039] In the polishing jig 8 according to the second modification, a holding hole 84 is formed into which the protrusion 64 of the tool 6 can be inserted parallel to the central axis 22. In the polishing jig 8 according to the second modification, the holding hole 84 functions as a holding portion that holds the tool 6. When the tool 6 is held in the holding hole 84, the central axis 22 of the probe 2 and the rotation axis 7 of the tool 6 are eccentric.

[0040] The polishing jig 8 according to the second modification can also polish the end face 21 to a smooth surface perpendicular to the central axis 22. Furthermore, by performing steps S4 and S5 shown in FIG. 7, the number of concentric grooves formed on the end face 21 can be reduced.

[0041] In the polishing jig 8 according to the second modified example, the protrusion 64 is inserted into the holding hole 84, and therefore the posture of the tool 6 when polishing the probe 2 is fixed by the polishing jig 8. Therefore, when the polishing jig 8 according to the second modified example is used, polishing can be easily performed whether the probe 2 is placed vertically or horizontally, and the degree of freedom in the posture of the probe 2 when polishing is increased.

[0042] 〔others〕 Some examples of combinations of the disclosed technical features are set out below.

[0043] (1) A polishing jig for polishing the end face of a rod-shaped probe provided in a probe-type analyzer, the polishing jig having an insertion hole into which the probe can be inserted along the central axis of the probe, and a holding part that holds a tool having a polishing surface that rotates around a rotation axis to polish the end face, facing the end face, the holding part holding the tool so that the polishing surface is perpendicular to the central axis and the rotation axis is eccentric to the central axis.

[0044] (2) The polishing jig according to (1) above, wherein the holding portion is a groove into which the tool can be inserted in a direction perpendicular to the central axis.

[0045] (3) The polishing jig according to (1) above, wherein the holding portion is a holding hole into which a protrusion protruding from the tool in parallel with the rotation axis can be inserted.

[0046] (4) The polishing jig according to (3) above, wherein the protrusion is formed at a position on the polishing surface that overlaps with the rotation axis.

[0047] (5) The polishing jig according to (3) above, wherein the protrusion is eccentric to the rotation axis and is formed at a position that does not overlap with the polishing surface.

[0048] (6) A polishing method for polishing the end face of the probe using the polishing jig described in any one of (1) to (5) above, comprising the steps of: holding the tool in the holding part; inserting the probe into the insertion hole; rotating the polishing surface to polish the end face; rotating the probe around the central axis to change its attitude after the step of polishing the end face; and polishing the end face again after the step of changing the attitude of the probe. [Explanation of symbols]

[0049] 1. Probe-type analyzer 2 probes 21 End face 22 Center axis 3 sensors 31 Lid 31a Contact surface 31b Exposed surface 32 Zirconia tube 41 Inner Space 42 Outside space 6 Tools 61 Electric screwdriver 62 Attachment 621 Shaft 622 Polishing section 622a Polished surface 63,64 Protrusion 7 Rotation Axis 8 Polishing jig 81 Insertion hole 82 Holding part 83,84 Retaining hole 10 Support part

Claims

1. A polishing jig for polishing an end surface of a rod-shaped probe provided in a probe-type analyzer, comprising: an insertion hole into which the probe can be inserted along a central axis of the probe; a holding portion that holds a tool having a polishing surface that rotates around a rotation axis to polish the end surface, in opposition to the end surface; The holding portion is a polishing jig that holds the tool so that the polishing surface is perpendicular to the central axis and the rotation axis is eccentric to the central axis.

2. 2. The polishing jig according to claim 1, wherein the holding portion is a groove into which the tool can be inserted in a direction perpendicular to the central axis.

3. 2. The polishing jig according to claim 1, wherein the holding portion is a holding hole into which a protrusion protruding from the tool in parallel with the rotation axis can be inserted.

4. 4. The polishing jig according to claim 3, wherein the protrusion is formed at a position on the polishing surface that overlaps with the rotation axis.

5. 4. The polishing jig according to claim 3, wherein the protrusion is formed eccentrically with respect to the rotation axis and at a position not overlapping the polishing surface.

6. A polishing method for polishing an end surface of the probe using the polishing jig according to any one of claims 1 to 5, comprising: a step of holding the tool in the holding portion; inserting the probe into the insertion hole; rotating the polishing surface to polish the end face; a step of rotating the probe around the central axis to change its attitude after the step of polishing the end surface; and polishing the end face again after the step of changing the attitude of the probe.

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