Valve stroke measuring jig

Abstract

To provide a valve stroke measuring jig capable of measuring the stroke of a valve stem with high precision using a dial gauge.SOLUTION: A valve stroke measuring jig includes a first jig 4 that is detachably fixed to a stationary body 2e that is stationary relative to the valve 2 and that holds a dial gauge 3 so that a measuring element 3a of the dial gauge 3 is aligned with a valve stem 2a of the valve 2, and a second jig 5 that is detachably attached to the valve stem 2a and has an abutment surface 51a against which the measuring element 3a of the dial gauge 3 held by the first jig 4 abuts.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a valve stroke measuring jig. [Background technology]

[0002] In power plants and related facilities, various valves of various sizes are installed in the piping to control and adjust the flow of fluids according to their purpose. After these valves are installed in power plants and related facilities, they are tested to ensure that they function normally and are sound.

[0003] These valves often use valves that adjust the flow rate of fluid by moving a valve stem, to which a valve disc is attached, up and down without rotating it. One test for this type of valve is to check the stroke (operating length) of the valve stem. The stroke of the valve stem is measured using a dial gauge. That is, the dial gauge is fixed to the valve stem so that the measuring point at the tip of the dial gauge touches a stationary object, and the displacement caused by the up and down movement of the valve stem is read on the dial gauge. A magnetic stand (magnetic base) is sometimes used to fix the dial gauge to the valve stem. The magnetic stand is equipped with a magnetic holder base, whose magnetic attraction can be turned on and off by turning a switch on and off, and an articulated arm supported by the magnetic holder base. The magnetic holder base is attached to the periphery of the valve stem, and the dial gauge is fixed to the tip of the arm, etc., to measure the valve stem stroke. Summary of the Invention [Problem to be solved by the invention]

[0004] With the need for automatic control of valve stem stroke, it is necessary to measure the valve stem stroke with high precision (for example, in the μm range).

[0005] However, in the conventional stroke measurement method described above, the magnetic holder base is attached to the circumferential surface (curved surface) of the valve stem by magnetic force, which makes the fixation of the magnetic holder base to the valve stem unstable and can cause fluctuations in the contact point of the tip of the probe. This fluctuation can cause errors in the measurement, making it difficult to measure the valve stem stroke with high accuracy.

[0006] An object of the present invention is to provide a valve stroke measuring jig that can measure the stroke of a valve stem with high accuracy. [Means for solving the problem]

[0007] The present application includes multiple means for solving the above-mentioned problems, and one example thereof includes a first jig that is detachably fixed to a stationary body that is stationary relative to the valve and holds the dial gauge so that the measuring point of the dial gauge is aligned with the valve stem of the valve, and a second jig that is detachably attached to the valve stem and has an abutment surface against which the measuring point of the dial gauge fixed by the first jig abuts. [Effects of the Invention]

[0008] According to the present invention, the dial gauge can be stably held by the first jig fixed to the stationary body while the measuring element is in contact with the second jig attached to the valve stem, thereby enabling highly accurate measurement of the valve stem stroke. Problems, configurations, and effects other than those described above will become clear from the following description of the embodiments. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a front view showing a state in which a valve stroke measuring jig according to an embodiment of the present invention is attached to a valve. FIG. [Figure 2] 1 is a side view showing a state in which a valve stroke measuring jig according to an embodiment of the present invention is attached to a valve. FIG. [Figure 3] FIG. 2 is a front view of a first jig according to the embodiment of the present invention. [Figure 4] FIG. 4 is a plan view of a second jig according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] The configuration and operation of a valve stroke measuring jig according to an embodiment of the present invention will be described below with reference to the drawings. In each drawing, the same reference numerals denote the same parts.

[0011] Fig. 1 is a front view showing a state in which a valve stroke measuring jig 1 according to an embodiment of the present invention is attached to a valve 2. Fig. 2 is a side view showing a state in which a valve stroke measuring jig 1 according to an embodiment of the present invention is attached to a valve 2.

[0012] The valve stroke measuring jig 1 is a jig for measuring the operating length (stroke) of the valve stem 2a of the valve 2 with a dial gauge 3 with high precision (for example, in μm units).

[0013] The valve 2 of this embodiment is a device that controls the flow rate of fluid flowing through the flow path 2c in the valve box 2b using a valve body attached to the lower end of the valve stem 2a, which moves up and down without rotating circumferentially, thereby regulating the pressure of the fluid discharged from the valve 2.

[0014] The valve 2 is provided with a valve body 2b, a valve element 2d, a valve stem 2a, a cover 2e, a jack support 2f, a drive unit 2g, and an electric actuator (not shown).

[0015] The valve box 2b is the body of the valve 2 and has a flow path 2c and a valve seat 2h inside. The valve element 2d is a component for opening and closing the flow path 2c. The flow path 2c is closed by joining the valve element 2d to the valve seat 2h.

[0016] The valve rod 2a is a component that controls the flow rate of the fluid flowing through the flow path 2c by moving the valve element 2d at the lower end up and down, thereby varying the distance between the valve element 2d and the valve seat 2h, thereby adjusting the pressure of the fluid discharged from the valve 2.

[0017] The cover 2e is a component that closes the top of the valve box 2b. The jack support 2f is a component that protrudes upward from the cover 2e and supports the drive unit 2g and the electric actuator.

[0018] The drive unit 2g is a device that converts the rotation output from the rotating shaft of the electric actuator installed above to move the valve stem 2a up and down. The drive unit 2g moves the valve stem 2a in the axial direction without rotating in the circumferential direction. The electric actuator is a device that converts an electrical signal into rotation of the rotating shaft.

[0019] The dial gauge 3 is, for example, a spindle-type digital dial gauge that can measure in units of 1 μm.

[0020] The valve stroke measuring jig 1 includes a first jig 4 and a second jig 5.

[0021] The first jig 4 is removably fixed to a stationary body (in this embodiment, the lid 2e) that is stationary relative to the valve 2, and is a jig that fixes the dial gauge 3 so that the measuring probe 3a of the dial gauge 3 is aligned with the valve stem 2a of the valve 2.

[0022] FIG. 3 is a front view of the first jig 4 according to this embodiment.

[0023] The first jig 4 preferably has two pillars 41a detachably fixed to the stationary lid 2e, and a beam 42 spanning the two pillars 41a, and the dial gauge 3 is preferably held on the beam 42 by a holder 43.

[0024] In this embodiment, the two pillars 41a are main pillars fixed to the magnet holder base 41b of the magnet stand 41, and are detachably fixed to the stationary body (lid 2e) made of a ferromagnetic material by turning on / off the magnetic switch 41c of the magnet holder base 41b.

[0025] Moreover, it is preferable that the magnet holder base 41b is detachably fixed onto the flat surface of the stationary body (the upper surface 2i of the lid 2e).

[0026] In the above, an embodiment has been shown in which the first jig 4 is detachably fixed to the stationary body 2e by the magnet stand 41. However, this is not limiting. For example, the first jig 4 may be detachably fixed to the stationary body by a bolt.

[0027] Each of the two columns 41a is preferably attached with a muff 44. The columns 41a and the beam 42 are fixed by the muffs 44 so that they intersect at approximately right angles.

[0028] The beam 42 is, for example, a metal round bar that spans the two support columns 41a and is fixed by muffs 44 so that it intersects the two support columns 41a at approximately right angles. A holder 43 for holding the dial gauge 3 is attached to the beam 42, and the holder 43 holds the dial gauge 3 so that the probe 3a is aligned with the valve stem 2a.

[0029] The second jig 5 is detachably attached to the valve stem 2a and has an abutment surface 51a against which the probe 3a of the dial gauge 3 held by the first jig 4 abuts.

[0030] Fig. 4 is a plan view of the second jig 5 according to this embodiment. As shown in Fig. 4, the second jig 5 preferably includes a first plate 51, a second plate 53 joined to the first plate 51 with bolts 52, and a third plate 55 joined to the second plate 53 with bolts 54.

[0031] The first plate 51 preferably has a contact surface 51a, which contacts the probe 3a of the dial gauge 3, formed on the side facing the probe 3a. The first plate 51 also preferably has a through hole 51c on its side for inserting the bolt 52 therethrough.

[0032] A first screw hole 53a for threading the bolt 52 is provided on the side surface of the second plate 53 facing the first plate 51. A cylindrical collar 56 is provided between the first plate 51 and the second plate 53.

[0033] The threaded portion of the bolt 52 is inserted into the through-hole 51c of the first plate 51 from the opposite side of the second plate 53 toward the second plate 53, passes through the hollow portion of the collar 56, and is tightened into the first screw hole 53a of the second plate 53. This unites the first plate 51 and the second plate 53 together.

[0034] The side surface of the second plate 53 facing the third plate 55 is provided with a first recess 53b recessed along the side surface of the valve stem 2a and a second screw hole 53c for threading the bolt 54. The side surface of the third plate 55 facing the second plate 53 is provided with a second recess 55a recessed along the side surface of the valve stem 2a and a through hole 55b for allowing the threaded portion of the bolt 54 to protrude.

[0035] The first recess 53b and the second recess 55a are pressed against the side surface of the valve rod 2a by clamping the valve rod 2a between the first recess 53b and the second recess 55a and then tightening the threaded portion of the bolt 54 protruding from the through hole 55b into the second screw hole 53c of the second plate 53. Therefore, the second jig 5 is fixed to the valve rod 2a with the valve rod 2a clamped between the first recess 53b of the second plate 53 and the second recess 55a of the third plate 55.

[0036] The second plate 53 and the third plate 55 are preferably formed so that when the valve stem 2a is sandwiched between the first recess 53b and the second recess 55a and the threaded portion of the bolt 54 is tightened into the second screw hole 53c of the second plate 53, a gap G is formed between the second plate 53 and the third plate 55. This allows the second jig 5 to tightly sandwich the valve stem 2a between the second plate 53 and the third plate 55.

[0037] Furthermore, bolts 52 and 54 are preferably hexagon socket bolts. This allows bolt 52 to be tightened into first screw hole 53a and bolt 54 into second screw hole 53c using a hexagon wrench, which prevents interference between tools and the valve 2 and the device in which the valve 2 is installed during work, improving workability. Furthermore, it is preferable to provide countersunk hole 55c on the side of third plate 55 opposite second plate 53. This allows the head of bolt 54, which is a hexagon socket bolt, to be accommodated in countersunk hole 55c, preventing the head of bolt 54 from interfering with valve 2 and the device in which the valve 2 is installed during measurement.

[0038] In order to accurately measure the stroke of the valve stem 2a, it is preferable that the contact surface 51a on the first plate 51 with which the probe 3a of the dial gauge 3 abuts be approximately perpendicular to the dial gauge 3. Meanwhile, the first jig 4 fixes the dial gauge 3 so that the probe 3a of the dial gauge 3 is aligned with the valve stem 2a of the valve 2. Therefore, it is preferable that the second jig 5 is formed with the contact surface 51a, the first recess 53b, and the second recess 55a so that the contact surface 51a on which the probe 3a of the dial gauge 3 of the first plate 51 abuts is positioned approximately perpendicular to the valve stem 2a.

[0039] [effect] The valve stroke measuring jig 1 of this embodiment comprises a first jig 4 that is detachably fixed to a stationary body 2e that is stationary relative to the valve 2 and that fixes the dial gauge 3 so that the measuring element 3a of the dial gauge 3 is aligned with the valve stem 2a of the valve 2, and a second jig 5 that is detachably attached to the valve stem 2a and has an abutment surface 51a against which the measuring element 3a of the dial gauge 3 fixed by the first jig 4 abuts. As a result, the dial gauge 3 can be stably fixed by the first jig 4 fixed to the stationary body 2e with the measuring element 3a abutting against the second jig 5 attached to the valve stem 2a, and the valve stem stroke can be measured with high precision.

[0040] In the valve stroke measuring jig 1 of this embodiment, the first jig 4 preferably has two support columns 41a detachably fixed to the stationary body 2e and a beam 42 spanning the two support columns 41a, with the dial gauge 3 secured to the beam 42 (note that the dial gauge 3 may be secured indirectly to the beam 42 via the illustrated holder 43, or may be secured directly to the beam 42). In a conventional method using a magnetic stand to secure a dial gauge to a valve stem, the dial gauge is secured to an articulated arm, which can easily bend, making the arm unstable and prone to errors. However, securing the dial gauge 3 to the beam 42 spanning the two support columns 41a as described above makes it less likely to bend, allowing for highly accurate measurement of the stroke of the valve stem 2a.

[0041] In this embodiment, the two support columns 41a of the first jig 4 are preferably supported by magnet holder bases 41b that are detachably fixed to the ferromagnetic stationary body 2e by turning on / off magnetic switches 41c, thereby enabling the two support columns 41a, i.e., the dial gauge 3, to be stably fixed to the stationary body 2e.

[0042] In the valve stroke measuring jig 1 of this embodiment, the second jig 5 preferably has two plates (the second plate 53 and the third plate 55) having recesses 53b and 55a recessed along the side surfaces of the valve stem 2a, and the two plates (the second plate 53 and the third plate 55) are fixed to the valve stem 2a with the recesses 53b and 55a sandwiching the valve stem 2a. This allows the second jig 5 to be attached to the valve stem 2a without damaging the side surfaces of the valve stem 2a.

[0043] In the valve stroke measuring jig 1 of this embodiment, it is preferable that the magnet holder base 41b is detachably fixed on the flat surface 2i of the stationary body 2e. In the conventional method of fixing a dial gauge using a magnet stand, the magnet holder base was attached to the circumferential surface (curved surface) of the valve stem, which was unstable. However, by placing the magnet holder base 41b on a flat surface and attaching it in this way, the fixation of the magnet holder base 41b is stable, allowing the stroke of the valve stem 2a to be measured with high accuracy.

[0044] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0045] 1...valve stroke measuring jig, 2...valve, 2a...valve stem, 2e...stationary body (lid), 2i...flat surface of stationary body (top surface of lid 2e), 3...dial gauge, 3a...gauge, 4...first jig, 41...magnetic stand, 41a...support (main pillar), 41b...magnet holder base, 41c...magnetic switch, 42...beam, 43...retainer, 5...second jig, 51...first plate, 51a...contact surface, 53...second plate, 53b...first recess, 55...third plate, 55a...second recess

Claims

1. a first jig that is detachably fixed to a stationary body that is stationary relative to the valve and that holds the dial gauge so that the probe of the dial gauge is aligned with the valve stem of the valve; a second jig that is detachably attached to the valve stem and has an abutment surface against which a measuring element of the dial gauge held by the first jig abuts.

2. 2. The valve stroke measuring jig according to claim 1, the first jig has two support columns detachably fixed to the stationary body and a beam spanning the two support columns, A valve stroke measuring jig characterized in that the dial gauge is fixed to the beam.

3. 3. The valve stroke measuring jig according to claim 2, the stationary body is made of a ferromagnetic material, A valve stroke measuring jig characterized in that the two supports of the first jig are each supported by a magnet holder base that is detachably fixed to the stationary body by turning a magnetic switch ON / OFF.

4. 2. The valve stroke measuring jig according to claim 1, The second jig has two plates with recesses that are recessed along the sides of the valve stem, and the two plates are fixed to the valve stem with the valve stem sandwiched between the recesses.

5. The valve stroke measuring jig according to claim 3, The valve stroke measuring jig is characterized in that the magnet holder base is detachably fixed on the flat surface of the stationary body.

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