JP2017082150A - Adhesion method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of performing the adhesion of magnets for the valve opening detection of a control valve onto a valve shaft at a low cost.SOLUTION: Provided is an adhesion method comprising: the first step where the respective one edges of a plurality of magnetic holders 4 are inserted into a plurality of recessed parts 120 formed on the main face 12A of a base 12, respectively; the second step where a one pack type adhesive cured at a temperature higher than an ordinary temperature is applied to the respective other edges of a plurality of the magnet holders 4 or a plurality of magnets 3; the third step where, after the second step, the magnets 3 are mounted on the other edges of the magnet holders 4; the fourth step where, after the third step, the other edges of the magnet holders 4 mounted with the magnets 3 are inserted into the holes of fixtures 10 for positioning; and the fifth step where the base 12 mounted with a plurality of the magnet holders 4 inserted with the fixtures 1 for positioning is placed in a temperature environment where the adhesive is cured.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a bonding method for bonding a magnet for detecting a valve opening of a control valve on a valve shaft.

  In a chemical plant or the like, a control valve (valve) is used for flow rate process control, and in recent years, a flow control valve in which a function of a flow meter is added to the control valve is increasing.

  The flow control valve includes, for example, a valve (valve element) for controlling the flow rate of fluid, a set value (set opening) of the valve opening sent from the host device, and an actual measured value of the valve opening of the control valve ( And an electric actuator that controls a valve opening degree by rotating a valve shaft connected to the valve body by driving a drive motor (electric motor) based on the deviation. It has a structure as an electric valve.

  The electric actuator includes a displacement detector that detects the valve opening of the control valve as a displacement amount of the valve shaft as a functional unit for measuring the actual opening of the control valve. Potentiometers and non-contact angle sensors (magnetic sensors) are well known (see Patent Document 1).

JP 2014-224736 A

  Prior to the present invention, the inventor of the present application studied the development of a specific measuring instrument in which the function of a calorimeter was added to the flow control valve. As a result of the examination, it became clear that there are the following problems.

  In order for a flow control valve with the function of a calorimeter to be recognized as a specific meter, its structure and instrumental differences must satisfy the technical standards specified by the Ministerial Ordinance. However, when the configuration of the conventional flow rate control valve is applied as it is, it became clear that the above technical level cannot be satisfied with respect to the flow rate measurement accuracy.

  In general, in a flow control valve having a configuration in which the function of a flow meter is added to the motor-operated valve described above, the flow control valve is based on the primary and secondary pressures of the valve and the actual valve opening (actual opening). The flow rate of the fluid inside is measured (calculated). Therefore, in order to increase the measurement accuracy of the flow rate, it is necessary to increase the detection accuracy of the valve opening.

  However, when a potentiometer is used as a part for measuring the valve opening, the potentiometer has a sliding part, and the linearity of the resistance value cannot be guaranteed. It's not easy.

  Therefore, the inventor of the present application examined using a magnetic sensor which is a non-contact angle sensor instead of the potentiometer.

FIG. 9 is a diagram schematically showing a cross-sectional structure of a main part of an electric actuator using a magnetic sensor for a flow rate control valve examined by the present inventor.
As shown in FIG. 9, in an electric actuator 100 that operates a rotary type control valve such as a butterfly valve, for example, a valve shaft (stem) 5 is rotatably supported in a housing 8, and a valve body of the valve shaft 5 A magnet 3 is fixed to the end opposite to the side (not shown) to which the magnet 3 is connected via a magnet holder 4, and a non-contact angle sensor (magnetic sensor) 6 is interposed via a substrate 7 at a position facing the magnet 3. Install.

FIG. 10 is a diagram showing a planar structure of the magnet and the magnet holder when viewed from the direction E of FIG.
As shown in FIG. 10, the magnet 3 is formed in a substantially circular shape in plan view, and is fixed to the surface 4 </ b> A of the magnet holder 4 so that both the N pole and the S pole face the magnetic sensor 6. Thereby, when the electric actuator 100 rotates the valve shaft 5, the magnet 3 arrange | positioned on the valve shaft 5 rotates, and the magnetic flux density around the magnet 3 changes. By detecting the change in the magnetic flux density by the magnetic sensor 6 disposed opposite to the magnet 3, the rotation angle of the valve shaft can be detected and the valve opening of the control valve can be measured.

  However, in order to measure the valve opening with high accuracy in the electric actuator 100, the magnet 3 must be accurately arranged with respect to the magnetic sensor 6. For example, depending on the magnetic sensor employed, the valve opening cannot be measured with high accuracy unless the deviation Δx1 between the detection portion of the magnetic sensor 6 and the central portion of the magnet is 0.05 mm or less.

  In order to position the magnet with high accuracy, for example, it is necessary to use a device such as a mounter for mounting an electronic component or the like on the substrate. However, since these devices are very expensive, the flow control valve This is not a realistic option when considering the production volume.

  Even if the magnet can be positioned with high accuracy, it is not easy to fix the magnet to the magnet holder. That is, the magnet is fixed to the magnet holder by an adhesive, but in order to arrange the magnet with high accuracy, the type of adhesive and the type of dispenser for applying the adhesive must also be considered.

  For example, the application amount of the adhesive necessary for installing a magnet having an outer diameter of Φ8 ± 0.1 with high accuracy in the central portion of a magnet holder having an outer diameter of Φ10 is 1 μL. In order to apply such a small amount of adhesive, the manufacturing cost increases unless the adhesive and dispenser to be used are properly selected.

  For example, when using a two-component adhesive, it is easy to control the timing of curing the adhesive, but the two-component adhesive has a high viscosity, so an inexpensive dispenser that uses air pressure has a minute amount. Cannot be applied with high accuracy. Therefore, it is necessary to use a more accurate and expensive dispenser, which increases the manufacturing cost.

  On the other hand, when a one-component adhesive is used, the viscosity is lower than that of a two-component adhesive, so that it is possible to apply a minute amount with high accuracy using an inexpensive dispenser. It is not easy to control the timing of curing. For example, when a one-component adhesive that cures at room temperature is used, the magnet must be placed immediately after the adhesive is applied to the placement surface of the magnet holder, and before the magnet positioning is completed. In addition, the adhesive may be cured. On the other hand, when an adhesive that cures at a temperature higher than normal temperature is used, in order to fix the magnet to the magnet holder, the magnet holder on which the adhesive is applied and the positioned magnet is placed is placed in a high-temperature space such as an oven. It must be moved one by one. Therefore, the work efficiency when mass-producing the flow rate control valve is poor, and the manufacturing cost is increased.

  The present invention has been made in view of the above problems, and an object of the present invention is to perform adhesion of a valve opening degree detection magnet of a control valve onto a valve shaft at a low cost.

  The method for adhering a magnet according to the present invention uses a positioning jig (10) comprising at least a part of a base (1) formed in a cylindrical shape, and a cylindrical magnet on a cylindrical magnet holder (4). 1 is a bonding method for bonding (3), in which one end of each of a plurality of magnet holders is fitted into a plurality of recesses (120) formed on the main surface of the base (12). (S1), a second step (S2) of applying a one-component adhesive that cures at a temperature higher than room temperature to each other end or a plurality of magnets of a plurality of magnet holders, and after the second step, Third step (S3) for placing the magnet on the other end of the magnet holder, and after the third step, the other end of the magnet holder on which the magnet is placed is connected to the opening (2A of the cylindrical portion of the positioning jig). ) And the fourth step (S4) to be inserted and the positioning jig is inserted. The base number of the magnet holder is placed adhesive characterized by comprising a fifth step of placing the temperature environment to cure (S5).

  In the above bonding method, the cylindrical portion of the base body opens one end (1A) of the base body, and forms a cylindrical internal space having a cross section perpendicular to the axial direction of the base body having a diameter (La) longer than the diameter of the magnet. And forming a first hole (2A) fitted with a clearance fit with the outer peripheral surface of the rod-like member on which the magnet is placed, and a conical or frustoconical internal space coaxial with the first hole, The internal space includes a second hole (2B) in which the diameter of a cross section perpendicular to the axial direction of the base body continuously decreases toward the other end (1C) of the base body.

  In the above description, as an example, reference numerals on the drawing corresponding to the components of the invention are shown in parentheses.

  As described above, according to the present invention, the valve opening degree detection magnet of the control valve is bonded to the valve shaft at a low cost.

FIG. 1 is a cross-sectional view showing the main part of a positioning jig used in the bonding method according to the embodiment of the present invention. FIG. 2 is a plan view showing the main part of the positioning jig when viewed from the direction C of FIG. FIG. 3 is a plan view showing a main part of the positioning jig when viewed from the direction A in FIG. FIG. 4 is a cross-sectional view of the positioning jig when the positioning jig is fitted to the magnet holder on which the magnet is placed. FIG. 5 is a diagram showing a planar structure of a tray used in the bonding method according to the embodiment of the present invention. FIG. 6 is a diagram showing a cross-sectional structure of a tray used in the bonding method according to the embodiment of the present invention. FIG. 7 is a flowchart showing the flow of the bonding method according to the embodiment of the present invention. FIG. 8 is a cross-sectional view showing a main part of a positioning jig according to another embodiment. FIG. 9 is a diagram schematically showing a cross-sectional structure of a main part of an electric actuator using a magnetic sensor for a flow rate control valve examined by the present inventor. FIG. 10 is a diagram showing a planar structure of the magnet and the magnet holder when viewed from the direction E of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The magnet adhering method according to the present embodiment is a non-contact angle sensor (magnetic) in which a valve opening degree detection magnet 3 is installed on a substrate 7 in the manufacturing process of the electric actuator 100 shown in FIG. This is a method for accurately installing the sensor on a position on the valve shaft 5 facing the sensor 6.

  In the bonding method according to the present embodiment, first, the magnet 3 coated with an adhesive is placed on each of the plurality of magnet holders 4 arranged on a dedicated tray using a dedicated positioning jig, and then The adhesive is cured by placing a tray on which the magnet holder 4 in a state where the positioning jig is inserted is placed in a high temperature environment. Hereinafter, the said adhesion method is demonstrated concretely.

(1) Positioning jig First, the positioning jig used in the bonding method according to the present embodiment will be described.

1 to 3 are diagrams showing the structure of a positioning jig used in the bonding method according to the embodiment of the present invention.
FIG. 1 shows a cross-sectional structure of a positioning jig 10 (hereinafter also simply referred to as “jig 10”) in the B-B cross section, and FIG. 2 shows the jig 10 as viewed from the C direction. FIG. 3 shows the planar structure of the jig 10 when viewed from the A direction.

  The jig 10 is an instrument for installing the magnet 3 formed in a substantially circular shape in plan view for detecting the valve opening degree on the magnet holder 4.

  Here, the magnet holder 4 is a rod-shaped (columnar) component that serves as a base for placing the magnet 3 on the tip of the valve shaft 5, and is made of a non-magnetic material (for example, aluminum or copper). . As shown in FIG. 9, the magnet holder 4 has a surface 4A on which the magnet 3 is placed at one end, and is fitted to the valve shaft 5 at the other end. For example, the front end portion on the surface 4A side of the magnet holder 4 has a cylindrical shape, and is formed in a substantially circular shape in plan view as shown in FIG.

Specifically, the jig 10 includes a columnar base 1 and a hole 2 formed in the base 1.
The base 1 is made of, for example, a nonmagnetic material such as aluminum, copper, or resin. As shown in FIGS. 2 and 3, the base 1 is, for example, at least partially formed in a cylindrical shape and has a substantially circular shape in plan view.

  The hole 2 is a through-hole constituted by the first hole portion 2A, the second hole portion 2B, and the third hole portion 2C, and is formed in the base body 1 by a processing technique such as a known metal.

  The first hole 2A is a hole that opens the end 1A of the base to form a cylindrical internal space, and a cross section perpendicular to the axial direction of the base 1 has a diameter La. Specifically, the diameter La of the first hole portion 2A is longer than the diameter of the above-described valve opening degree detection magnet 3, and the first outer peripheral surface of the columnar magnet holder 4 on which the magnet 3 is placed and the first hole portion 2A. The inner wall surface S of the hole 2A has a length that fits with a clearance fit. For example, the fitting tolerance between the magnet holder 4 and the first hole 2A is such that the inner diameter of the first hole 2A is Φ10H6 when the outer diameter of the magnet holder 4 serving as the shaft is Φ10g5.

  The third hole 2C is a hole that opens the end 1C of the base to form a cylindrical internal space, and a cross section perpendicular to the axial direction of the base 1 has a diameter Lc. Specifically, as shown in FIGS. 2 and 3, the third hole 2 </ b> C is formed in a substantially circular shape in plan view on the same axis as the first hole 2 </ b> A. The diameter Lc of the third hole 2 </ b> C is shorter than the diameter of the magnet 3.

  The second hole 2B forms a frustoconical internal space coaxial with the first hole 2A, and the diameter of the cross section of the internal space perpendicular to the axial direction of the base body 1 is directed toward the other end 1C of the base body 1. It is a continuously decreasing hole. Specifically, the inner wall surface of the second hole portion 2B is located on the end portion of the inner wall surface of the first hole portion 2A on the side of the other end 1C of the base 1 and the inner wall surface of the third hole portion 2C on the end 1A side of the base member 1. It is formed in a tapered shape connecting the end portions.

  Here, the second hole 2B is, for example, the center of the inner wall surface S of the first hole 2A and the inner wall surface of the tapered second hole 2B (on the other end 1C side of the base 1 of the first hole 2A). The deviation between the end of the third hole 2C and the end of the third hole 2C on the end 1A side of the base 1 on the end 1A side is, for example, 0.01 mm.

  FIG. 4 is a cross-sectional view of the jig when the jig according to the present embodiment is fitted to the magnet holder on which the magnet is placed.

  When fixing the magnet 3 to the magnet holder 4, as shown in FIG. 4, after the magnet 3 is placed on the surface 4 </ b> A of the magnet holder 4, the jig 10 is fitted into the tip of the magnet holder 4 on the surface 4 </ b> A side. . Specifically, the jig 10 is fitted into the magnet holder 4 until the edge 3 </ b> A of the magnet 3 contacts the inner wall surface of the second hole 2 </ b> B of the jig 10. Thereby, the magnet 3 can be arrange | positioned accurately in the center part of the magnet holder 4. FIG.

  For example, in order to install the magnet 3 having an outer diameter of Φ8 ± 0.1 in the central portion of the magnet holder 4 having an outer diameter of Φ10 g5, the inner diameter of the first hole 2A is set to Φ10H6, and the inner wall surface S of the first hole 2A When the jig 10 having a deviation of 0.01 mm from the center of the inner wall surface of the second hole 2B is manufactured, the deviation width Δx2 between the center of the magnet 3 and the magnet holder 4 is designed to be 0.02 mm or less. Can do.

  Actually, when the inventor prototyped the jig 10 under the above conditions and positioned the magnet 3 using the jig 10, the deviation width Δx2 between the center of the magnet 3 and the magnet holder 4 was 0.005. It was found to be within the range of ~ 0.015 mm. Therefore, if the jig 10 is used, the deviation Δx1 between the detection part of the magnetic sensor 6 and the center part of the magnet 3 can be made 0.05 mm or less.

(2) Tray Next, a dedicated tray used in the bonding method according to the present embodiment will be described.
5 and 6 are diagrams showing the structure of the tray used in the bonding method according to the embodiment of the present invention.
FIG. 5 shows a planar structure of the tray 12, and FIG. 6 shows a cross-sectional structure of the tray 12.

  The tray 12 is an instrument for collectively placing a plurality of magnet holders 4 on which the magnets 3 coated with an adhesive are placed in a high temperature environment. The tray 12 is made of a material such as a metal or a resin having heat resistance sufficiently higher than a temperature necessary for curing the adhesive, for example.

  Specifically, the tray 12 has a plurality of recesses 120 formed in the main surface 12A. Each recessed part 120 is formed at equal intervals along the X direction and the Y direction of the main surface 12A, for example.

  Each recess 120 has a shape corresponding to the shape of the magnet holder 4. Specifically, as shown in FIG. 6, the magnet holder 4 has a shape that can be stabilized on the tray 12 when the magnet holder 4 is inserted into the recess 120 of the tray 12.

  More specifically, the recess 120 can be inserted at the end opposite to the surface 4A of the magnet holder 4 and has a depth Lf (length in the Z direction) that can hold the magnet holder 4 on the tray 12. ) And an inner diameter Le (length in X and Y directions). For example, when the length of the magnet holder 4 in the axial direction is Lg, the depth Lf of the recess 120 is about 1/4 to 1/3 of Lg. Further, when the outer diameter of the magnet holder 4 is Ld, the inner diameter Le of the recess 120 is “Ld + ΔL”. Here, ΔL is, for example, about 0.5 m to 1 m.

  In order to hold the magnet holder 4 on the tray 12 more stably, it is preferable to fit the magnet holder 4 and the recess 120 with a clearance fit.

(3) Magnet Adhering Method Using Positioning Jig Next, the magnet 3 adhering method using the jig 10 and the tray 12 will be specifically described.
FIG. 7 is a flowchart showing a processing procedure of the bonding method according to the embodiment of the present invention.

  As shown in FIG. 7, first, a plurality of magnet holders 4 in a state where the magnet 3 is not placed are inserted into the respective recesses 120 of the tray 12 at the end opposite to the surface 4 </ b> A and attached to the tray 12. Place (S1).

  Next, an adhesive is applied to the surface 4A of each magnet holder 4 placed on the tray 12 (S2). Here, the adhesive is a one-component adhesive that cures at a temperature higher than room temperature (for example, about 100 ° C.).

  Specifically, in step S <b> 2, a predetermined amount of adhesive is applied to the surface 4 </ b> A of the magnet holder 4 using a liquid fixed quantity discharge device. Here, as the liquid dispensing apparatus, for example, an air discharge type dispenser using air pressure can be used. The amount of the adhesive applied is, for example, about 1 μL when a magnet having an outer diameter of Φ8 ± 0.1 is fixed to the magnet holder 4 having an outer diameter of Φ10. For example, the adhesive is applied to the central portion of the surface 4A of each magnet holder 4.

  Next, the magnet 3 is placed on each surface 4A of the plurality of magnet holders 4 coated with the adhesive (S3). The placement of the magnet 3 may be performed manually or using an apparatus.

  Next, the jigs 10 are respectively placed on the plurality of magnet holders 4 (S4). Specifically, as described above, each of the magnets is inserted by inserting the end on the surface 4A side on which the magnet 3 of each magnet holder 4 is placed and the second hole 2A of the jig 10. The jig 10 is put on the holder 4 (see FIGS. 4 and 5).

  Next, the tray 12 is placed in a high temperature environment (S5). Specifically, as shown in FIG. 7, a tray 12 on which a plurality of magnet holders 4 covered with a jig 10 are placed is placed in an adhesive curing oven, and the oven is necessary for curing the adhesive. Temperature (about 100 ° C. in the above example).

Thereafter, when a sufficient time has passed for the adhesive to harden, the tray 12 is taken out, and the jig 10 fitted in each magnet holder 4 is removed.
As described above, the magnet 3 can be fixed on the magnet holder 4.

  As described above, according to the magnet bonding method according to the present embodiment, the valve opening degree detection magnet can be bonded onto the valve shaft at a low cost. That is, by using the tray 12, a plurality of magnet holders 4 covered with the jig 10 can be collectively placed in a high-temperature environment such as an oven, so that it is a one-pack type adhesive that cures at a temperature higher than normal temperature. Even when the agent is used, the magnet 3 can be efficiently fixed to the plurality of magnet holders 4. Further, by using the tray 12, it is possible to use a one-component adhesive having a relatively lower viscosity than the two-component adhesive, and therefore, for example, an inexpensive air dispenser dispenser using air pressure is used. Can do.

  Moreover, by using the positioning jig 10, the positioning of the valve opening degree detection magnet can be performed with high accuracy and at low cost. That is, after the magnet 3 was placed on the magnet holder 4 coated with an adhesive, the magnet holder 4 was inserted into the first hole 2A of the jig 10 to form the taper of the jig 10. The position of the magnet 3 can be determined by the contact between the inner wall surface of the second hole 2B and the end 3A of the magnet 3. Thereby, the magnet 3 can be accurately arrange | positioned with respect to the magnetic sensor 6 by manual work, without using an expensive apparatus as mentioned above.

  As described above, according to the magnet adhesion method according to the present embodiment, the positioning of the valve opening degree detection magnet installed on the valve shaft and the adhesion of the valve opening degree detection magnet on the valve shaft can be improved. It can be performed with high accuracy and low cost. Therefore, by applying the magnet adhering method according to the present embodiment and manufacturing the flow control valve using the above-described magnetic sensor, the detection accuracy of the valve opening degree of the flow control valve can be improved. Therefore, it is possible to realize a flow control valve with high flow measurement accuracy at a lower cost.

  Further, since the third hole 2C is formed in the other end 1C of the base body 1 in the jig 10, the operator can place the magnet 3 during the work by the magnet bonding method according to the present embodiment. Since presence / absence or the like can be visually confirmed, it is possible to prevent the occurrence of work mistakes and improve work efficiency. Further, since the hole 2 becomes a through hole by the third hole portion 2C, the processing of the jig 10 itself is facilitated, which contributes to the reduction of the manufacturing cost of the jig 10.

  Although the invention made by the present inventors has been specifically described based on the embodiments, it is needless to say that the present invention is not limited thereto and can be variously modified without departing from the gist thereof. Yes.

  For example, in the above embodiment, the case where the adhesive is applied onto the magnet holder 4 after the plurality of magnet holders 4 are installed on the tray 12 is illustrated (see FIG. 7), but the present invention is not limited thereto. For example, after applying an adhesive to the plurality of magnet holders 4, the magnet holders 4 may be placed on the tray 12, or the jig 10 is attached to the magnet holder 4 on which the magnets 3 are placed via the adhesive. The magnet holders may be placed on the tray 12 after being covered.

Further, in the above-described embodiment, the case where the hole 2 is a through-hole is illustrated. However, when it is not necessary to consider jig processing or the like, as shown in FIG. The three holes 2C are not formed, and the hole 2 may not be a through hole.
When the third hole 2C is not formed, the second hole 2B may have a conical shape instead of a truncated cone shape.

  DESCRIPTION OF SYMBOLS 10,10A ... Jig, 1 ... Base | substrate, 1A, 1C ... End part of the base | substrate 1, 2 ... Hole, 2A ... 1st hole part, 2B ... 2nd hole part, 2C ... 3rd hole part, 3 ... Magnet, DESCRIPTION OF SYMBOLS 4 ... Magnet holder, 4A ... surface, 5 ... Valve shaft, 6 ... Magnetic sensor, 7 ... Board | substrate, 8 ... Housing | casing, 12 ... Tray, 12A ... Main surface, 120 ... Recessed part.

Claims (3)

An adhesion method for adhering a columnar magnet to a columnar magnet holder using a positioning jig comprising at least a part of a base formed in a cylindrical shape,
A first step of inserting one end of each of the plurality of magnet holders into a plurality of recesses formed on the main surface of the base;
A second step of applying a one-component adhesive that cures at a temperature higher than room temperature to each of the other ends of the plurality of magnet holders or the plurality of magnets;
A third step of placing the magnet on the other end of the magnet holder after the second step;
After the third step, a fourth step of fitting the other end of the magnet holder on which the magnet is placed into the opening of the cylindrical portion of the positioning jig;
And a fifth step of placing the base on which the plurality of magnet holders into which the positioning jigs are inserted are placed in a temperature environment in which the adhesive is cured. The bonding method according to claim 1,
The cylindrical portion of the positioning jig is
One end of the base is opened, and a cross section perpendicular to the axial direction of the base forms a cylindrical internal space having a diameter longer than the diameter of the magnet, and the outer periphery of the magnet holder on which the magnet is placed A first hole that fits into the surface with a clearance fit;
An internal space having a conical shape or a truncated cone shape coaxial with the first hole is formed, and a diameter of a cross section perpendicular to the axial direction of the base body in the internal space continuously decreases toward the other end of the base body. A bonding method comprising: a second hole portion. The bonding method according to claim 2,
The second hole has the truncated cone shape,
The base further includes a third hole that opens the other end of the base and forms a cylindrical inner space having a cross section perpendicular to the axial direction of the base that has a diameter shorter than the diameter of the magnet,
The inner wall surface of the second hole portion includes an end portion on the other end side of the base body on the inner wall surface of the first hole portion and an end portion on the one end side of the base body on the inner wall surface of the third hole portion. A bonding method characterized by being formed in a tapered shape.

Images