JP2019196799A - Opening/closing position setting structure of electric actuator for valve and its opening/closing position setting method - Google Patents

Abstract

To provide an opening/closing position setting structure of an electric actuator for a valve which can adjust an output shaft of the electric actuator for the valve to an opening/closing position of a stem of the valve, can accurately regulate the output shaft side into a full-closed state or a full-open state while preventing the enlargement of the actuator and the complication of an internal structure, can exactly and easily adjust a valve opening/closing state of the output shaft, and can singly adjust an opening/closing position of the actuator without using the valve, and its opening/closing position setting method.SOLUTION: An opening/closing position setting structure of an electric actuator for a valve comprises a rotary encoder 30 for measuring a rotation angle of a control shaft 22 arranged at an output shaft 4 coaxially therewith, and a jig 6 detachably fixed to a valve fixing position at the output shaft 4 side, and rotationally regulating the output shaft 4 to a valve opening/closing position. A state of a control shaft 22 when the rotation of the output shaft 4 is regulated by the jig 6 is measured by the rotary encoder 30, and the valve opening/closing position of the actuator is set.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a structure for setting an opening / closing position of an electric actuator for a valve, and more particularly to an opening / closing position setting structure suitable for setting an opening / closing position of a rotary valve such as a ball valve and an opening / closing position setting method thereof.

  Conventionally, when an electric actuator is mounted on a rotary valve such as a ball valve, it is necessary to adjust the operating angle of the valve stem connected to the output shaft of the electric actuator in order to accurately control the rotation of the valve. There is. In this case, generally, the output shaft of the actuator is adjusted so as to be in the fully open and fully closed positions of the valve so that when the actuator is driven, the valve is fully opened, fully closed, and the flow rate can be controlled to an arbitrary intermediate opening. It is possible.

  When setting the opening / closing position of such an actuator, adjustment is made using a contact-type position detection device using a micro switch and a cam, or a non-contact type position detection device using a rotary encoder such as an optical or magnetic type. In many cases, a technique for controlling the rotation angle of the output shaft using a stepping motor is also known.

Among these, in the case of position adjustment using a contact-type position detecting device, in order to accurately set the fully closed and fully opened stop positions, particularly time and man-hours are required for cam position adjustment. In addition, if the valve is used in an environment where a gas such as siloxane gas is generated, contact failure may occur due to the formation of an insulator on the contact part, oxidation of the contact part metal, or corrosion, resulting in inaccurate position detection. Therefore, there is a problem that the life is likely to be reduced.
On the other hand, when the rotation of the output shaft is controlled using a stepping motor, the overall size of the actuator is increased due to the mounting of the stepping motor, and the stepping motor is expensive, which is not general.
Compared to these, when using a non-contact type position detection device, a general-purpose DC motor was used to configure the actuator while ensuring the overall compactness, and the problem of the contact type position detection device was solved. The rotation control of the output shaft is possible in this state.

As an example of controlling the rotation of a valve using this type of non-contact type position detection device, for example, a valve actuator in Patent Document 1 is disclosed. This valve actuator fully-closed position setting device uses a non-contact rotary encoder as the position detection device. This rotary encoder measures the rotation angle of the output shaft and corrects the angle deviation when the valve is fully closed. By doing so, the opening angle of the valve is made closer to the command angle.
Thus, when the output shaft of the actuator is rotationally controlled by the rotary encoder, it is necessary to adjust the output shaft on which the rotary encoder is installed to the open / close state of the valve stem.

JP 2002-276838 A

  However, in the case of the actuator of Patent Document 1, when the output shaft is adjusted to the fully closed / open state, a valve stem in a state where the rotation is not restricted is connected to the output shaft. And it is designed to rotate beyond the fully open position. For this reason, it is necessary to adjust the actuator to the valve open / close position via the output shaft while accurately adjusting the stem to the open / closed state, and it takes time and effort to set it accurately.

In addition, the output shaft rotation is deviated due to backlash of the reduction gear train in the actuator, or when the DC motor is used as power, the armature's moment of inertia increases or the motor itself rotates more. Since an overrun may occur during stoppage, the output shaft becomes more difficult to adjust and needs to be finely adjusted.
The above-mentioned position adjustment of the output shaft needs to be performed for each valve according to the valve type and individual differences of the valve, so each time the output shaft is connected to the stem with an actuator mounted on the valve. Will do.

  In addition, in the actuator of Patent Document 1, a rotary encoder for measuring an absolute angle called a so-called absolute type is used for measuring an output shaft. When this type of encoder is used, fine adjustment is required to zero-align the output shaft, which complicates the internal structure of the actuator and increases the size of the entire actuator.

When the absolute type is used, an optical rotary encoder is often used to set the output shaft with high accuracy and high resolution. This optical rotary encoder is used for contamination of products such as gas, dust and oil. This makes it difficult to make fine adjustments, and in order to increase the resolution, the optical system and internal mechanism become complicated, leading to an increase in the size and cost of the entire encoder.
On the other hand, even if an attempt is made to use a magnetic rotary encoder that is simpler than the optical type, the accuracy is inferior to that of the optical type, making it difficult to set the fully closed and fully open positions of the actuator output shaft. Also gets longer.

  The present invention has been developed in order to solve the conventional problems. The object of the present invention is a setting structure that adjusts the output shaft of the valve electric actuator to the open / close position of the valve stem. The output shaft side can be adjusted to the fully closed or fully open state with high accuracy, and the valve open / closed state of the output shaft can be adjusted accurately and easily without the need for a valve. It is an object of the present invention to provide an open / close position setting structure and an open / close position setting method for an electric actuator for a valve that can adjust the open / close position by an actuator alone.

  In order to achieve the above object, the invention according to claim 1 is directed to an actuator in which the rotation of the electric motor is transmitted to the output shaft via the reduction gear train, and the valve stem is connected to the output shaft of the actuator. An open / close position setting structure for setting the open / close position of the driven valve, and a rotary encoder for measuring the rotation angle of the control shaft provided coaxially with the output shaft, and a fixed position of the valve on the output shaft side. A jig that is detachably fixed and restricts the rotation of the output shaft to the valve opening / closing position is provided. When the rotation of the output shaft is restricted by this jig, the state of the control shaft is measured by a rotary encoder, and It is an opening / closing position setting structure of the electric actuator for valves in which the valve opening / closing position is set.

  In the invention according to claim 2, the jig has a protrusion that can be inserted into a female screw for fixing the valve formed on the actuator, and the valve is fixed to the valve mounting position of the actuator via the protrusion. FIG.

  In the invention according to claim 3, the jig has a mounting member for mounting to the actuator, and a rotating member that rotates with respect to the regulation groove formed in the mounting member is mounted. It has a fitting part that is concavo-convexly fitted into a concave groove formed at the end of the shaft and rotates coaxially with the output shaft, and the restriction part that protrudes in the centrifugal direction of this fitting part is a valve of the restriction groove This is an opening / closing position setting structure of the valve electric actuator provided in a state where it abuts at the opening / closing position and regulates the output shaft to the rotation angle of the stem.

  The invention according to claim 4 is the open / close position setting structure of the electric actuator for valves in which the restriction groove is formed at approximately 90 ° or approximately 180 °.

  According to the fifth aspect of the present invention, the rotary encoder has a non-contact encoder IC, and the open / close position of the electric actuator for the valve in which the detected body is integrally mounted on the upper end side of the control shaft facing the encoder IC. It is a setting structure.

  The invention according to claim 6 is an opening / closing operation between an actuator in which the rotation of the electric motor is transmitted to the output shaft via the reduction gear train, and a valve that is driven to rotate by connecting the stem of the valve body to the output shaft of the actuator. An open / close position setting method for setting a position, wherein a rotary encoder for measuring the rotation angle is provided on a control shaft provided coaxially with the output shaft, and the output shaft is set to a valve fixed position on the output shaft side. An electric actuator for a valve in which a regulating jig is detachably fixed, and when the rotation of the output shaft is regulated with this jig, the state of the control shaft is measured with a rotary encoder, and the valve opening / closing position of the actuator is set This is an open / close position setting method.

  In the invention according to claim 7, the opening / closing position of the electric actuator for valves is set such that the jig is removed from the actuator, the valve is connected to the mounting position of the jig, and the stem of the valve is rotated coaxially with the output shaft. Is the method.

  The invention according to claim 8 is the open / close position setting method of the electric actuator for valves, wherein the rotation of the output shaft is decelerated immediately before the output shaft is regulated by the jig.

  According to the first aspect of the present invention, the output shaft of the electric actuator for the valve can be adjusted to the open / close position of the valve stem using the rotary encoder and the jig, and the enlargement of the actuator and the complexity of the internal structure are prevented, With the output shaft fully closed or fully open, the rotation of the control shaft coaxial with this output shaft is measured with a rotary encoder and output via a jig fixed at the valve fixing position on the output shaft side. Adjustment of the valve open / close state of the shaft can be performed accurately and easily. In this case, since the rotation of the output shaft is regulated by the jig, the opening / closing position can be adjusted by the actuator alone without being mounted on the valve.

  According to the second aspect of the present invention, the protrusion is inserted into the female screw for fixing the valve so that the output shaft of the actuator can be rotated by this jig while the jig is fixed at the valve fixing position of the actuator. Can be regulated. For this reason, the output shaft can be accurately regulated to the opening / closing angle of the valve fixed to the female screw, and the opening / closing state of the output shaft can be adjusted by the rotary encoder.

  According to the invention of claim 3, the rotating member rotates in the restricting groove of the mounting member, and the fitting portion of the rotating member engages with the concave groove of the output shaft of the actuator, while the restricting portion is the valve of the restricting groove. By restricting the output shaft to the rotation angle of the stem by abutting at the open / close position, the output shaft can be forcibly and accurately matched to the open / closed state of the valve simply by mounting a jig, and the output shaft can be made highly accurate. Can be aligned.

  According to the invention of claim 4, the output shaft can be accurately adjusted according to the fully closed and fully open positions of the two-way ball valve without mounting the valve by providing the restriction groove at approximately 90 °, By providing the restriction groove at approximately 180 °, the output shaft can be switched in accordance with the flow path of the three-way switching type ball valve.

  According to the invention of claim 5, by using a rotary encoder having a non-contact rotary encoder and a detected object, the configuration can be simplified and the whole can be made compact, and this gas can be produced even in a gas generation environment. The position can be detected in a state in which the adverse effects of are suppressed, and the opening and closing can be accurately controlled over a long period. The detected object is a magnet, the encoder IC is a magnetic encoder IC, and the output shaft is zeroed by adopting an incremental type that detects the relative angle between the magnet-mounted control shaft and the magnetic encoder IC. In addition, since it is possible to automate the operation by adjusting the opening / closing position, the number of adjustment steps can be greatly reduced, and the manufacture is facilitated. While miniaturizing the rotary encoder, it can be finely adjusted and accurately controlled for opening and closing.

  According to the invention of claim 6, the output shaft of the electric actuator for the valve can be adjusted to the opening / closing position of the valve stem using a rotary encoder and a jig, while preventing the actuator from becoming large and the internal structure from being complicated, Adjustment of the valve open / closed state of the output shaft can be performed accurately and simply in a state where the output shaft is highly accurately regulated to the fully closed or fully opened state via the jig. In addition, the jig can be easily attached to and detached from the actuator, and by controlling the rotation of the output shaft with this jig, the opening / closing position can be adjusted by the actuator alone without being mounted on the valve.

  According to the seventh aspect of the present invention, after the fully open and fully closed positions of the actuator output shaft are accurately adjusted using a jig, a valve is connected to accurately transmit the rotation amount from the output shaft through the stem. Thus, the opening / closing position can be controlled with high accuracy. A single jig can be used to set the valve opening / closing positions of a large number of actuators, and the jig can be easily attached and detached, so that the setting work is facilitated.

  According to the eighth aspect of the present invention, it is possible to prevent wear and damage of internal parts such as the output shaft and jigs, and to control the open / close position of the valve accurately.

It is a perspective view which shows the state before mounting | wearing an actuator with a jig | tool. (A) is a principal part expansion perspective view of FIG. (B) is a perspective view which shows the state which mounted | wore the jig | tool. (A) is a perspective view which shows the jig | tool in FIG. (B) is a perspective view which shows the other example of a jig | tool. It is a circuit block diagram of an actuator. (A) is a partially cutaway front view showing a state where the cover of the actuator is removed. (B) is the principal part enlarged view of (a). It is a schematic diagram which shows the operation state of a magnetic encoder. It is a front view which shows the state which mounted the actuator in the valve | bulb.

Embodiments of an opening / closing position setting structure and an opening / closing position setting method for an electric actuator for a valve according to the present invention will be described below in detail with reference to the drawings.
FIG. 1 shows a state before the jig is mounted on the actuator, and FIG. 2 shows an enlarged view of the main part near the jig mounting portion. The present invention is an open / close position setting structure for setting an open / close position between an actuator and a valve rotated by the actuator, and accurately sets the open / close position of the actuator using a jig.

  In FIG. 1, a valve electric actuator (hereinafter referred to as an actuator) 1 has an electric motor 2, a reduction gear train 3, an output shaft 4, a control board 5, and a cover 7 for covering the inside. A jig 6 is attached. The output shaft 4 is provided with a stem 12 of a valve body 11 of a valve 10 made of a ball valve so as to be connectable.

  In FIG. 5, the actuator 1 has a circular frame-shaped base 15, the reduction gear train 3 is accommodated in the base 15, and a disk-like partition plate 16 is attached above the reduction gear train 3. In addition, columnar spacers 17 are erected at a plurality of positions from the upper surface of the partition plate 16 at appropriate intervals, and the substrate 5 is fixed to the spacers 17. Thereby, the substrate 5 is arranged at a predetermined interval from the partition plate 16. As shown in FIG. 1, two female screws 14 for fixing the mounting flange 13 of the valve 10 of FIG. 7 with screws 19 are provided on the bottom surface of the base 15 at a predetermined interval.

  The electric motor 2 is a DC (direct current) brushless motor having a general structure, and is fixed to the upper surface of the partition plate 16. When the electric motor is a DC brushless motor, there is no mechanically slidable contact portion, and the generation of insulators is suppressed by avoiding the generation of sparks and arc discharge during rectification, and dead points during operation are prevented. As a result, the output shaft whose opening / closing position is adjusted can be rotated with high accuracy within the rotation range, and a highly reliable electric valve can be provided. In addition, the insulation is prevented from lowering and the operation is maintained with high accuracy over a long period of time. A cable 18 can be connected to the electric motor 2 from the outside of the actuator 1, and a voltage is supplied from an external power source (not shown) through the cable 18 and the control board 5 to rotate.

  In FIG. 5, the reduction gear train 3 has an input shaft (not shown) and an output shaft 4. The rotation from the electric motor 2 is input to the input shaft, and the torque is amplified by the reduced rotation to the output shaft 4. Transmitted in state.

The output shaft 4 is provided so as to protrude from the bottom surface of the base 15, and a concave groove 20 is formed at the lower end thereof. The concave groove 20 is provided with a parallel two-surface portion 21 formed at the upper end of the stem 12 of the valve 10 so that the concave groove 20 and the parallel two-surface portion 21 are concavo-convexly fitted to the output shaft 4. The stem 12 is connected. With these connections, the rotation of the electric motor 2 decelerated by the reduction gear train 3 is transmitted from the output shaft 4 to the stem 12, and the valve body 11 connected to the stem 12 is driven to rotate.
At that time, the opening / closing position between the output shaft 4 of the actuator 1 and the valve 10 is set by the actuator opening / closing position setting structure of the present invention.

  The output shaft 4 is provided with a control shaft 22 coaxially, and the control shaft 22 rotates integrally with the output shaft 4. The control shaft 22 is arranged so that the upper end side protrudes from the partition plate 16 and faces the substrate 5, and a rotary encoder 30 is provided between the substrate 5 and the control shaft 22.

  The rotary encoder 30 is provided for measuring the rotation angle of the control shaft 22 (output shaft 4). In this example, the rotary encoder 30 is a non-contact magnetic type, and is detected by a non-contact magnetic encoder IC 31 and this encoder IC. It has a magnet 32 which is an object to be detected. The rotary encoder is not limited to the magnetic type as long as it is a contact type, and for example, an optical type may be used.

  5 and 6, the encoder IC 31 is disposed on the side of the substrate 5 facing the control shaft 22, and information that can detect the rotation angle of the magnet (detected body) 32 is recorded. The magnet 32 is made of, for example, a substantially cylindrical permanent magnet having a diameter of about φ8 mm to φ10 mm. The N pole and the S pole are magnetized in two directions in the thickness direction, and a holding holder 33 is provided on the upper end side of the control shaft 22. Is attached.

  As shown in FIG. 5B, the holder 33 is formed in a substantially cylindrical shape, and notch grooves 34 are provided alternately along the axial direction at the upper and lower portions of the holder 33, and the holder 33 is formed by the notch grooves 34. Is provided so as to be capable of expanding and contracting in the radial direction. The holder 33 is fixed to the upper end portion of the control shaft 22 with the magnet 32 attached to the upper portion of the holder 33 through the notch groove 34. When the magnet 32 is attached to the control shaft 22 at an arbitrary magnetization angle via the holder 33 and the control shaft 22 rotates, the magnet 32 rotates integrally with the control shaft 22. The magnets are arranged facing each other with a gap of about several millimeters from the encoder IC31.

  The rotation angle of the control shaft 22 (output shaft 4) is detected from a hall element (not shown) arranged inside the encoder IC 31 by interlinking the leakage magnetic flux due to the N pole and S pole of the magnet 32 to the encoder IC 31. After obtaining an angle analog signal by performing vector operation continuously from the output voltage of the output voltage, the angle analog signal is converted into a digital signal.

  In this case, the angle analog signal of the encoder IC 31 is transmitted to the MPU through a copper foil pattern on the substrate to the MPU by high-speed serial communication, thereby obtaining accurate rotation angle data of the output shaft.

  In this way, the absolute value of the output opening of the actuator 1 is obtained as a digital value by taking the rotation of the magnet 32 of the control shaft 22 as a signal into the MPU (Central Processing Unit) 40 described later via the encoder IC 31. Thus, the rotation state of the control shaft 22 is measured. The magnet 32 described above is attached by the holder 33 so as to coincide with the axis of the control shaft 22 (output shaft 4), and rotates coaxially with the control shaft 22 (output shaft 4). By measuring the rotation of the magnet 32 with a non-contact encoder IC 31, an electronic non-contact state is obtained and contact failure is prevented.

  In this way, in the relationship between the encoder IC 31 and the magnet 32 shown in FIG. 6, for example, any control shaft 22 (magnet 32) from FIG. 6 (a) to FIG. The encoder IC31 can measure with high accuracy. 6 (a), 6 (b), 6 (c), and 6 (d) show the polarities of the magnet 32 when the control shaft 22 rotates 0 °, 90 °, 180 °, and 270 °, respectively. In the case where the valve 10 is a 90 ° open / close type two-way ball valve, FIG. 6 (a) may be closed and FIG. 6 (b) may be opened. In the case of a three-way ball valve, the rotation state can be measured by the polarity of the magnet 32 when the control shaft 22 rotates 180 ° from FIG. 6 (a) to FIG. 6 (c).

  1 to 3, the jig 6 includes an attachment member 41 for attachment to the actuator 1 and a rotation member 42 that is rotatably attached to the attachment member 41.

  The attachment member 41 is formed in a compact rectangular shape, and two small cylindrical protrusions 43 are formed on the attachment side to the actuator 1. The protrusion 43 is formed at a position corresponding to the two female screws 14 for fixing the valve 10 of the actuator 1 (base 15), and is provided so as to be insertable into the female screw 14. The jig 6 can be fixed to the predetermined valve mounting position of the actuator 1 in a state where displacement is prevented, by inserting the protrusion portion into the 43 female screw 14.

  On the attachment surface side of the attachment member 41, a regulation groove 45 having a substantially fan shape and a bottom is formed. In FIG. 3A, the regulation groove 45 is formed at 90 ° or more including the opening / closing angle of the valve 10 or 90 ° including play at the time of opening / closing, and the rotating member 42 is attached to the regulation groove 45. Further, FIG. 3B shows another example of the regulation groove, and the regulation groove 46 shows a state where it is formed at 180 ° or 180 ° including play at the time of opening and closing.

  As described above, the restriction groove may be formed at approximately 90 ° or approximately 180 °, or may be formed at an angle other than these. A regulation end face 47 is formed on each end side of the regulation groove 45 in FIG. 3A and the regulation groove 46 in FIG. 3B, and the rotating member 42 can come into contact with each regulation end face 47. Yes.

  The rotating member 42 shown in FIG. 2 has a rotating shaft portion 50 and a fitting portion 51, and a rectangular fitting portion 51 is integrally formed at the end of the rotating shaft portion 50. The rotation shaft portion 50 is a rotation center when the rotation member 42 is attached to the restriction groove 45 (46), and is provided at a position coaxial with the output shaft 4. The fitting portion 51 is formed to have a width that can be concavo-convexly fitted into the concave groove 20 of the output shaft 4, and the rotating member 42 is coaxial with the output shaft 4 through the concavo-convex fitting of the fitting portion 51 and the concave groove 20. Mounted to rotate. In the centrifugal direction of the fitting portion 51, a restricting portion 52 is formed so as to protrude integrally with the fitting portion 51.

  The rotating member 42 is rotatably attached to the restricting groove 45 in a state where the fitting part 51 is mounted in the concave groove 20, and the restricting part 52 abuts on restricting end faces 47 and 47 that are valve opening / closing positions of the restricting groove 45. Thus, the output shaft 4 connected to the rotating member 42 is restricted by the rotation angle of the stem 12. Although not shown, the fitting portion 51 may be formed in a wedge shape. In this case, the fitting portion 51 is fitted so as to bite into the concave groove 20, and the rotating member 42 is loose with respect to the output shaft 4. Rotates as a unit in the absence.

  1 to 3, the jig 6 is detachably fixed to the fixing position of the valve 10 on the output shaft 4 side by inserting the protrusion 43 into the female screw 14. In this state, the output shaft 4 is connected to the valve 10. The rotation is restricted to the open / close position. The jig 6 is used to forcibly restrict the rotation of the output shaft 4 to a predetermined opening / closing state, and the rotation state of the control shaft 22 at this time is measured by the rotary encoder 30, thereby setting the valve opening / closing position of the actuator 1. It can be set.

  4, in addition to the encoder IC 31, the substrate 5 described above includes a motor drive circuit 60, a motor regenerative braking circuit 61, a motor torque control circuit 62, an automatic angle setting function selection switch 63, an input / output interface circuit 64, a power supply circuit. 65 and a mode setting circuit 66 are provided, and these are respectively connected to the MPU 40 described above.

  The MPU 40 is connected to a circuit on the substrate 5 and controls the entire actuator 1. An EEPROM 70 is built in the MPU 40, and control angle data for controlling the control shaft 22 to a predetermined opening / closing angle is stored (recorded) in the EEPROM 70.

  The motor drive circuit 60 is connected to the electric motor 2 as a circuit for driving the electric motor 2. The motor regenerative braking circuit 61 is provided for applying braking to the electric motor 2. By combining this motor regenerative braking circuit 61 with the encoder IC 31 and the DC brushless motor (electric motor) 2 having a low moment of inertia, it is possible to detect the position with high accuracy while suppressing the coasting amount, and the torque at the time of rotating the stem 12 The valve 10 is stably operated in a tight shut and full open operation without being affected by the increase / decrease change.

  The motor torque control circuit 62 controls the reduction gear train 3, the output shaft 4, the electric motor 2, the motor drive circuit 60, and the power supply circuit when the jig 6 restricts the output shaft 4 to the rotation range from the fully closed position to the fully opened position. In order to suppress the stress to 65, it is provided for reducing the maximum output torque value of the electric motor 2. On the other hand, when it is not necessary to restrict the rotation when the jig 6 is not mounted, the current is limited in order to suppress the generation of torque exceeding the allowable maximum torque value of the actuator 1.

  The automatic angle setting function selection switch 63 has a function of switching the automatic angle of the actuator 1. In this embodiment, the switch 63 can be switched to each mode of “automatic angle setting mode” or “normal operation mode”, and the flow of firmware (software) provided in the MPU 40 is switched. Each mode can be selected. The “automatic angle setting mode” is an operation mode used when the opening / closing position of the output shaft 4 is set by the opening / closing position setting method of the actuator 1, while the “normal operation mode” is the actuator 1 after setting the opening / closing position. The operation mode when the valve 10 is attached to the valve 10 and the valve 10 is normally controlled to be opened and closed is shown.

  The input / output interface circuit 64 is provided to match the opening / closing command input signal and the opening / closing output signal of the actuator 1 with the user circuit. The power supply circuit 65 is provided to supply power by matching power supplied from a power supply terminal (not shown) with specifications of a motor power supply and a control power supply used in the actuator 1. The mode setting circuit 66 is provided for setting a mode when the actuator 1 is opened and closed by 180 °.

Next, a method for setting the open / close position of the electric actuator for valves and the operation thereof will be described.
1 to 5, when the opening / closing position of the actuator 1 is set to the operating angle of the valve 10 composed of a 90 ° opening / closing ball valve, a rotary encoder 30 (encoder IC 31, a detected object 32 including a magnet) is connected to the control shaft 22. ), A jig 6 is fixed at a valve fixing position on the output shaft 4 side, and the control shaft 22 rotating integrally with the output shaft 4 regulated by the jig 6 is measured by the rotary encoder 30 to thereby measure the valve. Set the open / close position.

  In this case, a low torque drive mode is set by the motor torque control circuit 62, and the rotation of the output shaft 4 is decelerated immediately before the rotation of the output shaft 4 by the jig 6 in this low torque drive mode. . In this way, the torque of the electric motor 2 is reduced, and in this state, the restricting portion 52 of the rotating member 42 connected to the output shaft 4 (control shaft 22) is brought into contact with the restricting end surface 47 to restrict the position. It becomes possible to adjust to the reliability. The procedure of the opening / closing position setting method will be described in detail below.

  When the opening / closing angle of the actuator 1 is set, the following (1) to (12) are performed according to the “automatic angle setting mode” described above.

(1) The automatic angle setting function selection switch 62 is switched to the “automatic angle adjustment mode” in a state where the external power supply is turned off and no voltage is supplied.

(2) With the actuator 1 turned upside down, the projections 43 and 43 are respectively inserted into the two female screws 14 and 14 while the fitting portion 51 is concavo-convexly fitted into the concave groove 20 and The jig 6 is fixed to the bottom surface of the table 15 in a predetermined direction. Accordingly, the rotation of the output shaft 4 (control shaft 22) can be restricted by the jig 6.

(3) When the external power supply is turned on in this state, the software provided in the MPU 40 switches to the “automatic angle adjustment mode” and at the same time, the motor torque control circuit 62 enters the low torque drive mode and the electric motor 2 is fully closed. Rotate in the direction.

(4) As the electric motor 2 rotates, the output shaft 4 rotates in the fully closed direction. When the restricting portion 52 of the rotating member 42 comes into contact with the restricting end surface 47 on the fully closed side of the restricting groove 45, the rotation is stopped and the output shaft 4 is fully closed. At this time, the reduction gear train 3, the output shaft 4, and the control shaft 22 are suppressed to rotate with a minimum torque by the low torque drive mode of the motor torque control circuit 62. For this reason, when the restricting portion 52 that rotates integrally with the output shaft 4 comes into contact with the restricting end surface 47, the reduction gear train 3, the output shaft 4, the control shaft 22, the electric motor 2, a motor drive circuit (not shown), and the like are damaged. There is no risk of failure.

(5) When the output shaft 4 stops at the fully closed position, the change of the angle data value by the encoder IC 31 stops. When this change stop state continues for a preset time, it is recognized as the fully closed position of the valve. This state is recorded in the EEPROM 70 in the MPU 40 as fully closed position data. Alternatively, a reset signal is sent to the encoder IC 31 to make the angle data zero, and this zero value is recorded in the EEPROM 70 as the fully closed position data.

(6) After recording the fully closed position, the electric current to the electric motor 2 is turned off and the rotation stops.

(7) Next, the electric motor 2 is rotationally driven in the fully open direction while maintaining the low torque drive mode by the motor torque control circuit 62.

(8) When the output shaft 4 rotates in the fully open direction and the restricting portion 52 of the rotating member 42 comes into contact with the restricting end surface 47 on the fully closed side, the rotation stops and the output shaft 4 enters the fully open state. In this case as well, the reduction gear train 3, the output shaft 4, and the control shaft 22 are restrained from rotating with a minimum torque by the low torque drive mode as in the fully closed direction. For this reason, even when the restricting portion 52 comes into contact with the restricting end surface 47, there is no possibility that the reduction gear train 3, the output shaft 4, the control shaft 22, the electric motor 2, the motor drive circuit, and the like are damaged or broken.

(9) When the output shaft 4 stops at the fully open position, the change of the angle data value by the encoder IC 31 stops, and when this change stop state continues for a preset time, it is recognized as the fully open position of the valve. Is recorded in the EEPROM 70 as fully open position data.

(10) After recording the fully open position, the electric power to the electric motor 2 is turned off and the rotation stops.

(11) With the above-described operation, the setting of the fully closed position / full open position of the output shaft 4 in the “automatic angle setting mode” is completed. After completion of these, the off state of the external power supply is confirmed, and the automatic angle setting function selection switch 63 is switched from the “auto angle setting mode” to the “normal operation mode”.

(12) Remove the jig 6 by lifting it from the actuator 1. At this time, the fitting portion 51 and the protruding portion 43 can be easily detached from the concave groove 20 and the female screw 14.

  After the opening / closing position of the actuator 1 is set, the valve 10 is fixed to the mounting position of the jig 6, the stem 12 of the valve 10 is connected to the output shaft 4, and these are rotated coaxially. Open and close. In this case, the valve operates in the operation mode of the “normal operation mode” described above. An example of the valve operation setting in the “normal operation mode” is shown in the following procedures (13) to (22).

(13) The external power supply is turned on, the rotation direction of the electric motor 2 is determined according to the opening / closing command, and the actuator 1 is operated in a state where the duty is 100%.

(14) The angle data value from the encoder IC 31 at this time is sequentially read by the MPU 40.

(15) When the open / close command is a command in the fully open direction, the fully open position data recorded in the EEPROM 70 is compared with the angle data read value from the encoder IC 31, and several% (for example, 3% to 5%) of the fully open position data. ) The energization rate to the electric motor 2 is reduced by the PWM control of the motor drive circuit 60 in front, and the energization is stopped and the motor regenerative braking circuit 61 applies the brake when it becomes 0.5% or less of the fully opened position data. To.
At this time, if the angle data read value exceeds the fully open position data of the EEPROM 70, the electric motor 2 is reversely rotated in the closing direction, and the energization is stopped when it falls within + 0.5% of the fully open position data. At the same time, braking is applied by the motor regenerative braking circuit 61.

(16) When the angle data read value becomes 93% or more of the full open position data of the EEPROM 70, the input / output interface circuit 64 outputs a full open signal as an open / close output signal. The threshold value 93% at this time is changed by firmware setting or DIP switch setting (not shown). As described above, since the angle data read by the rotary encoder 30 is constantly monitored and a signal is output in comparison with a preset threshold value, the expandability can be exhibited and the threshold value can be arbitrarily set. become.

(17) In the command operation in the opening direction, the fully open position data of the EEPROM 70 is compared with the angle data read value by the encoder IC 31, and the ± of the fully open position data is ± even if a preset time (for example, opening / closing time × 1.5) elapses. If it does not fall within 0.5%, the power supply to the electric motor 2 is turned off and an error signal is output from the input / output interface circuit 64.

(18) On the other hand, when the opening / closing command in the procedure (15) is a full-close command, the full-close position data recorded in the EEPROM 70 is compared with the angle data read value from the encoder IC31, and the percentage of the full-close position data ( (For example, 3% to 5%) The energization rate to the electric motor 2 is reduced by the PWM control of the motor drive circuit 60 just before the energization is stopped and the motor regenerative braking is stopped when it becomes 0.5% or less of the fully closed position data. The circuit 61 applies braking.
At that time, if the angle data read value exceeds the fully closed position data of the EEPROM 70, the electric motor 2 is rotated in the reverse direction in the open direction and is within -0.5% of the fully closed position data. The energization is stopped and braking is applied by the motor regenerative braking circuit 61.

(19) When the angle data read value becomes 7% or less of the fully closed position data of the EEPROM 70, the input / output interface circuit 64 outputs a fully closed signal as an open / close output signal. The threshold value 7% at this time is changed by firmware setting or DIP switch setting.

(20) In the command operation in the closing direction, the fully closed position data of the EEPROM 70 is compared with the angle data read value by the encoder IC 31, and the fully closed position data is passed even if a preset time (for example, opening / closing time × 1.5) elapses. If it does not fall within ± 0.5% of the above, the power supply to the electric motor 2 is turned off and an error signal is output from the input / output interface circuit 64.

(21) Here, when the jig 6 having the restriction groove 46 of about 180 ° in FIG. 3B is used to stop the opening / closing at 180 ° or the intermediate opening, the mode setting circuit 66 operates. Set the mode. When setting to the intermediate opening, the central value of the full-open / full-closed position data recorded in the EEPROM 70 is newly recorded and set in the EEPROM 70 as intermediate position data, and the firmware routine is switched so that it can also stop at the intermediate position. Correspond.

(22) In the intermediate position command operation, the intermediate position data recorded in the EEPROM 70 and the angle data read value by the encoder IC 31 are compared, and even if a preset time (for example, opening / closing time × 1.5) has elapsed, the intermediate position If it does not fall within ± 0.5% of the data, the power supply to the electric motor 2 is turned off and an error signal is output by the input / output interface circuit 64.

  The open / close position setting structure of the electric actuator for valve according to the present invention includes a rotary encoder 30 on the control shaft 22 side provided coaxially with the output shaft 4, and a base of the valve fixing position on the output shaft 4 side connected to the stem 12. When the jig 6 is fixed via 15 female screws 14 and the rotation of the output shaft 4 is restricted by the jig 6, the state of the control shaft 22 is measured by the rotary encoder 30 to set the valve opening / closing position. Therefore, the valve opening / closing position of the output shaft 4 can be adjusted by the actuator 1 alone without using a microswitch or a cam.

  In this case, the rotary encoder 30 has a non-contact encoder IC 31 and a magnet 32, the encoder IC 31 is mounted on the substrate 5, and the magnet 32 is opposed to the encoder IC 31 using a holder 33 at the upper end of the control shaft 22. By mounting them integrally, they can be arranged without contacting them, and can be attached easily and accurately while reducing the number of adjustment steps. For this reason, it is possible to extend the long life, and to prevent the illegal generation of the output signal due to the phenomenon that the contact point of the microswitch is located at the neutral point.

  By using the encoder IC 31 and the magnet 32 of φ8 mm to φ10 mm, the rotary encoder 30 that is miniaturized is configured, and the height of the actuator 1 is kept low, contributing to the overall compactness.

  By arranging a set of encoder IC 31 and magnet 32 by surface mounting, the number of parts can be reduced, and complicated wiring is not required in the actuator 1, and these are arranged with fine positioning and adjustment. There is no need.

Since the voltage to the electric motor 2 can be turned on and off by a semiconductor (MOS_FET, power transistor) switch in the motor drive circuit, arc discharge by the mechanical contact part is prevented, and the contact part of each part is worn due to increased contact resistance or heat generation. It is possible to eliminate malfunctions caused by melting, fine welding, and the like. In addition, by avoiding dissolution of the electrode, there is no metal transition at the contact portion, and the occurrence of return failure (rocking) is also prevented.
Furthermore, even when a gas such as a sulfide gas exists in the environment where the actuator 1 is used, an insulator is not generated and adhered to the contact portion.

  As described above, since the encoder IC 31 and the magnet 32 are not in contact with each other, even when the actuator 1 is disposed in an environment where vibrations and impacts are likely to occur, such as a vehicle, damage, contact failure, and malfunction can be prevented. Long life can be achieved. Since the side pressure for detecting the rotation is not applied to the control shaft 22, there is no possibility that the rotation angle of the output shaft 4 is changed by suppressing the backlash of the control shaft 22 even after long-term use.

  Regardless of whether the valve 10 is a two-way ball valve that opens and closes 90 ° or a three-way ball valve that rotates 180 °, it can be easily handled by mounting the corresponding jig 6 on the actuator 1. The required control angle of the valve can be set by simply using the jig 6 having a different regulating groove when adjusting the angle in the “automatic angle setting mode” by the mechanism, hardware, and firmware. Furthermore, if the angle of the restricting groove is changed, it can be set to an arbitrary operation angle, so that versatility is high.

  The electric actuator described above may be mounted on a valve other than the ball valve to set the open / close position. For example, when the open / close position is set on a butterfly valve, the size or valve blade difference value may be set. If a jig having different restriction grooves is prepared in advance according to different specifications such as, the opening / closing position can be easily adjusted as in the case described above.

  The present invention is particularly effective for an actuator that operates with a general-purpose motor other than an actuator that uses a high-precision motor such as a stepping motor, and uses a nonvolatile memory such as an EEPROM for storing control angle data. Then, the valve opening / closing position can be accurately set as in the case of using the stepping motor while having a simple structure.

  In the above embodiment, the rotary encoder is used to measure the rotation state of the output shaft (control shaft). However, for example, a device that measures the rotation angle of the output shaft such as a gyro sensor may be used.

  The embodiment of the present invention has been described in detail above, but the present invention is not limited to the above-described embodiment, and the scope does not depart from the spirit of the invention described in the claims of the present invention. Thus, various changes can be made.

1 Electric actuator for valve 2 DC brushless motor (electric motor)
3 Reduction gear train 4 Output shaft 6 Jig 10 Ball valve
11 Valve body 12 Stem 14 Female screw 20 Concave groove 22 Control shaft 30 Rotary encoder 31 Encoder IC
32 Magnet (Detected object)
41 Mounting member 42 Rotating member 43 Protruding part 45 Restricting groove 51 Fitting part 52 Restricting part

Claims (8)

  Open / close position for setting the open / close position of an actuator in which the rotation of the electric motor is transmitted to the output shaft via the reduction gear train and the valve driven by the stem of the valve body connected to the output shaft of the actuator A rotary encoder for measuring a rotation angle of a control shaft provided coaxially with the output shaft; and a valve open / close position where the output shaft is detachably fixed to a fixed position of the valve on the output shaft side. A rotation restricting jig is provided, and when the rotation of the output shaft is restricted by the jig, the state of the control shaft is measured by the rotary encoder, and the valve opening / closing position of the actuator is set. An open / close position setting structure for an electric actuator for valves.   2. The jig according to claim 1, wherein the jig has a protrusion that can be inserted into a female screw for fixing a valve formed on the actuator, and is fixed to a valve mounting position of the actuator via the protrusion. Opening / closing position setting structure of electric actuator for valves.   The jig includes a mounting member for mounting to the actuator, and a rotating member that rotates with respect to a restriction groove formed on the mounting member is mounted. The rotating member is attached to an end of the output shaft. It has a fitting part that is concavo-convexly fitted into the formed concave groove and rotates coaxially with the output shaft, and the restriction part that protrudes in the centrifugal direction of the fitting part is at the valve opening / closing position of the restriction groove The open / close position setting structure of the electric actuator for valves according to claim 1, wherein the open / close position is set in a state where the output shaft is in contact with the stem and the stem is restricted to a rotation angle.   The opening / closing position setting structure of the electric actuator for valves according to claim 3, wherein the restriction groove is formed at approximately 90 ° or approximately 180 °.   5. The rotary encoder according to claim 1, wherein the rotary encoder has a non-contact encoder IC, and a detection target is integrally mounted on an upper end side of the control shaft so as to face the encoder IC. Opening / closing position setting structure of electric actuator for valves.   Opening / closing position setting method for setting an opening / closing position of an actuator in which rotation of an electric motor is transmitted to an output shaft via a reduction gear train and a valve driven by a stem of a valve body connected to the output shaft of the actuator A control shaft provided coaxially with the output shaft is provided with a rotary encoder for measuring a rotation angle thereof, and a jig for restricting the output shaft to a valve opening / closing position at a valve fixing position on the output shaft side. It is detachably fixed, and the state of the control shaft when the rotation of the output shaft is restricted by this jig is measured by the rotary encoder, and the valve opening / closing position of the actuator is set. Open / close position setting method for electric actuator for valves.   The opening / closing position of the electric actuator for valves according to claim 6, wherein the jig is removed from the actuator, a valve is connected to a mounting position of the jig, and a stem of the valve is rotated coaxially with the output shaft. Setting method.   The opening / closing position setting method of the electric actuator for valves according to claim 6 or 7, wherein the rotation of the output shaft is decelerated immediately before the output shaft is regulated by the jig.

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