Magnetic pole position detection system, magnetic pole position detection method, and magnetic pole position detection program
The magnetic pole position detection system uses back electromotive force to stabilize and accurately detect the position of the movable magnetic pole in a self-holding solenoid by alternating current direction, addressing instability issues in existing methods.
Patent Information
- Application Number
- JP2024008586
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-01-24
- Publication Date
- 2025-08-05
AI Technical Summary
Existing methods for detecting the position of a movable magnetic pole in a solenoid cause vibrations and instability due to disturbances from on/off energization, leading to unstable operation.
A magnetic pole position detection system that uses back electromotive force generated in the solenoid coil to accurately detect the position of the movable magnetic pole while stabilizing the self-holding solenoid by alternating current direction for short periods.
Accurate detection of the magnetic pole position is achieved while maintaining stable operation of the self-holding solenoid, reducing power consumption and minimizing disturbances.
Smart Images
Figure 2025114113000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a magnetic pole position detection system, a magnetic pole position detection method, and a magnetic pole position detection program for detecting the position of a movable magnetic pole in a solenoid. [Background technology]
[0002] Solenoids are commonly known as functional components that convert electrical energy into mechanical motion by using electromagnetic force to operate a movable magnetic pole (plunger). Because solenoids are actuators with extremely excellent responsiveness, they are used in a variety of applications, including automobiles, home appliances, office equipment, and electronic locks.
[0003] One type of solenoid is known as a self-holding solenoid. In this self-holding solenoid, when the solenoid coil is energized, the movable magnetic pole is attracted to the fixed magnetic pole, and after attraction, the attracted state of the movable magnetic pole is maintained by a permanent magnet. As a result, while the movable magnetic pole is attracted and held by the permanent magnet, there is no need to energize the solenoid coil, which reduces heat generation from the solenoid coil and achieves extremely high energy-saving performance.
[0004] In the self-holding solenoid described above, in order to ensure accurate operation of the equipment in which the solenoid is used, it is necessary to constantly monitor whether the moving magnetic pole is positioned in an attracted position where it is attached to the fixed magnetic pole, or in a disengaged position where it is disengaged from the fixed magnetic pole. In other words, if for some reason the moving magnetic pole cannot be attracted or disengaged when current is applied to the solenoid coil, the solenoid will remain in an abnormal state. Therefore, there is a need to detect the state of the moving magnetic pole, and measures such as installing a sensor to detect the position of the moving magnetic pole are required. However, this can lead to problems such as increased device complexity, increased costs, and increased installation space.
[0005] Therefore, there is a method in which a current is applied to a solenoid coil for a short time and the position of the movable magnetic pole is detected from the response waveform of the current flowing through the solenoid coil at that time, as described in Patent Document 1. By using the method described in Patent Document 1, it is no longer necessary to provide a separate component such as a sensor for detecting the position of the movable magnetic pole, and the position of the movable magnetic pole can be detected accurately using a simple method. [Prior art documents] [Patent documents]
[0006] [Patent Document 1] Japanese Patent Application Publication No. 4-196203 Summary of the Invention [Problem to be solved by the invention]
[0007] However, when detecting the position of a movable magnetic pole by short-time energization as described in Patent Document 1, the on / off of energization can cause disturbances, causing the solenoid to vibrate and resulting in unstable operation of the solenoid. [Means for solving the problem]
[0008] Therefore, the present invention provides a magnetic pole position detection system, a magnetic pole position detection method, and a magnetic pole position detection program that can accurately detect the position of a magnetic pole using the back electromotive force generated in a solenoid coil while stably operating a self-holding solenoid.
[0009] A magnetic pole position detection system according to one aspect of the present invention is a self-holding solenoid in which a movable magnetic pole and a fixed magnetic pole are placed in an attracted position by energizing a solenoid coil in a forward direction, which is a magnetization direction of the permanent magnet, and then the attracted position is maintained by the permanent magnet, and the movable magnetic pole is released from the permanent magnet by energizing the solenoid coil in a reverse direction, which is a demagnetization direction of the permanent magnet, and the movable magnetic pole and the fixed magnetic pole are placed in a released position. The magnetic pole position detection system detects the position of the movable magnetic pole in the self-holding solenoid, and includes: a drive circuit that supplies a drive current to the solenoid coil to drive the solenoid coil so that the movable magnetic pole and the fixed magnetic pole are placed in the attracted position and the released position; a drive control device that controls the drive circuit; and a position detection device that detects the position of the movable magnetic pole, and the drive control device energizes the solenoid coil in the forward direction for a predetermined first time period. a release-side basic drive unit that applies current to the solenoid coil in the reverse direction for a predetermined second time period, thereby placing the movable magnetic pole and the fixed magnetic pole in the release position; an attraction-side short-time drive unit that, after the supply of current to the solenoid coil in the forward direction for the first time period has stopped, applies current to the solenoid coil in the forward direction for a predetermined third time period that is shorter than the first time period; and a release-side short-time drive unit that, after the supply of current to the solenoid coil in the reverse direction for the second time period has stopped, applies current to the solenoid coil in the reverse direction for a predetermined fourth time period that is shorter than the second time period. The position detection device detects the relative position of the movable magnetic pole and the fixed magnetic pole based on the back electromotive force generated when the supply of current to the solenoid coil by the attraction-side short-time drive unit and the release-side short-time drive unit has stopped.
[0010] In the above-mentioned magnetic pole position detection system, the position detection device may have a coil potential acquisition unit that acquires the potential at each end of the solenoid coil, a coil voltage calculation unit that calculates the voltage between both ends of the solenoid coil from the difference in potential at both ends of the solenoid coil, and a position calculation unit that calculates the relative position of the movable magnetic pole and the fixed magnetic pole from the voltage between both ends of the solenoid coil.
[0011] In the above-mentioned magnetic pole position detection system, the position detection device may have a coil potential acquisition unit that acquires the potential at each end of the solenoid coil, a coil potential addition calculation unit that calculates a sum of the potentials at both ends of the solenoid coil from the sum of the potentials at both ends of the solenoid coil, and a position calculation unit that calculates the relative position of the movable magnetic pole and the fixed magnetic pole from the sum of the potentials at both ends of the solenoid coil.
[0012] In the magnetic pole position detection system described above, the position detection device includes a coil potential acquisition unit that acquires the potential at each end of the solenoid coil, and a position calculation unit that calculates the relative position between the movable magnetic pole and the fixed magnetic pole from the potential at each end. When the solenoid coil is energized by the attraction side short-time drive unit, the position calculation unit may select the potential at the upstream end in the forward direction as the potential for calculation to calculate the relative position, and when the solenoid coil is energized by the release side short-time drive unit, select the potential at the upstream end in the reverse direction as the potential for calculation.
[0013] A magnetic pole position detection method according to one aspect of the present invention is a self-holding solenoid in which a movable magnetic pole and a fixed magnetic pole are brought into an attracted position by energizing a solenoid coil in a forward direction, which is a magnetization direction of the permanent magnet, and then the attracted position is maintained by the permanent magnet, and the movable magnetic pole is released from the permanent magnet by energizing the solenoid coil in a reverse direction, which is a demagnetization direction of the permanent magnet, and the movable magnetic pole and the fixed magnetic pole are brought into a released position. The magnetic pole position detection method detects the position of the movable magnetic pole in a self-holding solenoid, and includes an attraction-side basic driving step of energizing the solenoid coil in the forward direction for a predetermined first time period to bring the movable magnetic pole and the fixed magnetic pole into the attracted position, and an attraction-side basic driving step of energizing the solenoid coil in the reverse direction for a predetermined second time period. a release-side basic drive step of causing the movable magnetic pole and the fixed magnetic pole to assume the release position; an attraction-side short-time drive step of causing the solenoid coil to be energized in the forward direction for a predetermined third time period shorter than the first time period after the supply of current to the solenoid coil in the forward direction has been stopped for the first time period; a release-side short-time drive step of causing the solenoid coil to be energized in the reverse direction for a predetermined fourth time period shorter than the second time period after the supply of current to the solenoid coil in the reverse direction has been stopped for the second time period; and a magnetic pole position detection step of detecting the relative position of the movable magnetic pole and the fixed magnetic pole based on a back electromotive force generated when the supply of current to the solenoid coil is stopped by the attraction-side short-time drive step and the release-side short-time drive step. Equipped with.
[0014] A magnetic pole position detection program according to one aspect of the present invention is a self-holding solenoid in which a movable magnetic pole and a fixed magnetic pole are brought into an attracted position by energizing a solenoid coil in a forward direction, which is a magnetization direction of the permanent magnet, and then the attracted position is maintained by the permanent magnet, and the movable magnetic pole is released from the permanent magnet by energizing the solenoid coil in a reverse direction, which is a demagnetization direction of the permanent magnet, so that the movable magnetic pole and the fixed magnetic pole are brought into a released position. In order to detect the position of the movable magnetic pole, a computer is provided to control an attraction-side basic drive means that energizes the solenoid coil in the forward direction for a predetermined first time period to bring the movable magnetic pole and the fixed magnetic pole into the attracted position, and an attraction-side basic drive means that energizes the solenoid coil in the reverse direction for a predetermined second time period. and a release-side short-time drive means for applying current to the solenoid coil in the forward direction for a predetermined third time period that is shorter than the first time period after the current flow to the solenoid coil in the forward direction has stopped for the first time period; a release-side short-time drive means for applying current to the solenoid coil in the reverse direction for a predetermined fourth time period that is shorter than the second time period after the current flow to the solenoid coil in the reverse direction has stopped for the second time period; and a magnetic pole position detection means for detecting the relative position of the movable magnetic pole and the fixed magnetic pole based on the back electromotive force generated when the current flow to the solenoid coil is stopped by the release-side short-time drive means and the release-side short-time drive means. [Effects of the Invention]
[0015] According to the above-mentioned magnetic pole position detection system, magnetic pole position detection method, and magnetic pole position detection program, the position of the magnetic pole can be detected accurately using the back electromotive force generated in the solenoid coil, while the self-holding solenoid can be operated stably. [Brief explanation of the drawings]
[0016] [Figure 1] 1A and 1B are diagrams illustrating the overall configuration of a magnetic pole position detection system according to a first embodiment of the present invention, in which FIG. 1A shows a state in which a magnetic pole is in an attracted position, and FIG. 1B shows a state in which a magnetic pole is in a released position. [Figure 2] 1A and 1B are simplified circuit diagrams showing the drive circuit in the magnetic pole position detection system, where FIG. 1A shows the case where a current is applied to the solenoid coil in the forward direction, and FIG. 1B shows the case where a current is applied to the solenoid coil in the reverse direction. [Figure 3] FIG. 2 is a functional block diagram of a drive control device in the magnetic pole position detection system. [Figure 4] 4 is a waveform diagram showing a time change in a drive current of a solenoid coil by a drive control device in the magnetic pole position detection system. FIG. [Figure 5] FIG. 2 is a functional block diagram of a position detection device in the magnetic pole position detection system. [Figure 6] 10A and 10B are waveform diagrams showing the time change in the potential at the terminal of the solenoid coil in the magnetic pole position detection system, where (a) shows the time when current is applied in the forward direction, and (b) shows the time when current is applied in the reverse direction. [Figure 7] 4 is a waveform diagram showing the time change in the voltage across the solenoid coil used when detecting a position in the position detection device in the magnetic pole position detection system. FIG. [Figure 8] FIG. 10 is a functional block diagram of a position detection device according to a modified example of the first embodiment. [Figure 9] 10A and 10B are waveform diagrams showing the time change in the potential at the terminal of the solenoid coil in the magnetic pole position detection system of the modified example, where FIG. 10A shows the time when current is applied in the forward direction, and FIG. [Figure 10] FIG. 10 is a functional block diagram of a position detection device in a magnetic pole position detection system according to a second embodiment of the present invention. [Figure 11] 10A and 10B are waveform diagrams showing the time change in the electric potential at the terminal of the solenoid coil used in the position detection device when detecting position in the magnetic pole position detection system of the second embodiment, where (a) shows the time when the solenoid coil is driven to the attraction side, and (b) shows the time when the solenoid coil is driven to the release side. DETAILED DESCRIPTION OF THE INVENTION
[0017] First Embodiment Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. (Overall composition) As shown in FIGS. 1(a) and 1(b), the magnetic pole position detection system 100 is a system that detects the position of a movable magnetic pole 203 (described later) in a self-holding solenoid 200. Here, the self-holding solenoid 200 of this embodiment is, for example, a direct-acting (push-pull) solenoid, and includes a solenoid coil 201, a fixed magnetic pole 202 on which the solenoid coil 201 is provided, a rod-shaped movable magnetic pole 203 that is provided so as to be movable relative to the fixed magnetic pole 202 in its longitudinal direction, a return spring 204 which is an elastic member that biases the movable magnetic pole 203 in a direction that moves it away from the fixed magnetic pole 202, and a permanent magnet 205 that holds the movable magnetic pole 203 on the side that attracts it to the fixed magnetic pole 202. Hereinafter, the posture in which the movable magnetic pole 203 is attracted to the fixed magnetic pole 202 will be referred to as the "attracted posture S1", and the posture in which the movable magnetic pole 203 is detached from the fixed magnetic pole 202 and the permanent magnet 205 will be referred to as the "detached posture S2".
[0018] In the self-holding solenoid 200, when current is passed through the solenoid coil 201 in the forward direction D1, the movable magnetic pole 203 and the fixed magnetic pole 202 assume an attracted position S1, and the attracted position S1 is then held by the permanent magnet 205 (see Figure 1(a)). When current is passed through the solenoid coil 201 in the reverse direction D2, the movable magnetic pole 203 disengages from the permanent magnet 205, and the movable magnetic pole 203 and the fixed magnetic pole 202 assume a disengaged position S2 (see Figure 1(b)).
[0019] Specifically, the magnetic pole position detection system 100 includes a drive circuit 1 that supplies a drive current to the solenoid coil 201 to drive the solenoid coil 201, a drive control device 2 that controls the drive circuit 1, and a position detection device 3 that detects the relative position of the movable magnetic pole 203 with respect to the fixed magnetic pole 202.
[0020] (Drive circuit) 2(a) and 2(b), the drive circuit 1 is configured as an H-bridge circuit including four switching elements 1a, 1b, 1c, and 1d, such as field-effect transistors. The drive circuit 1 is connected to the solenoid coil 201 so that the solenoid coil 201 can be energized in the forward direction D1 and the reverse direction D2 by the operation of the switching elements 1a, 1b, 1c, and 1d.
[0021] (Drive control device) The drive control device 2 is configured by, for example, a microcomputer including a microprocessor, and together with the position detection device 3 described later, stores various programs for executing a magnetic pole position detection method for detecting the position of the movable magnetic pole 203 relative to the fixed magnetic pole 202. Specifically, the drive control device 2 has an attraction-side basic drive unit 20, a detachment-side basic drive unit 21, an attraction-side short-time drive unit 22, and a detachment-side short-time drive unit 23, as shown in FIG.
[0022] The attraction-side basic drive unit 20 drives the switching elements 1a to 1d of the drive circuit 1, and energizes the solenoid coil 201 in the forward direction D1 for a predetermined first time t1, thereby placing the movable magnetic pole 203 and the fixed magnetic pole 202 in an attracted posture S1 (see FIGS. 1(a) and 4). When electricity is applied to the solenoid coil 201 in the forward direction D1, a magnetic field is generated in a direction that strengthens the magnetic field of the permanent magnet 205 of the self-holding solenoid 200 (magnetization direction), and the movable magnetic pole 203 is attracted to the fixed magnetic pole 202 by the attractive force generated by the solenoid coil 201 during the energization, thereby placing the movable magnetic pole 203 in the attracted posture S1, and even after the energization is stopped, the attractive force of the permanent magnet 205 is greater than the biasing force of the return spring 204 at the attracted posture S1, so the release posture S1 is maintained.
[0023] The detachment-side basic drive unit 21 drives the switching elements 1a to 1d of the drive circuit 1, and energizes the solenoid coil 201 in the reverse direction D2 for a predetermined second time t2, thereby placing the movable magnetic pole 203 and the fixed magnetic pole 202 in the detachment posture S2 (see FIGS. 1(b) and 4). When the solenoid coil 201 is energized in the reverse direction D2, a magnetic field is generated in a direction that weakens the magnetic field of the permanent magnet 205 of the self-holding solenoid 200 (demagnetization direction). The magnetic force of the permanent magnet 205 weakens during energization, and the movable magnetic pole 203 is pulled away from the fixed magnetic pole 202 by the biasing force of the return spring 204 of the self-holding solenoid 200, resulting in the detachment posture S2. Even after the energization is stopped, the detachment posture S2 is maintained because the biasing force of the return spring 204 is greater than the attractive force of the permanent magnet 205.
[0024] After stopping the supply of current to the solenoid coil 201 in the forward direction D1 for a first time t1, the attraction-side short-time drive unit 22 drives the switching elements 1a-1d of the drive circuit 1 to supply current to the solenoid coil 201 in the forward direction D1 for a predetermined third time t3 that is shorter than the first time t1 (see FIG. 4). The attraction-side short-time drive unit 22 may execute the short-time supply of current in the forward direction D1 only once, or may repeat the same multiple times.
[0025] After stopping the supply of current to the solenoid coil 201 in the reverse direction D2 for the second time t2, the detachment-side short-time drive unit 23 drives the switching elements 1a-1d of the drive circuit 1 to supply current to the solenoid coil 201 in the reverse direction D2 for a predetermined fourth time t4 that is shorter than the second time t2 (see FIG. 4). The detachment-side short-time drive unit 23 may execute the short-time supply of current in the reverse direction D2 only once, or may repeat this process multiple times.
[0026] (position detection device) As shown in FIG. 5, the position detection device 3 is configured by a microcomputer including a microprocessor and a circuit including a comparator, and stores various programs for carrying out the magnetic pole position detection method together with the drive control device 2. Specifically, the position detection device 3 detects the relative position between the fixed magnetic pole 202 and the movable magnetic pole 203 based on the back electromotive force generated when the attraction-side short-time drive unit 22 and the release-side short-time drive unit 23 stop energizing the solenoid coil 201. That is, the position detection device 3 has a coil potential acquisition unit 30, a coil voltage calculation unit 31, and a position calculation unit 32.
[0027] The coil potential acquisition unit 30 acquires the potential VA of the first end 201a of the solenoid coil 201 and the potential VB of the second end 201b.
[0028] The coil voltage calculation unit 31 calculates the voltage V across the solenoid coil 201 from the difference between the potentials VA and VB across the two ends 201a and 201b of the solenoid coil 201. For example, when the solenoid coil 201 is energized in the forward direction D1 as shown in FIG. 6(a), a subtractor (not shown) subtracts the potential VB at the second end 201b from the potential VA at the first end 201a to generate a waveform (normal waveform) of the voltage V across the two ends. When the solenoid coil 201 is energized in the reverse direction D2 as shown in FIG. 6(b), a subtractor (not shown) subtracts the potential VB at the second end 201b from the potential VA to generate a normal waveform of the voltage V across the two ends, and then an inverter (not shown) generates an inverted waveform.
[0029] The position calculation unit 32 calculates the relative position of the fixed magnetic pole 202 and the movable magnetic pole 203 from the voltage V between both ends of the solenoid coil 201. That is, the position calculation unit 32 calculates the relative position of the fixed magnetic pole 202 and the movable magnetic pole 203 from the time tx from when the attraction-side short-time drive unit 22 and the release-side short-time drive unit 23 stop energizing the solenoid coil 201 until a predetermined reference voltage Vs is reached, as shown in Fig. 7. This time tx can be obtained by converting an analog signal of the back electromotive force into a pulse signal by a comparator (not shown) and calculating the pulse width of the pulse signal.
[0030] When the fixed magnetic pole 202 and the movable magnetic pole 203 are in the attracted posture S1, the self-inductance of the solenoid coil 201 increases, causing the voltage V across the solenoid coil 201 based on the back electromotive force to converge slowly (see the dashed line in FIG. 7). On the other hand, when the fixed magnetic pole 202 and the movable magnetic pole 203 are in the disengaged posture S2, the self-inductance of the solenoid coil 201 decreases, causing the voltage V across the solenoid coil 201 based on the back electromotive force to converge quickly (see the solid line in FIG. 7). Therefore, the position calculation unit 32 determines that the fixed magnetic pole 202 and the movable magnetic pole 203 are in the attracted posture S1 when the time tx is longer than a predetermined reference time ts, and determines that the fixed magnetic pole 202 and the movable magnetic pole 203 are in the disengaged posture S2 when the time tx is shorter than the reference time ts. The reference time ts is a value that depends on the characteristics of the solenoid coil 201 and is set to, for example, a value between the pulse width in the attracted posture S1 and the pulse width in the disengaged posture S2.
[0031] (Action and effect) According to the magnetic pole position detection system 100 of the present embodiment described above, the solenoid coil 201 is driven for a short time when detecting the relative position of the movable magnetic pole 203 with respect to the fixed magnetic pole 202. This can disturb the attraction and release operations of the self-holding solenoid 200. However, in this embodiment, this short-time drive is performed to magnetize the permanent magnet 205 in the attracted position S1 and to demagnetize the permanent magnet 205 in the release position S2. Therefore, a position detection disturbance is input to increase the attraction force in the attracted position S1 and to promote release in the release position S2. Therefore, the back electromotive force generated in the solenoid coil 201 can be used to accurately detect the relative position of the fixed magnetic pole 202 and the movable magnetic pole 203, while stably operating the self-holding solenoid 200. Moreover, the short-time drive during position detection saves power.
[0032] Furthermore, the position detection device 3 detects the relative position between the fixed magnetic pole 202 and the movable magnetic pole 203 from the voltage V across the solenoid coil 201 when a back electromotive force is generated. Therefore, whether current is passed through the solenoid coil 201 in the forward direction D1 or the reverse direction D2, the convergence of the voltage V across the solenoid coil based on the back electromotive force can be accurately grasped, thereby improving the accuracy of position detection.
[0033] [Modification of the first embodiment] 8, the position detection device 3 may have a coil potential addition calculation unit 31X instead of the coil voltage calculation unit 31. As shown in FIGS. 9(a) and 9(b), the coil potential addition calculation unit 31X calculates a sum VX of the potentials at both ends of the solenoid coil 201 from the sum of the potential VA at the first end 201a of the solenoid coil 201 and the potential VB at the second end 201b.
[0034] In this case, when energizing the solenoid coil 201 in the reverse direction D2 as described above, there is no need to generate an inverted waveform using an inverter. In other words, the same waveform of the sum VX of the potentials at both ends can be obtained without using an inverter in both the forward direction D1 and the reverse direction D2, thereby simplifying the calculation.
[0035] Second Embodiment Next, a second embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In this embodiment, the configuration of the position detection device 3A is different from that in the first embodiment.
[0036] (position detection device) 10, the position detection device 3A has a coil potential acquisition unit 30 and a position calculation unit 32A. When the solenoid coil 201 is energized by the attraction-side short-time drive unit 22 of the drive control device 2, the position calculation unit 32A selects the potential of the first end 201a (see FIG. 1(a)), which is the upstream end in the forward direction D1, as the potential for calculating the relative position of the fixed magnetic pole 202 and the movable magnetic pole 203. When the solenoid coil 201 is energized by the release-side short-time drive unit 23, the position calculation unit 32A selects the potential of the second end 201b (see FIG. 1(b)), which is the upstream end in the reverse direction D2, as the potential for calculation. In this way, when the solenoid coil 201 is energized by the attraction-side short-time drive unit 22, the potential at the first end 201a is adopted, and when the solenoid coil 201 is energized by the release-side short-time drive unit 23, the potential at the second end 201b is adopted. Here, "adopting a potential" means switching to one of the potential measurements with a mechanical switch, or selecting one of the potentials on software.
[0037] 11(a) and 11(b), the position calculation unit 32A calculates the relative position of the fixed magnetic pole 202 and the movable magnetic pole 203 from the time tx1 from when the solenoid coil 201 is deenergized by the attraction-side short-time drive unit 22 and the release-side short-time drive unit 23 until the solenoid coil 201 reaches a predetermined reference potential V1s. As in the first embodiment, this time tx1 is obtained by calculating the pulse width of a pulse signal obtained by binarizing an analog signal representing the potential at the terminal of the solenoid coil 201 based on the back electromotive force using a comparator (not shown). The position calculation unit 32A determines that the fixed magnetic pole 202 and the movable magnetic pole 203 are in the attracted posture S1 if the time tx1 is longer than a predetermined reference time ts1, and determines that the fixed magnetic pole 202 and the movable magnetic pole 203 are in the released posture S2 if the time tx1 is shorter than the reference time ts1. The reference time ts1 is a value that depends on the characteristics of the solenoid coil 201, and is set to, for example, a value between the pulse width in the attracting posture S1 and the pulse width in the releasing posture S2. The reference potential V1s may be set to different values during attraction driving and release driving.
[0038] (Action and effect) According to the magnetic pole position detection system 100 of this embodiment described above, the position calculation unit 32A selectively uses the potential of the first end 201a, which is the upstream end in the forward direction D1, during short-time driving on the attraction side (current flow in the forward direction D1), and the potential of the second end 201b, which is the upstream end in the reverse direction D2, during short-time driving on the release side (current flow in the reverse direction D2), to detect the relative position of the fixed magnetic pole 202 and the movable magnetic pole 203.Therefore, regardless of whether current is flowing through the solenoid coil 201 in the forward direction D1 or the reverse direction D2, the convergence of the terminal potential of the solenoid coil based on the back electromotive force can be accurately grasped, and the accuracy of position detection can be improved.
[0039] The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention. For example, when the position calculation units 32, 32A calculate the relative position of the fixed magnetic pole 202 and the movable magnetic pole 203 and determine that the movable magnetic pole 203 is placed in an unintended position, that is, when the release position S2 is detected when the movable magnetic pole 203 should be in the attracted position, or when the release position S1 is detected when the movable magnetic pole 203 should be in the attracted position, the drive control device 2 may drive the drive circuit 1 to correct the attitude of the movable magnetic pole 203. Furthermore, when it is determined that the movable magnetic pole 203 is placed in an unintended position, the user may be notified by an alarm, a lamp, or the like. [Industrial Applicability]
[0040] According to the magnetic pole position detection system of the present invention, it is possible to operate a self-holding solenoid stably while accurately detecting the position of the magnetic pole using the back electromotive force generated in the solenoid coil. [Explanation of symbols]
[0041] 1...Drive circuit 2...Drive control device 3, 3A... Position detection device 20... Basic drive unit on the suction side 21...Detachable side basic drive unit 22...Suction side short-time drive unit 23...Removal side short-time drive unit 30... Coil potential acquisition unit 31... Coil voltage calculation unit 31X: Coil potential addition calculation section 32, 32A...Position calculation section 100...Magnetic pole position detection system 200...Self-holding solenoid 201...Solenoid coil 201a…first end 201b…Second end 202…Fixed magnetic pole 203...Movable magnetic pole 205...Permanent magnet D1…forward direction D2…Reverse direction S1...Suction posture S2: Withdrawal posture
Claims
1. A magnetic pole position detection system for detecting the position of a movable magnetic pole in a self-holding solenoid in which a movable magnetic pole and a fixed magnetic pole are brought into an attracted position by energizing a solenoid coil in a forward direction, which is a magnetization direction of the permanent magnet, and then the attracted position is maintained by the permanent magnet, and when energizing the solenoid coil in a reverse direction, which is a demagnetization direction of the permanent magnet, the movable magnetic pole is released from the permanent magnet, and the movable magnetic pole and the fixed magnetic pole are brought into a released position, comprising: a drive circuit that supplies a drive current to the solenoid coil to drive the solenoid coil so that the movable magnetic pole and the fixed magnetic pole are in the attracted position and the released position; a drive control device that controls the drive circuit; a position detection device for detecting the position of the movable magnetic pole; Equipped with The drive control device includes: an attraction-side basic drive unit that energizes the solenoid coil in the forward direction for a predetermined first time period to place the movable magnetic pole and the fixed magnetic pole in the attraction posture; a detachment-side basic drive unit that energizes the solenoid coil in the reverse direction for a predetermined second period of time to set the movable magnetic pole and the fixed magnetic pole in the detachment posture; an attraction-side short-time drive unit that, after the supply of current to the solenoid coil in the forward direction for the first period of time has been stopped, supplies current to the solenoid coil in the forward direction for a predetermined third period of time that is shorter than the first period of time; a detachment-side short-time drive unit that energizes the solenoid coil in the reverse direction for a predetermined fourth time period that is shorter than the second time period after the energization in the reverse direction to the solenoid coil has stopped for the second time period; and The position detection device is a magnetic pole position detection system that detects the relative position of the movable magnetic pole and the fixed magnetic pole based on the back electromotive force generated when the solenoid coil is de-energized by the attraction-side short-time drive unit and the release-side short-time drive unit.
2. The position detection device a coil potential acquisition unit that acquires potentials at both ends of the solenoid coil; a coil voltage calculation unit that calculates a voltage between both ends of the solenoid coil from a difference in potential between both ends of the solenoid coil; a position calculation unit that calculates a relative position between the movable magnetic pole and the fixed magnetic pole from the voltage across the solenoid coil; 2. The magnetic pole position detection system according to claim 1, comprising:
3. The position detection device a coil potential acquisition unit that acquires potentials at both ends of the solenoid coil; a coil potential addition calculation unit that calculates a sum of potentials at both ends of the solenoid coil from the sum of potentials at both ends of the solenoid coil; a position calculation unit that calculates a relative position between the movable magnetic pole and the fixed magnetic pole from the sum of the potentials at both ends of the solenoid coil; 2. The magnetic pole position detection system according to claim 1, comprising:
4. The position detection device a coil potential acquisition unit that acquires potentials at both ends of the solenoid coil; a position calculation unit that calculates a relative position between the movable magnetic pole and the fixed magnetic pole from the potentials at both ends; and The position calculation unit The potential for calculating the relative position is:
2. The magnetic pole position detection system according to claim 1, wherein when the attraction-side short-time drive unit energizes the solenoid coil, the potential at the upstream end in the forward direction is selected as the potential for calculation, and when the release-side short-time drive unit energizes the solenoid coil, the potential at the upstream end in the reverse direction is selected as the potential for calculation.
5. A magnetic pole position detection method for detecting the position of a movable magnetic pole in a self-holding solenoid, in which a movable magnetic pole and a fixed magnetic pole are brought into an attracted position by energizing a solenoid coil in a forward direction, which is a magnetization direction of the permanent magnet, and then the attracted position is maintained by the permanent magnet, and the movable magnetic pole is released from the permanent magnet by energizing the solenoid coil in a reverse direction, which is a demagnetization direction of the permanent magnet, and the movable magnetic pole and the fixed magnetic pole are brought into a released position, comprising: an attraction-side basic driving step of energizing the solenoid coil in the forward direction for a predetermined first time period to place the movable magnetic pole and the fixed magnetic pole in the attraction posture; a detachment-side basic driving step of energizing the solenoid coil in the reverse direction for a predetermined second time period to place the movable magnetic pole and the fixed magnetic pole in the detachment position; an attraction-side short-time driving step of energizing the solenoid coil in the forward direction for a predetermined third time period that is shorter than the first time period after the energization of the solenoid coil in the forward direction has stopped for the first time period; a detachment-side short-time driving step of energizing the solenoid coil in the reverse direction for a predetermined fourth time period that is shorter than the second time period after the energization in the reverse direction to the solenoid coil has been stopped for the second time period; a magnetic pole position detection step of detecting a relative position between the movable magnetic pole and the fixed magnetic pole based on a back electromotive force generated when the solenoid coil is de-energized by the attraction-side short-time driving step and the detachment-side long-time driving step; A magnetic pole position detection method comprising:
6. In a self-holding solenoid, in which a movable magnetic pole and a fixed magnetic pole are brought into an attracted position by energizing a solenoid coil in a forward direction, which is a magnetization direction of the permanent magnet, and then the attracted position is maintained by the permanent magnet, and in which the movable magnetic pole is released from the permanent magnet by energizing the solenoid coil in a reverse direction, which is a demagnetization direction of the permanent magnet, and the movable magnetic pole and the fixed magnetic pole are brought into a released position, a computer is configured to detect the position of the movable magnetic pole. an attraction-side basic driving means for energizing the solenoid coil in the forward direction for a predetermined first period of time to place the movable magnetic pole and the fixed magnetic pole in the attraction posture; a detachment-side basic driving means for energizing the solenoid coil in the reverse direction for a predetermined second period of time to bring the movable magnetic pole and the fixed magnetic pole into the detachment position; an attraction-side short-time drive means for energizing the solenoid coil in the forward direction for a predetermined third time period shorter than the first time period after the energization of the solenoid coil in the forward direction for the first time period has stopped; a detachment-side short-time driving means for energizing the solenoid coil in the reverse direction for a predetermined fourth time period shorter than the second time period after the energization in the reverse direction to the solenoid coil has been stopped for the second time period; and a magnetic pole position detecting means for detecting the relative position of the movable magnetic pole and the fixed magnetic pole based on the back electromotive force generated when the solenoid coil is de-energized by the attracting-side short-time driving means and the separating-side short-time driving means; A magnetic pole position detection program to function as a
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Patent Citations
Checking method for position of movable iron core for solenoid
JP1992196203A