Photoelectric feedback low-power-consumption double-coil electromagnet and switching method

Abstract

The invention particularly relates to a photoelectric feedback low-power-consumption double-coil electromagnet and a switching method, and solves the technical problems that when a mechanical microswitch is adopted by an existing electromagnet for position feedback, the magnitude of pressure borne by a button of the microswitch cannot be guaranteed, and the electromagnet is prone to being burnt or cannot be unlocked. The photoelectric feedback low-power-consumption double-coil electromagnet comprises a machine shell, a coil framework coaxially arranged in the machine shell, an unlocking coil, a holding coil, an armature, a magnet yoke, a photoelectric switch and a control circuit. The output of the in-place signal and the switching of the unlocking holding coil are realized, the power consumption is reduced, the unlocking suction force is improved, and the unlocking time is shortened. According to the switching method, the reliability of the electromagnet is obviously improved through the control circuit.

Description

Technical Field

[0001] The invention specifically relates to a low-power consumption double-coil electromagnet with photoelectric feedback and a switching method. Background Art

[0002] The electromagnet is a pin-type braking device that disengages (releases) when energized and brakes when the power is off with a spring. It has the advantages of compact structure, easy installation, wide adaptability, low noise, sensitive action, and reliable braking. As a power-off braking and locking device, it is widely used in electromechanical equipment in the fields of aviation, aerospace, etc.

[0003] Existing electromagnets use mechanical micro switches for position feedback. The internal reed of the micro switch is stressed to switch the micro switch contacts and feedback the position signal. When the electromagnet is energized, the coil generates electromagnetic attraction, and the armature moves under the action of the electromagnetic attraction, driving the push rod on it to contact the button of the micro switch. When the micro switch button is pressed, the internal reed changes to switch the micro switch contacts.

[0004] Since the pressure on the micro switch button cannot be guaranteed, it often affects the normal switching of the micro switch. When the pressure is small, the internal reed cannot switch, and the electromagnet unlocking coil is passed through a large current for a long time, which will cause the electromagnet to burn out; when the pressure is large, the button and the internal reed are deformed, making it impossible to reset the button, and the electromagnet cannot be unlocked when the power is turned on again. Summary of the invention

[0005] The purpose of the present invention is to solve the technical problem that when the existing electromagnet uses a mechanical micro switch for position feedback, the pressure strength of the micro switch button cannot be guaranteed, which easily leads to the electromagnet burning or failure to unlock, and provide a low-power double-coil electromagnet with photoelectric feedback and a switching method.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A low-power double-coil electromagnet with photoelectric feedback, which is special in that it includes a housing, a coil frame coaxially arranged in the housing, an unlocking coil, a holding coil, an armature, a yoke, a photoelectric switch and a control circuit;

[0008] The armature and the yoke are coaxially arranged outside the coil frame from front to back;

[0009] The holding coil and the unlocking coil are evenly wound on the coil frame from the inside to the outside, and the unlocking coil and the holding coil are electrically connected to the control circuit respectively, so as to generate an excitation current to make the armature move axially;

[0010] The front end of the armature extends out of the housing, and the rear end passes through the front end of the housing and extends into the interior of the coil frame, and the armature can move axially relative to the housing, and a push rod is coaxially arranged at the rear end of the armature;

[0011] The photoelectric switch is coaxially arranged inside the magnetic yoke, and the receiving end of the photoelectric switch cooperates with the push rod, and the transmitting end is electrically connected to the control circuit, so as to control the conduction and disconnection of the unlocking coil;

[0012] A working spring is arranged between the front end of the yoke and the rear end of the armature, and the working spring is used to drive the armature and the push rod to reset when the unlocking coil is powered off.

[0013] Furthermore, a step hole is provided inside the magnetic yoke, the large end of the step hole is located at the rear end of the magnetic yoke, and the receiving end of the photoelectric switch is provided inside the large end of the step hole;

[0014] The rear end of the push rod is located in the small end of the step hole, and the push rod matches with the receiving end of the photoelectric switch along the axial direction of the step hole.

[0015] Furthermore, the front end of the yoke is provided with a groove opening toward the rear end of the armature;

[0016] The working spring is coaxially sleeved on the outer side of the push rod, one end of the working spring is connected to the inner bottom of the groove, and the other end is connected to the rear end of the armature.

[0017] Furthermore, the housing comprises a front cover, a middle cover and a rear cover which are sequentially connected from front to back;

[0018] A cylindrical housing is coaxially arranged inside the front cover, the front end of the armature is arranged in the cylindrical housing through a sliding bearing, and a limiting hole is arranged on the cylindrical housing to limit the axial movement of the sliding bearing;

[0019] It also includes a printed circuit board; the control circuit is arranged on the printed circuit board, and the printed circuit board is located between the middle cover and the rear cover.

[0020] Further, the photoelectric switch includes a resistor R1, a resistor R2, a resistor R3, a diode and a forward transistor;

[0021] The anode of the diode is connected to the positive electrode of the external power supply through the resistor R1, the cathode is connected to the negative electrode of the external power supply through the resistor R2, and the negative electrode of the external power supply is grounded;

[0022] The base of the forward transistor is used to receive an external optical signal, the collector is connected to the positive electrode of the external power supply through the resistor R3, and the emitter is grounded.

[0023] Furthermore, the control circuit includes a resistor R4, a resistor R5, a reverse transistor and a MOS tube;

[0024] The base of the reverse transistor is connected to the collector of the forward transistor, the collector is connected to the positive electrode of the external power supply through the resistor R4, and the emitter is grounded;

[0025] The G pole of the MOS tube is connected to the collector of the reverse transistor through the resistor R5, the D pole is connected to one end of the unlocking coil, and the S pole is grounded; the other end of the unlocking coil is connected to the positive pole of the external driving voltage;

[0026] One end of the holding coil is connected to the positive electrode of the external driving voltage, and the other end is connected to the negative electrode of the external driving voltage, and the negative electrode of the external driving voltage is grounded.

[0027] Furthermore, the cylindrical shell, the armature, and the yoke are all made of magnetic conductive materials;

[0028] The push rod, coil frame and rear cover are all made of aluminum alloy or stainless steel;

[0029] The groove is an annular groove;

[0030] The working spring is a helical compression spring.

[0031] At the same time, the present invention also provides a low-power dual-coil switching method with photoelectric feedback, which is based on the above-mentioned low-power dual-coil electromagnet with photoelectric feedback, and its special feature is that it includes the following steps:

[0032] When the armature is not attracted in place, the photoelectric switch is in the on state and outputs a low level; the low level is inverted by the control circuit and used as a control signal to control the MOS tube to turn on, so that the unlocking coil and the holding coil work at the same time to generate electromagnetic force to make the armature move axially;

[0033] When the armature is attracted in place, the photoelectric switch is in the cut-off state and outputs a high level; the high level is inverted by the control circuit and used as a control signal to control the MOS tube to turn off, then the unlocking coil is powered off and stops working, the holding coil continues to work, and the working spring drives the armature and push rod to reset, realizing the dual coil switching and unlocking.

[0034] Furthermore, the low level is inverted by the control circuit and used as a control signal to control the conduction of the MOS tube as follows:

[0035] The low level is converted into a high level after passing through the reverse transistor, and the high level is used as a control signal to control the MOS tube to be turned on.

[0036] Furthermore, the high level is inverted by the control circuit and used as a control signal to control the MOS tube to turn off as follows:

[0037] The high level is converted into a low level after passing through the reverse transistor, and the low level is used as a control signal to control the MOS tube to turn off.

[0038] Beneficial effects of the present invention:

[0039] 1. The present invention is a low-power double-coil electromagnet with photoelectric feedback. A hardware control circuit is integrated on the electromagnet. The feedback signal of the photoelectric switch controls the on-off of the MOS tube to achieve the output of the in-position signal (i.e., low level) and the switching of the unlocking coil and the holding coil, thereby reducing power consumption, improving the unlocking suction force, and shortening the unlocking time.

[0040] 2. The present invention provides a low-power consumption double-coil electromagnet with photoelectric feedback, which ensures the axial movement of the armature through a sliding bearing, thereby reducing the resistance to the movement of the armature.

[0041] 3. The low-power consumption double-coil electromagnet with photoelectric feedback of the present invention improves the reliability of the electromagnet by adding an in-position feedback structure (push rod and photoelectric switch) and using the photoelectric switch to feedback the in-position signal. The result is simple and the operability is strong.

[0042] 4. The present invention provides a low-power dual-coil switching method with photoelectric feedback. The control circuit is used to significantly improve the reliability of the electromagnet and significantly increase its working life. Moreover, the principle is simple and can be applied to conventional electromagnets. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a structural schematic diagram of an embodiment of a low-power-consumption double-coil electromagnet with photoelectric feedback of the present invention;

[0044] Figure 2 It is a schematic diagram of magnetic circuit flow in an embodiment of a low-power consumption double-coil electromagnet with photoelectric feedback of the present invention;

[0045] Figure 3 It is a schematic diagram of a control circuit in an embodiment of a low-power consumption double-coil electromagnet with photoelectric feedback of the present invention;

[0046] Figure 4 Schematic diagram of the initial attraction stage of a low-power consumption double-coil electromagnet with photoelectric feedback according to the present invention, wherein the horizontal axis represents time and the vertical axis represents electromagnetic attraction force;

[0047] Figure 5 It is a schematic diagram of the unlocking stage in an embodiment of a low-power double-coil electromagnet with photoelectric feedback of the present invention, wherein the horizontal axis represents time and the vertical axis represents electromagnetic suction force.

[0048] Description of reference numerals:

[0049] 1- housing, 101- front cover, 102- middle cover, 103- rear cover, 104- cylindrical housing, 2- coil frame, 3- unlocking coil, 4- holding coil, 5- armature, 6- yoke, 61- step hole, 62- groove, 7- photoelectric switch, 8- sliding bearing, 9- control circuit, 10- printed circuit board, 11- push rod, 12- working spring. DETAILED DESCRIPTION

[0050] like Figure 1 and Figure 2 As shown, a low-power double-coil electromagnet with photoelectric feedback includes a housing 1, a coil frame 2 coaxially arranged in the housing 1, an unlocking coil 3, a holding coil 4, an armature 5, a yoke 6, a photoelectric switch 7, a sliding bearing 8, and a control circuit 9 arranged on a printed circuit board 10; the armature 5 and the yoke 6 are coaxially arranged in the coil frame 2 from front to back; the holding coil 4 and the unlocking coil 3 are uniformly wound on the coil frame 2 from inside to outside in sequence, and the unlocking coil 3 and the holding coil 4 are respectively electrically connected to the control circuit 9, which is used to generate an excitation current to make the armature 5 move axially. Movement; the front end of the armature 5 extends out of the casing 1, and the rear end passes through the front end of the casing 1 and extends into the interior of the coil frame 2, and the armature 5 can move axially relative to the casing 1, and the rear end of the armature 5 is coaxially provided with a push rod 11; the photoelectric switch 7 is coaxially arranged inside the yoke 6, and the receiving end of the photoelectric switch 7 cooperates with the push rod 11, and the transmitting end is electrically connected to the control circuit 9, which is used to control the conduction and shutdown of the unlocking coil 3; a working spring 12 is arranged between the front end of the yoke 6 and the rear end of the armature 5, and the working spring 12 is used to drive the armature 5 and the push rod 11 to reset when the unlocking coil 3 is powered off.

[0051] A stepped hole 61 is provided inside the yoke 6, the large end of the stepped hole 61 is located at the rear end of the yoke 6, and the receiving end of the photoelectric switch 7 is provided in the large end of the stepped hole 61; the rear end of the push rod 11 is located in the small end of the stepped hole 61, and the push rod 11 matches the receiving end of the photoelectric switch 7 along the axial direction of the stepped hole 61. A groove 62 with an opening toward the rear end of the armature 5 is provided at the front end of the yoke 6; the working spring 12 is coaxially sleeved on the outside of the push rod 11, one end of the working spring 12 is connected to the inner bottom of the groove 62, and the other end is connected to the rear end of the armature 5. The housing 1 includes a front cover 101, a middle cover 102 and a rear cover 103 which are connected in sequence from front to back; a cylindrical shell 104 is coaxially arranged inside the front cover 101, and the front end of the armature 5 is arranged in the cylindrical shell 104 through a sliding bearing 8. A limiting hole is arranged on the cylindrical shell 104 to limit the axial movement of the sliding bearing 8; the control circuit 9 and the printed circuit board 10 are located between the middle cover 102 and the rear cover 103, and the rear cover 103 forms a protection for the control circuit 9.

[0052] like Figure 3 As shown, the photoelectric switch 7 includes a resistor R1, a resistor R2, a resistor R3, a diode and a forward transistor; the anode of the diode is connected to the positive electrode of the external power supply through the resistor R1, and the cathode is connected to the negative electrode of the external power supply through the resistor R2; the base of the forward transistor is used to receive an external light signal, the collector is connected to the positive electrode of the external power supply through the resistor R3, the emitter is grounded, and the negative electrode of the external power supply is connected.

[0053] The control circuit 9 includes a resistor R4, a resistor R5, a reverse transistor and a MOS tube; the base of the reverse transistor is connected to the collector of the forward transistor, the collector is connected to the positive electrode of the external power supply through the resistor R4, and the emitter is grounded; the G pole of the MOS tube is connected to the collector of the reverse transistor through the resistor R5, the D pole is connected to one end of the unlocking coil 3, and the S pole is grounded; the other end of the unlocking coil 3 is connected to the positive electrode of the external driving voltage; one end of the holding coil 4 is connected to the positive electrode of the external driving voltage, and the other end is connected to the negative electrode of the external driving voltage, and the negative electrode of the external driving voltage is grounded.

[0054] When the electromagnet is not in place, the silicon phototransistor of the photoelectric switch 7 is in the on state, outputting a low level, and the low level signal is converted to a high level after being inverted by the reverse transistor, driving the MOS tube to conduct, and the unlocking coil 3 is energized. When the electromagnet is in place, the silicon phototransistor of the photoelectric switch 7 is in the off state, outputting a high level, and the high level signal is converted to a low level after being inverted by the reverse transistor, the MOS tube is turned off, and the unlocking coil 3 is de-energized.

[0055] In this embodiment, the cylindrical housing 104, the armature 5, and the yoke 6 are all made of magnetic conductive materials; the push rod 11, the coil frame 2, and the back cover 103 are all made of aluminum alloy or stainless steel. The photoelectric switch 7, the forward triode, the reverse triode, the MOS tube, and all the resistors are welded on the printed circuit board 10. The unlocking coil 3 and the holding coil 4 are evenly wound in the winding area of ​​the coil frame 2. The groove 62 is an annular groove; the working spring 12 is a helical compression spring.

[0056] In order to improve the reliability of the electromagnet, it is necessary to transform the contact feedback of the traditional electromagnet micro switch into contactless feedback. With the help of the photoelectric signal of the photoelectric switch 7, the position feedback of the electromagnet is obtained. On this basis, the corresponding control circuit 9 is further designed. Through the control circuit 9, the in-position signal can be output, and the switching of the unlocking and holding coil 4 can be quickly realized, reducing the power consumption of the electromagnet.

[0057] Reasonable setting of the installation position of the push rod 11, that is, adjusting the position of the push rod 11 entering the step hole 61 of the photoelectric switch 7, can ensure the effective switching of the photoelectric switch 7. By optimizing the parameters of the unlocking coil 3, the electromagnetic attraction during unlocking can be improved, and the armature 5 can be kept quickly attracted. By optimizing the parameters of the holding coil 4, the power consumption of the armature 5 during operation can be reduced. By reasonably selecting components such as triodes and MOS tubes, the control circuit 9 can operate normally, and the reliability of the electromagnet is improved. In order to further optimize the electromagnetic attraction of the electromagnet, the finite element simulation method can also be used to obtain the structural parameters of the armature 5 and the yoke 6.

[0058] At the same time, the present invention is based on a low-power double-coil electromagnet with photoelectric feedback, and proposes a low-power double-coil switching method with photoelectric feedback, comprising the following steps:

[0059] like Figure 4 As shown in the figure, when the power is just turned on, the armature 5 is not attracted in place, the photoelectric switch 7 is in the on state, and the output is low level; the low level is inverted by the control circuit 9 and used as a control signal to control the MOS tube to turn on, so the unlocking coil 3 and the holding coil 4 work at the same time to generate electromagnetic force to make the armature 5 move axially; Figure 4 It can be seen that in the initial state, when the electromagnetic attraction force changes with time and gradually increases, the air gap of the electromagnet is the longest at this time, and under the action of the driving voltage, the electromagnetic attraction force is much greater than the external force exerted on the armature 5 at this time, so the electromagnet can be normally attracted.

[0060] like Figure 5 As shown, when the push rod 11 at the rear end of the armature 5 enters the photoelectric switch 7, the armature 5 is attracted in place, the photoelectric switch 7 is in the cut-off state, and outputs a high level; the high level is inverted by the control circuit 9 and used as a control signal to control the MOS tube to turn off, then the unlocking coil 3 is powered off and stops working, the holding coil 4 continues to work, and the working spring 12 drives the armature 5 and the push rod 11 to reset, realizing the double coil switching and unlocking. Figure 5 It can be seen that during the attraction process, the push rod 11 enters the photoelectric switch 7, and the photoelectric switch 7 outputs a position signal, only keeping the coil 4 working; at this time, the internal current of the keeping coil 4 is significantly reduced, and the electromagnetic force it is subjected to is still much greater than the external force exerted on the armature 5 at this time. Therefore, when the keeping coil 4 is working, the current is significantly reduced, and then the power consumption is significantly reduced, and the electromagnet can still reliably maintain the attraction state, thereby achieving the purpose of reducing power consumption.

[0061] The low level is inverted by the control circuit 9 and used as a control signal to control the MOS tube to be turned on. Specifically, the low level is converted to a high level after passing through the reverse transistor, and the high level is used as a control signal to control the MOS tube to be turned on. The high level is inverted by the control circuit 9 and used as a control signal to control the MOS tube to be turned off. Specifically, the high level is converted to a low level after passing through the reverse transistor, and the low level is used as a control signal to control the MOS tube to be turned off.

[0062] By energizing the unlocking coil 3 and the holding coil 4 for excitation, under the action of the excitation current, the armature 5 moves axially under the action of the electromagnetic force, and its push rod 11 enters the photoelectric switch 7. The photoelectric switch 7 outputs a position signal (i.e., a low level), and then controls the shutdown of the unlocking coil 3 through the MOS tube.

Claims

1. A low-power double-coil electromagnet with photoelectric feedback, characterized in that: It comprises a housing (1), a coil frame (2) coaxially arranged in the housing (1), an unlocking coil (3), a holding coil (4), an armature (5), a magnetic yoke (6), a photoelectric switch (7) and a control circuit (9); The armature (5) and the yoke (6) are coaxially arranged in the coil frame (2) from front to back; The holding coil (4) and the unlocking coil (3) are evenly wound on the coil frame (2) from the inside to the outside, and the unlocking coil (3) and the holding coil (4) are respectively electrically connected to the control circuit (9) for generating an excitation current to make the armature (5) move axially; The front end of the armature (5) extends out of the housing (1), and the rear end passes through the front end of the housing (1) and extends into the interior of the coil frame (2); the armature (5) is axially movable relative to the housing (1), and a push rod (11) is coaxially arranged at the rear end of the armature (5); The photoelectric switch (7) is coaxially arranged inside the magnetic yoke (6), and the receiving end of the photoelectric switch (7) cooperates with the push rod (11), and the transmitting end is electrically connected to the control circuit (9), so as to control the conduction and disconnection of the unlocking coil (3); A working spring (12) is arranged between the front end of the yoke (6) and the rear end of the armature (5), and the working spring (12) is used to drive the armature (5) and the push rod (11) to reset when the unlocking coil (3) is powered off.

2. The low-power consumption double-coil electromagnet with photoelectric feedback according to claim 1, characterized in that: A stepped hole (61) is provided inside the magnetic yoke (6), a large end of the stepped hole (61) is located at the rear end of the magnetic yoke (6), and the photoelectric switch (7) is arranged inside the large end of the stepped hole (61); The rear end of the push rod (11) is located in the small end of the step hole (61), and the push rod (11) matches with the receiving end of the photoelectric switch (7) along the axial direction of the step hole (61).

3. The low-power consumption double-coil electromagnet with photoelectric feedback according to claim 2, characterized in that: The front end of the yoke (6) is provided with a groove (62) opening toward the rear end of the armature (5); The working spring (12) is coaxially sleeved on the outside of the push rod (11), one end of the working spring (12) is connected to the inner bottom of the groove (62), and the other end is connected to the rear end of the armature (5).

4. The low-power consumption double-coil electromagnet with photoelectric feedback according to claim 3 is characterized in that: The housing (1) comprises a front cover (101), a middle cover (102) and a rear cover (103) which are connected in sequence from front to back; A cylindrical housing (104) is coaxially arranged inside the front cover (101), the front end of the armature (5) is arranged in the cylindrical housing (104) via a sliding bearing (8), and a limiting hole is arranged on the cylindrical housing (104) for limiting the axial movement of the sliding bearing (8); It also includes a printed circuit board (10); the control circuit (9) is arranged on the printed circuit board (10), and the printed circuit board (10) is located between the middle cover (102) and the rear cover (103).

5. A low-power consumption double-coil electromagnet with photoelectric feedback according to any one of claims 1 to 4, characterized in that: The photoelectric switch (7) comprises a resistor R1, a resistor R2, a resistor R3, a diode and a forward transistor; The anode of the diode is connected to the positive electrode of the external power supply through the resistor R1, the cathode is connected to the negative electrode of the external power supply through the resistor R2, and the negative electrode of the external power supply is grounded; The base of the forward transistor is used to receive an external optical signal, the collector is connected to the positive electrode of the external power supply through the resistor R3, and the emitter is grounded.

6. The low-power consumption double-coil electromagnet with photoelectric feedback according to claim 5, characterized in that: The control circuit (9) comprises a resistor R4, a resistor R5, a reverse transistor and a MOS tube; The base of the reverse transistor is connected to the collector of the forward transistor, the collector is connected to the positive electrode of the external power supply through the resistor R4, and the emitter is grounded; The G pole of the MOS tube is connected to the collector of the reverse transistor through a resistor R5, the D pole is connected to one end of the unlocking coil (3), and the S pole is grounded; the other end of the unlocking coil (3) is connected to the positive pole of the external driving voltage; One end of the holding coil (4) is connected to the positive electrode of the external driving voltage, and the other end is connected to the negative electrode of the external driving voltage, and the negative electrode of the external driving voltage is grounded.

7. The low-power consumption double-coil electromagnet with photoelectric feedback according to claim 4, characterized in that: The cylindrical shell (104), the armature (5) and the yoke (6) are all made of magnetic conductive materials; The push rod (11), coil frame (2) and rear cover (103) are all made of aluminum alloy or stainless steel; The groove (62) is an annular groove; The working spring (12) is a helical compression spring.

8. A low-power dual-coil switching method with photoelectric feedback, based on a low-power dual-coil electromagnet with photoelectric feedback as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: When the armature (5) is not attracted in place, the photoelectric switch (7) is in a conducting state and outputs a low level; the low level is inverted by the control circuit (9) and used as a control signal to control the MOS tube to conduct, so that the unlocking coil (3) and the holding coil (4) work simultaneously to generate electromagnetic force to make the armature (5) move axially; When the armature (5) is attracted in place, the photoelectric switch (7) is in a cut-off state and outputs a high level; the high level is inverted by the control circuit (9) and used as a control signal to control the MOS tube to turn off, so that the unlocking coil (3) is powered off and stops working, while the holding coil (4) continues to work, and the working spring (12) drives the armature (5) and the push rod (11) to reset, thereby realizing the switching of the double coils and unlocking.

9. A low-power dual-coil switching method with photoelectric feedback according to claim 8, characterized in that: The low level is inverted by the control circuit (9) and used as a control signal to control the conduction of the MOS tube. Specifically: The low level is converted into a high level after passing through the reverse transistor, and the high level is used as a control signal to control the MOS tube to be turned on.

10. A low-power dual-coil switching method with photoelectric feedback according to claim 9, characterized in that: The high level is inverted by the control circuit (9) and used as a control signal to control the MOS tube to turn off. Specifically: The high level is converted into a low level after passing through the reverse transistor, and the low level is used as a control signal to control the MOS tube to turn off.

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