Motor protection circuit and motor protection system

Abstract

The utility model discloses a motor protection circuit and a motor protection system. The motor protection circuit comprises a first switch circuit, a servo driver, an outer side forward limit switch, an outer side reverse limit switch, an emergency stop button and a safety relay. A first power supply end of the servo driver is connected with an external power supply through a first switching circuit, and an output end of the servo driver is connected with the motor; the outer side forward limit switch, the outer side reverse limit switch and the scram button are connected in series between the first input end and the second input end of the safety relay; the output end of the safety relay is connected with the first switching circuit; through linkage of the outer side forward limit switch, the outer side reverse limit switch and the scram button, when any one of the outer side forward limit switch, the outer side reverse limit switch and the scram button breaks down, other normal elements can be normally triggered, so that the servo driver drives the motor to stop moving in time, and the safety of the motor in the running process is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor technology field especially relates to a motor protection circuit and motor protection system. BACKGROUND

[0002] In modern industrial production, motor as an important power equipment is widely used in various mechanical equipment, and its running state directly affects production efficiency and product quality. However, the motor may cause failure due to various reasons during operation, such as overload, short circuit and overheating, and even cause accidents. Therefore, it is necessary to effectively protect the motor. Limit switch is a commonly used motor protection device, which can control the running state of the motor according to the actual position of the motor to prevent the motor from exceeding the allowed running range, so as to protect the motor, equipment and operator safety.

[0003] However, when the limit switch fails, the motor cannot stop running in time, which may cause accidents. Therefore, how to improve the safety of the motor during operation has become a technical problem to be solved at present. UTILITY MODEL CONTENTS

[0004] The utility model embodiment provides a kind of motor protection circuit and motor protection system to solve how to improve the safety problem of motor during operation.

[0005] A kind of motor protection circuit, including first switch circuit, servo driver, outer side positive limit switch, outer side reverse limit switch, emergency stop button and safety relay;

[0006] The first power supply end of the servo driver is connected with external power supply by the first switch circuit, and the output end of the servo driver is used to connect motor;

[0007] The outer side positive limit switch, the outer side reverse limit switch and the emergency stop button are connected in series between the first input end and the second input end of the safety relay;

[0008] The output end of the safety relay is connected with the first switch circuit;

[0009] When any one of the outer side positive limit switch, the outer side reverse limit switch and the emergency stop button is triggered, the safety relay controls the first switch circuit to be disconnected, so that the servo driver drives the motor to stop moving.

[0010] Further, the number of emergency stop buttons is two;

[0011] The first safety contact of the outer positive limit switch and the first safety contact of the outer negative limit switch are connected in series between the first input end and the second input end of the safety relay and the emergency stop button;

[0012] The second safety contact of the outer positive limit switch and the second safety contact of the outer negative limit switch are connected in series between the third input end and the fourth input end of the safety relay and the other emergency stop button.

[0013] Further, the first switch circuit comprises a contactor; the contactor comprises a main contact and a first coil;

[0014] The main contact is connected with the external power supply and a first power supply end of the servo driver;

[0015] The first coil is connected with a first power supply end and the safety relay, for controlling the main contact to work under the control of the safety relay.

[0016] Further, the motor protection circuit further comprises a switching power supply;

[0017] The input end of the switching power supply is used for connecting the external power supply, and the output end of the switching power supply is connected with the contactor, a second power supply end of the servo driver and a third power supply end of the safety relay.

[0018] Further, the motor protection circuit further comprises an inner limit switch; the inner limit switch is connected with the servo driver;

[0019] When the inner limit switch is triggered by the motor, the signal output by the inner limit switch controls the servo driver to drive the motor to stop moving.

[0020] Further, the inner limit switch comprises an inner positive limit switch and an inner negative limit switch;

[0021] The first safety contact and the second safety contact of the inner positive limit switch are connected in series between the output end of the switching power supply and a first control end of the servo driver;

[0022] The first safety contact and the second safety contact of the inner negative limit switch are connected in series between the output end of the switching power supply and a second control end of the servo driver.

[0023] Further, the motor protection circuit further comprises a reset switch;

[0024] The reset switch is connected in series between the fifth input end and the sixth input end of the safety relay and the contactor, for resetting the safety relay.

[0025] Further, the normally closed contact of the reset switch and the auxiliary normally closed contact of the contactor are connected in series between the fifth input end and the sixth input end of the safety relay;

[0026] The normally open contact of the reset switch and the auxiliary normally open contact of the contactor are connected in series on the second power supply end of the servo driver.

[0027] Further, a filter is further arranged between the first power supply end of the servo driver and the first switch circuit.

[0028] A motor protection system comprising a guide rail and the motor protection circuit described above; the outer positive limit switch and the outer negative limit switch are arranged on the guide rail respectively, and the motor is arranged between the outer positive limit switch and the outer negative limit switch;

[0029] When any one of the outer positive limit switch, the outer negative limit switch and the emergency stop button is triggered, the safety relay controls the first switch circuit to be disconnected, so that the servo driver drives the motor to stop moving.

[0030] The motor protection circuit and the motor protection system described above, the motor protection circuit comprises a first switch circuit, a servo driver, an outer positive limit switch, an outer negative limit switch, an emergency stop button and a safety relay; the first power supply end of the servo driver is connected to an external power supply through the first switch circuit, and the output end of the servo driver is used for connecting a motor; the outer positive limit switch, the outer negative limit switch and the emergency stop button are arranged in series between the first input end and the second input end of the safety relay; the output end of the safety relay is connected to the first switch circuit; when any one of the outer positive limit switch, the outer negative limit switch and the emergency stop button is triggered, the safety relay controls the first switch circuit to be disconnected, so that the servo driver drives the motor to stop moving; through the linkage of the outer positive limit switch, the outer negative limit switch and the emergency stop button, when any one of the outer positive limit switch, the outer negative limit switch and the emergency stop button is triggered, the safety relay can control the first switch circuit to be disconnected, so that the servo driver drives the motor to stop moving, and further, when any one of the outer positive limit switch, the outer negative limit switch and the emergency stop button fails, the other normal elements can be triggered normally, so that the servo driver drives the motor to stop moving in time, and the safety in the process of motor operation is improved. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0032] Figure 1 is a circuit schematic diagram of a motor protection circuit in an embodiment of the present application;

[0033] Figure 2 is another circuit schematic diagram of a motor protection circuit in an embodiment of the present application;

[0034] Figure 3 is another circuit schematic diagram of a motor protection circuit in an embodiment of the present application

[0035] Figure 4 is a schematic diagram of a motor protection system in an embodiment of the present application. DETAILED DESCRIPTION

[0036] The technical scheme in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0037] It should be understood that the present application can be implemented in different forms and should not be interpreted as being limited to the embodiments presented herein. On the contrary, these embodiments are provided to make the disclosure complete and complete, and to fully convey the scope of the present application to those skilled in the art. In the drawings, the size and relative size of the layers and regions may be exaggerated for clarity. The same reference numerals represent the same elements throughout the drawings.

[0038] It will be understood that when an element or layer is referred to as being "on" or "connected to" another element or layer, it can be directly on or connected to the other element or layer or intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application.

[0039] Spatially relative terms, such as "beneath", "below", "lower", "under", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and / or

[0040] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0041] For the purpose of promoting an understanding of the present application, the present application will now be described in detail with reference to the following description and the illustrative figures. The novel features of the present application are set forth with particularity in the appended claims. The present application, together with its advantages, can best be understood from the following description and the illustrative figures.

[0042] This embodiment provides a motor protection circuit for use in power equipment, which includes a motor-M1 and a motor protection system. Exemplarily, the motor-M1 is a linear motor-M1. The motor protection system includes a guide rail 10 and a motor protection circuit. The linear motor-M1 is disposed on the guide rail 10. The motor protection circuit includes an inner limit switch, an outer limit switch, a forward hard limit 220, and a reverse hard limit 210. The inner limit switch includes an inner forward limit switch-LIM1+ and an inner reverse limit switch-LIM1-. The outer limit switch includes an outer forward limit switch-LIM2+ and an outer reverse limit switch-LIM2-.

[0043] As an example, Figure 4 As shown, the positive hard limit 220 is set on the first side of the guide rail 10, and the negative hard limit 210 is set on the second side of the guide rail 10. The outer positive limit switch -LIM2+, the inner positive limit switch -LIM1+, the motor -M1, the inner negative limit switch -LIM1-, ​​and the outer negative limit switch -LIM2- are all set between the positive hard limit 220 and the negative hard limit 210. In this example, the motor protection circuit controls the operation of the motor -M1 based on the signals output when the motor -M1 contacts the inner limit switch, the outer limit switch, the positive hard limit 220, and the negative hard limit 210.

[0044] This embodiment provides a motor protection circuit, such as Figure 1 As shown, it includes a first switch circuit 11, a servo driver -SV1, an outer positive limit switch -LIM2+, an outer negative limit switch -LIM2-, an emergency stop button -SA1 ​​and a safety relay -SR1; the first power supply end of the servo driver -SV1 is connected to an external power supply through the first switch circuit 11, and the output end of the servo driver -SV1 is used to connect to the motor -M1; the outer positive limit switch -LIM2+, the outer negative limit switch -LIM2- and the emergency stop button -SA1 ​​are arranged in series between the first input end and the second input end of the safety relay -SR1; the output end of the safety relay -SR1 is connected to the first switch circuit 11; when any one of the outer positive limit switch -LIM2+, the outer negative limit switch -LIM2- and the emergency stop button -SA1 ​​is triggered, the safety relay -SR1 controls the first switch circuit 11 to disconnect, so that the servo driver -SV1 drives the motor -M1 to stop moving.

[0045] As an example, the external power source can be a three-phase power grid, or other power source for providing power to the motor-M1. The first power supply terminal of the servo driver-SV1 is connected to the external power source through the first switch circuit 11, and the output terminal of the servo driver-SV1 is used to connect the motor-M1 to drive the motor-M1 to work according to the power provided by the external power source. The first switch circuit 11 is used to turn on or turn off the electrical connection between the external power source and the first power supply terminal of the servo driver-SV1.

[0046] As an example, the power equipment operator pre-writes the limit position value of the motor-M1 movement to the internal memory of the servo driver-SV1 through the debugging software of the servo driver-SV1. During the movement of the motor-M1, the servo driver-SV1 controls the motor-M1 to normally decelerate and stop moving when the movement position of the motor-M1 reaches the position corresponding to the limit position value according to the limit position value, so as to respond to abnormal situations such as overload, short circuit, overheating, etc. in time during the operation of the motor-M1, thereby realizing effective motor protection through the soft limit control function. Further, when the soft limit control function fails, the servo driver-SV1 controls the motor-M1 to emergency decelerate and stop moving when the motor-M1 moves to the position corresponding to the inner side forward limit switch-LIM1+ or the inner side reverse limit switch-LIM1-, so as to realize emergency braking of the motor-M1 through the inner side forward limit switch-LIM1+ or the inner side reverse limit switch-LIM1- when the soft limit control function fails, thereby realizing effective motor protection.

[0047] As an example, when the inner side forward limit switch-LIM1+ or the inner side reverse limit switch-LIM1-, and the soft limit control function fail, and the motor-M1 triggers the outer side forward limit switch-LIM2+ or the outer side reverse limit switch-LIM2-, or the operator triggers the emergency stop button-SA1, since the outer side forward limit switch-LIM2+, the outer side reverse limit switch-LIM2- and the emergency stop button-SA1 are connected in series between the first input terminal and the second input terminal of the safety relay-SR1. The output terminal of the safety relay-SR1 is connected to the first switch circuit 11, and the safety relay-SR1 detects the signals output by the outer side forward limit switch-LIM2+, the outer side reverse limit switch-LIM2- and the emergency stop button-SA1, so as to control the first switch circuit 11 to be disconnected, thereby cutting off the external power source, so that the servo driver-SV1 drives the motor-M1 to stop moving.

[0048] It can be understood that in the above embodiment, when the inner limit switch and the outer limit switch both fail, the motor-M1 hits the positive hard limit 220 of the first side of the guide rail 10 or the negative hard limit 210 of the second side of the guide rail 10, forcibly blocks the movement of the motor-M1, and the servo driver-SV1 detects that the motor-M1 torque is overloaded, and sends an alarm and stops providing the motor-M1 driving power to the motor-M1, so that the motor-M1 stops in time.

[0049] In the embodiment, the motor protection circuit includes a first switch circuit 11, a servo driver-SV1, an outer positive limit switch-LIM2+, an outer negative limit switch-LIM2-, an emergency stop button-SA1 and a safety relay-SR1; the first power supply end (L1, L2, L3) of the servo driver-SV1 is connected to an external power supply through the first switch circuit 11, and the output end of the servo driver-SV1 is used to connect the motor-M1; the outer positive limit switch-LIM2+, the outer negative limit switch-LIM2- and the emergency stop button-SA1 are connected in series between the first input end and the second input end of the safety relay-SR1; the output end of the safety relay-SR1 is connected to the first switch circuit 11; when any one of the outer positive limit switch-LIM2+, the outer negative limit switch-LIM2- and the emergency stop button-SA1 is triggered, the safety relay-SR1 controls the first switch circuit 11 to be disconnected, so that the servo driver-SV1 drives the motor-M1 to stop moving; through the linkage of the outer positive limit switch-LIM2+, the outer negative limit switch-LIM2- and the emergency stop button-SA1, when any one of the outer positive limit switch-LIM2+, the outer negative limit switch-LIM2- and the emergency stop button-SA1 is triggered, the safety relay-SR1 can control the first switch circuit 11 to be disconnected, so that the servo driver-SV1 drives the motor-M1 to stop moving, and further when any one of the outer positive limit switch-LIM2+, the outer negative limit switch-LIM2- and the emergency stop button-SA1 fails, the other normal elements can be normally triggered, so that the servo driver-SV1 drives the motor-M1 to stop moving in time, and the safety of the motor-M1 in the running process is improved.

[0050] In an embodiment, as Figure 2As shown, the number of the emergency stop buttons-SA1 is two; the first safety contact of the outer positive limit switch-LIM2+, the first safety contact of the outer negative limit switch-LIM2- and one of the emergency stop buttons-SA1 are connected in series between the first input end and the second input end of the safety relay-SR1; the second safety contact of the outer positive limit switch-LIM2+, the second safety contact of the outer negative limit switch-LIM2- and the other of the emergency stop buttons-SA1 are connected in series between the third input end and the fourth input end of the safety relay-SR1.

[0051] Wherein, the outer positive limit switch-LIM2+ and the outer negative limit switch-LIM2- are double-pole single-throw switches. The first safety contact (11, 12) and the second safety contact (21, 22) of the outer positive limit switch-LIM2+, and the first safety contact (11, 12) and the second safety contact (21, 22) of the outer negative limit switch-LIM2- are all normally closed contacts.

[0052] As an example, when the motor-M1 triggers the outer forward limit switch-LIM2+ and the outer reverse limit switch-LIM2-, and the operator triggers any one of the emergency stop buttons-SA1, the first safety contact of the outer forward limit switch-LIM2+, the first safety contact of the outer reverse limit switch-LIM2- and one of the emergency stop buttons-SA1 are arranged in series between the first input end and the second input end of the safety relay-SR1, forming a closed loop, and the second safety contact of the outer forward limit switch-LIM2+, the second safety contact of the outer reverse limit switch-LIM2- and another of the emergency stop buttons-SA1 are arranged in series between the third input end and the fourth input end of the safety relay-SR1, forming another closed loop, and the triggered element disconnects the closed loop in which it is located, and the safety relay-SR1 detects the corresponding closed loop disconnection through the first input end and the second input end, or the third input end and the fourth input end, thereby timely controlling the first switch circuit 11 to disconnect, and then cutting off the external power supply. In this example, two emergency stop buttons -SA1 ​​are set, and the first safety contact of the outer positive limit switch -LIM2+, the first safety contact of the outer reverse limit switch -LIM2- and one of the emergency stop buttons -SA1 ​​are set in series between the first input terminal and the second input terminal of the safety relay -SR1; the second safety contact of the outer positive limit switch -LIM2+, the second safety contact of the outer reverse limit switch -LIM2- and the other emergency stop button -SA1 ​​are set in series between the third input terminal and the fourth input terminal of the safety relay -SR1. Between the input ends, two closed loops are formed between the two emergency stop buttons -SA1 ​​and the safety contacts of the outer positive limit switch -LIM2+ and the outer reverse limit switch -LIM2-, namely the first safety contact and the second safety contact, and the safety relay -SR1. When one of the emergency stop buttons -SA1 ​​or any one of the first safety contact and the second safety contact fails, the normal emergency stop button -SA1 ​​and safety contacts can be triggered normally, realizing redundant control of the motor -M1 and improving the reliability and safety of the motor -M1 during operation.

[0053] In one embodiment, if Figure 3 As shown, the first switching circuit 11 includes a contactor-KM1; the contactor-KM1 includes main contacts (1-6) and a first coil (A1, A2); the main contacts are connected to the external power supply and the first power supply terminal of the servo driver-SV1; the first coil (A1, A2) is connected to the first power supply terminal (24V) and the safety relay-SR1, and is used to control the main contacts (1-6) to operate under the control of the safety relay-SR1.

[0054] The first power supply end is used to supply an electric signal to the first coil. The first power supply end can be a Figure 3 The output end of the switching power supply-PW1.

[0055] As an example, the first coil (A1, A2) is connected in series between the first power supply end and the ground through the output contact (23, 24) of the safety relay-SR1. The output contact (23, 24) is a normally open contact. When the motor-M1 works normally, the main contact is closed. When any one of the outside forward limit switch-LIM2+, the outside reverse limit switch-LIM2- and the emergency stop button-SA1 is triggered, the safety relay-SR1 controls the output contact (23, 24) to be closed, the first coil is powered, and the main contact of the contactor-KM1 is opened, so as to cut off the external power supply and stop the motor-M1 from working. When the motor-M1 is abnormal, the output contact (23, 24) can be reset to the open state by resetting the safety relay-SR1, the first coil is powered off, the main contact of the contactor-KM1 is closed again, the first power supply end of the servo driver-SV1 is connected to the external power supply, and the motor-M1 works normally.

[0056] In the embodiment, the contactor-KM1 includes the main contact (1-6) and the first coil. The main contact is connected to the external power supply and the first power supply end of the servo driver-SV1, and the first coil is connected to the first power supply end and the safety relay-SR1. The first coil is used to control the main contact to work under the control of the safety relay-SR1, so as to control the on-off between the external power supply and the servo driver-SV1. The contactor-KM1 has high reliability, simple structure and low cost of the first switching circuit 11.

[0057] In an embodiment, the motor protection circuit further includes a switching power supply-PW1. The input end of the switching power supply-PW1 is used to connect the external power supply, and the output end of the switching power supply-PW1 is connected to the contactor-KM1, the second power supply end (24VDC, 0VDC) of the servo driver-SV1 and the third power supply end (A1, A2) of the safety relay-SR1.

[0058] As an example, the input end of the switching power supply-PW1 is used to connect the external power supply, the output end of the switching power supply-PW1 is connected with the contactor-KM1, the second power supply end of the servo driver-SV1 and the third power supply end of the safety relay-SR1, used to convert the voltage signal output by the external power supply, output the voltage conversion signal to the contactor-KM1, the second power supply end of the servo driver-SV1 and the third power supply end of the safety relay-SR1, so as to supply power to the first coil of the contactor-KM1, the servo driver-SV1 and the safety relay-SR1, so as to ensure that the contactor-KM1, the servo driver-SV1 and the safety relay-SR1 can work stably.

[0059] As an example, the external power supply is connected with the switching power supply-PW1 through the first air switch QF1 and the second air switch QF2. The external power supply is connected with the first switching circuit 11 through the first air switch QF1 and the third air switch QF3. To ensure the safety of the external power supply when supplying power to the switching power supply-PW1 and the first switching circuit 11.

[0060] As an example, the output end of the switching power supply-PW1 is also provided with a fuse F1 between the contactor-KM1, the second power supply end of the servo driver-SV1 (24VDC, 0VDC) and the third power supply end of the safety relay-SR1 (A1, A2), so as to timely disconnect the electrical connection between the output end of the switching power supply-PW1 and the contactor-KM1, the second power supply end of the servo driver-SV1 and the third power supply end of the safety relay-SR1 when the current is too large.

[0061] In this embodiment, the switching power supply-PW1 takes power from the external power supply and converts the electrical signal provided by the external power supply to provide a stable voltage conversion signal, ensuring the stability of the contactor-KM1, the servo driver-SV1 and the safety relay-SR1.

[0062] In an embodiment, the motor protection circuit further comprises an inner limit switch; the inner limit switch is connected with the servo driver-SV1; when the inner limit switch is triggered by the motor-M1, the signal output by the inner limit switch controls the servo driver-SV1 to drive the motor-M1 to stop moving.

[0063] In the embodiment, when the soft limit control function of the servo driver-SV1 fails, the safety of the motor-M1 during movement is improved by detecting whether the inner limit switch is triggered by the motor-M1. Meanwhile, when the inner limit switch fails, the motor-M1 is stopped by triggering any one of the outer positive limit switch-LIM2+, the outer negative limit switch-LIM2- and the emergency stop button-SA1, thereby achieving multiple protection of the motor-M1.

[0064] In an embodiment, the inner limit switch includes an inner positive limit switch-LIM1+ and an inner negative limit switch-LIM1-. The first safety contact and the second safety contact of the inner positive limit switch-LIM1+ are connected in series between the output of the switching power supply-PW1 and the first control terminal of the servo driver-SV1. The first safety contact and the second safety contact of the inner negative limit switch-LIM1- are connected in series between the output of the switching power supply-PW1 and the second control terminal of the servo driver-SV1.

[0065] In the embodiment, the first safety contact (11, 12) and the second safety contact (21, 22) of the inner positive limit switch-LIM1+ and the first safety contact (11, 12) and the second safety contact (21, 22) of the inner negative limit switch-LIM1- are both normally closed contacts.

[0066] In the embodiment, the first safety contact and the second safety contact of the inner positive limit switch-LIM1+ are connected in series between the output of the switching power supply-PW1 and the first control terminal of the servo driver-SV1. The first safety contact and the second safety contact of the inner negative limit switch-LIM1- are connected in series between the output of the switching power supply-PW1 and the second control terminal of the servo driver-SV1. When the inner positive limit switch-LIM1+ or the inner negative limit switch-LIM1- is triggered, any one of the first safety contact and the second safety contact of the inner positive limit switch-LIM1+ or the inner negative limit switch-LIM1- can output a control signal to the first control terminal or the second control terminal of the servo driver-SV1, so that the servo driver-SV1 controls the motor-M1 to stop working according to the control signal output by any one of the safety contacts, thereby realizing redundant control of the motor-M1 and improving the safety of the motor-M1 when any one of the first safety contact and the second safety contact fails.

[0067] In an embodiment, the motor protection circuit further comprises a reset switch -SB1; the reset switch -SB1 is arranged in series between the fifth input end S34 and the sixth input end S12 of the safety relay -SR1 and the contactor -KM1, for resetting the safety relay -SR1.

[0068] In the embodiment, the reset switch -SB1 is arranged in series between the fifth input end S34 and the sixth input end S12 of the safety relay -SR1 and the contactor -KM1, for resetting the safety relay -SR1, so that after the motor -M1 recovers from the abnormality, the reset switch -SB1 reconnects the contactor -KM1 to the external power supply and the servo driver -SV1, to ensure that the motor -M1 works in time after recovering from the abnormality.

[0069] In an embodiment, the normally closed contact (3, 4) of the reset switch -SB1 is connected in series between the fifth input end S34 and the sixth input end S12 of the safety relay -SR1 and the auxiliary normally closed contact (11, 12) of the contactor -KM1; the normally open contact (X1, X2) of the reset switch -SB1 is connected in series on the second power supply end of the servo driver -SV1 and the auxiliary normally open contact (13, 14) of the contactor -KM1.

[0070] As an example, in the initial state of the motor protection circuit, i.e. when the power equipment is not started, the auxiliary normally closed contacts (11, 12) of the contactor-KM1 are closed, the auxiliary normally open contacts (13, 14) are open, the fifth input end S34 and the sixth input end S12 of the safety relay-SR1 form a closed loop through the normally closed contacts (3, 4) of the reset switch-SB1 and the auxiliary normally closed contacts (11, 12) of the contactor-KM1, the output contacts (23, 24) of the safety relay-SR1 are closed, the first coil of the contactor-KM1 is powered, the main contacts of the contactor-KM1 are open, the external power supply is cut off, and the motor-M1 is not powered. When resetting is needed, the operator presses the reset switch-SB1, the normally closed contacts (3, 4) of the reset switch-SB1 are open, the closed loop between the fifth input end S34 and the sixth input end S12 of the safety relay-SR1 is broken, the control output contacts (23, 24) of the safety relay-SR1 are open, the first coil of the contactor-KM1 is de-energized, and the contactor-KM1 releases, returning its auxiliary normally closed contacts (11, 12) and auxiliary normally open contacts (13, 14) to the initial state. After the reset operation, the operator releases the reset switch-SB1, and its output contacts (23, 24) are re-closed. Since the auxiliary normally closed contacts (11, 12) of the contactor-KM1 are closed, a closed circuit is again formed between the fifth input end S34 and the sixth input end S12 of the safety relay-SR1, and the safety relay-SR1 is reactivated. The output contacts (23, 24) of the safety relay-SR1 are closed, the first coil of the contactor-KM1 is powered again, and the contactor-KM1 is attracted, with its main contacts closed, reconnecting the external power supply to the servo driver-SV1 to control the motor-M1 to continue running.

[0071] In this embodiment, the normally closed contacts of the reset switch-SB1 are connected in series between the fifth input end S34 and the sixth input end S12 of the safety relay-SR1 and the auxiliary normally closed contacts of the contactor-KM1, and the normally open contacts of the reset switch-SB1 are connected in series with the auxiliary normally open contacts of the contactor-KM1 on the second power supply end of the servo driver-SV1, to ensure that the motor protection circuit can be normally reset after the motor-M1 abnormally operates, improving the reliability of the motor protection circuit.

[0072] In an embodiment, a filter-FILT1 is further provided between the first power supply end of the servo driver-SV1 and the first switch circuit 11. In this embodiment, a filter-FILT1 is further provided between the first power supply end of the servo driver-SV1 and the first switch circuit 11, which is used to filter the voltage signal output by the first switch circuit 11 to ensure that the servo driver-SV1 provides stable power to the motor-M1.

[0073] The motor protection system comprises a guide rail 10 and the motor protection circuit, the outer positive limit switch LIM2+ and the outer negative limit switch LIM2- are arranged on the guide rail 10 respectively, and the motor M1 is arranged between the outer positive limit switch LIM2+ and the outer negative limit switch LIM2-; when any one of the outer positive limit switch LIM2+, the outer negative limit switch LIM2- and the emergency stop button SA1 is triggered, the safety relay SR1 controls the first switch circuit 11 to be disconnected, so that the servo driver SV1 drives the motor M1 to stop moving.

[0074] In the embodiment, the outer positive limit switch LIM2+ and the outer negative limit switch LIM2- are arranged on the guide rail 10 respectively, and the motor M1 is arranged between the outer positive limit switch LIM2+ and the outer negative limit switch LIM2-, so that when the motor M1 triggers the outer positive limit switch LIM2+ and the outer negative limit switch LIM2- on the guide rail 10, or the emergency stop button SA1 is triggered, that is, when any one of the outer positive limit switch LIM2+, the outer negative limit switch LIM2- and the emergency stop button SA1 is triggered, the safety relay SR1 controls the first switch circuit 11 to be disconnected, so that the servo driver SV1 drives the motor M1 to stop moving, and when any one of the outer positive limit switch LIM2+, the outer negative limit switch LIM2- and the emergency stop button SA1 is faulty, the other normal elements can be triggered normally, so that the servo driver SV1 drives the motor M1 to stop moving in time, and the safety of the motor M1 during operation is improved.

[0075] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. An electric motor protection circuit, characterized in that, The motor protection circuit comprises a first switch circuit, a servo driver, an outer positive limit switch, an outer negative limit switch, an emergency stop button and a safety relay; A first power supply end of the servo driver is connected with an external power supply through the first switch circuit, and an output end of the servo driver is used for connecting a motor; The outer positive limit switch, the outer negative limit switch and the emergency stop button are arranged in series between a first input end and a second input end of the safety relay; An output end of the safety relay is connected with the first switch circuit; When any one of the outer positive limit switch, the outer negative limit switch and the emergency stop button is triggered, the safety relay controls the first switch circuit to be disconnected, so that the servo driver drives the motor to stop moving.

2. The motor protection circuit of claim 1, wherein, The number of the emergency stop buttons is two; First safety contacts of the outer positive limit switch and the outer negative limit switch are arranged in series between the first input end and the second input end of the safety relay with one of the emergency stop buttons; Second safety contacts of the outer positive limit switch and the outer negative limit switch are arranged in series between a third input end and a fourth input end of the safety relay with another of the emergency stop buttons.

3. The motor protection circuit of claim 1, wherein, The first switch circuit comprises a contactor, and the contactor comprises main contacts and a first coil; The main contacts are connected with the external power supply and the first power supply end of the servo driver; The first coil is connected with a first power supply end and the safety relay, and is used for controlling the main contacts to work under the control of the safety relay.

4. The motor protection circuit of claim 3, wherein, The motor protection circuit further comprises a switching power supply; An input end of the switching power supply is used for connecting the external power supply, and an output end of the switching power supply is connected with the contactor, a second power supply end of the servo driver and a third power supply end of the safety relay.

5. The motor protection circuit of claim 4, wherein, The motor protection circuit further comprises an inner limit switch, and the inner limit switch is connected with the servo driver; When the inner limit switch is triggered by the motor, a signal output by the inner limit switch controls the servo driver to drive the motor to stop moving.

6. The motor protection circuit of claim 5, wherein, The inner limit switch comprises an inner positive limit switch and an inner negative limit switch; First safety contacts and second safety contacts of the inner positive limit switch are arranged in series between the output end of the switching power supply and a first control end of the servo driver; First safety contacts and second safety contacts of the inner negative limit switch are arranged in series between the output end of the switching power supply and a second control end of the servo driver.

7. The motor protection circuit of claim 3, wherein, The motor protection circuit further comprises a reset switch; The reset switch is arranged in series between a fifth input end and a sixth input end of the safety relay with the contactor, and is used for resetting the safety relay.

8. The motor protection circuit of claim 7, wherein, A normally closed contact of the reset switch and an auxiliary normally closed contact of the contactor are arranged in series between the fifth input end and the sixth input end of the safety relay; A normally open contact of the reset switch and an auxiliary normally open contact of the contactor are arranged in series on the second power supply end of the servo driver.

9. The motor protection circuit of claim 1, wherein, A filter is further arranged between the first power supply end of the servo driver and the first switch circuit.

10. An electric machine protection system, characterized in that The motor protection circuit according to any one of claims 1 to 9, comprising a guide rail and the motor protection circuit; the outer positive limit switch and the outer negative limit switch are arranged on the guide rail, and the motor is arranged between the outer positive limit switch and the outer negative limit switch. When any one of the outer positive limit switch, the outer negative limit switch and the emergency stop button is triggered, the safety relay controls the first switch circuit to be disconnected, so that the servo driver drives the motor to stop moving.

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