Linear motor protection circuit, linear motor protection system and protection method thereof

Abstract

The present invention relates to the field of motor control technology, and specifically to a linear motor protection circuit, a linear motor protection system and a protection method thereof, wherein a positive hard limit is set at the first end of a linear guide rail, and a positive limit is set at the first side of the linear guide rail. The positive protection limit is set between the positive hard limit and the positive limit, and when the positive limit is triggered by the linear motor, the signal output by the positive limit controls the servo driver to drive the linear motor to decelerate; when the positive protection limit is triggered by the linear motor, the signal output by the positive protection limit controls the servo driver to drive the linear motor to stop moving. In this way, when the limit fails, the protection limit is used to perform an emergency stop movement, thereby preventing the linear motor from hitting the mechanical hard limit with power and avoiding damage to the motor.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a linear motor protection circuit, a linear motor protection system and a protection method thereof. Background Art

[0002] In the field of motor control, linear motors have the characteristics of large thrust and fast acceleration and deceleration. In pursuit of faster and more precise motion control, linear motors are increasingly used. However, unlike the large friction of the screw drive structure of the rotary motor, in actual application scenarios, the inventors found that when a linear motor fails, especially when the limit fails and the linear motor hits the hard limit, it is easy to damage the linear motor and may cause safety accidents. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a linear motor protection circuit, a linear motor protection system and a protection method thereof in view of the above-mentioned defects of the prior art, so as to solve the safety problem when a linear motor fails.

[0004] A linear motor protection circuit comprises a servo power supply control circuit and a servo drive circuit connected thereto; wherein the servo drive circuit comprises a servo drive, and a linear motor, a positive limit and a positive protection limit respectively connected to the servo drive;

[0005] The servo power supply control circuit is used to provide servo drive power to the servo driver based on an input external power supply;

[0006] The servo driver is used to drive the linear motor to move based on the servo drive power supply;

[0007] When the positive limit is triggered by the linear motor, the signal output by the positive limit controls the servo driver to drive the linear motor to decelerate;

[0008] When the forward protection limit is triggered by the linear motor, the signal output by the forward protection limit controls the servo driver to drive the linear motor to stop moving.

[0009] In one of the embodiments, the servo drive circuit further includes a reverse limit and a reverse protection limit respectively connected to the servo drive;

[0010] When the reverse limit is triggered by the linear motor, the signal output by the reverse limit controls the servo driver to drive the linear motor to decelerate;

[0011] When the reverse protection limit is triggered by the linear motor, the signal output by the reverse protection limit controls the servo driver to drive the linear motor to stop moving.

[0012] In one embodiment, the linear motor protection circuit further includes an external power supply circuit connected to the servo power supply control circuit, and the external power supply circuit provides external power to the servo power supply control circuit.

[0013] In one of the embodiments, the external power supply circuit includes: a power cord, a circuit breaker, a filter and a surge protector for providing external power;

[0014] The first end of the circuit breaker is connected to the power line, the second end of the circuit breaker is connected to the first end of the filter, and the second end of the filter is connected to the servo power supply control circuit;

[0015] The surge protector is connected to the first end of the filter and the second end of the circuit breaker respectively.

[0016] In one of the embodiments, the servo power supply control circuit includes a servo start button, a servo stop button, a first coil and a first normally open contact;

[0017] The servo start button, the servo stop button and the first coil are connected in series and then in parallel to the output end of the external power supply circuit;

[0018] The first normally open contact is respectively connected to the output end of the external power supply circuit and the input end of the servo drive circuit.

[0019] In one of the embodiments, the servo power supply control circuit further includes an emergency stop button switch, a second coil and a second normally open contact;

[0020] The first normally open contact, the forward protection limit, the reverse protection limit, the emergency stop button switch, and the second coil are connected in series and then in parallel to the output end of the external power supply circuit;

[0021] The second normally open contact is respectively connected to the output end of the external power supply circuit and the input end of the servo drive circuit.

[0022] In one embodiment, the servo power supply control circuit further includes a servo alarm light, and the servo drive circuit further includes a third coil and a first switch;

[0023] The third coil is connected to the servo driver, and the first switch and the servo alarm light are connected in series and then in parallel to the output end of the external power supply circuit.

[0024] A linear motor protection system comprises a linear guide rail and the above-mentioned linear motor protection circuit, wherein the linear motor is arranged on the linear guide rail;

[0025] The servo driver drives the linear motor to move along the linear guide rail;

[0026] The positive limit is arranged on the first side of the linear guide rail; when the linear motor moves to trigger the positive limit, the signal output by the positive limit is used to control the servo driver to drive the linear motor to decelerate;

[0027] The forward protection limit is arranged beside the forward limit; wherein, when the linear motor moves out of the forward limit and moves to trigger the forward protection limit, the signal output by the forward protection limit is used to control the servo drive to drive the linear motor to stop moving.

[0028] In one of the specific embodiments, the linear motor protection system further includes a positive hard limit and a reverse hard limit provided on the linear guide rail;

[0029] The positive hard limit is arranged at the first end of the linear guide rail; the positive protection limit is arranged between the positive hard limit and the positive limit;

[0030] The reverse hard limit is arranged at the second end of the linear guide rail;

[0031] The reverse limit is arranged on the second side of the linear guide rail; when the linear motor moves to trigger the reverse limit, the signal output by the reverse limit is used to control the servo driver to drive the linear motor to decelerate;

[0032] The reverse protection limit is set between the reverse hard limit and the reverse limit; wherein, when the linear motor moves to trigger the reverse protection limit, the signal output by the reverse protection limit is used to control the servo drive to drive the linear motor to stop moving.

[0033] A linear motor protection method is applied to the above linear motor protection circuit or the above linear motor protection system, the method comprising:

[0034] When the linear motor moves forward to trigger the positive limit, the servo driver is controlled to drive the linear motor to decelerate, and the positive movement is moving toward the position of the positive limit;

[0035] If the linear motor does not stop moving when it moves to the forward protection limit and triggers the forward protection limit, the servo driver is controlled to drive the linear motor to stop moving, and the servo drive power input to the servo driver is disconnected.

[0036] In one specific embodiment, the method further comprises:

[0037] When the linear motor moves in the reverse direction to trigger the reverse limit, the servo driver is controlled to drive the linear motor to decelerate, and the reverse movement is movement toward the position of the reverse limit;

[0038] If the linear motor does not stop moving when it moves to the reverse protection limit and triggers the reverse protection limit, the servo driver is controlled to drive the linear motor to stop moving, and the servo drive power input to the servo driver is disconnected.

[0039] In one specific embodiment, the method further comprises:

[0040] If the positive limit is set on the second side of the linear guide rail, and the reverse limit is set on the first side of the linear guide rail;

[0041] When the linear motor moves forward to trigger the forward protection limit, the servo driver is controlled to drive the linear motor to stop moving, and the servo drive power input to the servo driver is disconnected;

[0042] When the linear motor moves in the reverse direction to trigger the reverse protection limit, the servo driver is controlled to drive the linear motor to stop moving, and the servo drive power input to the servo driver is disconnected.

[0043] In the above linear motor protection circuit, system and control method, when the positive limit is triggered by the linear motor, the signal output by the positive limit can control the servo driver to drive the linear motor to decelerate; when the positive protection limit is triggered by the linear motor, the signal output by the positive protection limit can control the servo driver to drive the linear motor to stop moving. Therefore, when the limit fails, the protection limit is used to perform an emergency stop movement, thereby preventing the linear motor from colliding with the mechanical hard limit with power, avoiding damage to the motor, and effectively ensuring the safety of the operator. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0046] Figure 1is a schematic diagram of a linear motor protection circuit of the present invention;

[0047] Figure 2 It is a structural schematic diagram of a linear motor protection device and a control method thereof of the present invention;

[0048] Figure 3 It is a schematic diagram of the steps of the linear motor protection device and the control method thereof of the present invention. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] It should be understood that the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and fully convey the scope of the present invention to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0051] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to, connected to, or coupled to other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on, directly adjacent to, directly connected to, directly connected to, or directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or part from another element, component, region, layer, or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer, or part discussed below may be represented as a second element, component, region, layer, or part.

[0052] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that the spatially relative terms are intended to include different orientations of the device in use and operation in addition to the orientations shown in the figures. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0053] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "a", "an" and " / the" are also intended to include plural forms, unless the context clearly indicates another way. It should also be understood that the terms "consisting of" and / or "comprising" when used in this specification determine the presence of features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0054] In order to fully understand the present invention, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed by the present invention. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0055] In the field of motor control, linear motors have the characteristics of large thrust and fast acceleration and deceleration. In pursuit of faster and more precise motion control, linear motors are increasingly used. However, unlike the large friction of the screw drive structure of the rotary motor, in actual application scenarios, the inventors found that when a linear motor fails, especially when the limit structure fails, for example, when the linear motor hits the limit structure, it is easy to cause damage to the linear motor. In addition, the linear motor may rush to the limit structure with power or even rush out of the limit structure, causing a safety accident. In order to solve the above problems, the invention concept of this application was conceived, which will be specifically combined with the attached Figure 1 -Attached Figure 3 , and are illustrated by the following examples.

[0056] The present invention provides a linear motor protection circuit, which includes a servo power supply control circuit and a servo drive circuit connected thereto. The servo drive circuit includes a servo drive, and a linear motor, a positive limit and a positive protection limit respectively connected to the servo drive.

[0057] The servo power supply control circuit is used to provide servo drive power to the servo drive based on an input external power supply.

[0058] The servo drive is used to drive the linear motor to move along the linear guide based on a servo drive power supply.

[0059] When the positive limit is triggered by the linear motor, the signal output by the positive limit controls the servo driver to drive the linear motor to decelerate.

[0060] When the positive protection limit is triggered by the linear motor, the signal output by the positive protection limit controls the servo driver to drive the linear motor to stop moving.

[0061] Therefore, the above-mentioned linear motor protection circuit performs emergency stop movement through the protection limit when the limit fails, thereby preventing the linear motor from hitting the mechanical hard limit with power, avoiding damage to the motor, and effectively ensuring the safety of the operator.

[0062] It should be noted that the “positive direction” of the “positive limit” and “positive protection limit” described in the above embodiments may specifically be the movement direction in which the linear motor is configured to be guided.

[0063] In one specific embodiment, Figure 1 As shown, Figure 1is a schematic diagram of a linear motor protection circuit in one embodiment. The linear motor protection circuit includes an external power supply circuit 100, a servo power supply control circuit 200 and a servo drive circuit 300. Among them, the external power supply circuit 100 specifically includes a circuit breaker 101, a surge protector 102 and a filter 103. The servo power supply control circuit 200 specifically includes a servo start button 201 (a reset button), a first coil 202a, a first normally open contact 202b (wherein the first coil 202a and the first normally open contact 202b constitute a control contactor), a servo stop button 203 (a reset button), a servo alarm light 204, an emergency stop button switch 205 (a self-locking button), a second coil 206a and a second normally open contact 206b (wherein the second coil 206a and the second normally open contact 206b constitute a drive contactor). The servo drive circuit 300 specifically includes a servo driver 301, a linear motor 302, an encoder 303, a third coil 304a and a first switch 304b (wherein the third coil 304a and the first switch 304b constitute a servo alarm relay), a forward limit 305, a reverse limit 306, a forward protection limit 307 and a reverse protection limit 308.

[0064] Wherein, the first end of the circuit breaker 101 is connected to the power line, and the second end of the circuit breaker 101 serves as the output end of the external power supply circuit. The circuit breaker 101 is used to perform overcurrent protection on the servo power supply control circuit 200 and the servo drive circuit 300. The surge protector 102 is connected to the first end of the filter 103 and the second end of the circuit breaker 101 respectively. The surge protector 102 is used to protect the servo power supply control circuit 200 and the servo drive circuit 300 from sudden external peak current or voltage interference. The first end of the filter 103 is connected to the second end of the circuit breaker 101, and the second end of the filter 103 serves as the output end of the external power supply circuit. The filter 103 is used to effectively filter out the frequency point of a specific frequency in the power line or the frequency other than the frequency point to obtain a power signal of a specific frequency, or eliminate a power signal after eliminating a specific frequency.

[0065] The first normally open contact 202b, the forward protection limit 307, the reverse protection limit 308, the emergency stop button switch 205 and the second coil 206a are connected in series and then connected in parallel to the output end of the external power supply circuit 100; the second normally open contact 206b is respectively connected to the output end of the external power supply circuit 100 and the input end of the servo drive circuit 300. When the first coil 202a, the forward protection limit 307, the reverse protection limit 308 and the emergency stop button switch 205 are all connected, the second coil 206a is energized, so that the second normally open contact 206b is connected, thereby supplying servo drive power to the servo driver 301. When an emergency occurs in the linear motor protection system, the emergency stop button switch 205 is disconnected, the second coil 206a is not energized, and the second normally open contact 206b is disconnected, thereby shutting off the servo drive power input to the servo driver 301.

[0066] The servo start button 201, the servo stop button 203 and the first coil 202a are connected in series and then connected in parallel to the output end of the external power supply circuit 100. The first normally open contact 202b is respectively connected to the output end of the external power supply circuit 100 and the input end of the servo drive circuit 300. When the linear motor protection system needs to work normally, the servo start button 201 and the servo stop button 203 are connected, the first coil 202a is energized, and the first normally open contact 202b is connected, thereby supplying servo control power to the servo driver 301. In addition, the two ends of the servo start button 201 are also connected in parallel to the third normally open contact 202b, and the third normally open contact 202b is used to self-lock the provided servo control power after the servo start button 201 is pressed. In addition, when the operator needs to actively shut down the linear motor protection system, the servo stop button 203 is disconnected, the first coil 202a is not energized, and the first normally open contact 202b is disconnected, thereby shutting down the servo control power supply of the input servo driver 301, and shutting down the servo drive power supply of the input servo driver 301 through the drive contactor.

[0067] The third coil 304a is connected to the servo driver 301, and the first switch 304b and the servo alarm light 204 are connected in series and then in parallel to the output end of the external power supply circuit 100. The servo alarm relay is used to control the servo alarm light 204 to display the working status of the servo driver 301, for example, the light turns on to indicate that the servo driver 301 is in alarm, and the light turns off to indicate that the servo driver 301 is working normally.

[0068] The servo driver 301 receives externally input servo control power and servo drive power, and drives the linear motor 302 to move with the assistance of the encoder 303. The servo drive power is used to drive the linear motor 302 to move, and the servo control power is used to control the motion parameters of the linear motor 302, including parameters such as motion direction, motion distance and motion speed.

[0069] One end of the forward limit 305, the reverse limit 306, the forward protection limit 307 and the reverse protection limit 308 are all connected to the servo driver 301, and the other ends are all grounded. When the linear motor 302 moves forward and hits the forward limit 305, if the forward limit 305 works normally, the forward limit 305 is triggered, and the low-level signal output by the forward limit 305 is input into the servo driver 301, and the servo driver 301 drives the linear motor 302 to decelerate until it stops moving; if the forward limit 305 fails or the linear motor 302 has too much inertia to stop in time, when the linear motor 302 runs to the forward protection limit 307, the forward protection limit 307 turns off the servo drive power input to the servo driver 301 through the driving contactor, and the low-level signal output by the forward protection limit 307 is input into the servo driver 301, so that the linear motor 302 is urgently decelerated until it stops moving, and the driver 301 also outputs an alarm signal. Similarly, when the linear motor 302 moves in the reverse direction and hits the reverse limit 306, if the reverse limit 306 works normally and is triggered, the low-level signal output by the reverse limit 306 is input into the servo driver 301, and the servo driver 301 drives the linear motor 302 to decelerate until it stops moving; if the reverse limit 306 fails or the linear motor 302 has too much inertia to stop in time, when the linear motor 302 runs to the reverse protection limit 308, the reverse protection limit 308 turns off the servo drive power input to the servo driver 301 through the driving contactor, and the low-level signal output by the reverse protection limit 308 is input into the servo driver 301, so that the linear motor 302 decelerates urgently until it stops moving. At the same time, the driver 302 outputs an alarm signal for prompting.

[0070] In addition, the present invention also provides a linear motor protection system, including a positive hard limit, a linear guide rail and the above-mentioned linear motor protection circuit.

[0071] Wherein, the servo driver drives the linear motor to move along the linear guide rail;

[0072] The positive limit is set on the first side of the linear guide rail. When the linear motor moves to trigger the positive limit, the signal output by the positive limit is used to control the servo driver to drive the linear motor to decelerate.

[0073] The positive protection limit is set on the side of the positive hard limit. This side is the side to which the linear motor continues to move in the original direction after passing the positive limit. When the linear motor moves out of the positive limit and moves to trigger the forward protection limit, the signal output by the forward protection limit is used to control the servo drive to drive the linear motor to stop moving.

[0074] The present invention designs a protection system for the linear motor, and performs emergency stop movement through the protection limit when the limit fails, thereby preventing the linear motor from hitting the mechanical hard limit with power, avoiding damage to the motor, and effectively ensuring the safety of the operator.

[0075] In a specific embodiment, Figure 2 1 is a schematic diagram of the structure of a linear motor protection system in an embodiment of the present invention. In this embodiment, the linear motor protection system includes: a linear guide rail 10, a positive hard limit 210, a reverse hard limit 220, a positive protection limit 310, a reverse protection limit 320, a positive limit 410, a reverse limit 420, a load 50, a linear motor 60 and a marble 70.

[0076] The linear guide 10 is installed on the marble 70 to provide guidance for the linear motor 60. The linear motor 60 carries the load 50. The servo driver is arranged on the linear motor 60 to drive the linear motor 60 to move on the linear guide 10. The positive hard limit 210 is arranged at the first end of the linear guide 10, and the reverse hard limit 220 is arranged at the second end of the linear guide 10. The positive limit 410 and the reverse limit 420 are installed within the effective design stroke on both sides of the linear guide 10, wherein the positive limit 410 is arranged on the first side of the linear guide 10, and the reverse limit 420 is arranged on the second side of the linear guide 10. Figure 2 As shown, the first side is close to the first end, and the second side is close to the second end. When the linear motor 60 moves to trigger the positive limit 410, the signal output by the positive limit 410 is input into the servo driver, and the servo driver controls the linear motor 60 to decelerate until it stops moving. Similarly, when the linear motor 60 moves to trigger the reverse limit 420, the signal output by the reverse limit 420 is input into the servo driver, and the servo driver controls the linear motor 60 to decelerate until it stops moving.

[0077] The forward protection limit 310 is set between the forward hard limit 210 and the forward limit 410, and can be installed at a position 5 mm away from the outside of the forward limit 410. The reverse protection limit 320 is set between the reverse hard limit 220 and the reverse limit 420, and can be installed at a position 5 mm away from the outside of the reverse limit 420. Of course, it can also be other positions. Users can set it according to actual needs, and no specific restrictions are made here. When the linear motor 60 moves through the forward limit 410, if the forward limit 410 fails, or because the inertia of the linear motor 60 is too large to stop in time and rush through the forward limit 410 to move to the forward protection limit 310, the signal output by the forward protection limit 310 is input into the servo driver, and the servo driver controls the linear motor 60 to stop moving urgently and cuts off the servo drive power input of the servo driver. Similarly, when the linear motor 60 moves through the reverse limit 420, if the reverse limit 420 fails, or the linear motor 60 has too much inertia to stop in time and passes through the reverse limit 420 to move to the reverse protection limit 320, the signal output by the reverse protection limit 320 is input into the servo driver, and the servo driver controls the linear motor 60 to stop moving urgently and cuts off the servo drive power input of the servo driver.

[0078] In this way, even if the linear motor 60 carrying the load 50 hits the forward hard limit 210 or the reverse hard limit 220 due to inertia, since the servo drive power supply has been cut off, the forward hard limit 210 or the reverse hard limit 220 can no longer be damaged. At this time, the risk of rushing out of the hard limit has been basically eliminated.

[0079] It should be noted that the "forward" and "reverse" examples used in the above embodiments are only descriptions of scenarios in one implementation. In actual scenarios, multiple other directions may be involved. For example, the direction in which a linear motor may fail and move is also included in other embodiments of the present application. To avoid redundancy, the description will not be expanded here.

[0080] Furthermore, the present invention also provides a linear motor protection method, wherein: Figure 3 is a schematic diagram of a linear motor protection method in an embodiment, wherein the steps include:

[0081] Step 302: When the linear motor moves forward to trigger the forward limit, the servo driver is controlled to drive the linear motor to decelerate.

[0082] Among them, the positive motion is the motion towards the positive limit position. When the linear motor moves forward and hits the positive limit, if the positive limit works normally, the positive limit is triggered, and the low-level signal output by the positive limit is input into the servo driver, and the servo driver drives the linear motor to decelerate until it stops moving, and outputs an alarm signal.

[0083] Step 304: If the linear motor does not stop moving when it moves to the forward protection limit and the forward protection limit is triggered, the servo driver is controlled to drive the linear motor to stop moving, and the servo drive power input to the servo driver is disconnected.

[0084] If the forward limit fails or the linear motor has too much inertia to stop in time, when the linear motor runs to trigger the forward protection limit, the forward protection limit will shut down the servo drive power input to the servo drive through the drive contactor, and the low-level signal output by the forward protection limit will be input into the servo drive, causing the linear motor to decelerate urgently until it stops moving, and output an alarm signal.

[0085] Furthermore, in a specific embodiment, when the linear motor moves in the reverse direction to trigger the reverse limit, the servo drive is controlled to drive the linear motor to decelerate.

[0086] The reverse motion is the motion towards the reverse limit position. When the linear motor moves in the reverse direction and hits the reverse limit, if the reverse limit works normally and is triggered, the low-level signal output by the reverse limit is input into the servo driver, and the servo driver drives the linear motor to decelerate until it stops, and outputs an alarm signal.

[0087] If the linear motor does not stop moving when it moves to the reverse protection limit and the reverse protection limit is triggered, the servo driver is controlled to drive the linear motor to stop moving, and the servo drive power input to the servo driver is disconnected.

[0088] If the reverse limit fails or the linear motor has too much inertia to stop in time, when the linear motor runs to trigger the reverse protection limit, the reverse protection limit will shut down the servo drive power input to the servo drive through the drive contactor, and the low-level signal output by the reverse protection limit will be input into the servo drive, causing the linear motor to decelerate urgently until it stops moving, and output an alarm signal.

[0089] Furthermore, if the forward and reverse limiters are installed oppositely, that is, the forward limiter is set on the second side of the linear guide rail, and the reverse limiter is set on the first side of the linear guide rail, when the linear motor moves forward to the reverse limiter, the forward limiter is not triggered, so the linear motor continues to move forward until it reaches the forward protection limiter, at which time the forward protection limiter turns off the servo drive power input to the servo drive through the driving contactor, and the low-level signal output by the forward protection limiter is input into the servo drive, causing the linear motor to decelerate urgently until it stops moving, and outputs an alarm signal. Similarly, when the linear motor moves reversely to the forward limiter, the reverse limiter is not triggered, so the linear motor continues to move reversely until it reaches the reverse protection limiter, at which time the reverse protection limiter turns off the servo drive power input to the servo drive through the driving contactor, and the low-level signal output by the reverse protection limiter is input into the servo drive, causing the linear motor to decelerate urgently until it stops moving, and outputs an alarm signal.

[0090] The above-mentioned linear motor protection method performs emergency stop movement through the protection limit when the limit fails, thereby preventing the linear motor from hitting the mechanical hard limit with power, avoiding damage to the motor, and effectively ensuring the safety of the operator.

[0091] The above are only the best embodiments of the present invention and are not intended to limit the scope of the present invention. All equivalent changes or modifications made according to the scope of the patent application of the present invention are covered by the present invention.

Claims

1. A linear motor protection circuit, characterized in that: It includes a servo power supply control circuit and a servo drive circuit connected thereto; wherein the servo drive circuit includes a servo drive, and a linear motor, a positive limit and a positive protection limit respectively connected to the servo drive; The servo power supply control circuit is used to provide servo drive power to the servo driver based on an input external power supply; The servo driver is used to drive the linear motor to move based on the servo drive power supply; When the positive limit is triggered by the linear motor, the signal output by the positive limit controls the servo driver to drive the linear motor to decelerate; When the forward protection limit is triggered by the linear motor, the signal output by the forward protection limit controls the servo driver to drive the linear motor to stop moving; The linear motor protection circuit also includes an external power supply circuit connected to the servo power supply control circuit, and the external power supply circuit provides external power to the servo power supply control circuit; The servo power supply control circuit also includes a servo alarm lamp, and the servo drive circuit also includes a third coil and a first switch; The third coil is connected to the servo driver, and the first switch and the servo alarm light are connected in series and then in parallel to the output end of the external power supply circuit; The servo power supply control circuit includes a servo start button, a servo stop button, a first coil and a first normally open contact; The servo start button, the servo stop button and the first coil are connected in series and then in parallel to the output end of the external power supply circuit; The first normally open contact is respectively connected to the output end of the external power supply circuit and the input end of the servo drive circuit; The servo power supply control circuit also includes an emergency stop button switch, a second coil and a second normally open contact; The servo drive circuit also includes a reverse protection limiter connected to the servo drive; The first normally open contact, the forward protection limit, the reverse protection limit, the emergency stop button switch, and the second coil are connected in series and then in parallel to the output end of the external power supply circuit; The second normally open contact is respectively connected to the output end of the external power supply circuit and the input end of the servo drive circuit.

2. The linear motor protection circuit according to claim 1, characterized in that: The servo drive circuit also includes a reverse limiter connected to the servo drive; When the reverse limit is triggered by the linear motor, the signal output by the reverse limit controls the servo driver to drive the linear motor to decelerate; When the reverse protection limit is triggered by the linear motor, the signal output by the reverse protection limit controls the servo driver to drive the linear motor to stop moving.

3. The linear motor protection circuit according to claim 1, characterized in that: The external power supply circuit includes: a power line, a circuit breaker, a filter and a surge protector for providing external power; The first end of the circuit breaker is connected to the power line, the second end of the circuit breaker is connected to the first end of the filter, and the second end of the filter is connected to the servo power supply control circuit; The surge protector is connected to the first end of the filter and the second end of the circuit breaker respectively.

4. A linear motor protection system, characterized in that: It comprises a linear guide rail and a linear motor protection circuit as claimed in any one of claims 1 to 3, wherein the linear motor is arranged on the linear guide rail; The servo driver drives the linear motor to move along the linear guide rail; The positive limit is arranged on the first side of the linear guide rail; when the linear motor moves to trigger the positive limit, the signal output by the positive limit is used to control the servo driver to drive the linear motor to decelerate; The forward protection limit is arranged beside the forward limit; wherein, when the linear motor moves out of the forward limit and moves to trigger the forward protection limit, the signal output by the forward protection limit is used to control the servo drive to drive the linear motor to stop moving.

5. The linear motor protection system according to claim 4, characterized in that: The linear motor protection system also includes a positive hard limit and a reverse hard limit arranged on the linear guide rail; The positive hard limit is arranged at the first end of the linear guide rail; the positive protection limit is arranged between the positive hard limit and the positive limit; The reverse hard limit is arranged at the second end of the linear guide rail; The reverse limit is arranged on the second side of the linear guide rail; when the linear motor moves to trigger the reverse limit, the signal output by the reverse limit is used to control the servo driver to drive the linear motor to decelerate; The reverse protection limit is set between the reverse hard limit and the reverse limit; wherein, when the linear motor moves to trigger the reverse protection limit, the signal output by the reverse protection limit is used to control the servo drive to drive the linear motor to stop moving.

6. A linear motor protection method, characterized in that: Applied to the linear motor protection circuit as described in any one of claims 1 to 3, or the linear motor protection system as described in any one of claims 4 to 5, the method comprises: When the linear motor moves forward to trigger the positive limit, the servo driver is controlled to drive the linear motor to decelerate, and the positive movement is moving toward the position of the positive limit; If the linear motor does not stop moving when it moves to the forward protection limit and triggers the forward protection limit, the servo driver is controlled to drive the linear motor to stop moving, and the servo drive power input to the servo driver is disconnected.

7. The method according to claim 6, characterized in that The method further comprises: When the linear motor moves in the reverse direction to trigger the reverse limit, the servo driver is controlled to drive the linear motor to decelerate, and the reverse movement is movement toward the position of the reverse limit; If the linear motor does not stop moving when it moves to the reverse protection limit and triggers the reverse protection limit, the servo driver is controlled to drive the linear motor to stop moving, and the servo drive power input to the servo driver is disconnected.

8. The method according to claim 7, characterized in that The method further comprises: If the positive limit is set on the second side of the linear guide rail, and the reverse limit is set on the first side of the linear guide rail; When the linear motor moves forward to trigger the forward protection limit, the servo driver is controlled to drive the linear motor to stop moving, and the servo drive power input to the servo driver is disconnected; When the linear motor moves in the reverse direction to trigger the reverse protection limit, the servo driver is controlled to drive the linear motor to stop moving, and the servo drive power input to the servo driver is disconnected.

Images