Relay protection device, construction machine, relay protection control method and device

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of electrical control of engineering machinery, and in particular, to a relay protective apparatus, an engineering machine, a relay protection control method and apparatus, and a non-transitory computer-readable storage medium.BACKGROUND

[0002] With the development of technologies such as intelligent and integrated manufacturing, electrical control technology has been developed rapidly. As an important subsystem of an engineering machine, the electrical system plays a vital role in the performance of the engineering machine.

[0003] Taking an excavator as an example, three basic load circuits of its electrical system, namely its power supply circuit, preheating circuit and startup circuit, have the characteristics of large working current and high load impact. Relay protective apparatus is used for relay protection of these circuits to reduce the occurrence of faults and abnormal conditions.

[0004] In DE10101353A1, the method involves a controller outputting a signal with which the switch element is operated and outputting a trigger signal repeatedly at defined times with which the switch element can be brought into a defined switch setting. A circuit for operating a bistable switch element has a controller whose signal output(s) is connected to at least one activation input of the switch element. Independent claims are also included for the following: a circuit for operating at least one bistable switch element.

[0005] In US2019080868A1, an improved bi-stable relay operable with a relay control circuit includes a boost converter and an energy storage device, which is used to switch the bi-stable relay. In some embodiments, the bi-stable relay includes a solenoid wound with multiple coil windings. A conductive plate (e.g., a bus bar) may be coupled to a plunger of the solenoid, and is provided with contacts on each end of the conductive plate. The conductive plate is configured to electrically engage and disengage the solenoid upon respective application of power to the solenoid. The control circuit causes the solenoid to remain in an open position when selectively energized by a pulse for moving and retaining the conductive plate of the plunger against the solenoid for allowing wide operating voltage and reduced operating power.

[0006] In EP2840584A2, a normal relay emulator is described. The normal relay emulator may include a trigger circuit configured to detect a condition on a first power rail, the first power rail having a first voltage supply level. A boost converter electrically coupled to the first power rail and configured to boost the first voltage supply level to a second, higher, voltage supply level is provided. A bi-stable relay having a first terminal and a second terminal and an actuator electrically coupled to the boost converter and communicatively coupled to the trigger circuit is also provided. The actuator may be configured to energize the bi-stable relay using the second voltage supply level such that electrical contact between the first terminal and the second terminal changes between a first state and a second state based on the trigger circuit detecting the condition.

[0007] In CN104941200A, the invention discloses a control system of a safety amusement excavator and relates to a control system. The control system is used for controlling work of the safety amusement excavator. The safety amusement excavator comprises a motor, a hydraulic pump, a coin inserting device, a hydraulic oil tank, a large arm oil cylinder, a small arm oil cylinder, an excavator bucket oil cylinder and a rotary oil cylinder, the control system comprises an electric control device and a hydraulic control device, the electric control device comprises a controller, an overload protection switch, a relay, a sudden stop switch and a safety sensor, the controller is connected with the motor through a circuit and can control startup or stop of the motor through a control signal, the hydraulic control device comprises a manually-operated hydraulic quadruple valve and four throttling valves, and the hydraulic pump controls works of the large arm oil cylinder, the small arm oil cylinder, the excavator bucket oil cylinder and the rotary oil cylinder respectively through the manually-operated hydraulic quadruple valve. The amusement excavator is controlled by adopting the control system, the amusement excavator can be safely and reliably controlled to work safely, and an operator operating the amusement excavator can obtain feelings more similar to the feelings of operating a real excavator.

[0008] In CN207009367U, the utility model provides a VSP5 feeder terminal's control export return circuit, including mains side power supply loop, combined floodgate output circuit, load side power supply loop, operation export return circuit, the relay all adopts bistable relay (magnetic latching relay) among mains side power supply loop, combined floodgate output circuit, the load side power supply loop, and this relay has two coils, a set coil, a reset line circle, it is closed to issue order set contact as CPU, when giving voltage pulse of set coil, and the normally open contact actuation, issuing the order as CPU, to reset the contact closed, during for voltage pulse on the reset line circle, and the normally open contact disconnection of actuation.SUMMARY

[0009] The present invention provides a relay protective apparatus, an engineering machine, a relay protection control method and apparatus, and a non-transitory computer-readable storage medium, so as to improve the reliability of the relay protective apparatus, prolong its service life, and further improve the reliability of the electrical system of the engineering machine.

[0010] According to the present invention, a relay protective apparatus is provided, comprising: a power input connection point which is a terminal of the relay protective apparatus to connect with an external system power supply; a relay protection circuit, comprising a bistable relay and an output connection point, the bistable relay comprising a contact, a pull-in coil and a release coil, an input terminal of the contact, an input terminal of the pull-in coil and an input terminal of the release coil being connected to the power input connection point, an output terminal of the contact being connected to the output connection point, and the output connection point (J1) is a terminal of the relay protective apparatus to connect with an external power circuit; a central controller, comprising a first port connected to the output connection point, a second port connected to the output terminal of the pull-in coil, and a third port connected to the output terminal of the release coil, wherein under a control of the central controller, the pull-in coil and the release coil are powered alternately to make the contact be opened and closed frequently, in response to a voltage of the output connection point being less than a first threshold and not less than a second threshold, wherein the first threshold is less than a standard operating voltage of the bistable relay, and the second threshold is a minimum allowable operating voltage of the bistable relay.

[0011] In some embodiments, the central controller triggers the pull-in coil to close the contact if the voltage of the output connection point is not less than the first threshold or the number of times the contact oscillating continuously is not less than a preset number of times;. the central controller is used for acquiring the voltage of the output connection point at every preset interval.

[0012] In some embodiments, the relay protective apparatus further comprises: a fault indicator; wherein the central controller further comprises a fourth port connected to the fault indicator, and the central controller also controls the fault indicator to send a first fault indication information when the voltage of the output connection point is zero; and, when the voltage of the output connection point is greater than zero and less than the second threshold, controlling the fault indicator to a send second fault indication information; and the fault indicator comprises an indicator light or a buzzer.

[0013] In some embodiments, the relay protection circuit further comprises a first storage capacitor, wherein the input terminal of the contact, the input terminal of the pull-in coil and the input terminal of the release coil are further connected to an output terminal of the first storage capacitor; and the relay protection circuit further comprises a fuse-link connected in series with the bistable relay, wherein an input terminal of the fuse-link is connected to the output terminal of the contact, and an output terminal of the fuse-link is connected to the output connection point.

[0014] In some embodiments, the relay protective apparatus further comprises: a voltage regulator and a second storage capacitor, wherein an input terminal of the voltage regulator is used to connect to a power-on output terminal of a key switch; the central controller further comprises a power port, which is connected to an output terminal of the voltage regulator and an output terminal of the second storage capacitor; the voltage regulator is a low dropout linear voltage regulator (LDO).

[0015] In some embodiments, three relay protection circuits are provided, namely a power circuit relay protection circuit, a startup circuit relay protection circuit, and a preheating circuit relay protection circuit; the central controller further comprises a fifth port for connecting to a startup output terminal of the key switch, and a sixth port for communicating with a vehicle-mounted controller, wherein the central controller controls the power circuit relay protection circuit to work when receiving a power-on signal from the power-on output terminal of the key switch; controlling the startup circuit relay protection circuit to work when receiving a startup signal from the startup output terminal of the key switch in the power-on state; controlling the preheating circuit relay protection circuit to work when receiving a start-to-preheat signal from the vehicle-mounted controller in the power-on state.

[0016] In some embodiments, the sixth port of the central controller connects with the vehicle-mounted controller of the engineering machine through a controller area network (CAN) bus.

[0017] According to the present invention, an engineering machine is provided, comprising the relay protective apparatus described in any of the foregoing technical solutions.

[0018] In some embodiments, the engineering machine comprises an excavator.

[0019] Still according to the present invention, a relay protection control method is provided, which is applied to the aforementioned relay protective apparatus, the relay protection control method comprising: acquiring a voltage of an output connection point of a relay protection circuit; in response to the voltage of the output connection point of the relay protection circuit being less than a first threshold and not less than a second threshold, controlling a pull-in coil and a release coil of the relay protection circuit to be powered alternately, so that a contact of the relay protection circuit is opened and closed frequently; wherein the first threshold is less than a standard working voltage of a bistable relay, and the second threshold is a minimum allowable working voltage of the bistable relay.

[0020] In some embodiments, the relay protection control method further comprises: if the voltage of the output connection point is not less than the first threshold or the number of times the contact oscillating continuously is not less than a preset number of times, triggering the pull-in coil to close the contact.

[0021] In some embodiments, acquiring a voltage of an output connection point of a relay protection circuit comprises: acquiring the voltage of the output connection point of the relay protection circuit at every preset interval.

[0022] According to the present invention, a relay protection control apparatus as set forth in claim 13 is provided.

[0023] According the present invention, a relay protection control apparatus is provided, comprising: memory; and a processor coupled to the memory, the processor being configured to execute the relay protection control method described in any one of the preceding technical solutions based on instructions stored in the memory.

[0024] According to the present invention, a non-transitory computer-readable storage medium is provided, on which a computer program is stored, which when executed by a processor implements the relay protection control method described in any of the foregoing technical solutions.

[0025] Other features and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated in and constitute a portion of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0027] The present disclosure will be more clearly understood from the following detailed description with reference to the accompanying drawings, in which: FIG. 1 is a schematic diagram of a relay protective apparatus of an excavator in the related art; FIG. 2 is a schematic diagram of a relay protective apparatus according to the present invention; FIG. 3 is a flowchart of a relay protection control method according to the present invention; FIG. 4 is a block diagram of a relay protection control apparatus according to the present invention; FIG. 5 is a block diagram of a relay protection control apparatus according to the present invention; FIG. 6 is a block diagram of a computer system of the present invention.

[0028] It should be understood that the dimensions of the various parts shown in the drawings are not drawn to the actual scale. In addition, the same or similar reference signs are used to denote the same or similar components.DETAILED DESCRIPTION

[0029] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The following description of the exemplary embodiments is in fact merely illustrative and is in no way intended as a limitation to the present disclosure, its application or use. The present disclosure may be implemented in many different forms, not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Notice that, unless specifically stated otherwise, relative arrangement of components and steps set forth in these embodiments are to be construed as merely illustrative, and not as a limitation.

[0030] Unless otherwise defined, all terms (comprising technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which exemplary embodiments in accordance with principles of inventive concepts belong. It will also be understood that terms defined in such general-purpose dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art, and not to be interpreted in an idealized or overly formal sense, unless explicitly defined herein.

[0031] Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, these techniques, methods, and apparatuses should be considered as part of the specification.

[0032] As shown in FIG. 1, a relay protective apparatus 8' applied to an excavator in the related art comprises a power circuit relay protection module M1', a startup circuit relay protection module M2', and a preheating circuit relay protection module M3' arranged in parallel. Each relay protection module comprises a fuse-link (such as fuse-links F1', F2', F3'), a relay (such as relays K1', K2', K3') and an output connection point (such as output connection points J1', J2', J3'). The relay protective apparatus 8' is applied in the electrical system of the excavator. A system power supply 10', a main power switch S1', a fuse-link, a relay's contact, and an output connection point are connected in sequence.

[0033] In the process of realizing the embodiments of the present disclosure, the inventor noticed that in the above mentioned related art, when a relay is in its normal working state, its coil will always be powered, which may generate a relatively large amount of heat. In addition, the contact will always be in a pull-in state because the coil is powered, and its lifespan will be shortened accordingly; moreover, since the three relay protection modules are arranged inside an electrical box, it is not easy to detect relay failure, leading to poor repairability. These factors seriously affect the reliability of the relay protective apparatus, which in turn affects the reliability of the excavator's electrical system. How to improve the reliability of relay protective apparatus and prolong its service life is a technical problem that needs to be solved urgently.

[0034] Embodiments of the present invention provide a relay protective apparatus, an engineering machine, a relay protection control method and apparatus, and a non-transitory computer-readable storage medium, so as to improve the reliability of the relay protective apparatus, prolong its service life, and further improve the reliability of the electrical system of the engineering machine.

[0035] The invention provides a relay protective apparatus, which can be applied to various types of engineering machines that require relay protection, and can bring about similar beneficial effects. The specific type of the engineering machine is not limited, for example, it can be an excavator, a road roller, a crane, and the like. The following description will be given with an example in which a relay protective apparatus is applied to an excavator.

[0036] As shown in FIG. 2, the present invention provides a relay protective apparatus 8, which comprises a power input connection point J4, at least one relay protection circuit, and a central controller 100. The relay protection circuit is, for example, a power circuit relay protection circuit M1, a startup circuit relay protection circuit M2, or a preheating circuit relay protection circuit M3 shown in the figure. Wherein the power input connection point J4 can be understood as a terminal used by the relay protective apparatus 8 to connect with an external system power supply.

[0037] The power circuit relay protection circuit M1 comprises a bistable relay K1 and an output connection point J1. The bistable relay K1 comprises a contact H1, a pull-in coil Q11 and a release coil Q12. An input terminal of the contact H1 (the input terminal of each device is represented by "1", and the output terminal is represented by "2" in FIG. 2), an input terminal of the pull-in coil Q11 and an input terminal of the release coil Q12 are connected to the power input connection point J4. An output terminal of the contact H1 is connected to an output connection point J1. The output connection point J1 is a terminal used by the relay protective apparatus 8 to connect with an external power circuit.

[0038] Similarly, the startup circuit relay protection circuit M2 comprises a bistable relay K2 and an output connection point J2. The bistable relay K2 comprises a contact H2, a pull-in coil Q21 and a release coil Q22. An input terminal of the contact H2, an input terminal of the pull-in coil Q21 and an input terminal of the release coil Q22 are connected to the power input connection point J4. An output terminal of the contact H2 is connected to an output connection point J2. The output connection point J2 is a terminal used by the relay protective apparatus 8 to connect with an external startup circuit.

[0039] Similarly, the preheating circuit relay protection circuit M3 comprises a bistable relay K3 and an output connection point J3. The bistable relay K3 comprises a contact H3, a pull-in coil Q31 and a release coil Q32. An input terminal of the contact H3, an input terminal of the pull-in coil Q31 and an input terminal of the release coil Q32 are connected to the power input connection point J4. An output terminal of the contact H3 is connected to an output connection point J3. The output connection point J3 is a terminal used by the relay protective apparatus 8 to connect with an external preheating circuit.

[0040] The central controller 100 comprises first ports D11, D21, D31, second ports D12, D22, D32, and third ports D13, D23, D33, wherein the first port D11 is connected to the output connection point J1, and the first port D21 is connected to the output connection point J2, the first port D31 is connected to the output connection point J3, the second port D12 is connected to the output terminal of the pull-in coil Q11, the second port D22 is connected to the output terminal of the pull-in coil Q21, the second port D32 is connected to the output terminal of the pull-in coil Q31, the third port D13 is connected to the output terminal of the release coil Q12, the third port D23 is connected to the output terminal of the release coil Q22, and the third port D33 is connected to the output terminal of the release coil Q32.

[0041] The central controller 100 is used to control the pull-in coil Q11 and the release coil Q12 to be powered alternately when the voltage of the output connection point J1 is less than a first threshold and not less than a second threshold, so that the contact H1 oscillates, that is, to frequently open and close the contact H1; control the pull-in coil Q21 and the release coil Q22 to be powered alternately when the voltage of the output connection point J2 is less than the first threshold and not less than the second threshold, so that the contact H2 oscillates, that is, to frequently open and close the contact H2; and control the pull-in coil Q31 and the release coil Q32 to be powered alternately when the voltage of the output connection point J3 is less than the first threshold and not less than the second threshold, so that the contact H3 oscillates, that is, to frequently open and close the contact H3; wherein the first threshold is less than a standard working voltage of a bistable relay, and the second threshold is a minimum allowable working voltage of the bistable relay.

[0042] The standard working voltage of the bistable relay is an ideal working voltage of the bistable relay. When the voltage of the output connection point is less than the first threshold but not less than the second threshold, the contact performance of the contact is reduced, but it will not cause the bistable relay to not work properly. The first threshold can be determined through multiple tests in combination with the structure and performance of the bistable relay, and is a preset value.

[0043] In the electrical system of the excavator, in addition to the relay protective apparatus 8 described above, it usually also comprises a system power supply 10, a main power switch S1, a key switch S2, a vehicle-mounted controller 20, and the like. The key switch S2 comprises a power input terminal B, a power-on output terminal BR and a startup output terminal C. The power input terminal B of the key switch S2 is connected to the main power switch S1, and a fuse F2 can be disposed on the line between the main power switch S1 and the power input terminal B to protect the line from overcurrent and short circuit. In addition to the first ports D11, D21, D31, the second ports D12, D22, D32 and the third ports D13, D23, D33, the central controller 100 further comprises a power port D7, a fourth port D41 connected to a fault indicator A1, a fourth port D42 connected to a fault indicator A2, a fourth port D43 connected to a fault indicator A3, a fifth port D5 connected to the startup output terminal C of the key switch S2, and sixth ports D61 and D62 connected to the vehicle-mounted controller 20.

[0044] The power circuit, the startup circuit and the preheating circuit are three basic load circuits of the excavator's electrical system. In this embodiment of the present disclosure, three relay protection circuits are respectively provided for these three basic load circuits in the relay protective apparatus 8, that is, the above mentioned power circuit relay protection circuit M1, startup circuit relay protection circuit M2, and preheating circuit relay protection circuit M3. Each relay protection circuit is connected to a corresponding load circuit through an output connection point (other parts of the load circuit are omitted and not shown in the figure).

[0045] As shown in FIG. 2, the relay protective apparatus 8 further comprises a voltage regulator 9, and an input terminal of the voltage regulator 9 is connected to the power-on output terminal BR of the key switch S2. The power port D7 of the central controller 100 is connected to an output terminal of the voltage regulator 9. The voltage regulator 9 is, for example, a low dropout linear voltage regulator (LDO), whose input terminal supports a wide voltage range, and can support a maximum voltage input of 42V, and its output terminal outputs a steady-state DC voltage, for example, a 5V DC voltage, so as to provide a stable working voltage for the central controller 100.

[0046] The relay protection circuit is a bistable relay with two stable states. As shown in FIG. 2, taking the bistable relay K1 as an example, when a grounding voltage is output to the pull-in coil Q11 at a first timing, the contact H1 changes from a normally open state to a normally closed state, and after the pull-in coil Q11 is powered off, the contact H1 can still maintain the normally closed state due to the magnetism of a polarized soft magnet; when a grounding voltage is output to the release coil Q12 at a second timing, the contact H1 changes from a normally closed state to a normally open state, and after the release coil Q12 is powered off, the contact H1 can still maintain the normally open state due to the magnetism of a polarized soft magnet. The bistable relay does not require its coil to be powered all the time to maintain the pull-in state of the contact. Therefore, it has the advantages of energy saving and low heat generation of the coil.

[0047] The central controller 100 is used to control the power circuit relay protection circuit M1 to work when receiving a power-on signal from the power-on output terminal BR of the key switch S2; control the startup circuit relay protection circuit M2 to work when receiving a startup signal from the startup output terminal C of the key switch S2 in the power-on state; and control the preheating circuit relay protection circuit M3 to work when receiving a start-to-preheat signal from the vehicle-mounted controller 20 in the power-on state.

[0048] For example, after the main power switch S1 is closed, when an operator turns the key switch S2 to the power-on output terminal BR, the power-on output terminal BR is powered, and power is supplied to the power port D7 of the central controller 100 through the voltage regulator 9. After the central controller 100 receives a power-on signal, it outputs a grounding voltage to the pull-in coil Q11 of the bistable relay K1 in the power circuit relay protection circuit M1, so that the contact H1 changes from a normally open state to a normally closed state, so as to turn on the power circuit of the excavator. While the power circuit is in the turn-on state, when it is detected that the voltage of the output connection point J1 is less than the first threshold and not less than the second threshold, it can be determined that the contact performance of the contact H1 in the power circuit relay protection circuit M1 is reduced. In this case, the pull-in coil Q11 and the release coil Q12 are controlled to be alternately powered through, for example, outputting a grounding voltage to the pull-in coil Q11 and the release coil Q12 alternately, so that the contact H1 oscillates and is rapped repeatedly, which can effectively reduce the accumulation of foreign objects on the contact H1, thereby improving the electrical contact performance of the contact H1.

[0049] For example, after the power circuit is turned on, when the operator turns the key switch S2 to the startup output terminal C, the startup output terminal C outputs a high-level startup signal to the central controller 100. After receiving the startup signal from the startup output terminal C, the central controller 100 outputs a grounding voltage to the pull-in coil Q21 of the bistable relay K2 in the startup circuit relay protection circuit M2, so that the contact H2 changes from the normally open state to the normally closed state, so as to turn on the startup circuit of the excavator. While the startup circuit is in the turn-on state, when the voltage of the output connection point J2 is less than the first threshold and not less than the second threshold, it can be determined that the contact performance of the contact H2 in the startup circuit relay protection circuit M2 is reduced. In this case, the pull-in coil Q21 and the release coil Q22 are controlled to be alternately powered through, for example, outputting a grounding voltage to the pull-in coil Q21 and the release coil Q22 alternately, so that the contact H2 oscillates and is rapped repeatedly, which can effectively reduce the accumulation of foreign objects on the contact H2, thereby improving the electrical contact performance of the contact H2.

[0050] For example, after the power circuit is turned on, when the operator operates a Preheat button on the excavator's console, the vehicle-mounted controller 20 outputs a start-to-preheat signal to the central controller 100. After receiving the start-to-preheat signal from the vehicle-mounted controller 20, the central controller 100 outputs a grounding voltage to the pull-in coil Q31 of the bistable relay K3 in the preheating circuit relay protection circuit M3, so that the contact H3 changes from the normally open state to the normally closed state, so as to turn on the preheating circuit of the excavator. While the preheating circuit is in the turn-on state, when the voltage of the output connection point J3 is less than the first threshold and not less than the second threshold, it can be determined that the contact performance of the contact H3 in the (preheating circuit) relay protection circuit M3 is reduced. In this case, the pull-in coil Q31 and the release coil Q32 are controlled to be alternately powered through, for example, outputting a grounding voltage to the pull-in coil Q31 and the release coil Q32 alternately, so that the contact H3 oscillates and is rapped repeatedly, which can effectively reduce the accumulation of foreign objects on the contact H3, thereby improving the electrical contact performance of the contact H3.

[0051] In some embodiments of the present disclosure, the sixth ports D61 and D62 of the central controller 100 are used for connecting with the vehicle-mounted controller 20 through a controller area network (CAN) bus. In some embodiments, the sixth port D61 is used for reporting information to the vehicle-mounted controller 20, and the sixth port D62 is used for receiving information sent by the vehicle-mounted controller 20, thereby realizing mutual communication. The specific number of the sixth ports is not limited and can be designed according to practical needs.

[0052] In some embodiments of the present disclosure, the contact structure in the relay protection circuit can be made of red copper stripes, which has good electrical conductivity, thermal conductivity, weldability and corrosion resistance.

[0053] It can be understood that, if the relay protective apparatus provided by the embodiments of the present disclosure is applied in other engineering machines, the number of relay protection circuits can be adjusted as required, and the specific structure of the electrical system may also be different.

[0054] In the related art, when a relay of the relay protection circuit is in its normal working state, its coil is always powered, which may generate a relatively large amount of heat. In addition, the contact is always in a pull-in state because the coil is powered. The long-term large current flowing through the contact makes the contact easy to be oxidized, and it is also easy to accumulate foreign objects on the contact. Over time, it will not only affect the reliability of the contact performance of the contact, but also shorten its service life.

[0055] In accordance with the invention, a bistable relay is adopted in the relay protection circuit, which does not require the coil to be powered all the time to maintain the pull-in state of the contact, having the advantages of energy saving and low heat generation of the coil, capable of effectively improving the oxidation phenomenon of the contact and prolonging the service life of the contact. On the other hand, in the technical solution of the invention, when the voltage of the output connection point (of a contact) is less than the first threshold and not less than the second threshold, it can be determined that the contact's performance is reduced. In this case, the pull-in coil and the release coil are controlled to be alternately powered through, for example, outputting a grounding voltage to the pull-in coil and the release coil alternately, so that the contact oscillates and is rapped repeatedly, which can effectively reduce the accumulation of foreign objects on the contact, thereby improving the contact's electrical contact reliability. Therefore, by adopting the technical solution of the embodiments of the present disclosure, the reliability of the relay protective apparatus can be effectively improved, the service life thereof can be prolonged, and the reliability of the electrical system of the engineering machine can be improved.

[0056] In addition, in the embodiment of the present disclosure, a platform-based and integrated design is adopted for the relay protective apparatus. The various relay protection circuits, the voltage regulator and other components are integrated with the central controller, resulting in a compact structure, that is, the device has a compact appearance and volume, and its cost is greatly reduced.

[0057] The central controller 100 is further used for triggering the pull-in coil to close the contact if the voltage of each of above output connection points is not less than the first threshold or the number of times the contact oscillating continuously is not less than a preset number of times. As described above, through causing the contact to oscillate and rapping the contact repeatedly, the electrical contact performance of the contact can be improved and the contact resistance can be reduced. After certain conditions are met, the pull-in coil can be triggered to close the contact and restore the normal operation of the bistable relay. The preset number of times can be determined in combination with the performance of the bistable relay and experience, for example, the preset number of times may be set to 5.

[0058] In some embodiments of the present disclosure, the central controller 100 is used for acquiring the voltage of the output connection point at every preset interval, i.e., according to a preset maintenance cycle.

[0059] Wherein the preset interval can be determined through multiple tests in combination with the structure, working performance, rated service life, etc. of the bistable relay. For example, in some embodiments, the acquisition of the voltage of the output connection point and the self-check and improvement maintenance of contact performance are carried out every 500 hours. With the solution of this embodiment, a number of times of the contact can be closed normally can be guaranteed, which is beneficial to prolong the service life of the contact and ensure that the bistable relay is in its normal working state most of the time.

[0060] Referring to FIG. 2, the relay protective apparatus 8 may further comprise a fault indicator A1 provided for the power circuit relay protection circuit M1, and a fault indicator A2 provided for the startup circuit relay protection circuit M2, and a fault indicator A3 provided for the preheating circuit relay protection circuit M3. The specific type of the fault indicator is not limited, for example, it may be an indicator light or a buzzer. The central controller 100 is connected to the fault indicator A1 through a fourth port D41, is connected to the fault indicator A2 through a fourth port D42, and is connected to the fault indicator A3 through a fourth port D43. The central controller 100 is further used to control the fault indicator A1 to send first fault indication information when the voltage of the output connection point J1 is zero, and to control the fault indicator A1 to send second fault indication information when the voltage of the output connection point J1 is greater than zero and less than the second threshold; control the fault indicator A2 to send first fault indication information when the voltage of the output connection point J2 is zero, and to control the fault indicator A2 to send second fault indication information when the voltage of the output connection point J2 is greater than zero and less than the second threshold; and control the fault indicator A3 to send first fault indication information when the voltage of the output connection point J3 is zero, and to control the fault indicator A3 to send second fault indication information when the voltage of the output connection point J3 is greater than zero and less than the second threshold.

[0061] Taking the power circuit relay protection circuit M1 as an example, when the voltage of the output connection point J1 is zero, it can be determined that the load circuit in which the power circuit relay protection circuit M1 is located is open, and the fault indicator A1 sends first fault indication information, for example, an indicator light is lighted or a buzzer keeps long beeps, so that the operator can be notified of the fault in time. When the voltage of the output connection point J1 is greater than zero and less than the second threshold, it can be determined that the contact resistance of the contact H1 is too large, which has seriously affected the normal operation and relay protection of the load circuit. In this case, the fault indicator A1 sends second fault indication information, for example, an indication light flashes or a buzzer keeps short beeps, so that the operator can be notified of the fault in time. With the technical solution of this embodiment, automatic fault diagnosis and prompt can be realized, so as to improve the intelligence level of the relay protective apparatus.

[0062] In addition, in some embodiments of the present disclosure, when the central controller 100 determines that a certain load circuit has an open-circuit fault or an excessive contact resistance fault, it can also report a corresponding fault code to the vehicle-mounted controller 20 through the sixth port D61. The vehicle-mounted controller 20 can analyze the fault and perform self-diagnosis, and then output a diagnosis result to an output device, such as a display screen and an indicator light.

[0063] As shown in FIG. 2, the power circuit relay protection circuit M1 may further comprise a first storage capacitor C11 and a fuse-link F11, wherein the input terminal of the contact H1, the input terminal of the pull-in coil Q11, and the input terminal of the release coil Q12 are also connected to an output terminal of the first storage capacitor C11; the fuse-link F11 is connected in series with the bistable relay K1, with an input terminal of the fuse-link F11 connected to the output terminal of the contact H1, and an output terminal of the fuse-link F11 connected to the output connection point J1. The startup circuit relay protection circuit M2 may further comprise a first storage capacitor C12 and a fuse-link F12, wherein the input terminal of the contact H2, the input terminal of the pull-in coil Q21, and the input terminal of the release coil Q22 are also connected to an output terminal of the first storage capacitor C12; the fuse-link F12 is connected in series with the bistable relay K2, with an input terminal of the fuse-link F12 connected to the output terminal of the contact H2, and an output terminal of the fuse-link F12 connected to the output connection point J2. The preheating circuit relay protection circuit M3 may further comprise a first storage capacitor C13 and a fuse-link F13, wherein the input terminal of the contact H3, the input terminal of the pull-in coil Q31, and the input terminal of the release coil Q32 are also connected to an output terminal of the first storage capacitor C13; the fuse-link F13 is connected in series with the bistable relay K3, with an input terminal of the fuse-link F13 connected to the output terminal of the contact H3, and an output terminal of the fuse-link F13 connected to the output connection point J3.

[0064] As a protection device, the fuse-link can perform short-circuit and over-current protection for the load circuit to prevent the device from being burned. The first storage capacitor can supply power to the release coil when the power supply to the bistable relay is abnormally cut off, for example, when the main power switch of the system is abnormally switched off, thereby ensuring that the release coil can be released normally.

[0065] Referring to FIG. 2, in some embodiments of the present disclosure, the relay protective apparatus 8 further comprises a second storage capacitor C2, wherein the power port D7 of the central controller 100 is connected to both the output terminal of the voltage regulator 9 and the output terminal of the second storage capacitor C2. The second storage capacitor C2 can continue to supply power to the central controller 100 after the power-on output terminal BR of the key switch is de-powered. On the one hand, it can ensure that the release coil of the bistable relay can be released normally, preventing the system from generating static power consumption due to leakage current. On the other hand, it can realize the vehicle controller 20's delay control on the central controller 100.

[0066] To sum up, the relay protective apparatus of the present invention not only has better reliability of relay protection for the load circuit, but also has a longer service life and a higher degree of integration and intelligence, which can effectively improve the reliability and intelligence of the engineering machine's electrical system.

[0067] The present invention further provides an engineering machine, comprising the relay protective apparatus described in any of the foregoing embodiments. The specific type of the engineering machine comprises, but is not limited to, an excavator, for which the reliability and intelligence of its electrical system can be effectively improved.

[0068] As shown in FIG. 3, the present invention further provides a relay protection control method applied to the aforementioned relay protective apparatus, the method comprising steps S101 to S102: Step S101: acquiring a voltage of an output connection point of a relay protection circuit; Step S102: if the voltage of the output connection point of the relay protection circuit is less than a first threshold and not less than a second threshold, controlling a pull-in coil and a release coil of the relay protection circuit to be powered alternately, so that a contact of the relay protection circuit oscillates; wherein the first threshold is less than a standard working voltage of a bistable relay, and the second threshold is a minimum allowable working voltage of the bistable relay.

[0069] In some embodiments of the present disclosure, the relay protection control method further comprises the following step: if the voltage of the output connection point is not less than the first threshold or the number of times the contact oscillating continuously is not less than a preset number of times, triggering the pull-in coil to close the contact.

[0070] In some embodiments of the present disclosure, acquiring a voltage of an output connection point of a relay protection circuit comprises: acquiring the voltage of the output connection point of the relay protection circuit at every preset interval.

[0071] In some embodiments of the present disclosure, the relay protection control method further comprises the following step: if the voltage of the output connection point of the relay protection circuit is zero, sending first fault indication information; if the voltage of the output connection point of the relay protection circuit is greater than zero and less than the second threshold, sending second fault indication information.

[0072] In the technical solution of the embodiments of the present invention when the voltage of the output connection point (of a contact) is less than the first threshold and not less than the second threshold, it can be determined that the contact's performance is reduced. In this case, the pull-in coil and the release coil are controlled to be alternately powered through, for example, outputting a grounding voltage to the pull-in coil and the release coil alternately, so that the contact oscillates and is rapped repeatedly, which can effectively reduce the accumulation of foreign objects on the contact, thereby improving the contact's electrical contact reliability. Through causing the contact to oscillate and rapping the contact repeatedly, the electrical contact performance of the contact can be improved, and the contact resistance can be reduced. After certain conditions are met, the pull-in coil can be triggered to close the contact and restore the normal operation of the bistable relay. When a load circuit has an open circuit fault or an excessive contact resistance fault, first fault indication information or second fault information issued can prompt the operator to intervene in time, which can realize automatic fault diagnosis and prompt, thereby improving the degree of intelligence. Therefore, through adopting the relay protection control method of the embodiment of the present disclosure, the reliability of the relay protective apparatus can be effectively improved, the service life thereof can be prolonged, and the reliability of the electrical system of the engineering machine can be improved.

[0073] As shown in FIG. 4, the present invention further provides a relay protection control apparatus, comprising: an acquisition unit 41 for acquiring a voltage of an output connection point of a relay protection circuit; a control unit 42 for, if the voltage of the output connection point of the relay protection circuit is less than a first threshold and not less than a second threshold, controlling a pull-in coil and a release coil of the relay protection circuit to be powered alternately, so that a contact of the relay protection circuit oscillates; wherein the first threshold is less than a standard working voltage of a bistable relay, and the second threshold is a minimum allowable working voltage of the bistable relay.

[0074] As shown in FIG. 5, the present invention further provides a relay protection control apparatus, comprising: a memory 51 and a processor 52 coupled to the memory 51, the processor 52 being configured to execute the relay protection control method described in any one of the foregoing embodiments based on instructions stored in the memory 51.

[0075] It should be understood that each step in the foregoing relay protection control method may be implemented by a processor, and may be implemented in any of software, hardware, firmware, or a combination thereof.

[0076] In addition to the relay protection control method and apparatus described above, the present invention provides a computer program product implemented on one or more non-volatile storage media containing computer program instructions. Thus, the present invention further provides a computer-readable storage medium, on which a computer program is stored, which when executed by a processor implements the relay protection control method described in any of the foregoing technical solutions.

[0077] FIG. 6 shows a structural diagram of a computer system according to the present invention. As shown in FIG. 6, the computer system may be in the form of a general-purpose computing device, and the computer system may be used to implement the relay protection control method of the foregoing embodiments. The computer system comprises a memory 61, a processor 62, and a bus 60 connecting different system components.

[0078] The memory 61 may comprise, for example, a system memory, a non-volatile storage medium, and the like. The system memory stores, for example, an operating system, application programs, a boot loader (Boot Loader), and other programs. The system memory may comprise a volatile storage medium such as random access memory (RAM) and / or cache memory. The non-volatile storage medium stores, for example, instructions for executing a corresponding embodiment of the relay protection control method described above. The non-volatile storage medium comprises, but not limited to, magnetic disk storage, optical storage, flash memory, and the like.

[0079] The processor 62 may be implemented by discrete hardware components such as a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gates, or transistors. Accordingly, each device such as the judgment device and the determination device may be implemented by a central processing unit (CPU) running instructions that execute the corresponding steps, or may be implemented by a dedicated circuit that executes the corresponding steps.

[0080] The bus 60 may has any of a variety of bus structures. For example, these structures comprise, but are not limited to, an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MAC) bus, and peripheral component interconnects (PCI) bus.

[0081] The computer system may further comprise an input-output interface 63, a network interface 64, a storage interface 65, and the like. These interfaces 63, 64, 65, the memory 61 and the processor 62 may be connected through a bus 60. The input / output interface 63 may provide a connection interface for input / output devices such as a display, a mouse, and a keyboard. The network interface 64 provides a connection interface for various networked devices. The storage interface 65 provides a connection interface for external storage devices such as a floppy disk, a flash disk, or an SD card.

[0082] In the technical solution of the present invention, a bistable relay is adopted in the relay protection circuit, which has the advantages of energy saving and low heat generation of the coil, capable of effectively improving the oxidation phenomenon of the contact and prolonging the service life of the contact. On the other hand, when the voltage of the output connection point (of a contact) is less than the first threshold and not less than the second threshold, the pull-in coil and the release coil are controlled to be alternately powered, so that the contact oscillates and is rapped repeatedly, which can effectively reduce the accumulation of foreign objects on the contact, thereby improving the contact's electrical contact reliability. Therefore, by adopting the technical solution of the present invention, the reliability of the relay protective apparatus can be effectively improved, the service life thereof can be prolonged, and the reliability of the electrical system of the engineering machine can be improved.

[0083] Heretofore, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concepts of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can understand how to implement the technical solutions disclosed herein.

[0084] Parts of the description and drawings referring to embodiments which are not covered by the claims are not presented as embodiments of claimed subject matter but as background examples useful for understanding the invention and may, if applicable, provide details to further specify embodiments claimed or described in this application.

[0085] Although some specific embodiments of the present disclosure have been described in detail by way of example, those skilled in the art should understand that various modifications are possible to be made, without departing from the scope of the present invention, which is defined by the appended claims.

Claims

1. A relay protective apparatus, comprising: a power input connection point (J4) which is a terminal of the relay protective apparatus to connect with an external system power supply; a relay protection circuit, comprising a bistable relay (K1) and an output connection point (J1), the bistable relay (K1) comprising a contact (H1), a pull-in coil (Q11) and a release coil (Q12), wherein an input terminal of the contact (H1), an input terminal of the pull-in coil (Q11) and an input terminal of the release coil (Q12)are connected to the power input connection point (J4), and an output terminal of the contact (H1) is connected to the output connection point (J1), and the output connection point (J1) is a terminal of the relay protective apparatus to connect with an external power circuit; and a central controller (100), comprising a first port (D11, D21, D31) connected to the output connection point (J1), a second port (D12, D22, D32) connected to an output terminal of the pull-in coil (Q11), and a third port (D13, D23, D33) connected to an output terminal of the release coil (Q12), wherein under a control of the central controller (100), the pull-in coil (Q11) and the release coil (Q12) are powered alternately to make the contact (H1) be opened and closed frequently, in response to a voltage of the output connection point (J1) being less than a first threshold and not less than a second threshold, wherein the first threshold is less than a standard operating voltage of the bistable relay (K1), and the second threshold is a minimum allowable operating voltage of the bistable relay (K1).

2. The relay protective apparatus according to claim 1, wherein: the central controller (100) triggers the pull-in coil (Q11) to close the contact (H1) if the voltage of the output connection point (J1) is not less than the first threshold or a number of times the contact (H1) oscillating continuously is not less than a preset number of times; and the central controller (100) acquires the voltage of the output connection point (J1) at every preset interval.

3. The relay protective apparatus according to claim 2, further comprising: a fault indicator (A1); wherein the central controller (100) further comprises a fourth port (D41) connected to the fault indicator (A1), and the central controller (100) also controls the fault indicator (A1) to send a first fault indication information in case that the voltage of the output connection point (J1) is zero; and, controlling the fault indicator (A1) to a send second fault indication information, when the voltage of the output connection point (J1) is greater than zero and less than the second threshold; and the fault indicator (A1) comprises an indicator light or a buzzer.

4. The relay protective apparatus according to claim 1, wherein: the relay protection circuit further comprises a first storage capacitor (C11), wherein the input terminal of the contact (H1), the input terminal of the pull-in coil (Q11) and the input terminal of the release coil (Q12) are further connected to an output terminal of the first storage capacitor (C11); and the relay protection circuit further comprises a fuse-link (F11) connected in series with the bistable relay (K1), wherein an input terminal of the fuse-link (F11) is connected to the output terminal of the contact (H1), and an output terminal of the fuse-link (F11) is connected to the output connection point (J1).

5. The relay protective apparatus according to any one of claims 1 to 4, further comprising: a voltage regulator (9) and a second storage capacitor (C2), wherein: an input terminal of the voltage regulator (9) is used to connect to a power-on output terminal of a key switch; the central controller (100) further comprises a power port (D7), which is connected to an output terminal of the voltage regulator (9) and an output terminal of the second storage capacitor (C2); and the voltage regulator (9) is a low dropout linear voltage regulator (LDO).

6. The relay protective apparatus according to claim 5, wherein: relay protection circuit comprises a power circuit relay protection circuit, a startup circuit relay protection circuit, and a preheating circuit relay protection circuit; and the central controller (100) further comprises a fifth port (D5) for connecting to a startup output terminal of the key switch, and a sixth port (D61, D62) for communicating with a vehicle-mounted controller (20), wherein the central controller (100) controls the power circuit relay protection circuit to work when receiving a power-on signal from the power-on output terminal of the key switch, controlling the startup circuit relay protection circuit to work when receiving a startup signal from the startup output terminal of the key switch in a power-on state, and controlling the preheating circuit relay protection circuit to work when receiving a start-to-preheat signal from the vehicle-mounted controller (20) in the power-on state.

7. The relay protective apparatus according to claim 6, wherein, the sixth port (D61, D62) of the central controller (100) connects with the vehicle-mounted controller (20) through a controller area network (CAN) bus.

8. An engineering machine, comprising the relay protective apparatus according to any one of claims 1 to 7.

9. The engineering machine according to claim 8, wherein, the engineering machine comprises an excavator.

10. A relay protection control method, applied to the relay protective apparatus of claim 1, comprising: acquiring a voltage of an output connection point (J1) of a relay protection circuit (S101); and controlling a pull-in coil (Q11) and a release coil (Q12) of the relay protection circuit to be powered alternately to make a contact (H1) of the relay protection circuit be opened and closed frequently (S102), in response to the voltage of the output connection point (J1) of the relay protection circuit being less than a first threshold and not less than a second threshold, wherein, the first threshold is less than a standard working voltage of a bistable relay (K1), and the second threshold is a minimum allowable working voltage of the bistable relay (K1).

11. The relay protection control method according to claim 10, further comprising: triggering the pull-in coil (Q11) of the relay protection circuit to close the contact (H1), if the voltage of the output connection point (J1) is not less than the first threshold or the number of times the contact (H1) oscillating continuously is not less than a preset number of times; sending a first fault indication information, if the voltage of the output connection point (J1) of the relay protection circuit is zero; and sending a second fault indication information, if the voltage of the output connection point (J1) of the relay protection circuit is greater than zero and less than the second threshold.

12. The relay protection control method according to claim 10, wherein acquiring a voltage of an output connection point (J1) of a relay protection circuit (S101) comprises: acquiring the voltage of the output connection point (J1) of the relay protection circuit at every preset interval.

13. A relay protection control apparatus, comprising: units configured to perform the relay protection control method described in claim 10.

14. A relay protection control apparatus, comprising: a memory (51); and a processor (52) coupled to the memory, the processor being configured to execute the relay protection control method described in any one of claims 10 to 12 based on instructions stored in the memory.

15. A non-transitory computer-readable storage medium on which a computer program is stored, which when executed by a processor implements the relay protection control method according to any one of claims 10 to 12.