143results about How to "Avoid damage accidents" patented technology

The invention relates to an automatic sealing machine and a program-controlled method. A transmission bracket driven through a gear rack and a motor is installed in an overall bracket, and a compression spring, a sealing handle and a stamp connected through a thread through-hole are installed in the transmission bracket. The sealing handle is pressed between the compression spring and a transmission bracket bottom board. The automatic sealing saves the manual trouble, is time-saving and labor-saving. The arrangement of the compression spring ensures that the descending process of the stamp becomes the optimal sealing process, avoids the damage to the motor, and provides a transient time from the stamp pressing to the stamp lifting. After the sealing handle is taken out, the stamp oil is very convenient to be refilled from the through-hole. A single-chip microcomputer is arranged and controlled through a program; a DC motor two-way drive circuit including a field effect pipe, the loss is low, the directional change is quick and the control is convenient. A photoelectric detector can be used for detecting whether the paper is in place, then the motor is controlled to rotate in the forward direction, the stamp descends; the motor is stopped; when the motor rotates in the reverse direction, the stamp ascends; the run-down time is controlled through the program, thereby the sealing is standard, and the effect is good. The automatic sealing machine can be separately used, and can also be matched with any program control system requiring automatic sealing, such as the printing, the separating and the feeding systems of an automatic paying and invoicing terminal.

The invention discloses a control method of an electronic expansion valve of an automobile air conditioner system. The method includes acquiring a result of the judgment of whether the electronic expansion valve is currently in the fault state or not according to the acquired current openness, actual overheat degree Tsh and preset overheat threshold Tsh_set of the electronic expansion valve while conducting overheating degree control and outputting a control signal to an execution mechanism according to the result of the judgment. By means of the control method, effective fault diagnosis can be conducted on the electronic expansion valve in real time. When the overheat degree is mistakenly controlled, the control signal is output to the execution mechanism to stop work of the system by controlling a compressor to shut down and / or remind operators to conduct fault overhauling by controlling a fault indicator lamp to be turned on, so that accidents of refrigeration system device damage caused by mistaken control can be completely avoided, and system running safety and reliability can be improved.

The invention relates to an integrated fault diagnosis method and a system for turn-to-turn discharging of a transformer. The method comprises the steps of collecting ultrahigh-frequency partial discharging signals, ultrasonic partial discharging signals, pulse current partial discharging signals, primary voltage signals, secondary voltage signals and primary current signals; synchronously collecting and processing the ultrahigh-frequency partial discharging signals, the ultrasonic partial discharging signals, the pulse current partial discharging signals, the primary voltage signals, the primary current signals and the secondary voltage signals for recognizing the source type of partial discharging of the transformer; and comprehensively processing the ultrahigh-frequency partial discharging signals, the ultrasonic partial discharging signals, the pulse current partial discharging signals, the primary voltage signals, the primary current signals and the secondary voltage signals after being processed for obtaining the fault assessment of partial discharging of the transformer and achieving integrated fault diagnosis of turn-to-turn discharging of the transformer.

The invention discloses a device for testing piezoelectric property of an electrostatic spinning PVDF (polyvinylidene fluoride) piezoelectric fiber membrane. A vertical seat is fixed in the rear of a base, a vertical panel capable of moving up and down is arranged on the front side of the vertical seat, one end of the vertical panel is connected with one end of a stepping motor, a motor fixing device is arranged on the vertical panel, one end of the motor fixing device is connected with the upper end of a motor, a spring is fixed to the lower end of the motor, the lower end of the spring is connected with a contactor, a first insulation layer is arranged between the contactor and the spring, a force transducer is arranged under the contactor, a second insulation layer and a conductive layer are arranged on the force transducer which is arranged in the middle of a clamp, and the clamp is arranged on the base through a horizontal panel. The device can measure piezoelectric signals generated by a flexible piezoelectric material under different-size and different-frequency pressure actions so as to characterize the piezoelectric property of the piezoelectric material, and measuring results can be computed to obtain piezoelectric strain constants; the electric signal measurement device is high in precision, good in repeatability and comparability and high in measurement efficiency.

The present invention discloses a tap grounding apparatus used for a transformer bushing. The transformer bushing comprises a base flange provided with a first mounting hole; the tap grounding apparatus comprises a grounding seat, a grounding post and an insulating seat; the insulating seat is fixed in the first mounting hole; a second mounting hole is formed in the insulating seat; the grounding post is fixed in the second mounting hole; a grounding seat cover is arranged on the first mounting hole and fixedly connected to the base flange; the upper end of the grounding post is detachably connected to the grounding seat; one of the grounding seat and the grounding post is provided with a pin terminal; and the other of the grounding seat and the grounding post is provided with a jack capable of allowing the pin terminal to be inserted and connected. According to the tap grounding apparatus, the grounding reliability can be effectively improved and a poor grounding situation caused by a defect of a grounding connector can be conveniently discovered; and the tap grounding apparatus is simple in structure and low in manufacturing cost. The present invention also discloses a transformer bushing. The transformer bushing is provided with any tap grounding apparatus.

The invention discloses a long wall coal mining roof pressure hydraulic support resistance change characteristic pre-warning method. A hydraulic support working resistance monitoring device, a pump station switch monitoring device and a hydraulic support resistance change index dynamic monitoring system are used for pre-warning; the hydraulic support working resistance monitoring device is used for recording and storing monitored working face hydraulic support working resistance and corresponding time in real time; the pump station switch monitoring device is used for recording and storing monitored working face hydraulic support injection pump pressure finishing time; the hydraulic support resistance change index dynamic monitoring system is used for processing and analyzing received data, marking a hydraulic support working resistance value corresponding to the working face hydraulic support injection pump pressure finishing time as hydraulic support setting load, and pre-warning about working face roof pressure according to the change of resistance change index values. Accurate and timely pre-warning about abnormal roof pressure can be realized, and normal periodic weighting length can be accurately determined in real time.

The invention provides a control system for a turbine, which comprises a safety monitoring unit, a digital electro-hydraulic control unit, an operator station, an oil engine controller and a distributed control unit, wherein an emergency tripping unit is arranged in the control system; when a halting signal is monitored by the safety monitoring unit, the distributed control unit or the digital electro-hydraulic control unit, an electric signal is sent to the emergency tripping unit; and the emergency tripping unit can realize the two functions of sending a control signal for performing loop check on a field failure line to the distributed control unit or sending a shutdown signal to a main throttle valve switch and sending the halting signal of the oil engine controller to the digital electro-hydraulic control unit. An emergency tripping function, a safety monitoring function, a digital electro-hydraulic control function, a servo control function and a distributed control function are integrated on the control system for the turbine; the data collision and the personnel investment can be reduced; an on-line debugging function of a machine set is realized; and the control system has double-machine state tracking and interlocking functions and can undertake the main control and monitoring protecting functions of a turbine generator set.

The invention discloses a three-way valve with an electromagnetic pilot sliding valve for an air-conditioner water heater. According to the technical scheme, the three-way valve comprises a main sliding valve, the electromagnetic pilot sliding valve and an electromagnetic coil, wherein the electromagnetic pilot sliding valve comprises a pilot valve body, a pilot valve core, a restoring spring, a sliding diversion cap, an air inlet capillary, a left capillary, a middle capillary and a right capillary. The three-way valve is characterized in that: the main sliding valve comprises a main valve body, pistons, a plate-like piston rod, an air distribution valve block and a spring sheet; two pistons connected with the plate-like piston rod partitions the cavity of the main valve body into a left air chamber, a middle air chamber and a right air chamber; the middle air chamber is provided with an air inlet pipe joint and two air outlet pipe joints connected to double holes of a valve seat; the left and right capillaries are connected with the left and right air chambers of the main valve body, the air inlet capillary is connected with a branch pipe of the air inlet pipe joint, and one end of the middle capillary is open and connected with a low-pressure pipeline of a refrigerating loop; and the position of the pilot valve core and the pressure of the left and right air chambers of the main valve body are changed by power-on and power-off of the electromagnetic coil, so that the pistons and the plate-like piston rod shift, the orifice of an air distribution valve block sealing cover is changed and an air outlet passage is switched.

The present invention discloses a differentiation lightning protection method of an urban area 10KV distribution line. The differentiation lightning protection method of urban area 10KV distribution line comprises: selecting a 10KV distributing line to be included in a lightning positioning system, lightning arresters on typical urban area 10KV distribution lines being all provided with discharge counters; obtaining electric parameters of the typical urban area 10KV distribution lines, the lightning parameters of the line areas and building information surrounding the lines; performing a lightning strike risk assessment of the typical urban area 10KV distribution lines; checking the motion conditions of the discharge counters after thunderstorm every time, and obtaining properties of lightning overvoltages to determine a finally adopted differentiation lightning protection measure; and determining a lightning protection measure. According to the invention, the lightning positioning system and the discharge counter are applied to the distribution lines, corresponding precautionary measures are pointedly made out, and accidents of damaging distribution lines and electrical equipment caused by frequent occurrence of overvoltage are avoided. Moreover, the differentiation lightning protection method of an urban area 10KV distribution line may pointedly perform 10KV distribution line differentiation lightning protection according to economical, obstructive and guiding differentiation lightning protection principles.

The invention discloses a greenhouse roller blind control system and a working method of the greenhouse roller blind control system. The greenhouse roller blind control system comprises a roller blind controller, a non-contact reversing module, a roller blind machine upper connection rod, a roller blind machine lower connection rod, a hinge a, a hinge b, a roller blind machine, an angle sensor a, an angle sensor b, an upper dead center limiting switch and a lower dead center limiting switch. The working method includes the steps of initializing the state, expanding the heat preservation quilt and roller blind machine power-off protection process and unfolding the heat preservation quilt. The greenhouse blind control system and the working method of the greenhouse roller blind control system have the advantages that the actual operation state of the roller blind machine can be detected by the system, fault alarming can be achieved, executing mechanisms such as a motor, a speed reducer and the heat preservation quilt are protected, equipment damage caused by maloperation is reduced and avoided, automatic and remote adjusting of the greenhouse environment can be achieved, the dependence degree on workers can be accurately and obviously reduced in time, management and operation cost is reduced, and the operation safety and the economic benefits of facility cultivation are effectively improved.

The invention discloses a detection system for a capacitive bushing provided with a voltage measurement terminal and an end-screen ground terminal. The detection system comprises a bushing, an alarm module and a circuit breaker. The system further comprises a voltage detection circuit and a current detection circuit, wherein the voltage detection circuit and the current detection circuit are used for detecting the change of the electric field and the change of the current inside the bushing. The voltage detection circuit and the current detection circuit are connected in series and then are connected between the voltage measurement terminal of the bushing and a grounding point. Voltage and current measurement signals are sent to a monitoring and protection processing module to be processed. The output end of the monitoring and protection processing module is connected with the alarm module and the circuit breaker. The monitoring and protection processing module judges whether the bushing breaks down or not according to the detected change value of the voltage and the detected change value of the current. Based on the system, the state of the bushing can be monitored, so that the bushing can be reliably protected.

The invention discloses a method for controlling manual gear shift of an automatic transmission. The method is characterized in that according to the performances of an engine, the maximum rotation speed valve of the engine of each shift, to which the transmission can be reduced, is restricted; when down shift is carried out by a driver, if the current rotation speed of the engine is too high, when the transmission reduces to the low shift, the rotation speed of the engine is higher than the restriction shift, explosion accident may occur on the engine, if so, inconvenience may be brought to the driver of the vehicle, and certain damage can be caused to the engine. So according to the performances of the engine, the maximum rotation speed valve of the engine of each shift, to which the transmission can be reduced, is restricted, when down shift is carried out by the driver, if the rotation speed of the engine is higher than the restricted maximum rotation speed of the engine, the gear shift requirement is neglected, thus the engine can be protected effectively, and the occurrence of damage accident of the engine caused by the subjective faulty operation by the driver is avoided.

The invention discloses an intelligent leakage protector provided with broken null line protection function. The intelligent leakage protector comprises a high-precision zero sequence CT, a first logic circuit, a high-precision broken null line detection CT, a second logic circuit, and a control circuit, wherein the high-precision zero sequence CT is connected onto a three-phase AC electric power line passage, and is used for collecting three-phase out-of-balance current Ior; the first logic circuit is connected with the zero sequence CT, and sends out a first logic signal when the three-phase out-of-balance current Ior surpasses a first threshold value; the high-precision broken null line detection CT is used for collecting natural current In; the second logic circuit is connected with the broken null line detection CT, and sends out a second logic signal when the natural current In surpasses a second threshold value; the control circuit acquires the first logic signal or the second logic signal, confirms that a return circuit broken null line breakdown occurs and generates a warning signal when the three-phase out-of-balance current Ior is greater than the first threshold value and the natural current In is smaller than the second threshold value. The intelligent leakage protector can accurately diagnose a broken null line breakdown and sends out a tripping command to conduct error correction and prognosis interrupt processing on signal processing.

The invention provides a greenhouse roller shutter control mechanism and method. The mechanism comprises a heat preservation quilt, a roller shutter machine, a supporting structure, a controller and a motor reversing mechanism, wherein the heat preservation quilt covers a greenhouse film of a greenhouse, the roller shutter machine is fixed to a rolling shaft of the heat preservation quilt, the supporting structure is hinged to the ground and fixedly connected with the roller shutter machine, the controller controls the roller shutter machine to operate, and the motor reversing mechanism is connected with the controller and controls the operation direction of the roller shutter machine; the supporting structure comprises an upper connecting rod, a lower connecting rod and an angle encoder, wherein one end of the upper connecting rod is fixed to the roller shutter machine, the lower connecting rod is connected with the upper connecting rod in a hinged mode and hinged to the ground, and the angle encoder is fixed to any hinge connection position and is in signal connection with the controller. According to the technical scheme, the greenhouse roller shutter control mechanism is simple and firm in structure, low in cost, high in automation degree, high in system control precision and great in reliability.

The invention relates to an automatic control system for a parking lot barrier. The system comprises front end equipment and ground equipment, wherein the front end equipment comprises a tripod head, a protective cover, an image sensing device, a 1394 dedicated circuit and an illumination supplementary lamp; the image sensing device is bridged on the tripod head and positioned in the protective cover; the ground equipment comprises a control computer, a barrier and an RS232 dedicated circuit; the image sensing device is connected with the control computer through the 1394 dedicated circuit; and the control computer is connected with the barrier through the RS232 dedicated circuit. The specific operation process of the system comprises the following steps that: the control computer transmits a signal; the image sensing device starts to work after receiving the signal and transmits the acquired information to the control computer through the 1394 dedicated circuit. Compared with the prior art, the automatic control system for the parking lot barrier has the advantages of high automation degree, simple structure, low cost, high identification precision and the like, and is safe.

The invention relates to a bath temperature-display handle shower. A temperature measuring and displaying device of the temperature-display handle shower comprises a display panel arranged on a handle shower shell and a temperature measuring sensor arranged in a water flow channel of the handle shower. The temperature-display device and the water flow channel are sealed and separated. According to the technical proposal, the temperature measuring sensor is arranged in the water flow channel in the handle shower, so that water temperature signals acquired by the temperature measuring sensor can be displayed in a digital mode by the display device through a processing module arranged on the temperature-display device. Thus, the temperature state and change of water flow can be observed clearly through the display device, and discomfort and injuries to a human body which contacts the water flow for adjusting the temperature of shower water are avoided.

The invention discloses an aircraft undercarriage driving device, an aircraft undercarriage and an aircraft. The aircraft undercarriage driving device comprises a first support arm plate, a second support arm plate, an undercarriage seat, a driven arm and an actuating arm, wherein the first support arm plate and the second support arm plate are fixedly connected below a rack, a first chute is formed in the first support arm plate, and a second chute is formed in the second support arm plate; the undercarriage seat can be rotationally arranged between the first support arm plate and the second support arm plate through a rotating shaft, and a hinged part is bulged on the undercarriage seat; one end of the driven arm is hinged to the hinged part through a hinged shaft, and two ends of the hinged shaft are glidingly clamped to the first chute and the second chute respectively; one end of the actuating arm is hinged to the other end of the driven arm, and the other end of the actuating arm is connected with an actuator. The aircraft undercarriage can be stably and accurately positioned in retracting and deploying positions.

The invention provides a sand spraying firefighting device for a transformer substation, which can implement automatic control and improve the diversity of firefighting monitoring and automatic fire-extinguishing functions of the transformer substation so as to reach effective prevention and extinguishing effects. The sand spraying firefighting device comprises a control system, an unmanned aerialvehicle, a fire-extinguishing unit, a firefighting sand recycling device and transformer substation equipment, wherein the control system is used for controlling flight action of the unmanned aerialvehicle and is used for investigating fire behaviors; after an investigating signal of the unmanned aerial vehicle is analyzed and calculated, a corresponding control signal is sent out according to apre-set program to a firefighting unit; the unmanned aerial vehicle is used for receiving instruction action and an investigating direction of the control system and transmitting investigating data to the control system; the firefighting unit is used for receiving a control signal of the control system and carrying out firefighting action; the firefighting sand recycling device is used for recycling, circulating and reutilizing firefighting sand which is used by the transformer substation equipment and the periphery. By adopting the sand spraying firefighting device provided by the invention,a pipeline maintenance problem of a common foam or water spraying device is solved and equipment damage accidents which are possibly caused by false operation of oil discharging and nitrogen injection are avoided, so that effective prevention and extinguishing effects are realized.

The invention discloses a bead feeding mechanism of a fully-automatic loading and unloading switcher and a bead feeding method thereof. The bead feeding mechanism comprises a bracket, the upper end of the bracket is fixedly provided with a receiving box, the bottom of the bracket is provided with a bead feeding cylinder, a piston rod of the bead feeding cylinder is provided with a bead loading plate linked and matched with the bead feeding cylinder, the bead loading plate can movably pass through the bottom of the receiving box, and the bead loading plate is fixedly provided with a die needle side by side, the bracket is provided with a vibratory bead cylinder opposite to the side wall of the piston rod of the bead feeding cylinder, the head end of a piston rod of the vibratory bead cylinder is fixedly provided with a vibrating plate, and the piston rod of the bead feeding cylinder relative to the upper end of the vibrating plate is fixedly provided with a vibrating block which is clamped and matched with the vibrating plate in the extending direction of the piston rod of the bead feeding cylinder. The bead feeding mechanism has the advantages of good stability, low failure rate, high production efficiency, and the like.

The invention provides a steel plate straightening method which is used for a steel plate straightening machine. The steel plate straightening method includes the steps that the roughness of a head ofa steel plate is judged; if the roughness is greater than a preset value, then a roll seam of the steel plate straightening machine opens to the position of a first roll seam which is greater than the roughness, and the steel plate passes through the steel plate straightening machine at a first preset speed; after the tail portion of the steel plate passes through the steel plate straightening machine, the roll seam is lowered to the position of a preset roll seam to make the steel plate move in an opposite direction, and then reverse straightening is carried out on the steel plate through the steel plate straightening machine; and if the roughness is less than the preset value, then forward straightening is carried out on the steel plate through the steel plate straightening machine. According to the technical scheme of the steel plate straightening method, by the reverse straightening, the problem of difficult biting of the straightening machine when a steel plate head is cocked issolved; after being straightened reversely, the steel plate is moved into a next process in a forward direction, and upstream and downstream processes are smoothly connected without the need for adding additional invest; the whole steel plate straightening process is automatically controlled with no manual intervention required, so that the labor intensity of workers is reduced, and the possibility of the accident of equipment damaging caused by man-made operational errors is effectively lowered.

The invention provides a hoisting steel wire rope tension control device, which comprises a tie rod (7) installed on the machine platform (2) through a tie rod bracket (8) close to the direction of the hoist (4) on the machine platform. The upper end of the rod (7) is provided with a three-pulley assembly (5), and the three-pulley assembly (5) includes two installation side plates (19) symmetrically arranged front and back, and the installation side plates (19) are arranged between There are three pulleys, wherein the left pulley (11) and the right pulley (17) are symmetrically fixed on the installation side plate (19), and the middle pressure roller (12) is movably installed between the two side plates. By setting this device on the machine table close to the end of the hoisting rope, the tightness of the hoisting can be monitored at the end of the hoisting rope. Once the tension of the wire rope is insufficient, the travel switch can be passed in time to control the suspension of the hoisting and stop the rope. Prevent the occurrence of accidents that cause damage to the steel wire rope after hoisting and skipping the rope.

The invention discloses an impact crusher. The impact crusher comprises a main body housing which is provided with a feed port and a discharge port; a rotor is arranged in an inner cavity of the main body housing, and a main shaft of the rotor is connected to a power transmission mechanism outside the main body housing; a first impact plate, a second impact plate and a flattening device are arranged on the inner wall of the main body housing and respectively form crushing chambers with the rotor; the feed port is formed right above the crushing chamber formed between the first impact plate and the rotor; the discharge port is formed below the crushing chamber formed between the flattening plate and the rotor; a liner plate is mounted at a quick-wearing part of a crusher body. With such structure, the impact crusher can effectively avoid the damage accident caused by the impact of the material to the crusher body and a civil foundation, and also can improve the crushing efficiency and effectively reduce the discharging granularity as well as improve the passing rate of the finished products. The impact baffle device has the advantages of being simple in structure, convenient to mount and maintain, and safe and reliable in operation.

A stall-eliminating blower for blowing or exhausting is composed of casing, motor, vane wheel and airflow collector, and is characterized by its additional reverse-flow unit, which can make the eddy flow caused by stall flow reversely back to main flow channel, so eliminating stall.

The invention relates to an anti-sticking material bulk cargo storage bin. The storage bin is characterized in that two corresponding side plates of the bulk cargo storage bin are such side plates that the lower part gradient is 70 degrees, and the upper part gradient is 50 degrees; the top ends and the bottom ends of the two side plates are respectively provided with a top guide hole and a bottom guide hole, the inner walls of the two side plates are provided with lining boards, and the outer walls of the two side plates are provided with wing plates; the two side plates are respectively provided with an anti-sticking material mechanism; and each anti-sticking material mechanism comprises a support, a tension roller arranged on the support, a top guide roller arranged on the top of each wing plate, a bottom guide roller arranged on the bottom of each wing plate, a bearing base arranged on the middle of each wing plate, a driving roller rotatably connected with the bearing base, a motor connected with the driving roller, a strap which can pass through the top guide hole and the bottom guide hole and is respectively connected with the top guide roller, the tension roller, the driving roller and the bottom guide roller, and a U-shaped scraper arranged on the lower part of each wing plate. The bulk cargo storage bin provided by the invention has the advantages of reducing the labour intensity of workers, and avoiding occurrence of accident of next stage equipment damage caused by bulk dropping due to excessive sticky materials.

The invention discloses a device for controlling the safe pressure of a horizontal balance system of a rolling mill. The device comprises an electric control system and a hydraulic execution system connected with the electric control system through a data line, the electric control system comprises a CPU (Central Processing Unit), a PI (Proportional Integral) regulator, a amplitude-limiting generator, an input / output board and a pressure flow conversion module, can calculate corresponding pressure values according to different cascading modes of the rolling mill and then limit the amplitude so as to output minimum balance force. Accordingly, the invention also discloses a method for controlling the safe pressure of the horizontal balance system of the rolling mill. The method is simple and convenient to operate and can ensure the long-term safe and stable operation of the system.

The invention discloses a warning system of a reel sprinkler, which comprises a wireless transmitter (5) mounted inside a sprinkler reel (1), reelpipe monitoring devices (4) mounted at two ends of the reel, and a wireless receiver and a display mounted inside a cab; wherein a flip-up switch (3) is mounted on a water pipe winding face of the reel in the axial direction and is connected with the reelpipe monitoring device and the wireless transmitter; and the wireless receiver is connected with the display. Compared to the prior art, the warning system monitors the pipe releasing condition of the reel through wireless signals; in the sprinkler pipe releasing process, the situation that when a water pipe is about to be completely pulled out of the reel, the warning system can give a warning timely to remind an operator of the length of the left water pipe so as to stop pipe releasing is achieved through the combination of the display and an audible and visual alarm, and accordingly the accident that the water pipe is overly pulled to cause damages to devices is avoided; the work efficiency of the sprinkler is improved; and the normal producing operation is guaranteed.

The invention relates to a recyclable SF6 gas discharging device which comprises a gas recycling bottle, a high-pressure gas pump communicated with the gas recycling bottle through a first high-density plastic pipe, and a gas flow control valve communicated with the high-pressure gas pump through a second high-density plastic pipe. The recyclable SF6 gas discharging device is convenient to carry and easy to operate; the working efficiency is greatly improved; the human safety is guaranteed; the environment pollution is avoided; the signal transmission precision is guaranteed, and the working efficiency is effectively improved; discharged SF6 gas can be recycled; the SF6 gas is prevented from being directly discharged and harming the human safety; the atmospheric environment is protected; and the green and environmentally-friendly overhaul is realized.

The invention proposes an intelligent low-voltage cable branching box, a running method thereof and an intelligent power distribution area. The intelligent low-voltage cable branching box comprises anintelligent monitoring terminal, a main bus, an isolation switch, a box door travel switch and intelligent residual current action circuit breakers, wherein the intelligent monitoring terminal is connected with a power cable at a power side of the isolation switch via a low-voltage power line, the intelligent monitoring terminal is connected with an auxiliary switch of the isolation switch and the box door travel switch via a control cable, one end of the main bus is connected with a load side of the isolation switch, and the other end of the main bus is connected with at least two intelligent residual current action circuit breakers. A low-voltage power line carrier communication technology is employed, the power cable is used as a communication medium, running data acquisition and transmission of the power distribution area are achieved, the intelligent low-voltage cable branching box has the technical advantages of wiring free, performance stability, communication channel reliability, consistent physical reliability of the low-voltage power distribution network and the like and is simple to construct and convenient to maintain and manage, and the coverage range and the low-voltage power distribution network are consistent.

The invention discloses an overrun protection and releasing system for a numerical control machine tool, and relates to an improvement for an overrun protection and releasing method for the numerical control machine tool. The overrun protection and releasing system is mainly used for performing safety protection on overrun of the numerical control machine tool and releasing. When an overrun alarm of the machine tool occurs and overrun releasing is performed on the machine tool, machine tool damage accidents such as machine tool impact and derailing from a guide rail caused by error determination for the operation direction of the machine tool are prevented. The overrun protection and releasing system comprises a driving system, an electric control circuit, an I / O interface circuit of a PLC and a PLC programmable controller. The overrun protection and releasing system can realize automatic determination for the overrun direction of the machine tool. When an overrun releasing operation is performed, if an operation direction is wrong, driving for the shaft of the machine tool cannot operate because of no enabling signal; and when the operation direction is right, the enabling signal for the machine tool is normal and the shaft of the machine tool leaves an overrun limit switch, the overrun alarm is released automatically, thereby preventing machine tool damage accidents caused by an operation mistake of an operator. The overrun protection and releasing system for the numerical control machine tool has advantages of simple structure, easy realization, convenient use, high safety, high reliability, low maintenance cost and low manufacture cost.