CN113029828A - Intelligent test system for testing impact mechanical products - Google Patents
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Abstract
The invention discloses an intelligent test system for testing impact mechanical products, which comprises a measurement and control host control system, a pressure flow control device, a vertical test bed and an energy absorber; the measurement and control host control system comprises a signal acquisition input end, a measurement and control host, a controller and a data processing system; the controller and the data processing system set a trigger pressure estimated value and a flow estimated value of the test system; the test host controls the pressure flow control device to supply air to the prototype according to the flow pre-estimated value, controls the pressure flow control device to enable the pressure to reach the system set pressure value pre-estimated value, and achieves closed circulation of pressure feedback and control. The intelligent test system for testing the impact mechanical products can adjust and stably control the pressure and the flow to be intelligently matched in real time, greatly improve the detection efficiency and accuracy of the impact mechanical product test, improve the real-time performance, accuracy and intelligence of data collection and output, and has wide range of test objects and strong applicability.
Description
Technical Field
The invention relates to the technical field of performance testing of impact mechanical products, in particular to an intelligent testing system for testing the impact mechanical products.
Background
The impact mechanical product is an important component in the engineering machinery industry in China, and the product has wide application in the aspects of developing mineral reserves, digging mountains and building roads, making and repairing water conservancy, digging tunnels, building war preparation works and other earthwork projects, realizing manual operation mechanization and the like.
The performance parameters of the impact mechanical product mainly comprise parameters such as impact energy, impact frequency, air consumption (pneumatic type) and noise, the parameters mainly reflect the work efficiency and energy consumption indexes of the rock drilling equipment in the using process, and the parameters are mainly used for measuring the grade of the equipment and are also main indexes for comparing the product quality of various manufacturers.
The domestic detection system can only preliminarily realize automatic acquisition and processing of data, pressure control is mainly controlled manually, automatic pressure control cannot be realized, and the pressure fluctuation range is large and cannot be accurately controlled during testing; the air consumption data is obtained by reading the scale number of the flowmeter and recording the environmental conditions on site, the air consumption at a certain time point is calculated according to the measured environmental temperature, humidity, local air pressure and the scale number of the flowmeter, and the final air consumption is determined by measuring several time points and averaging; the data processing system has low operation speed, only the data input end of the system processes the acquired data, and only the data input end passively receives the acquired data, so that intelligent control cannot be realized. The whole testing process is low in efficiency, poor in data accuracy and low in instantaneity.
Disclosure of Invention
In view of this, the present invention provides an intelligent testing system for testing an impact-type mechanical product, which is used for adjusting and stably controlling pressure and flow in real time to intelligently match, greatly improving detection efficiency and accuracy of the impact-type product test, improving instantaneity, accuracy and intelligence of data collection and output, and having a wide range of test objects and strong applicability.
In order to achieve the purpose, the invention adopts the following technical scheme: an intelligent test system for testing impact mechanical products comprises a measurement and control host control system, a pressure flow control device, a vertical test bed and an energy absorber; the measurement and control host control system comprises a signal acquisition input end, a measurement and control host, a controller and a data processing system; the information collected by the signal collecting input end comprises strain information, flow information, pressure information, temperature information, vibration information and rotating speed information; the information signals received by the test host comprise strain signals, flow signals, pressure signals, temperature signals, vibration signals and rotating speed signals; the test host comprises a conditioning module and an acquisition module, wherein the conditioning module of the test host converts acquired analog signals into digital signals through analog-to-digital conversion and stores the digital signals in the acquisition module; the controller and the data processing system set a trigger pressure estimated value and a flow estimated value of the test system, and the acquisition module contrasts and analyzes the system set trigger pressure estimated value and the flow estimated value of the controller and the data processing system; and the test host controls the pressure flow control device to supply air to a prototype according to the flow pre-estimated value, controls the pressure flow control device to enable the pressure to reach the system set pressure value pre-estimated value, and realizes closed circulation of pressure feedback and control.
Further, the pressure flow control device comprises an air storage tank, a frame, a first stop valve, a temperature transmitter, a pressure air pipeline, a fourth pilot-operated electromagnetic valve, a fourth stop valve, a fourth vortex flowmeter, a pilot-operated pressure regulating valve, a second stop valve, a third vortex flowmeter, a first vortex flowmeter, a second vortex flowmeter, an electric regulating valve, a third pilot-operated electromagnetic valve, a second pilot-operated electromagnetic valve, a first pilot-operated electromagnetic valve and a third stop valve; the air compression pipeline and the air storage tank are arranged on the frame, and the air compression pipeline sequentially comprises a first air inlet main path, a parallel flow monitoring branch path, a second air inlet main path, a first air outlet main path, a parallel air outlet branch path and a second air outlet main path along the airflow direction; the air inlet of the air storage tank is communicated with the second air inlet main path, and the air outlet of the air storage tank is communicated with the first air outlet main path; the first main air inlet path is sequentially provided with a pilot type pressure regulating valve and an electric regulating valve along the air flow direction; the pressure transmitter is arranged at the gas holder; the two branches of the parallel air outlet branch are respectively provided with a fourth pilot type electromagnetic valve and a fourth stop valve, and the second air outlet main path is provided with a first stop valve; the parallel flow monitoring branch is a three-level flow monitoring branch which is arranged in parallel, a first pilot type electromagnetic valve and a first vortex shedding flowmeter are arranged on a first-level flow monitoring branch, a second pilot type electromagnetic valve and a second vortex shedding flowmeter are arranged on a second-level flow monitoring branch, and a third pilot type electromagnetic valve and a third vortex shedding flowmeter are arranged on a third-level flow monitoring branch; the first vortex shedding flowmeter, the second vortex shedding flowmeter and the third vortex shedding flowmeter have different measuring ranges.
Furthermore, the pressure gas pipeline also comprises a stop branch which is connected with the parallel flow monitoring branch in parallel, the stop branch is sequentially provided with a third stop valve, a second stop valve and a fourth vortex shedding flowmeter along the airflow direction, and the gas outlet end of the pilot type pressure regulating valve is communicated with the gas inlet end of the second stop valve.
Furthermore, the energy absorber group comprises a plurality of energy absorbers with different energy absorption efficiency grades; the energy absorber consists of a drill rod, an upper flange plate, an energy absorber shell, an energy absorbing wafer, a cushion pad, a lower flange plate, a gland and plastic ointment.
Furthermore, the vertical test bed consists of an air inlet pipeline of the air cap, a two-position four-way valve, a pressure regulating valve, a pressure gauge, a lifting device, a stand column, the air cap, a pressing and rotating auxiliary supporting device, a calibration device, a base, a speed measuring device and an air inlet pipeline of a prototype.
The impact energy detection method of the intelligent test system for testing the impact mechanical products comprises the following steps: s1, pasting a strain gauge, and performing a calibration test after the strain gauge is pasted to determine a calibration coefficient; s2, determining a calibration coefficient B; and S3, measuring and calculating impact energy.
Further, the calibration method in step 2 is as follows:
drop weight and drop weight height according to a certain mass
h＝2218-l-h0---(1)
In the formula, the free falling height of the h-drop hammer is mm;
l-drop length, mm;
h0-calibrating the distance, mm, from the lower end face of the shank to the upper end face of the shank adapter of the energy-absorbing test drill rod;
2218-calibrate the length of the tube;
the falling hammer is completely converted into kinetic energy, namely impact energy at the moment that the falling hammer impacts a test drill rod from potential energy at a certain height, and the formula is as follows:
E＝mgh----(2)
in which E-drop hammer potential (equal to the impact energy input to the test system), J;
m-drop weight, kg;
g-acceleration of gravity, m/s2；
h-drop height of drop hammer, m;
substituting the falling weight potential energy shown in the formula (2) into the known standard energy E
Automatically processing data by a data processing system, calculating, and finally outputting a calibration coefficient B:
in which a-m is the cross-sectional area of the drill rod2；
Rho-test of density of drill rod material, kg/m3；
c-the propagation speed of the stress wave in the test drill rod, m/s;
b-stress/unit quantization value, i.e. scaling factor, N/(m)21 number);
Δ t-sample time, s;
nj-the digital quantity of the measured voltage corresponding to the jth stress value, in units of 1 digit;
j-the number of integration points;
wherein
And the stress wave data are automatically calculated by the acquisition and conditioning module and the data processing system according to the acquired stress wave data.
Further, the method for measuring and calculating the impact energy in the step 3 comprises the following steps: the wave has certain energy when propagating in the drill rod, a certain fixed section in the drill rod has stress P and speed v, and the total energy is Pvddt when acting in dt time
In the formula, A is the sectional area of a drill rod;
r is the duration of the wave;
The complete energy transfer can be realized under the condition that the piston collides with the sectional area of the drill rod and the drill rod is long enough; energy of incident wave
In the formula, Vp-collision velocity of piston
M-piston mass
m-shank fluctuation inertia
Capturing the stress course of one point in a drill rod by adopting a proper transient stress recording means according to the impact energy of the rock drilling in the formula (4), and then determining by squaring and solving the product;
in the test system, the stress value in the function is converted into a voltage quantity, the voltage quantity is converted into a digital quantity through A/D (analog/digital), the middle process of calculation is omitted, and finally, the mathematical model of impact energy detection is as follows:
in the formula, E-impact energy, J;
a-test the cross-sectional area of drill rod, m2；
Rho-test of density of drill rod material, kg/m3；
c-the propagation speed of the stress wave in the test drill rod, m/s;
b-stress/unit quantization value, i.e. scaling factor, N/(m)21 number);
Δ t-sample time, s;
nj-the digital quantity of the measured voltage corresponding to the jth stress value, in units of 1 digit;
j-the number of integration points;
in the formula, after the test drill rod material is determined, the values of a, rho and c are also determined, namely constants; when the sampling time is set, delta t is also constant; when the calibration factor B is determined, the impact energy E is only compared with n representing the impact stressj 2In connection with this, the test system automatically collects the data and can calculate the impact energy E.
Furthermore, in the step 3, by using a dynamic strain measurement technology, the test system captures and records the transient stress course of one point in the test drill rod, namely the position where the strain gauge is attached, under the control of a built-in acquisition and conditioning module of the measurement and control host and a data processing system, and then, the impact energy is integrated by at least 30 points with enough integration points.
Further, the method for pasting the strain gauge in the step 1 comprises the following steps:
(1) taking two strain gauges, checking whether the strain gauges are intact or not, and respectively measuring resistance values by using a universal meter to ensure that the resistance values are 120 ohms;
(2) the patch positions are positioned on two symmetrical side surfaces of the drill rod at a position which is about 300mm away from the upper end surface of the drill rod shank of the energy absorption test drill rod; before the surface mounting, firstly, polishing the surface of a drill rod surface mounting piece by using sand paper, and cleaning the surface (at least three times) of the surface mounting piece and the surface around the surface mounting piece by using acetone or absolute ethyl alcohol;
(3) sticking the front surface (the surface without adhesive) of each strain gauge on transparent adhesive tape, coating H-611 adhesive on the cleaned drill rod part uniformly, sticking the adhesive tape and the strain gauge on the drill rod in a preset direction and position, immediately bonding the strain gauge with the drill rod, carefully pressing one end of the strain gauge with one thumb, and pressing the other thumb from one end to the other end with proper force for several times so as to extrude bubbles and stick the strain gauge firmly;
(4) after pasting, connecting one end of two strain gauges in series, reserving two leads, and checking whether the group of strain gauges are connected or not by using a universal meter and whether the resistance value is 240 ohms or not;
(5) after 10 minutes, slightly tearing off the adhesive tape (pressing the lead part), and naturally drying for more than half an hour (the time is determined according to the solidification time of the glue);
(6) wrapping; before binding, insulation treatment between a drill rod and a lead is carried out, generally, two to three layers of insulating adhesive tape paper are laid on the lower portion of a strain gauge lead, a layer of insulating black adhesive tape is laid on the lower portion of a lead joint, and then the strain gauge and the lead joint are tightly wrapped by transparent adhesive tape; the principle of lead wire treatment is that the lead wire is shortest, the welding spot is smallest and the binding is firm;
(7) using a universal meter to check whether the strain gauge is connected or not, whether the resistance value is 240 ohms or not and whether the grounding phenomenon exists or not;
(8) and welding the lead wire of the strain gauge with the signal wire connected with the outside.
The invention has the beneficial effects that:
the intelligent test system for testing the impact mechanical products realizes data acquisition, conditioning and setting control, realizes real-time acquisition and processing of data such as pressure, flow, rotating speed, temperature, vibration speed and the like, can regulate and stabilize the pressure according to the set pressure, ensures the accuracy of flow detection by intelligent flow matching, calculates the sampling data in real time by the processor according to the set algorithm, realizes the real-time output of the calculation result, only needs 3 seconds from the pressure triggering to the result output of the sampling data, and improves the test efficiency. The energy absorber can realize the measurement of different energy-absorbing efficiency grades, has promoted impact energy test range, has also guaranteed the measuring accuracy. The vertical test bed adopts a lifting mechanism, so that the limitation of the structure size of a prototype is eliminated to a great extent, and the universality of the detection equipment is improved.
The intelligent test system for testing the impact mechanical products is mainly applied to the performance detection of the impact mechanical products taking compressed air as power or self-contained power sources such as internal combustion type and electric type. The testing system adopts a visual operation interface, a special data processing system is adopted for parameter setting and data processing, the testing system sets the pressure triggering and flow range estimation through setting, and input pressure is set and controlled to a system set value in real time by using a pressure feedback signal, and the stability of the input pressure is ensured through pressure feedback and control; the shunt electromagnetic valves are intelligently controlled to open corresponding flow shunts by using the flow range estimated value, and the accuracy of the data of the tested gas consumption is improved by setting the flow matching shunts. The test system utilizes a dynamic strain measurement technology to acquire analog signals of frequency, pressure, flow, temperature, rotating speed and the like, utilizes an integrated module for digital conversion, and realizes the acquisition and processing of data of impact energy, impact frequency, gas consumption and the like through intelligent processing of a data processing system. The conditioning module and the acquisition module ensure the real-time performance and the high efficiency of data processing. The test system has great promotion in the aspects of real-time, accuracy and intelligence of data acquisition.
The pressure and flow intelligent measurement and control system can realize accurate pressure adjustment and real-time flow and temperature monitoring, and improve the intelligent degree of detection and control. According to the pressure value set by the system, the pressure range of the compressed air is manually and roughly adjusted through the pilot type pressure regulating valve, the pressure range of the compressed air is controlled in a certain range, the pressure is monitored in real time through the pressure transmitter, the output pressure of the electric regulating valve is controlled and adjusted in real time through the feedback of a pressure signal, the testing pressure is accurately controlled, and the consistency of testing conditions is ensured. According to the gas consumption of the tested equipment, namely the gas consumption flow, the parallel flow monitoring branches of the corresponding flow measuring ranges are distributed, and the accuracy of the gas flow measuring result is improved. The air storage tank reduces and eliminates air flow pulse and fluctuation input by the tested equipment, and ensures the stability of the testing air pressure. The compressed air temperature is monitored in real time through the temperature transmitter, and a gas temperature signal is fed back.
Drawings
FIG. 1 is a general schematic diagram of an intelligent test system for testing an impact-type mechanical product according to the present invention;
FIG. 2 is a schematic diagram of a control system of a measurement and control host according to the present invention;
FIG. 3 is a right side view of the pressure flow control device of the present invention;
FIG. 4 is a front view of the pressure flow control device of the present invention;
FIG. 5 is a top plan view of the pressure flow control device of the present invention;
FIG. 6 is a sectional top view taken along line A-A of FIG. 4;
FIG. 7 is a structural view of a vertical test stand according to the present invention;
FIG. 8 is a block diagram of an energy absorber according to the present invention.
Reference numerals: a measurement and control host control system 1;
the pressure flow control device 2, the air tank 21, the frame 22, the first stop valve 23, the temperature transmitter 24, the pressure transmitter 25, the pressure gas pipeline 26, the fourth pilot-operated electromagnetic valve 27, the fourth stop valve 28, the fourth vortex shedding flowmeter 29, the pilot-operated pressure regulating valve 210, the second stop valve 211, the third vortex shedding flowmeter 212, the first vortex shedding flowmeter 213, the second vortex shedding flowmeter 214, the electric control valve 215, the third pilot-operated electromagnetic valve 216, the second pilot-operated electromagnetic valve 217, the first pilot-operated electromagnetic valve 218, and the third stop valve 219;
the device comprises a vertical test bed 3, an air jacking air inlet pipeline 31, a two-position four-way valve 32, a pressure regulating valve 33, a pressure gauge 34, a lifting device 35, a stand column 36, an air jacking 37, a pressing and rotating auxiliary supporting device 38, a calibrating device 39, a base 310, a speed measuring device 311, a prototype air inlet pipeline 312 and a prototype 313;
the energy absorber 4 comprises a drill rod 41, an upper flange 42, an energy absorber shell 43, an energy absorbing wafer 44, a cushion pad 45, a lower flange 46, a gland 47 and plastic ointment 48.
Detailed Description
The following are specific examples of the present invention and further describe the technical solutions of the present invention, but the present invention is not limited to these examples.
Example 1
An intelligent test system for testing impact mechanical products comprises a measurement and control host control system 1, a pressure flow control device 2, a vertical test bed 3 and an energy absorber 4.
The measurement and control host control system 1 comprises a signal acquisition input end, a measurement and control host, a controller and a data processing system. The information collected by the signal collection input end comprises strain information, flow information, pressure information, temperature information, vibration information and rotating speed information.
The information signals received by the test host machine comprise strain signals, flow signals, pressure signals, temperature signals, vibration signals and rotating speed signals. The test host comprises a conditioning module and an acquisition module, wherein the conditioning module of the test host converts acquired analog signals into digital signals through analog-to-digital conversion and stores the digital signals in the acquisition module.
The controller and the data processing system set a trigger pressure estimated value and a flow estimated value of the test system, and the acquisition module contrasts and analyzes the system set trigger pressure estimated value and the flow estimated value of the controller and the data processing system. The test host controls the pressure and flow control device 2 to supply air to the prototype according to the flow pre-estimated value, and the pressure and flow control device 2 opens the pilot-operated electromagnetic valve of the corresponding air compression loop; the pressure flow control device 2 is controlled to make the pressure reach the system set pressure value estimated value, and the pressure flow control device 2 controls the opening of the electric control valve 215 to realize closed circulation of pressure feedback and control.
The test host collects and stores data to a certain frequency, then transmits the collected data to the controller and the data processing system, the controller and the data processing system output the impact energy, the impact frequency and the rotating speed of the prototype through the operation of a built-in data algorithm, and a detection report is printed through the printing equipment.
Example 2
The present embodiment is different from embodiment 1 in that: the pressure flow control device 2 includes an air tank 21, a frame 22, a first stop valve 23, a temperature transmitter 24, a pressure transmitter 25, a pressure gas line 26, a fourth pilot-operated solenoid valve 27, a fourth stop valve 28, a fourth vortex shedding flowmeter 29, a pilot-operated pressure regulating valve 210, a second stop valve 211, a third vortex shedding flowmeter 212, a first vortex shedding flowmeter 213, a second vortex shedding flowmeter 214, an electric control valve 215, a third pilot-operated solenoid valve 216, a second pilot-operated solenoid valve 217, a first pilot-operated solenoid valve 218, and a third stop valve 219.
The compressed air line 26 and the air tank 21 are provided on the vehicle frame 22. The compressed air pipeline 26 includes a first main air inlet path, a parallel flow monitoring branch path, a second main air inlet path, a first main air outlet path, a parallel air outlet branch path and a second main air outlet path in the airflow direction. The air inlet of the air storage tank 21 is communicated with the second air inlet main path, and the air outlet of the air storage tank 21 is communicated with the first air outlet main path.
The first main intake path is provided with a pilot pressure regulating valve 210 and an electric control valve 215 in this order in the direction of the air flow. A pressure transmitter 25 is provided at the gas tank 21. The two branches of the parallel air outlet branch are respectively provided with a fourth pilot type electromagnetic valve 27 and a fourth stop valve 28, and the second air outlet main branch is provided with a first stop valve 23.
The parallel flow monitoring branch is a three-level flow monitoring branch which is arranged in parallel, a first pilot type electromagnetic valve 218 and a first vortex shedding flowmeter 213 are arranged on a first-level flow monitoring branch, a second pilot type electromagnetic valve 217 and a second vortex shedding flowmeter 214 are arranged on a second-level flow monitoring branch, and a third pilot type electromagnetic valve 216 and a third vortex shedding flowmeter 212 are arranged on a third-level flow monitoring branch; the first vortex shedding flowmeter 213, the second vortex shedding flowmeter 214 and the third vortex shedding flowmeter 212 have different measuring ranges and are respectively DN15, DN25 and DN 40. According to the gas consumption of the tested equipment, namely the gas consumption flow, the vortex shedding flowmeter with the corresponding flow range is reasonably matched, and the corresponding pilot type electromagnetic valve is opened so as to open the matched parallel flow monitoring branch and improve the accuracy of the flow measurement result.
Working process under normal state: the first vortex shedding flowmeter 213, the second vortex shedding flowmeter 214 and the third vortex shedding flowmeter 212 are in a normally open state, the first stop valve 23 is opened, the fourth stop valve 28 is closed, the pressure value and the gas consumption flow value of the test system are set according to the test pressure and the gas consumption reference value of the tested equipment, the flow monitoring shunt with the corresponding range is matched according to the set gas consumption flow value, namely, the first-stage flow monitoring shunt/the second-stage flow monitoring shunt/the third-stage flow monitoring shunt are selected, and the matched parallel flow monitoring shunt is opened by opening a pilot type electromagnetic valve matched with the flow monitoring shunt; the external compressed air is divided into two branches, the first branch of the external compressed air leads the compressed air into a first air inlet main path, roughly adjusts the pressure range through a pilot pressure regulating valve 210, then passes through a fully-opened electric regulating valve 215, enters a parallel flow monitoring branch path which is opened in a matched flow manner to carry out flow measurement, and then enters an air storage tank 21 through a second air inlet main path to attenuate air flow pulses; when the pressure transmitter 26 displays that the pressure reaches the set value of the system pressure, the fourth pilot-operated solenoid valve 27 is opened, so that the compressed air enters the tested equipment through the first stop valve 23; the output pressure is detected in real time according to the pressure feedback signal of the pressure transmitter, and the pressure is stabilized by adjusting the electric regulating valve 215, so that the pressure output is ensured to be the pressure value set by the system.
Example 3
The present embodiment is different from embodiment 2 in that: the pressure gas pipeline 26 further comprises a stop branch which is arranged in parallel with the parallel flow monitoring branch, a third stop valve 219, a second stop valve 211 and a fourth vortex shedding flowmeter 29 are sequentially arranged on the stop branch along the gas flow direction, and the gas outlet end of the pilot pressure regulating valve 210 is communicated with the gas inlet end of the second stop valve 211.
Working process under normal state: the first vortex shedding flowmeter 213, the second vortex shedding flowmeter 214 and the third vortex shedding flowmeter 212 are in a normally open state, the first stop valve 23 is opened, the second stop valve 211, the third stop valve 219 and the fourth stop valve 28 are closed, the pressure value and the gas consumption flow value of the test system are set according to the test pressure and the gas consumption reference value of the tested equipment, the flow monitoring branch with the corresponding range is matched according to the set gas consumption flow value, namely, the first-stage flow monitoring branch, the second-stage flow monitoring branch and the third-stage flow monitoring branch are selected, and the matched parallel flow monitoring branch is opened by opening a pilot type electromagnetic valve matched with the flow monitoring branch; the externally connected compressed air is introduced into a first air inlet main path, roughly adjusts the pressure range through a pilot pressure regulating valve 210, then enters a fully open electric regulating valve 215, enters a parallel flow monitoring branch path matched with flow opening for flow measurement, and then enters an air storage tank 21 through a second air inlet main path for attenuating air flow pulses; when the pressure transmitter 26 displays that the pressure reaches the set value of the system pressure, the fourth pilot-operated solenoid valve 27 is opened, so that the compressed air enters the tested equipment through the first stop valve 23; the output pressure is detected in real time according to the pressure feedback signal of the pressure transmitter, and the pressure is stabilized by adjusting the electric regulating valve 215, so that the pressure output is ensured to be the pressure value set by the system.
Working process in abnormal state: all vortex shedding flowmeters are in a normally open state no matter whether the system is electrified or not. The first state: when the system control power supply is off, the electric control valve 215 and all the pilot-operated solenoid valves are in a closed state. Closing the third stop valve 219, opening the pilot pressure regulating valve 210, the second stop valve 211, the fourth stop valve 28 and the first stop valve 23, and allowing the compressed gas to enter the device under test through the pilot pressure regulating valve 210, the second stop valve 211, the fourth vortex shedding flowmeter 29, the gas holder 21, the fourth stop valve 28 and the first stop valve 23; and a second state: when the electric control valve 215 fails, the electric control valve 215 is in a closed state, and the second and fourth cutoff valves 211 and 28 are closed. The compressed gas enters the tested equipment through the pilot pressure regulating valve 210, the third stop valve 219, the flow monitoring branch matched with the corresponding range, the gas holder 21, the fourth pilot electromagnetic valve 27 and the first stop valve 23. The working gas circuit is a main gas inlet gas circuit in a normal state, and the working gas circuit is a standby gas circuit in an abnormal state.
And setting the pressure and gas consumption ranges of the test system according to the test pressure and gas consumption reference values of the prototype, and intelligently matching the flow monitoring branches by the measurement and control system according to the input value of the gas consumption range of the equipment. Compressed air enters the air storage tank to attenuate air flow pulses through the rough adjustment of the pressure range of the pilot type pressure regulating valve, the fully-opened electric regulating valve and the pilot type electromagnetic valve and the vortex shedding flowmeter which are matched according to the system flow, the stop valve is opened, the pilot type electromagnetic valve is opened when the pressure reaches the system pressure detection value, and compressed air enters the prototype. The system detects the output pressure in real time according to the pressure feedback signal during the test, and the pressure output is ensured at the trigger pressure set by the system by adjusting the stable pressure of the electric regulating valve.
And temperature, pressure and flow signals of the temperature transmitter, the pressure transmitter and the vortex shedding flowmeter are fed back in real time. The gas storage tank is provided with a temperature transmitter for monitoring the gas compression temperature in real time and feeding back a gas temperature signal. The temperature transmitter, the pressure transmitter and the vortex shedding flowmeter adopt standardized interfaces and universal protocols, so that the standardization and the universality of data interfaces are realized, the data implantation capacity is improved, and the generalization degree of a measurement and control system is improved.
Example 4
The present embodiment is different from embodiment 1 in that: the energy absorber 4 comprises four energy absorbers of different energy absorption efficiency classes. The energy absorber consists of a drill rod 41, an upper flange 42, an energy absorber shell 43, an energy absorbing wafer 44, a cushion pad 45, a lower flange 46, a gland 47 and plastic ointment 48.
The energy absorber is mainly used for absorbing impact energy, eliminating redundant vibration of a drill rod and eliminating reflected waves of the drill rod so as to meet the requirement of international standards that the reflected energy of the energy absorber device is less than 20% of the incident energy. The four energy absorbers have the same structure, and the sizes of the energy absorber shell, the energy absorbing wafer and related parts are different according to different energy absorbing efficiencies.
Example 5
The present embodiment is different from embodiment 1 in that: the vertical test bed 3 consists of an air jacking air inlet pipeline 31, a two-position four-way valve 32, a pressure regulating valve 33, a pressure gauge 34, a lifting device 35, a stand column 36, an air jacking 37, a pressing and rotating auxiliary supporting device 38, a calibrating device 39, a base 310, a speed measuring device 311 and a prototype air inlet pipeline 312. A second branch externally connected with compressed air inputs the compressed air into the air ejection inlet pipeline 31; the gas in the second main gas outlet path is input into the prototype gas inlet pipeline 312.
Placing a sample machine 313 on an exposed drill rod 41 of an energy absorber, adjusting a lifting device 35 to a proper position, clamping, pressing and rotating an auxiliary supporting device 38, starting a two-position four-way valve 32 to intake air to a gas cap 37, looking up a table according to the weight of the sample machine and related performance parameters to determine the optimal thrust, adjusting the pressure of a pressure regulating valve 33 to the conversion pressure value of the optimal thrust, and pressing the sample machine 313 by a pressing claw of the gas cap 37. The calibration device 39 is rotated by releasing the compression and slewing auxiliary support device 38 to a position where the compression and slewing auxiliary support device 38 is perpendicular to and coaxial with the energy absorber exposure shank 41. The calibration device 39 is used for coefficient calibration before system test, a drop hammer with a certain weight is arranged in the long pipe, and the energy coefficient and the frequency coefficient are calibrated and calibrated by using a drop hammer method according to the distance between the drop hammer and the striking surface of the energy absorber. The speed measuring device 311 is used for measuring the rotating speed of the prototype under idle running.
Example 6
An impact energy detection method of an intelligent test system for testing impact mechanical products comprises the following steps:
s1, adhering the strain gauge, and after the strain gauge is adhered, performing a calibration test to determine a calibration coefficient, and recording the adhering time of the strain gauge and a connected wire number for future reference. If the calibration is not qualified, the strain gauge should be pasted again.
S2, determining a calibration coefficient B:
drop weight and drop weight height according to a certain mass
h＝2218-l-h0---(1)
In the formula, the free falling height of the h-drop hammer is mm;
l-drop length, mm;
h0-calibrating the distance, mm, from the lower end face of the shank to the upper end face of the shank adapter of the energy-absorbing test drill rod;
2218-calibrate the length of the tube;
the falling hammer is completely converted into kinetic energy, namely impact energy at the moment that the falling hammer impacts a test drill rod from potential energy at a certain height, and the formula is as follows:
E＝mgh----(2)
in which E-drop hammer potential (equal to the impact energy input to the test system), J;
m-drop weight, kg;
g-acceleration of gravity, m/s2；
h-drop height of drop hammer, m;
substituting the falling weight potential energy shown in the formula (2) into the known standard energy E
Automatically processing data by a data processing system, calculating, and finally outputting a calibration coefficient B:
in which a-m is the cross-sectional area of the drill rod2；
Rho-test of density of drill rod material, kg/m3；
c-the propagation speed of the stress wave in the test drill rod, m/s;
b-stress/unit quantization value, i.e. scaling factor, N/(m)21 number);
Δ t-sample time, s;
nj-the digital quantity of the measured voltage corresponding to the jth stress value, in units of 1 digit;
j-number of integration points.
Wherein
And the stress wave data are automatically calculated by the acquisition and conditioning module and the data processing system according to the acquired stress wave data.
S3, measuring and calculating impact energy:
the wave has certain energy when propagating in the drill rod, a certain fixed section in the drill rod has stress P and speed v, and the total energy is Pvddt when acting in dt time
In the formula, A is the sectional area of a drill rod;
r is the duration of the wave;
Complete energy transfer can be achieved in the event that the piston hits the cross-sectional area of the drill rod and the drill rod is sufficiently long. Energy of incident wave
In the formula, Vp-collision velocity of piston
M-piston mass
m-shank fluctuation inertia
According to the impact energy of the rock drilling in the formula (4), a stress course of one point in a drill rod can be captured by adopting a proper transient stress recording means, and then the square product is used for determination.
Two resistance wire strain gauges of 120 ohms are adopted on a drill rod and are oppositely adhered to two sides of the drill rod, and the resistance wire strain gauges are connected in series to be used as one arm of a half bridge to detect longitudinal waves in the drill rod and can also be used as a full bridge to be connected to two opposite arms of a resistance bridge so as to eliminate the influence of bending waves. In order to avoid interference of reflected waves to accurately obtain incident stress waves, the drill rod is long enough, one end of the drill rod is arranged in an energy absorption device, the energy absorption device adopts a long pipe structure, an energy absorption wafer 44 and an energy absorption material are arranged in the energy absorption device, and the energy absorption device simultaneously eliminates redundant vibration of the drill rod so as to improve the testing precision and prolong the service life of the resistance chip.
The working principle of the method conforms to the method recommended by ISO 2787 and GB/T5621, namely a stress wave method. When a sample to be detected works on a vertical test bed, the impact energy of the sample is transmitted to an energy absorption test drill rod adhered with a strain gauge in the form of stress wave, and is transmitted in the drill rod in a one-dimensional wave mode, and the stress wave is called incident wave. When incident waves pass through the cross section of the drill rod attached with the strain gauge, the change of the resistance value of the strain gauge is caused, and the change of the resistance value is in direct proportion to the stress amplitude of the incident waves and the impact energy of impacting the drill rod. By utilizing a dynamic strain measurement technology, a test system captures and records the transient stress course of one point in a test drill rod, namely the position where a strain gauge is attached, under the control of a built-in acquisition and conditioning module of a measurement and control host and a data processing system, and then at least 30 points are integrated by using enough integration points to obtain impact energy.
In the test system, the incident stress wave energy function is technically processed, namely, the stress value in the function is converted into a voltage quantity, the voltage quantity is converted into a digital quantity through A/D (analog/digital) conversion, the intermediate process of calculation is omitted, and finally, the mathematical model of impact energy detection is as follows:
in the formula, E-impact energy, J;
a-test the cross-sectional area of drill rod, m2；
Rho-test of density of drill rod material, kg/m3；
c-the propagation speed of the stress wave in the test drill rod, m/s;
b-stress/unit quantization value, i.e. scaling factor, N/(m)21 number);
Δ t-sample time, s;
nj-the digital quantity of the measured voltage corresponding to the jth stress value, in units of 1 digit;
j-number of integration points.
In the formula, after the test drill rod material is determined, the values of a, rho and c are also determined, namely constants; when the sampling time is set, delta t is also constant; when the calibration factor B is determined, the impact energy E is only compared with n representing the impact stressj 2In connection with this, the test system automatically collects the data and can calculate the impact energy E.
When the test system detects the impact energy of the sample, the system automatically collects the times of impact stress pulses generated by the impact test drill rod of the sample piston within a certain time range by the computer under the control of a computer test program, thereby calculating the impact frequency of the sample by the program. The frequency is only used as reference data of the detected sample, and the impact frequency specified by the product standard is measured by the detected sample under the actual working condition.
Example 7
This embodiment is different from embodiment 6 in that: the method for pasting the strain gauge comprises the following steps:
(1) taking two strain gauges, checking whether the strain gauges are intact or not, and respectively measuring resistance values by using a universal meter to ensure that the resistance values are 120 ohms;
(2) the patch positions are positioned on two symmetrical side surfaces of the drill rod at a position which is about 300mm away from the upper end surface of the drill rod shank of the energy absorption test drill rod. Before the surface mounting, firstly, polishing the surface of a drill rod surface mounting piece by using sand paper, and cleaning the surface (at least three times) of the surface mounting piece and the surface around the surface mounting piece by using acetone or absolute ethyl alcohol;
(3) sticking the front surface (the surface without adhesive) of each strain gauge on transparent adhesive tape, coating H-611 adhesive on the cleaned drill rod part uniformly, sticking the adhesive tape and the strain gauge on the drill rod in a preset direction and position, immediately bonding the strain gauge with the drill rod, carefully pressing one end of the strain gauge with one thumb, and pressing the other thumb from one end to the other end with proper force for several times so as to extrude bubbles and stick the strain gauge firmly;
(4) after pasting, connecting one end of two strain gauges in series, reserving two leads, and checking whether the group of strain gauges are connected or not by using a universal meter and whether the resistance value is 240 ohms or not;
(5) after 10 minutes, slightly tearing off the adhesive tape (pressing the lead part), and naturally drying for more than half an hour (the time is determined according to the solidification time of the glue);
(6) and (5) binding. Before binding up, insulation treatment between the drill rod and the lead is carried out, generally, two to three layers of insulating adhesive tape paper are laid on the lower portion of the lead of the strain gauge, a layer of insulating black adhesive tape is laid on the lower portion of the lead joint, and then the strain gauge and the lead joint are tightly wrapped by transparent adhesive tape. The principle of lead wire treatment is that the lead wire is shortest, the welding spot is smallest and the binding is firm;
(7) using a universal meter to check whether the strain gauge is connected or not, whether the resistance value is 240 ohms or not and whether the grounding phenomenon exists or not;
(8) and welding the lead wire of the strain gauge with the signal wire connected with the outside.
Finally, the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting, and other modifications or equivalent substitutions made by the technical solutions of the present invention by those of ordinary skill in the art should be covered within the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solutions of the present invention.
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