A ceramic ball impact fatigue life tester and testing method

Abstract

This invention discloses a ceramic ball impact fatigue life testing machine and method, comprising a shell, a lifting and conveying device, and a power supply system; an inlet and an outlet on the shell, the outlet being located below the inlet; a collision plate between the inlet and outlet; the lifting and conveying device having a conveyor belt and a lifting bucket disposed on the conveyor belt; an inlet and a delivery inlet on the lifting and conveying device, the inlet being located below the delivery inlet; a first conveying component, which receives ceramic balls from the outlet and transfers them to the inlet, the ceramic balls entering the lifting bucket through the inlet; and a second conveying component extending into the delivery inlet, which receives ceramic balls from the delivery bucket and transports them to the inlet. This invention promotes the development of the ceramic ball industry towards high strength, high wear resistance, and high impact toughness, and drives the common progress of the ceramic ball industry and the cement industry.

Description

Technical Field

[0001] This invention relates to the field of impact resistance of ceramic balls, and more particularly to a ceramic ball impact fatigue life testing machine and testing method. Background Technology

[0002] Impact fatigue life is an important indicator for wear-resistant alumina ceramic balls used in cement grinding systems.

[0003] Currently, there is no equipment to test the impact fatigue life of ceramic balls. This acceptance test for ceramic ball products is carried out manually, that is, the ceramic ball is dropped from a height of 6 meters or a certain height and thrown into a steel plate. After a certain number of times, it is observed whether it is damaged.

[0004] The following problems exist in this test process: First, it is difficult to select a test site, which is generally not feasible in a laboratory; second, the human factor has a large impact on the test process; third, the test consumes a lot of manpower, requiring at least two people to carry out the test, which involves repeatedly transporting the ball to a certain height and then dropping it thousands of times, making it difficult to ultimately measure the impact fatigue life of the ceramic ball. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a ceramic ball impact fatigue life testing machine and testing method.

[0006] According to one aspect of the present invention, a ceramic ball impact fatigue life testing machine is provided, characterized in that it includes...

[0007] Housing, lifting and transmission device and power supply system;

[0008] An inlet and an outlet are provided on the housing, with the outlet located below the inlet;

[0009] A collision plate is installed between the inlet and outlet of the ball;

[0010] The lifting and conveying device is equipped with a conveyor belt and a lifting bucket disposed on the conveyor belt. The higher end of the conveyor belt is close to the ball inlet, and the lower end of the conveyor belt is close to the ball outlet.

[0011] The ball inlet and ball delivery outlet are provided at the ball inlet of the lifting and conveying device, with the ball inlet located below the ball delivery outlet;

[0012] The first conveying component is used to receive ceramic balls from the ball outlet and transfer them to the ball inlet, through which the ceramic balls enter the lifting bucket.

[0013] The second conveying component extends into the ball inlet and its function is to receive the ceramic ball from the lifting bucket and transport the ceramic ball to the ball inlet.

[0014] Furthermore, the lifting bucket includes a base plate connected to the conveyor belt;

[0015] Side plates are arranged opposite each other on the base plate, one end of the side plate is connected by a ball receiving plate, and the other end of the side plate is connected by a ball guiding plate;

[0016] The base plate, side plates, ball receiving plate, and ball guide plate form a ball storage space. The angle between the ball receiving plate and the base plate is 60-85°, and the angle between the ball guide plate and the base plate is not less than 140°.

[0017] Furthermore, the ball receiving plate and ball guiding plate of the adjacent lifting buckets are in contact.

[0018] Furthermore, the ball outlet is provided with a hollow, closed disc, inside which is a turntable. The turntable is controlled by a motor to rotate at a constant speed, and the turntable is provided with several acceleration channels.

[0019] The ceramic ball outlet is located directly above the collision plate on the disk. When the ceramic ball reaches the ceramic ball outlet, the direction of its linear velocity and acceleration is vertically downward.

[0020] Furthermore, a screening device is provided between the first conveying component and the ball inlet. The screening device includes a transmission channel, which includes a sieve plate composed of several connecting rods. One end of the sieve plate is connected to the ball inlet area, which is used to receive ceramic balls from the first conveying component. The other end of the sieve plate is connected to the ball outlet area, which is connected to the ball inlet.

[0021] Furthermore, the spacing between the connecting rods can be adjusted according to the particle size of the ceramic balls.

[0022] Furthermore, the first conveying component includes a lower conveyor belt and a lower variable frequency motor. The ceramic ball lands in the middle of the lower conveyor belt, and the lower variable frequency motor can control the lower conveyor belt to convey the ceramic ball in the forward or reverse direction.

[0023] Furthermore, it also includes a control system, wherein the lifting and transmission device, the first transmission component, and the second transmission component are signal-connected to the control system.

[0024] Furthermore, it also includes a control system, wherein the lifting and transmission device, the first transmission component, the second transmission component, the motor, and the control system are signal connected.

[0025] Furthermore, the control system is equipped with a touch screen control panel, frequency converter, encoder, PLC host, expansion unit, analog input unit, transformer, and filter, which can directly program input parameters to control the ceramic ball transmission speed and / or ball-shooting speed and / or impact speed.

[0026] According to one aspect of the present invention, a method for testing the impact fatigue life of ceramic balls is provided, comprising the following steps:

[0027] Several ceramic balls were randomly selected and inserted into the shell through the inlet. The ceramic balls were controlled to fall vertically toward the collision plate at a speed of 8.90±0.05m / s, with a falling height difference of 3-5 meters.

[0028] The first conveying component sends the impacted ceramic ball into the lifting and conveying device;

[0029] The lifting and conveying device transfers the impacted ceramic ball to the ball inlet for another impact, and repeats this process until the preset conditions are met. The number of impacts at the time of each broken ceramic ball is counted to calculate the average impact fatigue life of the ceramic ball.

[0030] Compared with the prior art, the beneficial effects of this application are as follows:

[0031] 1. This invention solves the problem of selecting a test site and eliminates the uncertainties in manual testing. This equipment can save time and effort and effectively measure the impact fatigue life of ceramic balls, replacing manual testing of thousands of times to determine the effective fatigue life of ceramic balls, guiding customers in production and use, promoting the development of the ceramic ball industry towards high strength, high wear resistance, and high impact toughness, and driving the common progress of the ceramic ball industry and the cement industry.

[0032] 2. The present invention comprises a bottom plate, side plates, a ball receiving plate, and a ball guiding plate forming a ball storage space. The angle between the ball receiving plate and the bottom plate is 60-85°, and the angle between the ball guiding plate and the bottom plate is not less than 140°. The 60-85° angle ensures that the ceramic ball is caught smoothly when it falls into the lifting bucket, and the 140° angle at the top ensures that the ceramic ball can be poured out smoothly when the bucket is flipped. The bottom of the two lifting buckets is also gapped, which ensures that the ceramic balls will not be squeezed or collided during the flipping.

[0033] 3. The turntable of this invention is equipped with several acceleration channels, which can make the ceramic ball fall at any speed when it is thrown from any height.

[0034] 4. The method for testing the impact fatigue life of ceramic balls in this invention simulates the most severe impact process of ceramic balls in a ball mill, that is, the ceramic balls are continuously dropped from a certain height and repeatedly hit the impact plate. The number of impact fatigue failures (ceramic ball breakage) reflects the impact fatigue life of the ceramic balls under this condition. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of the present invention. Figure 1 .

[0036] Figure 2 This is a schematic diagram of the control system module of the present invention.

[0037] Figure 3 This is a schematic diagram of the control system of the present invention.

[0038] Figure 4 This is a schematic diagram of the structure of the housing of the present invention.

[0039] Figure 5 This is a schematic diagram of the structure of the first transmission component of the present invention.

[0040] Figure 6 This is a schematic diagram of the screening device of the present invention.

[0041] Figure 7 This is a schematic diagram of the structure of the transmission device of the present invention.

[0042] Figure 8 A schematic diagram of the bucket structure.

[0043] The following figures show the following labels: 1-Control system; 2-House; 21-Collision plate; 22-Disc; 23-Turntable; 24-Acceleration channel; 25-Outlet; 26-Motor; 27-Inlet; 3-Outlet; 4-First conveying assembly; 5-Screening device; 51-Screening plate; 52-Inlet area; 53-Outlet area; 6-Lifting and conveying device; 7-Second conveying assembly; 8-Photoelectric counter; 9-Lifting bucket; 91-Side plate; 92-Ball receiving plate; 93-Ball guide plate; 10-Ceramic ball. Detailed Implementation

[0044] This embodiment provides a ceramic ball impact fatigue life testing machine, including: a shell 2, a lifting and conveying device 6, and a power supply system;

[0045] A ball inlet 27 and a ball outlet 3 are provided on the housing 2, with the ball outlet 3 located below the ball inlet;

[0046] A collision plate 21 is provided between the inlet and outlet 3. The collision plate 21 is a metal disc 22 with a diameter of 200 mm and a thickness of 20 mm, which is fixed between the inlet and outlet 3.

[0047] The lifting and conveying device 6 is equipped with a conveyor belt and a lifting bucket 9 disposed on the conveyor belt. The conveyor belt is driven by a lifting motor. The higher end of the conveyor belt is close to the ball inlet, and the lower end of the conveyor belt is close to the ball outlet 3.

[0048] The ball inlet and ball delivery outlet are located below the ball delivery outlet of the lifting and conveying device 6. The ball outlet 3 is provided with a hollow, closed disc 22, and a turntable 23 is provided inside the disc 22. The turntable 23 is controlled by a motor 26 to rotate at a constant speed. The turntable 23 is provided with several acceleration channels 24. The ceramic ball is fed into the center of the acceleration turntable 23. The turntable 23 centrifugally accelerates the relatively stationary ceramic ball with a constant angular velocity ω, and finally throws the ceramic ball out from the outlet 25 at a constant linear velocity. The advantages of this design are that the acceleration of the ceramic ball starts from 0, eliminating the problem of collision between the ceramic ball and the turntable 23 during acceleration (if the ceramic ball collides directly with the turntable 23 after entering the acceleration system, it may not be able to accelerate). The speed of the turntable 23 is controllable. The ceramic ball is input from the middle of the acceleration turntable 23. Through the acceleration of the turntable 23, the ceramic ball is accelerated from a standstill. The entire process is automated, and the output speed of the ceramic ball can be arbitrarily controlled. The speed of the thrown ceramic ball is controllable, the running time between each acceleration channel 24 is controllable, and the throwing direction of the ceramic ball is consistent and controllable. The turntable 23 is controlled to rotate at a constant speed in a circular motion by a variable frequency motor 26. A collision plate 21 is set below the turntable 23 in the centrifugal direction. The ceramic ball outlet 25 is set on the disc 22 directly above the collision plate 21. When the ceramic ball reaches the ceramic ball outlet 25, the direction of its linear velocity and acceleration is vertically downward. The collision plate 21 is exactly located at the position where the ceramic ball flies out along the tangent of the outlet 25, which can achieve a head-on collision.

[0049] The first conveying component 4, equipped with a lower conveyor belt and a lower variable frequency motor, serves to receive ceramic balls from the ball outlet 3 and transfer them to the ball inlet. The first conveying component 4 can rotate in both forward and reverse directions. Optionally, a collection trough is provided at the end of the first conveying component 4 furthest from the lifting device. Forward rotation of the conveyor belt sends overflowing ceramic balls into the screening device 5 for circulation, while reverse rotation sends overflowing ceramic balls into the collection trough and stops the test. Optionally, the first conveying component includes a lower conveyor belt and a lower variable frequency motor. The ceramic balls land in the middle of the lower conveyor belt, and the lower variable frequency motor controls the lower conveyor belt to transport the ceramic balls in either the forward or reverse direction. Optionally, a recycling hopper is provided at the other end of the lower conveyor belt to transport the ceramic balls 10 in the reverse direction to the recycling hopper. Figure 6As shown, to prevent the ceramic balls from scattering, an outer shell can be used to cover the lower conveyor belt. The ceramic balls enter the lifting bucket 9 through the ball inlet. Specifically, the lifting bucket 9 includes a base plate connected to the conveyor belt; side plates 91 are arranged opposite each other on the base plate, one end of the side plate 91 is connected by a ball receiving plate 92, and the other end of the side plate 91 is connected by a ball guide plate 93; the base plate, side plates 91, ball receiving plate 92, and ball guide plate 93 form a ball storage space. The angle between the ball receiving plate 92 and the base plate is 60-85°, and the angle between the ball guide plate 93 and the base plate is not less than 140°. The ball receiving plates 92 and ball guide plates 93 of adjacent lifting buckets 9 are in contact, and there is a gap at the bottom between the two buckets to ensure that the ceramic balls will not be squeezed or collided during flipping. Several lifting buckets 9 are evenly spaced. Installed on a conveyor belt, the system circulates under the drive of a variable frequency motor 26. After multiple tests, the angle of the lifting bucket 9 is determined to be such that it catches the ceramic balls at the bottom, transports them to the top, and then flips to empty them. As an optional feature, a screening device 5 is provided between the first conveying component 4 and the ball inlet. The screening device 5 includes a conveying channel, which comprises a sieve plate 51 composed of several connecting rods (such as connecting rods). The spacing between the connecting rods can be adjusted according to the particle size of the ceramic balls. One end of the sieve plate 51 is connected to a ball inlet area 52, which receives the ceramic balls from the first conveying component 4. The other end of the sieve plate 51 is connected to a ball outlet area 53, which communicates with the ball inlet. As an optional feature, the ball outlet area 53 is equipped with an arc-shaped ball feeding plate to prevent the ceramic balls from accumulating in the ball outlet area 53.

[0050] The second conveying component 7 consists of an upper conveyor belt and an upper variable frequency motor. The conveyor belt extends into the ball feeding port and its function is to receive the ceramic balls from the lifting bucket 9 and transport the ceramic balls to the ball feeding port. The ceramic balls can be circulated into the shell 2 to achieve automatic continuous ball feeding. The acceleration of the ceramic balls starts from 0 and completes the impact fatigue life test of the ceramic balls. As an optional solution, the second conveying component is equipped with a photoelectric counter 8, which can be a JDM11-6H type photoelectric counter, to record the number of times the balls are impacted.

[0051] It also includes a control system 1. The lifting and transmission device 6, the first transmission component 4, the second transmission component 7, and the motor 26 are signal-connected to the control system 1. Specifically, the control system 1 is equipped with a touch screen control panel, a frequency converter, an encoder, a PLC host, an expansion unit, an analog input unit, a transformer, and a filter. The motor 26, the lifting motor, the upper frequency converter motor, and the lower frequency converter motor are collectively referred to as the mechanical and power unit. Parameters can be directly programmed and input to control the mechanical and power unit, including the ceramic ball transmission speed and / or the ball-sinking speed and / or the impact speed. The speed at which the ceramic ball is thrown out of the ceramic ball outlet 25 can be changed by changing the rotation speed of the turntable 23. In this embodiment... A method for testing the impact fatigue life of ceramic balls is provided, comprising the following steps: randomly selecting several ceramic balls and loading them into the shell 2 through the ball inlet, and controlling the ceramic balls to fall vertically towards the impact plate 21 at a speed of 8.90±0.05m / s, with a falling height difference of 3-5 meters. In this embodiment, the falling height is selected as 4 meters. The impact plate 21 is made of high-strength medium carbon steel with a hardness of not less than HRC60. The specific acceleration method is as follows: the ceramic balls are sent into the center of the acceleration turntable 23 through the ball inlet. The turntable 23 centrifugally accelerates the relatively stationary ceramic balls at a constant angular velocity ω, and finally throws the ceramic balls out from the outlet 25 at a constant linear velocity, impacting the impact plate 21.

[0052] The first conveying component 4 sends the impacted ceramic ball into the lifting and conveying device 6. The lifting and conveying device transfers the impacted ceramic ball to the ball inlet for another impact. This process is repeated until the preset conditions are met. The number of impacts when each broken ceramic ball breaks is counted to calculate the average impact fatigue life of the ceramic ball.

[0053] This embodiment provides a test method for using the above-mentioned ceramic ball impact fatigue life tester, including the following steps:

[0054] Step 1: Randomly select several ceramic balls and insert them into the shell through the inlet. Control the ceramic balls to fall vertically towards the collision plate at a speed of 8.90±0.05m / s, with a falling height difference of 3-5 meters.

[0055] Step 2: The first conveying component sends the impacted ceramic ball into the lifting and conveying device;

[0056] Step 3: The lifting and conveying device transfers the impacted ceramic ball to the inlet for another impact, repeating this process until the preset conditions are met. The number of impacts at the time of each broken ceramic ball is counted, and the average impact fatigue life of the ceramic ball is calculated. The impact fatigue life of the ceramic ball is determined according to formula (C-1):

[0057]

[0058] In formula (C-1): N - average impact fatigue life of ceramic balls / cycles; N i- Impact fatigue life of the i-th ceramic ball / cycles.

[0059] This implementation uses ceramic balls as an example to provide a specific experimental procedure, which includes the following steps:

[0060] Step 1: Randomly select a number of ceramic balls (10 in this example) that meet the appearance quality requirements and load them into the ball hopper;

[0061] Step 2: Turn on the power switch, activate the belt reversal button of the first conveyor component, and clear debris from the conveyor channel of the testing machine;

[0062] Step 3: Adjust the motor parameters of the turntable so that the ball-spinning linear speed is 8.90±0.05m / s;

[0063] Step 4: Press the start button to start the equipment and send the balls into the shell. When the number of broken ceramic balls reaches the set value, the preset condition is met. In this embodiment, the impact is stopped when the number of broken balls reaches 3. The cumulative number of collisions Ni when the first 3 test balls fail is recorded. The time point when each ceramic ball breaks can be automatically identified or manually counted. Even if manual counting is used, the number of workers and the amount of labor are reduced compared with the prior art.

[0064] Step 5: After the experiment is completed, retrieve the test ball from the experimental channel and turn off the power;

[0065] Step 6: Calculation of Results. The impact fatigue life of the ceramic ball is determined according to formula (C-1):

[0066]

[0067] Because each ceramic ball undergoes tens of thousands of collisions, I only selected the failure counts of 3 out of 10 balls to evaluate fatigue life. For example, the first ball failed after 135,000 collisions, the second after 152,000, and the third after 181,000. Therefore, the fatigue life of this batch of ceramic balls is:

[0068] 7*135000 / 270+7*152000 / 216+18100 / 24=3500+4926+7542=15968 times

[0069] The principle is as follows: because the counter records the number of balls in an accumulated input acceleration system; the number of times the first ball fails is recorded as N1, and the actual number of collisions of the first ball is N1 / 10;

[0070] The number of times the second ball failed was recorded as N2, and the actual number of collisions of the second ball was (N2-N1) / 9+N1 / 10;

[0071] The number of times the third ball failed was recorded as N3. The actual number of collisions of the third ball was (N3-N2) / 8+(N2-N1) / 9+N1 / 10.

[0072] Therefore, the average number of failures for the 3 balls, N, is: [N1 / 10 + (N2 - N1) / 9 + N1 / 10 + (N3 - N2) / 8 + (N2 - N1) / 9 + N1 / 10] / 3

[0073] After simplification When processing data, the decimal part is rounded to the integer value according to the GB / T8170 numerical rounding rules.

[0074] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A ceramic ball impact fatigue life testing machine, characterized in that, It includes a housing, a lifting and conveying device and a power supply system, wherein the lifting and conveying device is provided with a conveyor belt and lifting buckets disposed on the conveyor belt; An inlet and an outlet are provided on the housing, with the outlet located below the inlet; A collision plate is installed between the inlet and outlet of the ball; The ball inlet and ball outlet of the lifting and conveying device are provided; The first conveying component is used to receive ceramic balls from the ball outlet and transfer them to the ball inlet, through which the ceramic balls enter the lifting bucket. The second conveying component has one end extending into the ball inlet, and its function is to receive the ceramic ball from the lifting bucket and transport the ceramic ball to the ball inlet. The ball outlet is provided with a hollow, closed disc, and a turntable is provided inside the disc. The turntable rotates at a constant speed under the control of a motor, and the turntable is provided with several acceleration channels. The ceramic ball is fed into the center of the acceleration turntable. The turntable accelerates the relatively stationary ceramic ball with a constant angular velocity ω, and finally throws the ceramic ball out of the outlet with a constant linear velocity. The ceramic ball outlet is located directly above the collision plate on the disk. When the ceramic ball reaches the ceramic ball outlet, the direction of its linear velocity and acceleration is vertically downward. The lifting and conveying device transfers the impacted ceramic ball to the inlet for another impact, and repeats this process until a preset condition is reached. The number of impacts when each broken ceramic ball breaks is counted, and the average impact fatigue life of the ceramic ball is calculated. The number of broken ceramic balls is a set value. The lifting bucket includes: a base plate connected to the conveyor belt, and side plates are disposed opposite to each other on the base plate; One end of the side plate is connected via a ball receiving plate, and the other end of the side plate is connected via a ball guiding plate; The base plate, side plates, ball receiving plate, and ball guide plate form a ball storage space. The angle between the ball receiving plate and the base plate is 60-85°, and the angle between the ball guide plate and the base plate is not less than 140°.

2. The ceramic ball impact fatigue life testing machine according to claim 1, characterized in that, The ball receiving plate and ball guiding plate of the adjacent lifting buckets are in contact.

3. The ceramic ball impact fatigue life testing machine according to claim 1, characterized in that, A screening device is provided between the first conveying component and the ball inlet. The screening device includes a transmission channel, which includes a sieve plate composed of several connecting rods. One end of the sieve plate is connected to the ball inlet area, which is used to receive ceramic balls from the first conveying component. The other end of the sieve plate is connected to the ball outlet area, which is used to send ceramic balls into the ball inlet.

4. The ceramic ball impact fatigue life testing machine according to claim 3, characterized in that, The spacing between the connecting rods can be adjusted according to the particle size of the ceramic balls.

5. The ceramic ball impact fatigue life testing machine according to claim 1, characterized in that, The first conveying component includes a lower conveyor belt and a lower variable frequency motor. The ceramic ball lands in the middle of the lower conveyor belt, and the lower variable frequency motor can control the lower conveyor belt to convey the ceramic ball in the forward or reverse direction.

6. The ceramic ball impact fatigue life testing machine according to claim 1, characterized in that, It also includes a control system, wherein the lifting and transmission device, the first transmission component, and the second transmission component are signal-connected to the control system.

7. The ceramic ball impact fatigue life testing machine according to claim 6, characterized in that, The control system is equipped with a touch screen control panel, frequency converter, encoder, PLC host, expansion unit, analog input unit, transformer, and filter. It can directly program and input parameters to control the transmission speed and / or ball-shooting speed and / or impact speed of the ceramic ball.

8. A method for testing the impact fatigue life of ceramic balls, wherein the test is conducted using the ceramic ball impact fatigue life testing machine according to any one of claims 1-7, characterized in that, Includes the following steps, Several ceramic balls were randomly selected and inserted into the shell through the inlet. The ceramic balls were controlled to fall vertically toward the collision plate at a speed of 8.90±0.05m / s, with a falling height difference of 3-5 meters. The first conveying component sends the impacted ceramic ball into the lifting and conveying device; The lifting and conveying device transfers the impacted ceramic ball to the ball inlet for another impact, and repeats this process until the preset conditions are met. The number of impacts at the time of each broken ceramic ball is counted to calculate the average impact fatigue life of the ceramic ball.

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