Preparation method and control method of shield inserted hob

Abstract

The invention relates to the technical field of hobs for shield tunneling machines, and particularly discloses a preparation method and a control method of a shield inserted hob, and the method comprises the following steps: marking a hob tooth preparation powder material as preparation powder, and monitoring and controlling the preprocessing state of the preparation powder; according to the method, the cold pressing state of the prepared powder is monitored, the quality, the temperature and the moisture content of the prepared powder in the cold pressing process are obtained, the sintering state of a blank is monitored, the density and the porosity of the blank in the sintering process are obtained, and the processing quality of hob teeth is evaluated in the processing process of the prepared powder. According to the method, the machining state of the hob material is evaluated, machining control parameters are adjusted in real time, the machining effect is improved, meanwhile, through quality evaluation in the machining process, risk points possibly influencing the machining quality and the production efficiency are found in time, and the stability and reliability of equipment are improved.

Description

Technical Field

[0001] The invention relates to the technical field of shield machine hobs, in particular to a preparation method of a shield machine insert cutter and a control method thereof. Background Art

[0002] In recent years, with the increasing number of urban underground construction, shield construction has been widely used in urban underground construction due to its high construction efficiency and small impact on the surrounding environment. Due to the structure of the shield machine and the construction method of the shield, the cutter is used in the hard rock excavation process. When the shield machine is excavating in a composite stratum with uneven soft and hard surfaces, frequent problems such as sharp wear of the cutter, tooth collapse and eccentric wear will lead to reduced excavation efficiency. In severe cases, it may even cause the shield machine to be unable to excavate and be forced to shut down, directly affecting the progress and safety of the project. Therefore, it is necessary to provide a preparation method and control method of a shield toothed cutter to improve the wear resistance and impact resistance of the shield cutter.

[0003] For example, the invention patent with publication number CN110468406B discloses a wear-resistant coating, a preparation method thereof, a shield cutter ring, a shield cutter, and a shield machine. The wear-resistant coating comprises at least two layers of substantially identical brazing filler metal coatings; the brazing filler metal coatings are prepared from the following components, calculated by weight: 3-10 parts diamond micropowder, 2-6 parts alcohol solvent, 1-5 parts sodium fluoride, and 81-93 parts nickel-based brazing filler metal. The wear-resistant coating provided by the present invention utilizes multiple passes of substantially identical, thinner coatings to form a gradient transition coating. This alleviates the thermal stress problem encountered when preparing thicker coatings by surfacing welding, inhibits crack initiation and propagation to a certain extent, and helps to improve the uniform distribution of the hard phase diamond micropowder. The invention has the advantages of minimal thermal damage, uniform hard phase distribution, and resistance to shedding. The shield cutter provided in this application has a cutter ring surface coated with the wear-resistant coating, effectively improving the wear resistance of the cutter ring and extending its service life.

[0004] For example, the invention patent with announcement number CN111020445B discloses a wear-resistant alloy powder comprising a first component and a second component, wherein the first component comprises the following raw material components in weight percentage: 0.8-2.0% carbon, 3.0-7.0% chromium, 0.1-0.6% titanium, 6-10% tungsten, 0.1-0.6% vanadium, with the balance being iron and unavoidable trace impurities; the second component is silicon carbide whiskers; the first component accounts for 90-98% of the total mass of the wear-resistant alloy powder, with the balance being the second component. This application can reduce the stress of the cladding layer, reduce cracking, and effectively reduce the crack sensitivity of the coating, producing a dense, crack-free wear-resistant coating. This not only improves the coating preparation efficiency, but also reduces the heat-affected zone, and can produce wear-resistant shield cutter rings.

[0005] Based on the above scheme, it is found that there are still some deficiencies in the preparation of roller cutters for shield machines, which are specifically reflected in the following aspects: (1) There is currently a lack of methods to monitor the material status during the preparation of roller cutters, and it is impossible to adjust the processing conditions in real time according to the material status, which may cause large fluctuations in the quality of the processed roller cutters and affect the normal operation of the equipment in the later stage;

[0006] (2) Currently, there is a lack of effective methods to evaluate the quality of hobs. Hob quality will directly affect the quality of gear processing. The lack of effective hob quality evaluation methods makes it difficult to detect potential quality problems of hobs in a timely manner, affecting the transmission accuracy and service life of gears and increasing the maintenance cost of equipment. Summary of the Invention

[0007] In view of the deficiencies in the prior art, the present invention provides a method for preparing a shield insert cutter and a control method thereof, which can effectively solve the problems involved in the above-mentioned background technology.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions: The first aspect of the present invention provides a preparation control method for a shield cutter hob, comprising: marking the powder material for preparing the hob teeth as preparation powder, and monitoring and controlling the pre-processing state of the preparation powder.

[0009] During the powder preparation process, the machining quality of the hob cutter teeth is evaluated.

[0010] As a further method, the pre-processing status of the prepared powder is monitored, and specific monitoring dimensions include: monitoring and control of the preparation powder drying pretreatment, monitoring and control of the preparation powder cold pressing treatment, and monitoring and control of the blank sintering treatment.

[0011] As a further method, the powder preparation drying pretreatment monitoring includes the following specific processes: collecting the moisture content and mass of the powder preparation, and obtaining the material properties of the powder preparation from the hob manufacturing database, including melting point and thermal conductivity, and comprehensively calculating the characteristic values ​​of the powder preparation to evaluate the heat resistance of the powder preparation and the required degree of drying, and serving as a basis for adjusting the oven working temperature and working time.

[0012] The oven's operating temperature and operating time are combined to generate a label, which is marked as the oven working label. The prepared powder characteristic value is matched with the oven working label corresponding to each prepared powder characteristic value interval stored in the hob manufacturing database to obtain the oven working label corresponding to the prepared powder. This label is recorded as the designated label, and the oven is adjusted and controlled according to the oven's operating temperature and operating time in the designated label.

[0013] As a further method, the powder preparation cold pressing process monitoring and control specifically includes the following steps: obtaining initial working parameters of the cold press.

[0014] Monitor the status of powder preparation during cold pressing, calculate the abnormal evaluation index of powder preparation during cold pressing, which is used to evaluate the cold pressing effect of powder preparation and serve as the basis for adjusting and controlling the working parameters of the cold press.

[0015] The threshold value of the abnormal cold pressing state assessment index of the prepared powder is obtained from the hob manufacturing database, and the abnormal cold pressing state assessment index of the prepared powder is compared with the threshold value of the abnormal cold pressing state assessment index of the prepared powder. If the abnormal cold pressing state assessment index of the prepared powder is higher than the threshold value of the abnormal cold pressing state assessment index of the prepared powder, a feedback warning is issued, and the linear curve between the abnormal cold pressing state assessment index and the reference execution pressing speed, reference execution control temperature and reference execution control pressure of the cold press stored in the hob manufacturing database is extracted. The reference execution pressing speed, reference execution control temperature and reference execution control pressure of the cold press corresponding to the prepared powder are located and extracted in turn, and marked as the target execution pressing speed, target execution control temperature and target execution control pressure of the cold press for adjustment and control.

[0016] As a further method, the blank sintering process is monitored and controlled, and the specific process is: obtaining the initial working parameters of the sintering furnace.

[0017] The state of the blank during sintering is monitored, and the abnormal evaluation index of the blank sintering state is calculated to evaluate the sintering effect of the blank and serve as the basis for adjusting and controlling the working parameters of the sintering furnace.

[0018] The blank sintering state abnormality assessment index threshold is obtained from the hob manufacturing database, and the blank sintering state abnormality assessment index is compared with the blank sintering state abnormality assessment index threshold. If the blank sintering state abnormality assessment index is higher than the blank sintering state abnormality assessment index threshold, a feedback warning is issued, and the linear curve between the sintering state abnormality assessment index stored in the hob manufacturing database and the sintering furnace reference execution sintering temperature and the sintering furnace reference execution furnace pressure is extracted. The sintering furnace reference execution sintering temperature and the sintering furnace reference execution furnace pressure corresponding to the blank are located and extracted in turn, and marked as the target execution sintering temperature and the target execution furnace pressure of the sintering furnace for adjustment and control.

[0019] As a further method, the processing quality of the hob cutter teeth is evaluated, and the specific analysis process is: obtaining the blank quality evaluation index and the alloy block quality evaluation index, wherein the blank quality evaluation index represents the data obtained by quantitatively evaluating the quality of the blank after cold pressing, which is used to reflect the cold pressing effect during the tooth manufacturing process, and the alloy block quality evaluation index represents the data obtained by quantitatively evaluating the quality of the alloy block after sintering, which is used to reflect the sintering effect during the tooth manufacturing process.

[0020] Calculate the tooth quality evaluation index, and its calculation expression is: Where φ represents the cutter tooth quality evaluation index, δ1 and δ2 represent the blank quality evaluation index and alloy block quality evaluation index, respectively, and υ1 and υ2 represent the cutter tooth quality influence weight factors corresponding to the set blank quality evaluation index and alloy block quality evaluation index, respectively.

[0021] As a further method, the blank quality evaluation index has the following specific analysis process: extracting the critical moisture content of the cold-pressed blank and the estimated quality range of the cold-pressed blank from the hob manufacturing database, extracting the middle value of the estimated quality range of the cold-pressed blank as a reference to the cold-pressed quality standard value, and at the same time collecting the quality and moisture content of the blank after cold pressing, and comprehensively calculating the blank quality evaluation index for evaluating the quality of the blank after cold pressing.

[0022] As a further method, the alloy block quality evaluation index has a specific analysis process of obtaining the reference standard mass and reference standard density of the alloy block from the hob manufacturing database, and at the same time collecting the mass and density of the sintered alloy block, and comprehensively calculating the alloy block quality evaluation index for evaluating the quality of the sintered alloy block.

[0023] The second aspect of the present invention provides a method for preparing a shield insert hob, comprising: obtaining a WC-Co-Ni-Re composite powder, uniformly mixing the composite powder with 2.5wt.% paraffin wax, drying the mixture in a 60°C oven for 1 hour, and then sieving the mixture.

[0024] Using a unidirectional pressure cold press at a pressing pressure of 6MPa, the mass of the blank obtained is 380-400g, and the cold pressing needs to be maintained for 10-15s.

[0025] The alloy is formed in a pressure sintering furnace or a vacuum sintering furnace, wherein the sintering temperature is controlled at about 1400°C, the sintering holding time is 1 hour, the pressure in the pressure furnace is 2MPa, and after sintering, it is polished to the tooth shape described below.

[0026] The working temperature and working time of the oven, the pressing speed, temperature and pressing pressure of the cold press, and the sintering temperature and furnace pressure of the pressure sintering furnace or vacuum sintering furnace are all regulated by the preparation control method of the shield insert cutter.

[0027] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: (1) The present invention provides a preparation method and control method of a shield cutter hob, monitors the cold pressing state and sintering state of the paint cutter material, obtains the density and porosity of the blank during the sintering process, and evaluates the processing state of the hob material, thereby adjusting the processing control parameters in real time to improve the processing effect. At the same time, through quality evaluation during the processing process, risk points that may affect the processing quality and production efficiency are discovered in a timely manner, thereby improving the stability and reliability of the equipment.

[0028] (2) The present invention monitors the cold pressing state of the prepared powder to obtain the mass, temperature and moisture content of the powder prepared during the cold pressing process, thereby evaluating the cold pressing state of the prepared powder and adjusting the control conditions of the cold press in real time according to the cold pressing state of the prepared powder, thereby improving the cold pressing effect and product quality.

[0029] (3) The present invention monitors the sintering state of the blank to obtain the density and porosity of the blank during the sintering process, thereby quantitatively evaluating the sintering state of the blank and adjusting the sintering conditions in real time according to the sintering state of the blank to ensure that the sintering process is in the best state and improve the production quality of the hob.

[0030] (4) The present invention evaluates the cold pressing effect and sintering effect of the hob material respectively, thereby quantitatively evaluating the final processing quality of the hob material. By providing a hob quality evaluation method, risk points that may affect the processing quality and production efficiency can be discovered in a timely manner, so that preventive measures can be taken to reduce production risks and improve the stability and reliability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention is further described with reference to the accompanying drawings. However, the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative effort.

[0032] Figure 1 Schematic diagram of the control method of the present invention.

[0033] Figure 2 This is a flow chart for preparing the WC-Co-Ni-Re composite powder involved in an embodiment of the present invention.

[0034] Figure 3 This is a flow chart for preparing the new shield cutter teeth involved in an embodiment of the present invention.

[0035] Figure 4 Schematic diagram of the principle of the atmosphere-protected oscillating laser cladding process according to an embodiment of the present invention.

[0036] Figure 5 This is a schematic diagram of the structure of a new shield cutter disc with inserted teeth according to an embodiment of the present invention.

[0037] Figure 6 This is a finished product model diagram of the new shield insert cutter involved in an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0039] Reference Figure 1 As shown, the first aspect of the present invention provides a preparation control method for a shield insert hob, comprising: marking powder material for preparing hob teeth as preparation powder, and monitoring and controlling the pre-processing state of the preparation powder.

[0040] Specifically, the pre-processing status of the prepared powder is monitored, and the specific monitoring dimensions include: drying pretreatment of the prepared powder, uniformly mixing the prepared powder with 2.5wt% paraffin, placing it in a 60°C oven to dry for 1 hour and then sieving it, and cold pressing the dried prepared powder to obtain a blank, sintering the blank to obtain a cemented carbide block, using a pressure sintering furnace or a vacuum sintering furnace for sintering, and finally polishing the cemented carbide block according to the shape of the blade teeth.

[0041] It needs to be explained that the appearance of the new shield cutter is made according to the following design scheme: the lower end of the designed cutter tooth is a cylinder with a diameter of 20-25mm and a height of 20-25mm, and the bottom of the cylinder contains a ball pit (the center of the ball is about 1-2mm outward from the center of the bottom of the cylinder); the cylindrical connection is in the shape of a "mushroom head", and the side is the same width as the cylinder (that is, the width is the same as the radius); the two sides are "bowl-shaped", the bottom of the "bowl" is about 15-20mm long, and the mouth of the "bowl" is about 25-30mm long. The total height of the designed tooth is about 45-50mm.

[0042] Furthermore, powder drying pretreatment monitoring is carried out. The specific process is as follows: the moisture content and mass of the prepared powder are collected using radio frequency sensors and gravity sensors, and the material properties of the prepared powder, including melting point and thermal conductivity, are obtained from the hob manufacturing database. The characteristic values ​​of the prepared powder are comprehensively calculated to evaluate the heat resistance of the prepared powder and the required degree of drying, and serve as the basis for adjusting the operating temperature and working time of the oven.

[0043] What needs to be explained is that the working principle of the RF sensor in collecting the moisture content of the material is that the RF sensor will send an RF signal through the material. The propagation speed of the signal will be affected by the moisture content and material properties of the material. By measuring the propagation speed of the signal, the moisture content of the material can be calculated.

[0044] It needs to be explained that the material properties of the prepared powder include melting point and thermal conductivity. The melting point reflects the thermal stability of the prepared powder and is used to evaluate the heat resistance of the prepared powder. The higher the melting point of the prepared powder, the stronger the heat resistance and the higher the operating temperature of the oven. Thermal conductivity is an important physical quantity that describes the thermal conductivity of the material, which affects the temperature distribution and drying rate of the material during the drying process. The higher the thermal conductivity of the prepared powder, the faster the heat transfer and the shorter the drying time; the lower the thermal conductivity, the slower the heat transfer and the longer the drying time.

[0045] The characteristic values ​​of the powder prepared in this embodiment can be obtained not only by detection with dedicated equipment, but also by calculation using the following method.

[0046] In a specific embodiment, the characteristic value of the prepared powder is calculated using the following expression: Where α represents the characteristic value of the prepared powder, e represents the natural constant, Q1, R1 and G1 represent the melting point, moisture content and mass of the prepared powder, respectively, E represents the thermal conductivity of the prepared powder, ζ1, ζ2, ζ3 and ζ4 represent the material characteristic influencing factors corresponding to the unit values ​​of the melting point, moisture content, mass and thermal conductivity of the prepared powder, respectively.

[0047] The oven's operating temperature and operating time are combined to generate a label, which is marked as the oven working label. The prepared powder characteristic value is matched with the oven working label corresponding to each prepared powder characteristic value interval stored in the hob manufacturing database to obtain the oven working label corresponding to the prepared powder. This label is recorded as the designated label, and the oven is adjusted and controlled according to the oven's operating temperature and operating time in the designated label.

[0048] It needs to be explained that the characteristic values ​​of the prepared powder are determined by four parameters: the melting point, moisture content, mass and thermal conductivity of the prepared powder. The greater the melting point and thermal conductivity of the prepared powder, the smaller the moisture content and mass, the larger the corresponding characteristic values ​​of the prepared powder, the higher the working temperature of the oven, and the shorter the drying time. The material characteristic influencing factors corresponding to the unit values ​​of the melting point, moisture content, mass and thermal conductivity are introduced into the formula to improve the accuracy of the calculation results.

[0049] Specifically, the powder cold pressing treatment monitoring and control is prepared, and the specific process is: obtain the initial working parameters of the cold press, use a unidirectional pressure cold press at a pressing pressure of 6MPa, the pressed blank mass is 380-400g, and the pressing and cold pressing needs to be maintained for 10-15s.

[0050] Monitor the status of powder preparation during cold pressing, calculate the abnormal evaluation index of powder preparation during cold pressing, which is used to evaluate the cold pressing effect of powder preparation and serve as the basis for adjusting and controlling the working parameters of the cold press.

[0051] In a specific embodiment, the state of the prepared powder during cold pressing is monitored, and the mass, temperature, and moisture content of the prepared powder at a set time point are collected during the cold pressing process. The cold pressing interval duration corresponding to the set time point is counted, and the time point is marked as the target cold pressing time point. At the same time, a prepared powder reference data set of the prepared powder in each cold pressing interval duration range is obtained from the hob manufacturing database, and the prepared powder reference data set at the target cold pressing time point is extracted, including the reference material mass, reference material temperature, and reference material moisture content. The prepared powder cold pressing state abnormality evaluation index is comprehensively calculated. The prepared powder cold pressing state abnormality evaluation index can be obtained not only by detection with dedicated equipment, but also by the following calculation method. The specific calculation expression is: Wherein, β1 represents the abnormal evaluation index of the prepared powder cold pressing state, G2, Q2 and R2 represent the mass, temperature and moisture content of the prepared powder at the target cold pressing time point, respectively, G0, Q0 and R0 represent the mass, temperature and moisture content of the reference material at the target cold pressing time point, respectively, ΔG, ΔQ and ΔR represent the set defined mass deviation, defined temperature deviation and defined moisture content deviation, respectively, and ψ1, ψ2 and ψ3 represent the cold pressing state abnormality influencing factors corresponding to the set mass, temperature and moisture content, respectively.

[0052] It should be explained that in this embodiment, the mass, temperature and moisture content of the prepared powder are respectively collected by gravity sensors, temperature sensors and radio frequency sensors. During the cold pressing process, the temperature of the prepared powder needs to be controlled to be maintained within a certain range. At the same time, as the cold pressing process progresses, the mass and moisture content of the prepared powder will gradually decrease. By monitoring the mass, temperature and moisture content of the prepared powder, the cold pressing effect can be effectively evaluated and the processing quality can be controlled.

[0053] It should be explained that the abnormal cold pressing state evaluation index of the prepared powder is determined by the mass, temperature and moisture content of the prepared powder during the cold pressing process. The greater the deviation between the mass, temperature and moisture content of the prepared powder at a specific time point and the estimated mass, estimated temperature and estimated moisture content at that time point, the greater the corresponding abnormal cold pressing state evaluation index of the prepared powder. The cold pressing state abnormality influencing factors corresponding to the mass, temperature and moisture content are introduced into the formula to improve the accuracy of the calculation results.

[0054] In a specific embodiment, the cold pressing state of the prepared powder is monitored to obtain the mass, temperature and moisture content of the powder prepared during the cold pressing process, thereby evaluating the cold pressing state of the prepared powder, and adjusting the control conditions of the cold press in real time according to the cold pressing state of the prepared powder to improve the cold pressing effect and product quality.

[0055] The threshold value of the abnormal cold pressing state assessment index of the prepared powder is obtained from the hob manufacturing database, and the abnormal cold pressing state assessment index of the prepared powder is compared with the threshold value of the abnormal cold pressing state assessment index of the prepared powder. If the abnormal cold pressing state assessment index of the prepared powder is higher than the threshold value of the abnormal cold pressing state assessment index of the prepared powder, a feedback warning is issued, and the linear curve between the abnormal cold pressing state assessment index and the reference execution pressing speed, reference execution control temperature and reference execution control pressure of the cold press stored in the hob manufacturing database is extracted. The reference execution pressing speed, reference execution control temperature and reference execution control pressure of the cold press corresponding to the prepared powder are located and extracted in turn, and marked as the target execution pressing speed, target execution control temperature and target execution control pressure of the cold press for adjustment and control.

[0056] It should be explained that in this embodiment, the pressing speed, temperature and pressure of the cold press are adjusted. The pressing speed refers to the speed at which pressure is applied to the material during the cold pressing process. Different powder materials may require different cold pressing rates to achieve the best pressing effect. Therefore, the pressing speed can be adjusted to meet the needs of different materials. At the same time, when the temperature of the material changes abnormally, the temperature control parameters of the cold press need to be adjusted to ensure that the material is cold pressed within an appropriate temperature range. The pressure of the cold press is an important indicator to measure the ability of the cold press to apply pressure to the powder material. It is usually expressed in tons. The greater the pressure, the stronger the compaction force of the machine on the material, and it can handle powder materials of various hardness.

[0057] It needs to be explained that the linear curve between the cold press state abnormality assessment index and the cold press reference execution pressing speed, the cold press reference execution control temperature and the cold press reference execution control pressure, the curve uses the cold press state abnormality assessment index as the horizontal axis, the cold press reference execution pressing speed, the cold press reference execution control temperature and the cold press reference execution control pressure as the vertical axis, respectively, and is used to describe the linear relationship between the cold press state abnormality assessment index and the cold press reference execution pressing speed, the cold press reference execution control temperature and the cold press reference execution control pressure.

[0058] Specifically, the blank sintering process is monitored and controlled, and the specific process is: obtaining the initial working parameters of the sintering furnace, wherein the sintering temperature is controlled at about 1400°C, the sintering holding time is 1h, and the pressure in the pressure furnace is 2MPa.

[0059] The state of the blank during sintering is monitored, and the abnormal evaluation index of the blank sintering state is calculated to evaluate the sintering effect of the blank and serve as the basis for adjusting and controlling the working parameters of the sintering furnace.

[0060] In a specific embodiment, the state of the blank during sintering is monitored, and the density and porosity of the blank at a set sintering time point are collected during the sintering process. The sintering interval duration corresponding to the set sintering time point is counted, and the sintering time point is marked as the target sintering time point. At the same time, a blank reference data set of the blank in each sintering interval duration range is obtained from the hob manufacturing database, and the blank reference data set at the target sintering time point is extracted, including the reference blank density and the reference blank porosity. The blank sintering state abnormality evaluation index is comprehensively calculated. The blank sintering state abnormality evaluation index can be obtained not only by detection with dedicated equipment, but also by the following calculation method. The specific calculation expression is: Wherein, χ1 represents the evaluation index of the abnormal sintering state of the blank, P1 and D1 represent the blank density and blank porosity at the target sintering time point, respectively, ρ0 and D0 represent the reference blank density and reference blank porosity at the target sintering time point, respectively, Δρ and ΔD represent the set defined blank density deviation and defined blank porosity deviation, respectively, and ω1 and ω2 represent the sintering state abnormality influencing factors corresponding to the set density and porosity, respectively.

[0061] It should be explained that in this embodiment, the density and porosity of the blank are collected by X-ray diffraction method. As the sintering process progresses, the density of the blank gradually increases and the porosity of the blank gradually decreases. By monitoring the density and porosity of the blank, the sintering effect of the blank can be reflected and the sintering quality can be improved.

[0062] It should be explained that the blank sintering state abnormality assessment index is determined by the density and porosity of the blank during the sintering process. The greater the deviation between the density and porosity of the blank at a specific time point and the estimated density and estimated porosity at that time point, the greater the corresponding blank sintering state abnormality assessment index. The sintering state abnormality influencing factors corresponding to density and porosity are introduced into the formula to improve the accuracy of the calculation results.

[0063] In a specific embodiment, the sintering state of the blank is monitored to obtain the density and porosity of the blank during the sintering process, thereby quantitatively evaluating the sintering state of the blank, and adjusting the sintering conditions in real time according to the sintering state of the blank to ensure that the sintering process is in the best state and improve the quality of the product.

[0064] The blank sintering state abnormality assessment index threshold is obtained from the hob manufacturing database, and the blank sintering state abnormality assessment index is compared with the blank sintering state abnormality assessment index threshold. If the blank sintering state abnormality assessment index is higher than the blank sintering state abnormality assessment index threshold, a feedback warning is issued, and the linear curve between the sintering state abnormality assessment index stored in the hob manufacturing database and the sintering furnace reference execution sintering temperature and the sintering furnace reference execution furnace pressure is extracted. The sintering furnace reference execution sintering temperature and the sintering furnace reference execution furnace pressure corresponding to the blank are located and extracted in turn, and marked as the target execution sintering temperature and the target execution furnace pressure of the sintering furnace for adjustment and control.

[0065] It needs to be explained that the linear curve between the sintering state abnormality evaluation index and the sintering furnace reference execution sintering temperature and the sintering furnace reference execution furnace pressure, which takes the sintering state abnormality evaluation index as the horizontal axis, and the sintering furnace reference execution sintering temperature and the sintering furnace reference execution furnace pressure as the vertical axis, is used to describe the linear relationship between the sintering state abnormality evaluation index and the sintering furnace reference execution sintering temperature and the sintering furnace reference execution furnace pressure.

[0066] It should be explained that in this embodiment, the sintering temperature and pressure in the sintering furnace are adjusted. Temperature is one of the most important parameters in the sintering process. Different materials require different sintering temperatures. Too high or too low temperature will affect the performance of the material. At the same time, the pressure in the furnace is also an important parameter of the sintering furnace, which affects the sintering density and performance of the material.

[0067] During the powder preparation process, the machining quality of the hob cutter teeth is evaluated.

[0068] Specifically, the processing quality of the hob cutter teeth is evaluated, and the specific analysis process is: obtaining the blank quality evaluation index and the alloy block quality evaluation index, wherein the blank quality evaluation index represents the data obtained by quantitatively evaluating the quality of the blank after cold pressing, which is used to reflect the cold pressing effect during the tooth manufacturing process; the alloy block quality evaluation index represents the data obtained by quantitatively evaluating the quality of the alloy block after sintering, which is used to reflect the sintering effect during the tooth manufacturing process.

[0069] Calculate the tooth quality evaluation index, and its calculation expression is: Where φ represents the cutter tooth quality evaluation index, δ1 and δ2 represent the blank quality evaluation index and alloy block quality evaluation index, respectively, and υ1 and υ2 represent the cutter tooth quality influence weight factors corresponding to the set blank quality evaluation index and alloy block quality evaluation index, respectively.

[0070] It should be explained that, in this embodiment, the cutter tooth quality evaluation index is jointly determined by the blank quality evaluation index and the alloy block quality evaluation index. The hob cutter tooth processing technology needs to go through two processing processes of cold pressing and sintering. The cold pressing effect and the sintering effect will directly affect the final quality of the hob cutter teeth. By evaluating the quality of the blank obtained by cold pressing and the alloy block obtained by sintering, the final cutter tooth quality can be effectively reflected. At the same time, the cutter tooth quality influence weight factor corresponding to the blank quality evaluation index and the alloy block quality evaluation index is quoted in the formula to reflect the degree of influence of the cold pressing effect and the sintering effect on the cutter tooth quality, thereby improving the accuracy of the calculation results.

[0071] In a specific embodiment, the cold pressing effect and sintering effect of the hob material are evaluated respectively, thereby quantitatively evaluating the final processing quality of the hob material. By providing a hob quality evaluation method, risk points that may affect the processing quality and production efficiency can be discovered in a timely manner, so that preventive measures can be taken to reduce production risks and improve the stability and reliability of the equipment.

[0072] Specifically, the blank quality evaluation index has the following analysis and calculation process: extracting the critical moisture content of the cold-pressed blank and the estimated quality range of the cold-pressed blank from the hob manufacturing database, extracting the middle value of the estimated quality range of the cold-pressed blank as the reference cold-pressed quality standard value, and at the same time collecting the quality and moisture content of the blank after cold pressing, and comprehensively calculating the blank quality evaluation index for evaluating the quality of the blank after cold pressing.

[0073] In this embodiment, the rough blank quality evaluation index can be obtained not only by testing with dedicated equipment, but also by calculation using the following method. The specific calculation expression is: Where δ1 represents the blank quality assessment index, G3 and R3 represent the quality and moisture content of the blank after cold pressing, respectively, G′ represents the reference cold pressing quality standard value, ΔG′ represents the set allowable blank quality deviation, R′ represents the set critical moisture content of the material, ξ1 and ξ2 represent the quality assessment influencing factors corresponding to the set blank quality and blank moisture content, respectively.

[0074] It needs to be explained that in this embodiment, the cold press processes the powder to reduce the moisture content of the powder, and the quality of the powder will gradually decrease. By monitoring the moisture content of the blank and whether the final quality reaches the expected effect, the cold pressing effect can be evaluated. The lower the moisture content of the blank, the smaller the deviation between the quality and the expected effect, the larger the blank quality evaluation index, and the better the cold pressing effect. The quality evaluation influencing factors corresponding to the blank quality and the blank moisture content are introduced into the formula to improve the accuracy of the calculation results.

[0075] Furthermore, the alloy block quality evaluation index has a specific analysis process as follows: obtaining the reference standard mass and reference standard density of the alloy block from the hob manufacturing database, while collecting the mass and density of the alloy block after sintering, and comprehensively calculating the alloy block quality evaluation index for evaluating the quality of the alloy block after sintering.

[0076] In this embodiment, the quality evaluation index of the alloy block can be obtained not only by testing with dedicated equipment, but also by calculation using the following method. The specific calculation expression is: Wherein, δ2 represents the alloy block quality evaluation index, G4 and ρ2 represent the mass and density of the alloy block after sintering, respectively, G″ and ρ″ represent the reference standard mass and reference standard density of the alloy block, respectively, ΔG" and Δρ" represent the set deviation of the defined alloy block mass and the defined alloy block density, respectively, τ1 and τ2 represent the quality evaluation influencing factors corresponding to the set alloy block mass and alloy block density, respectively.

[0077] It should be explained that in this embodiment, special equipment is used to form a block or dense body by sintering a powdered material through high-temperature treatment to cause physical and chemical changes. The sintering effect can be evaluated by monitoring whether the quality and density of the alloy block meet the expected effect. The smaller the deviation between the quality and density of the alloy block and the expected effect, the greater the alloy block quality evaluation index and the better the sintering effect.

[0078] Reference Figure 2 、 Figure 3 As shown, the second aspect of the present invention provides a method for preparing a shield insert cutter, comprising: obtaining a WC-Co-Ni-Re composite powder, mixing the WC raw powder with a nickel oxalate monohydrate (NiC2O4·H2O) solution, and then co-precipitating with an ammonium oxalate monohydrate ((NH4)2C2O4·H2O) solution precipitant, while simultaneously introducing rare earth elements lanthanum (La) and yttrium (Y) during the co-precipitation stage to achieve synchronous encapsulation, and obtaining a precursor after filtration. After vacuum drying, high-temperature hydrogen reduction is performed to obtain WC@Ni-Re ultrafine powder. Finally, the WC@Ni-Re ultrafine powder, cobalt powder, ultra-coarse WC raw powder (WCUC), nickel powder, etc. are mixed in a certain proportion and placed in a ball mill for ball milling to obtain a WC-Co-Ni-Re composite powder with controllable strength and proportion.

[0079] The composite powder was evenly mixed with 2.5 wt.% paraffin wax. The paraffin wax was used as a lubricant or anti-sticking agent to reduce friction between materials during the pressing process, help demoulding, and make the pressing and molding smoother. The powder was placed in a 60° C. oven and dried for 1 hour before being sieved.

[0080] Using a unidirectional pressure cold press at a pressing pressure of 6MPa, the mass of the blank obtained is 380-400g, and the cold pressing needs to be maintained for 10-15s.

[0081] The alloy is formed in a pressure sintering furnace or a vacuum sintering furnace, wherein the sintering temperature is controlled at about 1400°C, the sintering holding time is 1 hour, the pressure in the pressure furnace is 2MPa, and after sintering, it is polished to the tooth shape described below.

[0082] The working temperature and working time of the oven, the pressing speed, temperature and pressing pressure of the cold press, and the sintering temperature and furnace pressure of the pressure sintering furnace or vacuum sintering furnace are all regulated by the preparation control method of the shield insert cutter.

[0083] Reference Figure 4 As shown, another embodiment of the present invention provides a wear-resistant layer cladding process. This process utilizes an atmosphere-protected oscillating laser cladding process. Combined with the addition of alloying elements such as Cr and Mo to the cutter ring material, Ni60A is selected and combined with an appropriate amount (20-30%) of spherical cast WC as the cutter ring wear-resistant coating component. Before cladding the hob cutter ring coating, the steel substrate on the cutter ring surface is pretreated with a laser cleaner to remove surface impurities. The Ni60A powder has a particle size of 53-150 μm, and the WC is spherical cast tungsten carbide with a particle size of 45 μm. The WC addition amount is 20-30%. A powder mixer is used for three-dimensional mechanical mixing. The resulting composite powder is then placed in a vacuum drying oven for drying to remove moisture. During cladding, a synchronous powder feeding method with a powder feeding rate of 7.28 g / min is used. A 3 mm diameter circular spot is used with a defocus of 13 mm. Nitrogen is selected as the shielding gas, the laser power is 1000 W, and the scanning speed is 4 mm / s.

[0084] Reference Figure 5 、 Figure 6As shown, another embodiment of the present invention provides an innovative method for hob assembly technology, which combines the internal stress simulation analysis of the hob cutter ring to optimize the assembly process. First, put the heating sleeve on the cutter body. When the heat is transferred to the inner hole of the cutter body, press the two tapered roller bearing outer sleeves into the inner holes on both sides of the cutter body, install the welded cutter ring retaining ring, cool to room temperature, put the sealing bracket rubber O-ring into the sealing groove of the sealing bracket, and then press the sealing bracket into the cutter body and close to the lower pressure cover, install the metal sealing ring and rubber energy ring, and finally form the cutter body assembly; install the rubber O-ring at the large end of the bearing into the sealing groove of the cutter shaft, and put the heated lower pressure cover sleeve on the installation position at the lower end of the cutter shaft, cool to room temperature, install the metal sealing ring and rubber energy ring; put the heated tapered roller bearing inner sleeve on the lower part of the cutter shaft, and cool to room temperature; The cutter body assembly is placed in the cutter shaft mounting position, the bearing spacer is positioned, the heated upper tapered roller bearing inner sleeve is inserted into the upper portion of the cutter shaft, and the cutter shaft is cooled to room temperature. The seal bracket rubber O-ring is placed into the seal bracket sealing groove, and the seal bracket is pressed into the cutter body against the upper gland. The metal sealing ring and rubber energy ring are installed in the upper gland sealing groove, the upper gland is installed, the lock nut is installed, and the starting torque of the hob is adjusted until it meets the design requirements. Air pressure is applied to the inner cavity of the cutter body to test the sealing performance of the inner cavity. If the design parameters are met, the assembly is qualified. Finally, the inner cavity of the hob seal is vacuumed and oiled, and the screw plug is installed, completing the assembly of the new shield hob. This achieves the optimized design and preparation of a new shield insert hob based on new carbide teeth.

[0085] In a specific embodiment, a preparation method and control method of a shield cutter hob are provided, the cold pressing state and sintering state of the hob material are monitored, the density and porosity of the blank during the sintering process are obtained, and the processing state of the hob material is evaluated, thereby adjusting the processing control parameters in real time to improve the processing effect. At the same time, by quantitatively evaluating the final processing quality of the hob material, risk points that may affect the processing quality and production efficiency are discovered in a timely manner, thereby improving the stability and reliability of the equipment.

[0086] The above content is merely an example and explanation of the structure of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A method for preparing and controlling a shield insert cutter, characterized in that: include: Mark the powder material for preparing the hob teeth as prepared powder, and monitor and control the pre-processing status of the prepared powder; During the powder preparation process, the machining quality of the hob cutter teeth is evaluated.

2. The method for preparing and controlling a shield insert cutter according to claim 1, characterized in that: The monitoring of the pre-processing status of the powder preparation includes the following specific monitoring dimensions: monitoring and control of the powder preparation drying pre-treatment, monitoring and control of the powder preparation and pressing treatment, and monitoring and control of the blank sintering treatment.

3. The method for preparing and controlling a shield insert cutter according to claim 2, characterized in that: The preparation of powder drying pretreatment monitoring, the specific process is: The moisture content and mass of the prepared powder are collected, and the material properties of the prepared powder, including melting point and thermal conductivity, are obtained from the hob manufacturing database. The characteristic values ​​of the prepared powder are comprehensively calculated to evaluate the heat resistance and required degree of drying of the prepared powder, and serve as the basis for adjusting the working temperature and working time of the oven. The working temperature and working time of the oven are combined to generate a label, which is marked as the oven working label. The characteristic values ​​of the prepared powder are matched with the oven working labels corresponding to each preparation powder characteristic value interval stored in the hob manufacturing database to obtain the oven working label corresponding to the prepared powder, which is recorded as the designated label. The oven is then adjusted and controlled according to the working temperature and working time of the oven in the designated label.

4. The method for preparing and controlling a shield insert cutter according to claim 2, wherein: The specific process of monitoring and controlling the cold pressing treatment of the prepared powder is as follows: Obtain the initial working parameters of the cold press; Monitor the status of powder preparation during cold pressing and calculate the abnormal evaluation index of powder preparation during cold pressing. This is used to evaluate the cold pressing effect of powder preparation and serve as the basis for adjusting and controlling the working parameters of the cold press. The threshold value of the abnormal cold pressing state evaluation index of the prepared powder is obtained from the hob manufacturing database, and the abnormal cold pressing state evaluation index of the prepared powder is compared with the threshold value of the abnormal cold pressing state evaluation index of the prepared powder. If the abnormal cold pressing state evaluation index of the prepared powder is higher than the threshold value of the abnormal cold pressing state evaluation index of the prepared powder, a feedback warning is issued, and the linear curve between the abnormal cold pressing state evaluation index and the reference execution pressing speed, reference execution control temperature and reference execution control pressure of the cold press stored in the hob manufacturing database is extracted. The reference execution pressing speed, reference execution control temperature and reference execution control pressure of the cold press corresponding to the prepared powder are located and extracted in turn, and marked as the target execution pressing speed, target execution control temperature and target execution control pressure of the cold press for adjustment and control.

5. The method for preparing and controlling a shield insert cutter according to claim 2, wherein: The monitoring and control of the blank sintering process is as follows: Obtain the initial operating parameters of the sintering furnace; Monitor the status of the blank during sintering and calculate the abnormal evaluation index of the blank sintering status to evaluate the sintering effect of the blank and serve as the basis for adjusting and controlling the working parameters of the sintering furnace; The blank sintering state abnormality assessment index threshold is obtained from the hob manufacturing database, and the blank sintering state abnormality assessment index is compared with the blank sintering state abnormality assessment index threshold. If the blank sintering state abnormality assessment index is higher than the blank sintering state abnormality assessment index threshold, a feedback warning is issued, and the linear curve between the sintering state abnormality assessment index stored in the hob manufacturing database and the sintering furnace reference execution sintering temperature and the sintering furnace reference execution furnace pressure is extracted. The sintering furnace reference execution sintering temperature and the sintering furnace reference execution furnace pressure corresponding to the blank are located and extracted in turn, and marked as the target execution sintering temperature and the target execution furnace pressure of the sintering furnace for adjustment and control.

6. The method for preparing and controlling a shield insert cutter according to claim 1, characterized in that: The specific analysis process for evaluating the machining quality of hob teeth is as follows: Obtaining a blank quality evaluation index and an alloy block quality evaluation index, wherein the blank quality evaluation index represents data obtained by quantitatively evaluating the quality of the blank after cold pressing, and is used to reflect the pressing effect during the tooth manufacturing process; the alloy block quality evaluation index represents data obtained by quantitatively evaluating the quality of the alloy block after sintering, and is used to reflect the sintering effect during the tooth manufacturing process; Calculate the tooth quality evaluation index, and its calculation expression is: Where φ represents the cutter tooth quality evaluation index, δ1 and δ2 represent the blank quality evaluation index and alloy block quality evaluation index, respectively, and υ1 and υ2 represent the cutter tooth quality influence weight factors corresponding to the set blank quality evaluation index and alloy block quality evaluation index, respectively.

7. The method for preparing and controlling a shield insert cutter according to claim 6, characterized in that: The specific analysis process of the rough blank quality evaluation index is as follows: The critical moisture content of the cold-pressed blank and the estimated quality range of the cold-pressed blank are extracted from the hob manufacturing database. The middle value of the estimated quality range of the cold-pressed blank is extracted as the reference cold-pressed quality standard value. At the same time, the quality and moisture content of the blank after pressing are collected, and the blank quality evaluation index is comprehensively calculated to evaluate the quality of the blank after pressing.

8. The method for preparing and controlling a shield insert cutter according to claim 6, characterized in that: The specific analysis process of the alloy block quality evaluation index is as follows: The reference standard mass and reference standard density of the alloy block are obtained from the hob manufacturing database. The mass and density of the alloy block after sintering are also collected. The alloy block quality evaluation index is comprehensively calculated to evaluate the quality of the alloy block after sintering.

9. A method for preparing a shield insert hob, characterized in that: include: A WC-Co-Ni-Re composite powder was obtained, and the composite powder was uniformly mixed with 2.5 wt.% paraffin wax, placed in a 60°C oven to dry for 1 hour, and then sieved; Using a unidirectional cold press at a pressing pressure of 6MPa, the blank mass obtained is 380-400g, and the pressing and cold pressing needs to be maintained for 10-15s; The alloy is formed in a pressure sintering furnace or a vacuum sintering furnace, wherein the sintering temperature is controlled at about 1400°C, the sintering holding time is 1 hour, the pressure in the pressure furnace is 2MPa, and after sintering, it is polished to the tooth shape described below; The working temperature and working time of the oven, the pressing speed, temperature and pressing pressure of the cold press, and the sintering temperature and furnace pressure of the pressure sintering furnace or vacuum sintering furnace are all regulated by the preparation control method of the shield insert cutter as described in any one of claims 1 to 8.

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