A new method for preparing a press wheel for large-scale automated woodworking machines

Abstract

The present application relates to the technical field of woodworking machinery equipment manufacturing, and discloses a novel preparation method of a pressing wheel for large automatic woodworking machinery, which adopts 45 steel round bar material, and after blanking, the material is subjected to preliminary mechanical processing to obtain a primary workpiece, the obtained primary workpiece is placed into an atmosphere protection heat treatment furnace for preliminary heat treatment, the primary workpiece after the preliminary heat treatment is processed by using a high-precision machine tool, the inner hole is preliminarily enlarged for finish machining, a margin is reserved for the inner hole of the primary workpiece, a secondary workpiece is obtained after processing, then the secondary workpiece is directly placed into a gas carburizing furnace, and the pressing wheel is obtained after processing, the pressing wheel is cooled in air after being discharged from the furnace, the pressing wheel is placed into a sealed furnace, nitrogen, ammonia and a beautifying agent are introduced, and heating is performed, and the pressing wheel is cooled in air after processing. The present application has no three waste emissions, is green and environmentally friendly, easy to operate, low in cost, and far higher in surface hardness, wear resistance and corrosion resistance than the technical index requirements.

Description

Technical Field

[0001] This invention relates to the field of woodworking machinery manufacturing technology, and more specifically to a novel method for preparing a pressing wheel for large-scale automated woodworking machinery. Background Technology

[0002] Pressing rollers in large woodworking machinery require not only high surface hardness but also corrosion resistance, necessitating surface treatment technology. Currently, all domestic manufacturers use electroplating chromium to meet these technical requirements. It is well known that acid pickling is required before chromium plating, but trivalent chromium in the plating solution is carcinogenic. Indiscriminate discharge of this wastewater would severely pollute the environment. Due to stringent national environmental regulations, some small electroplating companies have closed, while large companies must rigorously treat their wastewater before discharge, significantly increasing production costs. Furthermore, the corrosion resistance of electroplated chromium depends on the thickness of the plating layer. To reduce costs, many companies control the plating layer thickness to a minimum, resulting in corrosion resistance that often fails to meet salt spray test standards.

[0003] Therefore, how to provide a novel method for preparing pressing wheels for large-scale automated woodworking machinery is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides a novel preparation method for pressing wheels for large-scale automated woodworking machinery. The production process is free of waste, environmentally friendly, easy to operate, and low in cost. Moreover, the surface hardness, wear resistance, and corrosion resistance of the prepared pressing wheels far exceed the technical requirements.

[0005] To achieve the above objectives, the present invention provides a novel method for preparing a pressing wheel for large-scale automated woodworking machinery, comprising the following steps:

[0006] Step (1), rough machining of materials: 45 steel round bar material is used. After blanking, the material is subjected to preliminary machining to obtain the primary workpiece;

[0007] Step (2), preheat treatment: The primary workpiece obtained in step (1) is placed in an atmosphere-protected heat treatment furnace for preheat treatment. The primary workpiece is placed on a tooling rack and pushed into the heat treatment furnace for the first heating. After being taken out of the furnace, it is cooled in 20°C water. Then the primary workpiece is put back into the heat treatment furnace for a second heating. After being taken out of the furnace, it is cooled in the air.

[0008] Step (3), finishing process: The primary workpiece, after pre-heat treatment, is finished using a high-precision machine tool. The finishing process increases the inner hole to allow for a certain amount of allowance in the inner hole of the primary workpiece wheel. After finishing, the secondary workpiece is obtained. The formula for the relationship between the thickness and the increase in diameter is:

[0009] ΔΦ=0.0912×H

[0010] Where: ΔΦ - the increment of the inner diameter Φ of the pressing wheel, in micrometers; H - the thickness of the compound layer after multi-element co-percolation, in micrometers;

[0011] Step (4), gas co-infiltration treatment: The secondary workpiece after the finishing in step (3) is directly put into the gas co-infiltration furnace. The pressure inside the co-infiltration furnace is always maintained at a positive pressure of 200~1200Pa. After the treatment, the pressing wheel is obtained, and then the pressing wheel is directly taken out of the furnace and cooled in the air.

[0012] Step (5), beautification treatment: Place the pressing wheel after step (4) into a sealed furnace, introduce nitrogen, ammonia and beautifying agent, and heat it. After the treatment, place the pressing wheel in the air to cool.

[0013] Preferably, the temperature of the first heating in step (2) is 840-860°C and the time is 1 hour.

[0014] Preferably, the heating temperature for the secondary heating in step (2) is 580-620°C and the time is 1.5 hours.

[0015] Preferably, the temperature of the gas co-infiltration furnace in step (4) is 580-680°C and the co-infiltration time is 1.0-2.5 hours.

[0016] Preferably, the atmosphere in the co-infiltration furnace in step (4) is a mixture of ammonia, natural gas, carbon dioxide, nitrogen and additives, wherein the additives are a mixture of methanol, acetone, formamide and alcohol.

[0017] Preferably, the beautifying agent used in step (5) is a mixture of alcohol and acetone.

[0018] Preferably, the heating temperature in step (5) is 400-600°C and the heating time is 1.5 hours.

[0019] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. This invention eliminates the polluting electroplating technology. It can directly carry out multi-element co-diffusion without any acid washing, alkali washing or other treatments in the early stage. The entire production process has no emissions of waste, achieving green production.

[0021] 2. This invention can be applied to specific production furnaces that have already been developed (such as...). Figure 4 Production can be carried out in a way that is easy to operate and has low cost;

[0022] 3. The finished pressing wheel prepared by this invention has a protection level of 8 or above after passing a 120-hour neutral salt spray corrosion test, which is far higher than the technical specification of a 48-hour neutral salt spray test and a protection level of 8 required for the pressing wheel.

[0023] 4. The finished pressing wheel prepared by this invention has a surface hardness similar to that of chrome plating, and a thickness greater than that of chrome plating. Most importantly, its surface friction coefficient is only 0.2-0.3 (0.6-0.7 for steel and about 0.5 for chrome plating), thus greatly improving its wear resistance. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 This is a flowchart illustrating the novel preparation method of the pressing wheel for large-scale automated woodworking machinery according to the present invention.

[0026] Figure 2 A schematic diagram of the metallographic structure of a pressing wheel manufactured using the novel preparation method of the pressing wheel for large-scale automated woodworking machinery according to the present invention.

[0027] Figure 3 This is a schematic diagram of a pressing wheel manufactured according to the novel preparation method of the pressing wheel for large-scale automated woodworking machinery of the present invention.

[0028] Figure 4 This is a schematic diagram of the structure of a specific production furnace of the present invention.

[0029] Figure 5 This is a schematic diagram of the specially designed tooling frame of the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please see the appendix Figure 1-5This invention discloses a novel preparation method for pressing wheels used in large-scale automated woodworking machinery.

[0032] The present invention provides a novel method for preparing a pressing wheel for large-scale automated woodworking machinery, comprising the following steps:

[0033] Step (1), rough machining of materials: 45 steel round bar material is used. After blanking, the material is subjected to preliminary machining to obtain a primary workpiece that initially meets the dimensional requirements;

[0034] Step (2), preheat treatment: The primary workpiece obtained in step (1) is placed in an atmosphere-protected heat treatment furnace for preheat treatment. The primary workpiece is placed on a tooling rack and pushed into the heat treatment furnace for the first heating. After being taken out of the furnace, it is cooled in 20°C water. Then the primary workpiece is put back into the heat treatment furnace for a second heating. After being taken out of the furnace, it is cooled in the air.

[0035] Step (3), finishing process: The primary workpiece, after pre-heat treatment, is finished using a high-precision machine tool. The finishing process increases the inner hole to allow for a certain amount of allowance in the inner hole of the primary workpiece. After finishing, the secondary workpiece is obtained. The formula for the relationship between the thickness and the increase in diameter is:

[0036] ΔΦ=0.0912×H

[0037] Where: ΔΦ - the increment of the inner diameter Φ of the pressing wheel, in micrometers; H - the thickness of the compound layer after multi-element co-percolation, in micrometers;

[0038] It should be noted that, in order to meet the requirements for surface hardness and corrosion resistance of the pressing wheel, a multi-element co-diffusion treatment is required in the later stage. The inner hole of the pressing wheel will deform. Since the tolerance of the inner hole of the finished product is relatively strict, a margin must be reserved. Through a large number of experiments, this invention found that the inner hole will shrink after the multi-element co-diffusion treatment. Therefore, the inner hole must be enlarged in advance during the finishing process. The above-mentioned formula for the relationship between thickness and diameter increase is also obtained through a combination of a large number of experiments and theory.

[0039] Step (4), gas co-infiltration treatment: The secondary workpiece after the finishing in step (3) is directly put into the gas co-infiltration furnace. The pressure inside the co-infiltration furnace is always maintained at a positive pressure of 200~1200Pa. After the treatment, the pressing wheel is obtained. Then the pressing wheel is directly taken out of the furnace and cooled in the air. Although the surface hardness, wear resistance and corrosion resistance of the pressing wheel obtained in this step can meet the requirements, the surface color is not neat and beautiful.

[0040] Step (5), beautification treatment: Place the pressing wheel after step (4) into a sealed furnace, introduce nitrogen, ammonia and beautifying agent, and heat it. After the treatment, place the pressing wheel in the air to cool.

[0041] To further optimize the above technical solution, the temperature of the first heating in step (2) is 840-860℃ and the time is 1 hour.

[0042] To further optimize the above technical solution, the heating temperature of the secondary heating in step (2) is 580-620℃ and the time is 1.5 hours.

[0043] In order to further optimize the above technical solution, the temperature of the gas co-infiltration furnace in step (4) is 580-680℃ and the co-infiltration time is 1.0-2.5 hours.

[0044] In order to further optimize the above technical solution, the atmosphere in the co-infiltration furnace in step (4) is a mixture of ammonia, natural gas, carbon dioxide, nitrogen and additives, wherein the additives are a mixture of methanol, acetone, formamide and alcohol.

[0045] To further optimize the above technical solution, the beautifying agent used in step (5) is a mixture of alcohol and acetone.

[0046] To further optimize the above technical solution, the heating temperature in step (5) is 400-600℃ and the time is 1.5 hours.

[0047] The pressing wheel produced by the above method has a 30-50 micrometer compound layer containing multiple elements on its surface, followed by a transition layer with a thickness of 0.2-0.4 mm. The compound layer has a hardness of HV500-650, and the transition layer has a hardness of HV450-350, which is much higher than that of the base material. At the same time, the compound layer is an intermetallic compound with good corrosion resistance, thus ensuring wear resistance and corrosion resistance. The outermost layer is an aesthetic layer with a thickness of 3-5 micrometers, which ensures the cleanliness and aesthetics of the pressing wheel's surface.

[0048] Example 1:

[0049] The novel method for preparing the pressing roller in this embodiment includes the following processing steps:

[0050] (1) Materials and rough machining process: 45 steel round bar material is used. After cutting, the material is subjected to preliminary machining to obtain rough pressing wheel. The dimensions of each part are reserved by 0.5-1.0mm compared with the drawing requirements. The processing quantity is 50 pieces.

[0051] (2) Preheat treatment: The 50 pressing wheels obtained in step (1) are placed in an atmosphere-protected heat treatment furnace for preheat treatment. The pressing wheels are placed on a specially made tooling rack (such as... Figure 5The workpiece is placed in a heat treatment furnace for heating at 840℃ for 1 hour. After being taken out of the furnace, it is cooled in 20℃ water. Then, the workpiece is put back into the heat treatment furnace for a second heating at 580℃ for 1.5 hours. After being taken out of the furnace, it is cooled in the air.

[0052] (3) Finishing process: The pressing wheel, which has been preheated in step (2), is processed using a high-precision machine tool. The inner diameter is processed to Φ17+0.029-Φ17+0.008, and the remaining parts are processed to the dimensions required by the drawing.

[0053] (4) Gas co-infiltration treatment: The pressing roller after the finishing process in step (3) is directly put into a gas co-infiltration furnace at 580℃, and various gases are introduced as shown in Table 1:

[0054] Table 1. Gas flow rate in Example 1 (multi-element co-osmosis)

[0055]

[0056] Co-infiltration lasts for 2.5 hours, with the pressure inside the co-infiltration furnace maintained at a positive pressure of 500-600 Pa. After processing, the pressing roller is removed directly from the furnace and cooled in the air.

[0057] (5) Aesthetic treatment: Place the pressing roller processed in step (4) into a specific production oven that has been developed (such as...). Figure 4 In a process involving nitrogen, ammonia, and a beautifying agent, nitrogen gas, ammonia gas, and a heating agent are introduced. The heating temperature is 450℃ and the time is 1.5 hours. The types of gases introduced are shown in Table 2.

[0058] Table 2. Gas flow rate for beautification treatment in Example 1.

[0059]

[0060] In this embodiment, the compound layer thickness in the surface impregnation layer of the pressure roller is 40 micrometers, the total impregnation layer thickness is 0.15 millimeters, and the beautification layer is 2-3 micrometers; after 96 hours of salt spray test, the protection level is level 8.

[0061] Cost calculation for Example 1: 2.5 yuan / piece, cost of traditional technology: 4.0 yuan / piece.

[0062] Example 2:

[0063] The difference between Example 2 and Example 1 is that the number of pressing rollers used in the multi-element co-permeation process is greatly increased in Example 2, which requires changes to the multi-element co-permeation and beautification process, as follows.

[0064] The novel method for preparing the pressing roller in this embodiment includes the following processing steps:

[0065] (1) Materials and rough machining process: 45 steel round bars are used. After cutting, the materials are subjected to preliminary machining to obtain rough pressing wheels. The dimensions of each part are 0.5-1.0mm reserved compared with the drawing requirements. The processing quantity is 200 pieces; a special tooling frame is used.

[0066] (2) Preheat treatment: The 200 pressing wheels obtained in step (1) are placed in an atmosphere-protected heat treatment furnace for preheat treatment. The pressing wheels are placed on a specially made tooling rack (such as... Figure 5 The workpiece is placed in a heat treatment furnace for heating at 850℃ for 2.0 hours. After being taken out of the furnace, it is cooled in 20℃ water. Then, the workpiece is put back into the heat treatment furnace for a second heating at 600℃ for 2.5 hours. After being taken out of the furnace, it is cooled in the air.

[0067] (3) Finishing process: The pressing wheel, which has been preheated in step (2), is processed using a high-precision machine tool. The inner diameter is processed to Φ17+0.028-Φ17+0.07. The remaining parts are processed to the dimensions required by the drawing.

[0068] (4) Gas co-infiltration treatment: The pressing roller after the finishing process in step (3) is directly put into a gas co-infiltration furnace at 600℃, and various gases are introduced as shown in Table 3:

[0069] Table 3. Gas flow rate during multi-element co-osmosis in Example 2

[0070]

[0071] The co-infiltration process lasts for 2.5 hours, with the pressure inside the co-infiltration furnace maintained at a positive pressure of 800-600 Pa. After processing, the pressing roller is removed directly from the furnace and cooled in the air.

[0072] (5) Aesthetic treatment: Place the pressing roller processed in step (4) into a specific production oven that has been developed (such as...). Figure 4 Nitrogen, ammonia, and a beautifying agent are introduced into the chamber, and the heating temperature is 500℃ for 2.0 hours. The types of gases introduced are shown in Table 4.

[0073] Table 4. Gas flow rate for beautification treatment in Example 2

[0074]

[0075] In this embodiment, the compound layer thickness in the surface impregnation layer of the pressure roller is 35 micrometers, the total impregnation layer thickness is 0.12 millimeters, and the beautification layer is 2-3 micrometers; after 96 hours of salt spray test, the protection level is level 8.

[0076] The method for preparing the pressing roller of the present invention has the following advantages compared with the traditional method:

[0077] 1) It adopts multi-element co-diffusion technology and waste electroplating chromium technology. No acid washing or alkali washing is required in the early stage, and the whole production process is green and environmentally friendly.

[0078] 2) The relationship between the deformation of the pressing wheel and the allowance for finishing during the multi-element co-infiltration process was explored, which can be expressed by the following formula.

[0079] ΔΦ=0.0912×H

[0080] In the formula, ΔΦ is the increment of the inner diameter Φ of the pressing wheel, in micrometers; H is the thickness of the compound layer after multi-element co-percolation, in micrometers.

[0081] 3) Research and develop beautification processes to ensure the neat and beautiful appearance of products and improve the pass rate.

[0082] 4) The cost is reduced by about 35% compared to traditional processes, and the performance is far superior to traditional technologies.

[0083] Therefore, compared with traditional methods, the processing of this invention is simplified. Electroplating chromium cannot precisely control the dimensions, so grinding is necessary after plating to ensure the dimensions. This invention explores the relationship between deformation and compound layer, and eliminates the need for subsequent grinding by pre-reserving a certain amount.

[0084] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A novel method for preparing a pressing wheel for large-scale automated woodworking machinery, characterized in that, Includes the following steps: Step (1), rough machining of materials: 45 steel round bar material is used. After blanking, the material is subjected to preliminary machining to obtain the primary workpiece; Step (2), preheat treatment: The primary workpiece obtained in step (1) is placed in an atmosphere-protected heat treatment furnace for preheat treatment. The primary workpiece is placed on a tooling rack and pushed into the heat treatment furnace for the first heating. After being taken out of the furnace, it is cooled in 20°C water. Then the primary workpiece is put back into the heat treatment furnace for a second heating. After being taken out of the furnace, it is cooled in the air. Step (3), finishing process: The primary workpiece, after pre-heat treatment, is finished using a high-precision machine tool. The finishing process increases the inner hole to allow for a certain amount of allowance in the inner hole of the primary workpiece wheel. After finishing, the secondary workpiece is obtained. The formula for the relationship between the thickness and the increase in diameter is: ΔΦ=0.0912×H Where: ΔΦ - the increment of the inner diameter Φ of the pressing wheel, in micrometers; H - the thickness of the compound layer after multi-element co-percolation, in micrometers; Step (4), gas co-infiltration treatment: The secondary workpiece after the finishing in step (3) is directly put into the gas co-infiltration furnace. The gas co-infiltration furnace is always kept under a positive pressure of 200~1200Pa. After the treatment, a pressing wheel is obtained. Then the pressing wheel is directly taken out of the furnace and cooled in the air. Step (5), beautification treatment: Place the pressing wheel after step (4) into a sealed furnace, introduce nitrogen, ammonia and beautifying agent, and heat it. After the beautification treatment is completed, place the pressing wheel in the air to cool. In step (4), the atmosphere in the gas co-infiltration furnace is a mixture of ammonia, natural gas, carbon dioxide, nitrogen and additives, wherein the additives are a mixture of methanol, acetone, formamide and alcohol. In step (4), the temperature of the gas co-infiltration furnace is 580-680℃, and the co-infiltration time is 1.0-2.5 hours; The beautifying agent used in step (5) is a mixture of alcohol and acetone; The temperature of the first heating in step (2) is 840-860℃, and the time is 1 hour; The heating temperature for the secondary heating in step (2) is 580-620℃, and the time is 1.5 hours; In step (5), the heating temperature is 400-600℃ and the time is 1.5 hours.

Images