[go: up one dir, main page]

WO2021026750A1 - Porous valve guide and processing process thereof - Google Patents

Porous valve guide and processing process thereof Download PDF

Info

Publication number
WO2021026750A1
WO2021026750A1 PCT/CN2019/100327 CN2019100327W WO2021026750A1 WO 2021026750 A1 WO2021026750 A1 WO 2021026750A1 CN 2019100327 W CN2019100327 W CN 2019100327W WO 2021026750 A1 WO2021026750 A1 WO 2021026750A1
Authority
WO
WIPO (PCT)
Prior art keywords
green body
porous
valve guide
porous valve
mixed powder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2019/100327
Other languages
French (fr)
Chinese (zh)
Inventor
周龙
白玲
张天亮
孙善良
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Weichai Power Co Ltd
Original Assignee
Weichai Power Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Weichai Power Co Ltd filed Critical Weichai Power Co Ltd
Priority to PCT/CN2019/100327 priority Critical patent/WO2021026750A1/en
Publication of WO2021026750A1 publication Critical patent/WO2021026750A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/16—Both compacting and sintering in successive or repeated steps
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B22F5/12—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product of wires
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L3/00—Lift-valve, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces; Parts or accessories thereof
    • F01L3/08—Valves guides; Sealing of valve stem, e.g. sealing by lubricant

Definitions

  • the invention relates to the technical field of valve guides, in particular to a porous valve guide and its processing technology.
  • the valve guide is a guide device for the engine valve, which guides the valve and transfers the heat on the valve stem to the cylinder head through the valve guide.
  • the valve guide has poor dirt holding capacity, poor corrosion resistance, poor heat dissipation performance, and relatively high cost.
  • the purpose of the present invention is to provide a porous valve guide and its processing technology.
  • the porous valve guide prepared by the processing technology has high oil storage capacity, dirt holding capacity and corrosion resistance.
  • the present invention provides the following technical solutions:
  • a processing technology of a porous valve guide including the steps:
  • the mixed powder A and the mixed powder B are respectively pressed and molded by the compression molding method to obtain a tubular green body A and a tubular green body B; the green body B can be clearance fit with the inner hole of the green body A;
  • Sintered product the green body B and the green body A are correspondingly inserted and matched to obtain a green tube, which is sintered in a protective gas atmosphere to obtain a porous valve tube with a porous inner wall layer and a dense outer wall layer.
  • the mass percentage of ammonium bicarbonate in the mixed powder B is 0.1%-50%.
  • the mixed powder A and the mixed powder B are mixed by a ball milling method.
  • the pressing pressure is 50-500 MPa
  • the pressing temperature is 10°C to 250°C
  • the pressing time is 1 minute to 2 hours.
  • a low pressure sintering method or a hot isostatic pressing technique is used for sintering, the sintering temperature is 850° C. to 1300° C., and the sintering time is 0.5 hour to 50 hours.
  • the protective gas used is argon or nitrogen.
  • the principle of the processing technology provided by this scheme is: the green body B mixed with ammonium bicarbonate and the green body A without ammonium bicarbonate are sintered together.
  • the ammonium bicarbonate in the green body B decomposes into Carbon dioxide, water and ammonia gas form pores.
  • the ammonia gas decomposes active N under the catalysis of nickel.
  • N has a strong affinity with Fe, and therefore reacts with Fe to form ⁇ phase (Fe2-3N), due to the ammonium bicarbonate content in the green body B
  • the ⁇ phase (Fe2-3N) also blocks the diffusion of active N into the interior.
  • the green body B forms the pearlite + ⁇ phase (Fe2-3N).
  • the green body A forms ferrite + pearlite during the sintering process. Because the chemical composition and structure of the surface of the green body B on the inner ring have been changed, the surface modification treatment of the inner wall of the catheter is completed while the finished product is sintered. This processing method can improve the material performance of the catheter. In this way, a surface-modified porous inner wall layer and an outer dense and dense outer wall layer are formed.
  • the porous valve guide prepared by this process has good lubrication effect, cooling effect, dirt holding capacity and corrosion resistance.
  • the present invention also provides a porous valve guide, the porous valve guide is made by the processing technology as described in any one of the above, the main body of the porous valve guide is a cylindrical structure, including a porous inner wall layer located in the inner ring And the dense outer wall layer located in the outer ring.
  • the porous valve guide has good oil storage capacity, dirt holding capacity and corrosion resistance, can reduce the friction work loss between the guide tube and the valve stem, and prevent the guide tube and the valve stem from sticking.
  • the porous material of the porous inner wall layer includes ⁇ -phase tissue and pearlite tissue
  • the dense outer wall layer includes pearlite tissue and ferrite tissue.
  • Figure 1 is a front view of a porous valve guide in a specific embodiment of the present invention.
  • Figure 2 is a side view of a porous valve guide in a specific embodiment of the present invention.
  • Figure 3 is a schematic cross-sectional view of a porous valve guide in a specific embodiment of the present invention.
  • Fig. 4 is a partial enlarged schematic diagram of part A in Fig. 3.
  • Catheter body-1 porous inner wall layer-11, dense outer wall layer-12, chamfer-13.
  • Figure 1 is a front view of a porous valve guide in a specific embodiment of the present invention
  • Figure 2 is a side view of a porous valve guide in a specific embodiment of the present invention
  • Figure 3 is a specific embodiment of the present invention
  • Fig. 4 is a partial enlarged schematic view of part A in Fig. 3.
  • the present invention provides a processing technology of a porous valve guide, which belongs to a powder metallurgy processing technology and mainly includes the following steps:
  • the above-mentioned mixed powder A and mixed powder B can be mixed by a ball milling method or a conventional powder mixing method. In this solution, the ball milling method is preferably used for mixing;
  • the mixed powder A and the mixed powder B are respectively pressed and formed by the compression molding method to obtain the green body A and the green body B.
  • Both the green body A and the green body B are tubular structures, and the green body B can be combined with the green body
  • the inner hole of A has a clearance fit, so that the green body B can be inserted and fitted into the tube hole of the green body A to form a duct green body; preferably, the pressure of the compression molding is 50-500MPa, and the temperature of the compression molding is 10°C ⁇ 250°C, the time for compression molding is 1 minute to 2 hours;
  • Sintered product The green body B and the green body A are correspondingly inserted and matched to obtain a ducted green body, which is sintered in a protective gas atmosphere by low-pressure sintering method or hot isostatic pressing technology to obtain a surface-modified porous inner wall layer 11 and dense
  • the porous valve guide of the outer wall layer 12 wherein the sintering temperature is preferably 850°C to 1300°C, the sintering time is 0.5 hours to 50 hours, and the protective gas used is argon or nitrogen.
  • the principle of the processing technology provided by this scheme is: the green body B mixed with ammonium bicarbonate and the green body A without ammonium bicarbonate are sintered together.
  • the ammonium bicarbonate in the green body B decomposes into Carbon dioxide (CO2), water (H2O) and ammonia (NH3) form pores.
  • CO2 Carbon dioxide
  • H2O water
  • NH3 ammonia
  • ammonia gas decomposes active nitrogen (N) under the catalysis of nickel.
  • N has a strong affinity with Fe, so it reacts with Fe to form ⁇ phase (Fe2-3N).
  • the content of ammonium bicarbonate in the green body B is limited.
  • the ⁇ phase (Fe2-3N) also prevents the active N from diffusing into the interior.
  • These ⁇ phases (Fe2-3N) are mostly distributed on the surface of the pores, so that the green body B becomes pearlescent Body + ⁇ phase (Fe2-3N).
  • the green body A forms ferrite + pearlite during the sintering process. In this way, the surface-modified porous inner wall layer 11 and the outer dense and dense outer wall layer 12 are formed.
  • the porous valve guide prepared by this process has good lubrication effect, cooling effect, dirt holding capacity and corrosion resistance.
  • the processing technology provided by the invention has high efficiency, and the surface modification and sintering preparation are completed in the same process, so that the inner wall of the catheter has a porous structure, and the oil storage capacity, dirt holding capacity and corrosion resistance of the catheter are enhanced.
  • the present invention also provides a porous valve guide.
  • the porous valve guide is made by the processing technique described in any one of the above.
  • the guide body 1 of the porous valve guide is a cylindrical structure and includes a porous inner wall layer 11 located on the inner ring. And the dense outer wall layer 12 located in the outer ring.
  • the porous valve guide has good lubricity, cooling properties, oil storage capacity, dirt holding capacity and corrosion resistance, can reduce the frictional work loss between the guide tube and the valve stem, and prevent the guide tube and the valve stem from sticking.
  • the porous structure material can hold more lubricating oil, and can correspondingly improve the dirt holding capacity of the conduit, and prevent impurities from causing damage to the friction pair.
  • the porous material after surface modification can improve its strength and corrosion resistance, and greatly increase its service life and reliability.
  • the two ends of the catheter body 1 are also provided with chamfers 13 as shown in FIG. 1.
  • the porous material of the porous inner wall layer 11 includes epsilon phase structure (Fe2-3N) and pearlite structure, and the dense outer wall layer 12 includes pearlite structure and ferrite structure.
  • the porous inner wall layer 11 also has a small amount of ferrite.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • General Engineering & Computer Science (AREA)
  • Powder Metallurgy (AREA)

Abstract

Disclosed are a porous valve guide and a processing process thereof. The processing process comprises the following steps: mixing an iron powder and a carbon powder according to a set iron-carbon mass ratio to obtain a mixed powder A, and taking part of the mixed powder A and mixing with ammonium bicarbonate to obtain a mixed powder B; press molding the mixed powder A and the mixed powder B, respectively by using a press molding method to obtain a tubular green body A and a tubular green body B, wherein the green body B can be in clearance fit with an inner hole of the green body A; and fitting the green body B and the green body A correspondingly in an insertion manner to obtain a guide green body, and sintering the guide green body under the atmosphere of a protective gas to obtain a porous valve guide, with a porous inner wall layer (11) and a compact outer wall layer (12), that has a modified surface.

Description

一种多孔气门导管及其加工工艺Porous valve guide and its processing technology 技术领域Technical field

本发明涉及气门导管技术领域，尤其涉及一种多孔气门导管及其加工工艺。The invention relates to the technical field of valve guides, in particular to a porous valve guide and its processing technology.

背景技术Background technique

气门导管是发动机气门的导向装置，对气门起导向作用，并使气门杆上的热量经气门导管传递给气缸盖。随着高速内燃机的升功率越来越高，对于气门与气门导管的配合要求也越来越高。在市场上多次出现柴油机上的气门导管与气门杆粘结故障，轻则造成气门断裂、推杆弯曲，重则造成活塞拉缸、连杆断裂，甚至捣缸，给发动机带来极大的危害。造成气门导管与气门杆粘结的原因主要为润滑不良、导管锈蚀等，这就需要对于气门导管与气门杆的摩擦副提供较多的润滑油和较好的容污能力，以降低磨损的可能性。现有的气门导管容污能力较差、耐蚀性较差、散热性能差且成本相对较高。The valve guide is a guide device for the engine valve, which guides the valve and transfers the heat on the valve stem to the cylinder head through the valve guide. With the increasing power of high-speed internal combustion engines, the requirements for the cooperation of valves and valve guides are also increasing. In the market, there have been many failures in the adhesion of valve guides and valve stems on diesel engines, which may cause valve breakage and push rod bending, and at worst, cause piston pulling, connecting rod breakage, and even ramming of the cylinder, which brings great damage to the engine. harm. The main reasons for the adhesion of valve guide and valve stem are poor lubrication and tube corrosion. This requires more lubricating oil and better dirt holding capacity for the friction pair of valve guide and valve stem to reduce the possibility of wear Sex. The existing valve guide has poor dirt holding capacity, poor corrosion resistance, poor heat dissipation performance, and relatively high cost.

因此，如何提高气门导管的润滑性和容污性，是本领域技术人员目前需要解决的技术问题。Therefore, how to improve the lubricity and dirt holding capacity of the valve guide is a technical problem that needs to be solved by those skilled in the art.

发明内容Summary of the invention

有鉴于此，本发明的目的在于提供一种多孔气门导管及其加工工艺，通过该加工工艺制得的多孔气门导管具有很高的储油能力、容污能力和耐蚀性。In view of this, the purpose of the present invention is to provide a porous valve guide and its processing technology. The porous valve guide prepared by the processing technology has high oil storage capacity, dirt holding capacity and corrosion resistance.

为了实现上述目的，本发明提供了如下技术方案：In order to achieve the above objective, the present invention provides the following technical solutions:

一种多孔气门导管的加工工艺，包括步骤：A processing technology of a porous valve guide, including the steps:

制备粉末：将铁粉和碳粉按照设定铁碳质量比进行混合，得到混合粉末A；取部分混合粉末A并加入碳酸氢铵进行混合，得到混合粉末B；Prepare powder: mix iron powder and carbon powder according to the set iron-carbon mass ratio to obtain mixed powder A; take a part of mixed powder A and add ammonium bicarbonate to mix to obtain mixed powder B;

压制生坯：将混合粉末A和混合粉末B分别采用压模法压制成型，得到管状的生坯A和管状的生坯B；生坯B能够与生坯A的内孔间隙配合；Pressing the green body: the mixed powder A and the mixed powder B are respectively pressed and molded by the compression molding method to obtain a tubular green body A and a tubular green body B; the green body B can be clearance fit with the inner hole of the green body A;

烧结成品：将生坯B与生坯A对应插入配合，得到导管生坯，在保护气体氛围下进行烧结，得到具有多孔内壁层和致密外壁层的多孔气门导管。Sintered product: the green body B and the green body A are correspondingly inserted and matched to obtain a green tube, which is sintered in a protective gas atmosphere to obtain a porous valve tube with a porous inner wall layer and a dense outer wall layer.

优选地，在上述多孔气门导管的加工工艺中，在制备粉末步骤中，设定铁 碳质量比为Fe：C＝(97％～99％)：(1％～3％)。Preferably, in the above-mentioned processing technology of the porous valve guide, in the powder preparation step, the mass ratio of iron to carbon is set as Fe:C=(97%-99%):(1%-3%).

优选地，在上述多孔气门导管的加工工艺中，在制备粉末步骤中，碳酸氢铵在混合粉末B中的质量百分比为0.1％～50％。Preferably, in the above-mentioned processing technology of the porous valve guide, in the powder preparation step, the mass percentage of ammonium bicarbonate in the mixed powder B is 0.1%-50%.

优选地，在上述多孔气门导管的加工工艺中，在制备粉末步骤中，混合粉末A和混合粉末B均采用球磨法进行混合。Preferably, in the above-mentioned processing technology of the porous valve guide, in the powder preparation step, the mixed powder A and the mixed powder B are mixed by a ball milling method.

优选地，在上述多孔气门导管的加工工艺中，在压制生坯步骤中，压制成型的压力为50～500MPa，压制成型的温度为10℃～250℃，压制成型的时间为1分钟～2小时。Preferably, in the above-mentioned processing technology of the porous valve guide, in the step of pressing the green body, the pressing pressure is 50-500 MPa, the pressing temperature is 10°C to 250°C, and the pressing time is 1 minute to 2 hours. .

优选地，在上述多孔气门导管的加工工艺中，在烧结成品步骤中，采用低压烧结法或热等静压技术进行烧结，烧结温度为850℃～1300℃，烧结时间为0.5小时～50小时。Preferably, in the process of processing the porous valve guide, in the step of sintering the finished product, a low pressure sintering method or a hot isostatic pressing technique is used for sintering, the sintering temperature is 850° C. to 1300° C., and the sintering time is 0.5 hour to 50 hours.

优选地，在上述多孔气门导管的加工工艺中，在烧结成品步骤中，采用的保护气体为氩气或氮气。Preferably, in the above-mentioned processing technique of the porous valve guide, in the step of sintering the finished product, the protective gas used is argon or nitrogen.

本方案提供的加工工艺的原理为：混合有碳酸氢铵的生坯B和未混合碳酸氢铵的生坯A一同烧结，当温度升至180℃时，生坯B中的碳酸氢铵分解为二氧化碳、水和氨气，形成孔洞。当温度继续升高，氨气在镍的催化下分解出活性N，N与Fe具有极强的亲和力，因而和Fe反应生成ε相(Fe2-3N)，由于生坯B中的碳酸氢铵含量是有限的，同时，ε相(Fe2-3N)也阻挡活性N向内部扩散，这些ε相(Fe2-3N)大多分布于气孔表面，从而使生坯B形成珠光体+ε相(Fe2-3N)。而生坯A在烧结过程中形成铁素体+珠光体。由于位于内圈的生坯B表面的化学成分和组织结构发生了改变，因此，在烧结成品的同时也完成了导管内壁的表面改性处理，该处理方法可以提高导管的材料性能。这样就形成了经表面改性的多孔内壁层和外侧致密的致密外壁层。该工艺制得的多孔气门导管具有良好的润滑效果、冷却效果、容污性和耐蚀性。The principle of the processing technology provided by this scheme is: the green body B mixed with ammonium bicarbonate and the green body A without ammonium bicarbonate are sintered together. When the temperature rises to 180°C, the ammonium bicarbonate in the green body B decomposes into Carbon dioxide, water and ammonia gas form pores. When the temperature continues to rise, the ammonia gas decomposes active N under the catalysis of nickel. N has a strong affinity with Fe, and therefore reacts with Fe to form ε phase (Fe2-3N), due to the ammonium bicarbonate content in the green body B At the same time, the ε phase (Fe2-3N) also blocks the diffusion of active N into the interior. Most of these ε phases (Fe2-3N) are distributed on the surface of the pores, so that the green body B forms the pearlite + ε phase (Fe2-3N). ). The green body A forms ferrite + pearlite during the sintering process. Because the chemical composition and structure of the surface of the green body B on the inner ring have been changed, the surface modification treatment of the inner wall of the catheter is completed while the finished product is sintered. This processing method can improve the material performance of the catheter. In this way, a surface-modified porous inner wall layer and an outer dense and dense outer wall layer are formed. The porous valve guide prepared by this process has good lubrication effect, cooling effect, dirt holding capacity and corrosion resistance.

本发明还提供了一种多孔气门导管，该多孔气门导管采用如上任一项所述的加工工艺制得，所述多孔气门导管的导管主体为圆筒状结构，包括位于内圈的多孔内壁层和位于外圈的致密外壁层。该多孔气门导管具有良好的储油能力、容污能力和耐蚀性，能够降低导管与气门杆的摩擦功损失，同时防止导管与气门杆粘结。The present invention also provides a porous valve guide, the porous valve guide is made by the processing technology as described in any one of the above, the main body of the porous valve guide is a cylindrical structure, including a porous inner wall layer located in the inner ring And the dense outer wall layer located in the outer ring. The porous valve guide has good oil storage capacity, dirt holding capacity and corrosion resistance, can reduce the friction work loss between the guide tube and the valve stem, and prevent the guide tube and the valve stem from sticking.

优选地，在上述多孔气门导管中，所述多孔内壁层的多孔材料包含ε相组织和珠光体组织，所述致密外壁层包含珠光体组织和铁素体组织。Preferably, in the above-mentioned porous valve catheter, the porous material of the porous inner wall layer includes ε-phase tissue and pearlite tissue, and the dense outer wall layer includes pearlite tissue and ferrite tissue.

附图说明Description of the drawings

为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

图1为本发明具体实施例中的多孔气门导管的主视图；Figure 1 is a front view of a porous valve guide in a specific embodiment of the present invention;

图2为本发明具体实施例中的多孔气门导管的侧视图；Figure 2 is a side view of a porous valve guide in a specific embodiment of the present invention;

图3为本发明具体实施例中的多孔气门导管的横截面示意图；Figure 3 is a schematic cross-sectional view of a porous valve guide in a specific embodiment of the present invention;

图4为图3中A部分的局部放大示意图。Fig. 4 is a partial enlarged schematic diagram of part A in Fig. 3.

图1至图4中：In Figure 1 to Figure 4:

导管主体-1、多孔内壁层-11、致密外壁层-12、倒角-13。Catheter body-1, porous inner wall layer-11, dense outer wall layer-12, chamfer-13.

具体实施方式detailed description

下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a 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 those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

请参照图1至图4，图1为本发明具体实施例中的多孔气门导管的主视图；图2为本发明具体实施例中的多孔气门导管的侧视图；图3为本发明具体实施例中的多孔气门导管的横截面示意图；图4为图3中A部分的局部放大示意图。Please refer to Figures 1 to 4. Figure 1 is a front view of a porous valve guide in a specific embodiment of the present invention; Figure 2 is a side view of a porous valve guide in a specific embodiment of the present invention; Figure 3 is a specific embodiment of the present invention A schematic cross-sectional view of the porous valve guide in Fig. 4; Fig. 4 is a partial enlarged schematic view of part A in Fig. 3.

在一种具体实施例方案中，本发明提供了一种多孔气门导管的加工工艺，该加工工艺属于一种粉末冶金加工工艺，主要包括以下步骤：In a specific embodiment, the present invention provides a processing technology of a porous valve guide, which belongs to a powder metallurgy processing technology and mainly includes the following steps:

制备粉末：将铁粉(Fe粉)和碳粉(C粉)按照设定铁碳质量比进行混合，得到混合粉末A，优选地，设定铁碳质量比为Fe：C＝(97％～99％)：(1％～3％)；再取部分混合粉末A并加入碳酸氢铵进行混合，得到混合粉末B，碳酸氢铵在混合粉末B中的质量百分比优选为0.1％～50％；其中，上述混合粉末A和混合粉末B均可以采用球磨法或者常规混粉法进行混合，本方案中优选采用球磨法进行混合；Prepare powder: mix iron powder (Fe powder) and carbon powder (C powder) according to the set iron-carbon mass ratio to obtain mixed powder A. Preferably, set the iron-carbon mass ratio as Fe:C=(97%～ 99%): (1% to 3%); then take a part of the mixed powder A and add ammonium bicarbonate to mix to obtain mixed powder B. The mass percentage of ammonium bicarbonate in the mixed powder B is preferably 0.1%-50%; Among them, the above-mentioned mixed powder A and mixed powder B can be mixed by a ball milling method or a conventional powder mixing method. In this solution, the ball milling method is preferably used for mixing;

压制生坯：将混合粉末A和混合粉末B分别采用压模法压制成型，得到生 坯A和生坯B，生坯A和生坯B均为管状结构，并且，生坯B能够与生坯A的内孔间隙配合，这样就可以使得生坯B插入配合到生坯A的管孔中以形成导管生坯；优选地，压制成型的压力为50～500MPa，压制成型的温度为10℃～250℃，压制成型的时间为1分钟～2小时；Pressing the green body: the mixed powder A and the mixed powder B are respectively pressed and formed by the compression molding method to obtain the green body A and the green body B. Both the green body A and the green body B are tubular structures, and the green body B can be combined with the green body The inner hole of A has a clearance fit, so that the green body B can be inserted and fitted into the tube hole of the green body A to form a duct green body; preferably, the pressure of the compression molding is 50-500MPa, and the temperature of the compression molding is 10°C~ 250°C, the time for compression molding is 1 minute to 2 hours;

烧结成品：将生坯B与生坯A对应插入配合，得到导管生坯，在保护气体氛围下采用低压烧结法或热等静压技术进行烧结，得到表面改性的具有多孔内壁层11和致密外壁层12的多孔气门导管；其中，烧结温度优选为850℃～1300℃，烧结时间为0.5小时～50小时，采用的保护气体为氩气或氮气。Sintered product: The green body B and the green body A are correspondingly inserted and matched to obtain a ducted green body, which is sintered in a protective gas atmosphere by low-pressure sintering method or hot isostatic pressing technology to obtain a surface-modified porous inner wall layer 11 and dense The porous valve guide of the outer wall layer 12; wherein the sintering temperature is preferably 850°C to 1300°C, the sintering time is 0.5 hours to 50 hours, and the protective gas used is argon or nitrogen.

本方案提供的加工工艺的原理为：混合有碳酸氢铵的生坯B和未混合碳酸氢铵的生坯A一同烧结，当温度升至180℃时，生坯B中的碳酸氢铵分解为二氧化碳(CO2)、水(H2O)和氨气(NH3)，形成孔洞。当温度继续升高，在高温环境下，氨气在镍的催化下分解出活性氮(N)，N与Fe具有极强的亲和力，因而和Fe反应生成ε相(Fe2-3N)，由于生坯B中的碳酸氢铵含量是有限的，同时，ε相(Fe2-3N)也阻挡活性N向内部扩散，这些ε相(Fe2-3N)大多分布于气孔表面，从而使生坯B形成珠光体+ε相(Fe2-3N)。而生坯A在烧结过程中形成铁素体+珠光体。这样就形成了经表面改性的多孔内壁层11和外侧致密的致密外壁层12。该工艺制得的多孔气门导管具有良好的润滑效果、冷却效果、容污性和耐蚀性。The principle of the processing technology provided by this scheme is: the green body B mixed with ammonium bicarbonate and the green body A without ammonium bicarbonate are sintered together. When the temperature rises to 180°C, the ammonium bicarbonate in the green body B decomposes into Carbon dioxide (CO2), water (H2O) and ammonia (NH3) form pores. When the temperature continues to rise, in a high-temperature environment, ammonia gas decomposes active nitrogen (N) under the catalysis of nickel. N has a strong affinity with Fe, so it reacts with Fe to form ε phase (Fe2-3N). The content of ammonium bicarbonate in the green body B is limited. At the same time, the ε phase (Fe2-3N) also prevents the active N from diffusing into the interior. These ε phases (Fe2-3N) are mostly distributed on the surface of the pores, so that the green body B becomes pearlescent Body + ε phase (Fe2-3N). The green body A forms ferrite + pearlite during the sintering process. In this way, the surface-modified porous inner wall layer 11 and the outer dense and dense outer wall layer 12 are formed. The porous valve guide prepared by this process has good lubrication effect, cooling effect, dirt holding capacity and corrosion resistance.

本发明提供的加工工艺效率高，表面改性和烧结制备在同一过程完成，这样使得导管内壁为多孔结构，增强了导管的储油能力、容污能力和耐蚀性。The processing technology provided by the invention has high efficiency, and the surface modification and sintering preparation are completed in the same process, so that the inner wall of the catheter has a porous structure, and the oil storage capacity, dirt holding capacity and corrosion resistance of the catheter are enhanced.

本发明还提供了一种多孔气门导管，该多孔气门导管采用如上任一项所述的加工工艺制得，多孔气门导管的导管主体1为圆筒状结构，包括位于内圈的多孔内壁层11和位于外圈的致密外壁层12。该多孔气门导管具有良好的润滑性、冷却性、储油能力、容污能力和耐蚀性，能够降低导管与气门杆的摩擦功损失，同时防止导管与气门杆粘结。多孔结构的材料能够容纳较多的润滑油，并且能够相应提高导管的容污能力，防止杂质对摩擦副造成伤害。经表面改性后的多孔材料能够提高其强度和耐蚀性，大大提高其使用寿命和可靠性。另外，导管主体1的两端还设有倒角13，如图1所示。The present invention also provides a porous valve guide. The porous valve guide is made by the processing technique described in any one of the above. The guide body 1 of the porous valve guide is a cylindrical structure and includes a porous inner wall layer 11 located on the inner ring. And the dense outer wall layer 12 located in the outer ring. The porous valve guide has good lubricity, cooling properties, oil storage capacity, dirt holding capacity and corrosion resistance, can reduce the frictional work loss between the guide tube and the valve stem, and prevent the guide tube and the valve stem from sticking. The porous structure material can hold more lubricating oil, and can correspondingly improve the dirt holding capacity of the conduit, and prevent impurities from causing damage to the friction pair. The porous material after surface modification can improve its strength and corrosion resistance, and greatly increase its service life and reliability. In addition, the two ends of the catheter body 1 are also provided with chamfers 13 as shown in FIG. 1.

优选地，在上述多孔气门导管中，多孔内壁层11的多孔材料包含ε相组织(Fe2-3N)和珠光体组织，致密外壁层12包含珠光体组织和铁素体组织。其中，多孔内壁层11也有少量的铁素体。Preferably, in the above-mentioned porous valve catheter, the porous material of the porous inner wall layer 11 includes epsilon phase structure (Fe2-3N) and pearlite structure, and the dense outer wall layer 12 includes pearlite structure and ferrite structure. Among them, the porous inner wall layer 11 also has a small amount of ferrite.

对所公开的实施例的上述说明，使本领域专业技术人员能够实现或使用本发明。对这些实施例的多种修改对本领域的专业技术人员来说将是显而易见的，本文中所定义的一般原理可以在不脱离本发明的精神或范围的情况下，在其它实施例中实现。因此，本发明将不会被限制于本文所示的这些实施例，而是要符合与本文所公开的原理和新颖特点相一致的最宽的范围。The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown in this document, but should conform to the widest scope consistent with the principles and novel features disclosed in this document.

Claims (9)

一种多孔气门导管的加工工艺，其特征在于，包括步骤：A processing technology of a porous valve guide, which is characterized in that it comprises the following steps: 制备粉末：将铁粉和碳粉按照设定铁碳质量比进行混合，得到混合粉末A；取部分混合粉末A并加入碳酸氢铵进行混合，得到混合粉末B；Prepare powder: mix iron powder and carbon powder according to the set iron-carbon mass ratio to obtain mixed powder A; take a part of mixed powder A and add ammonium bicarbonate to mix to obtain mixed powder B; 压制生坯：将混合粉末A和混合粉末B分别采用压模法压制成型，得到管状的生坯A和管状的生坯B；生坯B能够与生坯A的内孔间隙配合；Pressing the green body: the mixed powder A and the mixed powder B are respectively pressed and molded by the compression molding method to obtain a tubular green body A and a tubular green body B; the green body B can be clearance fit with the inner hole of the green body A; 烧结成品：将生坯B与生坯A对应插入配合，得到导管生坯，在保护气体氛围下进行烧结，得到具有多孔内壁层和致密外壁层的多孔气门导管。Sintered product: the green body B and the green body A are correspondingly inserted and matched to obtain a green tube, which is sintered in a protective gas atmosphere to obtain a porous valve tube with a porous inner wall layer and a dense outer wall layer. 根据权利要求1所述的多孔气门导管的加工工艺，其特征在于，在制备粉末步骤中，设定铁碳质量比为Fe：C＝(97％～99％)：(1％～3％)。The processing technology of the porous valve guide according to claim 1, wherein in the powder preparation step, the mass ratio of iron to carbon is set as Fe:C=(97%～99%):(1%～3%) . 根据权利要求1所述的多孔气门导管的加工工艺，其特征在于，在制备粉末步骤中，碳酸氢铵在混合粉末B中的质量百分比为0.1％～50％。The processing technology of the porous valve guide according to claim 1, wherein in the powder preparation step, the mass percentage of ammonium bicarbonate in the mixed powder B is 0.1%-50%. 根据权利要求1所述的多孔气门导管的加工工艺，其特征在于，在制备粉末步骤中，混合粉末A和混合粉末B均采用球磨法进行混合。The processing technology of the porous valve guide according to claim 1, wherein in the powder preparation step, the mixed powder A and the mixed powder B are mixed by a ball milling method. 根据权利要求1所述的多孔气门导管的加工工艺，其特征在于，在压制生坯步骤中，压制成型的压力为50～500MPa，压制成型的温度为10℃～250℃，压制成型的时间为1分钟～2小时。The processing technology of the porous valve guide according to claim 1, wherein in the step of pressing the green body, the pressure of the pressing is 50-500MPa, the temperature of the pressing is 10℃-250℃, and the time of the pressing is 1 minute to 2 hours. 根据权利要求1所述的多孔气门导管的加工工艺，其特征在于，在烧结成品步骤中，采用低压烧结法或热等静压技术进行烧结，烧结温度为850℃～1300℃，烧结时间为0.5小时～50小时。The process for processing porous valve guides according to claim 1, wherein in the step of sintering the finished product, low pressure sintering or hot isostatic pressing is used for sintering, the sintering temperature is 850°C to 1300°C, and the sintering time is 0.5 Hours to 50 hours. 根据权利要求6所述的多孔气门导管的加工工艺，其特征在于，在烧结成品步骤中，采用的保护气体为氩气或氮气。The processing process of the porous valve guide according to claim 6, wherein the protective gas used in the step of sintering the finished product is argon or nitrogen. 一种多孔气门导管，其特征在于，所述多孔气门导管采用如权利要求1至7中任一项所述的加工工艺制得，所述多孔气门导管的导管主体(1)为圆筒状结构，包括位于内圈的多孔内壁层(11)和位于外圈的致密外壁层(12)。A porous valve guide, characterized in that, the porous valve guide is made by the processing technology according to any one of claims 1 to 7, and the guide body (1) of the porous valve guide has a cylindrical structure , Including a porous inner wall layer (11) located in the inner ring and a dense outer wall layer (12) located in the outer ring. 根据权利要求8所述的多孔气门导管，其特征在于，所述多孔内壁层(11)的多孔材料包含ε相组织和珠光体组织，所述致密外壁层(12)包含珠光体组织和铁素体组织。The porous valve catheter according to claim 8, wherein the porous material of the porous inner wall layer (11) comprises ε-phase structure and pearlite tissue, and the dense outer wall layer (12) comprises pearlite tissue and ferrite. Body tissue.
PCT/CN2019/100327 2019-08-13 2019-08-13 Porous valve guide and processing process thereof Ceased WO2021026750A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2019/100327 WO2021026750A1 (en) 2019-08-13 2019-08-13 Porous valve guide and processing process thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2019/100327 WO2021026750A1 (en) 2019-08-13 2019-08-13 Porous valve guide and processing process thereof

Publications (1)

Publication Number Publication Date
WO2021026750A1 true WO2021026750A1 (en) 2021-02-18

Family

ID=74569735

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2019/100327 Ceased WO2021026750A1 (en) 2019-08-13 2019-08-13 Porous valve guide and processing process thereof

Country Status (1)

Country Link
WO (1) WO2021026750A1 (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1766865A (en) * 1923-04-06 1930-06-24 Gen Motors Res Corp Alloy structure
CN2625586Y (en) * 2003-04-28 2004-07-14 重庆智博粉末冶金有限公司 Motorcycle valve guide conduit roughcast
JP2007002808A (en) * 2005-06-27 2007-01-11 Komatsu Ltd Valve guide
CN101507352A (en) * 2006-07-28 2009-08-12 加州大学评议会 Joined concentric tubes
CN108825324A (en) * 2018-05-19 2018-11-16 滁州普立惠技术服务有限公司 A kind of porous type valve guide bushing

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1766865A (en) * 1923-04-06 1930-06-24 Gen Motors Res Corp Alloy structure
CN2625586Y (en) * 2003-04-28 2004-07-14 重庆智博粉末冶金有限公司 Motorcycle valve guide conduit roughcast
JP2007002808A (en) * 2005-06-27 2007-01-11 Komatsu Ltd Valve guide
CN101507352A (en) * 2006-07-28 2009-08-12 加州大学评议会 Joined concentric tubes
CN108825324A (en) * 2018-05-19 2018-11-16 滁州普立惠技术服务有限公司 A kind of porous type valve guide bushing

Similar Documents

Publication Publication Date Title
JP6386676B2 (en) Sintered valve seat
WO2021026750A1 (en) Porous valve guide and processing process thereof
CN101092969A (en) Turbocharger sealing structure and method thereof
CN108672696B (en) Sintered bearing for EGR valve and method for manufacturing same
WO2014041976A1 (en) Machine component made of ferrous sintered metal
CN201651037U (en) Double-inner ring angular contact ball bearing without lock amount in inner rings
CN105777170B (en) A kind of self-lubricating ceramic bearing and preparation method thereof
CN220523851U (en) Sintered alloy valve guide
JP2004340128A (en) Valve train for internal combustion engine
CN216811815U (en) Rocker arm bushing and cylinder cover
CN110860692B (en) High-airtightness powder metallurgy valve guide pipe and processing method and application thereof
JPH0953422A (en) Copper infiltrated Fe-based sintered alloy valve guide member with excellent wear resistance and low opponent attack
CN208433842U (en) A kind of air-resistance type hydrogen cooled generator inner grease retainer
JPH0953421A (en) Fe-based sintered alloy valve guide member with excellent wear resistance and low opponent attack
CN221742824U (en) A pneumatic diaphragm pump structure
CN204402606U (en) A kind of load-carrying natural gas used for automobile valve oil seal
CN205089512U (en) Needle valve and needle valve idol piece of diesel engine fuel sprayer
CN208719334U (en) A kind of piston rod
CN221664784U (en) An oil filter with magnetic adsorption function
CN202431360U (en) Improved turbine shaft of supercharger
CN211500745U (en) Combination structure of valve and valve seat
KR102554929B1 (en) Engine piston and manufacturing method thereof
CN110145417B (en) Pressurizing device for improving EGR rate
CN208380700U (en) Carbocyclic ring is scraped in a kind of platform reticulate pattern nitriding reinforcing
JP6720362B2 (en) Sintered bearing for EGR valve

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19941519

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19941519

Country of ref document: EP

Kind code of ref document: A1