CN112065862A - Double-overhead cam bearing seat, manufacturing process, testing machine and testing method - Google Patents

Double-overhead cam bearing seat, manufacturing process, testing machine and testing method Download PDF

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Publication number
CN112065862A
CN112065862A CN202010768648.9A CN202010768648A CN112065862A CN 112065862 A CN112065862 A CN 112065862A CN 202010768648 A CN202010768648 A CN 202010768648A CN 112065862 A CN112065862 A CN 112065862A
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China
Prior art keywords
base
overhead cam
upper cover
test block
cam bearing
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Pending
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CN202010768648.9A
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Chinese (zh)
Inventor
李楠
高磊
雷健
李智
袁海波
苏振兴
田朕
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Dongfeng Trucks Co ltd
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Dongfeng Trucks Co ltd
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Priority to CN202010768648.9A priority Critical patent/CN112065862A/en
Publication of CN112065862A publication Critical patent/CN112065862A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C35/00—Rigid support of bearing units; Housings, e.g. caps, covers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
    • B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
    • B23P15/003—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass bearings
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/40—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rings; for bearing races
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C21/00—Alloys based on aluminium
    • C22C21/02—Alloys based on aluminium with silicon as the next major constituent
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
    • C22F1/043—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with silicon as the next major constituent
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2202/00—Solid materials defined by their properties
    • F16C2202/02—Mechanical properties
    • F16C2202/06—Strength or rigidity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2204/00—Metallic materials; Alloys
    • F16C2204/20—Alloys based on aluminium
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2220/00—Shaping
    • F16C2220/02—Shaping by casting
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2220/00—Shaping
    • F16C2220/40—Shaping by deformation without removing material
    • F16C2220/46—Shaping by deformation without removing material by forging
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2220/00—Shaping
    • F16C2220/60—Shaping by removing material, e.g. machining
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2223/00—Surface treatments; Hardening; Coating
    • F16C2223/10—Hardening, e.g. carburizing, carbo-nitriding
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2360/00—Engines or pumps
    • F16C2360/18—Camshafts

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)

Abstract

The invention relates to a double overhead cam bearing seat, a manufacturing process, a testing machine and a testing method, wherein the manufacturing process comprises the following steps: the base is made of aluminum-silicon cast aluminum alloy, and the weight percentage of silicon is 6.5% -11.0%; and the upper cover is arranged on the base. According to the double overhead cam bearing block, the manufacturing process, the testing machine and the testing method, the base has enough wear resistance, meanwhile, the manufacturing of an aluminum-based bushing is reduced, and materials are saved; the hardness of the base is lower than that of steel, so that the slender oil hole is easy to machine on the base, and the machining cost is reduced; and because the weight of aluminium silicon series casting aluminum alloy is lighter than steel material, the base chooses aluminium silicon series casting aluminum alloy material for use can reduce the total weight of double overhead cam bearing frame.

Description

Double-overhead cam bearing seat, manufacturing process, testing machine and testing method
Technical Field
The invention relates to the technical field of automobile engine valve actuating mechanisms, in particular to a double overhead cam bearing seat, a manufacturing process of the double overhead cam bearing seat, a sapphire fatigue strength testing machine and a testing method of the sapphire fatigue strength testing machine.
Background
In order to meet increasingly stringent emission regulations and simultaneously improve the power per liter and reduce the oil consumption of the engine, the heavy-duty diesel engine gradually adopts a double overhead camshaft design. The double overhead cam bearing block comprises a base and an upper cover, wherein the base is fixed at the top of the cylinder cover, and the upper cover is arranged on the base through a bolt; when the double overhead cam bearing seat works, the cam shaft penetrates through the cam bearing holes on the two sides and applies downward pressure, the maximum force range is 6000N-6500N, and a friction pair is generated between the base and the cam shaft, so that the base can resist wear and reduce abrasion during manufacturing; the rocker shaft mounting hole needs to bear 16000N-18000N force when the engine is in an exhaust braking working condition, and therefore the upper cover of the cam bearing seat needs to have enough strength.
In the related art, the base of the conventional cam bearing seat is made of gray iron, the upper cover is made of ductile iron or forged steel to ensure the structural strength, and at the same time, a sliding wear-reducing aluminum-based bushing (generally made of AlSn20Cu, as shown in fig. 1) is fitted in the cam bearing hole, and the sliding bushing is lubricated by engine oil and friction between the camshaft and the aluminum-based bushing is reduced through the elongated oil passage holes in the upper cover and the base.
However, machining a long and thin oil hole in a steel material increases machining difficulty and machining cost, and a cam bearing seat made of a steel material is heavy, which is not in line with the current trend of weight reduction.
Disclosure of Invention
The embodiment of the invention provides a double overhead cam bearing seat, a manufacturing process, a testing machine and a testing method, and aims to solve the problems that machining difficulty and machining cost are increased when a long and thin oil hole is machined in a steel material, and a cam bearing seat made of the steel material is heavy in the related art.
In a first aspect, a dual overhead cam bearing carrier is provided, comprising: the base is made of aluminum-silicon cast aluminum alloy, and the weight percentage of silicon is 6.5% -11.0%; and the upper cover is arranged on the base.
In some embodiments, the material of the upper cover is 6000 series forged aluminum alloy.
In some embodiments, the upper cover is provided with a threaded mounting hole for mounting the rocker arm shaft, the threaded mounting hole adopts extrusion threads, and a steel wire thread sleeve is arranged in the threaded mounting hole.
In a second aspect, a process for manufacturing the double overhead cam bearing seat as described above is provided, comprising the following steps: selecting 6000 series forged aluminum alloy materials, and sequentially performing die forging, heat treatment and machining to form the upper cover; the base is formed by selecting an aluminum-silicon series casting aluminum alloy material with 6.5-11.0% of silicon by weight percent and sequentially performing casting, heat treatment and machining.
In some embodiments, the heat treatment specifically includes solution treatment and artificial aging.
In some embodiments, the upper cover is provided with a threaded mounting hole for mounting the rocker arm shaft, the threaded mounting hole adopts extrusion threads, and a steel wire thread sleeve is arranged in the threaded mounting hole.
In a third aspect, a sapphire fatigue strength testing machine is provided for performing a sapphire fatigue strength test on the dual overhead cam bearing block, and includes: a main body; the lower fixing block is used for positioning the base test block and is fixed on the main body, and a first groove used for accommodating the base test block is formed in the downward concave mode from the upper surface of the lower fixing block; and the upper fixing block is fixed on the lower fixing block, and meanwhile, the base test block is made of the same material as the base.
In some embodiments, the bottom of the first groove is provided with a cross groove, and the cross groove is used for being matched with a cross rib at the bottom of the base test block to limit the base test block to move in the horizontal direction.
In some embodiments, a second groove is formed by recessing the lower surface of the upper fixing block into the upper fixing block, and when the base test block is installed in the first groove, the base test block and the inner wall surface of the first groove form a cam bearing hole for the camshaft to pass through.
In a fourth aspect, a testing method of the sapphire fatigue strength testing machine is provided, which includes: and when the sapphire fatigue strength testing machine tests that the sapphire fatigue strength of the base test block is more than 3 times of specific pressure, judging that the strength of the base test block meets the design requirement.
The technical scheme provided by the invention has the beneficial effects that:
the embodiment of the invention provides a double overhead cam bearing seat, a manufacturing process, a testing machine and a testing method, wherein the base is made of aluminum-silicon cast aluminum alloy, the weight percentage of silicon is 6.5-11.0%, the manufactured base forms a metallographic structure which takes alpha-Al as a soft base body and eutectic silicon as a hard point, the eutectic silicon is hard, the base can be ensured to have certain wear resistance, the alpha-Al is soft and smooth, the overall hardness of the base can be weakened, the hardness of the base is smaller than that of a camshaft, the friction force generated between the base with low hardness and the camshaft with high hardness is small, the base can achieve the performance basically equivalent to an aluminum-based bushing (AlSn20Cu), and tests prove that the aluminum-based bushing (the material is generally selected from AlSn20Cu) does not need to be added between the base made of the aluminum-silicon cast aluminum alloy and the camshaft, therefore, the base has enough wear resistance, meanwhile, the manufacturing of the aluminum-based bushing is reduced, and materials are saved; the hardness of the base is lower than that of steel, so that the slender oil hole is easy to machine on the base, and the machining cost is reduced; and because the weight of aluminium silicon series casting aluminum alloy is lighter than steel material, the base chooses aluminium silicon series casting aluminum alloy material for use can reduce the total weight of double overhead cam bearing frame.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a schematic metallographic structure of AlSn20 Cu;
fig. 2 is a schematic metallographic structure diagram of a base of a double overhead cam bearing seat according to an embodiment of the present invention;
fig. 3 is a schematic structural view of a double overhead cam bearing seat according to an embodiment of the present invention;
fig. 4 is a schematic partial cross-sectional view of a base test block of a sapphire fatigue strength testing machine according to an embodiment of the present invention;
fig. 5 is a schematic bottom view of a base test block of a sapphire fatigue strength testing machine according to an embodiment of the present invention;
fig. 6 is a schematic cross-sectional view of a lower fixing block of a sapphire fatigue strength testing machine according to an embodiment of the present invention;
FIG. 7 is a schematic cross-sectional view A-A of FIG. 6;
fig. 8 is a schematic cross-sectional view of an upper fixing block of a sapphire fatigue strength testing machine according to an embodiment of the present invention;
fig. 9 is a schematic cross-sectional view of B-B in fig. 8.
In the figure: 1. a lower fixed block; 11. a first groove; 111. a cross groove; 2. testing the base; 21. cross ribs; 22. a third groove; 3. an upper fixed block; 31. a second groove; 4. a base; 41. a lower through hole; 5. an upper cover; 51. an upper through hole; 52. an upper oil duct; 53. and (4) a threaded mounting hole.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
The embodiment of the invention provides a double overhead cam bearing seat, a manufacturing process, a testing machine and a testing method, which can solve the problems that machining difficulty and machining cost are increased when a long and thin oil hole is machined in a steel material, and a cam bearing seat made of the steel material is heavy in the related art.
Referring to fig. 3, a dual overhead cam bearing seat according to an embodiment of the present invention includes: the base 4 is used for being fixed on the top of the cylinder cover; and the upper cover 5 is arranged on the base 4.
Referring to fig. 1 and 2, in some embodiments, the base 4 may be made of an aluminum-silicon cast aluminum alloy, and the silicon may be 6.5-11.0% by weight; for example, the base 4 may be made of a356 or AlSi8Cu3, and the base 4 is made of an aluminum-silicon cast aluminum alloy, so that the base 4 can form a metallographic structure with α -Al as a soft base and eutectic silicon as a hard particle, the eutectic silicon is hard, and the base 4 can have a certain wear resistance, the α -Al is soft and smooth, and can weaken the overall hardness of the base 4, so that the hardness of the base 4 is smaller than that of a camshaft, and a friction force generated between the base 4 with a smaller hardness and the camshaft with a larger hardness is smaller, and the base 4 can achieve a performance substantially equivalent to that of an aluminum-based bushing (AlSn20Cu), so that an aluminum-based bushing is not required to be arranged between the base 4 and the camshaft, and the material is saved; and the use of conventional cast aluminum alloys facilitates commercial material achievement.
Referring to fig. 3, in some alternative embodiments, a lower through hole 41 may be formed in an upper portion of the base 4 and may penetrate the base 4 in a front-rear direction, a cross section of the lower through hole 41 may be in a semi-circular arc shape, and is used for a camshaft for controlling opening and closing of the valve to pass through and support the camshaft, and a lower oil duct may be formed in the base 4 and may be communicated with the lower through hole 41 to lubricate the lower through hole 41, so as to further reduce friction between the camshaft and the base 4.
Referring to fig. 3, in some embodiments, the upper cover 5 may be fixed to the top of the base 4 by bolts, the upper cover 5 may be made of 6000 series forged aluminum alloy, such as 6061 aluminum alloy, the 6000 series forged aluminum alloy is cut and blanked, heated, placed into a forging die, forged into a part blank, then subjected to T6 heat treatment, and finally machined to form the upper cover 5, so that the weight of the machined upper cover 5 is much lighter than that of steel, and the elongation of the machined upper cover 5 can reach 8% or more; an upper through hole 51 penetrating the upper cover 5 from front to back may be formed in the lower portion of the upper cover 5, a cross section of the upper through hole 51 may also be in a semi-circular arc shape, and is used to form a complete cylindrical cam bearing hole in combination with the lower through hole 41, the cam bearing hole is used for the entire camshaft to pass through, the upper cover 5 may also be provided with an upper oil gallery 52 communicated with the upper through hole 51, and is used to provide oil lubrication for the upper through hole 51 and reduce friction between the camshaft and the upper cover 5, the number of the upper oil gallery 52 may be two more than that of the lower oil gallery, and the length of the upper oil gallery 52 may be longer than that of the lower oil gallery; because the base 4 chooses for use aluminium silicon system casting aluminum alloy, the upper cover 5 chooses for use 6000 system forging aluminum alloy, and its weight is all lighter than steel material, can realize the total weight of double overhead cam bearing frame reduces about 50%.
Referring to fig. 3, in some alternative embodiments, the upper cover 5 may further include a threaded mounting hole 53 for mounting a rocker shaft, the threaded mounting hole 53 may be formed by an extrusion thread process, a steel wire thread insert may be disposed in the threaded mounting hole 53, the threaded mounting hole 53 is formed by the extrusion thread process, and the steel wire thread insert is disposed in the threaded mounting hole 53, so that the threaded connection strength between the threaded mounting hole 53 and the rocker shaft may be improved when the elongation of the upper cover 5 reaches 8% or more, and the threaded connection strength may be improved by 10% compared to a cut thread; and by carrying out structural optimization on the rocker arm shaft (that is, by carrying out topological optimization on the shape of the rocker arm shaft part), the stress level of the rocker arm shaft at the position where the rocker arm shaft is installed on the upper cover 5 can be reduced, so that the strength of the upper cover 5 made of 6000-series forged aluminum alloy materials is met.
The embodiment of the invention also provides a manufacturing process of the double overhead cam bearing seat, which comprises the following steps:
step 1: 6000 series forged aluminum alloy materials are selected, and die forging, heat treatment and machining are sequentially carried out to form the upper cover 5.
In some embodiments, in step 1, the selecting a 6000-series forged aluminum alloy material, and performing die forging and heat treatment to form the upper cover 5 may specifically include: cutting and blanking 6000 series forged aluminum alloy, then heating the aluminum alloy, putting the aluminum alloy into a forging die, forging the aluminum alloy into a part blank, then carrying out T6 heat treatment, and finally carrying out machining to form the upper cover 5; wherein, the T6 heat treatment specifically comprises solution treatment and artificial aging; the upper cover 5 processed by the steps can meet the strength requirement of the instantaneous large impact load on the upper cover 5, which is received by the threaded mounting hole 53 of the rocker arm shaft under the exhaust braking working condition, and the elongation of the upper cover 5 can reach more than 8%.
In some alternative embodiments, in step 1, a threaded mounting hole 53 for mounting the rocker arm shaft may be machined in the upper cover 5 by machining, the threaded mounting hole 53 may be formed by an extrusion threading process, and a wire thread insert may be mounted in the threaded mounting hole 53; also, a plurality of upper oil passages 52 may be machined in the upper cover 5 by machining.
Step 2: the base 4 is formed by casting, heat treating and machining an aluminum-silicon cast aluminum alloy material with silicon of 6.5-11.0% by weight in sequence.
In some embodiments, in step 2, the step of forming the base 4 by casting, heat treating and machining the aluminum-silicon cast aluminum alloy material with silicon in a weight percentage of 6.5% to 11.0% may specifically include: forming a part blank by performing low-pressure casting, metal mold gravity casting or tilting casting on an aluminum-silicon series casting aluminum alloy with silicon accounting for 6.5-11.0% by weight, then performing T6 heat treatment, and finally performing machining to form the base 4; the asymmetric characteristic requirements of the double overhead cam bearing seat are met due to the fact that the upper cover 5 and the base 4 are made of different materials and different forming processes.
In some embodiments, in step 2, during the machining process, specifically, the machining process may include forming a plurality of lower oil passages on the base 4.
Referring to fig. 6 and 8, a sapphire fatigue strength testing machine provided for an embodiment of the present invention is used for performing a sapphire fatigue strength test on the dual overhead cam bearing, and includes: a main body; the lower fixing block 1 is fixed on the main body, and the lower fixing block 1 is used for positioning the base test block 2; and an upper fixing block 3 fixed to the lower fixing block 1.
Referring to fig. 4 and 5, in some embodiments, the material of the base test block 2 may be the same as that of the base 4, the external dimension of the base test block 2 may be substantially the same as that of the base 4 of the dual overhead cam bearing seat, the base test block 2 may be substantially rectangular, a cross rib 21 may be convexly disposed at the bottom of the base test block 2, a third groove 22 may be formed by recessing downward from the upper surface of the base test block 2, and a cross section of the third groove 22 may be in a semi-circular arc shape, so as to allow a camshaft to pass through, support the camshaft, and machine the inner wall surface of the third groove 22 according to a standard tile size.
Referring to fig. 6 and 7, in some embodiments, the lower fixing block 1 may be a rectangular parallelepiped, the lower fixing block 1 may be provided with a first groove 11 for accommodating the base test block 2, the first groove 11 may be square, the first groove 11 may be formed by downward recessing from an upper surface of the lower fixing block 1, a size of the first groove 11 is designed corresponding to a size of the base test block 2, so that the base test block 2 can be properly assembled in the first groove 11, a bottom of the first groove 11 corresponding to the cross rib 21 may be provided with a cross groove 111, when the base test block 2 is assembled in the first groove 11, the cross rib 21 may be accommodated in the cross groove 111, so as to limit the base test block 2 from moving in a horizontal direction, and ensure that the base test block 2 does not move left and right or back and forth during a fatigue test, and the cross rib 21 and the cross groove 111 are designed to be in interference fit.
Referring to fig. 8 and 9, in some embodiments, the upper fixing block 3 may also be a rectangular parallelepiped, a second groove 31 may be formed by upwardly recessing a lower surface of the upper fixing block 3, a cross section of the second groove 31 may also be in a semi-circular arc shape, and when the base test block 2 is installed in the first groove 11, the third groove 22 and the second groove 31 together define a cam bearing hole for the camshaft to pass through; through go up fixed block 3 with the structural design of lower fixed block 1 can be with whole base test block 2 install extremely on the lower fixed block 1, can realize right the base of double overhead cam bearing frame carries out sapphire fatigue strength test, has solved the unsuitable preparation of block material and has become the problem that standard tile passes through DP sapphire fatigue testing machine and detects.
The embodiment of the invention also provides a test method of the sapphire fatigue strength testing machine, which comprises the following steps: when the sapphire fatigue strength testing machine tests that the sapphire fatigue strength of the base test block 2 is greater than 3 times of specific pressure, the strength of the base test block 2 is judged to meet the design requirements, wherein the specific pressure specifically refers to the force borne by a unit area on a bearing bush, in the embodiment, a certain heavy-duty diesel engine is preferably selected, the maximum specific pressure of a cam bearing hole of the heavy-duty diesel engine is 14Mpa, the sapphire fatigue strength of an A356 alloy block material prepared through a low-pressure casting process is 55Mpa, the sapphire fatigue strength of an AlSi8Cu3 alloy block material prepared through the low-pressure casting process is 70Mpa, and the sapphire fatigue strengths of the A356 alloy block material and the AlSi8Cu3 alloy block material are judged to meet the design requirements according to the testing method.
The principles of the double overhead cam bearing seat, the manufacturing process, the testing machine and the testing method provided by the embodiment of the invention are as follows:
because the base 4 is made of aluminum-silicon cast aluminum alloy and the weight percentage of silicon is 6.5% -11.0%, the manufactured base 4 forms a metallographic structure which takes alpha-Al as a soft matrix and eutectic silicon as hard particles, the eutectic silicon is hard, the base 4 can be ensured to have certain wear resistance, the alpha-Al is soft and smooth, the overall hardness of the base 4 can be weakened, the hardness of the base 4 is smaller than that of a camshaft, the friction force which can be generated between the base 4 with the smaller hardness and the camshaft with the larger hardness is smaller, the base 4 can achieve the performance which is basically equivalent to an aluminum-based bushing (AlSn20Cu), and tests prove that the aluminum-silicon cast aluminum alloy is adopted to manufacture the base 4 and the camshaft without adding the aluminum-based bushing (the material is generally selected from AlSn20Cu), the base 4 has enough wear resistance, meanwhile, the manufacturing of an aluminum-based bushing is reduced, and materials are saved; and because the hardness of the base 4 is lower than that of steel, a slender oil hole is easier to process on the base 4, and the processing cost is reduced; and because the weight of aluminium silicon series casting aluminum alloy is lighter than steel material, base 4 chooses for use aluminium silicon series casting aluminum alloy material can reduce the total weight of double overhead cam bearing frame.
In the description of the present invention, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present invention. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
It is to be noted that, in the present invention, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The foregoing are merely exemplary embodiments of the present invention, which enable those skilled in the art to understand or practice the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended 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 (10)

1. The utility model provides a two overhead cam bearing seats which characterized in that, it includes:
the base (4), the material of the said base (4) is aluminium silicon series casting aluminium alloy, and the weight percent of silicon is 6.5% -11.0%;
and the upper cover (5) is arranged on the base (4).
2. A double overhead cam carrier as set forth in claim 1, wherein:
the upper cover (5) is made of 6000 series forged aluminum alloy.
3. A double overhead cam carrier as set forth in claim 2, wherein:
the upper cover (5) is provided with a threaded mounting hole (53) for mounting a rocker shaft, the threaded mounting hole (53) adopts extrusion threads, and a steel wire thread insert is arranged in the threaded mounting hole (53).
4. A process for manufacturing a double overhead cam carrier housing according to claim 1, comprising the steps of:
selecting 6000 series forged aluminum alloy materials, and sequentially performing die forging, heat treatment and machining to form the upper cover (5);
the base (4) is formed by selecting an aluminum-silicon series casting aluminum alloy material with 6.5-11.0% of silicon by weight and sequentially carrying out casting, heat treatment and machining.
5. The manufacturing process of claim 4, wherein:
the heat treatment specifically includes solution treatment and artificial aging.
6. The manufacturing process of claim 4, wherein:
the upper cover (5) is provided with a threaded mounting hole (53) for mounting a rocker shaft, the threaded mounting hole (53) adopts extrusion threads, and a steel wire thread insert is arranged in the threaded mounting hole (53).
7. A sapphire fatigue strength tester for performing a sapphire fatigue strength test on the double overhead cam bearing housing of claim 1, characterized in that it comprises:
a main body;
the lower fixing block (1) is used for positioning the base test block (2), the lower fixing block (1) is fixed on the main body, and a first groove (11) used for accommodating the base test block (2) is formed in a downward concave mode from the upper surface of the lower fixing block (1);
the upper fixing block (3) is fixed on the lower fixing block (1); at the same time, the user can select the desired position,
the base test block (2) is made of the same material as the base (4).
8. The sapphire fatigue strength testing machine of claim 7, wherein:
the bottom of the first groove (11) is provided with a cross groove (111), and the cross groove (111) is used for being matched with a cross rib (21) at the bottom of the base test block (2) to limit the movement of the base test block (2) in the horizontal direction.
9. The sapphire fatigue strength testing machine of claim 7, wherein:
form second recess (31) from the lower surface of last fixed block (3) to last fixed block (3) indent is established, when base test block (2) install to in first recess (11), base test block (2) with the internal face of first recess (11) forms the cam bearing hole that supplies the camshaft to pass.
10. A method for testing the sapphire fatigue strength tester as claimed in claim 7, comprising:
and when the sapphire fatigue strength testing machine tests that the sapphire fatigue strength of the base test block (2) is more than 3 times of specific pressure, judging that the strength of the base test block (2) meets the design requirement.
CN202010768648.9A 2020-08-03 2020-08-03 Double-overhead cam bearing seat, manufacturing process, testing machine and testing method Pending CN112065862A (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1384072A (en) * 1971-09-09 1975-02-19 Vandervell Products Ltd Bearings
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Publication number Priority date Publication date Assignee Title
GB1384072A (en) * 1971-09-09 1975-02-19 Vandervell Products Ltd Bearings
US4754729A (en) * 1985-10-11 1988-07-05 Honda Giken Kogyo Kabushiki Kaisha Camshaft support assembly for valve operating mechanism in an internal combustion engines
US6715458B1 (en) * 2000-08-03 2004-04-06 General Motors Corporation Engine block crankshaft bearings
CN202301467U (en) * 2011-08-07 2012-07-04 十堰艾帝迩科技有限公司 Rear bearing base of transmission case second shaft
CN105081275A (en) * 2015-09-23 2015-11-25 辽宁工程技术大学 Method for preparing graded pressurization liquid forging aluminum alloy engine cylinder cover
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Application publication date: 20201211