KR20140049074A - Method for manufacturing camshaft for internal combustion engine - Google Patents

Method for manufacturing camshaft for internal combustion engine Download PDF

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Publication number
KR20140049074A
KR20140049074A KR1020147007129A KR20147007129A KR20140049074A KR 20140049074 A KR20140049074 A KR 20140049074A KR 1020147007129 A KR1020147007129 A KR 1020147007129A KR 20147007129 A KR20147007129 A KR 20147007129A KR 20140049074 A KR20140049074 A KR 20140049074A
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Prior art keywords
cooling
camshaft
internal combustion
cam shaft
cooling treatment
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KR1020147007129A
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Korean (ko)
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KR101539314B1 (en
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다카시 후나바시
슌스케 다케구치
?스케 다케구치
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닛폰 피스톤 린구 가부시키가이샤
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    • 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
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/02—Valve drive
    • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
    • 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
    • C21D9/30—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for crankshafts; for camshafts
    • 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
    • F16C3/00—Shafts; Axles; Cranks; Eccentrics
    • F16C3/02—Shafts; Axles
    • F16C3/023—Shafts; Axles made of several parts, e.g. by welding

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

Abstract

It is an object of the present invention to provide a method for manufacturing a cam shaft obtained by stabilizing an effect of improving wear characteristics such as fitting resistance and scuffing resistance. In order to achieve this object, a heat treatment step of heating a cam shaft formed by assembling a cam piece of sintered material to a shaft body of a steel pipe to a sintering temperature by heat treatment, and a heat treated cam shaft by a cooling treatment apparatus. In the method for manufacturing a cam shaft for an internal combustion engine including a cooling treatment step of cooling by means of the above, in the cooling treatment step, a slow cooling is performed after arranging the cam shaft in a state surrounded by graphite plates provided around the inside of the cooling treatment apparatus. It is assumed that cooling is carried out in a two-step process of a first-stage cooling treatment step and a second-stage cooling treatment step in which the cooling gas injected into the cooling treatment apparatus is circulated by a fan to perform quenching.

Description

Manufacturing Method of Camshaft for Internal Combustion Engine {METHOD FOR MANUFACTURING CAMSHAFT FOR INTERNAL COMBUSTION ENGINE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a cam shaft for an internal combustion engine, and more particularly, to a method for manufacturing a cam shaft in which a cam lobe made of sintered alloy powder and a shaft of a steel are formed by diffusion bonding.

Conventionally, a cast iron cam shaft integrally formed by casting, a sintered cam shaft in which a cam lobe of a sintered material is joined to a steel shaft, and the like are used as a cam shaft for an internal combustion engine. Here, cast iron camshafts are relatively inexpensive but difficult to reduce in weight, and there are manufacturing problems such as difficulty in forming cam portions with high precision. In addition, the cast iron camshaft can only use a castable material, and it is difficult to make a cam part excellent in wear resistance. Therefore, in the case of cast iron camshafts, wear characteristics such as fitting resistance and scuffing resistance are inferior, and it is difficult to cope with the increase in performance and light weight of the internal combustion engine. On the other hand, the sintered camshaft can select an alloy component according to the performance calculated | required by a cam, and can hollow a shaft. Therefore, the sintered cam shaft in which the cam lobe of the sintered material is joined to the forced shaft is a lightweight cam shaft that has high wear resistance and can withstand high surface pressure and high load, and can be suitably used for an internal combustion engine requiring high performance and light weight. have.

For example, Patent Document 1 (Japanese Patent Laid-Open No. 2001-271909) discloses a shaft and a prefabricated cam which are preferably used for a prefabricated camshaft formed by diffusion bonding a cam lobe made of sintered alloy powder and a shaft made of steel. A method for producing a shaft is disclosed. Specifically, the cam shaft of Patent Literature 1 includes a shaft processed by spherical annealing of a high carbon chromium bearing steel material, and then drawn and processed to a predetermined dimension. And a sintered alloy powder are pressed to produce a cam lobe formed in a compacted molded body having a predetermined size, the cam lobe is assembled to the shaft, and these are produced by diffusion bonding. Further, Patent Document 1, in the manufacture of prefabricated camshaft, the cooling after having passed through the sintering furnace, in particular A 1 by the cooling rate of the transformation point near steps in 10 ℃ / min ~ 20 ℃ / minute roughness, fine It is disclosed that the base structure of the pearlite main body including the precipitated carbide (see paragraph).

Patent Document 1: Japanese Patent Application Laid-Open No. 2001-271909

However, Patent Document 1 does not disclose any method of cooling the entire circumference of the camshaft at the same speed uniformly in the cooling step of the camshaft. If the entire circumference of the camshaft is not cooled uniformly at the same speed, nonuniformity in mechanical properties occurs in a portion of the camshaft, resulting in deterioration of quality. Moreover, the sintering furnace used for manufacture of a camshaft generally includes the sintering apparatus which sinters a camshaft, and the cooling apparatus which cools the sintered camshaft. And in these sintering apparatuses and a cooling apparatus, in order to process, for example, a camshaft is installed horizontally, and a plurality of mounting plates mounted in multiple numbers are mounted in a jig in the state which piled up several steps, and it conveys sequentially, and a process is carried out. Is done. When the sintered camshaft is cooled from a temperature higher than the sintering temperature, in many cases, forced cooling is performed by circulating the cooling gas in the cooling processing chamber of the cooling apparatus. Individual differences occur in the cooling rate on the outside.

As mentioned above, this invention does not produce an individual difference in the cooling speed of a camshaft according to the mounting position in a cooling apparatus, cools the whole periphery of a camshaft uniformly, and wear characteristics, such as fitting resistance and scuffing resistance, are made. It is an object of the present invention to provide a method for producing a cam shaft for an internal combustion engine, in which the improvement effect of the present invention is stably obtained.

Therefore, as a result of intensive studies, the present inventors have come to solve the above-mentioned problems by satisfying predetermined conditions for the cooling treatment after the sintering of the camshaft. EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated.

The manufacturing method of the camshaft for internal combustion engines which concerns on this invention is the heat processing process of heating the camshaft formed by assembling the campiece of a sintering material to the shaft main body of a steel pipe to a sintering temperature with a heat processing apparatus, and a heat processing In the method for manufacturing a cam shaft for an internal combustion engine including a cooling treatment step of cooling the camshaft by a cooling treatment device, in the cooling treatment step, the camshaft is arranged in a state surrounded by a graphite plate provided around the inside of the cooling treatment device. After that, a two-step process of a first stage cooling treatment step of performing slow cooling and a second stage cooling treatment process of circulating a cooling gas injected into the cooling treatment apparatus by a fan to perform quenching. It characterized by cooling to.

In the manufacturing method of the cam shaft for internal combustion engines which concerns on this invention, it is preferable to heat at the temperature which the said heat processing process controlled the sintering temperature to 900 degreeC-1200 degreeC in carrying out sintering.

In the manufacturing method of the cam shaft for internal combustion engines which concerns on this invention, it is preferable that the said 1st step cooling process cools between 700 degreeC-900 degreeC at a cooling rate of 10 degreeC / min-30 degreeC / min.

In the method for manufacturing a cam shaft for an internal combustion engine according to the present invention, in the second step cooling treatment step, a temperature range of 30 ° C./min to 300 ° C./min is set in the following temperature range from the temperature after the completion of the first step cooling treatment step. It is preferable to cool at a speed of.

In the manufacturing method of the camshaft for internal combustion engines which concerns on this invention, it is preferable at the said cooling process process to perform cooling processing in the state which mounted a plurality of the said internal combustion engine camshaft to the mounting jig | tool piled up in multiple stages.

According to the manufacturing method of the camshaft for internal combustion engines which concerns on this invention, a cooling process is performed around the sintered camshaft arrange | positioned in a cooling apparatus in the state enclosed by graphite plate, and the improvement of abrasion characteristics, such as fitting resistance and scuffing resistance, is improved. It is possible to provide a cam shaft for an internal combustion engine that has a stable effect.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front view exemplified for explaining the continuous sintering furnace used in the method for manufacturing a cam shaft for an internal combustion engine according to the present invention.
2 is a cross-sectional view taken along line AA 'of FIG.
3 is an explanatory view from a front cross section for explaining the cooling device of FIG. 1.

EMBODIMENT OF THE INVENTION Preferred embodiment of the manufacturing method of the camshaft for internal combustion engine which concerns on this invention is described in detail below with reference to drawings.

Method for producing a cam shaft for an internal combustion engine according to the present invention:

A heat treatment step of heating a camshaft formed by assembling a cam piece of sintered material to a shaft body of a steel pipe to a sintering temperature by a heat treatment device, and a cooling treatment of cooling the heated camshaft by a cooling treatment device. In the method for manufacturing a camshaft for an internal combustion engine comprising a step, in the cooling treatment step, after arranging the camshaft in a state surrounded by graphite plates provided around the inside of the cooling treatment apparatus, a first step of performing slow cooling The cooling treatment process and the cooling gas injected into the said cooling treatment apparatus are circulated by a fan, and it cooled by the process of two steps of the 2nd stage cooling treatment process which performs quenching. It is characterized by the above-mentioned.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view for demonstrating the continuous sintering furnace used by the manufacturing method of the camshaft for internal combustion engines which concerns on this invention. 2 is sectional drawing A-A 'of FIG. 3 is explanatory drawing from the front cross section for demonstrating the cooling device of FIG. As illustrated in FIG. 1, the continuous sintering furnace 1 used in the method for producing an internal combustion engine cam shaft according to the present invention includes a vacuum waiting chamber 2, a preheating device 3 that performs dewaxing, and sintering. The sintering apparatus 4 and the cooling apparatus 5 can be comprised. In the continuous sintering furnace 1 shown in FIG. 1, the inlet door 11 for carrying the camshaft and the exit door 12 for carrying out the camshaft after the treatment are respectively opened and closed by the opening and closing devices 13 and 14. It is designed to drive up and down. Incidentally, the reference numerals 15 to 20 in the drawings also show opening and closing devices, respectively, and the lifting and lowering driving of each door (not shown) for dividing each chamber is performed. And the conveyance roller 21 for conveying the camshaft W is provided over the full length of the continuous sintering furnace 1.

Here, the conveyance roller 21 forms a cylinder shape, and is arrange | positioned in the furnace body through the inlet door 11 and the outlet door 12 so that the axis | shaft of the said conveyance roller 21 may be parallel to a horizontal and front-back direction. Such conveying rollers 21 are provided at the same height in multiple numbers at intervals narrower than the conveyance direction length of the jig J which loaded the camshaft W. As shown in FIG. In addition, the conveyance rollers 21 are rotatably supported around the axis of the roller, respectively. For example, it can be set as the structure which all the rollers rotate in the same direction and the same rotational speed by the chain (not shown) using a motor (not shown) as a power source. In the continuous sintering furnace 1 used in the present invention, the camshaft W is mounted on the conveying roller 21, and the heat treatment is performed while the camshaft W is gradually moved forward by the rotation of the conveying roller 21. And a method of performing cooling treatment.

Based on the above, the heat processing process and cooling processing process in this invention are demonstrated concretely below. First, the heat processing process in the manufacturing method of the camshaft for internal combustion engines which concerns on embodiment of this invention is demonstrated. In the heat treatment process of this invention, the camshaft W is first carried in through the inlet opening with the inlet door 11 of the continuous sintering furnace 1, and is carried in in the continuous sintering furnace 1 inside. And the carried camshaft W is carried in the preheating heating chamber 3 by rotation of the conveyance roller 21 which is a conveying means, and is heated to 500 degreeC-700 degreeC, for example, and evaporates the wax previously added. Remove Then, the camshaft W subjected to the treatment in the preliminary heating device 3 is carried in the sintering device 4, heated to a sintering temperature of 900 ° C. to 1200 ° C., and sintered. The camshaft W after completion of the sintering process is cooled in the cooling device 5 and carried out from the exit door 12 of the continuous sintering furnace 1.

And the preheating apparatus 3 and the sintering apparatus 4 with which the continuous sintering furnace 1 used by the heat processing process of this invention and the sintering apparatus 4 are a heat source (not shown) on four surfaces of the camshaft W up, down, left, and right. Is installed). In the continuous sintering furnace 1 used in the heat treatment step of the present invention, a roller hearth type is employed to directly transfer the heat of the heat source disposed on the bottom surface between adjacent rollers to the camshaft W. I can tell you. As a result, according to the continuous sintering furnace 1 used in the heat processing process of this invention, it can heat-process uniformly about all the cam shafts W mounted on jig J, and it is the range of +/- 10 degreeC with respect to sintering temperature. It becomes possible to perform temperature control at. Therefore, the continuous sintering furnace 1 used in the heat processing process of this invention is a batch type which employ | adopted the system which heat-processes sequentially, for example by moving the carriage which loaded several camshafts. type) The sintering time can be shortened while the treatment can be performed similarly to the sintering furnace.

Next, the cooling process in the manufacturing method of the camshaft for internal combustion engines which concerns on embodiment of this invention is demonstrated. As shown in Fig. 2 and Fig. 3, the cooling device 5 used in the cooling treatment step of the present invention is disposed continuously on the cam shaft W carry-in and out side of the heat treatment device in the continuous sintering furnace 1, The carrying-in door 59 which carries in the camshaft W and the exit door 12 which carries out the camshaft W are comprised, and are closed, and by closing these doors, the inside of the cooling apparatus 5 can be sealed. It has a structure. The cooling apparatus 5 of this invention can perform a cooling process uniformly with respect to all the camshaft W mounted on the jig J by cooling in the state which the inside was pressurized. And the cooling apparatus 5 used by this invention is equipped with the structure which provided the board 51 made of graphite so that all the camshafts W mounted on the jig J may be provided, and the graphite board 51 at the time of a cooling process is carried out. Each camshaft can be cooled at a uniform speed without an individual difference, without being influenced by the mounting position on the jig J of the camshaft W by the heat insulation and heat dissipation effect by it.

As described above, the cooling device 5 used in the cooling treatment step of the present invention performs the cooling treatment with the graphite plate 51 made of graphite so as to surround all the cam shafts W mounted on the jig J. I adopt the method. Here, graphite means the lump of carbon produced by high temperature heat processing called graphitization. The graphite material is porous, and the air present therein absorbs heat to function as a heat insulating material, and the graphite itself has a good thermal conductivity (high thermal conductivity), so that the graphite material can be suitably used for heat dissipation and cooling pallets. Can be. That is, the graphite plate 51 surrounding the camshaft W in the cooling device 5 used in the cooling treatment process of the present invention also acts as a heat storage body, and at the same time prevents partial supercooling of the camshaft W. By suppressing the heat radiation from the cam shaft W by the temperature rising of the graphite plate itself, the temperature difference by the arrangement position of the cam shaft W can be made small. As a result, according to the cooling device 5 used in the cooling treatment process of this invention, cooling can be performed at a uniform speed with respect to all the cam shafts W in the cooling treatment chamber 52, and the part of the cam shaft W The non-uniformity of the mechanical properties in the part does not lead to degradation of product quality. In addition, since the graphite plate is porous and has air permeability, it is considered that such an effect can be obtained, and in view of this point, the graphite plate can also be substituted as a ceramic plate having a porous and excellent thermal conductivity.

In addition, as shown in FIG. 2, the fan 53 is installed inside the cooling device 5 used in the cooling treatment step of the present invention, and is rotated by a motor stored in the fan drive device M, thereby showing the drawing. Cooling gas introduced from the cooling gas inlet which has not been made can be circulated in the cooling processing chamber 52. In addition, in the cooling device 5 used in the cooling treatment process of this invention, the heat exchanger 55 which distribute | distributes and heat-exchanges the refrigerant | coolant introduce | transduced from the refrigerant | coolant introduction tube 56, and is drawn out from the refrigerant | coolant lead-out tube 57 is cooled. It can be installed in the processing chamber 52. In the cooling apparatus 5 used in the cooling treatment process of this invention, when it is set as such a structure, whenever the cooling gas or air which circulates in the cooling processing chamber 52 contacts the heat exchanger 55, it is cooled and quenched. The process can be performed. In the cooling processing chamber 52, a rectifying plate 58 for efficiently convection circulating the introduced cooling gas is provided. And the fan 53 can change the circulation speed at the time of circulating a cooling gas. For example, the fan 53 can be controlled between fan rotation speeds of 20 Hz to 60 Hz from fan rotation speed 0 Hz in a state in which cooling gas is not circulated. In addition, in FIG. 2, although the fan 53 is arrange | positioned so that a cooling gas may be sent from the side, it is not limited to this position. Moreover, what pressurized nitrogen, argon, helium, etc. can be used for the cooling gas used by the cooling process of this invention, for example.

The cooling device 5 used in the cooling treatment process of the present invention can impart desired mechanical properties to the camshaft by employing the above-described method. Moreover, the manufacturing method of the camshaft for internal combustion engines which concerns on this invention employ | adopts a two-stage cooling system in a cooling treatment process, and is excellent in abrasion characteristics, such as pitting resistance and scuffing resistance. when the base structure of pearlite (pearlite) subjects, and at a temperature in the vicinity before and after the a 1 transformation point so as to change the cooling rate of the camshaft. For example, in the cooling treatment process of the present invention, by setting the fan rotation speed to be 20 Hz to 30 Hz just before passing the temperature near the A 1 transformation point, by slow cooling, the camshaft caused by the nonuniformity of the temperature distribution occurs. inhibiting the modification, the number of revolutions of the fan after passing through the temperature in the vicinity of a 1 transformation point can be reduced to shorten the cycle time by quenching by setting such that the 30Hz ~ 60Hz.

Moreover, in the manufacturing method of the camshaft for internal combustion engines of this invention, it is preferable to heat at the temperature which the sintering temperature controlled to 900 degreeC-1200 degreeC in the heat processing process in carrying out sintering.

In the heat treatment process of the present invention, the sintering temperature performed on the sintering camshaft is slightly different depending on the component composition of the sintering alloy powder to be used, but is usually a temperature range between 900 ° C and 1200 ° C. Therefore, in the sintering apparatus 4 used in the heat processing process of this invention, the inside is made into a vacuum state, it energizes each heat source provided in the inside of an apparatus, and the temperature in a furnace is between 900 degreeC-1200 degreeC. By maintaining at a predetermined temperature of, the camshaft W is sintered. In addition, when the sintering temperature is 900 ° C. or less, since the time spent on diffusion bonding of the metal particles or diffusion bonding becomes insufficient, the quality of the camshaft W cannot be stabilized. And in the manufacturing method of the camshaft for internal combustion engines which concerns on this invention, by employing a roller hearth type continuous furnace, as mentioned above, the heat source which becomes a heat source in the upper, lower, left, and right sides of the camshaft W is installed in a heat processing process. Therefore, temperature control can be performed in the range of ± 10 ° C with respect to the sintering temperature regardless of the mounting position of the cam shaft W. Therefore, according to the manufacturing method of the camshaft for internal combustion engines which concern on this invention, the diffusion bonding of the shaft and cam lobe which comprise a camshaft in sintering process can be performed suitably.

Moreover, in the manufacturing method of the camshaft for internal combustion engines which concerns on this invention, it is preferable that a 1st step cooling process cools between 700 degreeC-900 degreeC at a cooling rate of 10 degreeC / min-30 degreeC / min. . If the cooling rate is less than 10 ° C / min, cooling is too slow, the crystal structure is pearlized, and the strength is lowered. On the other hand, if the cooling rate exceeds 30 ° C / min, the crystal structure It is not preferable because the amount of retained austenite tends to be excessive and the toughness tends to decrease.

The manufacturing method of the camshaft for internal combustion engines which concerns on this invention cools a camshaft by cooling between 700 degreeC-900 degreeC at a cooling rate of 10 degreeC / min-30 degreeC / min in a 1st stage cooling treatment process. It is possible to suppress the occurrence of deformation due to. Therefore, according to the manufacturing method of the camshaft for internal combustion engine which concerns on this invention, after cooling the camshaft W, it is not necessary to perform machining etc. so that it may become a predetermined dimension, and manufacturing cost can be reduced. The temperature at 700 ° C to 900 ° C includes the temperature near the A 1 transformation point described above, and the temperature changes to a pearlite structure when the austenitic steel or iron-based sintered material is slowly cooled (cooling rate: about 20 ° C / min). Area. The cooling device 5 used in the cooling treatment step of the present invention, as described above, performs the cooling treatment with the graphite plate 51 installed so as to surround all of the cam shafts W mounted on the jig J. As a result of the conventional cooling treatment, the camshaft can be cooled uniformly in a short time, unlike the case where the atmosphere in the cooling device is cooled in a state in which natural convection is hardly applied. Therefore, according to the manufacturing method of the camshaft for internal combustion engines which concern on this invention, the camshaft excellent in wear characteristics, such as fitting resistance and scuffing resistance, can be obtained in a short time.

Moreover, in the manufacturing method of the camshaft for internal combustion engines which concerns on this invention, in a 2nd step cooling processing process, the following temperature range is moved to the following temperature range from the temperature after completion | finish of a 1st step cooling processing process 30 degreeC / min-300 degreeC / min. It is preferable to cool at a speed of.

In the method of manufacturing the camshaft for an internal combustion engine according to the present invention, in the second stage cooling treatment step, a temperature range of 600 ° C. or less from 600 ° C. having a low risk of cooling unevenness or deformation occurs at a cooling rate of 30 ° C./min to 300 ° C./min. By cooling at the speed of, the cooling treatment time can be significantly shortened. As described above, the cooling device 5 used in the cooling treatment step of the present invention includes a heat exchanger 57 in the cooling treatment chamber 52 and a fan 53 in order to improve the cooling efficiency. It is also possible to further improve the cooling efficiency by increasing the rotational speed of the gas to maximize the circulation speed of the cooling gas in the cooling processing chamber 52. Also in this case, the cooling apparatus 5 used in the cooling process of this invention performs cooling process in the state which installed the graphite plate 51 made of graphite so that all the cam shafts W mounted in the jig J may be enclosed. By adopting the system, it is possible to cool all cam shafts at a uniform speed. In the case of the camshaft for the internal combustion engine, the following temperature range is cooled from 600 ° C at a cooling rate of 30 ° C / min to 300 ° C / min until the temperature of the camshaft for the internal combustion engine reaches 200 ° C. Even if it cools, there is no influence on product quality, but manufacturing cost is reduced rather.

Moreover, in the manufacturing method of the camshaft for internal combustion engines which concerns on this invention, in a cooling process, it is preferable to perform cooling processing in the state which mounted a plurality of internal combustion engine camshafts in the mounting jig | tool piled up in multiple stages.

In the heat treatment process and the cooling treatment process of the present invention, as shown in FIG. 3, for example, the cam shaft W is set horizontally and horizontally so that the heat treatment and the cooling treatment of the sintered cam shaft are improved. It is preferable to process the mounting plate mounted in plural at once in the state which laminated | stacked plural steps. However, when a plurality of cam shafts W are processed at the same time, a temperature difference tends to occur depending on the mounted position, and in order to obtain desired mechanical properties, it is necessary to cool the entire circumference of the cam shaft W at the most uniform speed in the cooling process. Do. However, as described above, according to the cooling apparatus 5 used in the cooling treatment step of the present invention, since the graphite plate can be arranged on the bottom surface side at the time of cooling treatment by adopting the roller hearth type, It becomes possible to control the cooling speed of the camshaft W without individual difference.

As mentioned above, according to the manufacturing method of the camshaft for internal combustion engines which concerns on this invention, many camshafts W which are excellent in abrasion characteristics, such as pitch resistance and scuffing resistance, can be manufactured by one process, and the manufacturing cost can be reduced. can do.

[Industrial Availability]

As mentioned above, according to the manufacturing method of the camshaft for internal combustion engines which concern on this invention, the camshaft provided with especially high mechanical strength can be provided stably. As a result, the camshaft produced by the manufacturing method of this invention can reduce the diameter of a shaft, or can make thickness thin in a hollow shaft, and achieves the weight reduction, maintaining the outstanding durability performance. You can do it. Moreover, according to the manufacturing method of the camshaft which concerns on this invention, since the cooling process which requires comparatively time rather than heat processing can be shortened, each process can be advanced efficiently. In other words, the continuous sintering furnace 1 employs the manufacturing method of the camshaft for internal combustion engine which concerns on this invention, and the camshaft is carried out by the conveyance roller 21 so that each processing apparatus 2-5 may be moved sequentially. When the W is moved (arrow direction shown in Fig. 1), the cam shaft W can be moved efficiently. As a result, according to the manufacturing method of the camshaft for internal combustion engine which concerns on this invention, since reduction of a manufacturing cost can be aimed at, other sliding moving elements used for an internal combustion engine, for example, where high quality and high mechanical strength are calculated | required. It is also possible to employ preferably.

1: Continuous Sintering Furnace
2: waiting room
3: preheating device
4: sintering device
5: cooling system
11: entrance door
12: exit door
21: conveying roller
51: graphite plate
52: cooling treatment chamber
53: fan
55: heat exchanger
56: refrigerant introduction pipe
57: refrigerant refrigerant pipe
58: rectification plate
J: jig
M: motor unit for fan drive
W: Camshaft

Claims (5)

A heat treatment step of heating a cam shaft formed by assembling a cam piece of sintered material to a shaft body of a steel pipe to a sintering temperature by a heat treatment device, and a heat treated cam shaft is cooled. In the manufacturing method of the cam shaft for internal combustion engines containing the cooling process process cooled by a processing apparatus,
In the cooling treatment step, after arranging the cam shaft in a state surrounded by a graphite plate provided around the inside of the cooling treatment apparatus, a first stage cooling treatment step of performing slow cooling and cooling injected into the cooling treatment apparatus. The gas is circulated by a fan and cooled in a two step process of a second step cooling treatment step in which quenching is performed.
Method for producing a cam shaft for an internal combustion engine, characterized in that. The method of claim 1,
The said heat treatment process is a manufacturing method of the camshaft for internal combustion engines which heats at the temperature controlled by 900 degreeC-1200 degreeC in sintering. 3. The method according to claim 1 or 2,
The said 1st step cooling treatment process cools the camshaft for internal combustion engines between 700 degreeC-900 degreeC by the cooling rate of 10 degreeC / min-30 degreeC / min. 4. The method according to any one of claims 1 to 3,
The second stage cooling treatment step produces a cam shaft for an internal combustion engine that cools the following temperature ranges at a cooling rate of 30 ° C./minute to 300 ° C./minute from the temperature after the first step cooling treatment step is completed. Way. 5. The method according to any one of claims 1 to 4,
In the cooling treatment step, the internal combustion engine camshaft manufacturing method is performed by cooling the plurality of the camshaft for the internal combustion engine in a mounting jig stacked in a plurality of stages.
KR1020147007129A 2011-09-30 2012-09-28 Method for manufacturing camshaft for internal combustion engine KR101539314B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JPPCT/JP2011/072597 2011-09-30
PCT/JP2011/072597 WO2013046445A1 (en) 2011-09-30 2011-09-30 Method for manufacturing internal combustion engine cam shaft
PCT/JP2012/075109 WO2013047761A1 (en) 2011-09-30 2012-09-28 Method for manufacturing camshaft for internal combustion engine

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Publication Number Publication Date
KR20140049074A true KR20140049074A (en) 2014-04-24
KR101539314B1 KR101539314B1 (en) 2015-07-24

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