JP3396261B2 - Method of manufacturing camshaft for internal combustion engine - Google Patents
Method of manufacturing camshaft for internal combustion engineInfo
- Publication number
- JP3396261B2 JP3396261B2 JP19510393A JP19510393A JP3396261B2 JP 3396261 B2 JP3396261 B2 JP 3396261B2 JP 19510393 A JP19510393 A JP 19510393A JP 19510393 A JP19510393 A JP 19510393A JP 3396261 B2 JP3396261 B2 JP 3396261B2
- Authority
- JP
- Japan
- Prior art keywords
- cam
- shaft
- camshaft
- drive shaft
- combustion engine
- 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.)
- Expired - Fee Related
Links
- 238000002485 combustion reaction Methods 0.000 title claims description 9
- 238000004519 manufacturing process Methods 0.000 title claims description 9
- 238000003780 insertion Methods 0.000 claims description 11
- 230000037431 insertion Effects 0.000 claims description 11
- 230000005540 biological transmission Effects 0.000 claims description 10
- 238000000034 method Methods 0.000 claims description 5
- 238000001816 cooling Methods 0.000 claims 1
- 238000003825 pressing Methods 0.000 claims 1
- 238000010273 cold forging Methods 0.000 description 9
- 239000000463 material Substances 0.000 description 9
- 238000003466 welding Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000003672 processing method Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005219 brazing Methods 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Landscapes
- Valve-Gear Or Valve Arrangements (AREA)
Description
【発明の詳細な説明】
【０００１】
【産業上の利用分野】本発明は、内燃機関のカム軸の製
造方法に関する。
【０００２】
【従来の技術】図３に第１従来例のカム軸の正面図を示
した。クランク軸に連動させるための伝動歯車もしくは
スプロケット（以後、適宜歯車と略称する）と、吸排気
弁を開閉させるためのカムを同軸上に固定した状態で形
成するカム軸は、鍛造もしくは鋳造によって成形された
素材を用い、図に示したようにジャーナル部１０４、カ
ム部１０３、歯車部１０１等を機械加工してカム軸１０
７を一体形成するか、歯車のみは軸部１０２と別個の素
材を機械加工し、キー等により軸部１０２に固定してい
た。しかしながら、このような従来の手段には、次のよ
うな問題点がある。
（１）カム軸１０７の材料として、カム部１０３、歯車
部１０１の耐摩耗の要求に適合する高級な材料が要求さ
れる。
（２）ジャーナル部１０４、カム部１０３、歯車部１０
１等を機械加工により製品化するために加工設備及び加
工工数に、多大の費用が必要となる。
【０００３】次に第２従来例として、前記の問題点を解
決したカム軸（実開平０２−１５７６３７号公報に示さ
れた考案）の縦断面図を図４に示した。図に示されるよ
うにカム軸２０７は、軸２０２、カム２０３、歯車２０
１、スラスト座金２０５から構成される。軸２０２は、
カム軸２０７のジャーナル部として使用され、引抜き棒
鋼にセンタレス研削したもの等が用いられる。前記引抜
き棒鋼の代用として管材を用いることもできる。カム２
０３には、機械加工品に替えて焼結材を用いることもあ
る。歯車２０１は、機械加工品が用いられるが、板金成
形品、樹脂等を用いることも可能である。軸２０２のサ
イド寸法を決めるために用いるスラスト座金２０５に
は、板金成形品を用いる。軸２０２にカム２０３、歯車
２０１、スラスト座金２０５を圧入することによりカム
軸２０７を構成するが、圧入に替えて、レーザ溶接また
はろう付けによって一体化することも可能である。
【０００４】図４に示したカム軸２０７は構成部分を全
て別体として形成し、その後の工程で一体に結合して構
成することにより、次の効果が得られる。
（１）構成部品のそれぞれに適合する材料を選定でき、
材料費の低減が可能である。
（２）構成部品の加工法の自由度が増し、従来の機械加
工廃止が可能であると共に、それぞれの構成部品に適合
する加工法を選択でき、コスト低減が図れる。
（３）軸の長短が自由に選択でき軸長の異なる仕様のエ
ンジンにも適用できる。
【０００５】
【発明が解決しようとする課題】しかしながら、図４で
参照したカム軸の場合、溶接によった場合の機械的強度
を、一体形成の場合もしくはキー等による回り止め手段
を用いた場合の機械的強度と比較すると、溶接した場合
の機械的強度は耐久性も含めて低く、且つ向上させるこ
とも難しいので歯車２０１による伝達トルクには限界が
ある。その対策として、例えば、軸２０２の歯車２０１
の結合部の径を大きくすることが考えられるが、軸２０
２が段付きになってカム軸２０７の生産コストが高くな
ると云う欠点があった。
【０００６】本発明の目的は、生産コストの上昇を招く
ことなく、伝動用歯車の伝達トルクの増大が可能となる
内燃機関のカム軸を提供するにある。
【０００７】
【課題を解決するための手段】本発明に係る内燃機関の
カム軸製造方法は、伝動用の歯車（１）を一体で形成し
た冷間鍛造の駆動軸（２）に吸排気弁開閉用のカム
（３）を組付ける内燃機関のカム軸製造方法において、
前記駆動軸のカム挿入部の断面形状をカムの挿入孔
（４）に圧入可能な略四角形状に形成し、該略四角形状
の角部（５）を塑性変形させながら前記駆動軸を前記カ
ムに圧入することを特徴とする。
【０００８】
【作用】前記のように構成された内燃機関のカム軸の場
合、軸滑りトルクの条件が最も厳しい伝動用の歯車１を
駆動軸２とともに冷間鍛造で一体成形とした場合、歯車
１の伝達トルクを大幅に増大させることができる。かか
る発明によれば、駆動軸２のカム挿入部の断面形状をカ
ムの挿入孔４に圧入可能な略四角形状に形成し、該略四
角形状の角部５を塑性変形させながら前記駆動軸を前記
カムに圧入するという機械的固定手段によるので、冷間
鍛造の駆動軸２の素材硬度は比較的低いのに対して、カ
ム３の素材硬度は摩耗防止の上から比較的高い。従って
駆動軸２にカム３を圧入する際に、冷間鍛造時に形成し
た駆動軸２の断面がほぼ四角形状の角部５をカム３の挿
入孔によって容易に塑性変形させながら圧入させること
ができる。
【０００９】
【実施例】次に、本発明の実施例の構成を図１〜図２に
よって説明する。図１は実施例に係るカム軸７の構成図
で、伝動用の歯車１が一体に形成されている冷間鍛造の
駆動軸２に、吸排気弁を開閉するカム３が次に述べる機
械的固定手段により軸方向の位置決め後、回転不能に取
付けられている。図２は機械的固定手段の場合の説明図
で、冷間鍛造の駆動軸２のカム３の挿入部の断面形状
と、カム３の駆動軸２への挿入孔４の断面形状とを、駆
動軸２を塑性変形させた状態での圧入可能な形状、この
場合は駆動軸２の断面をほぼ四角形状とし、その角部５
を塑性変形させながらカム３を駆動軸２に圧入させてい
る。
【００１０】次に、本実施例の作用について説明する。
前記のように構成された内燃機関のカム軸７の場合、軸
滑りトルクの条件が最も厳しい歯車１を駆動軸２ととも
に冷間鍛造で一体成形しているため、歯車１の伝達トル
クを大幅に増大させることができる。また、かかる機械
的固定手段による場合、冷間鍛造の駆動軸２の素材硬度
は比較邸低いのに対して、焼結等により成形したカム３
の硬度は摩耗防止の上から比較的高い。従ってカム３を
駆動軸２に圧入する際に、冷間鍛造時に形成した駆動軸
２の断面がほぼ四角形状の角部５をカム３の挿入孔４に
よって容易に塑性変形させながら圧入することができ
る。
【００１１】
【発明の効果】本発明によれば、歯車とカムを駆動軸に
溶接することなく、生産コストの上昇を招かずに、歯車
の伝達トルクの大幅な増大が可能となる内燃機関のカム
軸を得ることができる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a camshaft of an internal combustion engine. 2. Description of the Related Art FIG. 3 shows a front view of a first conventional camshaft. A transmission gear or sprocket (hereinafter abbreviated as a gear) for interlocking with the crankshaft and a camshaft formed by coaxially fixing a cam for opening and closing the intake and exhaust valves are formed by forging or casting. The journal 104, the cam 103, the gear 101, etc. are machined as shown in FIG.
7 was integrally formed, or only the gear was machined from a material different from the shaft portion 102, and was fixed to the shaft portion 102 with a key or the like. However, such conventional means has the following problems. (1) As the material of the camshaft 107, a high-grade material that meets the wear resistance requirements of the cam portion 103 and the gear portion 101 is required. (2) Journal 104, cam 103, gear 10
A large amount of expense is required for processing equipment and processing man-hours in order to commercialize 1 etc. by machining. Next, as a second conventional example, FIG. 4 shows a longitudinal sectional view of a camshaft (invented in Japanese Utility Model Laid-Open No. 02-157637) which solves the above-mentioned problem. As shown in the figure, the cam shaft 207 includes the shaft 202, the cam 203, and the gear 20.
1. It is composed of a thrust washer 205. The axis 202 is
It is used as a journal portion of the cam shaft 207, and a bar-shaped steel bar which has been subjected to centerless grinding is used. A tube may be used as a substitute for the drawn bar. Cam 2
In 03, a sintered material may be used instead of a machined product. As the gear 201, a machined product is used, but a sheet metal molded product, a resin, or the like can also be used. As the thrust washer 205 used to determine the side dimensions of the shaft 202, a sheet metal molded product is used. The cam shaft 207 is formed by press-fitting the cam 203, the gear 201, and the thrust washer 205 into the shaft 202. However, instead of press-fitting, the cam shaft 207 may be integrated by laser welding or brazing. [0004] The cam shaft 207 shown in FIG. 4 has the following effects by forming all the constituent parts as separate bodies and integrally connecting them in a subsequent step. (1) Materials suitable for each component can be selected,
Material costs can be reduced. (2) The degree of freedom in the processing method of the component parts is increased, the conventional machining can be abolished, and a processing method suitable for each component part can be selected, so that the cost can be reduced. (3) The length of the shaft can be freely selected, and the present invention can be applied to engines having different shaft lengths. [0005] However, in the case of the camshaft referred to in FIG. 4 , the mechanical strength in the case of welding is reduced in the case of integral formation or in the case of using a detent means such as a key. As compared with the mechanical strength of the gear 201, the mechanical strength at the time of welding is low including durability, and it is difficult to improve the mechanical strength. As a countermeasure, for example, the gear 201 of the shaft 202
It is conceivable to increase the diameter of the joint of the shaft 20.
2 has a disadvantage that the production cost of the camshaft 207 increases due to the step. An object of the present invention is to provide a camshaft of an internal combustion engine that can increase the transmission torque of a transmission gear without increasing production costs. A method of manufacturing a camshaft for an internal combustion engine according to the present invention comprises integrally forming a transmission gear (1).
Cold forging drive shaft (2) with intake / exhaust valve opening / closing cam
In the method for manufacturing a camshaft of an internal combustion engine to which (3) is assembled,
The cross section of the cam insertion part of the drive shaft is inserted into the cam insertion hole.
(4) formed into a substantially square shape that can be press-fitted into the substantially square shape;
While the corner (5) of the drive shaft is plastically deformed, the drive shaft is
It is characterized by being press-fitted into the system. In the case of the camshaft of the internal combustion engine configured as described above, the transmission gear 1 having the strictest condition of the shaft slip torque is integrally formed together with the drive shaft 2 by cold forging. In this case, the transmission torque of the gear 1 can be greatly increased. Heel
According to the invention, the cross-sectional shape of the cam insertion portion of the drive shaft 2 is
Into a substantially square shape that can be pressed into the insertion hole 4 of the
While plastically deforming the angular corner 5, the drive shaft is
Since by mechanical fixing means of press-fitting the cams, material hardness of the drive shaft 2 of the cold forging whereas relatively low, the material hardness of the cam 3 is relatively high from the top of the anti-wear. Therefore, when the cam 3 is press-fitted into the drive shaft 2, the corner 5 having a substantially square cross section of the drive shaft 2 formed at the time of cold forging can be press-fitted while being easily plastically deformed by the insertion hole of the cam 3. . [0009] [Embodiment] Next, a configuration of an embodiment of the present invention by Figures 1-2. Figure 1 is a configuration diagram of a cam shaft 7 according to the embodiment, the drive shaft 2 of the cold forging of the gear 1 for transmission is integrally formed, the machine described cam 3 for opening and closing the intake and exhaust valves then < It is non-rotatably mounted after axial positioning by mechanical fixing means. Figure 2 is an explanatory diagram in the case of the machine械的fixing means, the cross-sectional shape of the insertion portion of the cam 3 of the drive shaft 2 of the cold forging, and a cross-sectional shape of the insertion hole 4 to the driving shaft 2 of the cam 3, The shape which can be press-fitted in a state in which the drive shaft 2 is plastically deformed, in this case, the cross section of the drive shaft 2 is substantially square, and the corner 5
The cam 3 is pressed into the drive shaft 2 while plastically deforming
You. Next, the operation of this embodiment will be described.
If the camshaft 7 of the internal combustion engine formed as before reporting, since the condition of the shaft slip torque is integrally molded by cold forging the strictest gear 1 with the drive shaft 2, significant transmission torque of the gear 1 Can be increased. In the case of using such mechanical fixing means, the material hardness of the drive shaft 2 for cold forging is comparatively low, while the cam 3 formed by sintering or the like is used.
Has a relatively high hardness for preventing abrasion. Therefore, when the cam 3 is press-fitted into the drive shaft 2, it is possible to press-fit the corner portion 5 of the drive shaft 2 formed at the time of cold forging, which has a substantially square cross section, by easily plastically deforming the same through the insertion hole 4 of the cam 3. Can
You. According to the present invention, the transmission torque of the gear can be greatly increased without welding the gear and the cam to the drive shaft and without increasing the production cost. A camshaft can be obtained.
【図面の簡単な説明】
【図１】 本発明の実施例に係るカム軸の縦断面図
【図２】 図１におけるII−II矢視横断面図で、本発明
に係る機械的固定手段の説明図
【図３】 第１従来例のカム軸の正面図
【図４】 第２従来例のカム軸の縦断面図
【符号の説明】
１…歯車、２…駆動軸、３…カム、４…挿入孔、５…角
部。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of a cam shaft according to an embodiment of the present invention . FIG. 2 is a transverse sectional view taken along the line II-II in FIG. FIG. 3 is a front view of a cam shaft according to a first conventional example. FIG . 4 is a vertical sectional view of a cam shaft according to a second conventional example. ... insertion holes, 5 ... corners.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) F01L 1/04 F16H 53/02 ──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. 7 , DB name) F01L 1/04 F16H 53/02
Claims (1)
間鍛造の駆動軸（２）に吸排気弁開閉用のカム（３）を
組付ける内燃機関のカム軸製造方法において、前記駆動
軸のカム挿入部の断面形状をカムの挿入孔（４）に圧入
可能な略四角形状に形成し、該略四角形状の角部（５）
を塑性変形させながら前記駆動軸を前記カムに圧入する
ことを特徴とする内燃機関のカム軸製造方法。 (57) [Claims 1] A cooling device in which a transmission gear (1) is integrally formed.
A cam (3) for opening and closing the intake and exhaust valves on the drive shaft (2)
In the method for manufacturing a camshaft of an internal combustion engine to be assembled, the driving method
Pressing the cross-sectional shape of the cam insertion part of the shaft into the cam insertion hole (4)
Formed in a possible substantially square shape, and the corner portion of the substantially square shape (5)
Press-fit the drive shaft into the cam while plastically deforming
A method for manufacturing a camshaft of an internal combustion engine, comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19510393A JP3396261B2 (en) | 1993-07-12 | 1993-07-12 | Method of manufacturing camshaft for internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19510393A JP3396261B2 (en) | 1993-07-12 | 1993-07-12 | Method of manufacturing camshaft for internal combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0726910A JPH0726910A (en) | 1995-01-27 |
| JP3396261B2 true JP3396261B2 (en) | 2003-04-14 |
Family
ID=16335575
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19510393A Expired - Fee Related JP3396261B2 (en) | 1993-07-12 | 1993-07-12 | Method of manufacturing camshaft for internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3396261B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005056986A1 (en) * | 2003-12-12 | 2005-06-23 | Honda Motor Co., Ltd. | Camshaft, method of manufacturing cam for camshaft, and method of manufacturing shaft for camshaft |
| JP4610887B2 (en) * | 2003-12-12 | 2011-01-12 | 本田技研工業株式会社 | Manufacturing method of shaft for camshaft |
| JP2006169960A (en) * | 2003-12-12 | 2006-06-29 | Honda Motor Co Ltd | Camshaft |
| JP4671923B2 (en) * | 2006-06-30 | 2011-04-20 | 本田技研工業株式会社 | Internal combustion engine camshaft structure |
-
1993
- 1993-07-12 JP JP19510393A patent/JP3396261B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0726910A (en) | 1995-01-27 |
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