EP0750955A1 - Method of molding a poppet valve having a smaller diameter portion - Google Patents
Method of molding a poppet valve having a smaller diameter portion Download PDFInfo
- Publication number
- EP0750955A1 EP0750955A1 EP95110190A EP95110190A EP0750955A1 EP 0750955 A1 EP0750955 A1 EP 0750955A1 EP 95110190 A EP95110190 A EP 95110190A EP 95110190 A EP95110190 A EP 95110190A EP 0750955 A1 EP0750955 A1 EP 0750955A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- smaller diameter
- diameter portion
- cavity
- valve
- poppet valve
- 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.)
- Withdrawn
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21K—MAKING FORGED OR PRESSED METAL PRODUCTS, e.g. HORSE-SHOES, RIVETS, BOLTS OR WHEELS
- B21K1/00—Making machine elements
- B21K1/20—Making machine elements valve parts
- B21K1/22—Making machine elements valve parts poppet valves, e.g. for internal-combustion engines
Definitions
- the present invention relates to a method of molding a poppet valve by hot forging, and particulaly, to a method of molding a poppet valve having smaller diameter portion at the end of a valve stem, the poppet valve being used in an internal combustion engine for an automobile.
- FIG. 2 (A) shows cylindrical steel material 101 (slag), which is heated to a certain temperature and filled into a drag 102 in a primary step as shown in Fig. 2 (B).
- the drag 102 in the primary step has a cavity which corresponds to a larger diameter valve head 104 and a smaller diameter valve stem 105.
- the heated material 101 is forged under compression by a punch 106 (cope) to make an intermediate molded material 103, which is then filled into a drag 107 in a secondary step as shown in Fig. 2(C).
- a smaller diameter portion 114 may be formed in a poppet valve 111.
- the smaller diameter portion 114 has a cotter groove 115 in which a pair of cotters (not shown) are engaged.
- valve head 112 and the valve stem 113 are formed by the step in Fig. 2(C), and then it is worked by mechanical means such as by a centerless grinder, thereby increasing time for the mechanical processing and reducing productivity to increase cost for manufacturing. It may arise a problem that the life of the grinding wheels becomes shorter and replacement thereof is often made.
- an object of the present invention to provide a method of molding a poppet valve to form a smaller diameter portion at the end of a valve stem at the same time.
- a method of molding a poppet valve having a smaller diameter portion comprising the steps of filling heated material into a drag having a cavity for forming a valve head, a cavity for forming a valve stem and a cavity for forming the smaller diameter portion, the cavities communicating with one another; and compressing an upper end of the material in the cavities by a punch to conduct hot forging to form the poppet valve.
- the smaller diameter portion is not mechanically formed, but is formed by hot forging process, thereby decreasing the number of mechanical steps after forging, and increasing productivity and duration of tools.
- the portion ground in a grinding process may be reduced to save the amount of material, thereby decreasing cost for manufacturing.
- the smaller diameter portion is hardened by forging, and the strength thereof, especially tensile strength, is significantly increased compared with a product mechanically worked.
- FIG. 1 illustrates a device which is applied to the primary step.
- a drag for the primary step comprises an upper die 1 and an upper die insert 2 under the upper die 1.
- the upper die 1 has a cavity 3 which corresponds to a larger diameter valve head 7 in the intermediate product, and a cavity 4 for forming a valve stem 8.
- the upper die insert 2 has a cavity 5 which is smaller than the cavity 4 in diameter.
- the cavity 5 for forming the smaller diameter portion communicates with the cavity 4 of the upper die 1 via a curved circumferential edge 10, so that the smaller diameter portion 9 is smoothly connected with the valve stem 3.
- Heated material (not shown) is supplied into the cavity 3 through an upper opening of the upper die 1, and is forged under compression by the punch 6, so that the material flows downwards while it is elastically deformed, thereby forming the valve head 7 and the valve stem 8.
- the pressurized deformation is continued, and the end of the valve stem 8 flows into the cavity 5 of the upper die insert 2 to form the smaller diameter portion 9.
- the smaller diameter portion 9 is connected with the valve stem 8 via a concave surface by the upper circumferential edge 10 of the cavity 5, thereby forming the intermediate molded product comprising the valve head 7, the valve stem 8 and the portion 9 having diameter smaller than the valve stem 8.
- a desired poppet valve is formed in the secondary step, and a groove for a cotter is mechanically formed at a desired position of the smaller diameter portion, thereby manufacturing a final poppet valve as shown in Fig. 3.
- the smaller diameter portion 9 is formed in the primary step, but may be formed in the secondary step.
- the upper die insert 2 may be integrally formed with the drag 1.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- Forging (AREA)
Abstract
Heated material (101) is filled into a cavity (3) which has three portions having different diameter. By compressing the material in the cavity (3) by a punch (6), there is formed a poppet valve which comprises a valve head (7), a valve stem (8) and a smaller diameter portion (9) which is provided at the end of the valve stem (8).
Description
- The present invention relates to a method of molding a poppet valve by hot forging, and particulaly, to a method of molding a poppet valve having smaller diameter portion at the end of a valve stem, the poppet valve being used in an internal combustion engine for an automobile.
- A poppet valve is conventionally molded by hot forging as shown in Fig. 2 (A) to (C). Fig. 2 (A) shows cylindrical steel material 101 (slag), which is heated to a certain temperature and filled into a
drag 102 in a primary step as shown in Fig. 2 (B). Thedrag 102 in the primary step has a cavity which corresponds to a largerdiameter valve head 104 and a smallerdiameter valve stem 105. The heatedmaterial 101 is forged under compression by a punch 106 (cope) to make an intermediate moldedmaterial 103, which is then filled into adrag 107 in a secondary step as shown in Fig. 2(C). In thedrag 107 of the secondary step, there is a cavity which corresponds to avalve head 109 and thevalve stem 105 of apoppet valve 108 finally molded. Thevalve head 104 of the intermediate moldedmaterial 103 is compressed by apunch 110 to mold thevalve head 109 to make thepoppet valve 108. - As shown in Fig. 3, a smaller diameter portion 114 may be formed in a
poppet valve 111. In order to mount the poppet valve in an engine, the smaller diameter portion 114 has acotter groove 115 in which a pair of cotters (not shown) are engaged. - To form the smaller diameter portion 114 at the end of the
valve stem 113 of thepoppet valve 111 as shown in Fig. 3, thevalve head 112 and thevalve stem 113 are formed by the step in Fig. 2(C), and then it is worked by mechanical means such as by a centerless grinder, thereby increasing time for the mechanical processing and reducing productivity to increase cost for manufacturing. It may arise a problem that the life of the grinding wheels becomes shorter and replacement thereof is often made. - To overcome the disadvantage, it is an object of the present invention to provide a method of molding a poppet valve to form a smaller diameter portion at the end of a valve stem at the same time.
- According to the present invention, there is provided a method of molding a poppet valve having a smaller diameter portion, the method comprising the steps of filling heated material into a drag having a cavity for forming a valve head, a cavity for forming a valve stem and a cavity for forming the smaller diameter portion, the cavities communicating with one another; and compressing an upper end of the material in the cavities by a punch to conduct hot forging to form the poppet valve.
- In the method of forming the poppet valve according to the present invention, the smaller diameter portion is not mechanically formed, but is formed by hot forging process, thereby decreasing the number of mechanical steps after forging, and increasing productivity and duration of tools. The portion ground in a grinding process may be reduced to save the amount of material, thereby decreasing cost for manufacturing. The smaller diameter portion is hardened by forging, and the strength thereof, especially tensile strength, is significantly increased compared with a product mechanically worked.
- The features and advantages of the present invention will become more apparent based on the following description with respect to accompanying drawings:
- Fig. 1 is a sectional view of a hot forging device by which the present invention is carried out;
- Fig. 2 is a schematic view which illustrates the conventional steps of forming a poppet valve, (A) showing material, (B) being a primary step, (C) being a secondary step; and
- Fig. 3 is a perspective view of a poppet valve having a smaller diameter portion at the end.
- There are two hot forging steps which comprises a primary step for forming an intermediate product from original material and a secondary step for molding a poppet valve from the intermediate product. Fig. 1 illustrates a device which is applied to the primary step. A drag for the primary step comprises an
upper die 1 and an upper die insert 2 under theupper die 1. Theupper die 1 has acavity 3 which corresponds to a larger diameter valve head 7 in the intermediate product, and acavity 4 for forming a valve stem 8. The upper die insert 2 has acavity 5 which is smaller than thecavity 4 in diameter. - The
cavity 5 for forming the smaller diameter portion communicates with thecavity 4 of theupper die 1 via a curvedcircumferential edge 10, so that the smaller diameter portion 9 is smoothly connected with thevalve stem 3. - Heated material (not shown) is supplied into the
cavity 3 through an upper opening of theupper die 1, and is forged under compression by thepunch 6, so that the material flows downwards while it is elastically deformed, thereby forming the valve head 7 and the valve stem 8. The pressurized deformation is continued, and the end of the valve stem 8 flows into thecavity 5 of the upper die insert 2 to form the smaller diameter portion 9. The smaller diameter portion 9 is connected with the valve stem 8 via a concave surface by the uppercircumferential edge 10 of thecavity 5, thereby forming the intermediate molded product comprising the valve head 7, the valve stem 8 and the portion 9 having diameter smaller than the valve stem 8. - Then, a desired poppet valve is formed in the secondary step, and a groove for a cotter is mechanically formed at a desired position of the smaller diameter portion, thereby manufacturing a final poppet valve as shown in Fig. 3.
- In the embodiment, the smaller diameter portion 9 is formed in the primary step, but may be formed in the secondary step. The upper die insert 2 may be integrally formed with the
drag 1. - The foregoings merely relate to an embodiment of the present invention. Various changes and modifications may be made by person skilled in the art without departing from the scope of claim therein:
Claims (2)
- A method of molding a poppet valve having a smaller diameter portion, the method comprising the steps of:filling heated material into a drag having a cavity for forming a valve head, a cavity for forming a valve stem and a cavity for forming the smaller diameter portion, the cavities communicating with one another; andcompressing an upper end of the material in the cavities by a punch to conduct hot forging to form the poppet valve.
- A method as defined in claim 1 wherein the cavities for forming the valve head and stem are provided in an upper die of the drag, the cavity for forming the smaller diameter portion being provided in an upper die insert under the upper die.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6000329A JPH07208129A (en) | 1994-01-06 | 1994-01-06 | Forming work method for engine valve having shrink diameter part on top end part of stem |
EP95110190A EP0750955A1 (en) | 1994-01-06 | 1995-06-30 | Method of molding a poppet valve having a smaller diameter portion |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6000329A JPH07208129A (en) | 1994-01-06 | 1994-01-06 | Forming work method for engine valve having shrink diameter part on top end part of stem |
EP95110190A EP0750955A1 (en) | 1994-01-06 | 1995-06-30 | Method of molding a poppet valve having a smaller diameter portion |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0750955A1 true EP0750955A1 (en) | 1997-01-02 |
Family
ID=26138699
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP95110190A Withdrawn EP0750955A1 (en) | 1994-01-06 | 1995-06-30 | Method of molding a poppet valve having a smaller diameter portion |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP0750955A1 (en) |
JP (1) | JPH07208129A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104001852A (en) * | 2014-05-13 | 2014-08-27 | 盐城理研精密锻造有限公司 | Besides-star wheel warm piece forging process and upsetting die |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE906777C (en) * | 1951-11-09 | 1954-03-18 | Ruhrtaler Gesenkschmiederei F | Process for hot deforming steel by spraying |
US3587157A (en) * | 1967-11-20 | 1971-06-28 | Weatherhead Co | Method of making a valve stem |
JPS62179846A (en) * | 1986-02-05 | 1987-08-07 | Fuji Valve Kk | Production of engine valve |
JPH02229640A (en) * | 1989-03-02 | 1990-09-12 | Fuji Valve Co Ltd | Forming method for engine valve |
-
1994
- 1994-01-06 JP JP6000329A patent/JPH07208129A/en active Pending
-
1995
- 1995-06-30 EP EP95110190A patent/EP0750955A1/en not_active Withdrawn
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE906777C (en) * | 1951-11-09 | 1954-03-18 | Ruhrtaler Gesenkschmiederei F | Process for hot deforming steel by spraying |
US3587157A (en) * | 1967-11-20 | 1971-06-28 | Weatherhead Co | Method of making a valve stem |
JPS62179846A (en) * | 1986-02-05 | 1987-08-07 | Fuji Valve Kk | Production of engine valve |
JPH02229640A (en) * | 1989-03-02 | 1990-09-12 | Fuji Valve Co Ltd | Forming method for engine valve |
Non-Patent Citations (2)
Title |
---|
PATENT ABSTRACTS OF JAPAN vol. 12, no. 21 (M - 661) 22 January 1988 (1988-01-22) * |
PATENT ABSTRACTS OF JAPAN vol. 14, no. 540 (M - 1053) 29 November 1990 (1990-11-29) * |
Also Published As
Publication number | Publication date |
---|---|
JPH07208129A (en) | 1995-08-08 |
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Legal Events
Date | Code | Title | Description |
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PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
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AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): DE ES FR GB IT |
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17P | Request for examination filed |
Effective date: 19970226 |
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17Q | First examination report despatched |
Effective date: 19981118 |
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STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
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18D | Application deemed to be withdrawn |
Effective date: 19981231 |