JP2009050859A - Method of manufacturing two parts, for example, inner parts and outer parts - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing two parts, for example, an inner parts and an outer parts so that material loss is reduced and cracks are not generated on the sheared plane. <P>SOLUTION: The outer parts and the inner parts which is provided inside the outer parts are manufactured from one starting material by shearing work. First, the start material is sheared into an uncompleted shape to the midway with a punch and a die. At that time, the cracks are not generated on the sheared plane. Shearing work is performed by dividing at least into two stages. First, by the first shearing, the material is made into a half-punched state where the outer periphery of the semi-finished part of the inner parts is partially connected to the inner periphery of the semi-finished part of the outer parts. Before performing the next shearing work, softening treatment is applied to the semi-finished part of the inner parts and the semi-finished part of the outer parts which are in the half-punched state. The semi-finished part of the inner parts and the semi-finished part of the outer parts to which the softening treatment is applied are sheared wholly without generating the cracks on the seared plane. In the above manner, the inner parts and the outer parts are punched down. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing two parts, for example an outer part and an inner part provided on the inside, from one starting material by shearing.

  A trochoid pump is known as an oil pump that generates hydraulic pressure. See US Pat.

  Trochoid pumps are used in various engines including automobile engines. The main parts of the trochoid pump are an inner rotor and an outer rotor.

  A general manufacturing method of the inner rotor and the outer rotor is as follows.

(A) A method of sintering and molding a powder material.

(B) A method of cutting a long drawn material having a tooth-shaped cross section at a fixed size and finishing the end face, inner face, and outer face.

(C) A method of producing a rough shape by hot forging or cold forging and finishing by cutting.

(D) A method of cutting the entire surface of a solid bar.

(E) A method in which a cutting allowance is added to the tooth mold portion and shear roughing is performed, and the tooth profile is finished by cutting.
Japanese Patent Laid-Open No. 11-22656

  Each of the manufacturing methods (a) to (e) described above has the following drawbacks.

(A) Powder materials have been expensive for some time, but have recently increased. On the physical side, the powder material tends to have a non-uniform internal density. Therefore, the powder material is fragile and tends to cause partial defects.

(B) The long material has a large manufacturing facility and a large capital investment. Without mass production, it will be expensive. The large number of manufacturing processes is also a cost factor. Furthermore, since the long material becomes heavy, it is easy to damage the surface during handling. The wound on the tooth mold surface becomes a serious defect. Moreover, although fixed-size cutting is performed by saw cutting or grinding wheel cutting, both have a large material loss. Long cutting time.

(C) In the case of cutting, the processing time is long. The processing equipment must have high accuracy and high functionality. Suitable for small volume production.

(D) The material yield is poor. Processing time is enormous. The processing equipment must have high precision and high functionality. It can be said that it is suitable for trial manufacture.

(E) The reason why the tooth mold portion is sheared with a cutting allowance is to avoid the occurrence of cracks in the middle of the shear surface. The crack becomes a starting point of the burning crack at the time of the curing heat treatment. Further, the flatness and the surface roughness cannot satisfy the design requirements (unless the surface layer is removed by cutting).

  In recent years, the price of steel materials has risen, and it is trying to improve the yield of material usage and suppress the cost increase.

  An object of the present invention is to provide a method for manufacturing two parts, for example, an inner part and an outer part, in which loss of material is reduced and a crack is not generated on a shearing surface.

  Examples of the solving means of the present invention are as follows.

(1) A method in which an outer part and an inner part provided inside the outer part are manufactured from one starting material by shearing,
The starting material is sheared halfway by a punch and die so that no cracks occur in the shearing surface, and the outer periphery of the inner part half-processed part is partially connected to the inner periphery of the outer part semi-processed part. A process to become a state;
A process of softening at least a connection part of a half-worked part of the inner part and a half-worked part of the outer part in a half-drawn state;
The step of removing the inner part and the outer part by further shearing so that the half-processed part of the inner part and the half-processed part of the outer part subjected to the softening treatment are not sheared, and
A method for producing an inner part and an outer part, comprising:

(2) The method for manufacturing the inner part and the outer part described above, wherein the inner part and the outer part are an inner rotor and an outer rotor of a trochoid pump, respectively.

(3) After the softening treatment, the lubrication target film disposed on a surface of the semi-processed portion surface and the outer part of the blank portion of the inner part, after that, the semi-processed portion of the semi-processed portion and the outer part of the inner part The method for producing an inner part and an outer part as described above, wherein the inner part and the outer part are removed by being sheared so as not to cause a crack on the shearing surface.

(4) The method for manufacturing the inner part and the outer part described above, wherein a single sheet is used as a starting material.

(5) A method in which a first part and a second part sized to fit inside the first part are manufactured from one starting material by shearing,
The starting material is sheared halfway by a punch and die so that no cracks occur in the shearing surface, and the outer periphery of the half-worked part of the second part is partially connected to the inner circumference of the half-worked part of the first part. A process of becoming half-extracted,
A step of at least partially softening the half-worked part of the first part and the half-worked part of the second part in a half-punched state;
The step of removing the first part and the second part by further shearing the half-processed part of the first part and the half-processed part of the second part that have been subjected to the softening treatment so as not to cause cracks in the shearing surface. When,
A method for manufacturing two parts, comprising:

  (1) Parts can be manufactured without waste by effectively using the material portion that was previously scrapped. Therefore, material loss is significantly reduced. Great resource saving effect. For example, only one material was required. Moreover, one material preparation step is not required.

  (2) When an inner part and an outer part are made from a single plate material, material loss is extremely small.

  (3) When manufacturing a disk-shaped or ring-shaped gear sprocket using a plate material as a starting material, the processing load can be significantly reduced as compared with a general cold forging method. Moreover, it is not necessary to cut the tooth mold part.

  According to a preferred embodiment of the invention, the outer part and the inner part provided inside the outer part are manufactured from one starting material by shearing. The starting material is sheared halfway by a punch and die into an incomplete shape. At that time, no crack occurs on the shearing surface. Shearing is performed in at least two stages. First, in the first shearing process, the outer periphery of the half-processed part of the inner part is in a half-drawn state in which it is partially connected to the inner periphery of the semi-processed part of the outer part via a connecting part. Before the next shearing process, at least the connection part and the vicinity thereof are softened in the half-worked part of the inner part and the half-worked part of the outer part in the half-drawn state. About the half process part of the inner part which carried out the softening process, and the half process part of an outer part, a shear process is carried out as a whole, without a crack being produced in a shear plane. In this way, the inner part and the outer part are removed.

  According to another embodiment of the invention, two parts are produced from one starting material by at least two shearing operations. For example, in the first shearing process, before the crack occurs on the sheared surface during the process, the process is stopped and a semi-processed product is produced. Next, the semi-processed product is softened by heat treatment or the like. Thereafter, a second shearing process is performed. As a result, it is possible to reliably avoid the generation of cracks in the shearing surface and perform all the shearing processes.

  When the starting material is pulled out of the inner part and the outer part by a single shearing process as in the prior art, cracks tend to occur on the shearing surface of the workpiece. There are parts that can be used even if cracks occur on the shearing surface, but if any cracks occur on the shearing surface, they cannot be used as parts such as the inner rotor and outer rotor of the trochoid pump.

  It is inefficient to inspect all products for cracks on the shear surface, especially in mass production.

  In the present invention, the shearing operation is temporarily stopped shortly before the crack starts to occur. Then, after a softening treatment (annealing, etc.), the shearing process is performed again. As such, the shearing process is completed, and the inner part and the outer part are removed to separate them.

  According to the knowledge of the present inventor, the position where cracks start to occur varies depending on the conditions described below.

(1) Grade (2) Metal structure (3) Material hardness (4) Roundness of punch tip corner and roundness of lower mold corner (5) Dimensions of punch diameter and lower mold hole diameter Difference (gap size)
(6) Processing speed In consideration of such various conditions, it is preferable to obtain the position at which a crack starts to occur by conducting experiments, observations, actual measurements, etc. in advance before actual mass production. An example of a simple method is to measure the distance from the entrance (starting edge) of the shear surface to the crack by performing the extraction of the inner part and the outer part with a single shearing process of the starting material as in the past. . With reference to the measured distance, the position where the punch is stopped at the time of the first shearing process is determined in advance, and at the time of actual mass production, the first shearing process is always performed at the predetermined position. When to stop punching.

  According to the research of the present inventor, the position where the punch is stopped in the first shearing process is 5 to 15% (processing rate) before the position where the crack starts to occur, that is, 95 to 85% from the entrance (starting edge) of the shear surface. It is best to set this position.

  Preferably, during the first shearing process, the movement of the punch is stopped at such a predetermined position, and the half-processed product is placed in the lower mold in the middle of the shearing process, that is, in the half-drawn state. Remove with a knockout pin. Thereafter, the semi-processed product is softened (for example, annealed) to reduce the internal hardness of the semi-processed product. Next, a film treatment for preventing seizure is performed. Thereafter, the shearing process is completed by the second shearing process, the inner part and the outer part are pulled out, and both are separated.

  If it does in this way, it can avoid reliably that a crack generate | occur | produces in the shearing surface of both inner parts and outer parts.

  For example, when an inner rotor and an outer rotor are manufactured by cold forging, both parts can be taken together from a single starting material. As a result, material loss is greatly improved.

  According to another embodiment of the present invention, in the first step, the inner rotor is formed in a half-punched state by punching. In the next (rear) step, the tooth profile of the outer rotor is formed in a half-drawn state.

  As in the case of processing the inner rotor, a tooth profile can be formed on the outer periphery of the sprocket. The sprocket is preferably finished by a protruding method or a sizing method in the next process (post process) to ensure accuracy without cutting the tooth mold part. Such a construction method is suitable for a part having a relatively large diameter and a small (thin) tooth thickness.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  As an example of a manufacturing method of an outer part and an inner part provided inside the outer part, a method of manufacturing an outer rotor and an inner rotor of an oil pump from one starting material by two shearing processes will be described.

  In FIG. 1, the starting material 10 is a single disk-shaped metal material.

  As shown in FIG. 2, starting material 10 is sheared halfway by punch 11 and die 12.

  In FIG. 2, the starting material 10 is placed at a predetermined position on the upper surface of the die 12, the punch 11 is lowered from above, and the center portion and the peripheral portion of the starting material 10 are sheared halfway. At this time, the shearing surface is not cracked.

  According to the knowledge of the present inventor, cracks tend to occur particularly at the corners indicated by X and Y in FIG. Various conditions such as grade, metal structure, material hardness, punch tip corner roundness and lower mold corner roundness, punch diameter and lower mold hole diameter dimensions (gap size), processing speed, etc. In consideration of the above, the position where the crack starts to occur (difference T between the processing end surface of the punch 11 and the processing end surface of the die 12) is obtained by conducting experiments, observations, actual measurements, etc. in advance before the actual processing operation. Keep it.

  For example, the position at which the punch 11 is stopped by the first shearing process is set to a position 5 to 15% before the crack starting position (predetermined position) (at a position 85 to 95% from the start end of the shear plane). It is best to do.

  In the first shearing process, the downward movement of the punch 11 is stopped, and the half-processed products 10a and 10b are pushed up from the lower die 12 by the knockout pin 13 in the middle of the shearing process, that is, in the half-drawn state. Take out.

  As shown in FIG. 3, the upper part of the outer periphery of the semi-processed part 10b of the inner part is in a half-drawn state where it is partially connected to the lower part of the inner periphery of the semi-processed part 10a of the outer part at the connection part 10c. At this time, cracks are not generated in the shear surfaces 10d and 10e.

  The semi-processed part 10b of the inner part and the semi-processed part 10a of the outer part in the half-drawn state are softened (for example, annealed).

  In the illustrated example, the entire half-processed portions 10a and 10b are softened. However, if necessary, at least only the connecting portion 10c and the vicinity thereof may be softened (for example, annealed). Good. Moreover, you may soften the shear surface and the connection part 10c of the semi-processed part 10b of an inner part, and the semi-processed part 10a of an outer part.

  As shown in FIG. 4, the softened inner part half-processed part 10b and outer part half-processed part 10a are subjected to the second shearing process so that the shearing surfaces 10d and 10e do not crack. Done. That is, the inner part 10B and the outer part 10A are removed.

  In the second shearing process shown in FIG. 4, the punch 11, the die 12, and the knockout pin 13 shown in FIG. 2 may be used, or another punch, die, knockout pin, and the like may be used. .

  In the illustrated example, the outer diameter d1 (FIG. 2) of the cylindrical processed portion of the punch 11 is equal to the inner diameter d2 (FIG. 4) of the outer part 10A.

  In the illustrated example, the inner part 10B and the outer part 10A are an inner rotor and an outer rotor of a trochoid pump, respectively.

  Preferably, after the softening process, before removing both parts, a lubricant film is provided on the surfaces of the half-processed part 10b of the inner part and the semi-processed part 10a of the outer part. That is, after applying the lubricating coating, the inner part 10B and the outer part 10A are removed.

  The present invention is not limited to the method of manufacturing the inner part and the outer part disposed outside the inner part.

  For example, the present invention includes a method for manufacturing a ring-shaped or disk-shaped component such as a sprocket. In that case, a ring-shaped part and a disk-shaped part having dimensions that can be inside the ring-shaped part are produced from one starting material by shearing.

  First, the starting material is sheared halfway by a punch and die so that cracks do not occur on the shearing surface, and the outer periphery of the half-processed part of the disk-shaped part is partially connected to the inner periphery of the semi-processed part of the ring-shaped part It will be half-drawn.

  The softening process is performed on the half-processed part of the disk-shaped part and the half-processed part of the ring-shaped part in the half-cut state.

  Further, the half-processed part of the softened disc-shaped part and the half-processed part of the ring-shaped part are further sheared so as not to cause a crack on the shearing surface. Thereby, the disk-shaped part and the ring-shaped part are removed.

  As preferable examples of the disk-shaped part and the ring-shaped part, there can be mentioned a disk-shaped gear and a ring-shaped gear, respectively.

  Furthermore, the present invention includes a method of manufacturing a completely different type of component, for example, a method of manufacturing a sprocket and a completely different type of component.

  In any form, usually, after cutting off two parts and separating the two parts, the desired processing is performed in the next (post) process.

Schematic explanatory drawing which shows an example of the starting material used for this invention method. Schematic explanatory drawing which shows an example of the half extraction process of this invention method. The schematic explanatory drawing which shows an example of the half process part of the inner part in the half-punched state processed by the method of this invention, and the half process part of an outer part. Schematic explanatory drawing which shows an example of the extraction process of this invention method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Starting material 10A Outer part 10a Half process part of outer part 10B Inner part 10b Half process part of inner part 11 Punch 12 Die 13 Knockout pin

Claims (5)

An outer part and an inner part provided inside the outer part are manufactured from one starting material by shearing,
The starting material is sheared halfway by a punch and die so that no cracks occur in the shearing surface, and the outer periphery of the inner part half-processed part is partially connected to the inner periphery of the outer part semi-processed part. A process to become a state,
A process of softening at least a connection part of a half-worked part of the inner part and a half-worked part of the outer part in a half-drawn state;
The step of removing the inner part and the outer part by further shearing so that the half-processed part of the inner part and the half-processed part of the outer part subjected to the softening treatment are not sheared, and
A method for producing an inner part and an outer part, comprising:   The method for manufacturing an inner part and an outer part according to claim 1, wherein the inner part and the outer part are an inner rotor and an outer rotor of a trochoid pump, respectively.   After the softening treatment, a lubricating film is provided on the surface of the half-processed part of the inner part and the surface of the semi-processed part of the outer part, and then the half-processed part of the inner part and the half-processed part of the outer part are placed on the shearing surface. 3. The method of manufacturing an inner part and an outer part according to claim 1 or 2, wherein the inner part and the outer part are removed by shearing so as not to cause a crack.   The method for producing an inner part and an outer part according to any one of claims 1 to 3, wherein one plate material is used as a starting material. A method in which a first part and a second part sized to fit inside the first part are manufactured from one starting material by shearing,
The starting material is sheared halfway by a punch and die so that no cracks occur in the shearing surface, and the outer periphery of the half-worked part of the second part is partially connected to the inner circumference of the half-worked part of the first part. A process of becoming half-extracted,
A step of at least partially softening the half-worked part of the first part and the half-worked part of the second part in a half-punched state;
The step of removing the first part and the second part by further shearing the half-processed part of the first part and the half-processed part of the second part that have been subjected to the softening treatment so as not to cause cracks in the shearing surface. When,
A method for manufacturing two parts, comprising:

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