JP5194739B2 - Manufacturing method of cylindrical body - Google Patents

Description

  The present invention relates to a method for manufacturing a cylindrical body used in a closed container of a hermetic compressor.

  Conventionally, as a method of expanding a cylindrical body using a die member, a divided die member obtained by dividing the die member into a plurality of parts in the circumferential direction is fitted along the inner peripheral surface of the cylindrical body, and the insertion rod is inserted in this state. Insert into the center of the die member and move each of the divided die members so as to move away from the central axis of the cylinder in the radial direction. (For example, refer to Patent Document 1).

  In addition, as a method of reducing the diameter of the cylindrical body using a die member, a divided die member obtained by dividing the die member into a plurality of parts in the circumferential direction is fitted along the outer peripheral surface of the cylindrical body, and the outer peripheral surface of the die member. In this state, the sliding member is moved in the axial direction so that each of the divided die members is brought closer to the central axis of the cylindrical body in the radial direction. There is one in which the cylindrical body is pressed and contracted in the radial direction by being moved to form a contraction tube (see, for example, Patent Document 2).

  Further, as a method for improving the cylinder accuracy of the cylindrical body in the tube expansion or contraction molding, the die member is constituted by a divided die member divided into a plurality of parts in the circumferential direction, and the divided die member divided into an odd number is used as a cylinder. A method for contracting the body has been proposed (see, for example, Patent Document 3).

FIG. 6 shows the conventional cylindrical tube forming described in Patent Document 3. As shown in FIG. 6, it corresponds to the joining line L of the division | segmentation die members 21-29 by carrying out the reduced tube molding using the division | segmentation die members 21-29 which divided | segmented the die member 2 equally into nine pieces in the circumferential direction. The part Y point corresponding to the center in the circumferential direction of the divided die member is always located at the symmetrical position of the part X point of the cylindrical body A, and as a result, the variation in the diameter of each part of the cylindrical body A is minimized. It can be made small and the cylinder accuracy can be increased.
JP-A-2-84220 JP-A-2-84214 JP 2002-224743 A

  However, in the conventional method of expanding or contracting a cylindrical body, it is possible to suppress variations in the inner diameter or the outer diameter of each part of the cylindrical body in a single expansion or contraction molding. In the case of performing tube expansion or contraction molding multiple times for the purpose of raising, the circumferential contact position of the divided die member with respect to the cylindrical body in the tube expansion or contraction molding is the same, respectively. There was a problem that improvement in cylindrical accuracy could not be expected.

  The present invention solves the above-mentioned conventional problems, and by changing the contact position of the divided die member with respect to the cylindrical body in the circumferential direction for each one of the tube expansion or tube contraction, a plurality of tube expansion or tube contraction is performed. The object is to improve the cylinder accuracy of the cylinder.

  In order to achieve the above object, according to the present invention, a die member that is divided into a plurality of parts in the circumferential direction is fitted on the inner peripheral surface or outer peripheral surface of the cylindrical body, and these divided die members are arranged in the radial direction of the cylindrical body. And expanding or contracting the cylindrical body, the expansion or contraction forming method of the cylindrical body, wherein the expansion or contraction forming is performed a plurality of times. The contact position of the divided die member with respect to the cylindrical body is increased by one time by increasing each time molding or by rotating either the cylindrical body or the die member in the circumferential direction for each expansion or contraction of the tube. The tube is expanded or contracted by changing in the circumferential direction for each expansion or contraction.

  In the pipe expansion or contraction method according to the present invention, the contact position of the divided die member with respect to the cylindrical body is changed in the circumferential direction for each one expansion or contraction molding, so that a plurality of times can be obtained. Cylindrical accuracy of the cylindrical body can be improved by pipe expansion or contraction molding.

  In the first invention of the present application, a die member that is divided into a plurality of portions in the circumferential direction is inserted into the inner peripheral surface or outer peripheral surface of the cylindrical body, and the divided die member is moved in the radial direction of the cylindrical body to form a cylinder. A method of expanding or contracting a cylindrical body that expands or contracts a body, wherein in the expansion or contraction molding in which the expansion or contraction forming is performed a plurality of times, the contact position of the divided die member with respect to the cylindrical body is set once. The tube is expanded or contracted by changing in the circumferential direction every time the tube is expanded or contracted. Thereby, since the contact position of the die member with respect to a certain fixed position of the cylindrical body changes every time the pipe is expanded or contracted, the cylindrical accuracy of the cylindrical body is improved by repeating the molding.

  According to a second aspect of the present invention, a die member that is divided into a plurality of portions in the circumferential direction is inserted into the inner peripheral surface or the outer peripheral surface of the cylindrical body, and the divided die member is moved in the radial direction of the cylindrical body to form a cylindrical body. A method of expanding or contracting a cylindrical body that expands or contracts a tube, and in the expansion or contraction molding in which the expansion or contraction is performed a plurality of times, the number of divisions of the split die member is set for each molding. It has a configuration in which the tube is expanded or contracted by increasing to the same extent as the first invention.

  According to a third aspect of the present invention, a die member that is divided into a plurality of portions in the circumferential direction is fitted on the inner peripheral surface or the outer peripheral surface of the cylindrical body, and the divided die member is moved in the radial direction of the cylindrical body to form a cylindrical body. A method of expanding or contracting a cylindrical body that expands or contracts a tube, wherein the expansion or contraction forming is performed a plurality of times. Each of the expanded or contracted tubes is configured to be rotated in the circumferential direction, and the same effects as those of the first invention can be obtained.

  According to a fourth aspect of the present invention, the number of divisions of the divided die member in the final finish molding is equal to or a multiple of the number of slots of the motor to be assembled and coupled, so that the assembly distortion of the motor when assembled with the motor and the air gap Can prevent problems.

  The fifth invention is the first to fourth inventions in which the cylindrical body is formed by a winding process or a drawing process of a metal flat plate, and the cylindrical precision is low particularly for a cylindrical body immediately after the winding process. Thus, a cylindrical body with high cylindrical accuracy can be provided by performing tube expansion or contraction molding a plurality of times.

  Hereinafter, a method of expanding or contracting a cylindrical body according to an embodiment of the present invention will be described with reference to the drawings. In addition, this invention is not limited by embodiment described below.

(Embodiment 1)
FIGS. 1 to 3 show a method for expanding or contracting a cylindrical body according to Embodiment 1 of the present invention. FIG. 1 is a manufacturing process diagram of a wound tube cylindrical body in the present embodiment, FIG. 2 is a sectional view of primary tube expansion molding in the present embodiment, and FIG. 3 is a sectional view of secondary finish tube expansion molding in the present embodiment. is there.

  As shown in FIG. 1, when creating a wound tube from a metal flat plate, first, primary tube expansion molding is performed on a cylindrical body formed through contraction and welding. After that, secondary finishing tube expansion molding is performed through slag processing and end face cutting processing, and the inner diameter of the cylindrical body is finished within the standard inner diameter dimension. In the present embodiment, the cylindrical body is described as a wound tube, but it goes without saying that the present tube expansion forming method can also be applied to improve the cylindrical accuracy of a cylindrical body even when a drawn tube is formed from a metal flat plate through a drawing process. Yes.

  As shown in FIG. 2, the primary tube expansion molding is performed by dividing the die member 1 equally into eight pieces in the circumferential direction and the cylindrical body formed by winding or drawing from a metal flat plate. A and an insertion rod (not shown). These divided die members 11 to 18 have the same outer peripheral surface as the inner peripheral surface of the cylindrical body A, and the inner peripheral surface is a tapered surface corresponding to an insertion rod (not shown).

  Regarding the operation of the primary tube expansion, the insertion rod is inserted in sliding contact with the inner peripheral surface of the die member 1 composed of the divided die members 11 to 18, and the divided die members 11 to 18 are placed on the central axis of the cylindrical body A. On the other hand, the cylindrical body A is pushed and expanded in the radial direction by moving away from the radial direction, and tube expansion molding is performed.

  As shown in FIG. 3, the secondary finish pipe expansion is performed by increasing the number of divisions of the die member 1 from the primary pipe expansion and dividing the die members 11 to 19 equally into nine pieces in the circumferential direction and the primary pipe expansion. It comprises a cylindrical body A and an insertion rod (not shown).

  The secondary finishing pipe expansion is performed in the same manner as the above-mentioned primary pipe expansion, and the divided die is expanded in the radial direction to perform pipe expansion molding.

  By performing the above-mentioned two pipe expansion moldings, variation in molding can be reduced, and by using an odd number of divided die members in the final pipe expansion, the minimum diameter and the maximum diameter of the die member in the cylindrical body A do not come to symmetrical positions. Therefore, since the variation in the inner diameter can be minimized, the cylinder inner diameter accuracy of the cylindrical body can be increased in the present embodiment.

  Although the present embodiment has been described with two tube expansion moldings, the number of tube expansion moldings is not limited to this and may be performed a plurality of times.

(Embodiment 2)
FIG. 4 shows a method for finishing and expanding a cylindrical body according to Embodiment 2 of the present invention.

  In the present embodiment, as an example, it is assumed that the tertiary finishing pipe expansion is performed after the primary pipe expansion of FIG. 2 and the secondary pipe expansion of FIG.

  As shown in FIG. 4, for the tertiary tube expansion molding, the die member 1 is divided into nine equal parts in the circumferential direction and the divided die members 11 to 19 are rotated by an angle α in the circumferential direction after the secondary tube expansion. Are arranged from a cylindrical body A and an insertion rod (not shown). These divided die members 11 to 19 have the same outer peripheral surface as the inner peripheral surface of the cylindrical body A, and the inner peripheral surface is a tapered surface corresponding to an insertion rod (not shown).

  The operation of the third expansion is the same as the operation shown in the first embodiment.

  According to the present embodiment, the contact surface of the split die with respect to the cylindrical body A can be dispersed by rotating and expanding the cylindrical body by an angle α, so that the variation in the inner diameter can be reduced. As a result, the cylindrical inner diameter accuracy of the cylindrical body can be increased in the present embodiment.

  The angle α can be determined arbitrarily, but it is desirable to set the angle α to an appropriate angle according to the number of divisions of the division die.

(Embodiment 3)
FIG. 5 shows an assembly diagram of the cylinder and the electric motor according to Embodiment 3 of the present invention.

  For example, as shown in FIG. 5, when the number of slots of the motor is nine, the number of divided die members in the finish tube expansion molding is set to nine equal to the number of slots of the motor to be assembled and coupled, so that the motor is assembled and coupled. As a result, assembly distortion and air gap defects can be prevented, leading to stabilization of performance characteristics and noise characteristics of the hermetic electric compressor, and improvement of reliability.

  In the present embodiment, the number of divisions of the die member is equal to the number of slots of the electric motor, but the same effect can be obtained even when the number of divisions is a multiple of the number of slots of the electric motor.

  In Embodiments 1 to 3, the number of divisions in the finish expansion of the divided die member constituting the die member 1 has been described as nine, but the number of divisions of the divided die member is not limited to nine. Any odd number may be used.

  Further, in Embodiments 1 to 3, the pipe expansion molding has been described as an example, but the cylindrical accuracy of the cylindrical body can be improved with the same configuration for the tube contraction molding.

  The tube expansion or contraction molding method of the present invention has an effect of improving the cylinder accuracy of the cylinder, and is useful as a tube expansion or contraction molding method of a cylinder used for a sealed container of a hermetic compressor. It is.

Manufacturing process diagram of wound tube cylindrical body in embodiment 1 Sectional drawing of primary tube expansion molding in Embodiment 1 Sectional drawing of secondary finish tube expansion molding in Embodiment 1 Sectional drawing of finish tube expansion molding in Embodiment 2 Assembly drawing of cylindrical body and electric motor in embodiment 3 Cross-sectional view of a cylindrical body and a die member when a tube is formed by a conventional die

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Die member 11-19 Split die member 2 Die member 21-29 Split die member A Cylindrical body 3 Electric motor

Claims (1)

A die member that is divided into a plurality of portions in the circumferential direction is inserted into the inner peripheral surface or outer peripheral surface of the cylindrical body, and these divided die members are moved in the radial direction of the cylindrical body to expand or contract the cylindrical body. In the method of manufacturing a cylindrical body, in the above-described tube expansion or tube contraction molding in which the tube expansion or tube contraction is performed a plurality of times, the contact position of the divided die member with respect to the cylinder is determined in the circumferential direction for each tube expansion or tube contraction. a method of manufacturing a cylindrical member Ru varied,
A cylindrical body characterized in that the number of divisions of the divided die member is increased for each molding and tube expansion or contraction is performed, and tube expansion or contraction molding is performed with an odd number of segmented die members in the final finish molding. Production method.