JPH0230340A - Method for spinning cylinder body - Google Patents

Abstract

PURPOSE:To prevent a sharp edge from being generated on the inner end of the inside diameter side of a joining tube part by moving mandrel to decide the inside diameter of the joining tube part relatively to the axial direction when the end part of a cylinder body is spun by a spatula. CONSTITUTION:While a rotating means 14 is rotated by the drive of a motor 17, the spatula 4 is pushed against the outer circumference of the other end part of the cylinder body 1. The cylinder body 1 is spun and deformed to form the joining tube part 2 by the pressing force of the spatula 4 until the other end part of the cylinder body 1 is brought into contact with the mandrel 5. The joining tube part 2 formed by the spinning operation is extended in the axial direction (in the direction of an arrow A) but the mandrel 5, too, moves in the axial direction with the extension of the joining tube part 2. Consequently, the contact part of the joining tube part 2 to the mandrel 5 is not pulled by the fractional force in the direction opposite to the extension direction of the joining tube part 2 and sharp edges can be prevented from being generated at the inner end of the inside diameter side of the joining tube part 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for drawing a cylindrical body, which is used when forming a small-diameter connecting pipe portion at the end of the cylindrical body.

(Prior Art and Problems to be Solved by the Invention) Generally, in the refrigeration circuit of an air conditioner, a filter is interposed in the middle of the piping for the purpose of removing dust contained in the circulating refrigerant.

As shown in FIG. 2, this filter is constructed by forming small-diameter connecting pipe portions 2.2 at the front and rear ends of a cylindrical body 1, and arranging a filter medium 3 within the cylindrical body I. There is.

As in the above-mentioned cylindrical body 1, the well-known spatula drawing process is often used as a method for forming the small-diameter connecting pipe portion 2 at the end thereof.

As shown in FIG. 3, the spatula drawing process is performed by rotating the cylindrical body 1 and pressing a spatula 4 against the outer circumferential surface of the end thereof to cause drawing deformation. At this time,
A core rod 5 located concentrically with the cylindrical body 1 is exposed on the end side of the cylindrical body 1, and the inner diameter of the connecting pipe portion 2 formed by the drawing process as described above is as follows. The outer diameter of the core rod 5 is determined by the outer diameter of the core rod 5. On the other hand, in the spatula drawing process as described above, the area where the spatula proofing has been performed, that is, the connection pipe portion 2, is determined by the outer diameter of the core rod 5. ) will extend in the axial direction (i.e., in the direction of arrow A), but the contact area between the connecting pipe portion 2 and the core rod 5 will extend in the opposite direction (i.e., in the direction of arrow B) due to the frictional force between the two. You will be pulled. As a result, a sharp edge 6 is formed at the inner end line on the inner diameter side of the connecting pipe portion 2. Since the sharp edge 6 is difficult to remove even after the spatula drawing process, it is usually used in a state where it remains. When fluid is allowed to flow through the cylindrical body l thus obtained, high-pitched sounds may be generated due to the influence of the sharp edges 6. In particular, when a cylindrical body subjected to the above-mentioned spatula drawing process is used as a case for a filter in a refrigeration circuit for an air conditioner, the pressure of the circulating refrigerant may suddenly drop (for example, When switching from heating operation to defrost operation, etc., a noticeable high-pitched sound is generated.How to prevent the generation of such high-pitched noise is
This has become an important issue that needs to be solved in this industry, where there is a strong demand for reducing the operating noise of air conditioners.

The present invention has been made in view of the above points, and is designed to prevent sharp edges from occurring at the inner diameter side of the connecting tube when forming a small diameter connecting tube at the end of a cylindrical body by spatula drawing. The purpose is to

(Method for Solving the Problem) In the present invention, as a method for solving the above problem, as shown in the drawings, the end of the material made of the cylindrical body l is
The core rod 5, which determines the inner diameter of the connecting tube section 2 which is drawn to form the connecting tube section 2 with a small diameter, is relatively moved in the axial direction.

(Effects of the Invention) According to the method of the present invention, when the end of the material made of the cylindrical body l is drawn using a spatula 4 to form the connecting pipe portion 2 of a small diameter, the connecting pipe portion 2 Core rod 5 that determines the inner diameter of
Since the connecting tube 2 is made to move relatively in the axial direction, when the connecting tube section 2 extends in the axial direction during the spatula drawing process, the core rod 5 also moves in the axial direction as the connecting tube section 2 extends. The inner diameter portion of the connecting tube portion 2 is no longer pulled in the opposite direction to the extending direction due to the frictional force generated at the contact portion between the portion 2 and the core rod 5, and a sharp edge is generated at the inner end on the inner diameter side of the connecting tube portion 2. It has the excellent effect of eliminating

(Example) Hereinafter, a method for processing a cylindrical body according to an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a drawing device used in the method of the invention.

The drawing device includes a core rod 5 that is pivotally supported by a pair of bearings 12 and 13 that are placed opposite each other on a table +1.
and rotation means 14.

The core rod 5 determines the inner diameter of the small-diameter connecting pipe portion 2 formed at the end of the cylindrical body l by a spatula drawing process, and is pivoted so as to be slidable in the axial direction with respect to the bearing 12. supported. On the other hand, the rotating means 14 is equipped with a clamp mechanism 15 for gripping the cylindrical body l to be subjected to the spatula drawing process,
A pulley 16 pivotally attached to the rotating shaft 14a and a motor 1
A pulley I8 which is pivotally mounted on the drive shaft 17a of No. 7 is connected via a belt 19 so that power can be transmitted. and,
The core rod 5 is arranged to face concentrically within the end of the cylindrical body 1 gripped by the clamp mechanism 15 of the rotation means 14, and is spatula 4
is now being forced upon us.

The drawing device having the above-mentioned configuration performs a spatula drawing process on a cylindrical body in the following manner.

With one end of the cylindrical body 1 being gripped by the clamp mechanism 15 of the rotating means 14, the motor 17 is driven to rotate the rotating means 14 while the spatula 4 is held against the outer periphery of the other end of the cylindrical body 1. Press. Then, the pressing force of the spatula 4 causes the other end of the cylindrical body 1 to be squeezed and deformed until it comes into contact with the core rod 5, thereby forming the connecting pipe portion 2. In the above processing step, the connecting pipe portion 2 formed by the spatula drawing process extends in the axial direction (in the direction of arrow A) from the state before processing (shown by the chain line in Figure 1). The core rod 5 also moves in the axial direction. Therefore, the connecting pipe portion 2 and the core rod 5
This prevents the contact portion from being pulled in the direction opposite to the extending direction of the connecting tube portion 2 due to frictional force, and sharp edges do not occur at the inner end of the connecting tube portion 2 on the inner diameter side. Note that if the other end of the cylindrical body 1 is subjected to the same drawing process as described above, connecting pipes 2.2 of small diameter are formed at both ends of the cylindrical body 1 by the drawing process.

When the cylindrical body 1 obtained in this way is used as a filter case as shown in FIG. As a result, the treble level was lowered (down by about lodb).

[Brief explanation of the drawing]

Fig. 1 is a partially sectional plan view showing a drawing device used in the method of the present invention, and Fig. 2 is a longitudinal sectional view showing a filter which is an example of the use of a cylindrical body processed by the method of the present invention. , FIG. 3 is an explanatory diagram for explaining the conventional spatula drawing method. l......Cylindrical body 2...Connecting tube section 4... Spatula 5... Core rod

Claims (1)

[Claims] 1. The inner diameter of the connecting tube section (2) when the end of the material made of the cylindrical body (1) is drawn using a spatula (4) to form a small diameter connecting tube section (2). The core rod (
5) A method for drawing a cylindrical body, characterized in that the parts are moved relative to each other in the axial direction.