JPS61289916A - Manufacture of pipe fitting with positioning pin - Google Patents

Abstract

PURPOSE:To improve dimensional accuracy and strength of products by forming a formed body consisting of a barlike body, central part, and connection part into a one-piece body and bending an end of the barlike body by a pressing part into a bent part having an extent which includes a spring back extent. CONSTITUTION:A steel formed body consisting of a center part 1, connection part 4, and a barlike body 5 is formed by cutting. Both end surfaces 6 and 7 of the central part 1 and the inside surface of a through hole 2 are finished accurately. The formed body is put on a fixing table 9 with an end surface of the central part 1 down and is fixed by a bolt 11 through a plastic washer plate 10. A groove 12 is formed on the side of the table 9 and the end of the barlike body 5 is bent by down movement of a pressing part 13. The groove 12 and a groove 14 are inclined with consideration for a spring back extent so that a parallelism of a positioning pin formed of the barlike body is improved. Both dimensional accuracy and strength of products are improved because of the one-piece forming.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a method for manufacturing a pipe joint with positioning pins, and can be used, for example, to manufacture a pipe joint with positioning pins used in a flow path for brake oil or the like.

[Prior Art] A conventional manufacturing method for a pipe joint with a positioning pin involves manufacturing the positioning pin 26, a pipe joint consisting of the central part 20 and the connecting part 23 as separate parts, and then brazing, caulking, friction welding, etc. It was integrated in this way. And sometimes the installation is
As shown in FIG. 4, positioning is performed by fitting a single-shaped positioning pin 26 into a hole in a member 30 to be mounted.

Therefore, in view of sealing performance and positioning accuracy, the axial direction of the positioning pin 26 and the central axis of the through hole 21 in the central portion 20 are required to have highly accurate parallelism. Also, the central part 20
Both end surfaces where the through hole 21 opens and the inner circumferential surface of the through hole 21 are finished by precision machining.

[Problems to be Solved by the Invention] Pipe joints with positioning pins obtained by the above-described conventional manufacturing method may not have sufficient strength when brazing is used. Furthermore, the caulking method may result in poor accuracy, and the friction welding method has the respective drawbacks of molten fringes. And since the number of parts is 2,
There are problems in terms of cost and process.

In addition, when attempting to manufacture a pipe joint with a locating pin from a single piece, it is difficult to process both end faces of the center part and the inner circumferential surface of the through hole precisely with the locating pin bent in a single-shape shape. This is difficult, and machining the positioning pin into a single-curved shape results in a large loss of material. Therefore, after the cutting process, a step of bending the linear rod-like body into a single character shape is required. However, this method has not been used in the past because it causes problems such as poor accuracy due to springback during bending, and poor sealing performance due to scratches on both end surfaces where the central through hole opens. do not have.

In view of the above-mentioned problems, the inventors of the present invention have conducted extensive research and have discovered a method for manufacturing a pipe joint with positioning pins as an integral product.

[Means for Solving the Problems] -4- The method for manufacturing a pipe joint with positioning pins of the present invention includes a central portion having a through hole into which a perforated bolt is fitted, and a central portion extending from the central portion and having a through hole in which a perforated bolt is fitted. A molding step of integrally molding a molded body consisting of a connecting part having a fluid passage communicating approximately perpendicularly to the central axis of the body, and a rod-shaped body extending approximately perpendicularly to the central axis from the central part; a fixing step of fixing the central part to the fixing base so as to be perpendicular to the surface of the fixing base; and pressing the end of the rod-shaped body protruding from the fixing base with a pressing member to connect the central axis and the end. and a bending step of further bending the end portion from a position parallel to the axial direction by an amount corresponding to the springback of the end portion.

The molding step is a step of manufacturing a molded body used in the manufacturing method of the present invention. The molded body has a central part with a through hole,
It is composed of a connecting part with a fluid passage and a rod-shaped body that becomes a positioning pin by being bent in the pressing process described below.

In the forming process, the above-mentioned compact is formed by cutting, cold forging, or the like. When installing a pipe joint with a locating pin, the central part 2 is
The perforated bolt 22 fits into the through hole 21 of 0, and the connecting part 2
A flow path is formed in communication with the fluid passage 24 of No. 3. Therefore, in order to prevent fluid leakage, the inner peripheral surface of the through hole 21 is precisely machined in this molding process. Also, one end surface of both end surfaces where the through hole 21 of the central portion 20 is opened comes into contact with the attached member 30 of the disc brake body via the copper gasket 25.
The other end surface serves as a sealing surface that comes into contact with the head of the perforated bolt 22, and is similarly precisely machined in the molding process to prevent leakage.

In the molding process of the manufacturing method of the present invention, the rod-shaped body serving as the positioning pin 26 is linear, and precision machining of the portion corresponding to both end surfaces and the inner peripheral surface of the through hole 21 is easy.

The fixing step is a step of fixing the molded body to a fixing table as a preparatory step for the bending step. In this fixing step, it is necessary to fix the molded body so that the central axis of the through hole in the center of the molded body is perpendicular to the surface of the fixing table. This allows the bending direction of the rod-shaped body end to be easily determined. It is also necessary to fix the center part so that both end faces are not damaged. Needless to say, this cleans the surface by removing chips, dust, etc., but it is desirable to interpose an elastic material, such as resin or rubber, which is softer than the material of the molded body.

However, if a thick soft elastic material such as resin or rubber is used, the fixing force will be too relaxed, which may cause problems such as movement of the molded product during the bending process. Therefore, it is desirable that the elastic body be thin and film-like. Furthermore, in order to prevent the molded body from moving during the bending process and resulting in insufficient precision, it is necessary to securely fix the molded body. In order to do this, for example, it is preferable to fit a bolt into a through hole and fix it by screwing it to a fixing base.

The bending step is a step of bending the end of the rod-shaped body protruding from the fixing base into an L-shape so as to be parallel to the central axis of the through hole. If the material is simply bent parallel to the central axis, there will be a return called springback, and parallel accuracy cannot be obtained. Therefore, in the present invention, the end of the rod-shaped body is further bent from a position parallel to the central axis so that it becomes parallel due to springback. In order to do this, for example, the side surface of the fixing base is formed so as to extend inward by the amount of springback from a position perpendicular to the surface of the fixing base to which the center portion of the molded body is fixed. In other words, the springback is caused by the large tip of the rod,
The side surface of the fixing base is tapered. Alternatively, the side surface portion of the suppressing member is formed into a tapered shape that protrudes outward by the amount of springback from a position perpendicular to the surface of the fixing base to which the center portion of the molded body is fixed. As a result, the end of the rod-shaped body is bent at an acute angle deeper than the position parallel to the central axis of the support through hole, and then becomes parallel to the central axis due to springback. Further, it is desirable to provide a groove in at least one of the side surface of the fixing base or the side surface of the pressing member, the inner wall surface of which is parallel to the central axis of the through hole. By fitting the end of the rod-like body into this groove and bending it, the inner wall surface becomes a locking portion to restrict the movement of the rod-like body in the direction perpendicular to the bending direction, thereby making the parallelism more precise. In this case, the bottom of the groove is tapered to allow for spring back. In addition to the groove, it is also possible to partially provide a locking portion protruding from the side surface.

The bending process may be performed while heating, but by performing the bending process at room temperature, there is no fear of deformation due to heat, and accuracy is further improved.

[Operations and Effects of the Invention] In the manufacturing method of the present invention, the ends of the rod-shaped bodies are bent in anticipation of springback. Therefore, the bent end of the rear rod-like body returns slightly due to springback and becomes parallel to the central axis of the through hole in the central portion. By forming at least one side surface of the fixing base or the pressing member to follow the end of the rod-like body when bent, the central axis of the through-hole in the center is parallel to the end of the rod-like body. , accurately and easily obtained. Therefore, according to the manufacturing method of the present invention,
It becomes possible to manufacture a pipe joint with positioning pins from an integrally molded body, and the resulting pipe joint with positioning pins has good precision and excellent strength.

[Example] This will be explained in detail below using examples.

First, a molded body as shown in FIG. 3 was manufactured by cutting a steel material. This molded body has an inner diameter of 10 mm in the center part 1.
A through hole 2 is provided on one side of the central portion 1, and a base portion 4, which is the connecting portion, is provided on one side of the central portion 1 and has a fluid passage 3 that communicates with the through hole 2 and is perpendicular to the central axis of the through hole 2. . Also, central part 1
A cylindrical rod-like body 5 with a diameter of 5 mm is formed on the opposite side of the mouthpiece 4 . The end surface 6.7 of the central portion 1 where the through hole 2 opens and the inner circumferential surface of the through hole 2 are precisely machined.

As shown in Fig. 1, the molded product processed in this way is
The central part 1 is placed with one end face down on a fixed base 9 whose surface is coated with fluororesin 8, and the resin seat plate 10 is
It was fixed with bolts 11 through. At this time, the surface of the fixing table 9 is horizontal, and the central axis of the through hole 2 is perpendicular to the fixing table 9. Further, a groove 12 is provided in the side surface of the fixing table 9, and the bottom of the groove 12 is tapered so as to form an angle smaller than 90 degrees with respect to the horizontal surface of the fixing table 9.

The pressing member 13 has a groove 14 in which the rod-shaped body 5 fits in the pressing part, receives the force of the hydraulic cylinder 15, is guided by a guide member 16 fixed perpendicularly to the base, and is pushed against the surface of the fixed base 9. is configured to move vertically. The end portion of the pressing member 13 having the groove 14 forms an angle greater than 90 degrees with respect to the surface of the fixing base 9, and moves while fitting into the groove 12 of the fixing base 9 as shown in FIG.

Using the pressing member 13 described above, the end of the rod-shaped body 5 of the fixed molded body was bent along the grooves 12 and 14 by moving the pressing member 13 downward. Note that the bending was performed at room temperature. At this time, the end of the rod-shaped body 5 has an acute 1-character shape that forms an angle smaller than 90 degrees. Then, when the pressing member 14 is moved upward, the end of the rod-shaped body 5 returns slightly due to springback, and the rod-shaped body 5
The angle between the end and the surface of the fixing base 9 was 90 degrees, and the central axis of the through hole 2 and the end of the rod-shaped body 5 were parallel to each other.

The obtained pipe joint with positioning pin had no scratches on both end surfaces of the central portion, and the parallelism between the central axis of the through hole and the positioning pin was manufactured with high precision.

[Brief explanation of the drawing]

1, 2, and 3 relate to the manufacturing method of the embodiment of the present invention, FIG. 1 is a front view showing a device for fixing and bending the molded product, and FIG. 2 is the fixing method shown in FIG. 1. FIG. 3 is a cross-sectional view showing the rod-shaped body being bent by fitting the base and the pressing member, and FIG. 3 is a front view in cross-sectional view of the molded body obtained by the molding process. FIG. 4 is a cross-sectional view showing a positioning pin-equipped pipe joint obtained by a conventional manufacturing method. 1.20...Central part 2.21...Through hole 4.2
3... Connecting portion 5... Rod-shaped body 8... Fluororesin layer 9... Fixing base 13... Pressing member 10.
...Resin seat plate 12.14...Groove

Claims (6)

[Claims] (1) A central portion having a through hole into which a perforated bolt fits;
A molded body consisting of a connecting part extending from the central part and having a fluid passage communicating substantially perpendicularly to the central axis of the through hole, and a rod-shaped body extending from the central part substantially perpendicularly to the central axis is integrally molded. a fixing step of fixing the central portion to the fixing base so that the central axis is perpendicular to the surface of the fixing base;
a bending step of pressing the end of the rod-shaped body protruding from the fixing base with a pressing member and further bending the end by the amount of springback from a position where the central axis and the axial direction of the end are parallel; A method for manufacturing a pipe joint with a positioning pin, characterized in that: (2) The side surface toward the end of the rod-shaped body of the fixed base is tapered inward from a position perpendicular to the surface of the fixed base to which the central part is fixed, and the side surface extends along the side surface. A method of manufacturing a pipe joint with a positioning pin according to claim 1, wherein the end portion is bent. (3) The side surface of the pressing member toward the end of the rod-shaped body has a tapered shape that protrudes outward from a position perpendicular to the surface of the fixed base to which the central portion is fixed, and the side surface extends along the side surface. A method for manufacturing a pipe joint with a positioning pin according to claim 1, wherein the end portion is bent. (4) A groove is provided in at least one of the side surface of the fixing base or the side surface of the pressing member, and the inner wall surface is parallel to the central axis of the through hole, and the rod-shaped body is bent along the groove. A method for manufacturing a pipe joint with a positioning pin as described in item 1. (5) The manufacturing method according to claim 1, wherein the fixing step is performed by sandwiching the opening ends of the through hole via an elastic body. (6) The bending process is carried out at room temperature.
The manufacturing method of the pipe joint with positioning pin described in .