JPH0262099B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for forming a flanged shaft body, and more specifically, for example, a shaft body such as an intermediate joint of a brake hose for an automobile, etc., in which one side of the shaft body is wide. This relates to a heading forming method for a flanged shaft body in which the flange portion is used as a mounting piece.

(Prior art and its problems) FIG. 7 shows an intermediate joint having a ball-shaped flange of a brake hose for an automobile. 4 in the figure is a rice ball-shaped flange, two mounting holes 6, 6 are provided, and a shaft body (hereinafter also referred to as a shaft portion) 2 is integrated at a position 4a near the contour, off the centroid of the flange 4. It is set in. The shaft body 2 is hollow, and a conductive pipe 3 is inserted through the shaft body 2 and fixed by brazing at the center thereof.

A hose is inserted into the intermediate joint 1 inside the shaft portion 2, and the hose is caulked from the outside of the shaft portion 2 to serve as a joint for the hose. The flange 4 is fixed to the chassis of an automobile with nuts or the like by passing bolts through the mounting holes 6, 6.

The conventional manufacturing process of the intermediate joint having the rice ball-shaped flange of the brake hose for automobiles is as illustrated in the conventional method section of FIG. However, although the material to be used as the shaft body 2 is shown in a plan view in the press P1 and P2 steps, the other steps are shown in a side view.

Regarding the conventional method, each step will be explained according to the conventional method section in FIG.

<Material> First, a long cylindrical wire material W1 for cold heading
Prepare.

<Cutting> The long material W1 is cut into a bar-shaped material W2 of a predetermined length.

<Forward extrusion> The rod-shaped material W2 is pushed into a die, and forward extrusion is performed using a punch to form the material W2 into a thinner diameter on one side to form a material W4.

<Upsetting-Extrusion> Furthermore, the center of the shaft portion U2 is swollen to facilitate formation of a brim-like convex portion in a subsequent process. That is, the larger diameter side is squeezed by a die by extrusion molding, and the center of the shaft portion U2 is upset to compress the material W4 in the previous step to form a bulge U2a.

<Upsetting> Furthermore, the shaft portion U2 in the previous process is
Using a die that is symmetrical with respect to the axis l of the shaft portion U2, the brim-shaped convex portion U4 is caused to expand largely along the shape of the die. This is done to make it easier to form the flange portion in the subsequent press step. Note that the fibers of the material produced at this time (hereinafter also referred to as grain flow lines) run along the shape of the material, so they are approximately symmetrical with respect to the axis l.

<Press P1> After the above-mentioned <upsetting> process is completed, after performing appropriate heat treatment, etc., cold forming is performed on the flange-shaped convex portion U4 using a press machine. At this time, the excess thickness U8 is formed to expand in a substantially circular shape around the shaft portion U2.

<Press P2> Next, in order to make the flange portion U6 into a predetermined size and shape, the excess thickness U8 is trimmed using a punch and a die, and further, a hole is punched in order to make a mounting hole U10.

Then, after finishing the cutting process using an NC machine and the brazing process of the conductive path, the product is made as shown in Figure 7.

As explained above, in the conventional method, a mold that is symmetrical about the axis l is usually used in order to minimize the deformation resistance of the material in the upsetting process and extend the life of the mold. However, the grain flows processed and formed in this manner run around the collar-shaped convex portion U4 during the upsetting process. Furthermore, this becomes more noticeable during subsequent press forming, and as shown in FIG. 5B, the grain flow line U5 runs in a large undulating manner in two directions perpendicular to the axis 1 at the flange portion. Therefore, after trimming the excess thickness U8 as shown in FIG. 2B, the edge U of the flange portion U6 where the shaft portion U2 is located.
Since the grain flow line U5 is divided at 6a, this part has a problem of being weak in strength and prone to cracks. In addition, as described above, the brim-shaped convex portion U4 is formed symmetrically with respect to the axis l,
On the other hand, since press forming is performed, a large amount of excess thickness U8 is formed, resulting in poor material yield. Furthermore, the press pressure at this time requires an unnecessarily large load due to the formation of a large amount of excess thickness U8.

(Problems to be Solved by the Invention) Therefore, the present invention is an attempt to solve the above-mentioned problems of the conventional method. The problem to be solved is to provide a method for cold heading of a flanged shaft body in which grain flow lines are not separated on the surface.

(Means for Solving the Problems) The means of the present invention for solving the above-mentioned problems is to cold-process a flanged shaft body provided with a flange having a wide portion on one side of the shaft body from a shaft material. A method of forming by forging, which includes an end face straightening step of straightening both end faces of a cut shaft to a predetermined length, and a flange-shaped protrusion on one side perpendicular to the axis of the shaft by forging. a flange-forming step in which the flange-like protrusion is formed by pressing, a flange-forming step in which the flange-like protrusion is formed into a flange shape having a wide portion on one side; It is said to be a heading forming method for flanged shaft bodies, which consists of a trimming process in which excess thickness is trimmed by press working.

(Function) The function of the present invention consisting of the above steps will be explained in comparison with the conventional method shown in FIG.

In the conventional method, the cut rod-shaped material was suddenly forged by <forward extrusion> to <upsetting>, resulting in large variations in the length of the forged product. In the present invention, both end faces of the rod-shaped material cut in the end face straightening process are pressed from both sides with a punch in a predetermined die to obtain a predetermined length and both end faces are adjusted, thereby eliminating variations in the length of the finished product. can be made smaller.

Next, in the process of forming the flange-like convex part, for example, as shown in the <upsetting> process of FIG.
In order to make the bulge I2a at the center of 2 protrude in one direction perpendicular to the axis, a die asymmetrical with respect to the axis 1 is used to upset the bulge I2a to form a flange-like convex portion I4. The grain flow lines generated at this time are different from the grain flow lines generated in the conventional method of <upsetting>, and are along the axis l along the surface shape of the material.
It will run asymmetrically.

Next, a flange forming process is performed.

For example, the flange-like convex portion I4 as shown in the <upsetting> step in FIG. 1 is cold-formed using a press machine. That is, as shown in the <press P1> step in FIG. 1, the flange portion I6 is formed,
The extra thickness I8 is formed to spread almost uniformly along the outer periphery of the flange I6.

The flange-shaped protrusion I4 formed by the flange-shaped protrusion forming step requires a smaller area to be subjected to press pressure than that formed by the <upsetting> step of the conventional method.

Next, a trimming process is performed to remove excess thickness generated in the flange forming process. That is, the above-mentioned excess meat I8 is removed using, for example, a die and a punch. At this time, since the excess thickness I8 is much smaller than the excess thickness generated by the conventional method, the load for trimming can also be reduced.

Moreover, as shown in FIG. 2A, the grain flow line I5 after trimming the excess thickness I8 at this time is not separated at the edge I6a of the flange portion I6 where the shaft portion I2 is located. Therefore, it is strong against tensile stress in the direction perpendicular to the shaft portion I2 of the flange portion I6, and is less prone to cracking unlike the conventional example.

(Embodiment) A first embodiment of the present invention will be described below, mainly referring to FIGS. 3 to 7.

In this embodiment, as already explained using FIG. 1, a case will be described in which an intermediate joint of a brake hose for an automobile is formed.

This example differs from the conventional method in that it includes an <end face straightening> step and <
The upsetting> process and the <pressing P1, P2> process are different, and the other processes are almost the same.

The parts former of the automatic cold forging press sequentially performs the following steps: cutting → end face straightening → forward extrusion → upsetting → extrusion → upsetting. Note that the transfer of materials from one process to another is carried out appropriately by the robot's hand.

A to D in FIG. 3 are each process continuously performed in the above part former and the grain flow line I5a for each process.
- I5d is schematically illustrated.
Note that, as shown in FIG. 1, the material W2 is cut from the long material W1, so the material W2 has already been cut from the long material W1.
The grain flow line runs in the direction of the axis l. This grain flow line is an illustration of a cross-section of the material that was precisely polished and then immersed in a corrosive solution such as hydrochloric acid.
Each step will be explained in detail below.

<Cutting (see Figure 1, section of the first embodiment of the present invention)> Long material (material SWCH15AS, outer diameter 14.4 mm)
Cut W1 to a length of about 75.8mm and make the shaft body I.
2 material W2. The weight of material W2 is approximately 87.5
It is g. In the conventional method, heading molding is performed using a die that is symmetrical about the axis l, so the material cut in this process is, for example, 16.8 mm, length 64 mm, and weight approximately 110 mm.
g is required. Therefore, this embodiment saves about 18.6% of the material received.

<End face correction (Figure 3A)> In order to minimize the variation in length of the forged product, correction is performed so that both end faces are flat and the length of the material is constant. That is, after the cutting process, a material 10 with uneven end faces and length is pushed into a fixed die 22 having a predetermined inner diameter by a punch 20 with a predetermined stroke length to make both end surfaces of the material 10 flat. to correct. After this correction, material 10
is in a state of being crimped to the die 22, so the punch 20 is moved back from the die 22 to the left side in FIG.
extrude from The material 10 is checked by the robot's hand and handed over to the next process.

At this time, the grain flow line I5a runs straight in the axial direction, almost unchanged from the state before machining (the third
(See the grain flow diagram in Figure A).

<Forward extrusion (FIG. 3B)> The material 10 has a predetermined inner diameter, is extruded from the left side in FIG. 3B with a punch 26 using a fixed die 28, and the diameter of one side is narrowed to form 10b.
shall be. The diameter of the other side 10a is slightly thicker than in the previous step, but it is slightly longer overall.
Even after forward extrusion, the material 10 is still crimped to the die 28, so the pin 30 is used to push the material 10 into the die 28.
Push it out to the left side of the figure. The material 10 is checked by the robot's hand and handed over to the next process.

The grain flow line I5b at this time is almost the same as in the previous process, except that it is slightly constricted at the circumferential portion where the diameter becomes thinner (see the grain flow diagram in FIG. 3B).

<Upsetting - Extrusion (Fig. 3 C)> After the material 10 is set in the fixed die 36, the material 10 is extruded by the die 34 facing the die 36 and the diameter of one side is reduced to 10c. Further, the die 34 and the die 36 are used to make the upsetting 10d. At this time, the pin 32 is the material 10
is always urged toward the die 36 by a spring (not shown).

In this process, the material 10 has a slight bulge in the center where the flange is formed so that it can be easily deformed in the subsequent process, so the grain flow line I5c also changes slightly as it swells, but this bulge is not that large. Rather, the change in the grain flow line I5c is small (see the grain flow diagram in FIG. 3c). Therefore, material 10
The overall length of the process is longer than that of the previous process.

At this time, the material 10 is in a crimped state with the dies 34 and 36, so the die 34 slides to the left in the figure while being pressed by the pin 32 on the 10c side of the material 10, and then the material 10 is pushed out by the pin 38. The material 10 is checked by the robot's hand and handed over to the next process.

<Upsetting (FIG. 3 d)> After the material 10 is set on the fixed die 44, the opposite die 42 of the die 44 is slid toward the die 44, and the material 10 is inserted into the die 42. Then punch 40 and die 44
Compression molding is performed in the axial direction of the material 10 to the side. Conventionally, in order to reduce the deformation resistance during this process, upsetting is performed not only in one direction with respect to the axial direction, as in 10f, but in both directions. In this embodiment, the grain flow line 15d is placed on one side (1
0i side) and the other side (10
J side) is not significantly deformed (see the grain flow diagram in Figure 3D).

After the <upsetting> process, in order to suppress decarburization as much as possible, it is annealed in an atmospheric gas heat treatment furnace, then subjected to pickling, bonding, etc., and then cold-formed in a pressing process.

Next, the pressing process will be explained using FIG. 4.

FIGS. 4A to 4D schematically illustrate the press molding and trimming steps, and are longitudinal cross-sectional views of essential parts.

As shown in FIG. 4A, the material 10 is set in a permanently fixed lower die 54. At this time, the pin 56 is urged toward the upper die 50 side. Note that 52 is the upper mold 50
This is the pin located at .

Next, as shown in FIG. 4B, the upper mold 50 and the pins 52 move toward the fixed lower mold 54, and compression molding of the material 10 is performed. At this time, in the conventional method, a flange-shaped convex portion 10h like the 10i side is formed on the 10j side of the material.
(see FIG. 4A), the load area of the press is wide, and in this case, a load of about 520 tons is required, for example. On the other hand, in this example, only 240 tons is needed because the necessary parts are pressurized. Therefore
It becomes possible to mold using a 250-ton press machine.

Next, as shown in FIG. 4C, after press forming, the upper die 50 and pins 52 are first separated from the material 10,
Return to original position. On the other hand, the material 10 is extruded by the pin 56 located in the lower die 54 and proceeds to the next step.

Next, the trimming process will be explained.

As shown in FIG. 4D, the material 10 is cut into a die 58
Excess meat I created by press molding
8 is trimmed by a punch 60. At this time, in this example, the extra thickness I8 is small and can be made almost uniformly around the flange portion, so the load can be small (for example, a 45-ton press is sufficient), so that the mounting hole can be punched at the same time as the trimming.

FIG. 5A shows the grain flow line I5 before trimming the excess material after press forming. As already mentioned in the <upsetting> process, the grain flow wire I5 is processed so that it is greatly undulated only on one side of the flange with respect to the axis, so even after press forming, the flange does not protrude. small part 10
The waviness of the grain flow line of k is small, and the grain flow line will not be divided even if the excess thickness is trimmed. Therefore, the tensile strength in the protruding direction of the flange portion in the 10k portion after trimming is much larger than that in the conventional method (see FIG. 5B).

As shown in FIG. 6A, after the pressing process, the shaft portion 2, etc. is cut using an NC machine.
Passage 2a so that hoses and conduction paths can be installed
and 2b.

Next, as shown in FIG. 6B, the conduit 3 is connected to the passage 2b.
It is fixed by brazing, and a product with an intermediate joint as shown in Fig. 7 is completed. The wide side of the flange of this intermediate joint product is used as an attachment piece, and is attached to the chassis of an automobile and used as a brake hose joint.

Next, a second embodiment of the present invention will be described with reference to FIGS. 8A and 8B.

FIG. 8B is a perspective view of an intermediate joint with an oval flange of an automobile brake hose.
In FIG. 8B, 64 is a flange portion provided with a mounting hole 68, and a hollow shaft portion 62 is integrally provided near a position 64b off the centroid of the flange surface 64a and near the contour. A conductive tube 63 is fixed to the inner side of the shaft portion 62 at the center of the shaft portion 62 by brazing.

The second embodiment differs from the first embodiment only in the shape of the flange portion and the required amount of material, but has substantially the same operation and effect, so a description of each step will be omitted.

FIG. 8A shows the excess thickness 6 after press forming in the second embodiment.
FIG. 6 is a plan view before trimming No. 6; In addition,
FIG. 9 is a plan view of the case produced by the conventional method.

In the second embodiment, the outer diameter is 16.6 mm, the length is 45 mm,
If a bar-shaped material weighing 77g is forged and then press-formed, a press load of approximately 160 tons is required. However, when performing similar work using conventional methods,
A press load of 400 tons is required, and the second embodiment also has a small press load, which is convenient.
Furthermore, the extra thickness 66 of the flange portion 64 of the second embodiment
Its area is small (see Figure 8A), and it has the advantage that trimming and mounting holes can be done simultaneously using a 45-ton press machine. Moreover, even if the excess thickness 66 is trimmed, the grain flow lines will not be separated as in the first embodiment, and a flanged shaft body with high strength can be completed.

(Effects of the Invention) The present invention provides a flange-like convex portion for flange forming only on one side perpendicular to the axis of a rod-shaped material adjusted to a predetermined length as a pre-process for cold forming the flange portion by press working. Since it is characterized by being formed by forging, the following effects are expected.

That is, according to the present invention, (a) the flange-like protrusion only needs to be formed in one direction with respect to the shaft, so material can be saved considerably and yield can be improved; (b) Since the grain flow lines are not separated at the edge of the flange where the shaft body is located, the tensile strength in the direction perpendicular to the axis of the flange can be made stronger than products manufactured by conventional methods. ) When performing cold forming by press working, the pressurized area of the brim-like convex part is small, so the load is small, and the excess thickness is small, so it is necessary to perform hole punching when trimming, for example. In this case, the following effects can be achieved: trimming and hole punching can be performed at the same time.

[Brief explanation of drawings]

Fig. 1 is a comparison diagram of the manufacturing process of the first embodiment of the present invention and the conventional method, Fig. 2A is a grain flow diagram of the forged product according to the present invention, and Fig. 2B is the forged product according to the conventional method. Figures 3 to 7 show the first embodiment of the present invention, and Figures 3A to 3D show operation explanatory diagrams of the forging process and grain flow diagrams of the materials in each process. 4
Figures A to D are explanatory diagrams of the operation of the pressing process, Figure 5A is a grain flow diagram of the material before trimming of excess material after press forming in the first embodiment, and Figure 5B is after press forming in the conventional method. Fig. 6A is a longitudinal sectional view of the main part of the material after the cutting process, and Fig. 6B is a longitudinal sectional view of the main part of the material after the brazing process of the conduit pipe. , FIG. 7 is a perspective view of a ball-shaped intermediate joint of an automobile brake hose, FIGS. 8A and B are explanatory views of the second embodiment of the present invention, and FIG.
The figure is a plan view of a material having an oval-shaped flange before trimming the excess material after press forming using a conventional method. 2... Shaft body (shaft part), 4... Flange, I5, I5
a, I5b, I5c, I5d, U5... grain flow line, 1
0...Material.

Claims (1)

[Scope of Claims] 1. A method for forming a flanged shaft having a flange having a wide portion on one side of the shaft by cold heading from a shaft material, the method comprising: an end face straightening process for correcting both end faces to a predetermined length; a flange-shaped protrusion forming process for forming a flange-shaped protrusion on one side of the shaft perpendicular to the axis by forging; A flange forming process in which the part is formed into a flange shape having a wide part on one side by press working, and a trimming process in which the excess thickness created in the flange forming process is trimmed by press working. Heading method for flanged shaft body.