JPS5937138B2 - Processing method for U-shaped joints in vehicle steering joints, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of machining a U-shaped joint for connecting a shaft in a vehicle steering joint (universal joint) or the like.

Generally, the steering joint of a vehicle consists of a steering shaft connecting joint 1 of the steering wheel and a wheel side connecting joint 2, as shown in Fig. 1.The steering shaft connecting joint 1 is a U-shaped joint into which the steering shaft is inserted and connected. 3, and a pair of ball receiving parts 4 extending integrally from one side of the U-shaped joint part 3, and the U-shaped joint part 3 has reinforcing bent parts 5 bent inward at both ends. The end face of the reinforcing curved portion 5 and the U-shaped curved wall form a cylindrical portion 6 for inserting a steering shaft, and the steering shaft inserted into the cylindrical portion 6 is inserted through the reinforcing portion 5. Tightening screw hole 7
We are trying to strengthen the bolt-tightening installation.

The reinforcing bent portion 5 is essential for adding strength to the U-shaped joint portion 30 and for forming the inner wall of the cylindrical portion 6 for inserting the steering shaft.

Conventionally, when processing the above-mentioned U-shaped joint, basically, as shown in Fig. 2, a prototype plate 1a as shown in Fig. A is made by punching from a steel plate, and then a plate 1a as shown in Fig. B is attached to both ends of the original plate 1a. A reinforcing curved portion 1b is formed by bending the reinforcing curved portion 1b multiple times as shown in FIG. It was processed into a perfect circle.

As mentioned above, in order to process the reinforcing curved portion 1b, the conventional product bends the plate material multiple times to perform a 180° bend.
Cracks or destruction of the internal metal structure often occur in the bent portion P1, and its processing requires advanced bending technology and skill.

Since the cracks mentioned above become more pronounced as the thickness of the plate increases, the setting of the thickness involves a contradiction in that workability must always be taken into consideration.

As mentioned above, the reinforcing bent part 1b belongs to the processing part where safe mounting is important as a joint for the steering shaft of the steering wheel.
Preventing the above-mentioned cracks is also considered to be an important technical issue in terms of processing.

In addition, since the bending allowance of the reinforcing curved part and the outer shape of the ball receiving part are processed by punching, the material yield is poor (and the cost increase is also a problem in mass production, along with the large number of processing steps) It is said that

In addition, when the reinforcing curved portion 5 is formed by the above bending process, it is unavoidable to generate a narrowed edge portion P2 on the side wall of the bent portion P1 during the process, and this portion imparts a sliding bend to the material structure. This may lead to a decrease in strength, and the neck portion P2
overlaps with the drilling position of the tightening screw hole 7, as shown in Fig. Contains important issues.

The present invention aims to obtain a finished product by employing a forging press method in the processing of the above-mentioned steering joints, etc. For a unit material made of a steel plate with a wall thickness necessary for reinforcement,
By applying the prescribed forging and bending processes described later, U
This relates to a new method for manufacturing a U-shaped joint with an L-shaped joint and a ball receiving part, and involves a method for manufacturing a conventional U-shaped joint,
In particular, the reinforcement part and a part of the inner wall necessary for inserting the steering shaft are formed by the thickness of the material itself and by adding thickness by forging, without relying on the bending part, and the cylindrical part for inserting the shaft is formed by adding thickness by forging. The aim is to provide a processing method for appropriately rounding out the round shape, completely eliminating the problems in processing and use of conventional U-shaped joints, especially the most problematic crack generation phenomenon, and reducing the number of man-hours. This makes it possible to reduce costs and improve yield.

) The drawings from FIG. 3 onwards show optimal embodiments of the present invention.

As shown in FIG. 4, a steel plate having a thickness necessary for reinforcement is prepared as a unit material 10, and a ball-receiving plate portion 11 is formed from this by forging.

At the same time, thick portions 12a are symmetrically formed on both ends of one side of the joint plate portion 12, and thin portions 12b are formed between the thick portions by the forging described above.

Cold forging press is applied as the most preferable forging method.

FIG. 6A shows a forging method showing the processing of the joint processing plate portion 12, in which the forging and forming pressure of the forging dies 13 and 14 is concentratedly applied to the thin wall portion 12b, and the thick wall portion 12a is processed without mold restrictions.

As far as this part is concerned, the open die forging method among the so-called forging methods is applied.

Through this forging process, the thin wall portion 1 is formed into the joint processed plate portion 12.
2b and the thick wall portion 12a, a warp α is generated in at least the cylinder inner thick portion 12a toward the exposed side, and a portion where the cylinder inner thick portion 12a and the thin wall portion 12b are connected is processed. A slope 12c curved in the concave direction is formed.

At the same time, the material is expanded in the plane direction by the forging process, and an increase in the thickness of the thick portion 12a is observed, and the material 1
A slight thickness is added to the zero material thickness.

For example, for a material (steel plate) between 10 and 10 in thickness, 600t to 10
When the above-mentioned open die forging process is performed with a very small forging pressure of 00t and the thin wall part 12b is processed to approximately 6 mm, the wall pressure part 1
2a was 10mTfL but now it is 10.57n11L
It was observed that the thickness increased to ~117IL7IL.

In this way, a blank product including the ball receiving plate portion 11 and the joint plate portion 12 as shown in FIG. 5 is forged.

Next, this is subjected to several U-shaped bending processes starting from the thin wall portion 12b to form a U-shaped joint 1' having a U-shaped joint part 12' and a pair of ball receiving parts 11'. A reinforcing thick part 12a' which is thickened inwardly by the thick part 12a is machined at the end of the part 12, and at the same time, the inner bottom surface 12
c' forms a part of the inner wall of the cylindrical part 15 for insertion of the steering shaft.

This reinforced thick part 12a' is different from that formed by a reinforced bent part as in the conventional product, and is formed by the thickness of the thickened material itself, and when considering the embrittlement of the conventional bent part, It has been recognized that the reinforcing strength can be significantly increased even if the wall thickness is smaller than the overlapped wall thickness, and furthermore, the inner wall of the cylindrical portion 15 for insertion of the steering shaft is thinner than the thin wall portion 12.
It is formed of a U-shaped curved wall 12b' by U-shaped curved wall 12b' and a reinforcing thick part 12a' made of the material itself that expands from there, and this holds the steering shaft, so it is possible to significantly improve the holding strength of the shaft. becomes.

The inclined surface 12c formed at the continuous part of the thick part 12a and the thin part 12b is formed when the thin part 12b is given a U-shaped bending process.
An inner wall surface is formed that is substantially in line with the inner cylindrical shape of the U-shaped curved wall 12b'.

That is, by forming the inner bottom surface 12c' of the reinforcing thick portion 12a' by the inclined surface 12c, post-processing of the cylindrical portion 15 for insertion of the steering shaft becomes extremely advantageous.

Similarly, since the warp α is formed in the thick portion 12a by forging, the bending posture and position are determined in advance, which greatly simplifies the bending process as a post-process.

Furthermore, the joint 1' formed in this way is connected to the above-mentioned reinforced thick part (the side surface is substantially hanging without creating a constriction part as in the conventional case).
.

This method greatly simplifies the machining of the tightening screw 16 that is set up almost immediately and is inserted through the reinforced thick walled portion 12a', and the tightening screw hole 16 is installed in a conventional bent overlapped portion. Unlike conventional screws, the screws are drilled into the thickness of the material themselves, so the tightening strength of the screws is significantly improved.

go up

Note that the above-mentioned joint processing includes, for example, sintering and spoon-shaped processing of the ball receiving portion 11', and that the inner surface of the steering shaft insertion cylindrical portion 15 is processed as a post-processing, such as serration processing. is the same as the conventional method.

According to this processing method, the punching process as in the conventional method and the processing process of performing several 180° bending processes on the punched material to form reinforcing curved parts are completely eliminated, and the corresponding process is as simple as described above. A cold forging process is sufficient, and the material yield deterioration and cost increase associated with punching are eliminated.

This processing method eliminates the cracks that occur mainly when processing conventional reinforcing curved parts, significantly improves the connection strength of the steering shaft, and is evaluated as a solution that eliminates safety concerns.

As described above, forming a part of the inner wall of the steering shaft insertion cylindrical part 15 with the reinforcing thick part 12a' is helpful in improving the strength.

The present invention includes a U-shaped joint for other shafts of a vehicle and a method for processing the same.

[Brief explanation of drawings]

Figure 1 is a perspective view showing the general structure of a conventional steering joint in a vehicle, and Figures 2A and B. Figures C and D show the processing method for a U-shaped joint in a conventional steering joint.
The figures will be explained using cross-sectional views. Fig. 3 is a perspective view of the same U-shaped joint showing an embodiment of the present invention, Fig. 4 is a perspective view showing the unit material before processing, and Fig. 5 is a processing of the U-shaped joint obtained by implementing the present invention. A perspective view showing the plate; FIGS. 6A, B, and C are cross-sectional views illustrating the method of manufacturing a U-shaped joint according to the present invention; FIG. 7 is a diagram showing the processing of a U-shaped joint obtained according to the present invention FIG. 3 is a cross-sectional view of the plate. 10...Unit material made of steel plate, 11...
...Ball receiving plate part, 12...Joint processing plate part, 12a...Thick wall part, 12b...Thin wall part, 12c...Slope surface , α...Warp, 1
2a'... Thick reinforcement part, 15... Cylindrical part for inserting the steering shaft, 16... Tightening screw hole.

Claims (1)

[Claims] 1 U for connecting shafts such as vehicle steering shafts
The U-shaped joint has a pair of ball receiving parts extending integrally from one side of the U-shaped joint, and the left and right inner wall surfaces of the opening of the U-shaped joint face inward to have equal thickness. A tightening screw is provided, in which a reinforcing thick part is formed, the inner bottom surface of the reinforcing thick part and the inner surface of the U-shaped joint part form a cylindrical part for shaft insertion, and the tightening screw passes through both of the reinforcing thick parts. This is a processing method for a U-shaped joint in a steering joint, etc., in which a hole is formed, in which a steel plate with the necessary thickness for reinforcement is prepared as a material, and a ball receiving plate part is formed into the material by cold forging. At the same time, a thick wall portion is formed at both ends of one side of the joint plate portion, and a thin wall portion is formed between the thick wall portions by the above-mentioned forging, and from the thin wall U.
The U-shaped joint part and the ball receiving part are formed by bending, and reinforcing thick parts are formed at both ends of the U-shaped joint part, with the thick parts thickened inwardly. None, the forging pressure during the above-mentioned forging process is applied intensively to the thin-walled portion without restricting the thick-walled portion, and the application of the forging pressure promotes an increase in the thickness of the thick-walled portion. In addition, during the forging process of the thick and thin parts, the thick part is curved upward toward the side where the thick part is used, and at the same time, an inclined surface is formed in the continuous part of the thick and thin parts. A steering joint for a vehicle, characterized in that the above-mentioned U-shaped bending process is then carried out over several degrees from the above-mentioned thin-walled part to form the above-mentioned U-shaped joint part, ball receiving part, and reinforcing thick-walled part. Processing method of U-shaped joint in etc.