JPS6026820A - Shell material of tripod type uniform speed joint and producing method - Google Patents

Abstract

PURPOSE:To form a groove and a projection excellently as well as to form a cup part and a shaft part forming the shell member in a body with the same material, by providing a ring groove, a projection and a hole in the cup part. CONSTITUTION:An axial shaft part 2 and a cylindrical cup part 3 forming a shell member are formed in a body by using respective materials of high-carbon steel that can be subjected to induction hardening. A screw part 29 and a spline part 28 are provided, on the shaft part 2 and subjected to induction hardening. On the other hand, the forced fit part 36 of a dust cover and a seal part 37 are provided on the outside diameter face on the shaft part 2 side of the cup part 3. A ring groove 33 to fix a tripod axis is formed on the inside diameter face of a cup part 3 and also a projection 32 is formed at the center of the ring groove 33. A small diameter hole 34 that is smaller than the outside diameter of the projection 32 is formed on the outside diameter face of the cup part 3 in the position corresponding to the projection 32. The cup part 3 and the shaft part 2 are formed in a body by these processes.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a 1-
The present invention relates to an outer shell part 4 of a ribo-1 type constant velocity joint and a method for manufacturing the same.

FIG. 1 shows the outer shell of a conventional constant velocity joint of the 1- to 1-point type. 11. Outer shell of the tripod-type equi-connected joint not shown in FIG. 1. J. A shaft-shaped cup 1 part 2 and a cylindrical cup part 3 are formed separately, and these two parts 2 and 3 are joined at the joint surface 11 and integrated.

However, the outer shell member 1 formed by joining the shaft in this manner has the following problems.

(i) First, friction welding is generally used as a joining method to integrate the shaft portion 2 and the cup portion 3;
When this friction welding is incorporated into a process in a mass production line, it is quite difficult to maintain the welding quality. Normally, a few pieces every 10 are sampled from the production line and subjected to destructive inspection to ensure welding quality.

Therefore, there is a problem that special processed products, equipment, and people are required for destructive inspection, and it is difficult to completely guarantee the quality of welding on the production line by sampling several welds per day. It was necessary to visually monitor the appearance of welding spots.

(11) Also, as shown in Fig. 1, weld burrs 5 appear on the inner diameter side of the cup portion 3 due to friction welding, but this weld burr 5
For example, if there is a concern about interference with the structure inside the cup portion 3, it is necessary to remove it, and it is generally removed by cutting.

However, when removing the welding edge by this cutting, the welding edge 5 is heated and rapidly cooled during friction welding and becomes extremely hard, so the number of processing per piece of cutting tool in the edge cutting process on the production line is small, resulting in high cost. There is a problem with high

(iii) Note that if there is no interference with the structure inside the cup part 3, the welding edge 5 may be left as is and the process of trimming the edge may be omitted. After being installed on a vehicle, etc., when vibration etc. are applied, a part of the welding tension 5 may fall off and cause damage to the joint.
There is a problem that there is a problem that the lifespan of joins 1 to 1 is reduced due to M2r inclusion.

(1v) Fig. 2 shows a schematic diagram of the chuck and its surroundings in the friction welding process.As can be understood from this figure, in the past, the cup part 3 was centered at the outer diameter part 3a, and the end face 3b was used to receive the thrust. On the other hand, the shaft part 2 is connected to the seal part 2.
Centering is performed at point a, and thrust receiving is performed at end surface 2b. However, as is well known, since the joint surface 4 of friction welding becomes high temperature, the thrust receiving jig 2c of the shaft 71 to section 2 is very susceptible to wear due to the influence of the high temperature, and as a result, it frequently wears out. There is a problem in that the thrust receiving jig 2c must be replaced.

In addition, as a countermeasure to this problem, 01 which is less susceptible to heat
It is also possible to perform thrust receiving on the 11th surface 2d or 2c, but these 6m surfaces 2d and 2e are the joint surface 4.
Since the position is not directly below the thrust direction, there is a problem that the ring portion 2I may be bent by the thrust force of friction welding.

The above-mentioned conventional problems are caused by the fact that the outer shell member 1 is divided into the inner shaft part 2 and the cup part 3. The reason for this is explained below.

FIG. 3 shows a cross-sectional view of the tripod-type constant velocity joint in the assembled and extended state. A tripod shaft 31 is disposed on the inner diameter part of the cup portion 3, and in order to fix this tripod shaft 31, the cup A ring-shaped groove 33 and a protrusion 32 are formed at the center of the ring-shaped groove 33 on the inner diameter surface of the portion 3. Since the three tripod shafts 31 are arranged at 12° intervals, the ring-shaped grooves 33 and the protrusions 32 are similarly formed at three equal intervals on the circumference of the inner diameter surface.

The conventional method of forming the ring-shaped ti 33 and the protrusion 32 is schematically shown in FIG.
After guiding and inserting the cup part 3 into the outer mold 41 and determining the longitudinal reference with the lower mold 42, the punch 44 fixed to the punch boulder 43 is pushed outward in the half direction to form a ring shape by plastic deformation. The groove 33 and the protrusion 32 are formed.In forming the ring-shaped groove 33 and the protrusion 32, low carbon 1-2 is selected as the material for the cup portion 3 from the viewpoint of formability.
It is considered preferable to use 1.

On the other hand, when the shaft portion 2 of the outer shell member 1 is mounted on a vehicle, the shaft portion 2 is connected to a hub at its spline portion and transmits driving force to the wheels.

Therefore, since strength is required for the shirts 1 and 2, high carbon steel is generally used as the material and induction hardened.

In this way, the required characteristics of the shaft portion 2 and the force and protrusion portion 3 of the outer shell member 1 are different, and due to the difference in required characteristics, the materials used are also different. were constructed separately and joined together.

Therefore, the first object of the present invention is to improve the method of forming the ring-shaped groove and protrusion formed on the inner diameter surface of the cup part, thereby making it possible to use the same material as the shaft part as the material of the cup part. In this case, the cup part and the shaft part are integrally formed.

A second object of the present invention is to enable the ring-shaped grooves and protrusions to be formed satisfactorily even when high carbon steel is used as the material for the cup portion.

The first object of the present invention described above is that, according to the present invention, the cylindrical cup portion forming the outer shell member and the axial shaft portion are integrally formed of a high carbon steel material. The inner surface of the cylindrical cup part has a ring-shaped groove for retaining and fixing the tripod shaft, and a protrusion is formed in the center of this ring-shaped groove, and the protrusion corresponds to the position where the protrusion is formed. The structure of the outer shell Fits +, l of a tripod type constant velocity joint is characterized in that a hole with a smaller diameter than the outer diameter of the protrusion is formed on the outer diameter surface of the cylindrical cup part. J.
is achieved.

A second object of the present invention is that, according to the present invention, a cylindrical cup portion and an axial shaft portion are integrally formed from high carbon steel material by appropriate processing means such as hot forging. ,after that,
An internal molding punch is pressed radially outward from the inner diameter surface of the cylindrical cup portion to form a ring-shaped groove that engages and fixes the tripod shaft on the inner diameter surface of this cup portion, and a central portion of this ring-shaped groove. In addition to plastically deforming the protrusion, during this processing,
From the outer surface of the cylindrical cup portion corresponding to the processing position by the inner forming punch, press radially outward with an outer punch to form a protrusion on the inner diameter surface of the cup portion. This is achieved by a method for manufacturing an outer shell member of a tripod type constant velocity joint, characterized in that the protrusion formed on the inner diameter surface is reliably formed by plastically deforming a hole having a diameter smaller than the outer diameter dimension.

In addition, in the present invention, high carbon steel is used as the material of the outer shell member that integrally forms the top part and the cup part of the shirt 1.
If low carbon steel is used, not only will the outer shell itself be heavy and large, but the hub of the mating part will also be large, increasing the weight of the vehicle, which is not a good idea.

By having the above-described configuration, the present invention can obtain the following effects.

(a) Since the shaft portion and cup portion of the outer shell member are integrally formed, it is possible to eliminate the friction welding process in the production line, improving productivity and reducing manufacturing costs. can.

(b) Also, as friction welding is eliminated, it is no longer necessary to take out several welds from the production line for inspection each day and conduct destructive inspections to ensure welding quality, and we also monitor the appearance of welding cracks. There's no need to do that.

(c) In addition, various problems conventionally caused by friction welding can be solved all at once.

(d) Even if the force/knob part is made of high carbon steel, which is the same material as the shaft part, when forming ring-shaped grooves and protrusions on the inner diameter surface of the cup part, the outer punch should be removed from the outer diameter surface of the force/knob part. The protrusion can be reliably formed by pressing the hole to form a hole in the outer diameter surface.

Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 5 shows an embodiment of the outer shell member 1 of the present invention.

A shaft portion 2 and a cup portion 3 constituting the outer shell member 1 are integrally formed. The shaft portion 2 is formed into an axial shape, and the cup portion 3 is formed into a cylindrical shape. The shaft 71 to portion 2 and the cup portion 3 are made of high-carbon steel that can be induction hardened.

The shaft portion 2 has a threaded portion 29 and a spline portion 28, and is induction hardened.

A dust cover press-fit portion 36 and a seal portion 37 are provided on the outer diameter surface of the cup portion 3 on the shaft portion 2 side. In addition,
In the conventional outer shell part +A1 shown in FIG. 1, a thrust receiving part 38 is provided, but since friction welding is not performed in the present invention, this is unnecessary, and the shape of the outer diameter surface is changed along the inner diameter surface. It has the advantage of being lightweight compared to conventional products.

As in the conventional case, a ring-shaped groove 33 for fixing the tripod shaft and a protrusion 32 at the center thereof are formed on the inner diameter surface of the cup part 3. A hole 34 having a smaller diameter than the outer diameter of the protrusion 32 is formed in the outer diameter surface of the cup portion 3 corresponding to the position where the ring-shaped groove 33 and the protrusion 32 are formed.

Next, an embodiment of the method for manufacturing the outer shell member 1 not shown in FIG. 5 mentioned above will be described.

First, the shaft 71~part 2 and the cup part 3 were integrated by hot forging using high carbon steel that can be induction hardened]■
Make a shape.

After hot forging, the shaft portion 2 and the cup portion 3 are machined to a predetermined shape, and then the threaded portion 29 and the spline portion 2 are cut out.
8 is formed by rolling.

Next, the seal portion 37 and the spline portion 28 are induction hardened to increase the strength of the portions.

Finally, use the inner forming punch and outer punch to
A ring-shaped groove 33 and a protrusion 32 are formed on the inner diameter surface, and a hole 34 is formed on the outer diameter surface.

FIG. 6 shows a schematic diagram of forming the ring-shaped groove 33 and the protrusion 32 in this last step.If the outer shell member 1 is inserted and explained in detail based on FIG. It is installed on the lower mold 62.

In this state, the inner forming punch held by the punch boulder 64 is pressed and moved radially outward from the inner diameter side to form the ring-shaped groove 33 and the protrusion 32 on the inner diameter surface.

Meanwhile, at the same time, the outer punch 67 held by the outer die 66 is pressed and moved radially inward from the outer diameter side to form a hole 34 on the outer diameter surface and a protrusion 32 formed on the inner surface. We make sure that the height is sufficient.

As a result, even when using a high carbon steel material that generally has poor formability, the protrusion 32 can be formed in a precise manner.

In FIG. 6, the outer diameter d2 of the projection 68 of the outer punch 67 is smaller than the inner diameter d of the inner forming punch 63.

FIG. 7 shows the inner diameter dimension d of the inner forming punch 63 which is not shown in FIG.
, =7.5+nm, and the height t of the protrusion 32 (not shown in FIG. 8) is shown in the case of molding under each of the following conditions (1) to (2). Note that this graph shows that the higher the protrusion height, the better the moldability.

Condition I: The conventional product shown in FIG. 1 was molded using the conventional molding method shown in FIG. The material of the cup part 3 in this case is 5H.
P28, it is a so-called low carbon steel with good formability.

Condition (1): The product according to the present invention shown in FIG. 5 was molded using the conventional molding method shown in FIG. The material in this case is induction hardenable high carbon steel (S'45C).

Condition (1): The product according to the present invention shown in FIG. 5 was manufactured by the manufacturing method according to the example of the present invention shown in FIG.
The material is high carbon f1i'1 (345G) that can be induction hardened.
), and the outer diameter dimension d2 of the protrusion 68 of the outer punch 67 =
4.5mm.

Condition (2): Basically the same as the above condition (2), except that the outer dimension of the protrusion 68 of the outer punch 67 is 12-6°3.

The test results shown in Figure 7 show that even when using high carbon steel, which normally has poor formability, the outer punch 6 as shown in Figure 6
It has been proven that by providing No. 7, the present invention can ensure moldability that is second to none compared to the prior art.

Furthermore, it can be seen that if the outer diameter dimension d2 of the outer punch 67 is set to 5 mm or more, a height t comparable to that of conventional low carbon steel (SHP28) can be secured even in high carbon steel (345C). .

Although specific embodiments illustrating the present invention have been described above, the present invention is not limited to such embodiments.
Various other embodiments are possible within the scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a partial 1JJi side view showing the outer shell member of the Tribo-1-type constant velocity injector 1- from iJL. FIG. 2 is a schematic diagram of the chuck and its surroundings in a conventional friction welding process. FIG. 3 is a sectional view showing the assembled state of a conventional general-purpose tripod type constant velocity joint 1-. FIG. 4 is a schematic diagram showing a conventional molding method. FIG. 5 is a partial sectional view showing an embodiment of the outer shell member of the 1-report type constant velocity joint of the present invention. FIG. 6 is a schematic diagram showing an embodiment of the molding method of the present invention. FIG. 7 is a graph showing the test results. FIG. 8 is a sectional view showing the height of the protrusion. Explanation of symbols 1 ---- Outer shell member 2 ------- Shaft part 3 ------- Cup part 31 ------- Report shaft 32 ------- Protrusion 33 ---- Ring Shape groove 34 --- Hole 63 --- One-way forming punch 67 --- One-way punch Figure 1 ] Figure 2 S Figure 6 64

Claims (1)

[Claims] 1. The cylindrical cup portion forming the outer shell member and the axial shaft portion are integrally formed of high carbon steel material, and one thread surface of the cylindrical cup portion has a 1-A ring-shaped groove for holding and fixing the report shaft, and a protrusion is formed in the center of this ring-shaped groove, and on the outer diameter surface of the cylindrical cup portion corresponding to the position where the protrusion is formed, The outer shell of the 1-report type constant velocity joint is characterized by having a hole smaller in diameter than the outer diameter of the protrusion. The shaft portion is integrally formed by an appropriate processing method such as hot forging, and then an inner forming punch is pressed radially outward from the inner diameter surface of the cylindrical cup portion to form the first and second cup portions. A ring-shaped groove for engaging and fixing the tripod shaft and a protrusion in the center of the ring-shaped groove are plastically deformed on the inner (fleece surface), and the machining position with the inner forming punch is Press radially inward from the outer diameter surface of the cylindrical cup portion corresponding to A method for manufacturing an outer shell member of an I-report type constant velocity joint 1-, characterized in that the protrusion formed on the inner surface (i) is reliably formed by plastically deforming the hole (i).