JPH0577886B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a ball joint,
In particular, the present invention relates to a method of manufacturing a ball joint that has an oil reservoir at the bottom of the spherical receiving part of the holder and can achieve smooth rotational movement and rocking movement.

[Prior Art] Conventionally, a method for manufacturing this type of ball joint is, for example, to set a sphere like a core in a mold of a holder, and to cast a die-cast molten alloy into this mold to make a ball joint. A holder with a sphere held inside is cast, and the sphere held in this holder and the rod body are welded by friction welding to form a rod with a ball held in the holder, and the sphere of the holder is There is a known method of manufacturing a ball joint by applying an external force between the receiving part and the spherical part of a ball-equipped rod to form a gap between them (Japanese Patent Publication No. 11002/1983). In this method, a sphere with a smooth surface and high sphericity can be used as the sphere constituting the sphere part of the rod with a ball, and the sphere receiving part of the holder is cast using this sphere as a core. It is known that it has the feature of being able to form a hard chill layer on the inner surface of the spherical receiving part.

[Problems to be Solved by the Invention] However, in the above conventional manufacturing method, there is no means for fixing the sphere used as a core in the holder casting mold so that it does not move. When die-casting molten alloy is poured into a mold, the sphere may move with the flow of the die-casting molten alloy, causing the sphere to shift its position and resulting in defective products. Casting the alloy required skill, and this also caused problems in terms of productivity. Furthermore, in the conventional manufacturing method, when welding the sphere and the rod body to form a rod with a ball, the two are brought into contact and rotated relative to each other under pressure to utilize the frictional heat generated at that time. They are joined by so-called friction welding, and the pressure applied between the sphere and the rod body is high during friction welding, and even if a sphere with a high degree of vacuum is used, Due to the high pressure and high frictional heat that acts on the sphere, the degree of vacuum will go out of whack, and when it becomes a rod with a ball, the degree of vacuum in the sphere has already decreased, which makes it difficult to use a sphere with a high degree of vacuum. In addition to this, it becomes necessary to provide a gap as large as the difference between the maximum diameter and the minimum diameter of the spherical part between the spherical part and the spherical receiving part of the holder that rotatably and swingably accommodates the spherical part. In order to create this large gap, it becomes necessary to apply an unnecessarily large external force between the spherical part and the spherical receiving part, which may accidentally damage the spherical receiving part, or when multiple parts are combined to form a link mechanism, etc. However, there is a problem in that a large gap accumulates between the spherical part and the spherical receiving part, resulting in a significant drop in accuracy in force transmission, etc. Furthermore, due to the deviation in the degree of vacuum of the spherical part, the spherical part and the spherical receiving part If the gap between the holder and the receiving part becomes larger than necessary, a large impact load will be applied between the two during use, and the spherical receiving part of the cast holder may be damaged. In addition, when forming a rod with a ball by friction welding, tempering treatment after welding must be performed in a separate process, and if left for a long time before tempering treatment after welding, so-called placement cracks will occur in the welded part. Therefore, a tempering treatment must be performed as soon as possible after welding, and a deburring process for the welded portion is also required, which limits the manufacturing process.

Therefore, an object of the present invention was created in view of this point of view, and the sphericity of the spherical part of the rod with a ball is extremely high. It is possible to reduce the gap between the parts, eliminate rattling between them, and make their rotation and rocking movements smoother, as well as prevent large impact loads from acting between them during use The object of the present invention is to provide a method by which a ball joint can be manufactured without any problems.

[Means for Solving the Problems] That is, the present invention sets a highly spherical sphere constituting a ball-attached rod in a holder casting mold as a core of a sphere receiver, and also sets this sphere on one side. It is fixed between the mold member and the sphere support part of the other mold member, die-cast molten alloy is cast into this holder casting mold to cast a holder in which the sphere is held in the sphere receiver part, and then , the spherical surface of the sphere held in this holder is butted against the flat surface formed at the end of the rod body, and an electrode for applying welding current is connected to both of these members to perform butt projection welding. The above two members are joined to form a rod with a ball with the spherical part held in the holder, and after applying current again to the welded part with the electrode connected as it is and tempering the welded part, the spherical receiving part of the holder is An external force is applied between the spherical part of the rod with a ball to form a gap therebetween, and a lid member is attached to the opening formed by the spherical support part of the mold member to close the oil reservoir. This is a method for manufacturing a ball joint characterized by forming a ball joint.

In the method of the present invention, the method for manufacturing a ball joint equipped with a ball-attached rod having a high degree of vacuum in the sphere part basically involves using a sphere with a high degree of vacuum, and creating a space between the sphere and the rod body. Welding may be carried out by butt projection welding, and this welding produces less welding burr, and there is no need for cutting or the like to remove this welding burr. In addition, by welding the flat surface formed at the end of the rod body against the spherical surface of the sphere, the spherical surface functions as a projection part, so there is no need to perform any special processing on both parts. , projection welding can be easily carried out simply by applying electricity between these members.

Further, after welding the sphere and the rod body by this butt projection welding, the welded portion can be easily tempered by applying current again with the electrodes still connected. As a result, for example, in high-carbon steel, if left unused for a long time after welding, cracks occur in the welded part, so-called "recess cracks". can be completely prevented.

Furthermore, in the present invention, a sphere support part is provided on one of the mold members in order to securely fix the sphere during holder casting, so that the cast holder is equipped with an opening corresponding to the sphere support part. However, this opening functions as a welding jig and electrode insertion port to pressurize the rod body and sphere during butt projection welding between the rod body and the sphere, and also serves as an electrode insertion port by fixing the lid member. Functions as an oil reservoir when using a joint.

[Function] According to the method of the present invention, the sphere used as the core is fixed by the sphere support provided on one mold member and the other mold member, so that the die casting molten alloy can be cast. The sphere will not shift its position.

In addition, by joining the rod body and the highly vacuumed sphere using butt projection welding, which uses the spherical surface of the sphere as the projection part,
A rod with a ball that has a high degree of vacuum can be easily manufactured, and since the ball receiving part of the holder is cast using this highly vacuumed sphere as a core, the gap between the ball receiving part and the sphere can be reduced. The size can be reduced to the minimum necessary size, and the structure can be such that large impact loads do not occur during use.

[Example] Hereinafter, the method for manufacturing a ball joint of the present invention will be specifically described based on Examples shown in the accompanying drawings.

1 to 3, a first embodiment of a ball joint manufactured by the method of the invention is shown. This ball joint has a holder 1 equipped with a spherical receiving part 2 on one end side and a connecting part 3 on the other end side, and maintains the minimum necessary clearance between the spherical receiving part 2 of the holder 1 on one end side. A rod 4 with a ball is provided with a spherical part 5 with a high degree of vacuum that is held so as to be rotatable and swingable, and a connecting part 6 is provided on the other end side.
and a connecting portion 6 between the ball receiving portion 2 and the ball-attached rod 4.
It accommodates lubricant such as grease to be supplied between the spherical part 5 and the spherical receiving part 2, and also prevents dust, dirt, etc. The shape of the holder 1 is such that the spherical receiving part 2 opens in a direction substantially perpendicular to the connecting part 3, and the spherical receiving part 2 An oil reservoir 9 sealed by a lid member 8 is formed at the bottom of the oil reservoir 9 .

In this embodiment, the lid member 8 that forms the oil reservoir 9 is made of a thin disc-shaped plate, and is formed at the bottom of the spherical receiving part 2 during casting of the holder 1 to form the oil reservoir 9. It is fixed by caulking a protrusion 10 provided on the periphery of the opening. and,
The connecting portion 3 of the holder 1 is formed with a female thread 3a, and the connecting portion 6 of the ball-equipped rod 4 is formed with a male thread 6a. A hexagonal tool engaging portion 11 is formed with which a tool is engaged to rotate the balled rod 4 when it is connected to another member, and a tool is similarly engaged with one end of the connecting portion 3 of the holder 1. A substantially rectangular tool engaging portion 12 that fits is formed. Further, the sealing member 7 has one end 7a locked in the tool engaging portion 11, and the other end 7a.
b is engaged with the opening edge of the sphere receiving part 2 to form a lubricant pocket 13 therebetween, and the opening edge of the sphere receiving part 2 of the holder 1 is provided with a lubricant pocket 13. A edging surface 14 is formed to restrict the swing angle of the balled rod 4 that is held and swings.

Next, regarding the manufacturing method of the ball joint according to this embodiment, first, the holder 1 is cast using the sphere 4a as a core, and then the sphere 4a held in the cast holder 1 and the rod body 4b are butted. This is done by a method of manufacturing the rod 4 with a ball by projection welding.

That is, as shown in FIG. 4, a sphere 4a with a high degree of vacuum is set in a holder casting mold 20 divided into upper and lower parts as a core of the sphere receiving part 2 when casting the holder 1. A sphere 4a used as a core is attached to an upper mold member 21 and a lower mold member 2.
The core 2 is inserted and fixed between the spherical support part 23 provided on the holder 1, and is further provided with a core 2 for forming a female thread 3a in the part constituting the connecting part 3 of the holder 1.
4 is set, a die-cast molten alloy is cast into the holder casting mold 20 to cast the holder 1. Holder 1 cast in this way
As shown in FIGS. 5 to 7, a sphere 4 which becomes the sphere part 5 of the ball-attached rod 4 is attached to the sphere receiving part 2.
a is cast and held, and the spherical receiving part 2
An opening 9a serving as an oil reservoir 9 is formed on the bottom side of the opening 9a, and a protrusion 10 that is caulked when fixing the lid member 8 is formed on the periphery of the opening edge. In this embodiment, in this state, the female thread 3a and the tool engaging portion 12 of the connecting portion 3 of the holder 1 are
It has been processed.

After casting the holder 1 in which the spheres 4a are cast in this way, as shown in FIG.
The spherical surface of the rod body 4b and the flat surface formed at the end of the rod body 4b are brought into contact with each other.
Electrodes for applying welding current are connected to a and 4b, respectively, and a predetermined pressure F is applied while a predetermined welding current is applied for a predetermined welding time to butt the rod main body 4b and the sphere 4a for projecting. They are joined by welding, and then current is applied again while the electrodes are connected, and the welded portion is tempered to form a holder 1 in which the spherical portion 5 of the balled rod 4 is cast into the spherical receiving portion 2. At this time, it is preferable to insert a jig (not shown) for receiving pressure F into the opening 9a of the holder 1 to support the sphere 4a.
If the jig is brought into contact with the sphere 4a, this jig can be used as an electrode on the sphere 4a side.

Next, a light impact is applied between the thus formed spherical receiving part 2 of the holder 1 and the spherical part 5 of the ball-equipped rod 4 by, for example, lightly tapping the outer periphery of the spherical receiving part 2. , an external force is applied to the rod 4 with a ball by applying a tensile force or the like to form a minute gap between them, and the spherical part 5 of the rod 4 with a ball is pressed against the spherical receiving part 2 of the holder 1. After filling an opening 9a formed at the bottom of the spherical receiving part 2 of the holder 1 with a lubricant such as grease, the opening 9 is made to be rotatable and/or swingable.
By fitting the lid member 8 into the opening edge of a and caulking the protruding strip 10 formed around the periphery of the opening 9a,
This lid member 8 is fixed to the opening edge of the opening 9a to form the oil reservoir 9.

Furthermore, as shown in FIG.
A seal member 7 is attached between the tool engaging portion 11 provided at the base, and a lubricant pocket 13 formed by the seal member 7 is filled with a lubricant such as grease.

[Effects of the Invention] According to the method of the present invention, the sphere is securely fixed in the mold during casting, and the sphere does not shift its position when pouring the die-cast molten alloy, thereby reducing the occurrence of defective products. Others that can prevent
We manufacture durable ball joints that can reduce the gap between the ball receiver and the ball part to the minimum necessary size, and are unlikely to receive large impact loads between them during use. can do.

In addition, since the rod body and the highly vacuumed sphere held in the holder are joined by butt extension welding using the spherical surface of the sphere as the projection part, rods with balls that have a high degree of spherical vacuum can be manufactured easily in a short time. There is no need for a cutting process to remove welding burrs, and further,
Tempering treatment can also be easily performed following the welding process by simply applying a recurrent current, and productivity is significantly improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of a ball joint that can be manufactured by the method of the present invention, FIG. 2 is a left side view of FIG. 1, FIG. 3 is a right side view of FIG. 1, and FIG. The figure is an explanatory diagram showing a method of casting a holder using a sphere as a core, Figure 5 is a partial sectional view of the holder into which the sphere is cast, Figure 6 is a right side view of Figure 5, and Figure 7 is a Figure 5 is a plan view, Figure 8 is an explanatory diagram showing how to join the sphere cast in the holder and the rod body by projection welding, and Figure 9 is formed by projection welding as shown in Figure 8. FIG. 3 is an explanatory cross-sectional view showing the ball-equipped rod and holder. Explanation of symbols, 1...Holder, 2...Ball receiver,
3... Connecting part, 4... Rod with ball, 5... Sphere part, 6... Connecting part, 7... Seal member, 8... Lid member, 9... Oil reservoir part, 4a... Sphere, 4b ……
Rod body, 20...Holder casting mold, 21,
22... Mold member, 23... Sphere support part.

Claims (1)

[Claims] 1. A highly spherical sphere constituting a ball-attached rod is set in a holder casting mold as a core of a sphere receiving part, and this sphere is connected to the sphere supporting part of one mold member and the other mold member. A die-cast molten alloy is cast into this holder casting mold to cast a holder in which the sphere is held in the sphere receiver, and then the spherical surface of the sphere held in this holder and the end of the rod body are At the same time, electrodes for applying welding current are connected to these two members, and the two members are joined by butt projection welding, and the spherical part is held in the holder. A rod with a ball is formed, and the welded part is tempered by applying current again with the electrodes connected as they are, and then an external force is applied between the ball receiving part of the holder and the ball part of the rod with a ball. A method for manufacturing a ball joint, comprising: forming a gap therebetween, and attaching a lid member to the opening formed by the spherical support portion of the mold member to form an oil reservoir.