JPH0754125B2 - Manufacturing method of ball joint having oil groove on inner peripheral surface of ball receiving sliding member - Google Patents

Description

The present invention relates to a method for manufacturing a ball joint in which a ball-receptive sliding member, particularly a ball-receptive sliding member formed by filling a molten material, is formed, and at the same time, an oil groove is directly formed in the sliding member. .

The conventional ball joint has a portion a that holds the ball 101.
It is customary to use a split mold as shown in FIG.

Therefore, the metal part that holds the ball 101 is divided into two parts, the upper part metal 102 and the lower part metal 103.
The recesses 104 and 105 that are approximately the same in diameter as the
The ball 101 is fitted into the concave portion 105 of 03, and then, the upper metal 102 is inserted and caulked, or the both are fixed by an appropriate means such as a bolt nut, so that the assembly work is troublesome.

In addition, the recess that holds the ball is cut to the same size as the diameter of the ball, and after inserting the ball into the recess, the clearance ring made by another product is fitted and assembled, so that the outer circumference of the ball matches the inner circumference of the clearance ring. It is difficult to get a high precision ball joint.

A ball joint is also known, in which a plastic molten material is injected into a cavity formed between a ball and a holder (socket) to form a sleeve in order to omit machining and the like. Due to
The inner circumference of the formed sleeve holds the ball firmly, and the outer circumference is in close contact with the inner circumference of the socket, so there is no gap, and the ball joint always has a preload, which prevents smooth rotation. Have.

Further, since it is impossible to form an oil groove in the sleeve, there is a defect that the coefficient of friction becomes large and the friction increases.

In order to improve the above-mentioned drawbacks, the present inventor firstly, as shown in FIGS. 2 to 3, firstly, a bolt with a ball 1 having a ball at its tip.
Is integrally manufactured, and a hole having a diameter larger than the diameter of the ball is used to form a concave portion larger than the diameter of the ball in the holding portion 3 of the holder 2. Further, the ball holding portion of the holder 2 is formed. 3. A pouring hole 4 and an air vent hole 5 are formed on the side wall of 3, and then the bolt 1 with a ball and the holder 2 are set in a mold 6 to form a cavity between the ball, the holder and the holding portion. Then, a die-cast molten alloy is cast between the cavities to form a sleeve. After that, after the sleeve 7 is cooled and solidified, the ball-bearing bolt 1 and the holder 2 are taken out from the mold 6 and then physically or mechanically. By applying an external force to form a gap between the outer peripheral surface of the ball and the inner peripheral surface of the sleeve 7, a highly accurate ball joint can be provided.

However, the ball joint only forms a gap between the cast sleeve and the ball, and it is impossible to form an oil groove for grease guide on the inner circumference of the sleeve.

A technical object of the present invention is to provide a highly accurate method of manufacturing a ball joint by filling a cavity formed between a ball and a holder with a molten material and forming an oil groove at the same time.

It is also intended to improve the performance of the ball receiving sliding member by non-cutting injection molding or vulcanization and to reduce the cost by mass production.

The constitution of the present invention for solving the above technical problems, that is, the technical means is as follows.

A bolt with a ball having a ball at its tip is manufactured, and separately from this, a holder and a rod portion forming a penetrating ball holding portion are integrally formed, and the diameter of the ball holding portion is set to The diameter is larger than the diameter, and a pouring hole and an air vent hole are further formed in the side wall of the ball holding portion, and the integrally formed holder and rod portion are set in a mold, and then, At least one of the balls of the ball-attached bolt is inserted into the ball holding portion from above, and protrudes upward from the bottom portion in the holding portion.
The ball-bearing bolt is set in the mold by supporting the ball with one or more projecting pieces to form a cavity between the ball and the ball holding part, and then the cavity is inserted into the cavity through the pouring hole. Axial oil whose one end is opened in one direction by the ball receiving sliding member and the projecting piece between the ball and the holder holding part by cooling and solidifying the molten metal material after cooling and solidifying after solidifying A groove is formed, and thereafter, an external force is applied to the demolded bolt with ball and the holder to form a gap between the outer peripheral surface of the ball and the inner peripheral surface of the ball receiving member, and the ball. The inner peripheral surface of the ball receiving sliding member, which is configured by attaching a grease cover to the upper and lower parts of the holding portion via a sealing material and putting grease into the grease cover. It is in the process of ball joint with oil grooves.

The effects achieved by the above technical means are as follows.

Since the mold having the protruding piece formed between the ball and the ball holding portion or the core having the protruding piece is set in the mold, the filled ball receiving sliding member contacts the outer peripheral surface of the ball. At the same time when the peripheral surface is formed, the protruding piece directly forms an axial oil groove having one end opening in one direction.

Since the oil groove is located in the grease reservoir, the grease rises in accordance with the movement of the ball bolt or the rod, and the lubricating effect on the sliding surface of the sliding member can be enhanced.

Also, since a split groove (oil groove) of approximately ten characters is formed on the lower side of the ball receiving sliding member, an external force (striking) is evenly applied to the outer peripheral surface of the holder after casting injection molding or vulcanization molding. At this time, the strain of the ball receiving sliding member can escape through the split groove, and the gap can be easily formed.

An embodiment of the present invention will be described below with reference to FIGS. 4 to 7.

The ball 11 is integrally formed with the bolt 10 by a means such as turning or pressure welding from a material having high mechanical strength, for example, steel material, or is fixed to form a bolt with a ball.

Next, the ball holding portion 13 of the holder 12 is provided with a through hole 14 having a diameter slightly larger than the diameter of the tip ball 11 of the ball-attached bolt and a step portion 15 at the opening end thereof. 16 is a plurality of protruding pieces 17,1
In the movable mold in which 7 ... Is formed, the thickness t of the projecting piece 17 is an oil groove within a range that does not affect the strength of the ball receiving sliding member 18.
Corresponding to 20, the width is located slightly below the equator of the tip ball 11 in consideration of draft and strength.

A pouring hole 19 and a gas vent hole 21 are formed in the side wall of the ball holding portion 13 of the holder 12. In the drawing, 22 is a fixed die, 24 is a gate, 25 is a runner, 26 is a gas reservoir, 27 is a grease cover, 30 is a ring, 31 Hagrease, and 32 is a groove for a grease cover.

Next, a method for manufacturing the ball joint will be described.

First, in the first step, the ball 11 is fixed to the tip of the bolt 10 by means such as friction welding using a material having excellent toughness, wear resistance and mechanical strength, or one ball 11 and one bolt 10 are used. It is formed by turning from the steel material.

Next, as the second step, from steel materials with excellent mechanical strength,
The holder 12 is manufactured integrally, and then the ball
A through hole (14) having a diameter larger than that of the ball (11) and a stepped portion (15) are formed at an opening end of the through hole (14) where the ball (11) is fitted.

Next, the bolt with balls is vertically inserted into the holder 12, and the tip ball 11 is supported by the movable mold 16 having a plurality of projecting pieces 17 from below, and then the upper mold 22 is assembled.

As described above, the ball 11 is positioned in the center of the holder 12, and at the same time, the top of the ball 11 is supported by the curved surfaces of the plurality of projecting pieces 17, 17.

One of the sliding-requiring members, for example, a die-cast molten alloy is cast into the cavity 33 between the ball 11 and the through hole of the holder 12,
After cooling and solidification, the movable mold with the protruding piece formed integrally is pulled out, and the bolt with ball and holder 12 are removed from the upper mold 22.
When taken out, an oil groove 20 having a width C is formed.

After that, by tapping the outer peripheral portion of the holding portion of the holder, the ball receiving metal 18 extends axially and circumferentially,
The ball 11 and the ball receiving metal 18 extend in the axial direction and the circumferential direction, and a slight gap is formed between the ball 11 and the ball receiving metal 18.

Next, the grease cover 29 is attached to the upper portion of the ball holding portion via the ring 30, and the grease cover 27 is fixed to the lower portion by crimping one end 34 inward.

Since the ball receiving metal of the ball joint manufactured by the method of the present invention has the same inner peripheral surface as the outer peripheral surface of the ball formed by means such as mechanical turning, polishing or casting, friction resistance with the ball is almost eliminated. There is no need for a turning process to form the oil groove in the ball receiving metal because it smoothly rotates and at the same time, a plurality of oil grooves (split grooves) in the ball receiving metal are automatically formed along the ball spherical surface. do not do.

Further, it has been made possible by this method that it was conventionally impossible to form an oil groove in a cast ball receiving metal.

Although the above example describes a die-cast alloy, which is one of the sliding members, it is not limited to the die-cast alloy and injection molding or vulcanization of engineering rings such as polyimide, polyacetal and polycarbonate, plastics or synthetic rubbers. It can be molded.

FIGS. 10 to 12 show another embodiment of manufacturing the ball joint of the method of the present invention. Instead of integrally forming the protruding piece as shown in FIG. 8 with the movable mold, As shown in FIG. 10, a core 23 having a protruding piece 17 is formed.

Next, the core 23 is set in the lower mold 16 (see FIG. 11).
Then, the cavity is filled with the molten material to form the ball receiving / sliding member.

Next, after the ball receiving and sliding member is cooled and solidified, the core 23 is removed to open the axial oil groove 20 with one end open in one direction.
To form.

The same parts are designated by the same reference numerals as those in FIGS. 4 to 9, and the description thereof will be omitted.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a conventional split type ball joint, FIG. 2 is a vertical sectional view showing a manufacturing method of a conventional ball joint, FIG. 3 is a plan view of the ball joint, and FIG. FIG. 4 is a vertical cross-sectional view showing a state in which a ball receiving metal cavity is formed by a projecting piece between a ball-bearing bolt set in a mold and a ball holding portion. FIG. 6 is a sectional view of the ball receiving metal, FIG. 7 is a sectional view taken along line BB of FIG. 5, and FIG. 8 is a partial sectional perspective view of a lower mold integrally formed with a plurality of projecting pieces. FIG. 10 is a sectional view of a ball joint, FIG. 10 is a partial sectional perspective view showing another embodiment of the method of the present invention, and FIG. 11 is a sectional view showing a state in which the core of FIG. 10 is assembled in a mold. , FIG. 12 is a sectional view taken along the line AA in FIG. 11: Ball, 12: Holder 13: Ball holding part, 16: Movable mold 17: Projecting piece, 18: Sliding member 19: Pouring hole, 20: Oil groove 21: Gas vent hole, 22: Fixed mold , 23: Nakako

Claims (1)

[Claims] (A) A ball-mounted bolt having a ball at its tip is manufactured, and separately from this, a holder and a rod portion constituting a penetrating ball holding portion are integrally formed, and the ball holding portion is formed. The diameter of the holding portion is set to be larger than the diameter of the ball. (B) Further, a pouring hole and an air bleeding hole are formed in the side wall of the ball holding portion, (C) and the integrally formed portion. The holder and the rod portion are set in the mold, and then the ball of the ball-attached bolt is inserted into the ball holding portion from above, and at least one or more protruding upward from the bottom portion in the holding portion. By supporting the ball with the projecting piece, the bolt with ball is set in the mold to form a cavity between the ball and the ball holding portion, and (D) then, from the pouring hole into the cavity. Molten metal After the material has been cast, it is cooled and solidified, and after solidification, it is removed from the mold to form a ball receiving slide member and an axial oil groove whose one end opens in one direction by the projecting piece. (E) After that, a gap is formed between the outer peripheral surface of the ball and the inner peripheral surface of the ball receiving sliding member by applying an external force to the removed bolt with ball and the holder. F) A grease cover is attached to the upper and lower parts of the ball holding part via a sealing material, and (G) and grease is put into the grease cover. How to make a ball joint.