JP6815266B2 - Ball joint manufacturing method and ball joint - Google Patents

Description

The present invention relates to a method for manufacturing a ball joint having a ball-side member provided with a ball portion and a ball joint.

Conventionally, a ball joint that connects a tire side and a vehicle body side is used in a suspension device or a steering device of a vehicle such as an automobile. A ball joint generally includes a ball stud which is a ball side member, a housing, and a ball sheet made of, for example, a synthetic resin, which is a bearing sheet, and the ball portion at the end of the ball stud can be rotated by the ball sheet. It is housed in the housing while being held in the housing. The housing is usually formed by forging using steel or aluminum, and after molding, an external pressure is applied to the housing to plastically deform it, thereby applying a preload to the ball part of the ball stud or forming a gap to slide the housing. Make it movable (see, for example, Patent Document 1).

Japanese Patent No. 4319070 (pages 4-6, FIG. 4-5)

In recent years, resin-based housings have been required for the purpose of reducing the weight and cost of ball joints. For example, in order to make the housing resin, it is the easiest as a manufacturing method to injection-mold the housing with the ball portion or the ball portion and the ball sheet as the core.

However, when the housing is injection-molded in this way, the housing made of synthetic resin cannot be plastically deformed by applying an external pressure after molding. Therefore, as described in Patent Document 1, a preload may be applied after molding or a preload may be applied. It is difficult to form a gap. Such a problem arises not only for ball joints for steering devices and suspension devices, or ball joints for vehicles, but also for ball joints used at arbitrary locations.

The present invention has been made in view of these points, and an object of the present invention is to provide a method for manufacturing a ball joint and a ball joint capable of appropriately applying a preload to a ball side member while the housing is made of synthetic resin. To do.

The method for manufacturing a ball joint according to claim 1 is a method for manufacturing a ball joint including a ball-side member including a ball portion, a bearing sheet, an urging member, a receiving member, and a housing. A holding step in which the ball portion is rotatably held by the bearing sheet, and an attachment in which the urging member and the receiving member are attached with the urging member interposed between the bearing sheet and the receiving member. a step, while maintaining the state of pressing the bearing seat by the urging member, said housing, said bearing seat holding the ball portion, and the biasing member, and at least a portion of said receiving member, It is provided with a molding step of molding with a synthetic resin so as to accommodate the bearing.

The method for manufacturing a ball joint according to claim 2 is the method for manufacturing a ball joint according to claim 1, wherein a pressing member is used in the molding step, and the receiving member is pressed toward the bearing seat side by the pressing member. The state in which the bearing sheet is pressed by the urging member is maintained.

The ball joint manufacturing method according to claim 3 includes a covering step for covering a hole of a housing formed at a position corresponding to a pressing member by a molding step in the ball joint manufacturing method according to claim 2. is there.

The ball joint according to claim 4 includes a ball-side member provided with a ball portion, a bearing sheet for rotatably holding the ball portion, and an urging member for urging the ball-side member via the bearing sheet. When the receiving member for receiving the reaction force of the urging of the ball-side member by the urging member, and the bearing seat holding the ball portion, and the biasing member, and at least a portion of the receiving member, the It is provided with a housing made of synthetic resin for accommodating.

According to the method for manufacturing a ball joint according to claim 1, a state in which the bearing sheet is pressed by an urging member interposed between the bearing sheet that rotatably holds the ball portion of the ball side member and the receiving member. while maintaining the bearing seat holding the ball portion, a biasing member, receiving by forming the housing from a synthetic resin so as to accommodate at least a portion of the member, while the housing is made of synthetic resin, with Preload can be appropriately applied to the ball-side member by urging the force member.

According to the ball joint manufacturing method according to claim 2, in addition to the effect of the ball joint manufacturing method according to claim 1, a pressing member is used in the molding step to push the receiving member toward the bearing seat side. By pressing the bearing sheet, the bearing sheet can be easily maintained in a pressed state by the urging member.

According to the ball joint manufacturing method according to claim 3, in addition to the effect of the ball joint manufacturing method according to claim 2, the hole portion of the housing formed at a position corresponding to the pressing member during the molding process is covered. Therefore, it is possible to easily maintain the state in which the bearing sheet is pressed by the urging member by the pressing member, and to suppress foreign matter from entering the inside of the housing from the hole.

According to the ball joint according to claim 4, while the housing is made of synthetic resin, preload can be appropriately applied to the ball side member by the urging of the urging member interposed between the bearing sheet and the receiving member. ..

It is sectional drawing which shows the ball joint of one Embodiment of this invention. It is explanatory drawing which shows the holding process of the manufacturing method of the ball joint as above. It is explanatory drawing which shows the mounting process of the manufacturing method of the ball joint as above. It is explanatory drawing which shows the molding process of the manufacturing method of the ball joint as above. It is explanatory drawing which shows the covering process of the manufacturing method of the ball joint as above.

Hereinafter, the configuration of one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 11 denotes a ball joint, which is used, for example, in an automobile steering device or a suspension device. In the present embodiment, the ball joint 11 will be described by taking the tie rod end of the steering device as an example. The ball joint 11 includes a ball stud 14 which is a ball side member, a ball seat 15 which is a bearing sheet, a spring 16 which is an urging member, a receiving member 17, and a housing 18. Further, the ball joint 11 may include a covering member 19. Further, the ball joint 11 may be provided with a dust cover (not shown). Hereinafter, the lower side in FIG. 1 will be described as a lower side which is one end side, and the upper side will be described as an upper side which is the other end side. Further, the longitudinal direction of the ball stud 14 in the upright state (that is, the vertical direction in FIG. 1) is referred to as an axial direction, and the direction orthogonal to this axial direction is referred to as an axial direct direction.

The ball stud 14 is also called a ball shank or the like, and is made of steel, for example. The ball stud 14 integrally includes a spherical ball portion 21 and a shaft-shaped stud portion 22 connected to the ball portion 21.

A part of the outer peripheral surface of the ball portion 21 is slidably (rotated) held by the ball sheet 15.

The stud portion 22 is a portion to which a load is applied by being connected to an external connected member (not shown) such as a knuckle arm. The stud portion 22 projects outward from the housing 18. The stud portion 22 may be provided with a flange portion that comes into contact with the connected member, for example.

The ball sheet 15 holds the ball portion 21 of the ball stud 14 so as to be slidable (rotatable). That is, the ball sheet 15 includes a spherical sliding surface 25 that includes the ball portion 21. The ball sheet 15 may have, for example, a bag shape in which one end (upper end) is opened and the other end (lower end) is closed, or a cylindrical shape in which both ends are opened. That is, the ball sheet 15 has an opening 27 at least at one end. From this opening 27, a part of the ball portion 21 (the portion of the ball portion 21 on the stud portion 22 side) is exposed to the outside of the ball sheet 15, and the stud portion 22 is projected to the outside of the ball sheet 15. .. The ball sheet 15 is housed in the housing 18 while holding the ball portion 21. Further, on the other end side of the ball sheet 15 opposite to the opening 27, an urging contact portion 28 with which the spring 16 contacts is formed. Further, a protruding portion 29 for positioning the spring 16 may be formed on the other end side of the ball sheet 15. The ball sheet 15 is made of synthetic resin. For example, the ball sheet 15 is made of a synthetic resin that can withstand the molding temperature of the housing 18 described later.

The urging contact portion 28 is a portion where one end side of the spring 16 is contacted. The urging contact portion 28 is formed in a planar shape having a plane direction along the axial direction, for example.

The protruding portion 29 protrudes to the other end side of the ball sheet 15 at the central portion of the urging contact portion 28. The protruding portion 29 is a regulating portion that regulates lateral displacement of one end side of the spring 16 that abuts on the urging contact portion 28.

The spring 16 is a preload applying member that applies a predetermined preload (preload) to the ball stud 14 by urging the ball stud 14 via the ball seat 15. As the spring 16, for example, a compression coil spring is used in the present embodiment, but a leaf spring or the like may be used, or a relatively soft synthetic resin such as a block shape, which is not a spring, may be used. One end of the spring 16 is in contact with one end of the ball sheet 15, specifically, the urging contact portion 28, and the other end is in contact with the receiving member 17. That is, the spring 16 is arranged so as to exert an urging force on the ball seat 15 and the receiving member 17 in a direction in which the ball seat 15 and the receiving member 17 are separated from each other. For example, in the present embodiment, the spring 16 is formed so as to gradually increase in diameter from the receiving member 17 side which is the other end side (lower end side) to the ball sheet 15 side which is one end side (upper end side). Has been done.

The receiving member 17 receives the reaction force of the urging of the spring 16 against the ball stud 14. That is, the receiving member 17 is in contact with the other end (lower end) of the spring 16 and supports the spring 16. In the present embodiment, the receiving member 17 is formed, for example, in a bottomed cylindrical shape. More specifically, in the present embodiment, the receiving member 17 is formed by having an accommodating portion 31 having a predetermined depth inside. That is, the receiving member 17 is formed in a flat dish shape having a depth (axial direction) dimension smaller than the diameter dimension. Therefore, the receiving member 17 includes a receiving bottom portion 32 and a rising portion 33 raised from the outer edge portion of the receiving bottom portion 32. The receiving member 17 may be formed of a metal material such as aluminum or iron, or may be formed of a synthetic resin.

The accommodating portion 31 is a space portion for accommodating the spring 16. The opening on one end of the accommodating portion 31 is closed when one end (upper end) side of the receiving member 17 (raising portion 33) contacts the other end side (biased contact portion 28) of the ball sheet 15. ing. The depth dimension DP of the accommodating portion 31 is set to be smaller than the length L of the spring 16 in the no-load state (DP <L, FIG. 3). Therefore, the spring 16 is accommodated in the accommodating portion 31 in a state of being compressed in the axial direction.

The housing 18 is also called a socket or the like, and is formed of, for example, a synthetic resin. In the present embodiment, as the material of the housing 18, for example, a synthetic resin such as a fiber reinforced plastic (for example, CFRP), a fluororesin (for example, PTFE), and a super engineering plastic (for example, PEEK) is used. Thus, the housing 18 is made of non-metal and is formed, for example, by insert injection molding. Further, the housing 18 is formed in a bottomed cylindrical shape. That is, the housing 18 includes a bottom portion 34 and a wall portion 35 raised from the outer edge portion of the bottom portion 34. Then, in the housing 18, the inner chamber 36 is internally partitioned by the bottom portion 34 and the wall portion 35, and the upper end portion, which is the end portion of the wall portion 35 opposite to the bottom portion 34, is inside. It has an opening 37 that communicates with the room 36. Further, the housing 18 may have a hole 38 formed at the bottom thereof so as to communicate with the inner chamber 36. Further, the housing 18 may be formed with a cover fixing groove 39 as a cover mounting portion for fixing the dust cover. Then, the housing 18 may be integrally formed with a housing connecting portion such as a screwed portion into which a tie rod is screwed so as to project in the axial direction.

The inner chamber 36 is a housing accommodating portion for accommodating the ball seat 15, the spring 16, and the receiving member 17 that rotatably hold the ball portion 21. The inner chamber 36 is formed so as to gradually reduce its diameter toward the upper side, which is the opening 37 side, and the ball seat 15, the spring 16, and the receiving member 17 housed in the inner chamber 36 are opened. It is configured so that it does not come out of part 37.

The opening 37 is a portion where the stud portion 22 of the ball stud 14 in which the ball portion 21 is housed in the inner chamber 36 projects to the outside of the housing 18. The opening 37 faces the opening 27 of the ball sheet 15 and communicates with the opening 27 to be formed on one end side (upper end side) of the housing 18.

The hole 38 is formed when the housing 18 is molded, as will be described later. The hole 38 communicates with the inner chamber 36, and is formed in, for example, the central portion of the bottom 34. The hole 38 is formed smaller than the opening 37.

The cover fixing groove 39 is formed in an annular groove shape along the circumferential direction on the outer periphery of one end side (upper end side) of the housing 18, for example.

The covering member 19 is a member that covers the hole 38. In the present embodiment, the covering member 19 is also called a seal plug and is a member that closes the hole 38. As the covering member 19, for example, a closing member formed separately from the housing 18 by elastic rubber or an elastomer may be fitted into the hole 38, or the hole 38 may be closed by welding synthetic resin or the like. It may be formed in. The covering member 19 is not an essential configuration.

The dust cover, also called a dust seal or boot, covers the opening 37 of the housing 18 regardless of the swing of the ball stud 14 and prevents moisture and dust from entering the inside of the housing 18 or the ball sheet 15. It is a thing. This dust cover is formed in a substantially cylindrical shape by, for example, synthetic resin, the upper end side is fixed to the outer peripheral surface of the stud portion 22 of the ball stud 14, and the lower end side is fitted into the cover fixing groove 39 of the housing 18, and the lower end side thereof. It is tightened and fixed by a ring-shaped fixing member attached (or embedded) to the outer peripheral surface.

Next, a method for manufacturing the ball joint 11 according to the above embodiment will be described.

First, as shown in FIG. 2, the ball portion 21 of the ball stud 14 is rotatably held by the ball sheet 15 (sliding surface 25) (holding step), and the first intermediate 41 (FIG. 3) is held. Form. For the ball stud 14, for example, the ball portion 21 and the stud portion 22 may be integrally molded from a metal material such as a rod, or the ball portion 21 and the stud portion 22 may be integrally molded by welding or the like. It may be transformed into. Further, the ball sheet 15 may be attached to the ball portion 21 in a preformed state, or may be attached to the ball portion 21 by injection molding or the like. For example, in the case of a ball sheet 15 that is attached to the ball portion 21 in a preformed state, a so-called molded type in which the sliding surface 25 is formed in a spherical shape in advance along the outer peripheral surface of the ball portion 21 is used. It is preferably used. Further, it is preferable that a lubricant is held between the ball portion 21 and the sliding surface 25 of the ball sheet 15. After applying this lubricant to the outer peripheral surface or the sliding surface 25 of the ball portion 21, the ball portion 21 may be held by the ball sheet 15, or after the ball portion 21 is held by the ball sheet 15. It may be injected between the ball portion 21 and the sliding surface 25 in a later step.

Next, as shown in FIG. 3, the spring 16 and the receiving member 17 are placed between the ball sheet 15 (the urging contact portion 28) and the receiving member 17 (the receiving bottom portion 32) with respect to the first intermediate body 41. The second intermediate 42 (FIG. 4) is formed by mounting (mounting step) with the spring 16 interposed therebetween.

Further, as shown in FIG. 4, a ball sheet of the second intermediate 42 is used in the cavity C of the molding die D by using the molding die (for example, a mold) D and the pressing member (for example, a pin which is a supporting member) P. With the 15, spring 16 and receiving member 17 set and the ball stud 14 held by the molding die D, the receiving member 17 (receiving bottom portion 32) is directed toward the ball sheet 15 side (biased contact portion 28). By pressing with the pressing member P inserted into the cavity C, the state in which the ball sheet 15 is pressed by the spring 16 is maintained, in other words, one end side (upper end side) of the receiving member 17 (raising portion 33) is the ball sheet. The ball sheet 15 and the spring 16 holding the ball portion 21 are solidified by injecting a molten material into the cavity C from a gate (not shown) while maintaining the state of being in close contact with the 15 side (the urging contact portion 28). And, at least a part of the receiving member 17, in the present embodiment, the housing 18 is molded (molding step) with the entire receiving member 17 as a core to form the third intermediate body 43 (FIG. 5). In this state, at least a part of the ball seat 15, the spring 16, and the receiving member 17 holding the ball portion 21, and the entire receiving member 17 in the present embodiment are housed in the housing 18, and the housing part 31 is in a compressed state. A spring 16 located at provides an axial preload to the ball stud 14 via the ball seat 15. Further, in the housing 18, a hole 38 (FIG. 5) is formed at a position of a pressing member P inserted into the cavity C.

Then, the hole 38 of the housing 18 formed at the position corresponding to the pressing member P (FIG. 4) is covered with the covering member 19 with respect to the third intermediate body 43 shown in FIG. 5 that has been removed from the molding die D. Along with (coating process), the dust cover is attached between the cover fixing groove 39 and the stud portion 22 of the ball stud 14 (finishing process) to complete the ball joint 11 (FIG. 1).

As described above, according to the above embodiment, the ball sheet 15 is pressed by the spring 16 interposed between the ball sheet 15 that rotatably holds the ball portion 21 of the ball stud 14 and the receiving member 17. while maintaining the state, the ball seat 15 holding the ball portion 21, a spring 16, and at least a portion of the receiving member 17, by molding the housing 18 of synthetic resin so as to accommodate a housing 18 Although it is made of synthetic resin, the preload can be appropriately applied to the ball stud 14 by the urging of the spring 16 interposed between the ball sheet 15 and the receiving member 17.

Therefore, in the case of a metal housing, a preload is applied to the ball stud 14 or a gap is formed between the ball portion 21 and the sliding surface 25 by plastically deforming the ball stud 14 by applying an external pressure after molding. On the other hand, even if the housing 18 is made of synthetic resin, which is not easy to do, the preload can be appropriately applied by molding the housing 18.

By making the housing 18 made of synthetic resin, the weight and cost of the ball joint 11 can be reduced, and the preload can be appropriately applied to the ball stud 14, so that the ball portion 21 and the ball sheet can be appropriately applied. An appropriate friction torque with the 15 (sliding surface 25) can be set to ensure the durability and reliability of the ball joint 11.

Further, in the molding process of the manufacturing method of the ball joint 11, the pressing member P is used to press the receiving member 17 toward the ball sheet 15 side by the pressing member P, so that the ball sheet 15 is pressed by the spring 16. Easy to maintain.

Further, by covering the hole 38 of the housing 18 formed at the position corresponding to the pressing member P during the molding process of the manufacturing method of the ball joint 11, it is easy to press the ball sheet 15 by the spring 16 by the pressing member P. It is possible to prevent foreign matter from entering the inside of the housing 18 from the hole 38 while maintaining the value.

In the above embodiment, when the ball sheet 15 is kept pressed by the spring 16 in the molding step, for example, the bottom 34 of the receiving member 17 is abutted against the cavity C of the molding die D. By receiving the spring 16 from the ball stud 14 side and pressing it against the member 17, the ball sheet 15 can be maintained in a state of being pressed by the spring 16 by the reaction force. In this case, the housing 18 can also be molded so as not to accommodate the bottom 34 of the receiving member 17. Therefore, the housing 18 does not have to be molded to accommodate the entire receiving member 17, but may be molded to accommodate at least a part of the receiving member 17.

Further, the ball joint 11 can be used not only for the steering device but also for any other purpose.

The present invention is suitably used for, for example, a suspension device for a vehicle such as an automobile, a steering device, or the like.

11 ball joint
14 Ball stud, which is a member on the ball side
15 Ball seat, which is a bearing seat
16 Spring that is an urging member
17 Receiving member
18 housing
21 Ball part
38 Hole P Pressing member

Claims (4)

A method for manufacturing a ball joint including a ball-side member provided with a ball portion, a bearing sheet, an urging member, a receiving member, and a housing.
A holding step of rotatably holding the ball portion with the bearing sheet, and
An attachment step of attaching the urging member and the receiving member with the urging member interposed between the bearing sheet and the receiving member.
While maintaining the state of pressing the bearing seat by the urging member, the housing, for accommodating said bearing seat holding the ball portion, and the biasing member, and at least a portion of the receiving member A method for manufacturing a ball joint, which comprises a molding step of molding with a synthetic resin. The first aspect of claim 1, wherein in the molding step, a pressing member is used to press the receiving member toward the bearing sheet side by the pressing member to maintain the state in which the bearing sheet is pressed by the urging member. How to manufacture ball joints. The method for manufacturing a ball joint according to claim 2, further comprising a coating step of covering a hole of a housing formed at a position corresponding to a pressing member by a molding step. A ball-side member with a ball part and
A bearing sheet that rotatably holds the ball portion and
An urging member that urges the ball-side member via the bearing sheet,
A receiving member that receives the reaction force of the urging of the ball-side member by the urging member, and
Ball joint for said bearing seat holding the ball portion, and the biasing member, and at least a portion of said receiving member, characterized by comprising a synthetic resin housing for accommodating the.

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