JP2020159541A - Ball joint and manufacturing method therefor - Google Patents

Abstract

To provide a ball joint capable of improving a holding effect for a ball sheet in a housing and also capable of being manufactured efficiently.SOLUTION: A ball joint 10 comprises: a ball stud 12 having a ball part 20; a ball sheet 13 that rotatably holds the ball part 20; and a cylindrical housing 14 that internally receives the ball sheet 13 holding the ball part 20. The housing 14 has: an opening part 34 formed at one end part in an axial direction; a bent part 36 bent from a predetermined position in the axial direction to the one end part where the opening part 34 is located; and a rough surface machined part 42 formed on an inner peripheral surface 33 from a predetermined position to the one end where the opening part 34 is located, and bitten into the outer surface of the ball sheet 13.SELECTED DRAWING: Figure 1

Description

The present invention relates to a ball joint including a tubular receiving side member that internally receives a holding member holding the ball portion, and a method for manufacturing the same.

Conventionally, there are ball joints used in automobile steering devices and the like. This ball joint includes a ball stud which is a ball side member, a cylindrical housing which is a receiving side member, and a cylindrical ball sheet made of synthetic resin which is a holding member, and the ball portion at the end of the ball stud. Is housed inside the housing in a state of being rotatably held by a ball sheet. In such a ball joint, an uneven portion that bites into the outer peripheral surface of the ball sheet is provided near the opening edge of the housing on the inner peripheral surface of the housing so that the ball sheet does not fall off from the housing when a load is repeatedly applied to the ball stud. Some are formed (see, for example, Patent Document 1).

Jikkenhei No. 5-42741 (page 4, Fig. 1)

The uneven portion described in Patent Document 1 is only located near the opening edge of the housing, and additional processing or configuration for improving the holding effect of the ball sheet is required. Such a problem also occurs in other than the ball joint used for the steering device for automobiles and the like.

The present invention has been made in view of such a point, and an object of the present invention is to provide a ball joint capable of being efficiently manufactured and a method for manufacturing the same while improving the holding effect of the holding member on the receiving side member.

The ball joint according to claim 1 is a tubular receiving side that internally receives a ball-side member having a ball portion, a holding member that rotatably holds the ball portion, and the holding member that holds the ball portion. The receiving side member includes an opening formed at one end in the axial direction, a bent portion bent from a predetermined position in the axial direction to one end where the opening is located, and an inner peripheral surface. It has a roughened surface processed portion formed from the predetermined position to one end where the opening is located and bites into the outer surface of the holding member.

The ball joint according to claim 2 is the ball joint according to claim 1, wherein the surface roughness Ra of the roughened surface processed portion is 15 to 45.

The ball joint according to claim 3 is the ball joint according to claim 1 or 2, wherein the holding member is formed of a member softer than the receiving side member.

The method for manufacturing a ball joint according to claim 4 is a tubular shape that internally receives a ball-side member having a ball portion, a holding member that rotatably holds the ball portion, and the holding member that holds the ball portion. A method of manufacturing a ball joint including the receiving side member, wherein the receiving side member is formed into a tubular shape having an opening at one end, and the inner peripheral surface of the receiving side member is axially oriented. The rough surface processing step of physically scraping from a predetermined position to one end where the opening is located to form a rough surface processing portion, and the holding member holding the ball portion are received from the opening. The insertion step of inserting into the inside of the side member and the portion of the receiving side member from the predetermined position to one end where the opening is located are bent toward the central axis side to hold the roughened surface processed portion of the holding member. It is provided with a bending process of biting into the outer surface.

The method for manufacturing a ball joint according to claim 5 is a tubular shape that internally receives a ball-side member having a ball portion, a holding member that rotatably holds the ball portion, and the holding member that holds the ball portion. It is a method of manufacturing a ball joint including a receiving side member of the above method, in which an opening is provided at one end and an opening is provided at the other end, and the peripheral edge of the opening is provided at one end from a predetermined position in the axial direction. A forming step of forming a tubular receiving-side member main body having a bent portion that shrinks toward each other, and the inner peripheral surface of the receiving-side member main body is physically extended to one end where the opening is located at the bent portion. The rough surface processing portion is held by inserting the holding member holding the ball portion into the inside of the receiving side member main body through the opening and the rough surface processing step of forming the rough surface processed portion. It includes an insertion step of biting into the outer surface of the member and a closing step of closing the opening of the receiving side member main body with a closing member to form the receiving side member.

The ball joint manufacturing method according to claim 6 is the ball joint manufacturing method according to claim 4 or 5, wherein in the rough surface processing step, the inner peripheral surface of the receiving side member has a surface roughness Ra of 15 to 45. This is a process of physically shaving so as to form a roughened surface.

The ball joint manufacturing method according to claim 7 is the ball joint manufacturing method according to any one of claims 4 to 6, wherein the holding member is formed of a member softer than the receiving side member.

According to the ball joint according to claim 1, a rough surface machined portion is formed on the inner peripheral surface of the receiving side member from a predetermined position to one end where the opening is located, and the roughened surface is formed from a predetermined position in the axial direction of the receiving side member. By forming a bent portion over one end where the opening is located, the entire region of the inner peripheral surface of the receiving side member that reliably contacts the outer surface of the holding member can be used as a roughened surface. Since the rough surface processed portion can be formed by physically scraping the inner peripheral surface while improving the holding effect of the holding member on the receiving side member by biting the surface processed portion into the outer surface of the holding member, for example, chemical treatment or the like. Compared with the case of forming a film with, it can be manufactured more efficiently.

According to the ball joint according to the second aspect, in addition to the effect of the ball joint according to the first aspect, by setting the surface roughness Ra of the rough surface processed portion to 15 to 45, the ball joint can be surely bitten into the outer surface of the holding member. At the same time, it is possible to suppress a decrease in the contact area between the inner peripheral surface of the receiving side member and the outer surface of the holding member, and suppress an increase in the load per unit area.

According to the ball joint according to claim 3, in addition to the effect of the ball joint according to claim 1 or 2, the holding member is formed of a member softer than the receiving side member to hold the rough surface processed portion. It can be surely bitten into the outer surface of the.

According to the method for manufacturing a ball joint according to claim 4, in the rough surface processing step, a rough surface processed portion is formed on the inner peripheral surface of the receiving side member from a predetermined position to one end where the opening is located. In the bending step, by bending the bent portion from a predetermined position in the axial direction of the receiving side member to one end where the opening is located, the inner peripheral surface of the receiving side member is reliably in contact with the outer surface of the holding member. The entire region can be used as a rough surface processed portion, and the rough surface processed portion can be made to bite into the outer surface of the holding member to improve the holding effect of the holding member on the receiving side member, while the rough surface processed portion has an inner peripheral surface. Since it is formed by physically scraping it, it can be manufactured more efficiently than when a film is formed by, for example, chemical treatment.

According to the method for manufacturing a ball joint according to claim 5, in the rough surface processing step, the rough surface processed portion is formed from the inner peripheral surface of the bent portion of the receiving side member body to one end where the opening is located. Therefore, of the inner peripheral surfaces of the receiving side member, the entire inner peripheral surface of the bent portion that reliably contacts the outer surface of the holding member can be used as the roughened surface processed portion, and the roughened surface processed portion bites into the outer surface of the holding member. While improving the holding effect of the holding member on the receiving side member, the roughened surface is formed by physically scraping the inner peripheral surface, so that it is compared with the case where a film is formed by, for example, chemical treatment. It can be manufactured efficiently.

According to the ball joint manufacturing method according to claim 6, in addition to the effect of the ball joint manufacturing method according to claim 4 or 5, in the rough surface processing step, the surface roughness Ra of the rough surface processed portion is 15 to 15. By setting the value to 45, it is possible to suppress a decrease in the contact area between the inner peripheral surface of the receiving side member and the outer surface of the holding member while surely biting into the outer surface of the holding member, and suppress an increase in the load load per unit area. ..

According to the ball joint manufacturing method according to claim 7, in addition to the effect of the ball joint manufacturing method according to any one of claims 4 to 6, the holding member is formed of a member softer than the receiving side member. Therefore, the rough surface processed portion can be surely bitten into the outer surface of the holding member.

It is sectional drawing which shows the ball joint of 1st Embodiment of this invention. It is sectional drawing which shows the receiving side member of the ball joint as above. (a) is a cross-sectional view showing the formation process of the same ball joint manufacturing method, (b) is a cross-sectional view showing the rough surface processing process of the same ball joint manufacturing method, and (c) is the insertion of the same ball joint manufacturing method. A cross-sectional view showing the process, (d) is a cross-sectional view showing a bending process of the same method for manufacturing a ball joint. It is sectional drawing which shows the ball joint of the 2nd Embodiment of this invention. (a) is a cross-sectional view showing the formation process of the same ball joint manufacturing method, (b) is a cross-sectional view showing the rough surface processing process of the same ball joint manufacturing method, and (c) is the insertion of the same ball joint manufacturing method. A cross-sectional view showing the process, (d) is a cross-sectional view showing the closing process of the same ball joint manufacturing method.

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

In FIG. 1, 10 indicates a ball joint. The ball joint 10 is used, for example, in an automobile suspension device or a steering device. The ball joint 10 of the present embodiment will be described by taking an inner ball joint (IBJ) used in the steering device as an example.

The ball joint 10 includes a ball stud 12 which is a ball side member, a ball sheet 13 which is a holding member (bearing sheet), and a housing 14 which is a receiving side member. Further, although not shown, the ball joint 10 may be provided with a dust cover.

The ball stud 12 is provided with a spherical ball portion 20 at one end, and a shaft-shaped stud portion 21 is connected from the ball portion 20 to the other end. The ball stud 12 is made of steel or the like.

A part of the outer peripheral surface of the ball portion 20 is slidably or rotatably held by the ball sheet 13. In the ball portion 20 of the present embodiment, a predetermined region in the axial direction including at least the equator position E is held by the ball sheet 13 on the outer peripheral surface. The equator position E refers to the position of the outer peripheral surface of the ball portion 20 having the largest diameter dimension when viewed in a cross section intersecting or orthogonal to the axial direction, which is the direction of one end and the other end of the ball stud 12.

The stud portion 21 is a portion connected to an external connected member such as a tie rod end (not shown) to which a load is applied. The stud portion 21 may be integrally formed with the ball portion 20, or may be formed separately from the ball portion 20 and then integrated with the ball portion 20 by welding or the like.

The ball sheet 13 is formed in a cylindrical shape. The ball sheet 13 integrally includes a seat main body 23 which is a cylindrical holding member main body and a load receiving portion 24 which is connected to the end of the seat main body 23. The ball sheet 13 is provided with one sheet opening 25, which is one holding member opening, at least at one end. One of the seat openings 25 is located at one end of the seat body 23 or the ball seat 13. Further, the ball sheet 13 of the present embodiment is provided with the other sheet opening 26 which is the other holding member opening at the other end. The other seat opening 26 is formed so as to penetrate the load receiving portion 24. Further, the inner peripheral surface of the ball sheet 13 is a sliding contact surface with the ball portion 20. Grooves, recesses, protrusions and the like may be formed on the inner peripheral surface of the ball sheet 13 as needed. The ball sheet 13 is made of a synthetic resin or the like having excellent wear resistance and a high elastic modulus. That is, the ball sheet 13 is formed of a member that is softer than the housing 14.

The seat body 23 is preformed in a straight cylinder shape having a constant or substantially constant inner diameter, and in a state where the ball sheet 13 is housed inside the housing 14, a load receiver is received according to the deformation of the housing 14. It is deformed so as to be gradually reduced in diameter along the outer peripheral surface of the ball portion 20 toward one end portion on the side away from the portion 24. That is, the seat body portion 23 is housed in the housing 14, and the equator position E is set at a predetermined position in the axial direction, that is, a position intersecting the plane including the equator position E of the ball portion 20 in the present embodiment. A portion extending from one end to one end, which is the peripheral edge of the seat opening 25, is a seat bent portion 28 which is a holding member bent portion bent so as to be gradually reduced in diameter toward the one end.

The load receiving portion 24 is formed so as to be gradually reduced in diameter toward the direction away from the seat main body portion 23, that is, toward the other end of the ball seat 13. The outer peripheral surface of the load receiving portion 24 is formed in a conical shape.

One of the seat openings 25 is formed in advance to have a diameter larger than that of the ball portion 20, and when the ball seat 13 is housed in the housing 14, the seat bending portion 28 has a diameter smaller than that of the ball portion 20. The diameter is reduced to.

The housing 14 is also called a socket or the like, and is formed in a bottomed cylindrical shape. That is, the housing 14 integrally has a housing main body 30 which is a cylindrical receiving side member main body and a closing portion 31 which closes an end portion of the housing main body 30. Inside the housing 14, an inner chamber 32 for accommodating the ball sheet 13 is formed by the housing main body portion 30 and the closing portion 31, and the inner chamber 32 is surrounded by the inner peripheral surface 33 of the housing 14. There is. Further, an opening 34 for communicating the inner chamber 32 with the outside of the housing 14 is formed at one end of the housing 14 which is an end opposite to the closing portion 31 in the axial direction. Further, the housing 14 may be formed with a cover fixing groove as a cover mounting portion for fixing the dust cover. The housing 14 is made of metal, for example, formed by forging or casting in the present embodiment.

As shown in FIG. 2, the housing main body 30 is formed in advance in a rectangular shape having a constant or substantially constant inner diameter, and as shown in FIG. 1, the ball sheet 13 is housed inside the housing 14. In this state, the bending point is a predetermined position in the axial direction, that is, a position intersecting the plane including the equator position E of the ball portion 20 in the present embodiment, and extends from this bending point to one end which is the peripheral edge of the opening 34. The portion is bent so as to be gradually reduced in diameter toward one end portion to form a bent portion 36. The bent portion 36 prevents the ball sheet 13 holding the ball portion 20 from coming off from the housing 14. Further, the inner chamber 32 is formed so as to be narrowed at the position of the bent portion 36. That is, at the position of the bent portion 36, the inner peripheral surface 33 of the housing 14 is gradually reduced in diameter toward one end portion. Further, the bent portion 36 is located at one end of the housing main body 30 or the housing 14, and is not formed at the other end. That is, the other end side of the housing main body 30 is a straight cylindrical non-bent portion 37. The non-bent portion 37 forms a portion extending from a position intersecting the plane including the equator position E of the ball portion 20 to the closed portion 31. At the position of the non-bent portion 37, the diameter dimension of the inner peripheral surface 33 of the housing 14 is constant or substantially constant.

The closing portion 31 is formed so as to be connected to the other end portion of the housing main body portion 30. The closing portion 31 is formed in a direction intersecting the axial direction of the housing main body 30, and closes the other end of the housing main body 30. The closing portion 31 is located at a position axially opposed to the ball portion 20 via the ball sheet 13, and is a portion of the housing 14 that receives the largest load from the ball stud 12 side. Further, a connecting portion 40 connected to an external connected portion such as a rack shaft may be formed outside the closing portion 31. In the present embodiment, the connecting portion 40 is formed in a male screw shape, for example. The connection portion 40 is not an essential configuration.

The inner chamber 32 is formed so as to be gradually reduced in diameter toward the other end of the housing 14 at a position corresponding to the closing portion 31.

The inner peripheral surface 33 is a portion that contacts or faces the outer peripheral surface of the ball sheet 13. A rough surface processed portion 42 and a non-rough surface processed portion 43 are formed on the inner peripheral surface 33.

The rough surface processed portion 42 is a portion formed by physically cutting the inner peripheral surface 33, contacting the outer peripheral surface of the ball sheet 13, and biting into the outer peripheral surface of the ball sheet 13. The roughened surface machined portion 42 is the entire portion extending from the non-roughened surface machined portion 43 to one end side of the inner peripheral surface 33 of the housing 14. The rough surface processing portion 42 is an inner peripheral surface 33 extending from a position intersecting a plane including the equator position E of the ball portion 20 in the housing main body portion 30, that is, a bending point of the bending portion 36 to one end where the opening 34 is located. It is a band-shaped area of. That is, the rough surface processed portion 42 is a region corresponding to the bent portion 36 on the inner peripheral surface 33 of the housing 14. That is, the rough surface processed portion 42 is the inner peripheral surface of the bent portion 36. Then, the rough surface processing portion 42 bites into the outer peripheral surface of the seat bending portion 28 of the ball sheet 13. The rough surface processed portion 42 is formed so that the surface roughness Ra is in the range of 15 to 45, preferably 20 to 30. In addition, in FIG. 1 and the like, the rough surface processing portion 42 is shown with emphasis on unevenness in order to clarify the explanation.

The non-roughened surface processed portion 43 is a portion having a smaller surface roughness Ra than the roughed surface processed portion 42. Further, the non-rough surface processing portion 43 is non-contact with the outer peripheral surface of the ball sheet 13 or lightly with respect to the outer peripheral surface of the ball sheet 13 when no load is applied to the ball stud 12 of the ball joint 10. Contact. The non-roughened surface machined portion 43 is the entire region extending from the roughened surface machined portion 42 to the other end side of the inner peripheral surface 33 of the housing 14. That is, on the inner peripheral surface 33, the remaining portion other than the rough surface processed portion 42 is the non-roughened surface processed portion 43. The non-roughened surface processed portion 43 is an area corresponding to the non-bent portion 37 or the closed portion 31 on the inner peripheral surface 33 of the housing 14. The non-roughened surface machined portion 43 extends from a position intersecting the plane including the equator position E of the ball portion 20 in the housing main body portion 30, that is, a bending point of the bending portion 36, to a closing portion 31 on the opposite side of the opening 34. This is the area of the inner peripheral surface 33.

The opening 34 is a portion whose peripheral edge is surrounded by the bent portion 36. The opening 34 is formed in a circular shape. The opening 34 is a portion having the smallest inner diameter dimension inside the housing main body 30. Further, the opening 34 is formed in advance with an inner diameter dimension larger than the outer diameter dimension of the ball portion 20 and the ball sheet 13, and when the ball sheet 13 is housed inside the housing 14, the ball portion 20 and the ball sheet 13 are accommodated. It is surrounded by the bent portion 36 so that the inner diameter dimension is smaller than the outer diameter dimension of. Further, the opening 34 may be formed with a series of expansion portions 44. The expansion portion 44 is formed so as to be inclined so as to gradually expand the diameter from the opening 34 toward one end of the housing 14. The expansion portion 44 is for avoiding interference between the stud portion 21 and the housing 14 when the ball stud 12 swings.

Next, a method of manufacturing the ball joint 10 of the first embodiment will be described.

First, in the forming step, as shown in FIG. 3A, the housing 14 is formed into a bottomed tubular shape having an opening 34 at one end. At this time, the housing 14 is formed in a rectangular shape in which the housing main body 30 does not bend over one end and the housing main body 30 has a constant or substantially constant inner diameter.

Next, after the forming step, the housing 14 is roughened in the rough surface processing step from a predetermined position in the axial direction to a position extending from the opening 34 on the inner peripheral surface 33 as shown in FIG. 3 (b). The processed portion 42 is formed. The rough surface processing portion 42 is performed by a method such as shot blasting or laser processing in which the inner peripheral surface 33 of the housing 14 is physically scraped from the opening 34 side. The roughened surface processed portion 42 is formed so that the surface roughness Ra is within the range of 15 to 45, preferably 20 to 30. As a result, the portion of the inner peripheral surface 33 excluding the portion where the rough surface processed portion 42 is formed becomes the non-rough surface processed portion 43. Although the non-rough surface processed portion 43 is not subjected to rough surface processing, other surface treatment may be performed as long as the surface roughness of the non-rough surface processed portion 43 is smaller than the surface roughness of the rough surface processed portion 42. .. Further, the end surface 46 of one end of the housing 14 may or may not be roughened.

Further, after the rough surface processing step, as an insertion step, as shown in FIG. 3C, a ball sheet 13 rotatably holding the ball portion 20 of the separately formed ball stud 12 is inserted from the opening 34. Insert inside the housing 14.

Then, following the insertion step, as a bending step, as shown in FIG. 3D, the central axis is a portion from the equator position E of the ball portion 20 which is a predetermined position of the housing 14 to one end portion provided with the opening 34. The ball sheet 13 inserted inside is prevented from coming off by bending toward the side by caulking deformation or the like to form a bent portion 36. The end surface 46 (FIG. 3 (c)) of one end of the housing 14 is formed as an expansion portion 44 by a bending step.

After that, although not shown, the ball joint 10 is completed by attaching a dust cover or the like over the ball stud 12 and the housing 14 and covering the opening 34 with the dust cover.

By forming in this way, the roughened surface machined portion 42 of the housing 14 bites into the outer peripheral surface of the seat bent portion 28 of the ball sheet 13 to bring about an anchor effect, and the ball sheet 13 falls off from the housing 14, that is, the seat flow is prevented. To prevent.

That is, according to the first embodiment, rough surface processing is performed from a position corresponding to the equatorial position E of the ball portion 20 which is a predetermined position on the inner peripheral surface 33 of the housing 14 to one end where the opening 34 is located. By forming the portion 42 and forming the bent portion 36 from the position corresponding to the equatorial position E of the ball portion 20, which is a predetermined position in the axial direction of the housing 14, to the one end portion where the opening 34 is located, the housing 14 is formed. Of the inner peripheral surface 33, the entire region that reliably abuts on the outer peripheral surface of the ball sheet 13 can be the roughened surface processed portion 42, and the roughed surface processed portion 42 is made to bite into the outer peripheral surface of the ball sheet 13 to form the housing 14. The holding effect of the ball sheet 13 can be improved.

Further, unlike the conventional method of forming a phosphate film and improving the frictional force with the ball sheet 13 by the dense crystals, the rough surface processing portion 42 undergoes a chemical treatment such as a phosphate treatment. Since it is physically scraped and formed without implementation, there is no need to consider wastewater treatment, and since it can be implemented in a shorter time than phosphate treatment, productivity can be improved and efficient production can be achieved. It can be formed at cost. Further, since the rough surface processing portion 42 is set to the range from the opening 34 of the housing 14 to the bending point of the bending portion 36, efficient production can be performed without performing extra processing. That is, when the ball stud 12 of the ball joint 10 is not loaded, the inner peripheral surface 33 of the housing 14 and the outer peripheral surface of the ball sheet 13 are in contact with each other from the equatorial position E to the opening 34 side. Since it is only the inner part of the bent portion 36, and the range from the closed portion 31 to the bent point of the bent portion 36 does not abut, or even if it abuts, it follows lightly, so that the inner peripheral surface of the housing 14 The range in which 33 can bite into the outer peripheral surface of the ball sheet 13 is limited to the range from the bending point of the bending portion 36 to the opening 34 side, which is one end side. Therefore, by forming the rough surface processing portion 42 only in that range, the maximum anchor effect can be realized in the minimum processing range.

On the other hand, on the inner peripheral surface 33 of the housing 14, the non-roughened surface processed portion 43 located from the bending point of the bent portion 36 to the other end on the side opposite to the opening 34 is not roughened. Therefore, the contact area between the outer peripheral surface of the ball sheet 13 and the inner peripheral surface of the housing 14 does not decrease. Therefore, it is possible to suppress an increase in the load per unit area, suppress a decrease in the contact area as compared with the case where the entire inner peripheral surface 33 is roughened, and suppress a decrease in durability.

In particular, if the surface roughness Ra of the rough surface processed portion 42 is too small, it cannot sufficiently bite into the outer peripheral surface of the ball sheet 13, and if it is too large, the ball sheet 13 may be damaged or productivity may decrease. .. Therefore, in the present embodiment, the surface roughness Ra of the rough surface processed portion 42 is set to 15 to 45, preferably 20 to 30, so that the rough surface processed portion 42 is formed on the outer peripheral surface of the ball sheet 13 and the ball sheet 13 is formed. It is possible to suppress a decrease in the contact area between the inner peripheral surface 33 of the housing 14 and the outer peripheral surface of the ball sheet 13, and to suppress an increase in the load per unit area, while ensuring that the ball is bitten into the ball without damaging the ball sheet. Can be prevented from decreasing.

Further, since the ball sheet 13 is formed of a member softer than the housing 14, the rough surface processed portion 42 can be surely bitten into the outer peripheral surface of the ball sheet 13.

Next, the second embodiment will be described with reference to FIGS. 4 and 5. The same components and operations as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The ball joint 10 of the present embodiment will be described by taking as an example an outer ball joint (OBJ) which is used in the steering device and connects the steering device and the knuckle arm of the suspension device.

The housing 14 includes a cylindrical housing body 51 which is a receiving side member main body and a plug 52 which is a closing member attached to the housing body 51, and the end portion of the housing body 51 is closed by the plug 52. The ball sheet 13 is held inside the housing 14.

The housing body 51 is a portion constituting the peripheral wall of the housing 14. That is, the inner peripheral surface of the housing body 51 is the inner peripheral surface 33 of the housing 14. Therefore, the rough surface processed portion 42 and the non-roughened surface processed portion 43 are formed on the inner peripheral surface of the housing body 51. Further, the housing body 51 has an opening 34 formed at one end in the axial direction, and the peripheral edge of the opening 34 gradually contracts from the equator position E of the ball portion 20 of the ball stud 12 toward one end. It is a bent portion 36 that is bent in advance so as to have a diameter. Further, the other end side of the housing body 51 with respect to the bent portion 36 is a non-bent portion 37. Further, the housing body 51 has an opening 54 formed at the other end in the axial direction. Further, a groove 55 is formed on the outer periphery of the housing body 51 at a position closer to one end in the axial direction. A dust cover is attached to the groove 55 and the outer peripheral surface of the ball stud 12.

The plug 52 is formed in a circular plate shape. The plug 52 is integrally fixed to the housing body 51 by holding the peripheral portion of the plug 52 by the deformed portion 58 obtained by deforming the other end of the housing body 51.

Next, a method of manufacturing the ball joint 10 of the second embodiment will be described.

First, in the forming step, as shown in FIG. 5A, the housing body 51 is provided with an opening 34 at one end, an opening 54 at the other end, and an axial direction at the peripheral edge of the opening 34. It is formed in a tubular shape having a bent portion 36 that shrinks from a predetermined position of the above toward one end.

Next, after the forming step, the housing body 51 is roughened to the opening 34 at the position of the bent portion 36 on the inner peripheral surface 33 as shown in FIG. 5 (b) in the rough surface machining step. Form part 42. The rough surface processing portion 42 is performed by a method such as shot blasting or laser processing in which the inner peripheral surface 33 of the housing 14 is physically scraped from the opening 34 side, as in the first embodiment.

Further, after the rough surface processing step, as an insertion step, as shown in FIG. 5C, a ball sheet 13 that rotatably holds the ball portion 20 of the separately formed ball stud 12 is inserted from the opening 34. Insert inside the housing 14. In this insertion step, the roughened surface processed portion 42 of the housing body 51 bites into the outer peripheral surface of the seat bent portion 28 of the ball sheet 13.

Then, following the insertion step, as a closing step, as shown in FIG. 5D, the plug 52 is arranged in the opening 54 of the housing body 51, and the peripheral edge portion of the opening 54 of the housing body 51 faces the central axis side. The deformed portion 58 is formed by bending due to caulking deformation or the like, and the opening 54 of the housing body 51 is closed by the plug 52 to form the housing 14 to prevent the ball sheet 13 from coming off.

After that, although not shown, the ball joint 10 is completed by attaching a dust cover or the like over the ball stud 12 and the housing 14 and covering the opening 34 with the dust cover.

As described above, according to the second embodiment, the coarse portion extends from the position corresponding to the equatorial position E of the ball portion 20, which is a predetermined position on the inner peripheral surface 33 of the housing 14, to the one end portion where the opening 34 is located. The surface-processed portion 42 is formed, and the housing is formed by forming a bent portion 36 from a position corresponding to the equatorial position E of the ball portion 20, which is a predetermined position in the axial direction of the housing 14, to one end where the opening 34 is located. Of the inner peripheral surfaces 33 of 14, the entire region that reliably abuts on the outer peripheral surface of the ball sheet 13 can be the roughened surface processed portion 42, and the roughed surface processed portion 42 is made to bite into the outer peripheral surface of the ball sheet 13. It is possible to achieve the same effect as that of the first embodiment, such as improving the holding effect of the ball sheet 13 in the housing 14.

Further, in the rough surface processing step, the rough surface processing portion 42 is formed over the inner peripheral surface of the bent portion 36 of the housing body 51 to one end where the opening 34 is located, so that the inner peripheral surface 33 of the housing 14 is formed. Of these, the entire inner peripheral surface of the bent portion 36 that reliably contacts the outer peripheral surface of the ball sheet 13 can be used as the roughened surface processed portion 42, and the roughed surface processed portion 42 is made to bite into the outer peripheral surface of the ball sheet 13 to form a housing. While improving the holding effect of the ball sheet 13 at 14, the rough surface machined portion 42 is formed by physically scraping the inner peripheral surface 33, so that it is more efficient than the case where a film is formed by, for example, chemical treatment. It can be manufactured well.

In each of the above embodiments, the ball joint 10 can be used not only for the steering device of the vehicle but also for, for example, a suspension device and other devices.

The ball joint 10 can be used not only for vehicles but also for any other purpose.

The present invention can be suitably used for a steering device for a vehicle such as an automobile.

10 ball joint
12 Ball stud, which is a member on the ball side
13 Ball sheet that is a holding member
14 Housing that is the receiving side member
20 ball part
33 Inner circumference
34 opening
36 Bent part
42 Rough surface processing part
51 Housing body that is the main body of the receiving side member
52 Plug that is a closing member
54 opening

Claims (7)

A ball-side member having a ball portion and
A holding member that rotatably holds the ball portion and
It is provided with a tubular receiving side member that internally receives the holding member that holds the ball portion.
The receiving side member
An opening formed at one end in the axial direction and
A bent portion that is bent from a predetermined position in the axial direction to one end where the opening is located, and a bent portion.
A ball joint characterized by having a rough surface processed portion formed on the inner peripheral surface from the predetermined position to one end where the opening is located and biting into the outer surface of the holding member. The ball joint according to claim 1, wherein the surface roughness Ra of the roughened surface processed portion is 15 to 45. The ball joint according to claim 1 or 2, wherein the holding member is formed of a member softer than the receiving side member. A method for manufacturing a ball joint including a ball-side member having a ball portion, a holding member that rotatably holds the ball portion, and a tubular receiving-side member that internally receives the holding member that holds the ball portion. And
A forming step of forming the receiving side member into a tubular shape having an opening at one end,
A rough surface processing step of physically cutting the inner peripheral surface of the receiving side member from a predetermined position in the axial direction to one end where the opening is located to form a rough surface processed portion.
An insertion step of inserting the holding member holding the ball portion into the inside of the receiving side member through the opening, and
A bending step is provided in which a portion of the receiving side member from the predetermined position to one end where the opening is located is bent toward the central axis side so that the rough surface processed portion bites into the outer surface of the holding member. A method for manufacturing a ball joint. A method for manufacturing a ball joint including a ball-side member having a ball portion, a holding member that rotatably holds the ball portion, and a tubular receiving-side member that internally receives the holding member that holds the ball portion. And
A tubular receiving side member main body is formed having an opening at one end and an opening at the other end, and a bent portion that shrinks from a predetermined position in the axial direction toward one end at the peripheral edge of the opening. And the forming process
A rough surface processing step of physically cutting the inner peripheral surface of the receiving side member body up to one end where the opening is located at the bent portion to form a rough surface processed portion.
An insertion step of inserting the holding member holding the ball portion into the inside of the receiving side member main body through the opening so that the roughened surface processed portion bites into the outer surface of the holding member.
A method for manufacturing a ball joint, which comprises a closing step of closing the opening of the receiving side member main body with a closing member to form the receiving side member. The rough surface processing step according to claim 4 or 5, wherein the rough surface processing step is a step of physically cutting the inner peripheral surface of the receiving side member so that the surface roughness Ra is a rough surface processed portion of 15 to 45. How to manufacture ball joints. The method for manufacturing a ball joint according to any one of claims 4 to 6, wherein the holding member is formed of a member softer than the receiving side member.

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