JP3054341B2 - Ball joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball joint, and more particularly to a ball joint suitable as a joint for a vehicle suspension.

[0002]

2. Description of the Related Art Conventionally, ball joints have been used as joints for vehicle suspensions. The ball joint realizes swingable connection by sliding a ball stud sliding portion in a ball seat. In order to make the movement of the ball stud smooth, it is necessary to appropriately hold the ball stud sliding portion in the ball seat.

[0003] As a ball joint for realizing such a function, for example, a configuration disclosed in Japanese Utility Model Publication No. 5-5288 has been conventionally known. The above-mentioned publication discloses a ball joint in which a ball stud sliding portion is held by two ball sheets engaged with each other.

[0004]

When two ball seats are engaged with each other, a gap is easily formed between the sliding portion of the ball stud and the ball seat when the ball seat is worn. If such a gap occurs, play will occur in the ball joint, and proper operation cannot be obtained. However, the above-mentioned conventional ball joint is configured to absorb the play of the ball joint while keeping the two ball seats in the engaged state. For this reason, even if the ball seat is slightly worn, play may occur. In this sense, the above-mentioned conventional ball joint has a problem that it is early detected that it is unusable.

As a method of absorbing the backlash of the ball joint, a method of pressing a ball seat using a spring is considered. In this case, play does not occur even if wear occurs. However, if there is no backlash, it may be difficult to detect the wear state in the market, and there is a problem that it takes time for inspection and the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above point, and by restricting the displacement of an axially movable ball seat, no rattling occurs when the wear of the ball seat is below an allowable value. It is another object of the present invention to provide a ball joint which operates normally when the wear of the ball seat exceeds the maximum allowable value, and the play is generated and the occurrence of excessive wear can be detected.

[0007]

The above object is achieved by the present invention.
As described in the above, a ball stud sliding portion is gripped by a first ball seat urged in a predetermined direction by an urging means, and a second ball seat separated from the first ball seat. A ball joint comprising: a first ball seat and a second ball seat;
A first engagement portion that engages with each other in the predetermined direction;
Provided on the first ball seat and the second ball seat.
And engaged with each other around an axis having the predetermined direction as an axis.
2 of the first ball seat
The predetermined direction and the shaft circumference with respect to a second ball seat
This is achieved by providing a displacement restricting means for restricting each displacement within a predetermined value.

[0008] In addition, as described in claim 2, the first
One of the ball seat or the second ball seat,
The circumferential width of the other ball seat side end is smaller at the tip.
A projection formed so as to be eliminated, and
The ball seat is attached to the end of the one ball seat side.
Opposite side of the one ball seat so as to fit with the protrusion
Is formed so that the circumferential width of the end of the
The first engaging portion includes the convex portion and the front portion.
The concave portion is constituted by an engaging surface in the direction around the axis, and
The second engaging portion is a circumferential width of the convex portion and the concave portion.
In the part formed so that
It may be configured by a mating surface .

[0009]

According to the first aspect of the present invention, the first ball seat is pressed toward the ball stud sliding portion by the urging means , so that the ball stud sliding portion is held at an appropriate pressure. When the wear of the sliding surface is equal to or less than the predetermined amount, the first ball seat moves to the ball stud sliding portion side, and the holding pressure of the ball stud sliding portion is maintained at an appropriate pressure. on the other hand,
When the wear of the sliding surface progresses beyond a predetermined amount, the displacement restricting means suppresses the movement of the first ball seat toward the ball stud sliding portion. For this reason, a gap is formed between the first ball seat and the ball stud sliding portion, and as a result, rattling occurs in the ball joint. Also, displacement regulation
The means makes the predetermined direction of the first ball seat around the axis.
The displacement around the axis is restricted within a predetermined value. Therefore, the first
The displacement around the axis between the ball seat and the biasing means is restricted.
As a result, sliding between the two is prevented.

According to the second aspect of the present invention, the first baud
One of the ball seats or the second ball seat
The circumferential width of the end on the side of the seat is smaller at the tip
And the other ball seat has
Is fitted to the convex portion at one end of the ball seat side.
The circumferential width of the other end of the ball seat on the opposite side
And a recess formed so that the tip becomes smaller toward the tip.
You . The first engagement portion is configured to extend around the axis of the protrusion and the recess.
And a second engaging portion,
The width in the circumferential direction of the convex portion and the concave portion becomes smaller toward the tip.
Constituted by the engagement surface in the formed portion
You . For this reason, when assembling the first and second ball sheets with each other, even if the phases of the respective ball sheets in the rotation direction are shifted, the shift is automatically corrected in the process of assembling.
Therefore, according to the second aspect of the present invention, the work of assembling the first ball seat and the second ball seat can be facilitated.

[0011]

FIG. 1 is an enlarged sectional view of a ball joint 10 according to an embodiment of the present invention. The ball joint 10 includes a ball stud 20 fixed to the connected member 14. The ball stud 20 is a rigid member made of metal, and includes a spherical portion 20a and a shaft portion 20b. Shaft 2
A thread groove is formed at the end of Ob. On the other hand, a through hole 14a is formed in the connected member 14, and the ball stud shaft portion 20b is fixed by a nut 21 through the through hole 14a.

The lower sheet 38 is a resin member formed in a generally cylindrical shape and has a ball stud spherical portion 20a.
Is held on the inner peripheral surface. One end (the lower end in FIG. 1) of the lower sheet 38 is formed in a spherical shape so that the diameter becomes smaller toward the end so as to follow the shape of the ball stud sphere 20a. The lower sheet 38 is arranged on the inner peripheral surface of the socket 30. One end (the lower end in FIG. 1) of the inner peripheral surface of the socket 30 is formed in a spherical shape so that its diameter becomes smaller toward the end so as to follow the outer peripheral shape of the lower sheet 38.

The upper sheet 36 is a two-stage cylindrical resin member having a through hole 36a. The lower end of the upper sheet 36 is formed in a spherical shape so as to follow the shape of the ball stud sphere 20a. The through hole 36a has a small diameter in the vicinity of the contact portion with the spherical body portion 20a, and has a large diameter in an upper portion thereof.

The dust cover 24 is a cylindrical flexible member whose central portion is swollen. The upper part is in close contact with the lower part of the socket 30, and the lower part is in close contact with the outer peripheral surface of the ball stud shaft part 20b near the attachment part to the connected member 14. The dust cover 24 prevents dust from entering the sliding portion,
Prevents the enclosed grease from flowing out. Since the dust cover 24 has flexibility, it is deformed in accordance with the rotation and swing of the ball stud 20. Cap 32 is socket 3
It is fixed to the upper end of 0 by caulking. The hollow portion 44a formed by the cap 32 and the upper portion of the through hole 36a of the upper sheet 36, and the hollow portion 44b formed by the lower surface of the upper sheet 36, the ball stud sphere portion 20a and the lower sheet 38 form a grease reservoir 44. Lubricating grease is sealed in the grease reservoir 44 in order to reduce sliding friction between the ball stud sphere 20a and the upper sheet 36 and the lower sheet 38.

The hollow portion 44a has an upper sheet 3
A backup spring 34 for urging the ball 6 toward the ball stud sphere 20a is provided. For this reason,
The ball stud spherical portion 20a is held at a constant pressure by the lower sheet 38 and the upper sheet 36. According to such a configuration, the upper sheet 36 and the lower sheet 38
Thereby, the ball stud sphere portion 20a is rotatably supported.

FIG. 2 is a front view of the upper sheet 36, and FIG.
Shows a front sectional view of the lower sheet 38. As shown in FIG. 3, four oil grooves 46 are provided on the inner surface of the lower sheet 38 uniformly in the circumferential direction in the axial direction. Thus, the oil groove 46
Is provided, the grease in the grease reservoir 44 is supplied to the entire surface of the ball stud sphere 20a.

As shown in FIGS. 2 and 3, the upper sheet 36
The lower end of the lower sheet 38 and the upper end of the lower sheet 38
0 and 42 are provided. In the present embodiment, the upper sheet 36 and the lower sheet 38
It is characterized in that 0 and 42 are provided. Hereinafter, FIG.
With reference to FIG. 7, the engagement portions 40 and 42 will be described.

As shown in FIG. 2, the large diameter portion of the upper sheet 36 is provided with an engaging portion 40 which is convex on the outer peripheral surface. On the other hand, as shown in FIG. 3, an engagement portion 4 formed in a concave shape to be fitted with the engagement portion 40 of the upper sheet is provided at an end of the inner peripheral surface of the lower sheet 38 on the engagement side with the upper sheet 36.
2 are provided. Since the top 40a of the engaging portion 40 is seated on the top 42a of the engaging portion 42, the axial movement of the upper seat 36 toward the lower seat 38 is suppressed.

FIG. 4 shows the cap 3 of the ball joint 10.
2 shows a plan view when 2 is removed. Upper sheet 36
As shown in FIG.
Are assembled in a state where they are engaged. Engaged portion 40,4
2, a slight clearance is provided in the radial direction, and the upper sheet 36 can slide in the axial direction. Therefore, the ball stud 20 is held at an appropriate pressure by the backup spring 34, and can maintain a stable sliding state.

FIG. 5 is an enlarged sectional view of the ball joint 10 in which deterioration with time has not occurred. In FIG. 5, a gap L is provided between the top 40 a of the engaging portion 40 of the upper sheet 36 and the top 42 a of the engaging portion 42 of the lower sheet 38. For this reason, the upper seat 36 can move in the axial direction of the ball stud 20, and the upper seat 36 is pressed by the ball stud sphere 20 a by the backup spring 34. As a result, the ball stud sphere 20a is held at an appropriate pressure by the upper sheet 36 and the lower sheet 38.

FIG. 6 shows the ball joint 10 in a state where the wear 70 at one end (the lower end in FIG. 6) of the sliding surface of the lower seat 38 has progressed due to the sliding of the lower seat 38 and the ball stud sphere 20a. In FIG. 6, the ball stud 20 and the upper seat 36 move downward in the figure, and as a result, the gap between the top 40a of the engaging portion 40 and the top 42a of the engaging portion 42 becomes zero.

In the process from the state shown in FIG. 5 to the state shown in FIG. 6, that is, when the wear 70 of the lower sheet 38 is smaller than the wear amount (hereinafter referred to as critical wear amount) W in FIG. There is a gap between the top 40a of the joint 40 and the top 42a of the engagement portion 42. In this case, since the upper sheet 36 can be displaced downward in the drawing, the upper sheet 36 is pressed against the ball stud sphere 20a by the backup spring 34. As a result, the ball stud sphere 20a
Is maintained at an appropriate pressure by the upper seat 36 and the lower seat 38, and the ball joint 10 operates normally.

FIG. 7 shows a state in which the lower sheet wear 70 has exceeded the critical wear amount W. In FIG. 7, the ball stud sphere portion 20a is shown in FIG.
It is moving down and down. On the other hand, since the top 40a of the engaging portion 40 of the upper seat 36 is seated on the top 42a of the engaging portion 42 of the lower seat 38,
It is not possible to move further downward in the figure from the state of.
As a result, a gap d is generated between the sliding surface of the upper sheet 36 and the ball stud sphere 20a. In this state, the load of the backup spring 34 is not applied to the ball stud sphere portion 20a, so that the ball joint 10 rattles.

As described above, in the ball joint 10 according to the present embodiment, the wear 7 of the lower seat 38 is reduced.
0 until reaches a critical wear amount W is top 4 of the engaging portion 40
0a and a gap exists between the top 42a of the engagement portion 42.
Therefore, the upper sheet 36 may be displaced downward in the drawing.
it can. For this reason, the upper seat 36 is
Pressed against ball stud sphere 20a by pulling 34
As a result, the holding pressure of the ball stud sphere 20a is maintained at an appropriate pressure. For this reason, no play occurs in the ball joint 10, and the ball joint 10 can operate normally. On the other hand, when the wear 70 of the lower sheet 38 exceeds the critical wear amount W, the top 40
a is seated on the top portion 42a of the engagement portion 42, and the upper seat 3
6 cannot move further downward in the figure, so that the ball joint 10 starts to rattle. Therefore, by detecting this play, it can be easily detected that the wear 70 of the lower sheet 38 has exceeded the critical wear amount.

The critical wear amount W, that is, the magnitude of wear at which rattling starts is determined by the top portion 40a of the engaging portion 40 and the top portion 42 of the engaging portion 42 when the ball joint is assembled.
It can be adjusted by changing the size of the gap L provided between the gap L. Therefore, the gap L between the engaging portions 40 and 42 is provided so that the critical wear amount W matches the maximum allowable value of the wear of the lower sheet 38 (the limit value of the wear that allows the lower sheet 38 to be used as a sliding surface). Thereby, the ball joint can be maintained in a normal state until the wear reaches the maximum allowable value.

When the difference between the unloaded length of the backup spring 34 (hereinafter, referred to as free height) and the height of the hollow portion 44a of the upper sheet 36 where the backup spring 34 is attached is small, the lower seat 38 The upper sheet 36 moves downward in FIG.
The height of the hollow portion 44a may be larger than the free height of the backup spring 34. In this case, the holding pressure by the backup spring 34 becomes zero. As a result, the backup spring 34 and the upper seat 36
Can move in the axial direction of the ball stud 20, and there is a possibility that abnormal noise may occur. In addition, ball joint 10
It can also cause play.

On the other hand, in this embodiment, the height of the hollow portion 44a when the wear of the lower sheet 38 reaches the maximum allowable value is smaller than the free height of the backup spring 34. Spring 3
4 free height and the like are set. According to such a configuration,
The holding pressure by the backup spring 34 does not become zero, and the above problem does not occur.

By the way, when the engagement portion 40 of the upper sheet and the engagement portion 42 of the lower sheet are assembled so as to be fitted as described above, the relative rotation of the upper sheet 36 and the lower sheet 38 can be prevented. If the relative rotation of the upper seat 36 and the lower seat 38 is prevented, the upper seat 36 and the backup spring 34 do not rotate with the rotation of the ball stud 20. In addition, if the backup spring 34 does not rotate, no sliding occurs between the backup spring 34 and the cap 32, and noise and abrasion caused by sliding of both can be prevented. In this regard, the ball joint of the present embodiment has an excellent effect in terms of quietness and the like.

As shown in FIG. 2 and FIG.
Each of 0 and 42 is formed in a shape in which the width becomes narrower toward the tip. According to such a shape, the lower sheet 3
When assembling the upper sheet 36 and the upper sheet 36, even if the two sheets 36 and 38 are slightly out of phase in the rotational direction, the deviation is automatically corrected during the assembling process. Therefore, according to the lower sheet 38 and the upper sheet 36 of the present embodiment, the assembling operation can be facilitated.

Next, an example in which the ball joint 10 according to the present embodiment is applied to a vehicle suspension mechanism will be described. FIG. 8 shows a perspective view of the present suspension mechanism. As shown in FIG. 8, each wheel FL, FR, RL,
The RRs are supported by suspension mechanisms provided correspondingly. Hereinafter, as a representative example, a configuration of a suspension mechanism provided corresponding to the right front wheel FR will be described.

FIG. 9 is a rear view of the right front wheel suspension mechanism shown in FIG. As shown in FIG. 9, the vehicle suspension of the present embodiment has two ball joints 10,
It comprises an upper arm 13, a shock absorber 15, a knuckle 16, a coil spring 17, a wheel 18, and a lower arm 64.

One end of the lower arm 64 is fixed to the body 19, and the other end is connected to the knuckle 16 by the lower ball joint 10. The knuckle 16 is a member connected to the wheel 18 via a bearing 70, and the upper end thereof is connected to the upper arm 13 by the upper ball joint 10. The other end of the upper arm 13 is swingably movable through a bush (not shown).
It is connected to. The upper end of the coil spring 17 and the upper end of the shock absorber 15 disposed on the inner periphery of the coil spring 17 are fixed to the body 19. Also,
The lower end of the shock absorber 15 is connected to a predetermined position of the lower arm 64. The connection between the shock absorber 15 and the lower arm 64 is performed via the joint 11, and both are connected so as to be able to rotate relative to each other.

According to this configuration, when the wheel 18 moves up and down, the coil spring 17 and the shock absorber 15 expand and contract, and the two ball joints 10 and the joint 11 rotate.
Is prevented from being transmitted to the body 19. Further, since the lower arm 64 and the upper arm 13 are rotatably connected to the knuckle 16 via the upper and lower ball joints 10, respectively, the above-described operation can be performed even during the steering operation. By the way, when the ball joint is used for a vehicle suspension mechanism, it is necessary to replace the ball joint when the wear of the ball seat reaches a limit value. On the other hand, in a ball joint where the holding pressure is maintained by the backup spring even after the wear of the ball seat reaches the limit, even if the ball joint cannot function properly, No backlash occurs. Therefore, for such a ball joint, it is not possible to detect the progress of wear by detecting backlash. Further, since the worn portion is shielded inside the ball joint, it is difficult to visually detect the wear from the outside. If it is difficult to detect wear, the use of the ball joint may be continued in a state where the wear exceeds the maximum allowable value, that is, in a state where the lower seat 38 is worn out, without noticing the progress of wear. is there.

On the other hand, when the biasing force of the backup spring is not applied to the ball seat, the abrasion of the sliding portion appears directly as the backlash of the ball joint.
It is easy to detect wear. However, according to such a configuration, as described above, it is difficult to ensure the durability of the ball joint because there is a possibility that the ball joint may play due to the slight wear.

On the other hand, according to the ball joint 10 of this embodiment, whether or not the wear exceeds the maximum allowable value can be easily detected by detecting the play of the ball joint 10. . Therefore, when the ball joint 10 is used, it is possible to prevent the generation of abnormal noise and the deterioration of steering feeling due to the deterioration of the performance of the ball joint 10 during running of the vehicle.

Next, with reference to FIG. 10, a method of detecting play in a suspension mechanism using the ball joint 10 of this embodiment will be described. However, FIG. 10 shows a state where the tire is removed. Ball joint 1
The play of the suspension mechanism of the vehicle incorporating 0 is
The vehicle can be easily detected by jacking up the vehicle and applying a vertical force to the tire while the tire is lifted off the ground. In this case, if the tire moves up and down with a relatively small force, it means that the ball joint 10 is loose.

Further, as shown in FIG. 10, according to the method of measuring the backlash with the dial gauge 50, the amount of wear at the lower end of the lower sheet 38 can be accurately measured. In FIG. 10, the base 51 of the dial gauge 50 is shown.
Is fixed to the lower arm 64. On the other hand, the stylus 52 of the dial gauge 50 is applied to the lower socket 30 of the ball joint 10 via the knuckle 16 from below. A dedicated tool 54 is attached to the axle hub 70 integrated with the knuckle 16 via a bearing. In this state, by applying a constant vertical load to the axle hub 70 and reading the measured value of the dial gauge 50 with the special tool 54, the amount of vertical displacement of the axle hub 70 relative to the lower arm 64 is measured. Since the axle hub 70 is connected to the lower arm 64 by the lower ball joint 10 via the knuckle 16, the amount of vertical displacement becomes the size of the play of the ball joint 10. Since there is a correlation between the size of the play and the amount of wear at the tip of the lower sheet 38, if the size of the play is measured, the amount of wear can be accurately estimated.

As described above, according to the ball joint 10 of the present embodiment, the play can be easily and reliably detected. Therefore, the necessity of replacing the ball joint 10 can be easily determined in the market, and excellent serviceability can be obtained. In the above-described embodiment, the upper sheet 36 corresponds to the first ball sheet, and the lower sheet 38 corresponds to the second ball sheet.
The ball stud sphere portions 20a correspond to the above-mentioned ball stud sliding portions, respectively.

[0039]

As described above, according to the first aspect of the present invention, when the wear of the second ball seat is within a predetermined value, the ball joint is prevented from rattling at the ball stud sliding portion. Can operate normally. Further, when the wear of the sliding portion of the second ball seat exceeds a predetermined value, a gap is formed between the ball stud sliding portion and the first ball seat, thereby causing play in the ball joint. be able to. Therefore, according to the ball joint according to the present invention, by detecting the backlash of the ball joint, it can be easily detected whether or not the wear of the sliding portion exceeds the maximum allowable value. The replacement of the second ball seat can be performed. Ma
In addition, the displacement restricting means controls the displacement around the axis with the predetermined direction as the axis.
Is also regulated within a predetermined value, so that the rotation of the first ball seat
Rotation can be regulated. For this reason, the urging means and the first button
Can be prevented from sliding with the seat.
Noise and friction caused by sliding between the two can be prevented.
You.

According to the second aspect of the present invention, the first
Work of the first ball seat and the second ball seat
Can be facilitated .

[Brief description of the drawings]

FIG. 1 is a sectional view of a ball joint according to an embodiment of the present invention.

FIG. 2 is a front view of an upper sheet according to the present embodiment.

FIG. 3 is a front sectional view of a lower sheet according to the present embodiment.

FIG. 4 is a plan view when a cap of the ball joint of the present embodiment is removed.

FIG. 5 is an enlarged sectional view of a sliding portion of the ball joint according to the present embodiment in a state where deterioration with time has not occurred.

FIG. 6 is an enlarged cross-sectional view of the sliding portion when the wear of the lower seat of the ball joint of the present embodiment reaches a critical wear amount.

FIG. 7 is an enlarged cross-sectional view of the sliding portion when the wear of the lower seat of the ball joint of this embodiment exceeds a critical wear amount.

FIG. 8 is a perspective view of a suspension mechanism using the ball joint of the present embodiment.

FIG. 9 is a rear view of the suspension mechanism for the right front wheel using the ball joint of the embodiment.

FIG. 10 is a diagram illustrating a method for detecting wear of the lower seat in the present embodiment.

[Explanation of symbols]

 Reference Signs List 10 ball joint 20 ball stud 20a ball stud ball portion 34 backup spring 36 upper seat 38 lower seat 40, 42 engaging portion 40a, 42a top

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuhiro Ishikawa 10 in Hamadashita, Nakahata-machi, Nishio-shi, Aichi Prefecture (72) Inventor Tetsuo Kondo 10-ten, Hamatashita, Nakahata-machi, Nishio-shi, Aichi, Japan 72) Inventor Yoshimi Suzuki 10 Hamadashita, Nakahata-cho, Nishio-shi, Aichi Pref. Otics Co., Ltd. Field surveyed (Int.Cl. ⁷ , DB name) F16C 11/06

Claims (2)

(57) [Claims] Gripping the ball stud sliding portion in the first and the ball seat, and a second ball seat which is the first ball seat and the separate is biased in a predetermined direction by 1. A biasing means A ball joint comprising: a first ball seat and a second ball seat;
First engagement portions provided and engaged with each other in the predetermined direction
And the first ball seat and the second ball seat
Are provided on the axis, and mutually around an axis having the predetermined direction as an axis.
More becomes a second engaging portion engaged, the predetermined direction 及 for said second ball seat of the first ball seat
And a displacement restricting means for restricting the displacement around the axis within a predetermined value. 2. The first ball seat or the second ball seat.
One of the ball seats is located at the other ball seat side end.
Protrusion formed so that the width in the circumferential direction becomes smaller at the tip
And the other ball seat is provided on the one ball seat side.
Of the one ball bearing so as to fit with the convex portion.
The circumferential width of the end on the opposite side to the
And the first engagement portion is configured so that the shaft portion of the protrusion and the recess has the same circumference.
And the second engaging portion is formed in a circumferential direction of the convex portion and the concave portion.
At the part formed so that the width of the
2. The ball joint according to claim 1, wherein the ball joint is formed by an engaging surface .