JP5546467B2 - Ball joint member mounting structure - Google Patents

Description

  The present invention relates to an attachment structure for attaching a ball joint member that supports a knuckle to a lower arm used in an automobile suspension.

  In an independent suspension type suspension such as a strut type or a double wishbone type, a ball joint may be used to support the knuckle on the lower arm. When using a ball joint, there are a system in which a socket is formed on the lower arm and a ball stud is attached, and a system in which a ball joint member formed so that the arm extends from the socket is joined to the lower arm. As a method of joining a ball joint member to a lower arm, an arm extended from a socket is overlapped on a lower arm and fastened at two locations in the vehicle width direction using bolts and nuts (for example, patents) Reference 1).

  In addition, when the ball joint member is joined to the lower arm, a large load is applied to the joint portion on the outer side in the vehicle width direction, and therefore, as shown in FIG. Socket 114 side) is formed to be wide, and is fastened at two locations on the outer side in the vehicle width direction, and the ball joint member 110 and the lower arm 101 are fastened at a total of three locations including one location on the inner side in the vehicle width direction. Some of them are

JP 61-282106 A

  However, in the ball joint member mounting structure of Patent Document 1, since a large load is applied to the bolt nut on the outer side in the vehicle width direction, if a bolt nut having a size capable of withstanding this load is used, the bolt nut on the inner side in the vehicle width direction is used. Is unnecessarily large and uneconomical. Here, it is conceivable that the bolt nut on the inner side in the vehicle width direction is made smaller than that on the outer side in the vehicle width direction, but in this way, two types of tools having different sizes can be used when the ball joint member and the lower arm are joined. It must be used, and the assembly work becomes complicated.

  On the other hand, in the mounting structure that fastens the ball joint member 110 shown in FIG. 3, not only the number of parts increases and the fastening work becomes complicated, but also the lower arm 101 is formed wider because the arm 112 becomes wider. This must lead to an increase in size and weight of the member.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a ball joint member mounting structure that can simplify the assembling operation without increasing the size and weight.

  In order to solve the above problems, the present invention provides a ball joint member (11) having a ball joint portion (11) for supporting the knuckle (3) and an arm portion (12) extending from the ball joint portion in the vehicle width direction. 10) is a ball joint member mounting structure for mounting to the lower arm (1). The arm portion of the ball joint member is formed with a female screw hole (16) on the outer side in the vehicle width direction, and in the vehicle width direction. A male screw shaft (17) is projected on the inner side, and through holes (21, 22) are formed in the lower arm at positions corresponding to the female screw hole and the male screw shaft. The ball joint member and the lower arm are arranged on the inner side in the vehicle width direction. Are fastened by a nut (24) screwed into a male screw shaft inserted through the through hole and a bolt (23) inserted into a through hole on the outer side in the vehicle width direction and screwed into the female screw hole. Shaft diameter (D1) is larger than the shaft diameter of the externally threaded shaft (D2), and a bolt of a two-surface width (S1) and nut dihedral width and (S2) is equal to or is identical. Here, the two-sided width is a width between two parallel side surfaces in a bolt head and a nut having a plurality of two sides parallel to the side surfaces, such as a square, a hexagon, and an octagon.

  According to this configuration, it is possible to prevent the arm portion and the lower arm from becoming large and heavy by providing two fastening portions. Also, the required performance of the member is achieved by using a large-diameter bolt for the fastening part on the outer side in the vehicle width direction where a larger load is applied and using a small-diameter male screw shaft for the fastening part on the inner side in the vehicle width direction where a smaller load is applied. The member cost can be reduced while satisfying the above. On the other hand, in the joining operation, since the male screw shaft projects from the arm portion in the vehicle width direction, it is easy to align the ball joint member and the lower arm. In addition, since both the nut and the bolt may be tightened from the lower arm side, the number of tightening points is small and the tightening operation is easy. Furthermore, since the two-sided width of the bolt and the two-sided width of the nut are the same, the bolt and the nut can be tightened without changing the tool, and the tightening operation can be further facilitated.

  Further, according to one aspect of the present invention, the portion of the arm portion in which the through hole on the inner side in the vehicle width direction is formed is thinner than the portion of the arm portion in which the through hole on the outer side in the vehicle width direction is formed, and the male screw shaft is It can be formed by a knurled bolt (19).

  According to this configuration, it is possible to ensure the strength of the arm portion of the portion where the through hole on the outer side in the vehicle width direction where stress is concentrated is formed, and it is possible to ensure the required shear strength by increasing the length of the female screw hole. . In addition, the ball joint member can be reduced in size and weight by thinning the portion of the arm portion in which the through-hole is formed on the inner side in the vehicle width direction. Furthermore, by forming the male screw shaft with a knurled bolt, the male screw shaft can be easily formed on the arm portion.

  As described above, according to the present invention, it is possible to provide a ball joint member mounting structure that can simplify the assembling work without causing an increase in size and weight.

The top view of the attachment structure of the ball joint member concerning the present invention II-II sectional view in FIG. Plan view of mounting structure of ball joint member according to the prior art

  Hereinafter, an embodiment of a mounting structure for a ball joint member 10 according to the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1 and 2, the lower arm 1 is a link member that connects a vehicle body 2 and a knuckle 3 of an automobile so as to be relatively movable up and down, and in this embodiment, a strut type applied to a front wheel 4. Used as a component of suspension. In FIGS. 1 and 2, only the left suspension is shown. The knuckle 3 rotatably supports the front wheel 4 via a wheel bearing (not shown), and turns the front wheel 4 left and right by driving the tie rod 5 connected to the front end to the left and right. A strut assembly 6 having a spring and a damper (not shown) is attached to the upper end of the knuckle 3. The spring absorbs the input from the front wheel 4, and the damper can converge the periodic vibration of the spring. ing.

  The lower arm 1 and the knuckle 3 are connected to each other via a ball joint member 10 so as to be rotatable. The ball joint member 10 includes a ball joint portion 11 that supports the knuckle 3 and an arm portion 12 that extends from the ball joint portion 11, and the ball joint portion 11 is a ball stud that is fixed to the knuckle 3. 13, a socket 14 that is formed integrally with the arm portion 12 and holds the ball portion 13 a of the ball stud 13, and a dust boot 15 that covers a sliding contact portion between the ball stud 13 and the socket 14.

  The arm portion 12 of the ball joint member 10 is formed with a female screw hole 16 on the base end side, that is, on the outer side in the vehicle width direction when attached to the automobile, and on the inner side in the vehicle width direction on the distal end side, that is, attached to the automobile. A male screw shaft 17 is projected from the front. The terms of the base end side (vehicle width direction outer side) and the distal end side (vehicle width direction inner side) specify the relative positional relationship between the female screw hole 16 and the male screw shaft 17, and the center of the arm portion 12 is specified. The position is not specified as a reference.

  The male screw shaft 17 is formed by a shaft portion of a knurled bolt 19 that is press-fitted into a through hole 18 provided in the arm portion 12 from a side opposite to the protruding direction of the male screw shaft 17. A serration extending in the axial direction is formed at the axial base end of the knurled bolt 19 over the entire circumference. When the serration is fitted into the inner peripheral surface of the through-hole 18 by press-fitting, the knurled bolt 19 is 12 is fixed to be non-rotatable. On the other hand, the lower arm 1 is formed with two through holes 21 and 22 arranged in the vehicle width direction at positions corresponding to the female screw hole 16 and the male screw shaft 17 formed in the arm portion 12.

  The ball joint member 10 and the lower arm 1 include a flanged hex nut 24 screwed into the male screw shaft 17 in a state where the male screw shaft 17 is inserted into the through hole 22 on the inner side in the vehicle width direction, and an outer side in the vehicle width direction. It is inserted into the through-hole 21 and fastened by a flanged hexagon bolt 23 screwed into the female screw hole 16 of the arm portion 12.

  The shaft diameter D1 of the flanged hexagon bolt 23 is larger than the shaft diameter of the knurled bolt 19, that is, the shaft diameter D2 of the male screw shaft 17 (D1> D2). On the other hand, the two-surface width (width between two parallel side surfaces) S1 of the flanged hexagon bolt 23 is the same as the two-surface width S2 of the flanged hexagon nut 24 (S1 = S2). Here, since a standard product is used for the flanged hexagonal nut 24, the standard in which the flanged hexagonal bolt 23 has a non-standard dimension, that is, a two-sided width S1 smaller than specified with respect to the shaft diameter D1 (nominal diameter of the screw). Formed with outer dimensions.

  Further, the arm portion 12 of the ball joint member 10 has a step that is thinner on the distal end side (vehicle width direction inner side) where the knurled bolt 19 is attached than on the base end side (vehicle width direction outer side) where the female screw hole 16 is formed. It has a shape. Therefore, the axial length L1 of the female screw hole 16 is longer than the axial length of the through hole 18 (L1> L2).

  In the mounting structure configured as described above, the ball joint member 10 is mounted to the lower arm 1 as follows. First, the ball joint member 10 to which the knurled bolt 19 is fixed is put on the lower arm 1 by inserting the male screw shaft 17 into the through hole 22 on the inner side in the vehicle width direction. And a hexagon bolt 23 with a flange is inserted into the through hole 21 on the outer side in the vehicle width direction from the lower arm 1 side and screwed into the female screw hole 16. And the hexagon nut 24 with a flange and the hexagon bolt 23 with a flange are tightened using a tool. Thereby, it fastens at two places, the fastening part by the hexagon nut 24 with a flange and the knurled bolt 19, and the fastening part by the hexagon bolt 23 with a flange and the internal thread hole 16, and the ball joint member 10 and the lower arm 1 are integrated. Be joined.

  Thus, since the fastening part to the lower arm 1 of the ball joint member 10 is made into two places, the arm part 12 of the ball joint member 10 can be made thinner than those fastened at the conventional three places. The arm portion 12 and the lower arm 1 can be prevented from being increased in size and weight. And since the clearance between the lower arm 1 and the knuckle 3 or the front wheel 4 (wheel) can be increased by making the joint portion between the ball joint member 10 and the lower arm 1 thinner, the turning angle (cut angle) of the front wheel 4 Can be made larger or can be applied to smaller wheels.

  Further, the shaft diameter D1 of the flanged hexagon bolt 23 disposed on the outer side in the vehicle width direction to which a larger load is applied is made larger than the shaft diameter D2 of the male screw shaft 17 disposed on the inner side in the vehicle width direction to which a smaller load is applied. Accordingly, it is possible to reduce the cost by avoiding the use of an unnecessarily large member while satisfying the required performance of the member according to the arrangement.

  Further, since the male screw shaft 17 protrudes from the inner portion of the arm portion 12 in the vehicle width direction, it is easy to align the ball joint member 10 and the lower arm 1 during assembly. Then, since the two members of the flanged hexagon nut 24 and the flanged hexagon bolt 23 are both tightened from the lower arm 1 side, the number of tightening points is small and the tightening operation is facilitated. Furthermore, since the two-sided width S1 of the flanged hexagon bolt 23 and the two-sided width S2 of the flanged hexagonal nut 24 have the same dimensions, both members can be tightened without exchanging tools, and the tightening work is further enhanced. Is facilitated.

  On the other hand, the portion of the arm portion 12 in which the through hole 18 on the inner side in the vehicle width direction is formed is thinner than the portion on which the female screw hole 16 on the outer side in the vehicle width direction is formed. The strength of the portion 12 can be secured, and the required shear strength of the female screw hole 16 can be secured by increasing the thickness of the female screw hole 16 portion. Further, the ball joint member 10 can be reduced in size and weight by thinning the portion of the arm portion 12 where the through hole 18 on the inner side in the vehicle width direction is formed. Further, since the male screw shaft 17 is formed by the knurled bolt 19, the male screw shaft 17 can be easily formed on the arm portion 12.

  Although description of specific embodiment is finished above, the aspect of the present invention is not limited to the above embodiment. For example, in the above embodiment, the mounting structure of the ball joint member 10 to the lower arm 1 is applied to the strut suspension of the front wheel. It is also possible to apply to the suspension of the above. Moreover, in the said embodiment, although the external threaded shaft 17 formed in the ball joint member 10 is formed with the knurled bolt 19, you may form with the welt bolt which can be fixed to the arm part 12, or a stud bolt. Furthermore, in the said embodiment, although the standard product is used for the hexagon nut 24 with a flange, and the hexagon bolt 23 with a flange is formed in the dimension outside a standard, the standard product is used for the hexagon bolt 23 with a flange, and a hexagon nut with a flange 24 may be formed to a non-standard dimension having a dihedral width S2 larger than specified with respect to the nominal diameter of the screw. In addition, instead of using the flanged hexagonal bolt 23 and the flanged hexagonal nut 24 as bolts and nuts, those without flanges, square or octagonal bolts and nuts may be used. In addition, specific configurations such as the shapes of the lower arm 1 and the ball joint member 10 can be appropriately changed as long as they do not depart from the spirit of the present invention. In addition, all the components shown in the above embodiment are not necessarily essential, and can be appropriately selected without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Lower arm 3 Knuckle 10 Ball joint member 11 Ball joint part 12 Arm part 16 Female screw hole 17 Male screw shaft 19 Knurled bolt 21 Through hole (vehicle width direction outer side)
22 Through hole (inner side in vehicle width direction)
23 Hexagon bolt with flange 24 Hexagon nut with flange D1 Shaft diameter (Hexagon bolt 23 with flange)
D2 Shaft diameter (Male threaded shaft 17)
S1 Width across flats (Hexagon bolt 23 with flange)
S2 Width across flats (Flanged hex nut 24)

Claims (2)

A ball joint member mounting structure for mounting a ball joint member having a ball joint portion supporting a knuckle and an arm portion extending from the ball joint portion in the vehicle width direction to a lower arm,
The arm portion of the ball joint member has a female screw hole formed on the outer side in the vehicle width direction, and a male screw shaft protruding from the inner side in the vehicle width direction.
A through hole is formed in the lower arm at a position corresponding to the female screw hole and the male screw shaft,
The ball joint member and the lower arm are inserted into the through hole on the inner side in the vehicle width direction and screwed into the male screw shaft, and inserted into the through hole on the outer side in the vehicle width direction, and screwed into the female screw hole. Fastened with bolts,
2. The ball joint member mounting structure according to claim 1, wherein a shaft diameter of the bolt is larger than a shaft diameter of the male screw shaft, and a two-surface width of the bolt and a two-surface width of the nut are the same. The portion in which the through hole on the inner side in the vehicle width direction in the arm portion is formed is thinner than the portion in which the through hole on the outer side in the vehicle width direction in the arm portion is formed
The ball joint member mounting structure according to claim 1, wherein the male screw shaft is formed by a knurled bolt.

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