JP2006193106A - Double ball joint type suspension - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate a dead zone of a ball joint supporting an arm. <P>SOLUTION: The double ball joint type suspension 10 has a front suspension member 12, a stabilizer bar 16, a shock absorber 18, a stabilizer link 20, and a pair of lower arms 22, 24 extending to the right and left direction from both right and left sides of the front suspension member 12. In the pair of lower arms 22, 24, the inner side end part is connected to the both right and left sides of the front suspension member 12 through joints 26, 28, and the outer side end part is connected to a carrier 36 of an axle 34 through the ball joints 30, 32. A coil spring 38 is provided between the pair of lower arms 22, 24, and a spring force of the spring 38 energizes the pair of lower arms 22, 24 so that they may come closer to each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a double ball joint type suspension, and in particular, a double ball joint type suspension configured such that a pair of arms supporting a wheel is connected to a support member on an axle side disposed inside the wheel via a ball joint. About.

  As one of the suspensions for a steering wheel of a vehicle such as an automobile, for example, an axle disposed inside a front wheel and an outer end portion are connected to an axle carrier via a ball joint, and the inner end portion rotates in one direction. A so-called double ball joint type suspension having a pair of suspension arms connected to a vehicle body via a moving joint is known (for example, see Patent Document 1).

In this double ball joint type suspension, the outer end portions of the pair of lower arms are connected to the carrier of the axle portion via the ball joint, thereby improving the riding comfort and the handling stability. The ball joint also has a metal sphere coupled to the outer end of the lower arm and a bearing that holds the sphere attached to the carrier of the axle, and the sphere fits into a spherical recess formed inside the bearing. Thus, it is configured to be held rotatably. Since the lower arm is connected to the ball joint at the outer end, the degree of freedom of rotation is high, and the wheel rotates around the inner end connected to the ball joint according to vertical movement. Move.
Japanese Patent Laid-Open No. 5-92710

  In the double ball joint suspension described in Patent Document 1, for example, when the direction of the wheel is changed by the operation of the steering wheel, a lateral load is applied to the ball joint to which the pair of lower arms are connected, and the sphere is The direction of the wheel is changed while the spherical concave portion made of resin is pressed to elastically deform the spherical concave portion.

  Therefore, in a state where the wheel is directed in the straight direction, since a lateral load is not applied to the ball joint to which the pair of lower arms are connected, the sphere is fitted and held in the spherical recess. There is a dead zone in which the direction of the wheel does not change until the operation angle reaches a predetermined angle.

  Therefore, the conventional double ball joint suspension has a problem that the driver feels uncomfortable because there is an operation angle at which the orientation of the vehicle is not changed when the driver starts turning the steering wheel. .

  In addition, when the spherical concave portion of the ball joint is worn, play occurs between the spherical body and the spherical concave portion, and there is a possibility that a sense of incongruity due to the dead zone appears more remarkably.

  Accordingly, an object of the present invention is to provide a double ball joint suspension that solves the above-described problems.

  In order to solve the above problems, the present invention has the following means.

  The invention according to claim 1 has a double ball joint type suspension having a pair of arms for supporting a wheel, and connecting ends of the pair of arms to a support member disposed inside the wheel via a ball joint. And a biasing member that biases the arm so as to apply a predetermined preload to the ball joint.

  The invention according to claim 2 is characterized in that the urging member is provided between the pair of arms and urges the pair of arms in a direction approaching each other.

  The invention according to claim 3 is configured such that the pair of ball joints each include a sphere coupled to the arm and a bearing having a spherical recess formed so as to cover the surface of the sphere. The spheres are urged in the direction in which the spheres approach each other by the urging force of the urging member, and the spheres are pressed against the spherical recesses.

  According to a fourth aspect of the present invention, the biasing member is a coil spring, and both ends of the coil spring are hooked by hooking portions provided in the vicinity of the outer end portions of the pair of arms. And

  The invention according to claim 5 is characterized in that the pair of arms is a lower arm that supports a front wheel.

  According to the present invention, since the urging member that urges the arm so as to apply a predetermined preload to the ball joint is provided, the dead zone until the load is applied by operating the steering wheel without the minute play of the ball joint. It is possible to eliminate the delay in the operation of the wheel. In addition, the dead zone due to wear of the ball joint can be eliminated, and the direction of the wheel can be changed at the same time when the driver operates the steering wheel, and the uncomfortable feeling due to the presence of the dead zone can be eliminated.

  According to the present invention, since the urging member is provided between the pair of arms, a constant preload can always be applied to the pair of arms with a relatively simple configuration.

  Further, according to the present invention, since the spheres of the ball joints are urged in the direction in which they approach each other by the urging force of the urging member, the spheres are pressed against the spherical concave portions of the bearings. It is held in a deformed state, and the operation delay of the wheel due to the dead zone until the load is applied by operating the steering wheel can be eliminated.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing an embodiment of a double ball joint suspension according to the present invention. FIG. 2 is a plan view showing an example of a mounting structure on the lower arm.

  As shown in FIG. 1, the double ball joint suspension 10 extends in the left-right direction from the left and right sides of the front suspension member 12, the stabilizer bar 16, the shock absorber 18, the stabilizer link 20, and the front suspension member 12. And a pair of lower arms 22 and 24.

  The pair of lower arms 22 and 24 has inner ends connected to the left and right sides of the front suspension member 12 via joints 26 and 28, and outer ends connected to the carrier (support) of the axle 34 via ball joints 30 and 32. Member) 36.

  The front-side lower arm 22 is provided so as to extend in the lateral direction, and the rear-side lower arm 24 is formed in a curved shape. In addition, a coil spring (biasing member) 38 is mounted between the pair of lower arms 22 and 24, and the pair of lower arms 22 and 24 are urged toward each other by the spring force of the coil spring 38.

  Since the coil spring 38 can be arbitrarily set with a spring constant by changing the size, a spring force corresponding to the load applied to the ball joints 30 and 32 can be applied. Further, in this embodiment, since the coil spring 38 is stretched between the pair of lower arms 22 and 24, a preload can be applied to the pair of ball joints 30 and 32 with one urging member, The number of parts can be reduced as compared with the case where the urging members are individually provided for the arms.

  The stabilizer link 20 is attached so as to connect both ends of the stabilizer bar 16 and the left and right shock absorbers 18. The lower end of the shock absorber 18 is coupled to a carrier 36 of an axle 34 that supports a disc 30 and a tire wheel (not shown) of the brake device. The carrier 36 of the axle 34 is supported by the shock absorber 18 and the lower arms 22 and 24 so as to be movable in the vertical direction.

  As shown in FIG. 2, the front lower arm 22 is a rubber having an axis L <b> 1 whose outer end is connected to the lower end of the carrier 36 via a ball joint 30 and whose inner end extends substantially in the vehicle front-rear direction. The front suspension member 12 is pivotally supported via a joint 26 including a bush. Therefore, the front lower arm 22 is supported so as to be rotatable in the vertical direction about the axis L1 of the joint 26 as a central axis.

  Further, the rear lower arm 24 is connected to the front end via a joint 28 including a rubber bush having a central axis L2 whose outer end is connected to the lower end of the carrier 36 via a ball joint 32 and whose inner end extends in the vertical direction. The suspension member 12 is connected. Therefore, the rear lower arm 24 is supported so as to be rotatable in the horizontal direction about the axis L2 of the joint 28 as a central axis.

  The lower arms 22 and 24 have an axis L3 of the front lower arm 22, that is, a straight line connecting the center of the ball joint 30 and the center of the joint 26, and an axis L4 of the rear lower arm 24, that is, the center of the ball joint 32 and the center of the joint 28. It is attached so as to intersect with the connecting line at the intersection P. The carrier 36 is integrally provided with a knuckle arm (not shown), and a tie rod (not shown) is connected to the tip of the knuckle arm via a ball joint, thereby turning the vehicle. Sometimes the wheel is rotated about the kingpin axis with the carrier 36.

  The joint 28 extends in the vertical direction along the central axis L2 and is fixed to the inner end of the rear lower arm 24 so as to be concentric with the inner cylinder 40 and fixed to the front suspension member 12. It has the outer cylinder 42 and the rubber bush 44 interposed between the inner cylinder and the outer cylinder.

  One end of the coil spring 38 is hooked on a hooking portion 22 a provided on the side surface of the front lower arm 22, and the other end of the coil spring 38 is hooked on a hooking portion 24 a provided on the side surface of the rear lower arm 24. . The latching portions 22a and 24a are provided at positions where the lower arms 22 and 24 face each other and at positions close to the ball joints 30 and 32, respectively. Further, the separation distance between the latching portions 22 a and 24 a is set to be longer than the free length of the coil spring 38 by a predetermined distance.

  Therefore, the coil spring 38 is mounted in a state where it is pulled longer than the free length by a predetermined distance, and urges the latching portions 22a and 24a in a direction approaching each other. The spring force of the coil spring 38 acts on the ball joints 30 and 32 as a preload for eliminating play in the ball joints 30 and 32 as will be described later.

  The ball joints 30 and 32 include spherical balls 30a and 32a, spherical concave portions 30b and 32b into which the balls 30a and 32a are rotatably fitted, and bearings 30c that hold the spherical concave portions 30b and 32b. , 32c.

  The balls 30a and 32a are made of, for example, a metal material such as stainless steel, and are integrally provided at outer end portions of the lower arms 22 and 24. The spherical recesses 30b and 32b are formed of a resin material having a low friction coefficient (for example, tetrafluoroethylene resin) in order to reduce friction with the balls 30a and 32a, and are formed inside the bearings 30c and 32c. Is retained.

  Thus, the ball joints 30 and 32 are configured such that the balls 30a and 32a can be three-dimensionally rotated inside the bearings 30c and 32c, and the balls 30a and 32a and the spherical recesses 30b and 32b. It is the structure which suppresses friction with. Since the coil spring 38 is stretched between the lower arms 22 and 24 adjacent to the ball joints 30 and 32 as described above, the balls 30a and 32a are always urged in the direction of proximity.

  As shown in FIG. 3, in the ball joints 30 and 32, the pressing force F due to the spring force of the coil spring 38 acts as a preload. Therefore, in the ball joints 30 and 32, the balls 30a and 32a are held in a state where the balls 30a and 32a are pressed in one direction (proximity direction) with the pressing force F against the spherical recesses 30b and 32b. The recesses 30b and 32b are elastically deformed so that there is no play.

  Therefore, when the driver operates the steering wheel to change the direction of the front wheel, the balls 30a and 32a do not have an operation of elastically deforming the spherical recesses 30b and 32b. The dead zone disappears, and the operation delay of the front wheels can be eliminated. As a result, the wheels can be supported in a state in which there is no excessive rattling, so that the driver does not feel uncomfortable when operating the steering wheel, and can stably drive the vehicle. In addition, the dead zone due to wear of the ball joints 30 and 32 can be eliminated, and the driver can change the direction of the wheel at the same time when the driver operates the steering wheel, so that the uncomfortable feeling due to the presence of the dead zone can be eliminated.

  In the above-described embodiment, the configuration in which the pair of arms is biased in the direction of approaching each other using the coil spring has been described as an example. However, the present invention is not limited thereto, and it is needless to say that a biasing member other than the coil spring may be used. .

  Moreover, in the said Example, although the structure which tensioned the coil spring between a pair of arms was mentioned as an example, it is good not only as this but the structure which provides a precompression to a ball joint by providing a coil spring for every arm. Of course.

  In the above embodiment, the front wheel suspension has been described, but it goes without saying that the present invention may be used for a rear wheel suspension.

1 is a perspective view showing an embodiment of a double ball joint suspension according to the present invention. It is a top view which shows an example of an attachment structure to a lower arm. It is a figure which shows typically the state in which the preload acted on the ball joint.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Double ball joint type suspension 12 Front suspension member 18 Shock absorber 22 Front lower arm 22a, 24a Latching part 24 Rear lower arm 26, 28 Joint 30, 32 Ball joint 30a, 32a Ball | bowl 30b, 32b Spherical recessed part 30c, 32c Bearing 34 Axle 36 Carrier 38 Coil spring

Claims (5)

In a double ball joint type suspension having a pair of arms for supporting wheels, and connecting end portions of the pair of arms to a support member disposed inside the wheel via a ball joint,
2. A double ball joint type suspension comprising a biasing member for biasing the arm so as to apply a predetermined preload to the ball joint.   2. The double ball joint suspension according to claim 1, wherein the biasing member is provided between the pair of arms and biases the pair of arms in a direction in which the pair of arms approaches each other.   Each of the pair of ball joints includes a sphere coupled to the arm and a bearing having a spherical concave portion formed so as to cover the surface of the sphere, and the spheres are connected to each other by the urging force of the urging member. 3. The double ball joint suspension according to claim 2, wherein the spherical body is urged in the approaching direction and is pressed against the spherical concave portion.   4. The biasing member according to claim 1, wherein the biasing member is a coil spring, and both ends of the coil spring are latched by latching portions provided in the vicinity of the outer end portions of the pair of arms. Double ball joint suspension as described in 1.   The double ball joint suspension according to any one of claims 1 to 4, wherein the pair of arms are lower arms that support a front wheel.

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