JP2005082053A - Suspension arm, forged suspension member, and forging die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a forged suspension member allowing compact formation of a ball joint part by securing strength for the dimension of the ball joint part and reflection of the compact formation of the ball joint part on the length of an arm part, a suspension arm having a wide degree of freedom in design by securing strength, and a forging die allowing forging by considering an interference region. <P>SOLUTION: A parting line P1 of the ball joint part is formed as a peripheral edge line P1b along a peripheral edge of either one of one end face part 3f or the other end face part 4f at a position in the range to be the interference region 1F in a side surface part 5f. The line P1 is formed to be continuous to a parting line of the arm part 6 from both ends of the peripheral edge line P1b at a position in the side surface part 5f in the range from the outside of the interference region IF up to the arm part 6f. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a suspension arm that is used as a suspension member disposed around a wheel of an automobile or the like and is attached via a stud bolt that becomes an engagement structure, and a forged suspension for machining and forming the suspension arm. The present invention relates to a member and its forging die.

  In general, an undercarriage member for an automobile such as a suspension arm attached to a support member such as a knuckle or a carrier supported on the axle side of an automobile or the like via a joining structure joined to a ball stud bolt has a predetermined length. An arm portion including: a ball joint portion for supporting the ball stud bolt on one end side of the arm portion; and a vehicle body side engagement portion engaged with a vehicle body side such as a sub member on the other end side of the arm portion. Various things have been proposed.

  For example, as a suspension arm, in order to improve steering stability, the distance between the fulcrum points from the ball joint part to the other joint part (vehicle body side engaging part) is increased, or the joint of the ball joint part is increased. It is known that by making the center closer to the tire center, the scrub radius (distance between the intersections of the center line of the wheel and the upper and lower joints on the tire contact surface) can be reduced, and the torque steer can be reduced. Therefore, it is desired that the ball joint dimensions in the suspension arm be reduced.

  In addition, since the installation environment in which the suspension arm is installed is in the vicinity of the wheel of the automobile, the installation space is limited, and there is a restriction in the case of the suspension arm that realizes the configuration of the arm part that increases the distance as described above. There is. Therefore, in the suspension arm, it is desired to increase the degree of design freedom by reducing the shape of the ball joint portion.

  On the other hand, the suspension arm is made of steel, and the structure including the steel ball joint portion is formed by press molding, so the ball joint portion tends to be large (for example, Patent Document 1). Therefore, conventionally, the suspension arm is made of aluminum alloy instead of steel material, the ball joint part and arm part are integrated, and the ball joint part is formed small, so the arm part is formed long. Those that are superior to steel in terms of strength and weight have been proposed (for example, Patent Document 2).

  In addition, the suspension arm formed by machining a forged suspension member formed of an aluminum alloy has a ball joint portion 102 formed integrally with the arm portion 106 by forging as shown in FIG. An insertion hole for inserting the ball portion 134 of the stud bolt 133 is machined, and the ball stud bolt 133 is inserted with an interposition member 138 composed of a plurality of parts (omitted from the drawing and shown as one part) interposed. It is configured to be assembled.

  When the suspension arm 100 is forged as a forged suspension member before being machined, a parting line PL is formed in the arm portion 106 and the ball joint portion 102. The ball joint portion 102 is configured to be disposed at substantially the center position, and is formed so that the center of the side surface portion 105 protrudes.

  The arm portion and the ball joint portion are each forged with a machining allowance and with a draft angle. In addition, the suspension arm is subjected to a large stress (such as pull-out strength) because force is applied to the ball joint portion in the direction in which the ball stud bolt moves in and out, for example, while the vehicle is running. In order to maintain the above, a certain amount of material volume must be secured.

  Further, in the forging die for forging the forging suspension member, the parting surface corresponding to the parting line is set in a horizontal direction which is a direction orthogonal to the forging press direction (perpendicular direction). . Therefore, in the forging die, the position that is substantially centered with respect to the thickness direction on the side surface of the forged suspension member is a split surface that is arranged in the horizontal direction, and the arm portion and the ball joint portion of the forged suspension member have a thickness direction. In contrast, a parting line is formed substantially at the center.

JP-A-10-37944 (paragraph numbers 0013 to 0017) JP 2000-355206 A (paragraph numbers 0010 to 0015)

However, the conventional forged suspension member or the forged mold configuration of the suspension arm or the forged suspension member formed by the forged suspension member has the following problems.
In the conventional forged suspension member, the parting line is arranged at the center in the thickness direction on the side surfaces of the ball joint part and the arm part, so it is necessary to provide a large draft angle on both sides from the parting line. In addition, since it is necessary to increase the thickness of the dimension-added portion necessary for the draft, the size of the ball joint portion has increased.

  Further, in the conventional forged suspension member, since the parting line is arranged at the center in the thickness direction on the side surfaces of the ball joint portion and the arm portion, the draft angle is about the variation margin of the remaining burr length caused by forging trimming. In addition to the increased wall thickness, it is necessary to consider by adding dimensions to secure the interference area with each member supported on the wheel axle when joined to the knuckle of the wheel via a ball stud bolt was there. For this reason, in the suspension arm formed of the forged suspension member, it is restricted to bring the ball joint portion close to the wheel, and the degree of freedom in design is hindered.

Furthermore, in the structure of the conventional forged suspension member, the grain flow is concentrated and the parting line which is the weakest part is almost in the center, which is disadvantageous to the pull-out load of the stud bolt, and there is a limit to downsizing.
In addition, in the suspension arm formed by machining from a conventional forged suspension member, the ball portion of the ball stud bolt is not set in relation to the interference area at the outermost diameter of the ball joint portion. It was difficult to ensure the degree of freedom in designing the ball joint part while maintaining the pullout strength of the ball part of the stud bolt.

  And in the forging die of the conventional forging suspension member, since the setting line is arranged in the horizontal direction perpendicular to the forging press direction, the position of the parting line can be changed by changing the forging posture. Even if it is out of the position of the interference region, priority is given to placing the parting line in the horizontal direction perpendicular to the forging press direction, thus promoting the downsizing of the ball joint part of the forged suspension member to be forged It was difficult to do.

  The present invention was devised in view of the above-mentioned problems, and can be formed compactly while ensuring strength with respect to the dimensions of the ball joint part, and the length of the arm part can be reduced to the extent that the ball joint part can be formed compactly. The purpose of this is to provide a forged suspension member that can be reflected in the height, a suspension arm that ensures strength and has a wide range of design freedom, and a forging die that can be forged in consideration of the interference area. And

  In order to achieve the above object, the present invention has the following configuration. That is, the forged suspension member according to the present invention is a ball joint part that is attached to a support member supported on the axle side of an automobile via a stud bolt so as to be rotatable and avoid an interference area with axle side parts. A forged suspension member for forming a suspension arm having an arm by machining, wherein the forged suspension member includes an arm portion, a ball joint portion provided at one end of the arm portion, and a vehicle body provided at the other end of the arm portion. A side engaging portion, and a parting line formed continuously at predetermined positions of the arm portion, the ball joint portion, and the vehicle body side engaging portion, and the ball joint portion includes one end surface portion, It is formed across the other end surface portion facing the one end surface portion, the other end surface portion and the one end surface portion. A parting line of the ball joint part as a peripheral line along a peripheral edge of either the one end face part or the other end face part at a position in a range of the interference part in the side face part. At the position in the side surface portion that is formed and in the range from the outside of the interference region to the arm portion, it is formed so as to continue from both ends of the peripheral line to the parting line of the arm portion (claims). 1).

  By being configured in this way, the forged suspension member has a parting line that is a peripheral line disposed on the entire side surface that is an interference region in the ball joint portion, and a parting line that is formed on the side surface that is an interference region. The burr portion due to the above and the protruding portion of the thickened portion due to the draft are minimized (zero draft, no thickening).

  In addition, a suspension arm having a ball joint portion that is attached to a support member supported on the axle side of the automobile so as to be rotatable via a stud bolt and so as to avoid an interference area with the axle side part is formed by machining. In the forged suspension member, the forged suspension member includes an arm portion, a ball joint portion provided at one end of the arm portion, a vehicle body side engaging portion provided at the other end of the arm portion, and the arm portion. A parting line continuously formed at a predetermined position of the ball joint part and the vehicle body side engaging part, the ball joint part having one end face part and the other end face part facing the one end face part, The other end surface portion and a side surface portion formed over the one end surface portion, and a par of the ball joint portion. The wing line is formed as a peripheral line along the peripheral edge of either the one end surface part or the other end surface part at the position on the side surface part which is the farthest position from the arm part, and the arm extends from both ends of the peripheral line. At the position on the side surface in the range up to the part, formed as an inclined line inclined with respect to the normal from either end of the peripheral line to the other peripheral edge of the one end surface part or the other end surface part, and In addition, the first end surface portion or the other end surface portion is formed as a continuous line that continues from the other peripheral edge to the parting line of the arm portion (claim 2).

  With this configuration, the forged suspension member has a parting line arranged in a peripheral line shape on the whole or a part of the interference region in the ball joint portion, and the draft angle of the side surface portion becomes zero or minimum. , Protrusion due to thickening can be suppressed. In the inclined line portion, a draft is formed toward the one end surface portion and the other end surface portion with the inclined line as a boundary.

  In addition, a suspension arm having a ball joint portion that is attached to a support member supported on the axle side of the automobile so as to be rotatable via a stud bolt and so as to avoid an interference area with the axle side part is formed by machining. In the forged suspension member, the forged suspension member includes an arm portion, a ball joint portion provided at one end of the arm portion, a vehicle body side engaging portion provided at the other end of the arm portion, and the arm portion. A parting line continuously formed at a predetermined position of the ball joint part and the vehicle body side engaging part, the ball joint part having one end face part and the other end face part facing the one end face part, The other end surface portion and a side surface portion formed over the one end surface portion, and a par of the ball joint portion. The wing line is formed as a peripheral line along the peripheral edge of either the one end surface part or the other end surface part at the position on the side surface part which is the farthest position from the arm part, and the arm extends from both ends of the peripheral line. At the position on the side surface in the range up to the part, formed as an inclined line inclined with respect to the normal from either end of the peripheral line to the other peripheral edge of the one end surface part or the other end surface part, and In addition, the one end surface portion or the other end surface portion is formed as a continuous line that continues from the other peripheral edge to the parting line of the arm portion (claim 3).

  By being configured in this way, the forged suspension member is formed continuously with the parting line of the arm portion from the position where the inclined line-shaped parting line exceeds the interference region, The draft angle formed can be reduced, the strength required for the shape of the ball joint part can be obtained with the minimum necessary material volume, and it is advantageous for the interference area in the wheel of an automobile, and the scrub radius can be reduced. Can be small.

Furthermore, in the forged suspension member, the peripheral line of the parting line in the ball joint portion is configured such that at least one of the inclined base points serving as both ends thereof is disposed outside the interference region.
By being configured in this way, the forged suspension member can maintain a state where the side surface portion is vertical at the center position of the interference region in the ball joint portion, and the width of the design can be widened.

  Further, a suspension arm having a ball joint portion which is attached to a support member supported on the axle side of the automobile so as to be rotatable via a stud bolt and to avoid an interference area with the axle side part is formed by machining. In the forged suspension member, the forged suspension member includes an arm portion, a ball joint portion provided at one end of the arm portion, a vehicle body side engaging portion provided at the other end of the arm portion, and the arm portion. A parting line continuously formed at a predetermined position of the ball joint part and the vehicle body side engaging part, the ball joint part having one end face part and the other end face part facing the one end face part, A side surface portion formed over the other end surface portion and the one end surface portion, and the side of the ball joint portion The parting line in the part is an inclined line that is inclined with respect to a normal line from the peripheral edge of the one end surface part to the peripheral edge of the other end surface part, and the peripheral edge of the one end surface part or the peripheral edge of the other end surface part from the inclination base point of the inclined line And a continuous line extending from the peripheral line to the parting line of the arm portion, and at least one of the inclined base points that are both ends of the inclined line is in the interference region. (Claim 5).

  By configuring in this way, the forged suspension member can be used as a suspension arm when an inclined line-shaped parting line is formed at a position shifted to the left or right from the center in the interference region at the ball joint portion. Then, the side surface along the perpendicular can be formed in the side surface portion of the ball joint portion which is the farthest position from the arm portion. In addition, even when an inclined line-shaped parting line is formed in the state of being in the center of the interference area, the draft can be configured to be minimal, so that the bulge can be minimized when machining the suspension arm. it can.

  In addition, a suspension arm having a ball joint portion that is attached to a support member supported on the axle side of the automobile so as to be rotatable via a stud bolt and so as to avoid an interference area with the axle side part is formed by machining. In the forged suspension member, the forged suspension member includes an arm portion, a ball joint portion provided at one end of the arm portion, a vehicle body side engaging portion provided at the other end of the arm portion, and the arm portion. A parting line continuously formed at a predetermined position of the ball joint part and the vehicle body side engaging part, the ball joint part having one end face part and the other end face part facing the one end face part, A side surface portion formed over the other end surface portion and the one end surface portion, and a side surface of the ball joint portion. The parting line is inclined from the peripheral edge of the one end surface portion to the peripheral edge of the other end surface portion, and from the inclination base point of the inclined line to the peripheral edge of the one end surface portion or the peripheral edge of the other end surface portion. And a continuous line that continues from the peripheral line to the parting line of the arm portion, and an inclined base point that is both ends of the inclined line is formed at a position outside the interference region. (Claim 6).

  With this configuration, the forged suspension member has a ball joint portion in which the parting line is formed along the periphery in the interference region in the ball joint portion, and the farthest position from the arm portion when the suspension arm is formed. In the side surface portion, a side surface along the perpendicular can be formed in the interference region.

  In the forged suspension member, the peripheral line in the parting line of the ball joint portion is arranged at a position to be removed by machining (Claim 7). By being configured in this way, even if the parting line position in the interference region is formed by being arranged in a direction from the position along the periphery to the center in the thickness direction depending on the forging posture, machining is performed. Therefore, it is removed when the suspension arm is formed, so that no protrusion is formed. In the case of adjusting the burr outflow direction, the parting line is disposed at a position where the burr is removed by machining.

  The suspension arm formed by machining from the forged suspension member has a radius of the ball diameter of the stud bolt as R1, and a distance from the center of the ball joint portion to the outermost part in the interference region of the ball joint portion. When R2 is R2, the ball joint portion is formed at a ratio of 1.2 <R2 / R1 ≦ 1.9. (Embodiment 8) With this configuration, the suspension arm can maintain the strength of the ball joint portion and can increase the degree of freedom in design.

In the suspension, the pull-out strength and the punch-out strength of the stud bolt are 25 kN or more (claim 9). Thus, by setting the pull-out strength of the suspension arm to 25 kN or more, it becomes possible to counteract the impact during running.
Further, in the suspension arm, the forged suspension member is made of an Al—Mg—Si based aluminum alloy having an average area ratio of sub-crystal grains in the structure of 80% or more and a 0.2% proof stress of 290 MPa or more. (Claim 10).
With this configuration, the suspension arm is made of a high-strength aluminum alloy, and the wall thickness can be reduced while maintaining the holding force of the ball portion of the ball joint portion.

Furthermore, in the forging die used for the forging suspension member having the above-described configuration, the forging posture of the forging suspension member is such that the tilt base point corresponding to the tilted parting line of the ball joint portion deviates from the interference region. It was set as the structure forged in the state inclined in the direction (Claim 11).
By being configured in this manner, the forging die can be forged as a forging suspension member that can be avoided without forming a portion protruding in the buffer region of the ball joint portion.

The present invention has excellent effects as described below.
The forged suspension member forms a parting line so that there is no protrusion to the interference area of the suspension arm formed by machining, and the grain flow is connected to one end surface portion or the other end surface portion of the ball joint portion. Therefore, the ball joint portion can be reduced in size while minimizing the waste caused by the draft and maintaining the strength. Also, in the finished product such as suspension arm, the parting line burr remaining length does not need to be considered in the tire interference area, so the joint center of the joint part can be brought closer to the tire center, and the degree of freedom of design is expanded. In addition, the scrub radius can be reduced.

  Also, the forged suspension member has a small draft angle and a grain flow ball joint when an inclined parting line is formed in the interference region of the suspension arm formed by machining. Since it is formed so as to be configured toward the peripheral edge of the other end surface portion, the strength can be maintained and the ball joint portion can be reduced in size. Therefore, the joint center of the joint portion can be brought close to the tire center, the degree of freedom in design can be increased, and the scrub radius can be reduced.

  Further, the forged suspension member is disposed at a position where the parting line formed in the interference region is removed by machining, so that there is no protruding portion with respect to the interference region of the ball joint portion. In addition, the strength of the ball joint portion can be maintained and the size can be reduced.

  Since the suspension arm defines the radius of the ball diameter of the ball stud bolt and the distance to the outermost diameter of the ball joint so as to be within a predetermined range, the strength of the ball joint is maintained. The degree of freedom of design for achieving miniaturization in the state can be expanded. Furthermore, in the suspension arm, the side wall of the ball joint portion can be slimmed by using a high-strength aluminum material or satisfying the conditions for the pulling strength and the punching strength.

  In addition, the forging die can be adjusted by adjusting the forging posture so that the position of the tilt base point of the tilted line-shaped parting line of the ball joint portion that is originally arranged in the interference area is outside the interference area. It becomes possible to forge, and it becomes possible to provide a forged suspension member that can achieve a reduction in size of the ball joint portion.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view in which a part of the mounting position of the suspension arm is omitted, FIG. 2 is a side view of a state in which a part of the suspension arm is broken, and FIG. 3 is a cross-sectional state of the ball joint portion of the suspension arm. FIGS. 4A to 4E are schematic views showing the positions of the parting lines of the forged suspension member, and FIGS. 5A and 5B are examples of two types of suspension arms as a whole. Are respectively plan views schematically shown. In each figure, the reference numeral indicating the forged suspension member will be described by adding “f” to the reference numeral attached to the suspension arm.

  As shown in FIG. 1 and FIGS. 5A and 5B, the suspension arm 1 includes an arm portion 6, a joint portion 2 formed at one end of the arm portion 6, and the other end of the arm portion 6. The vehicle body side engaging part 9 is formed. The suspension arm 1 is forged as a forged suspension member 1f (see FIG. 3) with an aluminum alloy or the like and then machined from the forged suspension member 1f (see FIG. 3). The joint portion 2 is rotatably supported with respect to the interference region IF (see FIG. 3) via a ball stud bolt (stud bolt) 33 of a support member (knuckle, carrier, etc.) 32 constituting the suspension. The side engaging portion 9 is engaged and supported at an engaging position on the vehicle body side (not shown) of the axle 31. As shown in FIG. 4, the interference area IF is described as a range of 100 degrees from the center of the ball joint portions 2f and 2 (see FIG. 3) as an example, but is limited to this range. It is not a thing. The axle side parts that interfere with the interference area IF are parts such as brake drums and wheels.

  As shown in FIG. 2, the ball stud bolt 33 interposed between the support member 32 (see FIG. 1) and the suspension arm 1 includes a screw portion 35 fixed by a nut for engaging with the support member 32, and the screw portion. A body part 36 continuing from 35 and a ball part 34 provided at an end of the body part 36 are provided. When the ball stud bolt 33 is supported by the joint portion 2, the ball portion 34 can be freely set in a 360 ° direction with respect to the stud bolt neutral direction (direction perpendicular to the one end surface portion 3) SN. In addition, the joint portion 2 is supported by being engaged (or directly without using the interposition member 38) via an interposition member 38 composed of a plurality of parts (shown as one part here).

  As shown in FIGS. 5 (a) and 5 (b), the suspension arm 1 has a complicated shape with a non-axisymmetrical wheel, such as one having two vehicle body side engaging portions 9 or only one. In many cases, it has the same strength and corrosion resistance as iron materials, and therefore, A6061 and its derivatives 6000 series, and aluminum alloys such as high-strength aluminum alloy materials are used. An example of the high-strength aluminum alloy material is an Al—Mg—Si-based aluminum alloy having an average area ratio of sub-crystal grains in the structure of 80% or more and a 0.2% proof stress of 290 MPa or more.

  In aluminum alloys, the proportion of sub-crystal grains in the forged material structure has a greater effect on the strength, toughness and corrosion resistance of the forged material than the refinement of the crystal grains in the forged material structure (contribution). To do. That is, by increasing the ratio of the sub-crystal grains in the forged material structure, it is possible to achieve high strength, high toughness and high corrosion resistance of the forged material with good reproducibility. In other words, even if the average crystal grain size of the forged material structure is refined to 50 to 80 μm by high-temperature forging, the average area ratio of sub-crystal grains finer than the crystal grain size should be small in the forged material structure. Therefore, it is impossible to achieve high strength, high toughness, and high corrosion resistance of the forged material with good reproducibility.

  Therefore, if the average area ratio of the sub-crystal grains in the forged material structure is 60% or more, the 0.2% proof stress of the forged material can be 290 MPa or more, and the stress corrosion cracking resistance can be improved. Further, when the average area ratio of the sub-crystal grains is preferably 90% or more, the 0.2% proof stress of the forged material can be increased from 350 MPa or more, along with the stress corrosion cracking resistance.

  The measurement of sub-crystal grains of this high-strength aluminum alloy material is performed by electrolytically etching the microstructure measurement cross section of the forged material, in particular, by clarifying the sub-crystal grain boundaries and the crystal grain boundaries, This is done after discriminating between the boundaries and sub-crystal grains. At this time, in order to take into account variations due to the forged material parts, it is performed by observing 20 fields of view where the positions of measurement (data collection) are changed at the parts where the strength and corrosion resistance of each forged material are required. Then, the average area ratio of the sub-crystal grains is measured by visual processing or image processing for the area occupied by the sub-crystal grains for each visual field, and the area ratio of the sub-crystal grains relative to the one visual field area is calculated, The area ratio of the sub-crystal grains in 20 fields is averaged to obtain the average area ratio (%) of the sub-crystal grains.

  A forged suspension member 1f for forming the suspension arm 1 by machining is forged by a forging die 10 (see FIG. 8) including an upper die 11 and a lower die 12. FIG. 2 shows that the stud bolt neutral direction SN of the ball stud bolt 33 is in a state perpendicular to the arm plane. Note that the forging die 10 is configured to have a parting surface 13 that is inclined at a predetermined angle at the positions of the arm portion 6f and the ball joint portion 2f.

As shown in FIG. 3 and FIG. 4, the parting line PL of the forged suspension member 1f is such that the position of the parting line P2 of the arm portion 6f is arbitrary from the upper end side to the lower end side in the thickness direction E on the side surface of the arm portion 6f. However, it is formed so as to be located in the center here. The parting line P1 of the ball joint portion 2f is formed by a peripheral line P1b along the periphery of the one end surface portion 3f or the other end surface portion 4f and a continuous line P1a continuous to the parting line P2 of the arm portion 6f. Yes.
In the ball joint portion 2f, the parting line PL is formed via an inclined line P1c in which the continuous line P1a is inclined at a predetermined inclination angle θ with respect to the perpendicular SL from the one end surface portion 3f toward the other end surface portion 4f. Sometimes it is done.

  As shown in FIGS. 3 and 4, in the parting line P1 of the ball joint portion 2f, the peripheral line P1b is formed along the periphery of the one end surface portion 3f or the other end surface portion 4f in the range of the interference region IF. Further, the peripheral line P1b is continuously formed even at the position of the side surface portion 5f beyond the interference region IF, and is formed to a predetermined length. The length of the peripheral line P1b in the side surface part 5f beyond the interference region IF, that is, the positions of the inclination base points A1 and A2 of the peripheral line P1b is the side part 5f of the ball joint part 2f beyond the interference region IF to the arm part 6f. Any position may be used as long as it is within, and it is preferably disposed at a position symmetrical to the position of the side surface portion 5f which is the farthest position from the arm portion 6f. Of course, an asymmetric position may be used. Here, the term “formed along the periphery” means both ends of a curved line when a curved line exists at one end surface part 3f of the ball joint part 2f or the boundary part between the other end surface part 4f and the side surface part 5f. It is said that the peripheral line P1b is formed at a position on one end side in the predetermined range d on the side surface portion 5f side within the range or the processing removal range K described later and within the predetermined range d of the inclined line. Shows the state.

  Further, as shown in FIG. 3, the range in the thickness direction of the ball joint portion 2f where the peripheral line P1b is formed is removed by machining when the suspension arm 1 is formed by machining from the forged suspension member 1f. Any position within the processed removal range K may be used. That is, as shown in FIG. 5, the parting line P1 is arranged along the processing removal range K or the peripheral edge at the farthest position from the arm portion 6f or the side surface portion 5f of the ball joint portion 2f that is the interference region IF. This is because the grain flow GF by forging is formed toward the periphery.

  Note that the peripheral line P1b requires a draft when approaching the center of the ball joint portion 2f in the thickness direction. Therefore, in the ball joint portion 2f, the processing removal range K (including the range d) is an optimum range for forming the peripheral edge portion P1b when considering the state of projecting outward in the side surface portion 5f. .

  As shown in FIG. 3 and FIG. 4, when it continues from the inclination base points A1 and A2 of the peripheral line P1b to the parting line P2 of the arm part 6f, a predetermined inclination angle θ is reached to the height position of the parting line P2 of the arm part 6f. It is formed as a continuous line P1a continuous so as to connect the parting line P2 of the arm portion 6f. If the configuration of the parting line P1 continuing from the peripheral line P1b to the parting line P2 of the arm portion 6a is such that the parting line P2 of the arm portion 6f and the peripheral line P1b can be smoothly connected, It may be a straight line, a curved line, or a combination of a straight line and a curved line. 3 and 4, the parting line P1 of the ball joint part 2f is formed so as to be continuous with the parting line P2 of the arm part 6f via the inclined line P1c and the continuous line P1a. The peripheral line P1b is formed to the vicinity of the arm portion 6f, and the peripheral line P1b and the inclined line P1c or the continuous line P1a (including the configuration of the continuous line inclined at the inclination angle of the inclined line P1b). You may be comprised by either.

Further, the inclination line P1c preferably has an inclination angle θ of 45 degrees or less with respect to the perpendicular SL from the inclination base point A1 or A2 of the peripheral line P1b, and more preferably has an inclination angle θ of 30 degrees or less. When the inclination angle θ of the inclination line P1c is 45 degrees or less, the range for adding the draft is shortened, and the protrusion length to the outside can be reduced accordingly. Note that trimming becomes difficult in the deburring process at an angle approaching the perpendicular SL, for example, 5 degrees or less (please confirm).
In addition, the inclined line P1c is shown here as being formed from the one end surface portion 3f toward the other end surface portion 4f to the center in the thickness direction of the ball joint portion 2f, but from the one end surface portion 3f to the other end surface portion 4f. If it is in the range, it may be formed from one end surface portion 3f to the other end surface portion 4f, or may be formed below the center in the thickness direction of the ball joint portion 2f.

  A draft angle is formed on the side surface portion 5f at the position of the inclined line P1c. This draft is formed at 3 degrees or less toward the one end face part 3f and the other end face part 4f with the inclined line P1c as a boundary, preferably 2 degrees or less, and more preferably 1 degree or less. If the draft is 3 degrees or less, there is little waste, and if it is 1 degree or less, the draft is minimal.

  As shown in FIGS. 3 and 4, the continuous line P1a that continues from the end of the inclined line P1c to the parting line P2 of the arm portion 6f is a straight line (horizontal line) having the same height as the parting line P2. Is formed. The continuous line P1a is formed in a horizontal line shape as shown in FIG. 3 depending on how far the end of the inclined line P1c is formed, or an inclined line shape connecting the parting line P2 of the arm portion 6f. Alternatively, it is formed in a curved shape (not shown).

  The configuration of the parting line P1 in the ball joint portion 2f of the forged suspension member 1f is inclined with respect to the perpendicular line SL from the one end surface portion 3f to the other end surface portion 4f with respect to the peripheral line P1b and the continuous line P1a. The formation position of the inclined line P1c inclined at the angle θ may be different (see FIGS. 7 and 8). 6 (a), 6 (b) and 7 (a), 7 (b) schematically show other configurations of the parting line in the ball joint portion of the forged suspension member as a front perspective view and left and right side views. It is a schematic diagram. 3 and 4 are denoted by the same reference numerals and description thereof is omitted, and the already-described peripheral line P1b, continuous line P1a, and inclined line P1c are formed at different positions, but the configuration is the same. Therefore, in the following description, the description about the position is mainly used.

  As shown in FIG. 7A, the parting line P1 in the ball joint portion 2f is formed so as to straddle the range in which one inclined line P1c becomes the interference region IF as a portion different from FIGS. And the relationship with the other inclined line P1c is formed at a position shifted by 180 degrees. As described above, when the inclined line P1c is formed across the range to be the buffer region IF, it is better to use the continuous line P1a continuous from the position beyond the interference region IF to the parting line P2 of the arm portion 6f. As a draft, the necessary meat is small.

  Next, as shown in FIG. 6B, the parting line P1 in the ball joint portion 2f is formed along the periphery of the other end surface portion 4f in the side surface portion 5f up to the arm portion 6f including the interference region IF. The peripheral line P1b, and the inclined lines P1c and P1c formed so that the predetermined inclination angle θ is 45 degrees or less with respect to the normal SL from the inclination starting points A1 and A2 of the peripheral line P1b to the peripheral edge of the one end surface portion 3f. The continuous lines P1a and P1a formed continuously from the inclined lines P1c and P1c to the parting line P2 of the arm 6f along the peripheral edge of the one end surface portion 3f. As shown in FIG. 6 (b), when the parting line P2 of the arm portion 6f is formed at the end in the thickness direction of the arm portion 6f, even if it is at a position beyond the interference region IF, it is inclined. The lines P1c and P1c may be formed from the one end surface portion 3f to the other end surface portion 4f.

Further, as shown in FIG. 7 (a), the parting line P1 in the ball joint portion 2f has a predetermined inclination angle with respect to the normal SL from the one end surface portion 3f to the other end surface portion 4f within the interference region IF. An inclination line P1c formed with θ being 45 degrees or less, a peripheral line P1b formed along one edge base point A1 of the inclination line P1c along the periphery of the other end face portion 4f, and the other inclination base point of the inclination line P1c. Each of the peripheral lines P1b formed along the peripheral edge of the one end surface portion 4f from A2 and the peripheral lines P1b of the one end surface portion 3f and the other end surface portion 4f is formed to be continuous with the parting line P2 of the arm portion 6f. Continuous lines P1a and P1a. As shown in FIG. 7A, in the parting line P1 in the ball joint portion 2f, the peripheral line P1b may be formed at two locations.
In addition, along with the formation of the inclined line P1c within the range that becomes the interference region IF, it is necessary to add a sagging for a draft, but it is 3 degrees or less or 2 degrees or less, more preferably 1 degree or less. By making the draft angle of, the amount of protrusion from the side surface portion 5f can be reduced.

  Further, as shown in FIG. 7B, the parting line P1 in the ball joint portion 2f forms an inclined line P1c having a predetermined inclination angle θ of 45 degrees or less so as to straddle the interference area IF. It does not matter as a structure to do. That is, the parting line P1 is formed such that at least one of the inclination base point A1 or the inclination base point A2 of the inclination line P1c is outside the interference region IF. Further, the inclined line P1c may be configured such that both inclined base points A1 and A2 are arranged outside the range of the interference region IF. The parting line P1 has an interference region of the side surface portion 5 in the ball joint 2 when the suspension arm 1 is set such that the inclined line P1c is shifted from the center of the interference region IF to both sides (arm portion 6f side). The amount of protrusion from the IF can be limited to a small amount.

  As described with reference to FIGS. 6 and 7, the parting line P1 in the ball joint portion 2f reduces the amount of protrusion from the side surface portion 5f in the interference region IF, thereby causing the suspension arm 1 (see FIG. 3) through machining. ), The size can be reduced while maintaining the strength and the ball joint portion 2 (see FIG. 3). Therefore, even when the inclined line P1c is formed on the side surface part 5f that is the farthest position from the arm part 6f in the interference area IF, the strength is maintained in consideration of the grain flow by providing the peripheral line P1b. This makes it possible to achieve downsizing. Of course, in the ball joint portion 2f, the parting line P1 serving as the peripheral line P1b is convenient at the position of the interference region IF. Therefore, the ball joint portion 2f can bring the joint center closer to the wheel center. In addition, when it is set as the structure which lengthens the arm part 6f by the part which the ball joint part 2f became small, reinforcement to the part which lengthened the arm part 6f is needed.

  Next, as shown in FIGS. 8A and 8B, the forging die 10 of the forged suspension arm 1f will be described. FIGS. 8A and 8B are schematic views showing a cross-sectional state of the ball joint portion in the forging die. The forged suspension member 1f is configured such that the parting line PL is different from the position of the tilt base point A1 in the parting line P1 in the state of FIG. In addition, the one end surface portion 3f of the ball joint portion 2f is inclined with respect to the upper surface of the arm portion 6f in a rising direction, and is joined to the right angle when viewed from the arm portion 6f side. As an example, a forging die 10 that achieves forging of the forged suspension member 1f will be described.

  As shown in FIG. 8 (a), in the forging die 10, the upper die 11 and the lower die 12 have a die split surface 13 along the parting line PL of the forged suspension member 1f. At this time, when the tilt base point A1 of the tilt line P1c is included in the interference area IF in the parting line P1 of the ball joint portion 2f, the tilt base point A1 is in a direction deviating from the range of the interference area IF, that is, As shown in FIG. 8B, the forging suspension member 1f is forged as the parting surface 13 in a state where the forging posture is inclined.

In this way, by adjusting the forging posture of the forged suspension member 1f by giving priority to the forging posture at the ball joint portion 2f of the forged suspension member 1f, the portion protruding from the side surface portion 5f is eliminated in the interference region IF, or Can be minimized. In addition, the joining attitude | position of the ball joint part 2f and the arm part 6f of the forge suspension member 1f may be set as various structures, and is not limited to what is shown in FIG. In addition, the forged suspension member 1f has a forged posture inclined in a direction away from the interference area IF by the inclination base point A1 or the inclination base point A2 (not shown), so that an inclination line P1c formed on the left and right sides of the interference area IF. Is shifted to the left and right from the center of the interference region IF, that is, the side surface portion 5f which is the farthest position from the arm portion 6f, so that the protruding portion in the interference region IF can be reduced.
Note that when adjusting the forging posture, there is a relationship with the posture of other parts, so there is a limit to the forging posture to be inclined, and the forging posture is adjusted within the limit.

  The forged suspension member 1f formed by the forging die (for example, the forging die 10) is then formed on the suspension arm 1 as shown in FIGS. 2 and 3 through machining such as trimming and cutting. The At this time, as shown in FIG. 3, in the interference region IF in the ball joint portion 2f of the forged suspension member 1f, when the parting line P1 is formed by the peripheral line P1b, it is cut off as a result, and the forging The shape of the side surface portion 5f of the suspension member 1f can be used almost as it is.

  As shown in FIG. 3, the suspension arm 1 is machined as shown by a solid line and formed in a state as shown in FIG. In the ball joint portion 2 of the suspension arm 1, the opening portion 4 a of the other end surface portion 4 penetrates from the opening portion 3 a of the one end surface portion 3, and the ball portion 34 of the ball stud bolt 33 is inserted into a plurality of parts. It is formed so that it can be engaged and supported via the interposition member 38. Further, the ball joint portion 2 is configured such that a step portion is formed slightly above the center of the side surface portion 5 to form a locking portion 5b, and a dust cover 37 is engaged with the locking portion 5b. .

Therefore, as shown in FIG. 1, since the burr surface is deleted at the time of machining at the position facing the wheel 30 side, a ball joint portion where a parting line PL is formed at the center in the past (see FIG. 10). In contrast, it is not necessary to consider the remaining burr length in the tire interference region, and the joint center of the ball joint portion 2 can be made closer to the wheel center accordingly. The cross-sectional shape of the arm portion 6 of the suspension arm 1 may be formed in a U shape or an H shape.
In the case of cutting, if the reference for trimming is the lower die, similarly, the cutting accuracy can be improved by using the lower die as a reference even during cutting. It becomes possible.

  Further, as shown in FIG. 2, the suspension arm 1 formed by a predetermined machining or the like from the forged suspension member 1 f forged with the above-described configuration has a spherical radius of the ball portion 34 of the ball stud bolt 33. The ball joint portion 2 is within a range in which R1 and the distance R2 from the center position of the ball portion 34 of the ball joint portion 2 to the outermost portion satisfy the ratio 1.2 <R2 / R1 ≦ 1.9. Is formed.

  This R2 / R1 is related to the degree of freedom and strength of design of the ball joint portion 2, and as R2 / R1 decreases (when the value of R1 increases), the degree of freedom of design increases, but the strength of the joint portion 2 increases. In particular, if it exceeds 1.9, the required strength cannot be obtained with certainty. Further, as R2 / R1 increases (when the value of R2 increases), the strength of the joint portion 2 increases, but the degree of freedom of design becomes narrower. Will be disturbed.

  And the drawing strength and the punching strength in the ball joint portion 2 configured as 1.2 <R2 / R1 ≦ 1.9 are set to be 25 kN or more here. If the pull-out strength and the punch-out strength of the ball joint part 2 are less than 25 kN, the ball part 34 may come off from the ball joint part 2 when running on the axle side. It is trying to become. In particular, by using the above-described high-strength aluminum alloy and by setting the parting line PL in the ball joint portion 2f to a predetermined position, the strength of the ball joint portion 2 after machining can be maintained and reduced in size. Can be done smoothly.

In the above-described embodiment, the tilt base points A1 and A2 in the peripheral line shape P1b of the parting line P1 are arranged so as to be outside the interference region IF as the best mode, and the conventional parting line is Compared with the one in the center, even if the inclined line P1c is arranged in the interference region IF, the strength can be maintained and the miniaturization can be achieved.
Even when the shape of the arm portion 6f, the shape of the ball joint portion 2f, the joint angle to the arm portion 6f, and the like are variously configured, the parting line P1 in the ball joint portion 2f is the peripheral line P1b and By forming the continuous line P1a, or the peripheral line P1b, the inclined line P1c, and the continuous line P1a, it is possible to reduce the sagging of the draft angle, and to maintain the strength and achieve the downsizing of the ball joint portion 2f. It can be done.

  Further, as shown in FIG. 3, as the suspension arm 1, the parting line PL has been described as having a configuration in which the arm portion 6 is arranged in the center in the thickness direction on the side surface, but the thickness on the upper end side or lower end side of the side surface is described. You may arrange | position as arbitrary positions in the range of a direction. Here, it forms so that it may become an upper end side and a lower end side, and is the periphery of the one end surface part 3, and the side part 5 used as the edge part far from the arm part 6 It is good also as a structure of the parting line PL1 and the parting line PL2 currently formed toward the position.

  In addition, about the case where it forges with the forge metal mold | die 10 shown in FIG. 8, as shown in FIG. 9, the burr outflow direction is changed from the state shown in FIG. 9 (a) to the state shown in FIG. 9 (b). It doesn't matter. That is, in FIG. 9A, the burr outflow direction Bf from the side surface portion 5f of the ball joint portion 2f is, for example, a horizontal direction that is a direction orthogonal to the forging press direction. On the other hand, in FIG. 9B, the position of the set parting line (not shown) is slightly changed without changing the forging posture. Bf is set to an inclination direction inclined by a predetermined angle from the horizontal direction to the perpendicular (forging press direction) side. Thus, by adjusting the burr outflow direction Bf in combination with the arrangement of the above-described parting line P1 (see FIGS. 3 to 7), the forged suspension member 1f is machined, particularly caulked. Thus, it is possible to provide the suspension arm 1 (see FIG. 2) that improves the moldability with respect to the caulking processing load and is effective in improving the punching strength.

It is sectional drawing which abbreviate | omitted one part which shows the attachment position of the suspension arm concerning this invention. It is a side view which shows the state which fractured | ruptured a part of suspension arm concerning this invention. It is sectional drawing which shows the cross-sectional state of the ball joint part of the suspension arm concerning this invention. (A)-(e) is a schematic diagram which shows the position of the parting line of the forge suspension member concerning this invention, (a) is a top view of the state inclined so that the interference area | region of a ball joint part could be seen , (B) is a left side view with respect to (a), (c) is a right side view with respect to (a), (d) is a front perspective view in which an arm portion from the front lower direction with respect to (a) is omitted, (E) is a perspective view schematically showing a parting line. (A), (b) is a top view which shows typically two types of the whole suspension arm concerning this invention as an example, respectively. (A) is the schematic diagram which shows typically the other structure of the parting line in the ball joint part of the forged suspension member concerning this invention as a front perspective view and a left-right side view, (b) is concerning this invention It is a schematic diagram which shows typically still another structure of the parting line in the ball joint part of a forged suspension member as a front perspective view and left and right side views. (A) is the schematic diagram which shows typically the other structure of the parting line in the ball joint part of the forged suspension member concerning this invention as a front perspective view and a left-right side view, (b) is concerning this invention It is a schematic diagram which shows typically still another structure of the parting line in the ball joint part of a forged suspension member as a front perspective view and left and right side views. BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic diagram which shows a part of forging die of the forged suspension member concerning this invention from a side surface, (a) is a schematic diagram before adjusting a forging attitude, (b) is after adjusting a forging attitude. FIG. (A), (b) is a schematic diagram which shows typically the state which changed the outflow method of the burr | flash in the forge suspension member concerning this invention. It is sectional drawing which shows the state which fractured | ruptured the ball joint part of the conventional forged suspension arm.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Suspension arm 1f Forged suspension member 2 Ball joint part 2f Ball joint part (forged suspension member)
3 One end surface portion 3f One end surface portion (forged suspension member)
4 other end surface portion 4f other end surface portion (forged suspension member)
5 Side surface portion 5f Side surface portion (forged suspension member)
6 Arm part 6f Arm part (forged suspension member)
DESCRIPTION OF SYMBOLS 10 Forging die 11 Upper die 12 Lower die 13 Split surface 30 Wheel 31 Axle 32 Support member 33 Ball stud bolt (stud bolt)
34 Ball part 35 Screw part 36 Body part 37 Dust cover 38 Interposition member SL Normal line GF Grain flow PL Parting line (whole)
P1 Parting line (ball joint part)
P1a continuous line (parting line)
P1b peripheral line (parting line)
P1c inclined line (parting line)
P2 Parting line (arm part)
R1 Spherical radius R2 Outermost SN from the center of the ball joint (in the direction of the ball stud bolt)

Claims (11)

To form a suspension arm having a ball joint portion that is pivotally mounted on a support member supported on the axle side of an automobile via a stud bolt and that is attached so as to avoid an interference area with respect to an axle side part by machining. Forged suspension members of
The forged suspension member includes an arm portion, a ball joint portion provided at one end of the arm portion, a vehicle body side engaging portion provided at the other end of the arm portion, the arm portion, the ball joint portion, and the vehicle body. A parting line formed continuously at a predetermined position of the side engagement portion,
The ball joint portion includes one end surface portion, the other end surface portion facing the one end surface portion, and a side surface portion formed over the other end surface portion and the one end surface portion.
The parting line of the ball joint portion is formed as a peripheral line along the periphery of either the one end surface portion or the other end surface portion at a position in the range that becomes the interference region in the side surface portion, and the interference region A forged suspension member, wherein the forged suspension member is formed so as to be continuous from both ends of the peripheral line to a parting line of the arm portion at a position in the side surface portion in a range from the outside to the arm portion. To form a suspension arm having a ball joint portion that is pivotally mounted on a support member supported on the axle side of an automobile via a stud bolt and that is attached so as to avoid an interference area with respect to an axle side part by machining. Forged suspension members of
The forged suspension member includes an arm portion, a ball joint portion provided at one end of the arm portion, a vehicle body side engaging portion provided at the other end of the arm portion, the arm portion, the ball joint portion, and the vehicle body. A parting line formed continuously at a predetermined position of the side engagement portion,
The ball joint portion includes one end surface portion, the other end surface portion facing the one end surface portion, and a side surface portion formed over the other end surface portion and the one end surface portion.
The parting line of the ball joint portion is formed as a peripheral line along the periphery of either the one end surface portion or the other end surface portion at the position in the side surface portion that is the farthest position from the arm portion, In the position in the side surface portion in the range from both ends of the line to the arm portion, an inclination that is inclined with respect to the perpendicular from both ends of the peripheral line to the other peripheral edge of the one end surface portion or the other end surface portion A forged suspension member formed as a line and formed as a continuous line continuous from a peripheral edge of either one of the one end face part or the other end face part to the parting line of the arm part. To form a suspension arm having a ball joint portion that is pivotally mounted on a support member supported on the axle side of an automobile via a stud bolt and that is attached so as to avoid an interference area with respect to an axle side part by machining. Forged suspension members of
The forged suspension member includes an arm portion, a ball joint portion provided at one end of the arm portion, a vehicle body side engaging portion provided at the other end of the arm portion, the arm portion, the ball joint portion, and the vehicle body. A parting line formed continuously at a predetermined position of the side engagement portion,
The ball joint portion includes one end surface portion, the other end surface portion facing the one end surface portion, and a side surface portion formed over the other end surface portion and the one end surface portion.
The parting line of the ball joint portion is formed as a peripheral line along the periphery of either the one end surface portion or the other end surface portion at the position in the side surface portion that is the farthest position from the arm portion, In the position on the side surface in the range from both ends of the line to the arm portion, it is inclined from either end of the peripheral line toward the other peripheral edge of the one end surface portion or the other end surface portion and with respect to the vertical line A forged suspension member, wherein the forged suspension member is formed as a continuous line that is formed as an inclined line and continues from a portion beyond the position to be the interference region to a parting line of the arm portion.   4. The forged suspension member according to claim 2, wherein at least one of the inclined base points at both ends of the peripheral line of the parting line in the ball joint portion is disposed outside the interference region. . To form a suspension arm having a ball joint portion that is pivotally mounted on a support member supported on the axle side of an automobile via a stud bolt and that is attached so as to avoid an interference area with respect to an axle side part by machining. Forged suspension members of
The forged suspension member includes an arm portion, a ball joint portion provided at one end of the arm portion, a vehicle body side engaging portion provided at the other end of the arm portion, the arm portion, the ball joint portion, and the vehicle body. A parting line formed continuously at a predetermined position of the side engagement portion,
The ball joint portion includes one end surface portion, the other end surface portion facing the one end surface portion, and a side surface portion formed over the other end surface portion and the one end surface portion.
The parting line in the side surface portion of the ball joint portion includes an inclined line that is inclined with respect to a normal line from the periphery of the one end surface portion to the periphery of the other end surface portion, and the peripheral edge of the one end surface portion from the inclination base point of the inclined line. A peripheral line along the peripheral edge of the other end surface part and a continuous line continuing from the peripheral line to the parting line of the arm part, and at least one of the inclined base points that are both ends of the inclined line is the A forged suspension member formed at a position in an interference region. To form a suspension arm having a ball joint portion that is pivotally mounted on a support member supported on the axle side of an automobile via a stud bolt and that is attached so as to avoid an interference area with respect to an axle side part by machining. Forged suspension members of
The forged suspension member includes an arm portion, a ball joint portion provided at one end of the arm portion, a vehicle body side engaging portion provided at the other end of the arm portion, the arm portion, the ball joint portion, and the vehicle body. A parting line formed continuously at a predetermined position of the side engagement portion,
The ball joint portion includes one end surface portion, the other end surface portion facing the one end surface portion, and a side surface portion formed over the other end surface portion and the one end surface portion.
The parting line in the side surface portion of the ball joint portion includes an inclined line that is inclined with respect to a normal line from the periphery of the one end surface portion to the periphery of the other end surface portion, and the peripheral edge of the one end surface portion from the inclination base point of the inclined line. An inclined base point that is formed on a peripheral line along the peripheral edge of the other end surface part and a continuous line that extends from the peripheral line to the parting line of the arm part, and whose both ends of the inclined line are outside the interference region. A forged suspension member formed at a position to be   The forged suspension member according to any one of claims 1 to 6, wherein a peripheral line in a parting line of the ball joint portion is disposed at a position to be removed by machining. In the suspension arm formed by machining the forged suspension member according to any one of claims 1 to 7,
When the radius of the ball ball diameter of the stud bolt engaged with the ball joint part of the suspension arm is R1, and the distance from the center of the ball joint part to the outermost part in the interference region of the ball joint part is a distance R2, 1.2 <R2 / R1 ≦ 1.9 A suspension arm, wherein the ball joint portion is formed at a ratio of 1.9.   The suspension arm according to claim 8, wherein the pull-out strength and the punch-out strength of the stud bolt are 25 kN or more.   9. The forged suspension member is made of an Al—Mg—Si based aluminum alloy having an average area ratio of sub-crystal grains in the structure of 60% or more and a 0.2% proof stress of 290 MPa or more. The suspension arm according to claim 9. A forging die used for the forged suspension member according to any one of claims 1 to 5 and claim 7,
The forging die of the forging suspension member is characterized in that forging is performed in a state where an inclination base point corresponding to an inclined line-shaped parting line of the ball joint portion is inclined in a direction away from the interference region.

Images