JP6264652B2 - Automotive knuckle - Google Patents

Description

  The present invention relates to an automobile knuckle, and particularly relates to an automobile knuckle to which a light alloy is applied for weight reduction.

  The invention related to the above technical field is disclosed in Patent Document 1 below. The knuckle for automobiles disclosed in Patent Document 1 is “for automobiles characterized in that a bearing bush made of a material different from a base material is formed by insert molding on a bearing support part for supporting a bearing for rotating and supporting a wheel. "Knuckle". Specifically, for weight reduction, “the base material is made of aluminum or an alloy thereof”, and the bearing bush into which the bearing is press-fitted and mounted is “cast iron, steel material, stainless steel, titanium alloy, or fiber” It is made of a material that is stronger than the base material such as reinforced metal.

JP 2006-51507 A

  The knuckle for automobiles of Patent Document 1 described above is made of a steel material having a higher strength than the base material because the base material (the base body in the present application) is made of aluminum or the like, so that the weight of the automobile knuckle is reduced. Since the bearing bush (the bearing mounting portion in the present application) is insert-molded, the bearing can be supported. However, as a result of intensive studies by the inventors of the present application, in the automobile knuckle of Patent Document 1, moisture brought from the outside due to the base metal and the bearing bush being made of different metals, ) When intervening at the interface, contact corrosion of dissimilar metals based on the difference in ionization tendency between the two (generally referred to as electrochemical corrosion, that is, a corrosion phenomenon called electrolytic corrosion. Hereinafter, this corrosion is referred to as electrolytic corrosion) As a result, it has been found that there is a possibility that the knuckle for automobiles may be damaged by the stress acting on the traveling.

  The present invention is an invention made by the inventors of the present invention eagerly examining the problems of the prior art, in which a base made of a light alloy and a hole provided in the base for mounting a bearing are formed. An object of the present invention is to provide an automotive knuckle having a structure capable of suppressing the occurrence of electrolytic corrosion even when the base and the bearing mounting part are made of different metals. Yes.

  One form of the present invention for achieving the above object is an automobile knuckle having a base made of a light alloy and a bearing mounting portion provided in the base and having a hole for mounting a bearing. The bearing mounting portion is made of a metal different from the base, and the length of the hole portion in the direction along the central axis of the hole portion is smaller than the length of the bearing. It is a knuckle for automobiles.

  In the knuckle for automobiles of the above form, it is preferable that the bearing mounting portion is surrounded by the base body and fixed to the base body except for an inner peripheral surface of the hole.

  Further, the hole is disposed on one side of the hole in the direction along the central axis, and has one opening for inserting the bearing, and the other opening disposed on the other side of the one opening. It is preferable that the base has a protruding portion that protrudes inward and is disposed outside the other opening of the hole.

  According to the above-described automotive knuckle according to the present invention, the automotive knuckle is configured to suppress the occurrence of electrolytic corrosion even when the base and the bearing mounting portion are made of different metals. Can be provided.

It is the front view and sectional drawing of the knuckle for motor vehicles of 1st Embodiment which concern on this invention. It is the A section enlarged view of FIG. It is a partial expanded sectional view of the knuckle of the modification of the knuckle for motor vehicles of FIG. It is a partial expanded sectional view of the knuckle for motor vehicles of 2nd Embodiment which concerns on this invention. It is a front view which shows the partial cross section of the knuckle for motor vehicles of 3rd Embodiment which concerns on this invention. It is sectional drawing of the metal mold | die for demonstrating the manufacturing method of the knuckle for motor vehicles of 1st Embodiment shown in FIG. It is the D section enlarged view of FIG. It is a figure for demonstrating the manufacturing method of the knuckle for motor vehicles of 2nd Embodiment shown in FIG.

  Hereinafter, the present invention will be described based on the embodiment with reference to the drawings. It should be noted that the present invention is not limited to the specific embodiments, and the constituent elements of each embodiment are not limited to the embodiments, and are appropriately selected within the scope of the operations and effects of the present invention. It can be implemented in combination.

  As shown in FIGS. 1 to 5, the knuckle for automobiles 10 to 40 of each embodiment according to the present invention is provided on the base 11 made of a light alloy as a configuration common to all the embodiments, and the base 11. And a bearing mounting portion 18 (48) in which a hole 12 to which the bearing 90 is mounted is formed. And the bearing mounting part 18 (48) is comprised with the metal different from the base | substrate 11, and the direction (henceforth this direction is called a central-axis direction) along the central axis H of the hole 12 may be called. The direction perpendicular to the central axis H may be referred to as the radial direction, and the direction around the central axis H may be referred to as the circumferential direction.) The length L1 of the hole 12 in the bearing 90 is smaller than the length L2 of the bearing 90. It is a feature.

  According to the knuckle for automobiles 10 to 40 having such a configuration, the bearing mounting portion 18 (48) made of a metal different from the base body 11 is provided on the base body 11, and as shown in FIGS. Have bonding (contact) interfaces 18e and 18f. Here, the length L1 of the hole 12 in the central axis direction is configured to be smaller than the length L2 of the bearing mounted in the hole 12. As a result, when the bearing 90 is mounted in the hole portion 12, the joint (contact) interfaces 18 e and 18 f between the base body 11 and the bearing mounting portion 18 (48) are in contact with the outer peripheral surface of the bearing 90. For this reason, since the joint (contact) interfaces 18e and 18f are almost covered by the outer peripheral surface of the bearing 90, it is difficult for moisture in the outside world to reach the joint (contact) interfaces 18e and 18f, thereby suppressing electrolytic corrosion. It becomes possible to do. In order to further suppress the intrusion of moisture, if a sealant G is applied between the bearing mounting portion 18 (48) and the bearing 90 or a seal member is interposed, the effect of suppressing electrolytic corrosion increases. preferable.

  Hereinafter, the knuckle for automobiles of the above-described form (hereinafter may be simply referred to as a knuckle) will be specifically described based on first to third embodiments which are specific examples thereof.

[First Embodiment]
The knuckle of the first embodiment will be described with reference to FIGS. 1A is a front view seen from the wheel side of the knuckle of the first embodiment, and FIG. 1B is a cross-sectional view taken along the line C-C in FIG. FIG. 2 is an enlarged view of a portion A in FIG.

  As shown in FIG. 1, the knuckle 10 of the present embodiment includes a base body 11 and a bearing mounting portion 18 provided on the base body 11. Hereinafter, each structure of the base | substrate 11 and the bearing mounting part 18 is demonstrated.

  The base body 11 has a cylindrical portion 13 and a plurality of arms 14, 15, 16, 17-1, 17-2 extending radially from the cylindrical portion 13, and the bearing mounting portion 18 is an inner part of the cylindrical portion 13. It is arranged on the circumference. The arm 14 is a strut mounting arm that is provided so as to bend inside the vehicle and connects the suspension strut to the mounting portion. A lower arm mounting arm 15 is formed on the side opposite to the arm 14 with respect to the cylindrical portion 13. A knuckle arm 16 protrudes from the cylindrical portion 13 between the arm 14 and the arm 15, and a ball stud (not shown) is attached to a tapered hole 16 d formed at the tip of the knuckle arm 16. An end portion of a steering rod for steering is connected to the ball stud. In addition, it is preferable to provide a hollow part in the arms 14 to 17-2 because the knuckle 10 can be further reduced in weight.

  As the light alloy constituting the base 11, for example, a light alloy mainly composed of Al (aluminum), Mg (magnesium), or the like can be used. Specifically, it is preferable that the substrate 11 is made of JIS-AC4A, AC4C, or AC4CH, which is an Al—Si—Mg alloy.

  As shown in FIG. 2, the cylindrical, more specifically, substantially cylindrical bearing mounting portion 18 has a hole 12 in which a bearing 90 is mounted. The hole 12 is press-fitted (inserted) from the direction of the arrow B so that the outer peripheral surface of a bearing 90 such as a ball bearing or a bearing unit is in contact with the inner peripheral surface 18a. A wheel shaft portion is inserted into and held by the fixed bearing 90. Note that the shape of the bearing mounting portion 18 is not limited to this embodiment, and may be any shape as long as a desired bearing 90 can be mounted. Another example will be described in detail in a third embodiment to be described later.

  Although the form of arrangement of the bearing mounting portion 18 on the base 11 is not particularly limited, in order to securely hold the bearing mounting portion 18 on the base 11, as shown in FIG. It is desirable that the outer peripheral surface 18a of the twelve is surrounded by the base 11 and fixed to the base 11. That is, the base 11 is configured to contact the outer peripheral surface 18b, the upper surface 18c, and the bottom surface 18d of the cylindrical bearing mounting portion 18, and more preferably all surfaces except for the inner peripheral surface 18a to which the bearing 90 is mounted. It is desirable to do. Thereby, for example, even when a load at the time of press-fitting the bearing 90 or a load at the time of travel is applied, the bearing mounting portion 18 is prevented from being detached from the base body 11, and the bearing mounting portion due to the difference in thermal expansion from the base body 11 is prevented. It is possible to prevent 18 rotations. In addition, from the surface for preventing separation and rotation prevention, any one of the outer peripheral surface 18b, the upper surface 18c, and the bottom surface 18d of the bearing mounting portion 18 may be roughened, or unevenness may be provided on any surface.

  Further, as in a knuckle 30 shown in FIG. 3 which is a modification of the knuckle of FIGS. 1 and 2, the inner diameter of the inner peripheral surface 18a of the bearing mounting portion 18 is larger than the inner diameter of the inner peripheral surface 11b of the cylindrical portion (base body) 13. And a step in the radial direction may be formed between the two. In this case, since a gap 31 is formed between the inner peripheral surface 11b of the cylindrical portion 13 and the outer peripheral surface of the bearing 90, the sealing agent G and the sealing member described above are used so that moisture does not enter from the gap 31. Just place it. However, from the surface for preventing electrolytic corrosion, as shown in FIG. 2, the inner diameter of the inner peripheral surface 18a of the bearing mounting portion 18 and the inner diameter of the inner peripheral surface 11b of the cylindrical portion 13 are substantially the same. It is advantageous from the viewpoint of suppressing moisture intrusion that there is almost no step in the radial direction.

  As the metal material constituting the bearing mounting portion 18, a material that has higher strength than the base 11 and can withstand a load that acts during press-fitting or running of the bearing 90 can be used. For example, cast iron, steel, stainless steel, titanium alloy, or The bearin mounting portion 18 can be formed of a fiber reinforced metal or other various metal materials.

  Here, the hole 12 of the present embodiment has an upper (one) opening 18g that is disposed on the upper (one) side of the hole 12 in the central axis direction and into which the bearing 90 is inserted, and an upper opening 18g. And the lower (other) opening 18h arranged on the lower (other) side. In the present embodiment, which is a preferred example, the cylindrical portion (base body) 13 is disposed on the lower (outside) side of the lower opening 18h of the hole 12 and protrudes inward in the radial direction. 11a is formed. Specifically, in the radial direction, the protrusion 11 a is formed to protrude beyond the inner peripheral surface 18 a of the hole 12.

  The protruding portion 11a provided on the cylindrical portion (base body) 13 is in contact with the bottom surface of the bearing 90 inserted from the upper (one) opening 18g with the upper surface thereof, thereby positioning the bearing 90 in the central axis direction and Has the function of receiving a thrust load. Here, the protrusion 11a may be provided on the bearing mounting portion 18. However, since the bearing mounting portion 18 is high in strength and has poor workability and high cost, the protrusion 11a is provided on the bearing mounting portion 18. This is not preferable for industrial production. On the other hand, since the projection part 11a of this form is provided in the cylinder part (base | substrate) 13 comprised with the light alloy, workability is good and it is preferable on industrial production in terms of cost. It should be noted that the lower surface 18d of the bearing mounting portion 18 and the upper surface of the protruding portion 11a may be arranged in contact with each other in the central axis direction. However, from the viewpoint of suppressing moisture intrusion, it is desirable that the two are separated from each other as shown. Further, as shown in FIG. 1, the protrusions 11 a of the present embodiment are formed to have a substantially annular shape, but are not limited thereto, and may be, for example, elliptical, equally spaced or unequal in the circumferential direction. It is good also as a projection part by arrange | positioning a convex part to a space | interval.

  The cylindrical portion 13 and the bearing mounting portion 18 may be fitted or engaged with a locking member such as a seal member or a snap ring for dust prevention or lubricating oil retention.

[Second Embodiment]
A knuckle according to a second embodiment of the present invention will be described with reference to FIG. 4 which is an enlarged cross-sectional view of a cylindrical portion displayed in the same manner as FIG. In FIG. 4, the same components as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted (the same applies to the third embodiment).

  As shown in FIG. 4, the knuckle 20 of the second embodiment is basically configured in the same manner as the knuckle of the first embodiment. 1 differs in that the protrusion 21a is disposed above. That is, the knuckle 20 of the present embodiment is different from the first embodiment in that the bearing 90 is inserted from the lower (one) opening 28g arranged on the lower (one) side of the hole 12 in the central axis direction. The loading direction of the bearing 90 is reversed. For this reason, the protruding portion 21a of the base body 21 is disposed so as to protrude inwardly on the upper (outside) side of the upper (other) opening 28h disposed on the upper side (the other side) of the lower opening. .

  Thus, even in the knuckle 20 in which the protruding portion 21a is disposed above, the upper surface of the bearing 90 inserted from the lower (one) opening 28g contacts the bottom surface of the protruding portion 21a, whereby the first embodiment described above. Like the knuckle, the positioning of the bearing 90 in the central axis direction and the thrust load can be received. Further, in the knuckle 20 of the present embodiment, the protrusion 21a is disposed upside down with respect to the protrusion 11a of the first embodiment, as described in the manufacturing method described below, so that the knuckle that is the product is cast. It is possible to reduce the amount of surplus added to the intermediate body in both the base body and the bearing mounting portion, and it is possible to manufacture the knuckle at a low cost.

[Third Embodiment]
A knuckle according to a third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a front view of the knuckle of the third embodiment, and the cylindrical portion 13 is a sectional view.

  As shown in FIG. 5, the knuckle 40 of the third embodiment is basically configured in the same manner as the knuckle of the first embodiment, but includes a plurality of segment-like support pieces 48 a to 48 d (in the case of this embodiment). 4), the bearing mounting portion 48 is configured in combination. That is, the cross-sections of the individual support pieces 48a to 48d in the radial direction have an arch shape, and the inner circumferential surface formed so as to have substantially the same curvature is in a posture facing inward, so that a constant interval is provided in the circumferential direction. It is arranged at an equal pitch (angle) while opening. Accordingly, the inner peripheral surfaces of the four support pieces 48a to 48d cooperate to form the hole 12 in which the bearing is mounted. In addition, the light alloy which comprises the cylinder part (base | substrate) 13 is interposing between each support piece 48a-48d. According to the knuckle 40 having such a configuration, the weight of the bearing mounting portion 48 made of a material having a specific gravity larger than that of the light alloy constituting the base body 11 can be reduced, and the knuckle 40 can be further reduced in weight. Become.

  As a method for manufacturing the knuckle, the material of the bearing mounting portion is arranged at a predetermined position in the cavity of the mold that is shaped like the base, and a molten metal that melts the light alloy constituting the base is poured into the cavity. There is a manufacturing method for casting a bearing mounting material. Hereinafter, an example of a manufacturing method for manufacturing the knuckle of the first embodiment using the low pressure casting method will be described with reference to FIGS. Here, FIG. 6 is a cross-sectional view of a mold (mold) used in the manufacturing method of this example, and FIG. 7 is an enlarged view of a portion D in FIG.

  As shown in FIG. 6, the mold 50 used in this example for manufacturing the knuckle of the first embodiment is composed of an upper mold 50a and a lower mold 50b, and the upper mold 50a and the lower mold 50b are matched. As a result, a cavity is formed. Here, the shape of the cavity of the mold 50 is such that an intermediate 50c having a shape in which a surplus or the like set as necessary is added to the knuckle 10 (see FIG. 1) as the final product is formed. It has been. That is, the cavity of the mold 50 is formed such that a portion 50e corresponding to the arms 14 to 17-2 and the like and a portion 50d corresponding to the cylindrical portion 13 are formed in the intermediate 50c. The lower mold 50b is formed with a runner 10f disposed so as to communicate with the cavity, and the molten metal is supplied to the cavity as indicated by an arrow F through the runner 10f.

  Here, in the manufacturing method of this example, since the bearing mounting portion material is arranged at a predetermined position in the cavity, as shown in FIG. 7, the bearing formed of a desired material on the upper mold 50a of the mold 50 described above. The mounting portion material 58 is fixed. Specifically, a convex part 50g extending downward is provided in the upper mold 50a, and a substantially cylindrical bearing mounting part material 58 is passed through the convex part 50g and fixed to the convex part 50g. Here, the method of fixing the bearing mounting portion material 58 is not particularly limited, but the convex portion 50g is formed into a substantially truncated cone shape, and the inner peripheral surface of the bearing mounting portion material 58 is matched to the inclination angle α of the outer peripheral surface of the convex portion 50g. It is preferable to be inclined. As a result, the centering of the two becomes easy, and the bearing mounting portion material 58 is pressed and fixed to the convex portion 50g by the force acting in the direction of arrow E along with the elastic deformation caused by the pressing of the bearing mounting portion material 58. The

  The method for fixing the bearing mounting portion material 58 to the convex portion (mold) 50g is not limited to the above, and for example, a method is provided in which a magnetic circuit is provided in the convex portion 50g and the magnetic circuit generates the magnetic circuit. The convex portion 50g is provided with a flow path that opens to the outer peripheral surface thereof, and a pressure reducing device is connected to the flow path, and the pressure is reduced and fixed, or a resin that is decomposed and gasified with a high-temperature molten metal. A fixing method, a fixing method via a core, and other various fixing methods can be used.

  As described above, the molten metal is poured into the cavity in which the bearing mounting portion material 58 is disposed, and the intermediate body 50c in which the bearing mounting portion material 58 is cast in the cylindrical portion 50d is formed. Then, the knuckle 10 which is a final product having the base body 11, the bearing mounting portion 18, and preferably the projection portion 11a, shown by a two-dot chain line in FIG. Can be obtained. In addition, a surplus is not provided for near net shape, but the molten metal may be poured into a cavity that is roughly shaped in the shape of the final product, and the knuckle may be manufactured without basically processing the intermediate. However, even in this case, it is desirable to at least process the inner peripheral surface of the bearing mounting portion on which the bearing is mounted to adjust the dimensional accuracy and surface roughness.

  Next, the manufacturing method of the knuckle of 2nd Embodiment is demonstrated, referring FIG. FIG. 8 is a partially enlarged cross-sectional view of a mold 60 used for manufacturing the knuckle of the second embodiment, which is displayed in the same manner as FIG.

  The manufacturing method of this example is basically the same as the manufacturing method of the knuckle of the first embodiment, but the protrusion 21a of the second embodiment is provided below, and the first embodiment provided above. This is due to the fact that it is provided at a position opposite to the protruding portion 11a of the embodiment, and is different particularly in that the mold 60 includes the bearing mounting portion material 68 and the surplus thickness of the cylindrical portion 60d is reduced. . That is, as described above, the convex portion 50g of the upper mold 50a to which the bearing mounting portion material 68 is fixed has a substantially truncated cone shape, and its outer peripheral surface is an inclined surface. For this reason, even if the inclination angle α of the convex portion 50g is the same, when the protruding portion 11a is provided on the upper side as in the first embodiment, the amount of extra space is inevitably required to form the protruding portion 11a. Will increase. On the other hand, since the protrusion part 21a of 2nd Embodiment is provided below, the amount of surplus can be suppressed compared with the metal mold | die of 1st Embodiment.

10-40 Automotive knuckle 11 (21) Base 11a (21a) Projection 12 Hole 13 Tube 13a Inner circumferential surface 14 (15-17-2) Arm 18 (48) Bearing mounting 18a Bearing mounting Inner peripheral surface 18e (18f) Joint (contact) interface between the bearing mounting portion and the base 18g (28g) One opening 18h (28H) The other opening 50 (60) Mold (mold)
50a Upper mold 50b Lower mold 50c Intermediate 50d Part corresponding to the cylindrical part of the intermediate 50e Part corresponding to the arm of the intermediate 58 (68) Bearing mounting part material 90 Bearing

Claims (3)

  An automobile knuckle having a base made of light alloy and a bearing mounting portion provided in the base and having a hole for mounting a bearing, wherein the bearing mounting portion is made of a metal different from the base. A knuckle for an automobile, characterized in that the length of the hole in the direction along the central axis of the hole is smaller than the length of the bearing.   The knuckle for an automobile according to claim 1, wherein the bearing mounting portion is surrounded by the base body and fixed to the base body except for an inner peripheral surface of the hole.   The hole has, in a direction along its central axis, one opening that is disposed on one side of the hole and into which the bearing is inserted, and the other opening that is disposed on the other side of the one opening. The vehicle base knuckle according to claim 1, wherein the base body has a protruding portion that protrudes inward and is disposed outside the other opening of the hole portion.

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