JP4923302B2 - Upper mount - Google Patents

Description

  The present invention belongs to the technical field of the structure of an upper mount in which the upper end of a shock absorber is attached to the vehicle body side in an automobile suspension device.

  Conventionally, this type of suspension / upper mount has been widely used for the wishbone type and trailing arm type suspension, and the input separation type that receives the input from the shock absorber separately from the input from the coil spring is widely used. It has been. Such an upper mount usually has a rubber elastic body, and the elastic deformation of the upper mount reduces the impact and vibration on the vehicle body.

  For example, in paragraphs 0002 to 0004 of Patent Document 1 and FIG. 5 of the drawings, an outer metal fitting (outer metal fitting) fastened to a vehicle body panel is an iron plate press-molded product, and an inner metal fitting (inner (Metal fitting) and a rubber bullet body are housed and covered with a lid member that is also a press-molded product of an iron plate. By superimposing, it is easy to ensure rigidity even for press-molded products.

  Patent Document 2 describes an example of an upper mount used for a strut type suspension. In this case, in order to increase the rigidity of a mounting bracket (outer metal fitting) fastened to a vehicle body panel, press molding is performed. Sometimes the peripheral edge is bent downward over the entire circumference to form a rib.

Further, in Patent Document 1 and Patent Document 3, an upper mount that uses an aluminum alloy casting for the outer metal fitting instead of the above-described press-formed product of an iron plate and is lightened is also described.
JP 2002-274137 A Japanese Patent No. 3753066 JP 2007-170478 A

  By the way, in recent years, the adoption of flat tires has progressed in small cars and light cars, and there is a tendency for the unsprung load to increase as the wheel diameter increases, and the upper mount is also required to further increase its support rigidity. Yes. On the other hand, there is a growing demand for weight reduction of the entire automobile parts due to the heightened environmental awareness, and there is a persistent demand for cost reduction.

  In this regard, in the former conventional example in which the outer metal fitting is a press-molded product of an iron plate, the rigidity of the flange portion fastened to the vehicle body panel tends to be insufficient, and it cannot be said that a double structure in which lid members are overlapped is sufficient. . In addition, the double structure not only hinders weight reduction, but also increases the number of parts and the number of assembly steps, which is disadvantageous in terms of cost.

  On the other hand, if an aluminum alloy casting is used as in the latter conventional example, both securing rigidity and weight reduction can be achieved, but aluminum alloy is more expensive than iron-based materials. Since a special mold is required for each type, it is inevitable that the cost will be high.

  In addition, there is concern about electrolytic corrosion when mounting aluminum alloy parts to automobile body panels, which are generally made of iron-based materials, and reliability is high for high cost, considering the occurrence of nests in castings. It can be said that anxiety remains.

  In view of these points, an object of the present invention is to provide an upper mount that has high support rigidity, is excellent in reliability, and can be reduced in weight and cost.

  In order to achieve the above object, in the upper mount of the present invention, as in the former conventional example, the outer metal fitting is made of an iron-based material, and the side plate portion is integrally formed on the flange portion, and this is attached to the metal fitting. It is welded to the outer periphery of the main body to greatly increase the support rigidity.

  Specifically, the invention of claim 1 is directed to an upper mount for attaching an upper end of a shock absorber to a vehicle body side via an elastic body in an automobile suspension device, and an inner bracket fixed to the upper end of the shock absorber; An outer metal fitting connected to the inner metal fitting by the elastic body and fastened to the vehicle body panel. The outer metal fitting is a plate with a bottomed cylindrical shape that opens upward and a side wall that is disposed so as to surround the inner metal fitting, and a plate shape that extends from the upper edge toward the fastening portion of the vehicle body. The flange portion is integrally formed with an iron-based plate material together with a pair of side plate portions that are bent from the left and right side edges as seen in the extending direction and hangs down, and then, The inner peripheral side edge of each side plate portion is welded to the outer peripheral surface of the side wall of the main body portion of the outer metal fitting.

  Since the upper mount having such a configuration constitutes an outer metal fitting by forming an iron-based plate material, the cost can be reduced as compared with that of an aluminum alloy even if the labor of welding is taken into consideration. In addition, the problem of electrolytic corrosion and nests unlike those made of an aluminum alloy cannot occur, and the reliability is excellent.

  In addition, the flange part fastened to the vehicle body panel is provided with a side plate part so as to hang from both side edges, and this is welded to the side wall of the main body part, so the rigidity in the vertical direction becomes very high, High support rigidity can be obtained even in comparison with a double structure in which lid members are stacked. In addition, the weight can be reduced compared to the double structure, and the number of parts and the number of assembly steps can be reduced.

  Furthermore, when the outer metal fitting has a cylindrical stopper mounting portion that opens downward, and the ceiling portion is superimposed on the bottom of the main body portion from below, the outer peripheral surface of the side wall of the stopper mounting portion In addition, by welding the inner peripheral side edge of each side plate portion (Claim 2), higher support rigidity can be obtained.

  It is preferable that the main body portion of the outer metal fitting is also integrally formed with the flange portion and the side plate portion by an iron-based plate material (Claim 3), and in this way, the number of parts of the outer metal fitting and the welding location can be reduced. Further cost reduction is achieved.

  On the other hand, the main body part and the flange part may be molded separately and then assembled by welding, and in this way, parts can be shared for multiple types of upper mounts with different fastening sites, Cost reduction by mass production effect becomes possible.

  Preferably, a step is formed on the upper surface of the flange portion of the outer metal fitting so that the fastening portion with the vehicle body side is one step higher than the upper edge of the side wall of the main body, and the shape of the step is the flange portion in plan view. It is made into the shape of a "<" shape which approaches the said fastening site | part gradually toward the center from the both-sides edge (Claim 4). In this way, the bending rigidity of the flange portion can be increased, and the support rigidity of the upper mount can be secured more easily.

  Further, it is preferable to form a through hole so as to be opposed to each other on both side wall portions that form a pair for each flange portion of the outer metal fitting in order to assemble the upper mount to the shock absorber.

  That is, in general, it is desirable that the upper mount is transported in an assembly state assembled to a shock absorber, and when it is assembled to the vehicle body, it is desirable that the shock absorber is slightly pre-compressed. In the case where the portion is provided, if the through-hole is formed in the portion so that the string-like bundling member can be passed therethrough, the bundling member can be wound around the shock absorber and kept in a pre-compressed state.

  As described above, according to the upper mount according to the present invention, the outer metal fitting is made of an iron-based material, and the side plate portions hanging downward are provided on both side edges of the flange portion fastened to the vehicle body side. By welding to the outer surface of the main body, a sufficiently high support rigidity can be ensured while being relatively light and low in cost, and excellent in reliability. In particular, if all of the main body portion, the flange portion, and the side plate portions of the outer metal fitting are integrally formed, a structure that is advantageous for cost reduction can be obtained.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the following description of preferable embodiment is only an illustration essentially, and is not intending restrict | limiting this invention, its application thing, or its use.

  FIG. 1 shows an embodiment in which an upper mount according to the present invention is applied to a trailing arm suspension of an automobile. Although only the front side is shown in the figure, the upper mount M is near the rear end of the trailing arm A. The upper end of the shock absorber S that is attached to and extends upward is used to attach to the vehicle body panel (not shown). The example shown in the figure is a so-called torsion beam axle type in which a coil spring C and a shock absorber S are attached to a pair of left and right trailing arms A and A, respectively, and are connected by a torsion beam B. This is just an example.

  The upper mount M of this embodiment is shown in FIG. 2 and FIG. 3 (sectional view taken along the line III-III in FIG. 2), as shown in the rod R of the shock absorber S (shown in phantom only in FIG. 3). An inner bracket 1 (inner metal fitting) fixed to the upper end, and an outer bracket 3 (outer metal fitting) coupled to the inner bracket 1 by a rubber elastic body 2 and fastened to a vehicle body panel (not shown) are provided. Yes.

  The inner bracket 1 is made of a disc-shaped steel plate having a round hole 1a in the center, and a male screw portion r1 at the upper end of the rod R of the shock absorber S is inserted into the round hole 1a from below and is fastened by a nut (not shown). Is done. Further, the rubber bullet body 2 is vulcanized and integrally formed in a donut shape surrounding the entire outer periphery of the inner bracket 1, and in the example shown in the figure, annular groove portions 2 a and 2 a are provided on both upper and lower surfaces, and the shock absorber S Both top end positioning and shock and vibration absorption performance are achieved.

  On the other hand, the outer bracket 3 is composed of an upper member 4 and a lower member 5 each formed by molding an iron-based thin plate material, which are joined by welding. In the example shown in the drawing, a flat bottomed cylindrical main body portion 40 is formed by drawing a plate material on the upper member 4, and a ceiling portion of the cylindrical lower member 5 is formed on the bottom portion of the main body portion 40. Overlaid from below. Round holes 40a and 5a having larger diameters are opened and fitted in the bottom portion of the main body portion 40 and the ceiling portion of the lower member 5 so that the rod R of the shock absorber S is inserted therethrough.

  Further, the side wall of the main body portion 40 of the upper member 4 has a cylindrical shape having an inner diameter that is substantially the same as the outer diameter of the rubber bullet body 2, and radially outward from a portion facing the diameter direction at the upper edge thereof. A pair of flange portions 41, 41 are formed so as to extend. Each of these flange portions 41 has a tapered trapezoidal plate shape, and a round hole 41a (fastening portion: hereinafter, bolt) into which a fastening bolt to the vehicle body panel is inserted is located near the tip, that is, near the outer periphery. Called a hole).

  A pair of side plate portions 42 and 42 are integrally formed on the flange portion 41 so as to be curved and hang down from the left and right side edges when viewed in the extending direction. In the illustrated example, each side plate portion 42 has a bowl shape in which the inner peripheral side edge close to the main body portion 40 is longest in the vertical direction, and the height dimension gradually decreases from there toward the outer peripheral side. That is, the lower edge of the side plate portion 42 gradually rises on the way from the inner peripheral side edge to the outer peripheral side, and then has a substantially constant height in the vicinity of the bolt hole 41a. It is determined in consideration of the interference with the tool at the time of assembly.

  The inner peripheral side edges of the side wall portions 42, 42 provided for each flange portion 41 are welded to the outer peripheral surface of the side wall of the main body portion 40 of the upper member 4 at the upper part (EW1 in FIG. 2). The lower part of the lower member 5 is also welded to the outer peripheral surface of the side wall of the lower member 5 (shown as EW2), so that the vertical load acting on the flange portion 41 is firmly received. This is advantageous also in strengthening the coupling between the upper member 4 and the lower member 5 and increasing the rigidity of the outer bracket 3 as a whole.

  Further, a step 41 b is formed on the upper surface of the flange portion 41 so that a portion where a bolt hole 41 a fastened to the vehicle body panel opens is one step higher than the upper edge of the side wall of the main body portion 40. The step 41b is formed in a "<" shape in a portion near the inner periphery of the flange portion 41 connected to the main body portion 40 and gradually approaches the bolt hole 41a from both sides of the flange portion 41 toward the center in plan view. It functions as a reinforcing rib that increases the rigidity of the flange portion 41.

  That is, by providing such a step 41b, the bending rigidity of the flange portion 41 is effectively increased from the inner peripheral side edge connected to the main body portion 40 to the vicinity of the bolt hole 41a near the outer periphery. In addition to the effect of the side wall portion 42 described above, the support rigidity of the outer bracket 3 is further increased. FIG. 4 is a graph of experimental results obtained by measuring the static spring characteristics of the upper mount M of this embodiment in the vertical direction (in the direction of the axis Z in FIGS. 2 and 3), compared to the conventional type shown by the one-dot chain line. It can be seen that the rigidity is remarkably increased by providing the side wall portion 42 (shown by a broken line in the figure), and the rigidity is also increased by providing the flange portion 41 with a step 41b (shown by a solid line in the figure).

  In this embodiment, the upper member 4 is formed by integrally forming the main body 40, the flange 41, and the side plate 42 by molding a blank punched out from one plate. Specifically, first, the body portion 40 is formed by drawing the central portion of the blank into a deep dish shape, and the step 41b of the flange portion 41 is formed, and then the both side edges of the flange portion 41 are formed by bending. The continuous side plate portions 42 and 42 are formed.

  On the other hand, the lower member 5 is a deep-bottomed cylindrical shape obtained by deep-drawing a disk. Therefore, the lower member 5 is turned upside down and overlapped with the main body portion 40 of the upper member 4 from below and joined by spot welding. After the upper member 4 and the lower member 5 are thus combined, the inner peripheral side edge of the side wall portion 42 of the upper member 4 is arc welded to the side wall outer peripheral surface of the main body portion 40 of the upper member 4 and the side wall outer peripheral surface of the lower member 5, respectively. Join by. Thereby, the upper member 4 and the lower member 5 are firmly coupled and integrated, and the rigidity of the entire outer bracket 3 becomes very high.

  Then, the assembly of the inner bracket 1 and the rubber bullet body 2 is attached to the main body portion 40 of the upper member 4 of the outer bracket 3 thus configured from above, for example, by press-fitting or the like, as shown in FIG. As a result, the inner bracket 1 and the outer bracket 3 are connected by the rubber elastic body 2 to complete the upper mount M. As shown in FIG. 3, the round hole 1a of the inner bracket 1 is positioned substantially concentrically above the round holes 40a, 5a of the outer bracket 3, and the rod of the shock absorber S is inserted through the round holes 40a, 5a from below. The male threaded portion r1 of R is inserted into the round hole 1a.

  In addition, a bump stopper (denoted as D in FIG. 1 only) is extrapolated on the rod R of the shock absorber S mounted on the upper mount M as described above, and is fitted into the lower member 5 from the inside. The lower member 5 functions as a stopper mounting portion that holds the bump stopper. Further, as shown only in FIG. 3, the main body portion 40 and the lower member 5 of the upper member 4 are provided with through holes 40b and 5b, respectively, which prevent the accumulation of paint during production and water during use. It also functions as a hole.

  Therefore, according to the suspension / upper mount M according to this embodiment, first, the outer bracket 3 is made of a press-formed product of an iron plate, so that the cost can be reduced as compared with the casting of an aluminum alloy even in consideration of welding work. In addition, there is no electrolytic corrosion or nest problem.

  Further, the flange portion 41 fastened to the body panel of the automobile is provided with side plate portions 42 and 42 that hang down from both side edges thereof, and these are welded to the main body portion 40 and the lower member 5 of the upper member 4, and the flange portion 41. Since the step 41b functioning as a reinforcing rib is also provided in the portion 41, the support rigidity in the vertical direction of the upper mount M becomes very high.

  That is, when the suspension is rebounded, the upper mount M is subjected to a force that causes the flange 41a to be peeled off from the vehicle body panel. However, if the rigidity of the flange portion 41a and the upper mount M as a whole is increased as in this embodiment, sufficiently high support rigidity is ensured even with respect to the load at the time of rebound. can do.

  Since high support rigidity can be ensured in this way, it is not necessary to superimpose separate lid members, so that the weight can be reduced and the number of parts and the number of assembly steps can be reduced. Even if the side plate portion 42 is bent and the number of man-hours for welding the side plate portion 42 is increased, the increase in cost due to this can be substantially offset.

  Moreover, in the above-described embodiment, the upper member 4 is formed by integrally forming the main body portion 40, the flange portion 41, and the side plate portion 42 in the outer bracket 3 so that the upper member 4 is formed. In addition, it can be said that the number of parts is small and the structure is advantageous for cost reduction.

(Other embodiments)
The configuration of the present invention is not limited to that of the above-described embodiment, and may include other various configurations. That is, for example, the upper member 4 of the outer bracket 3 can be formed by welding the main body portion 40 and the flange portion 41 separately. In this way, although the number of welding points increases, a plurality of types having different fastening portions from each other. Since parts can be shared for the upper mount, it can be expected to reduce costs due to mass production.

  For example, in the above embodiment, the upper mount M of the type that is fastened to the vehicle body panel at two points is described. However, the upper mount M is not limited to this, and may be of a type that is fastened at three or four points. In this case, a plurality of types of mounts can be obtained at a low cost by changing the number of flange portions welded to the main body portion of the upper member.

  Further, in the embodiment, the step 41b of the flange portion 41 does not have to have a “<” shape in plan view, and gradually approaches the bolt hole 41a from both side edges of the flange portion 41 toward the center. In other words, the shape may be gradually separated from the center (axis Z) of the main body 40. Alternatively, the flange portion 41 may not have a step.

  In addition, a lid member that is superposed on the flange portion 41 can be added to the upper mount M of the above-described embodiment, similarly to the conventional sheet metal type.

  Further, in the outer bracket 3 of the above-described embodiment, a through hole 42a is formed in the side wall portion 42 of the upper member 4 so as to be opposed to each other for each flange portion 41 as shown in FIG. Also good. As shown in FIG. 6, if the shock absorber S is wound around the through hole 42 a through the strap 6 (bundling member), it can be assembled in a pre-compressed state, so the upper mount M is attached to the shock absorber S. It improves workability when it is assembled and transported to the vehicle body and assembled to the vehicle body.

  In addition, the part which engages with the strap 6 can be provided because there is a relatively large side wall portion 42 as in the upper mount M of the above-described embodiment. Even if it is going to form a part, it will cause the fall of rigidity and the raise of cost, and is difficult.

  Furthermore, the suspension using the upper mount according to the present invention is not limited to the trailing arm type as in the above-described embodiment, and other than that, for example, a wishbone type, multi-link type as well as a strut type suspension can be used. The upper mount according to the present invention is applicable.

  As described above, the upper mount according to the present invention is particularly suitable for a suspension of a passenger car because it can secure a sufficiently high support rigidity while being relatively low in cost, is excellent in reliability and can be reduced in weight. .

It is a schematic block diagram of the trailing arm type suspension of a motor vehicle in which the upper mount of the present invention is used. It is a perspective view which disassembles and shows an upper mount into an inner bracket, a rubber bullet body, and an outer bracket. FIG. 3 is a sectional view taken along line III-III in FIG. 2 showing the structure of the upper mount. It is a load-displacement graph showing the static spring characteristics of the upper mount. FIG. 3 is a view corresponding to FIG. 2 according to another embodiment. It is a figure which shows the assembly state assembled | attached to the shock absorber.

Explanation of symbols

S Shock absorber 1 Inner bracket (Inner bracket)
2 Rubber bullet body (elastic body)
3 Outer bracket (outer bracket)
4 Upper member 40 Body portion 41 Flange portion 41b Step 42 Side plate portion 42a Through hole 5 Lower member (stopper mounting portion)

Claims (5)

An upper mount for attaching the upper end of a shock absorber to a vehicle body side via an elastic body in a suspension system of an automobile,
An inner fitting fixed to the upper end of the shock absorber;
An outer fitting coupled to the inner fitting by the elastic body and fastened to the vehicle body panel,
The outer metal fitting has a bottomed cylindrical shape that opens upward, and extends from the upper edge of the main body portion so that the side wall surrounds the inner metal fitting to the fastening portion of the vehicle body side. A plate-like flange portion,
The flange portion is integrally formed with an iron-based plate material together with a pair of side plate portions that are bent and suspended from the left and right side edges when viewed in the extending direction, and each inner side edge of each side plate portion Is welded to the outer peripheral surface of the side wall of the main body.   The outer metal fitting has a cylindrical stopper mounting portion that is overlapped from the bottom to the bottom portion of the main body portion and opens downward. The outer peripheral surface of the side wall of the stopper mounting portion is also provided with each side plate portion. The upper mount according to claim 1, wherein the inner peripheral side edges are each welded.   The upper mount according to claim 1, wherein a main body portion and a flange portion of the outer metal fitting are integrally formed of an iron-based plate material.   A step is formed on the upper surface of the flange portion of the outer metal fitting so that the fastening portion with the vehicle body side is one step higher than the upper edge of the side wall of the main body, and the shape of this step is on both sides of the flange portion in plan view. The upper mount according to claim 3, wherein the upper mount has a “<” shape that gradually approaches the fastening portion from the edge toward the center.   The upper mount according to any one of claims 1 to 4, wherein through-holes are formed opposite to each other on both side wall portions that form a pair for each flange portion of the outer metal fitting.

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