JP6374784B2 - Knuckle bracket and shock absorber - Google Patents

Description

  The present invention relates to a knuckle bracket and a shock absorber.

  Conventionally, a shock absorber is interposed between a vehicle body and a wheel of a vehicle and used for the purpose of suppressing vehicle body vibration. In particular, the strut type shock absorber includes a knuckle bracket for connecting an end portion thereof to a steering knuckle on the wheel side. For example, the knuckle bracket described in Patent Documents 1 and 2 includes a holding portion that holds the outer shell of the shock absorber and is welded to the outer shell, and a pair of holding portions that are fastened to the steering knuckle by bolts. Prepare.

JP-A-7-305707 JP 2006-273173 A

  Here, in the knuckle bracket in which the above-mentioned holding part is welded to the outer shell, for the purpose of reducing the weight, reducing the cost, etc., if a back hole that penetrates the holding part is formed in the holding part, Blow holes may occur. And when a blowhole arises in a welding part in this way, there exists a possibility that the favorable joining state of an outer shell and a knuckle bracket cannot be maintained.

  Then, this invention makes it a subject to provide the knuckle bracket which can maintain the favorable joining state to an outer shell, and the shock absorber which can maintain the favorable joining state of an outer shell and a knuckle bracket.

  According to the first and second aspects of the invention for solving the above-mentioned problems, the knuckle bracket is viewed in the axial direction, and a hole is provided between the welded portion and the back hole in the holding portion. For this reason, it can prevent that the gas generated at the time of welding is discharged to the outside of the holding portion through the hole and the blow hole is generated in the welded portion.

  According to a third aspect of the present invention, in addition to the configuration according to the second aspect, two holes are provided on both sides of a straight line that passes through the center of the dorsal hole and extends along the axial direction of the holding portion. It is done. For this reason, generation | occurrence | production of a blowhole can be prevented reliably and efficiently. In addition, the strength of the knuckle bracket can be maintained even if a hole is provided between the back hole and the weld.

  In the invention according to claim 4, in addition to the configuration according to claim 2 or claim 3, the edge of the dorsal hole is a quadrangular shape with rounded corners, and four straight edges, And four arcuate edges. Any one of the holes is provided on a straight line that extends along the axial direction of the holding portion through a boundary between the linear edge portion on the welded portion side and the arc-shaped edge portion. For this reason, generation | occurrence | production of a blowhole can be prevented reliably and efficiently.

  According to the present invention, a good joined state between the outer shell and the knuckle bracket can be maintained.

It is the front view which simplified and showed the attachment state of the shock absorber concerning one embodiment of the present invention. It is the front view which expanded the principal part of the buffer which concerns on one embodiment of this invention, and showed it partially notching. FIG. 3 is a right side view of FIG. 2. (A) is AA sectional drawing of the knuckle bracket of the buffer which concerns on one embodiment of this invention. (B) is BB sectional drawing of the knuckle bracket of the buffer which concerns on one embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. The same reference numerals used throughout the several drawings indicate the same parts.

  As shown in FIG. 1, a shock absorber D according to an embodiment of the present invention includes an outer shell 1 and a knuckle bracket 2 that connects the outer shell 1 to the wheel W side. The knuckle bracket 2 has a holding portion 30 that is curved along the outer peripheral shape of the outer shell 1 and whose end is welded to the end of the outer shell 2. As shown in FIGS. 2 and 3, the holding part 30 is formed between a back hole 30 a penetrating the thickness of the holding part 30 and a part or all of the weld part Y and the back hole 30 a when viewed in the axial direction. And one or more holes 30b.

  The shock absorber D according to the present embodiment is a strut-type shock absorber, and the shock absorber D itself is used as a vehicle wheel positioning support. In the present embodiment, the shock absorber D is set to a single cylinder type. The shock absorber D is slidably inserted into the outer shell 1 while being held by the outer shell 1, the piston rod 10 (FIG. 1) entering and exiting the outer shell 1, and the tip of the piston rod 10. A piston (not shown) and a free piston (not shown) slidably inserted on the side opposite to the piston rod in the outer shell 1 are provided. In the outer shell 1, an extension side chamber on the piston rod 10 side and a pressure side chamber on the piston side, which are partitioned by a piston and filled with hydraulic oil, are formed. Further, in the outer shell 1, an air chamber is formed which is partitioned from the pressure side chamber by a free piston and in which gas is enclosed. Further, the piston is formed with a damping passage that provides resistance to the flow of hydraulic oil that passes between the extension side chamber and the compression side chamber.

  And the outer shell 1 is connected with the wheel W side, and the piston rod 10 is connected with the vehicle body side which is not shown in figure. For this reason, when an impact caused by road surface unevenness is input to the wheel W, the piston rod 10 enters and exits the outer shell 1 and the shock absorber D expands and contracts. Thus, when the shock absorber D expands and contracts, the hydraulic oil passes through the attenuation passage, so that a differential pressure is generated between the expansion side chamber and the compression side chamber, and a damping force that suppresses expansion and contraction of the shock absorber D is generated. Further, when the shock absorber D expands and contracts, the volume of the piston rod 10 entering and exiting the outer shell 1 and the inner shell inner volume change, but the change can be compensated by expansion and contraction of the air chamber accompanying the movement of the free piston.

  Thus, in this Embodiment, the outer shell 1 functions as a cylinder which accommodates hydraulic fluid. However, the configuration of the shock absorber D can be arbitrarily changed. For example, the outer shell 1 functioning as a cylinder may be double or more inside and outside, and the shock absorber D may be set to a double cylinder type. In the present embodiment, the piston rod 10 is connected to the vehicle body side, the cylinder (outer shell 1) is connected to the wheel W side, and the shock absorber D is an upright type. However, the piston rod 10 may be connected to the wheel W side and the shock absorber D may be an inverted type. In this case, the outer shell 1 functions as an outer tube that covers the outer periphery of the piston rod 10 and in which the cylinder enters and exits.

  Subsequently, the knuckle bracket 2 for connecting the outer shell 1 to the wheel W side has a two-plate structure including the outer bracket 3 having the holding portion 30 and the inner bracket 4 as shown in FIG.

  The outer bracket 3 includes a holding portion 30 that is curved along the outer peripheral shape of the outer shell 1 and a pair of holding portions 31 and 31 that stand up from both ends in the circumferential direction of the holding portion 30. The holding part 30 has a shape in which a part of a cylinder is cut, and has an arc shape when viewed in the axial direction. The circumferential length of the holding part 30 is longer than the circumference of a semicircle having the radius of curvature of the holding part 30 as a radius. In addition, the pair of sandwiching portions 31, 31 are arranged at a predetermined interval, and each sandwiching portion 31 extends substantially parallel to a straight line passing through the diameter of the retaining portion 30.

  The other inner bracket 4 is inserted between the pair of sandwiching portions 31, 31 and is bent along the outer peripheral shape of the outer shell 1, and from both ends in the circumferential direction of the auxiliary holding portion 40. It has a pair of auxiliary clamping parts 41, 41 standing up against each other. The auxiliary holding unit 40 fills the cut portion of the holding unit 30, and the auxiliary holding unit 41 extends along the holding unit 31.

  When the inner bracket 4 is joined to the outer bracket 3 to form the knuckle bracket 2, the holding portion 30 and the auxiliary clamping portion 40 have a substantially cylindrical shape, and the outer shell 1 is press-fitted inside the cylindrical portion 20. it can. The wheel side opening of the outer shell 1 is closed with a lower cap 11 as shown in FIG. 2, and the outer shell 1, the lower cap 11, the holding portion 30 and the auxiliary holding portion 40 are arc welded, The knuckle bracket 2 and the outer shell 1 are integrated. In addition, bolt insertion holes 31a and 41a communicating with each other are formed in the upper and lower portions of the clamping portion 31 and the auxiliary clamping portion 41, respectively. The knuckle bracket 2 is fastened to the steering knuckle N with bolts that are inserted into the bolt insertion holes 31a and 41a.

  In the present embodiment, since the knuckle bracket 2 includes the cylindrical portion 20 as described above, the wheel side end portion of the outer shell 1 can be welded to the knuckle bracket 2 over the entire circumference, and the outer shell 1 and the knuckle can be welded. The bracket 2 can be firmly welded.

  In addition, the structure of the knuckle bracket 2 can be arbitrarily changed, and the inner bracket 4 may be eliminated and a single plate structure having only the outer bracket 3 may be used. Further, in the present embodiment, the lower end in FIG. 2 of the knuckle bracket 2 protrudes downward from the lower end in FIG. 2 of the outer shell 1, and the wheel side end inner periphery of the knuckle bracket 2 is The wheel side end of the outer shell 1 is welded all around. In the present embodiment, the portion indicated by Y in FIG. 2 is a welded portion, but the welding position between the knuckle bracket 2 and the outer shell 1 can be arbitrarily changed.

  In addition, the holding portion 30 of the outer bracket 3 is formed with a back hole 30a penetrating the thickness of the holding portion 30 for the purpose of reducing the weight of the knuckle bracket 2 by reducing the material and reducing the cost. . In the present embodiment, one back hole 30a is provided on the opposite side of the cut portion of the holding portion 30, and the shape when the outer bracket 3 is expanded is a quadrangular shape with rounded corners. In the holding portion 30 that curves along the outer shell 1, the circumferential length of the back hole 30a is set so that the central angle θ1 is about 110 degrees (FIG. 4). As shown in FIG. 3, the edge E of the square back hole 30 a with rounded corners is composed of four linear edges e 1, e 2, e 3, e 4 corresponding to the sides of the square and four circles corresponding to the corners. It has arcuate edges e5, e6, e7, e8. In the back hole 30 a, a pair of short linear edges e 2, e 4 facing each other are aligned in the axial direction of the holding part 30, and a pair of long linear edges e 1, e 3 facing each other are aligned in the circumferential direction of the holding part 30. It is like that.

  Furthermore, the holding part 30 of the outer bracket 3 has a gap between the welded part Y (FIG. 2) and the back hole 30a when the holding part 30 is viewed from one end in the axial direction (when viewed in the axial direction). Two circular holes 30b, 30b are formed side by side in the circumferential direction in the position (FIG. 3).

  The two holes 30b and 30b pass through the boundary between the linear edge e4 on the welded part Y side and the arcuate edge (e7 or e8) connected to the linear edge e4, and the axial direction of the holding part 30 Are provided on a straight line extending along the line. In the present embodiment, the central angle θ2 with respect to the arc connecting the center of each hole 30b, 30b and the center of the back hole 30a is about 36 degrees (FIG. 4B).

  According to this configuration, it is possible to prevent the gas generated when welding the knuckle bracket 2 and the outer shell 1 from passing through the hole 30b to the outside of the holding portion 30 and generating a blow hole in the welded portion Y. Therefore, the good joining state of the knuckle bracket 2 and the outer shell 1 can be maintained.

  Further, the hole 30b is set so as not to overlap the welded portion Y. For this reason, the molten metal does not flow out of the hole 30b during welding.

  Moreover, the part provided with the hole 30b is a part where the occurrence frequency of blow holes is high from experience. For this reason, if the hole 30b is provided in this part, generation | occurrence | production of a blowhole can be prevented reliably and efficiently.

  Moreover, in this Embodiment, the hole 30a is a round hole provided in two places, and is formed as small as possible in the range which can escape the gas at the time of welding. For this reason, the strength of the knuckle bracket 2 can be maintained while preventing the occurrence of blow holes.

  The number and shape of the holes 30b can be arbitrarily changed. For example, the hole 30b may be a long hole, and a part of the hole 30b may protrude from between the welded portion Y and the back hole 30a when viewed in the axial direction.

  Further, in the present embodiment, since the gas venting during welding is realized by the holes 30b, the holes 30b can be formed simultaneously with the back vent holes 30a in the process of forming the back vent holes 30a (for example, during blanking). Therefore, the process of forming the holes 30b can be easily incorporated into the manufacturing process of the conventional outer bracket 3. However, the formation method and formation process of the hole 30b can be arbitrarily changed.

  In the present embodiment, the end of the outer bracket 3 on the vehicle body side is curved outward from the holding part 30 to the holding part 31 to form a rib 32. However, the wheel side end of the outer bracket 3 has a straight shape. Thus, in the knuckle bracket 2 which is not provided with the rib at the wheel side end, it is confirmed that the frequency of occurrence of blow holes is high. Therefore, as in the present embodiment, it is particularly effective to provide the holes 30b and suppress the generation of blow holes.

  Hereinafter, the assembly | attachment process to the outer shell 1 of the knuckle bracket 2 which concerns on this Embodiment is demonstrated.

  The outer bracket 3 and the inner bracket 4 are joined to form the knuckle bracket 2, and the base cap 11 is assembled to the outer shell 1. Then, the outer shell 1 is press-fitted into the cylindrical portion 20 of the knuckle bracket 2, and with the wheel side end portion (lower side in FIG. 2) facing upward, the inner periphery of the lower portion in FIG. The lower end of the outer shell 1 in FIG. At this time, the knuckle bracket 2, the outer shell 1, and the base cap 11 are welded at the same time, and a weld bead is formed in the welded portion Y in an annular shape.

  As described above, the knuckle bracket 2 is provided with the hole 30b between the welded portion Y and the back hole 30a when viewed in the axial direction. For this reason, the gas produced by welding escapes to the outside of the holding portion 30 through the hole 30b. Therefore, it is possible to prevent a blow hole from being generated in the welded portion (weld bead) Y and maintain a good joined state between the knuckle bracket 2 and the outer shell 1.

  Hereinafter, the operational effects of the knuckle bracket 2 according to the present embodiment and the shock absorber D including the knuckle bracket 2 will be described.

  In the present embodiment, the edge E of the back hole 30a has a quadrangular shape with rounded corners, and includes four linear edge portions e1, e2, e3, e4 and four arc-shaped edge portions e5, e6. , E7, e8. And the hole 30b is provided on the straight line which passes along the boundary of the linear edge part e4 and arcuate edge part e7, e8 by the side of the welding part Y, and extends along the axial direction of the holding part 30. FIG.

  According to this structure, generation | occurrence | production of a blowhole can be prevented reliably and efficiently. The position where the hole 30b is provided can be arbitrarily changed as long as the generation of blow holes can be suppressed.

  In the present embodiment, two holes 30b are provided on both sides of a straight line that extends along the axial direction of the holding portion 30 through the center of the back hole 30a.

  According to this structure, generation | occurrence | production of a blowhole can be prevented reliably and efficiently. In addition, the strength of the knuckle bracket 2 can be maintained. The number of holes 30b can be arbitrarily changed as long as the occurrence of blow holes can be suppressed.

  Moreover, in this Embodiment, the buffer D is provided with the outer shell 1 and the knuckle bracket 2 which connects the outer shell 1 to the wheel W side. The knuckle bracket 2 has a holding portion 30 that is curved along the outer peripheral shape of the outer shell 1 and whose end is welded to the end of the outer shell 1. The holding part 30 has a back hole 30a penetrating the thickness of the holding part 30, and one or more holes 30b formed between the welded part Y and the back hole 30a when part or all of the holding part 30 is viewed in the axial direction. Including.

  According to this structure, the gas at the time of welding can escape to the outer side of the holding part 30 from the hole 30b. Therefore, generation | occurrence | production of a blow hole can be prevented and the favorable joining state of the outer shell 1 and the knuckle bracket 2 can be maintained.

  Although the preferred embodiments of the present invention have been described in detail above, modifications, changes and modifications can be made without departing from the scope of the claims.

D ... Shock absorber, E ... Edge, e1, e2, e3, e4 ... Linear edge, e5, e6, e7, e8 ... Arc-like edge, Y ... Welded part, DESCRIPTION OF SYMBOLS 1 ... Outer shell, 2 ... Knuckle bracket, 30 ... Holding part, 30a ... Back hole, 30b ... Hole

Claims (4)

Curved along the outer peripheral shape of the outer shell of the shock absorber, the end portion has a holding portion welded to the end portion of the outer shell,
The holding part includes a back hole that penetrates the thickness of the holding part, and one or more holes that are partially or entirely formed between the weld part and the back hole when viewed in the axial direction. A knuckle bracket characterized by that. An outer shell,
A knuckle bracket for connecting the outer shell to the wheel side,
The knuckle bracket is curved along the outer peripheral shape of the outer shell, and has a holding portion whose end is welded to the end of the outer shell,
The holding part includes a back hole that penetrates the thickness of the holding part, and one or more holes that are partially or entirely formed between the weld part and the back hole when viewed in the axial direction. A shock absorber characterized by that. 3. The shock absorber according to claim 2, wherein the hole is provided at two positions on both sides of a straight line that passes through a center of the back hole and extends along the axial direction of the holding portion. The edge of the dorsal hole has a quadrangular shape with rounded corners, and has four linear edges and four arc-shaped edges,
Any one of the holes is provided on a straight line that extends along an axial direction of the holding portion through a boundary between the linear edge portion on the welded portion side and the arc-shaped edge portion. The shock absorber according to claim 2 or claim 3.

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