JP2014031835A - Shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid interference of a lower part of a suspension spring with a tire even when the lower part of the suspension spring is broken.SOLUTION: A shock absorber comprises: a cylinder 1 a lower portion of which is connected to a side portion of an axle holding a tire T; a lower spring reception 2 provided in an outer periphery of the cylinder 1; and a suspension spring S a lower end of which is supported by the lower spring reception 2. The cylinder 1 includes an expanded diameter member 10 in a portion above the lower spring reception 2, and has a diameter at the expanded diameter member 10 larger than a diameter at a portion in which the lower spring reception 2 is provided.

Description

  The present invention relates to a shock absorber, and more particularly to an improvement of a shock absorber having a suspension spring formed of a coil spring and constituting a suspension in a vehicle.

  A shock absorber constituting a suspension in a vehicle is provided in a tire house of the vehicle, and an upper end portion is connected to a vehicle body side portion of the vehicle and a lower end portion is connected to an axle side portion of the vehicle.

  When the shock absorber is provided in the tire house, for example, as disclosed in Patent Document 1, the shock absorber is positioned on the tire so that the shock absorber is positioned on the back side of the tire house on the back side of the tire. Avoid interference.

JP 2010-247678 A

  However, in recent years, for example, the height position of the bonnet has been lowered from the viewpoint of collision safety in vehicles, and therefore, the upper end position of the tire house has been lowered, and therefore the height position at which the shock absorber is provided is compared with the previous level. As a result, the lower end of the suspension spring wound around the shock absorber tends to be positioned on the back side of the tire.

  Even if the lower end of the suspension spring is positioned on the back side of the tire, there is no risk that the lower end of the suspension spring will interfere with the tire when the shock absorber is in a normal operating state. If the suspension spring rusts after being used for a period of time, if the rusted lower end of the suspension spring breaks due to an unexpected external force applied to the shock absorber, the lower end of the suspension spring, which is said to be broken, interferes with the tire. This may damage the tires.

  The present invention has been devised in view of the above-described circumstances, and provides a shock absorber capable of avoiding interference of the lower end portion of the folded suspension spring with a tire even when the lower end portion of the suspension spring is broken. For the purpose.

  In order to achieve the above-described object, the shock absorber according to the present invention comprises a cylinder having a lower end connected to an axle side portion having a tire, a lower spring receiver provided on the outer periphery of the cylinder, and a lower spring receiver. A shock absorber having a suspension spring on which a lower end is supported, wherein the cylinder has a bulging portion at a position above the lower spring support, and an outer diameter of the bulging diameter portion provides the lower spring support. It is assumed that the diameter is larger than the outer diameter of the cylinder.

  Since the outer diameter of the swelled portion formed in the portion of the cylinder above the lower spring receiver is larger than the outer diameter of the cylinder in the portion where the lower spring receiver is provided, the lower end of the folded suspension spring is on the tire side. Even if it is going to move to, the lower end part of this broken suspension spring abuts against the inflated part and is prevented from moving toward the tire. Therefore, it can avoid that the lower end part of the broken suspension spring interferes with a tire.

It is a partial side view which shows the shock absorber by one Embodiment of this invention in a partial cross section.

  Hereinafter, the present invention will be described based on the illustrated embodiment. As shown in FIG. 1, the shock absorber according to the present invention has a lower end portion connected to an axle side portion (not shown) having a tire T. A cylinder 1, a lower spring receiver 2 provided on the outer periphery of the cylinder 1, and a suspension spring S having a lower end carried by the lower spring receiver 2.

  Although the shock absorber is not shown in detail in this embodiment, it is formed in a double cylinder shape, and the cylinder 1 is an outer cylinder, and is inserted into a cylinder provided inside the outer cylinder so as to be freely inserted and removed. The upper end side portion of the piston rod 3 is projected upward from the upper end portion of the cylinder 1.

  In the shock absorber shown in the figure, the cylinder 1 is a lower end side member, for example, has a knuckle bracket (not shown), is connected to an axle side portion of the vehicle, and the piston rod 3 has an upper end. For example, the side member has a mount (not shown) and is connected to a vehicle body side (not shown) in the vehicle.

  A bump stopper 4 formed in a cap shape having a downward U-shaped cross section is provided at the upper end portion of the cylinder 1 by press-fitting. The piston rod 3 is a shaft of the upper end portion (not shown) of the bump stopper 4. A hole (not shown) formed is inserted through the core.

  The bump stopper 4 is not shown, but a gap communicating with the hole is formed between the bump stopper 4 and the upper end portion of the cylinder 1 on the inner side, and so-called dust accumulated on the upper end of the bump stopper 4 through the gap is removed. 4 is discharged below the lower end.

  Although not shown, the upper end of the cylinder 1 has a rod guide on the inside and a seal member held by the rod guide, and the rod guide guides the relative movement of the piston rod 3 in the axial direction with respect to the cylinder 1. The space between the piston rod 3 and the cylinder 1 is sealed by the seal member.

  Although not shown, in the shock absorber, for example, a piston that is held by the piston rod 3 and slides in the cylinder has a damping means. Therefore, the damping is performed when the piston rod 3 enters and exits the cylinder 1. Means have a damping effect.

  The lower spring receiver 2 shown in the figure is a double cylinder type shock absorber. Therefore, the suspension spring S which is provided on the outer periphery of the cylinder 1 by welding and the lower end of which is supported by the lower spring receiver 2 is compressed. It is formed of a coil spring that is a spring. Incidentally, the coil spring is of course made of metal.

  Although not shown, the upper end of the suspension spring S is locked to an upper spring receiver provided at the upper end portion of the piston rod 3 below the mount, and therefore provided between the lower spring receiver 2 and the upper spring receiver. The suspension spring S is elastically supported by the urging force to be extended.

  In addition, although it is about the lower end of the suspension spring S, although what is illustrated is unground, this can expect more the strength with respect to the bending in the lower end part of the suspension spring S than the case where the lower end of the suspension spring S is ground. Therefore, it is not excluded that the lower end of the suspension spring S is ground when the present invention is embodied.

  On the other hand, the shock absorber according to the present invention has the expanded diameter portion 10 at a portion where the cylinder 1 is above the lower spring receiver 2, and the outer diameter of the expanded diameter portion 10 of the cylinder 1 at the portion where the lower spring receiver 2 is provided. The diameter is larger than the outer diameter.

  That is, in general, in the shock absorber, the outer diameter of the portion of the cylinder 1 that is above the lower spring receiver 2 is the same as the outer diameter of the portion of the cylinder 1 where the lower spring receiver 2 is provided and the lower portion thereof. It is said that.

  On the other hand, the shock absorber according to the present invention has an enlarged diameter portion 10 having a larger diameter than the so-called other portion of the cylinder 1 at a position above the lower spring receiver 2 in the cylinder 1. 10, particularly when the lower end of the suspension spring S is broken for some reason and the suspension spring S shortened accordingly moves to the tire side, it is broken as shown by a two-dot chain diagram in FIG. Abutting on the lower end S1 of the suspension spring S, the further movement of the suspension spring S toward the tire T is prevented.

  That is, in the shock absorber according to the present invention, the lower end portion S1 of the suspension spring S in which the expanded diameter portion 10 is broken is abutted, and the lower end portion of the suspension spring S is prevented from moving to the tire T side. The lower end S2 of the folded suspension spring S on the side facing the tire T cannot move further toward the tire T, and the lower end S2 of the folded suspension spring S interferes with the tire T. Can be avoided.

  In other words, if the lower end portion of the suspension spring S is bent due to rust or the like, the suspension spring S is shortened accordingly, and the suspension spring S is not seated on the lower spring receiver 2 and is therefore broken. The lower end S1 of the suspension spring S can move freely in the radial direction, that is, in the radial direction of the cylinder 1.

  If the lower end S2 of the folded suspension spring S on the side facing the tire T moves toward the tire T and interferes with the tire T, the tire T may be damaged. The suspended spring S on the side opposite to the tire T is prevented from moving to the tire T at the lower end S1 of the suspension spring S where the expanded diameter portion 10 on the outer periphery opposite to the outer periphery facing T is broken. The lower end S2 of the spring S is prevented from interfering with the tire T.

  In view of the above, the expanded diameter portion 10 may be arbitrarily formed as long as it is possible to prevent the lower end S1 of the suspension spring S from being moved toward the tire T.

  For forming the expanded diameter portion 10, it is possible to propose a measure for providing another member on the outer periphery of the cylinder 1, but this measure has a problem in that, for example, the number of parts is increased by using the separate member. Therefore, in the illustrated embodiment, no separate member is used for forming the expanded diameter portion 10.

  That is, in the illustrated embodiment, the expanded diameter portion 10 is formed in the cylinder 1, that is, in the outer cylinder when the shock absorber is a double cylinder type, and the outer cylinder is directly processed. Is going to be formed. Thereby, compared with the case where another member is provided in the cylinder 1 to form the enlarged diameter portion 10, it is not necessary to form the enlarged diameter portion 10 in the cylinder 1.

  Not only that, but the expanded diameter portion 10 is not formed by so-called retrofitting to the outer periphery of the cylinder 1 as a separate member, and as a result of long-term use, the expanded diameter portion 10 falls off due to rust or deterioration of the retrofitted portion. This is advantageous in that the arrangement state of the expanded diameter portion 10 can be permanently maintained.

  In many cases, the diameter of the tube 1 is increased (bulge processing) for forming a portion having a large diameter, that is, a large diameter portion and a portion having a small diameter, that is, a small diameter portion. Depending on the diameter reduction processing (drawing processing), it is sufficient if the large diameter portion and the small diameter portion are formed as a result. Various processing methods for forming the large-diameter portion and the small-diameter portion in a single cylinder are well known, and a description thereof will be omitted here.

  As shown in the figure, the diameter of the cylinder 1 is increased so that the portion of the cylinder 1 that is above the lower spring receiver 2 is the large diameter portion, that is, the expanded diameter portion 10. The portion below 2 is the small diameter portion 11.

  In addition, in the place shown in the figure, the upper portion of the expanded diameter portion 10 in the cylinder 1 is left at the original diameter of the cylinder 1, and the upper diameter portion of the cylinder 1 is made the same as the lower diameter portion 11 below. The upper end small diameter portion 12 is formed.

  As described above, the bump stopper 4 is press-fitted into the upper end small-diameter portion 12. However, the outer diameter of the expanded-diameter portion 10 may coincide with the outer diameter of the bump stopper 4. As long as it is not small, it may be small or large.

  By the way, the expanded diameter portion 10, that is, the large diameter portion, of course, has an outer diameter larger than the outer diameter of the small diameter portion 11, for example, although not shown, when the shock absorber is a double cylinder type, The thickness dimension that is substantially the same as the radial dimension of the reservoir formed between the cylinder and the inner cylinder is made larger than that of the small diameter portion 11.

  That is, for the so-called thick dimension in which the expanded diameter portion 10 is larger in diameter than the small diameter portion 11, the lower end of the suspended spring S is folded even if the lower end S <b> 1 of the folded suspension spring S moves in the radial direction of the cylinder 1. The optimal numerical value is selected from the outer diameter of the cylinder 1 and the winding diameter and wire diameter of the suspension spring S so that the portion S2 can be prevented from interfering with the tire T. Incidentally, when the suspension spring S is in a normal state, the dimensions are set so that the inner periphery of the suspension spring S does not interfere with the outer periphery of the expanded diameter portion 10.

  As for the shape of the outer peripheral surface of the expanded diameter portion 10, if it is a result of the diameter expansion processing on the cylinder 1, it will generally be formed concentrically with the outer peripheral surface of the cylinder 1, but the folded suspension spring S From the standpoint of preventing further movement by bringing the lower end portion S1 into contact with each other, it may not be concentric with the outer peripheral surface of the cylinder 1, although not shown.

  Incidentally, when the bulging portion 10 is formed concentrically with the outer peripheral surface of the cylinder 1, the bulging portion 10 has no directionality in the circumferential direction. When the lower spring receiver 2 is welded to the outer periphery of the cylinder 1, so-called positioning work in the circumferential direction is not required, and the welding work is not complicated.

  Further, the outer peripheral surface of the expanded diameter portion 10 may not be concentric with the outer peripheral surface of the cylinder 1 but may be formed as a corrugated surface continuous in the circumferential direction or a polygonal surface connecting a plurality of flat surfaces. The hobbing property can be given to the appearance of the expanded diameter portion 10, that is, the cylinder 1.

  When assembling the shock absorber, the lower spring receiver 2 is welded to the outer periphery of the cylinder 1. In this case, since the cylinder 1 is preliminarily formed with the expanded diameter portion 10, the expanded diameter is reduced. The portion 10 serves as a guide for setting the fixing position of the lower spring receiver 2 when the lower spring receiver 2 is provided on the cylinder 1.

  In addition, the expanded diameter portion 10 is formed over almost the entire length from the lower spring receiver 2 to the bump stopper 4 that forms the upper end portion of the cylinder 1, but the suspended suspension spring S is broken. From the viewpoint of preventing the lower end S1 from moving to the tire T side, although not shown, the expanded diameter portion 10 may be formed shorter than the above, and the upper end position may be further lowered. The appearance of the cylinder 1 can be improved as compared with the case where the expanded diameter portion 10 is formed long.

  In addition, the lower end side part (not shown) of the dust cover 5 is positioned inside the suspension spring S provided with the expanded diameter part 10, as shown by a two-dot chain line diagram in FIG. Considering this, the expanded diameter portion 10 functions so as to narrow the clearance between the cylinder 1 and the dust cover 5, and by providing the expanded diameter portion 10, the intrusion of dust from the outside. It can be said that this can be suppressed.

  As described above, the suspension spring S is wound so as not to be inclined with respect to the shock absorber. Alternatively, although not shown, the suspension spring S may be wound so as to be inclined with respect to the shock absorber. Even in that case, it is a matter of course that the expanded diameter portion 10 can prevent the lower end portion S1 of the broken suspension spring S from moving toward the tire T side.

  Moreover, in the above place, although the lower end of the suspension spring S is in direct contact with the lower spring receiver 2, instead of this, a rubber sheet is provided between the lower end of the suspension spring S and the lower spring receiver 2. May be.

  In this case, as a matter of course, it is possible to suppress the occurrence of rust at the lower end of the suspension spring S, which may appear due to direct contact between the lower end of the suspension spring S and the lower spring receiver 2, as much as possible. The shock absorption between the two becomes possible, and the generation of impact sound can be reduced.

  Further, in the above description, the expanded diameter portion 10 is formed without using another member. However, even if the vehicle is used for a long time exceeding the service life, the expanded diameter portion is deteriorated by rust or dropped off. If it is ensured that it does not occur, the expanded diameter portion 10 may be provided on the outer periphery of the cylinder 1 by using another member.

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Lower spring holder 3 Piston rod 4 Bump stopper 5 Dust cover 10 Expansion diameter part 11 Small diameter part 12 Upper end small diameter part S Suspension spring S1, S2 Lower end part T Tire

Claims (3)

In a shock absorber having a cylinder having a lower end connected to an axle side portion having a tire, a lower spring receiver provided on the outer periphery of the cylinder, and a suspension spring having a lower end carried by the lower spring receiver,
The cylinder has an enlarged diameter portion at a position above the lower spring support, and the outer diameter of the expanded diameter section is larger than the outer diameter of the cylinder at the position where the lower spring support is provided. A shock absorber.   2. The shock absorber according to claim 1, wherein an upper end small diameter portion that forms an upper end portion of the cylinder is formed above the expanded diameter portion, and a bump stopper is press-fitted into the upper end small diameter portion.   The shock absorber according to claim 1 or 2, wherein the expanded diameter portion is formed by a diameter expansion process or a diameter reduction process on the cylinder.

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