JP2017155858A - Air spring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air spring capable of improving the durability while restricting the increase in weight.SOLUTION: An air spring 1 comprises: a first mounting component 2 connected to one of a vibration generating part and a vibration receiving part; a second mounting component 3 connected to the other thereof; and a cylindrical diaphragm 4 with one end part 4a mounted to the first mounting component 2 and with the other end part 4b mounted to the second mounting component 3, in which an air chamber 5 is defined between the first mounting component 2, the second mounting component 3, and the diaphragm 4. The first mounting component 2 includes: a flat plate part 23; and a cylindrical projection 24 that is protruding from the flat plate part 23 toward in the air chamber 5 and that is fitted to the one end part 4a of the diaphragm 4. The flat plate part 23 includes: a thick part 23a located on the outside of the projection 24 in the radial direction; and a thin wall part 23b located on the inner side of the projection 24 in the radial direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an air spring.

  Conventionally, for example, as shown in Patent Document 1 below, a first attachment member connected to one of a vibration generating portion and a vibration receiving portion, a second attachment member connected to the other, and one end portion Is attached to the first attachment member, and a cylindrical diaphragm is attached to the second attachment member at the other end, and an air chamber is provided between the first attachment member, the second attachment member, and the diaphragm. A defined air spring is known.

International Publication No. 2013/156190

  However, the conventional air spring has room for improvement in improving durability while suppressing an increase in weight.

  The present invention has been made in view of the above problems, and an object thereof is to provide an air spring capable of improving durability while suppressing an increase in weight.

  In order to solve the above-described problem, an air spring according to the present invention includes a first mounting member connected to one of a vibration generating unit and a vibration receiving unit, and a second mounting member connected to the other. A cylindrical diaphragm with one end attached to the first attachment member and the other end attached to the second attachment member, the first attachment member, the second attachment member, and the An air spring in which an air chamber is defined between the diaphragm and the diaphragm, wherein the first mounting member projects from the flat plate portion toward the air chamber and is fitted into one end portion of the diaphragm. A cylindrical projecting portion, and the flat plate portion is a thick portion positioned radially outside the projecting portion, and a thin portion positioned radially inside the projecting portion, It is characterized by having.

  According to this invention, a thick part is located in the part located in the radial direction outer side from the protrusion part fitted in the one end part of a diaphragm among the flat plate parts of a 1st attachment member. For this reason, when a compressive force in the axial direction is applied to the air spring and the outer peripheral surface on one end side of the diaphragm is abutted against the thick wall portion, the flat plate portion is deformed by the force transmitted from the diaphragm to the flat plate portion. Can be suppressed, and durability can be improved. In addition, the entire flat plate portion is not thickened, but is thickened only in a portion where the outer peripheral surface on the one end portion side of the diaphragm comes into contact, so that an increase in weight can be suppressed.

Here, the flat plate portion and the protruding portion are formed of a single metal plate, and the thick portion of the flat plate portion includes a bent portion positioned at a radially outer end portion and a radially outer end portion. They may be connected to each other via the bent portion, and may include two flat portions overlapped with each other.
In this case, since the flat plate portion and the projecting portion of the first mounting member are formed of a single metal plate, leakage of air in the air chamber through the connecting portion between the flat plate portion and the projecting portion is generated. Can be prevented.

  According to this invention, durability can be ensured while suppressing an increase in weight.

It is a longitudinal section of an air spring shown as one embodiment concerning the present invention.

Hereinafter, an embodiment of an air spring according to the present invention will be described with reference to FIG.
The air spring 1 includes a first attachment member 2 connected to one of the vibration generating portion and the vibration receiving portion, a second attachment member 3 connected to the other, and one end portion 4a of the first attachment member. 2 and a cylindrical diaphragm 4 whose other end 4b is attached to the second attachment member 3, and air between these first attachment member 2, second attachment member 3 and diaphragm 4 is provided. Chamber 5 is defined.

Hereinafter, the direction along the central axis O of the diaphragm 4 is referred to as an axial direction, and in the axial direction, the first mounting member 2 side is referred to as an upper side, and the second mounting member 3 side is referred to as a lower side. In a plan view viewed from the axial direction, a direction orthogonal to the central axis O is referred to as a radial direction, and a direction around the central axis O is referred to as a circumferential direction.
Here, the air spring 1 is disposed, for example, between a vehicle body or the like as a vibration receiving portion and a suspension arm or the like as a vibration generating portion that is swingably supported by the vehicle body. For example, the 1st attachment member 2 is attached to a vibration receiving part, and the 2nd attachment member 3 is attached to a vibration generation part.

The first mounting member 2 includes a flat plate portion 23 and a cylindrical protruding portion 24 that protrudes from the flat plate portion 23 into the air chamber 5 and is fitted into one end portion 4 a of the diaphragm 4. .
The flat plate portion 23 is a circular metal plate in a plan view viewed from the axial direction, and is disposed coaxially with the central axis O. A cylindrical introduction member 22 to which a pipe joint is connected when air is supplied to the air chamber 5 located below the flat plate portion 23 is disposed in the central portion in the radial direction on the upper surface of the flat plate portion 23. ing. An internal thread portion is formed on the inner peripheral surface of the introduction member 22. The introduction member 22 is connected to the upper surface of the flat plate portion 23 by, for example, welding. Instead of the introduction member 22, an introduction member having an external thread portion formed on the outer peripheral surface may be employed.
Further, on the upper surface of the flat plate portion 23, a connecting plate 21 attached to a vibration receiving portion (not shown) is disposed. The connecting plate 21 is connected to the upper surface of the flat plate portion 23 by, for example, welding. The connecting plate 21 has a plurality of through holes into which connecting members such as bolts are inserted when attached to the vibration receiving portion.

  The protruding portion 24 is a cylindrical body that protrudes downward from the lower surface of the flat plate portion 23. Further, the protruding portion 24 is disposed coaxially with the central axis O. The protruding portion 24 is fitted in the one end portion 4 a of the diaphragm 4 in an airtight manner. A bead (not shown) extending continuously over the entire circumference is embedded in the one end 4 a of the diaphragm 4.

  The second mounting member 3 is formed in a bottomed cylindrical shape, a bottom 3a to which a vibration generating unit (not shown) is connected, an outer cylinder 3b extending upward from the outer peripheral edge of the bottom 3a, and an outer cylinder An annular step portion 3c extending from the upper end portion of 3b toward the inside in the radial direction, and an open tube portion 3d protruding upward from the inner peripheral edge portion of the step portion 3c are provided. The bottom part 3a, the outer cylinder part 3b, the step part 3c and the opening cylinder part 3d are arranged coaxially with the central axis O, respectively.

The bottom portion 3a includes an annular outer peripheral portion 3e, and a disc portion 3f having an outer peripheral edge connected to the inner peripheral edge of the outer peripheral portion 3e and positioned below the outer peripheral portion 3e. Each of the outer peripheral portion 3e and the disc portion 3f is disposed coaxially with the central axis O. A raised portion 3g that protrudes upward is formed on the disc portion 3f. The raised portion 3g is formed in a crested cylindrical shape, and an internal thread portion is formed on the inner peripheral surface thereof. In the illustrated example, one female screw portion is formed on the bottom portion 3a, but a plurality of female screw portions may be formed. The lower end opening of the raised portion 3g is opened on the lower surface of the bottom portion 3a. The raised portion 3g is disposed in the central portion in the radial direction of the disc portion 3f.
Instead of the raised portion 3g protruding upward from the bottom portion 3a, a protruding portion protruding downward from the bottom portion 3a may be formed, and a male screw portion may be formed on the outer peripheral surface thereof. A plurality of the protruding portions may be formed on the bottom portion 3a.

The outer cylindrical portion 3b gradually increases in thickness toward the outside in the radial direction as it goes upward, and the outer peripheral surface of the diaphragm 4 is in contact with the outer peripheral surface located above the outer cylindrical portion 3b.
The upper end opening edge of the outer cylinder part 3b is formed in the shape of a curved surface projecting upward. The upper surface of the step portion 3c is formed in a concave curved shape that is recessed downward, and the upper end opening edge of the outer cylinder portion 3b and the upper surface of the step portion 3c are smoothly connected without a step.
The opening cylinder portion 3d is opened upward, whereby the internal spaces of the second mounting member 3 and the diaphragm 4 are communicated with each other, and the air chamber 5 is defined.
The opening cylinder portion 3 d of the second attachment member 3 is fitted in the other end portion 4 b of the diaphragm 4 in an airtight manner. A bead (not shown) extending continuously over the entire circumference is embedded in the other end portion 4 b of the diaphragm 4.

The diaphragm 4 is configured by a rubber film. The diaphragm 4 is integrally in contact with the outer peripheral surface of the opening cylindrical portion 3d, the upper surface of the stepped portion 3c, the upper end opening edge of the outer cylindrical portion 3b, and the outer peripheral surface of the outer cylindrical portion 3b. The diaphragm 4 is bent outward in the radial direction from the lowest position and is turned upward.
The shape of the diaphragm 4 is, instead of being folded back as described above, extending substantially straight in the axial direction, and the outer peripheral surface of the opening cylindrical portion 3d, the upper surface of the stepped portion 3c, the protruding portion 24, , May be directly connected.

And in this embodiment, the flat plate part 23 has the thick part 23a located in the radial direction outer side rather than the protrusion part 24, and the thin part 23b located in the radial direction inner side rather than the protrusion part 24. ing.
The thick portion 23a has an annular shape arranged coaxially with the central axis O in a plan view viewed from the axial direction. The outer peripheral surface of one end portion 4a of the diaphragm 4 is in contact with the lower surface of the thick portion 23a. For this reason, when the diaphragm 4 is elastically deformed by the compressive force in the axial direction, the outer peripheral surface of the one end portion 4a is abutted against the lower surface of the thick portion 23a, so that the thick portion 23a receives external force from the diaphragm 4. It has become.
The thin portion 23b has a circular shape arranged coaxially with the central axis O in a plan view seen from the axial direction. A connecting plate 21 and an introduction member 22 are disposed on the upper surface of the thin portion 23b. The thickness of the thin portion 23b is half the thickness of the thick portion 23a.

The flat plate portion 23 and the projecting portion 24 are formed of a single metal plate, and the thick portion 23a of the flat plate portion 23 includes a bent portion 23c located at the outer end portion in the radial direction and the outer end portions in the radial direction. Are connected via a bent portion 23c, and two flat portions 23d that are overlapped with each other.
The bent portion 23c is formed in a curved shape protruding outward in the radial direction, and the two flat portions 23d are overlapped with each other in the axial direction. The upper end portion of the projecting portion 24 and the inner peripheral edge of the flat portion 23d located below the two flat portions 23d are connected via a concave curved surface portion 24a.
The metal plate has a uniform thickness over the entire area, and the thicknesses of the two flat portions 23d are equal to each other.

The first mounting member 2 is a flat cylindrical shape in which a disk-shaped metal plate is first pressed, its outer peripheral portion is bent so as to be parallel to the axial direction, and one end is closed by a closing plate portion. Form the body. Next, of the peripheral wall portion of the cylindrical body, the portion located on the other end side is kept parallel to the axial direction, and the portion located on the one end side is bent toward the inner side in the radial direction, and the outer periphery of the closing plate portion Superimpose on the club.
Thereby, the flat plate part 23 provided with the thick part 23a and the thin part 23b, and the protrusion part 24 are formed with one metal plate.

Next, the operation of the air spring 1 according to the present embodiment will be described.
The connecting plate 21 of the first attachment member 2 is attached to the vibration receiving portion, the bottom portion 3a of the second attachment member 3 is attached to the vibration generating portion, a pipe joint is connected to the introduction member 22, and the air chamber 5 has a predetermined pressure. Air is introduced and sealed until.
In this state, when the first mounting member 2 and the second mounting member 3 are relatively displaced, the diaphragm 4 is deformed, so that the load transmitted from the one end portion 4a of the diaphragm 4 to the thick portion 23a of the flat plate portion 23. Also fluctuate.

At this time, the diaphragm 4 changes its axial position in the axial direction in which the outer peripheral surface and the outer peripheral surface of the second mounting member 3 are in contact with each other by changing the position of the portion that is folded back at the lowest position. Deforms while changing the range.
Here, when the first mounting member 2 and the second mounting member 3 are relatively displaced in the axial direction, the axial position of the folded portion of the diaphragm 4 is the same position over the entire circumference. Become. When the first mounting member 2 and the second mounting member 3 are relatively displaced in the radial direction, the position of the folded portion of the diaphragm 4 in the axial direction is determined by the second mounting member 3. 1 The mounting member 2 is positioned at the uppermost portion in the portion farthest outward in the radial direction, and is positioned in the lowermost portion in the portion furthest away in the radial direction.
As described above, when the first mounting member 2 and the second mounting member 3 are relatively displaced in accordance with the input of vibration, the diaphragm 4 is elastically deformed and the internal air is compressed. Vibration is absorbed.

  As described above, according to the air spring 1 according to the present embodiment, the flat plate portion 23 of the first mounting member 2 is more radially outward than the protruding portion 24 fitted into the one end portion 4a of the diaphragm 4. The thick part 23a is located in the position. For this reason, an axial compressive force is applied to the air spring 1, and the force transmitted from the diaphragm 4 to the flat plate portion 23 when the outer peripheral surface on the one end 4 a side of the diaphragm 4 is abutted against the thick portion 23 a. It becomes possible to suppress the deformation of the flat plate portion 23, and durability can be improved. In addition, the entire flat plate portion 23 is not thickened, but is thickened only at a portion where the outer peripheral surface on the one end 4a side of the diaphragm 4 abuts, so that an increase in weight can be suppressed.

  Further, the flat plate portion 23 and the protruding portion 24 are formed of a single metal plate, and the thick portion 23a of the flat plate portion 23 is a bent portion 23c positioned at the radially outer end portion, and the radially outer end. The parts are connected to each other via a bent part 23c, and two flat parts 23d that are overlapped with each other are provided. For this reason, it is possible to prevent the leakage of air in the air chamber 5 through the connecting portion between the flat plate portion 23 and the protruding portion 24.

  The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, in the above embodiment, the configuration in which the flat plate portion 23 and the projecting portion 24 are formed by press molding from a single metal plate is not limited to such an embodiment, but may be integrally formed by casting, The structure which connects the flat part and protrusion part which are separate bodies by welding may be sufficient.
Moreover, in the said embodiment, although the thickness of the thin part 23b showed the structure which is half the thickness of the thick part 23a, it is not restricted to such an aspect, The thickness of the thin part 23b and the thick part 23a About can be changed arbitrarily.

  In addition, it is possible to replace the constituent elements in the above-described embodiments with known constituent elements in a timely manner without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Air spring 2 1st attachment member 3 2nd attachment member 4 Diaphragm 4a One end part 4b Other end part 5 Air chamber 23 Flat plate part 23a Thick part 23b Thin part 23c Bending part 23d Flat part 24 Projection part

Claims (2)

A first mounting member coupled to one of the vibration generating unit and the vibration receiving unit, and a second mounting member coupled to the other;
A cylindrical diaphragm with one end attached to the first attachment member and the other end attached to the second attachment member;
An air spring in which an air chamber is defined between the first mounting member, the second mounting member, and the diaphragm,
The first mounting member includes a flat plate portion, and a cylindrical protruding portion that protrudes from the flat plate portion toward the air chamber and is fitted into one end portion of the diaphragm.
The flat plate portion includes a thick portion positioned on the outer side in the radial direction than the protruding portion, and a thin portion positioned on the inner side in the radial direction than the protruding portion.   The flat plate portion and the protruding portion are formed of a single metal plate, and the thick portion of the flat plate portion is a bent portion positioned at the outer end portion in the radial direction and the outer end portions in the radial direction are the same. The air spring according to claim 1, further comprising two flat portions that are connected to each other through the bent portions and overlap each other.

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