JP4048015B2 - Air spring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air spring device, and more particularly to an improvement of an air spring device that is disposed between a vehicle body side and an axle side in a vehicle and absorbs vibrations in the vertical direction or the horizontal direction.
[0002]
[Prior art]
For example, there have been various proposals so far for an air spring device that is arranged between a vehicle body side and an axle side in a vehicle and absorbs vibrations in the vertical direction or the horizontal direction.
[0003]
Among them, for example, in the proposal shown in FIG. 3, the upper member 1 made of a rigid body, the lower member 2 made of a rigid body, and the upper and lower ends made of an elastic body are fixed to the upper member 1 and the lower member 2. The air chamber A, which is a sealed space, is defined by the diaphragm 4 that is connected in an airtight state using the fastening ring 3 that is a member.
[0004]
Incidentally, this air spring device is illustrated as being interposed on the outer periphery of the hydraulic shock absorber 5, and the so-called upper end portion of the upper member 1 is hydraulically buffered under an appropriate sealing structure via the connecting member 11. It is assumed that the lower end portion 2 of the lower member 2 is connected to a cylinder body 52 that also constitutes the hydraulic shock absorber 5 under an appropriate sealing structure. .
[0005]
Therefore, in the air spring device shown in FIG. 3, as long as the airtightness between the so-called upper and lower ends of the diaphragm 4 and the upper member 1 and the lower member 2 adjacent to each other is ensured, the upper member For example, the diaphragm 4 is deformed and the volume of the air chamber A is changed during the relative movement between the first member 1 and the lower member 2, and a predetermined air spring effect can be exhibited.
[0006]
[Problems to be solved by the invention]
However, in the air spring device described above, it may be pointed out that the predetermined air spring effect cannot be expected permanently.
[0007]
That is, in the above-described air spring device, the airtightness between the upper and lower ends of the diaphragm 4 and the upper member 1 and the lower member 2 is tightened by the fixing member interposed on the outer periphery of the upper and lower ends of the diaphragm 4. It is secured by tightening the attached ring 3.
[0008]
At this time, the diaphragm 4 has a so-called slack portion 4a on the lower end side in order to ensure a volume change in the air chamber A. In order to secure this slack portion 4a, the lower end portion is lifted from below. In this state, the lower member 2 is connected to the lower ring 2 by using the tightening ring 3.
[0009]
As a result, for example, as shown by a solid line in FIG. 4, the diaphragm 4 is further lifted from a state where there is a slight slack portion 4 a at the lower end side of the diaphragm 4 as shown by a virtual line in FIG. 4. When the slack portion 4a is almost eliminated, the bent portion 4b appears in the vicinity of the lower end portion of the diaphragm 4, that is, in a portion adjacent to the edge portion of the fastening ring 3.
[0010]
Then, stress is concentrated on the bent portion 4b, that is, the edge of the tightening ring 3 is adjacent to the bent portion 4b, so that a shearing force is applied. 4b is fatigued, and finally, the diaphragm 4 is broken from the bent portion 4b.
[0011]
As a result, in the above-described air spring device, air leakage due to breakage in the diaphragm 4 is caused, and it becomes impossible to expect a predetermined air spring effect.
[0012]
The present invention was created in view of the above-mentioned circumstances, and the object of the present invention is optimal for enabling the permanent use without fear of air leakage due to the fracture in the diaphragm. It is providing the air spring apparatus which becomes.
[0013]
[Means for Solving the Problems]
To achieve the above object, the means of the air spring device according to the present invention includes a cylindrical upper member made of a rigid body, a bottomed cylindrical lower member also made of a rigid body, and an upper member and a lower portion, respectively. In an air spring device in which an air chamber is defined by a diaphragm connected to a member through a fixing member, a stepped portion in which an upper end portion of the lower member is bent inward, and a reduced diameter portion that rises continuously with the stepped portion A curved portion that curves continuously to the outer peripheral side continuously from the reduced diameter portion, and a folded portion that is continuously folded and formed to line up with the reduced diameter portion. And the lower end portion of the diaphragm is connected to the reduced diameter portion by the diameter expanding action of the diameter expanding ring arranged on the inner peripheral side while contacting the inner periphery of the reduced diameter portion, And the lower end of the diaphragm A curved portion continuous is to said that there were secondary Align the curved portion and the folded portion of the.
[0015]
In the above-described configuration, a well-known structure may be selected for connecting the upper end of the diaphragm to the outer periphery of the upper member in an airtight state, but a cap that also serves as a fixing member may be used.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
The air spring device of the present invention includes a cylindrical upper member 1 made of a rigid body, a bottomed cylindrical lower member 2 made of a rigid body, and upper and lower ends connected to the upper member 1 and the lower member 2 via fixing members, respectively. The air chamber A is partitioned by the diaphragm 4 connected in this manner.
And the step part 2a which the upper end part of the said lower member 2 was bend | folded inside, the diameter reducing part 2b which stands | starts up following this step part 2a, and the curved part 2c which curves to this outer peripheral side continuously from this diameter reducing part 2b And a folded portion 2d formed so as to be continuous with the curved portion 2c and lined up with the reduced diameter portion 2b, and with a folded portion 2d whose tip is in contact with the stepped portion 2a, and the lower end portion of the diaphragm 4 is While being in contact with the inner periphery of the reduced diameter portion 2b, it is connected to the reduced diameter portion 2b by the diameter expanding action of the diameter expanding ring 7 disposed on the inner periphery side, and is connected to the lower end portion of the diaphragm 4 A continuous curved portion 4c is subordinate to the curved portion 2c and the folded portion 2d.
This will be described in more detail below.
[0017]
The diaphragm 4 is deformed during the relative movement between the upper member 1 and the lower member 2, for example, and the volume of the air chamber A is changed to exhibit a predetermined air spring effect.
[0018]
However, unlike the conventional air spring device shown in FIG. 3, the illustrated air spring device is not interposed on the outer periphery of the hydraulic shock absorber, and although not shown, for example, the vehicle body side and the axle side of the vehicle When arranged between the two, the hydraulic shock absorber is arranged separately.
[0019]
That is, first, the upper member 1 is in the illustrated embodiment and is formed in a wide-mouthed short cylinder shape, and the inner periphery of the upper end portion of the diaphragm 4 is adjacent to the outer periphery thereof.
[0020]
At this time, although not shown in the figure, it is assumed that a shallow annular fixing groove is formed on the outer periphery of the upper member 1, and the upper end of the diaphragm 4 is adjacent to cover the annular fixing groove, When a cap 6 also serving as a fixing member, which will be described later, is interposed, the upper end portion of the diaphragm 4 is embedded in the annular fixing groove. It is said that airtightness is secured.
[0021]
By the way, the cap 6 that also serves as the fixing member is formed in a cap shape having a wide section and a shallow square U shape with a downward cross section. Is allowed.
[0022]
Further, the cap 6 forms a tightening ring portion 6c so as to project annularly toward the inner peripheral side of the skirt portion 6b with the lower end side being a substantially cylindrical skirt portion 6b. The structure also serves as a ring.
[0023]
Therefore, in this cap 6, the skirt portion 6b, that is, the tightening ring portion 6c is adjacent to the outer periphery of the upper end portion of the diaphragm 4 adjacent to the outer periphery of the upper member 1, and the outer peripheral side is removed. The upper end of the diaphragm 4 can be connected to the outer periphery of the upper member 1 in an airtight state, and the upper end opening of the upper member 1 can be closed with the lid 6a.
[0024]
In the case of the cap 6, since the space between the inner periphery of the upper end portion of the diaphragm 4 and the outer periphery of the upper member 1 is covered, it is possible to prevent in advance the occurrence of a problem that dust or mud is clogged between the two. There is an advantage to become.
[0025]
Next, the lower member 2 is in the illustrated embodiment, and is formed in a cylindrical shape whose cross section is an upward bullet, and the upper end is an open end so that the inside is part of the air chamber A. On the other hand, it is assumed that the lower end is closed by a bottom lid 21 that has been pressure-deformed.
[0026]
In the lower member 2, as shown in FIG. 2, the diameter-reduced portion 2b whose upper end portion is smaller in diameter than the lower portion via the stepped portion 2a and the diameter-reduced portion 2b are continuous. The curved portion 2c is curved to the outer peripheral side, and the folded portion 2d is formed so as to be folded back so as to be aligned with the reduced diameter portion 2b.
[0027]
Incidentally, the so-called tip of the folded portion 2d is in contact with the above-described stepped portion 2a, and the tip 4 of the folded portion 2d becomes a so-called edge so that the diaphragm 4 is not damaged.
[0028]
On the other hand, the diaphragm 4 is made of an elastic body, that is, rubber having an appropriate thickness, and is deformed by a well-known measure such as vulcanization molding, for example, when no load is applied as shown in FIG. Not formed to be able to maintain normal.
[0029]
At this time, the diaphragm 4 is assumed to have a curved portion 4c that comes to be subordinate to the curved portion 2c in the lower member 2 as well as the slack portion 4a.
[0030]
That is, the diaphragm 4 is connected to the reduced diameter portion 2b by the enlarged diameter ring 7 as a fixing member adjacent to the inner periphery of the diaphragm 4 while the lower end portion is adjacent to the inner periphery of the reduced diameter portion 2b. The curved portion 4c continuous to the lower end portion of the diaphragm 4 is set to be adjacent to the curved portion 2c, and the lower end side continuous to the curved portion 4c of the diaphragm 4 is set to be adjacent to the folded portion 2d.
[0031]
At this time, the curved portion 2c of the lower member 2, the diaphragm 4 adjacent herein, for example, in order not to generate easily bent portion cause stress concentration, such as a portion indicated by reference numeral 4b in FIG. 4 described above In addition, it is set to have a so-called roundness.
[0032]
Therefore, the curved portion 2c of the lower member 2 is in a state of being accompanied by the curved portion 4c of the diaphragm 4, and therefore, when the lower end side of the diaphragm 4 is largely lifted upward as shown in FIG. Of course, the curved portion 4c of the diaphragm 4 allows this, and at this time, the curved portion 4c is in a so-called extended state.
[0033]
Therefore, as long as the stress is not concentrated on the curved portion 4c, there is no fear that the diaphragm 4 is broken from the curved portion 4c even if the curved portion 4c is repeatedly expanded and contracted. Become.
[0034]
Incidentally, the above-described enlarged diameter ring 7 as the fixing member has any configuration as long as the predetermined airtight state between the lower member 2 and the diaphragm 4 can be maintained during the diameter expansion, that is, during the pressure deformation. May be set.
[0035]
For connecting the lower end portion of the diaphragm 4 to the lower member 2 in an airtight state by the diameter expanding ring 7, the upper member 1 has an annular fixing groove, and the end of the diaphragm 4 is in the annular fixing groove. Of course, the configuration in which the portion is embedded may be adopted in the same manner.
[0036]
As described above, when the air spring device according to the present invention is disposed between the vehicle body side and the axle side of the vehicle, for example, the air spring device is not interposed in the outer periphery of the hydraulic shock absorber and is separated. Although it is supposed to be distributed, instead of this, although not shown, it may be interposed on the outer periphery of the hydraulic shock absorber.
[0037]
Further, when the air spring device according to the present invention is disposed in a vehicle, the upper member 1 is connected to the vehicle body side of the vehicle, while the piston rod in the hydraulic shock absorber is connected to the bottom lid 2a constituting the lower member 2. The upper ends of the body may be connected to each other. In this case, it is needless to say that the same effects as described above can be expected including the above-described case.
[0038]
According to the present invention, a cylindrical upper member made of a rigid body, a bottomed cylindrical lower member made of a rigid body, and a diaphragm having upper and lower ends connected to the upper member and the lower member through fixing members, respectively. In the air spring device that divides the air chamber, a stepped portion in which the upper end portion of the lower member is bent inward, a reduced diameter portion that rises continuously to the stepped portion, and an outer peripheral side continuous to the reduced diameter portion. And a bent portion that is formed so as to be continuously lined up with the reduced diameter portion and that has a tip abutted against the stepped portion, and a lower end portion of the diaphragm is formed. A curved portion connected to the reduced diameter portion by a diameter expanding action of a diameter expanding ring disposed on the inner peripheral side while contacting the inner periphery of the reduced diameter portion and continuing to the lower end portion of the diaphragm The above curved part and folded part are Because it was not by-Align, when a state where the lower end side of the diaphragm is lifted largely upward, that of course the curved portion in the diaphragm to allow this, this time, is ready for the curved portion so extended, as long as the In this case, no stress is concentrated on the curved portion. Therefore, even if the curved portion is repeatedly expanded and contracted, there is no fear of the diaphragm breaking from the curved portion.
In addition, since the diaphragm is connected to the reduced diameter portion by the diameter expanding action of the diameter expanding ring adjacent to the inner periphery while the lower end portion is adjacent to the inner periphery of the reduced diameter portion, the lower end portion of the diaphragm Can be maintained in an airtight state by being pressure-deformed to the inner periphery of the reduced diameter portion.
Furthermore, since the tip of the folded portion is in contact with the stepped portion, it is possible to reliably prevent the tip of the folded portion from becoming a so-called edge and damaging the diaphragm.
[0039]
As a result, according to the present invention, there is an advantage that there is no fear of air leakage due to breakage in the diaphragm, and permanent use is possible.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an air spring device according to the present invention.
FIG. 2 is a partially enlarged longitudinal sectional view showing a state where a lower end portion of the diaphragm shown in FIG.
FIG. 3 is a partial vertical cross-sectional view showing a conventional air spring device interposed in the outer periphery of a hydraulic shock absorber.
FIG. 4 is a partially enlarged longitudinal sectional view showing a state in which a lower end portion of a diaphragm is fastened to an outer periphery of a lower member by a fastening ring in a conventional air spring device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Upper member 2 Lower member 2a Step part 2b Reduced diameter part 2c Curved part 2d Folded part 4 Diaphragm 4a Slack part 4c Curved part 6 Cap 6a which also serves as a fixing member Lid part 6b Skirt part 6c Ring 21 Bottom lid A Air chamber

Claims (1)

An air chamber is defined by a cylindrical upper member made of a rigid body, a bottomed cylindrical lower member made of a rigid body, and a diaphragm in which upper and lower ends are connected to the upper member and the lower member via fixing members, respectively. In the air spring device, the step portion in which the upper end portion of the lower member is bent inward, the reduced diameter portion that rises continuously to the step portion, and the curved portion that curves to the outer peripheral side continuously from the reduced diameter portion, The bent portion is formed so as to be continuously lined up with the reduced-diameter portion continuously with the curved portion, and the folded end portion is in contact with the stepped portion, and the lower end portion of the diaphragm is connected to the reduced-diameter portion. The curved portion connected to the reduced diameter portion by the diameter expanding action of the diameter expanding ring disposed on the inner peripheral side while contacting the inner periphery, and a curved portion continuing to the lower end portion of the diaphragm is connected to the curved portion. characterized in that there were secondary Align the folded portion That the air spring device.

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