JP4912267B2 - Air spring - Google Patents

Description

  The present invention relates to an air spring used for truck automobiles, railway vehicles, and the like. More specifically, the present invention relates to a cylindrical rubber film, a large-diameter plate-like member hermetically joined to one end portion in the axial direction thereof, and a cylindrical rubber. A peripheral surface capable of rolling and guiding an inverted cylinder portion formed by folding the other end side with elastic deformation of the cylindrical rubber film. The present invention relates to an air spring formed on a piston.

  As this type of air spring, those disclosed in Patent Document 1 and Patent Document 2 are known. That is, as shown in FIG. 6, the air spring A includes a vertical cylindrical diaphragm (an example of a cylindrical rubber film) 1 that forms a wall portion of the first internal space S <b> 1 that is a gas chamber, and a vertical axis thereof. A disk-shaped upper plate (an example of a large-diameter plate member) 2 that is caulked and fixed to a large-diameter bead portion (an example of one end portion) 1A formed at the upper end of a diaphragm 1 having a center P, and a lower end of the diaphragm 1 And a piston 3 tightly fitted to a small-diameter bead portion (an example of the other end portion) 1B. The upper plate 2 includes mounting bolts 5 for mounting and fixing the upper plate 2 to the vehicle body frame F (see FIG. 4), and an air supply / discharge hole 4 into the diaphragm 1. The air supply / exhaust hole 4 is constituted by a metal pipe 12 or the like that is welded to the upper plate 2 and is hermetically fixed.

  The piston 3 has a straight cylinder-shaped main body that covers a small-diameter fitting cylinder portion 8 to which the lower end portion of the diaphragm 1 is externally fitted and a reverse cylinder portion 1C that is a portion where the lower side of the diaphragm 1 is folded inward. It consists of a piston main body 6 having a cylindrical portion 7 and a bottom plate portion 9 that closes the lower end portion of the main cylindrical portion 7, and has a common axis P with the diaphragm 1. The main cylinder part 7 and the fitting cylinder part 8 having a smaller diameter and disposed above are integrally formed by press molding, and are connected to the piston main body 6 by an annular step surface 10. Thus, the diaphragm 1 is pushed so as to cover the piston 3, and the outer peripheral surface 7A of the main cylinder portion 7 is configured to be able to roll and guide the inverted cylinder portion 1C. A large circular hole 11 is formed on the upper surface of the fitting cylinder portion 8, and the second internal space S <b> 2 inside the piston 3 communicates with the first space S <b> 1 through the large circular hole 11. Has been.

The bottom plate portion 9 is continuously air-tightly fitted to the lower end side of the main cylinder portion 7, and its lower end surface 9A is located at the same height level as the lower end 7t of the main cylinder portion 7 (the lower end surface 8A is the lower end 7t). It may be located below). Further, a mounting bolt 13 that is fixed integrally through the lower end surface 9A of the bottom plate portion 9 is provided.
JP 2005-36860 A JP 2007-51745 A

  The air spring A is devised to maintain a good fitting state between the diaphragm 1 and the piston 3. As shown in a partially enlarged view in FIG. 6, the small-diameter bead portion 1 </ b> B of the diaphragm 1 moves upward from the fitting cylinder portion 8 at the upper end portion of the fitting cylinder portion 8 in the piston 3 and easily comes out. In order to avoid this, the bulging ring portion 8A bulging in the outer diameter direction is integrally formed.

  The overhanging bulging ring portion 8A cannot be created by general press molding (such as deep drawing) that forms the fitting tube portion 8, and is therefore formed by adding another process such as a rotary press facility. Yes. However, the molding process in the separate process is special and has a high processing cost. Moreover, since the production of the bulging ring portion 8A is not a process that can be performed anywhere, there is a difficulty in that the number of contractors is limited.

  The purpose of the present invention is to revise the structure and production method of the bulging ring part at the front end of the fitting cylinder part and to devise a piston that can reduce the cost while maintaining the function of preventing the cylindrical rubber film from coming off. Realized and provides a more streamlined air spring.

The invention according to claim 1 includes a cylindrical rubber film 1, a large-diameter plate-like member 2 that is hermetically joined to one end 1 </ b> A of the axial center P direction of the cylindrical rubber film 1, and the axial direction P of the cylindrical rubber film 1. A circumferential surface having a piston 3 hermetically joined to the other end portion 1B and capable of rolling and guiding a reverse cylinder portion 1C formed by folding the other end portion 1B side with elastic deformation of the cylindrical rubber film 1 In the air spring 7A is formed in the piston 3,
The piston 3, the other end 1B is fitting cylinder 8 to be hermetically bonded is formed integrally Rutotomoni, the tip portion 8S of the fitting tube 8 has a portion 13 projecting radially outward direction A retaining member R is integrally mounted, and an annular upper wall portion 8a is formed on the distal end portion 8S .

  According to a second aspect of the present invention, in the air spring according to the first aspect, the retaining member R is formed in a ring shape made of a synthetic resin material and is bonded to the tip portion 8S. It is what.

According to a third aspect of the present invention, in the air spring of the first aspect, the tip end portion 8S of the fitting tube portion 8 is formed in an annular shape, and is formed in the ring-shaped retaining member R made of a light alloy. The retaining member R is inserted into the fitting cylinder portion 8 by fitting the inner circumferential portion 14 into the inner circumferential portion 11 of the annular upper wall portion 8a or by fitting with an adhesive. It is characterized by being integrated.

  According to the invention of claim 1, a separate retaining member is required, but special processing such as a rotary press process that requires high processing cost and extra manufacturing time can be omitted. The cost and manufacturing efficiency of the piston can be improved. As a result, by reviewing the structure and creation method of the bulging ring part at the tip of the fitting cylinder part, we have realized a piston that can reduce the cost while maintaining the function of preventing the cylindrical rubber film from coming off. A more streamlined air spring can be provided.

  According to the second aspect of the present invention, since the retaining member is made of synthetic resin and integrated with the fitting cylinder portion by bonding, an air spring that is easy to process and light in weight and excellent in productivity can be realized.

  If the retaining member is made of a light alloy as in the invention of claim 3, it is possible to provide an air spring having a piston with sufficient strength while being relatively light.

  Embodiments of an air spring according to the present invention will be described below with reference to the drawings. 1 is a cross-sectional view of an air spring according to the first embodiment, FIG. 2 is an enlarged view of a piston, FIG. 3 is a cross-sectional view of a main part showing a mounting structure of a headband ring, and FIG. 4 is a front view showing an example of use of the air spring. 5 is a cross-sectional view showing a headband ring according to Embodiment 2, and FIG. 6 is a cross-sectional view showing a conventional air spring.

[Example 1]
FIG. 4 shows an air spring A provided between a body frame F and an axle side of a truck (which may be a railway vehicle, a bus, etc.). That is, the air spring A (Embodiment 1) is arranged between the mounting plate 23 of the vehicle body frame F that supports the passage portion 22 of the vehicle body 21 and the axle 24. Incidentally, 25 is a tire, 26 is a tire house, and C is a left and right center of the vehicle body.

  As shown in FIG. 1, the air spring A according to the first embodiment is a conventional air spring described with reference to FIG. 6 except that the configuration of the fitting cylinder portion 8 in the piston 3 and the shape of the lower portion of the piston 3 are different. It is assumed that the same parts are denoted by the same reference numerals and the description thereof is made.

  Now, the main difference from that of FIG. 6 is that, instead of the configuration in which the bulging ring portion 8A is formed at the upper end portion of the fitting tube portion 8, as shown in FIGS. The headband ring (an example of a retaining member) R made of a synthetic resin material is fitted and bonded to the upper end (tip portion) 8S of the fitting cylinder portion 8 having the shape described above. The fitting tube portion 8 is formed in a tapered tube shape that is slightly tapered (upwardly narrowed) due to a draft angle by press molding.

A headband ring (also referred to as a piston cap) R includes a bulging outer peripheral portion (an example of a “protruding portion in the radially outward direction”) 13 that covers the upper end portion of the outer peripheral surface of the fitting cylinder portion 8 in a close state, and a large circular hole. (Example of inner peripheral portion) An inner peripheral portion 14 fitted into 11, a flange portion 15 formed to extend radially outward from a lower end portion of the inner peripheral portion 14, and an upper end portion and an inner portion of the bulging outer peripheral portion 13 It is comprised in the cyclic | annular thing which has the ring upper wall part 16 which connects and integrates the upper end part of the surrounding part 14 in the state along the upper surface of the cyclic | annular upper wall part 8a of the fitting cylinder part 8. FIG.

  The protrusion amount (protrusion width) d of the flange portion 15 to the outside of the diameter is set to a relatively small value such that the large circular hole 11 can be forced through from the top to the bottom mainly by deformation of the flange portion 15. . When the headband ring R is mounted on the fitting cylinder portion 8, it is firmly integrated by fitting with an adhesive applied between the two, and the small diameter bead portion 1B is prevented from coming off well. It is possible to demonstrate the function. The adhesive is preferably applied to all the joint surfaces between the headband ring R and the fitting cylinder portion 8, but may be applied only to the inner surface of the bulging outer peripheral portion 13 and the lower surface of the ring upper wall portion 16. . The first internal space S1 and the second internal space S2 are communicated with each other through a circular hole 17 of the headband ring R.

  Further, another difference between the air spring A according to the first embodiment and the air spring of FIG. 6 is the bottom plate portion 9 of the piston 3, and its lower end surface 9 </ b> A is positioned below the lower end 7 t of the main cylinder portion 7. That is. This is a difference due to the shape matching the actual mounting structure. Further, the aspect ratio of the piston body 6 may be different.

[Example 2]
As shown in FIG. 5, the upper structure of the piston 3 may be a structure in which a headband ring R made of an aluminum alloy (an example of a light alloy) is integrally attached to the upper end portion 8 </ b> S of the fitting cylinder portion 8. The headband ring R according to the second embodiment includes a bulging outer peripheral portion (an example of a “protruding portion in the radially outward direction”) 13 that covers the upper end portion of the outer peripheral surface of the fitting cylinder portion 8 in close contact with the large circular hole 11. The inner peripheral part 14 to be internally fitted, the upper end part of the bulging outer peripheral part 13 and the upper end part of the inner peripheral part 14 are connected and integrated in a state along the upper surface of the annular upper wall part 8a of the fitting cylinder part 8. It is comprised by the cyclic | annular thing which has the ring upper wall part 16. As shown in FIG. For the purpose of inserting the large circular hole 11, the flange portion 15 which is made of resin is omitted.

  When mounting the headband ring R to the distal end portion 8S of the fitting cylinder portion 8, the inner peripheral portion 14 can be mounted by press-fitting into the large circular hole 11, or only means for bonding, or press-fitting and bonding It is good to select and set appropriately from the means for performing both of the above.

[Another Example]
The headband ring R can be made of various materials such as hard rubber, stainless steel, steel plate, and ceramic. The shape of the retaining member R is such that the bulging outer peripheral portion 13 is intermittently formed in the circumferential direction so that it has a substantially gear shape when viewed in the axial direction, or the bulging outer peripheral portion 13 and the ring upper wall portion 16. It is also possible to use a retaining member R made of only.

  As described above, the headband ring R made of a separate member is retrofitted to replace the conventional bulging ring portion 8A at the upper end portion 8S of the fitting tube portion 8, so a separate headband ring R is required. However, since the rotary press process, which requires high processing cost and extra manufacturing time, can be omitted, the cost and manufacturing efficiency of the piston can be improved as a whole, and a more rational air spring can be provided. Has succeeded. If the headband ring R is made of synthetic resin and integrated with the fitting tube portion 8 by adhesion, the air spring A that is easy to process and light in weight and excellent in productivity can be realized. Moreover, if the headband ring R is made of a light alloy, an air spring having a piston with sufficient strength while being relatively light can be provided.

Sectional view showing an air spring (Example 1) 1 is an exploded sectional view showing a piston of the air spring of FIG. The expanded sectional view of the principal part which shows the fitting cylinder part of the piston of FIG. Front view showing usage example of air spring Sectional drawing of the principal part which shows another structure of a piston fitting cylinder part (Example 2) Sectional view showing structure of conventional air spring and piston upper part

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical rubber film 1A One end part 1B Other end part 1C Reversing cylinder part 2 Large diameter plate-shaped member 3 Piston 7A Circumferential surface 8 Fitting cylinder part 8S Tip part
8a Annular upper wall part 11 Inner peripheral part of tip part 13 A part protruding radially outward A Air spring P Shaft center R Retaining member

Claims (3)

A cylindrical rubber film, a large-diameter plate-like member that is airtightly joined to one end portion in the axial direction of the cylindrical rubber film, and a piston that is airtightly joined to the other end portion in the axial direction of the cylindrical rubber film, An air spring formed on the piston with a circumferential surface capable of rolling and guiding an inverted tube portion formed by folding the other end side with elastic deformation of the cylindrical rubber film,
The piston, the other end portion is formed in the fitting tube portions integrally is hermetically joined Rutotomoni, the distal end of the fitting tube, retaining member integrally has a portion projecting radially outward direction And an air spring having an annular upper wall portion formed on the distal end portion and directed radially inward .   The air spring according to claim 1, wherein the retaining member is formed in a ring shape made of a synthetic resin material and bonded to the tip portion. The front end portion of the fitting tube portion is formed in an annular shape, and an inner peripheral portion formed in the ring-shaped retaining member made of a light alloy is press-fitted into the inner peripheral portion of the annular upper wall portion , Alternatively, the air spring according to claim 1, wherein the retaining member is integrated with the fitting tube portion by press-fitting with an adhesive.

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