JP2006234068A - Single cylinder-shaped hydraulic damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure airtightness of an air spring formed by an air chamber when making no use of welding on a damper body because it is made of aluminum. <P>SOLUTION: In the single cylinder-shaped hydraulic damper 1 of which the cylinder body 11 is made of an aluminum material, the lower end of a piston pipe 22 which airtightly connects the lower end of a rolling diaphragm 21 with the upper end of the rolling diaphragm 21 is airtightly connected with the lower end of a protector 23 by arranging a seal member 3, arranged with a gap S outside of the cylinder body communicating with the atmosphere. Further, a bending section 23a formed on the upper end of the protector is supported by a crimped end 11a as the upper end of the cylinder body, and connection to the gap in the air chamber 2 is blocked by arranging a seal member 4 between the bending section 23a and crimped end 11a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement of a single-cylinder hydraulic shock absorber with an air spring used for a vehicle suspension device.

  Various proposals have conventionally been made for hydraulic shock absorbers used in vehicle suspension devices. In recent years, for example, as disclosed in Patent Document 1, a shock absorber main body constituting a hydraulic shock absorber is a single unit. Proposals have been made to have an air chamber as an air spring on the upper end side of the shock absorber body while being cylindrical.

  That is, in the proposal disclosed in Patent Document 1, the air chamber has a rolling diaphragm, and one end side of the rolling diaphragm is connected to the piston rod side constituting the shock absorber body in an airtight state. On the other hand, the other end side is connected to the cylinder body side constituting the shock absorber main body in an airtight state, thereby ensuring the airtightness in the air chamber.

  At this time, in the proposal disclosed in Patent Document 1, the lower end portion of the piston pipe that connects the lower end portion of the rolling diaphragm in an airtight state is arranged so as to have a gap communicating with the atmosphere outside the cylinder body. It is assumed that an airtight state is realized by being welded in the vicinity of the lower end portion of the protector, and an airtight state is realized by welding the upper end portion of the protector to the outer periphery of the cylinder body.

Therefore, in the proposal disclosed in Patent Document 1, the shock absorber body is configured as a single cylinder type that encloses a high-pressure gas, and is a hydraulic shock absorber that includes a double cylinder type shock absorber body that encloses atmospheric pressure. Compared to the above, it is possible to obtain a desired air spring effect by an air chamber in which airtightness is ensured while improving the damping action, which is suitable for use in a suspension device in a vehicle.
Japanese Patent Laying-Open No. 2004-332747 (Claims Claims 1, Paragraphs 0018, 0025 to 0028, FIG. 1)

  By the way, although the proposal disclosed in the above-mentioned Patent Document 1 does not have a particular problem, when it is attempted to significantly reduce the weight of the shock absorber body by using an aluminum material, it is difficult to realize the shock absorber body. There is a risk of being pointed out.

  That is, in the hydraulic shock absorber disclosed in Patent Document 1 described above, the upper end of the protector is welded to the upper end of the cylinder body in order to ensure airtightness inside the rolling diaphragm. When it is formed of an aluminum material, generally speaking, welding is not preferable because it causes a decrease in strength of the aluminum material.

  Therefore, in view of this, there is a single cylinder type hydraulic shock absorber in which the cylinder body constituting the shock absorber body is made of an aluminum material and has an air chamber that is an air spring connected to the cylinder body made of the aluminum material. Therefore, in the realization, it would be desirable to propose measures that do not rely on welding.

  The present invention was devised in view of such a current situation, and the object of the present invention is to achieve airtightness in an air chamber as an air spring even when welding cannot be used due to so-called aluminization of the shock absorber body. This is to provide a single-cylinder hydraulic shock absorber with an air spring that is optimal for use in a vehicle suspension device.

  In order to achieve the above object, the structure of the single cylinder type hydraulic shock absorber according to the present invention is basically as follows. The cylinder body constituting the shock absorber body formed in the single cylinder type is made of an aluminum material, and the shock absorber The air chamber has an air chamber on the upper end side of the main body, and the air chamber connects one end side of the rolling diaphragm in an airtight state to the piston rod side of the shock absorber main body that protrudes and retracts from the cylinder body, while the other end side In the single cylinder type hydraulic shock absorber that is connected to the cylinder body in an airtight state, a lower end portion of the piston pipe that connects the lower end portion of the rolling diaphragm to the upper end portion in an airtight state has a gap that leads to the atmosphere outside the cylinder body. It is connected to the lower end of the protector distributed in an airtight state under the distribution of the seal member, while the bent portion formed at the upper end of the protector is Upcoming while being carried on the crimping end, the Haizai sealing member between the bent portion and the caulked end formed by blocking the communication into the gap within the air chamber.

  More specifically, the protector is made of an aluminum material, and the seal member is accommodated in an annular groove formed on the outer periphery of the lower end portion of the protector, and the outer periphery of the seal member is the lower end portion of the piston pipe. Suppose you are in close contact.

  Therefore, in the present invention, since the cylinder body constituting the shock absorber body is basically made of an aluminum material, the weight of the shock absorber body can be reduced as well as the air chamber. When the protector to be formed is made of an aluminum material, the weight of the shock absorber body can be further reduced.

  And since the lower end part of the piston pipe which comprises an air chamber, and the lower end part of the protector which consists of aluminum materials are connected under the intervention of a seal member, an airtight state can be realized without welding between both. Therefore, there is no need to worry about the decrease in mechanical strength due to welding in the aluminum material.

  At this time, since a gap communicating with the so-called external atmosphere is formed between the protector and the cylinder body, heat from the cylinder body can be dissipated into the atmosphere through this gap.

  Since the seal member is held on the outer periphery of the protector on the inner side as compared with the piston pipe, the seal member can be easily held as compared with the case where the seal member is held on the inner periphery of the piston pipe. .

  Further, since the seal member is disposed between the crimping end that is the upper end of the cylinder body and the bent portion of the protector carried by the cylinder body, air leakage from the inside of the air chamber is prevented by this seal member, and the airtightness in the air chamber is prevented. Sex is guaranteed.

  As a result, according to the present invention, in a single cylinder type hydraulic shock absorber with an air spring, even when welding cannot be used due to so-called aluminization in the shock absorber body, the airtightness in the air chamber can be ensured. Become.

  Hereinafter, the present invention will be described based on the illustrated embodiment. As shown in FIG. 1, a single cylinder type hydraulic shock absorber according to the present invention basically includes a cylinder body constituting a shock absorber body 1. 11 is made of an aluminum material, and has an air chamber 2 as an air spring on the upper end side of the shock absorber body 1.

  The air chamber 2 is, as shown, a rolling diaphragm 21 made of an elastic material such as rubber, a piston pipe 22 having a predetermined mechanical strength such as an iron pipe, and a predetermined mechanical strength while being made of an aluminum material. And a protector 23 having a predetermined diameter, and a predetermined spring force is exhibited by expansion and contraction of the rolling diaphragm 21.

  At this time, the rolling diaphragm 21 forms a so-called slack portion so that the lower half side is wound inward while being formed in a cylindrical shape having a larger diameter than the piston pipe 22 and the like which will be described later. Although not shown in detail, the one end side which is the upper end side in the figure is connected to the upper end side of the piston rod 12 in the shock absorber body 1 in an airtight state by any means. In the drawing, the other end portion that is folded inward, which is the lower end side, is connected to the outer periphery of the upper end portion of the piston pipe 22 in an airtight state by using, for example, a fastening band 21a.

  Therefore, the rolling diaphragm 21 defines an air chamber A inside a so-called rubber curtain, and the air chamber A has a volume increased or decreased by expansion / contraction of the rubber diaphragm, that is, the rolling diaphragm 21. At this time, a predetermined air spring force is exhibited.

  In many cases, the piston pipe 22 is formed in a cylindrical shape that tends to converge on the lower end side. The lower end portion of the piston pipe 22 is connected to the upper end portion of the rolling diaphragm 21 in an airtight state while the lower end portion is the protector 23. It is supposed that it will be connected to the lower end part of an under airtight state.

  The protector 23 has a diameter smaller than that of the piston pipe 22 and a large diameter with respect to the cylinder body 11. The protector 23 is formed in a cylindrical shape similar to the cylinder body 11 and has a bent portion 23 a at the upper end. It is said to have.

  Incidentally, the protector 23 is made of an aluminum material. In this case, the protector 23 is preferably cast. By casting, the protector 23 can be easily formed to a thickness having a predetermined mechanical strength.

  The protector 23 has a bent portion 23 a at the upper end. The bent portion 23 a is supported on the caulking end 11 a which is the upper end of the cylinder body 11, so that the lower end side is suspended outside the cylinder body 11. At this time, it is assumed that a gap S communicating with the atmosphere appears between the lower end side and the cylinder body 11, and heat from the cylinder body 11 is diffused to the outside atmosphere through the gap S. .

  By the way, as for the bent portion 23a, as shown in the figure, it is assumed that the upper end portion of the protector 23 is bent inward to form a so-called flange-like shape. This is because it is not preferable that the portion, that is, the bent portion 23a is formed as a separate body and connected to the upper end of the protector 23 by welding, and the bent portion is formed in a flange shape. This is because the pressing state against the seal member 4 can be made uniform in the circumferential direction if the 23a contacts and presses the seal member 4 described later.

  Further, the lower end portion of the piston pipe 22 and the lower end portion of the protector 23 are connected in an airtight state so that the lower end portion of the protector 23 is press-fitted inside the lower end portion of the piston pipe 22. In the meantime, a predetermined airtight state is realized in the presence of the seal member 3.

  At this time, as shown in FIG. 2, the seal member 3 is formed in a plurality of annular grooves 23 b having a concave cross section formed on the outer periphery of the lower end portion of the protector 23 while being made into a plurality to facilitate airtightness. The outer circumferences of the piston pipes 22 are in close contact with the inner circumference of the lower end portion of the piston pipe 22.

  At this time, from the viewpoint of the function of the seal member 3, the seal member 3 may be held on the piston pipe 22 side instead of being illustrated.

  However, in order to hold the seal member 3 on the piston pipe 22 side, it is necessary to realize an optimum shape for holding the seal member 3 by bending the lower end portion of the piston pipe 22 or the like. Considering this, it can be said that it is preferable that the seal member 3 is held on the protector 23 side as shown in the drawing.

  The seal member 4 is disposed between the crimping end 11a as the upper end of the cylinder body 11 and the bent portion 23a of the protector 23. The function of the seal member 4 is between the crimping end 11a as the upper end of the cylinder body 11 and the protector 23. This prevents air leakage between the bent portion 23a and the air in the air chamber 2 from flowing out into the atmosphere via the gap S between the cylinder body 11 and the protector 23.

  Therefore, from this, the seal member 4 may be formed in an arbitrary shape as long as it exhibits a predetermined function.

  In the single cylinder type hydraulic shock absorber according to the present invention formed as described above, the shock absorber main body 1 is configured in a single cylinder type while enabling weight reduction, so that it can be used for a suspension device in a vehicle. However, it is not necessary to cause an unnecessarily large increase in weight. On the other hand, the damping action at the time of expansion / contraction operation of the shock absorber body 1 in which the piston rod body 12 protrudes and retracts with respect to the cylinder body 11 is a double cylinder type that encloses atmospheric pressure. Compared to the case of the shock absorber body, it is improved depending on the high-pressure gas to be sealed, and the piston chamber 12 is retracted relative to the cylinder body 11. Thus, the air chamber A defined by the rolling diaphragm 21 changes the volume of the rod volume in the piston rod body 12 that appears and disappears with respect to the cylinder body 11, and this air chamber During volume change in the rolling diaphragm 21 to expand and contract, so that the predetermined air spring effect is exhibited.

It is a front view showing a single cylinder type hydraulic shock absorber according to the present invention in a partially broken view. It is a fragmentary sectional front view which expands and shows the principal part in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shock absorber body 2 Air chamber 3, 4 Seal member 11 Cylinder body 11a Caulking end 12 Piston rod 21 Rolling diaphragm 22 Piston pipe 23 Protector 23a Bending part 23b Annular groove S Gap

Claims (3)

The cylinder body constituting the shock absorber body formed in a single cylinder type is made of aluminum, and has an air chamber on the upper end side of the shock absorber body, and the air chamber has one end side of the rolling diaphragm as the cylinder body. In the single cylinder type hydraulic shock absorber, the lower end of the rolling diaphragm is connected to the upper end of the shock absorber body, which is connected to the piston rod side of the shock absorber body that is protruded and retracted while the other end is connected to the cylinder body in an airtight state. While the lower end portion of the piston pipe to be connected to the airtight state is connected to the lower end portion of the protector disposed with a gap communicating with the outside of the cylinder body in the air, the seal member is connected in an airtight state, The bent portion formed at the upper end of the protector is carried by the crimping end that is the upper end of the cylinder body, and the seal member disposed between the bent portion and the crimping end is an air Single cylinder type hydraulic shock absorber, characterized in that formed by blocking the communication into the gaps in the Nba The single cylinder type hydraulic shock absorber according to claim 1, wherein the protector is made of an aluminum material. The single cylinder type hydraulic shock absorber according to claim 1, wherein a seal member is accommodated in an annular groove formed on an outer periphery of a lower end portion of the protector, and an outer periphery of the seal member is in close contact with the lower end portion of the piston pipe.

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