JPH08312709A - Orifice structure - Google Patents

Abstract

PURPOSE: To provide an orifice structure in which the size in the longitudinal direction of a orifice can be stably obtained, and the size in the longitudinal direction of the orifice can be easily changed. CONSTITUTION: A plate-like first member 8 provided with a projecting part 11 whose outer periphery is polygonal is superimposed on a plate-like second member 9 provided with a recessed part 13 to be fitted to the projecting part 11 of the first member 8, a vertical through hole 14 is formed on this first member 8, and an approximately C-shaped groove 15 whose one end is communicated with the through hole 14 is formed on the superimposed surface 10 to the second member 9. A vertical through hole 16 so opening as to face the groove 15 formed on the first member 8 is formed on the second member 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an orifice structure suitable for application to a fluid damping device for damping kinetic energy by the flow resistance of working fluid.

[0002]

2. Description of the Related Art In general, a fluid damping device is provided with an orifice for giving a flow resistance to a working fluid, and a damping force corresponding to a pressure difference of the working fluid before and after passing through the orifice is obtained. Therefore, by increasing the longitudinal dimension of the orifice to increase the flow resistance,
A large damping force can be obtained.

For this reason, in JP-A-60-40843, an annular recess is formed in one of a pair of superposed plate members by bending, and a through hole communicating with the annular recess is formed in these plate members. A technique has been proposed in which an orifice is constituted by the bent annular concave portion and the through hole to obtain an orifice having a long dimension in the longitudinal direction.

[0004]

However, in the above-mentioned conventional example, there is no particular consideration for the alignment between the pair of plate members to be superposed, and as a result, the dimension of the orifice in the longitudinal direction varies. May occur.
If the size of the orifice in the longitudinal direction is different, the damping force is different, and a stable damping force cannot be obtained.

The present invention has been devised in view of such a conventional situation, and an object thereof is to provide an orifice structure in which the longitudinal dimension of the orifice can be stably obtained. Another object is to provide an orifice structure in which the size of the orifice in the longitudinal direction can be easily changed.

[0006]

SUMMARY OF THE INVENTION Therefore, according to the present invention, a plate-shaped first member having a polygonal convex portion on its outer periphery is provided, and a plate-shaped first member having a concave portion fitted to the convex portion of the first member is provided. The upper and lower through holes are formed in either one of the first member and the second member while overlapping with the two members, and one end portion communicates with the through hole on the overlapping surface with the other member. While the substantially C-shaped groove is formed, upper and lower through-holes that open to face the groove are formed in either of the other members.

Further, the convex portion of the first member and the concave portion of the second member fitted into the convex portion are formed in a regular polygonal shape.

Further, a peripheral groove is provided on the outer periphery of the superposed first member and second member, and a seal ring is housed in the peripheral groove.

Further, the side surface of the circumferential groove is formed by a superposing surface of either one of the first member and the second member.

[0010]

By fitting the polygonal convex portion of the first member into the polygonal concave portion of the second member, the through hole and the substantially C-shaped groove formed in the first member and the second member respectively , An orifice having a predetermined longitudinal dimension is formed. At this time, the first member and the second member can be easily aligned with each other by fitting the polygonal protrusions and recesses. Therefore, there is no variation in the dimension of the orifice in the longitudinal direction, an orifice having a stable length can be obtained, and a stable damping force can be obtained.

Further, since the convex portion and the concave portion have a regular polygonal shape, the first member can be shifted in the rotational direction with respect to the second member to be superposed. As a result, the through holes formed in the first member and the second member approach or leave in the longitudinal direction of the orifice. As a result, the longitudinal dimension of the orifice can be easily changed.

Furthermore, by providing a peripheral groove on the outer circumference of the polymerized member and attaching a seal ring, it is possible to advantageously prevent leakage of the working fluid before and after the orifice.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a view showing an embodiment in which the orifice structure of the present invention is applied to a gas spring. In the figure, reference numeral 1 denotes a cylinder whose one end is sealed. The cylinder 1 is filled with a pressurized gas together with a small amount of lubricating oil. Two
Is a removable piston rod 4 extending through a guide member 3 provided at the other end of the cylinder 1, and 4 is a seal member. Reference numerals 5 and 6 are joint members attached to one end side of the cylinder 1 and the projecting end side of the piston rod, respectively, and are used for attaching the gas spring to a mating member.

A piston 7 to which the orifice structure of the present invention is applied is provided at the end of the piston rod 2 inside the cylinder 1.
Is installed. The piston 7 divides the inside of the cylinder 1 into upper and lower chambers 1a and 1b and is slidable in the cylinder 1.

The piston 7 is composed of a disc-shaped first member 8 and a second member 9 which are superposed on each other. As best shown in FIG. Is formed into a regular hexagonal convex portion 11, and the overlapping surface 12 of the second member 9 has a concave portion 1 that fits into the convex portion 11 of the first member 8.
3 is formed. Further, each of the first member 8 and the second member 9 is formed with central holes 8a and 9a which can be inserted into the reduced diameter portion 2a formed at the lower end portion of the piston rod 2.

Upper and lower through holes 14 are formed in the first member 8 with a predetermined size. This through hole 14 is formed at a position aligned with one of the vertices of a regular hexagon of the convex portion 11 in this embodiment. Further, on the overlapping surface 10, the through hole 14 is located at the regular hexagonal convex portion 11.
A substantially C-shaped groove 15 is formed at one end of which communicates. The through hole 14 is formed so as to be aligned with one of the vertices of the regular hexagon of the convex portion 11, and one end of the substantially C-shaped groove 15 is also formed near one vertex of the regular hexagon of the convex portion 11. The groove 15 ends near the other vertex of the regular hexagon of the convex portion 11. It should be noted that the depth and the groove width of the groove 15 are appropriately selected so as to obtain the desired flow resistance of the working fluid flowing in the groove 15.

The second member 9 is formed with upper and lower through holes 16 of a predetermined size, which are open to face the groove 15 formed in the first member 8. This through hole 16 is formed at a position aligned with one of the vertices of a regular hexagon of the recess 13 in this embodiment. In addition, the mating surface 1 of the second member 9
An annular step portion 18 is formed on the outer circumference on the second side.

Therefore, in the piston 7, when the convex portion 11 of the first member 8 is fitted in the concave portion 13 of the second member 9 and the two are superposed, the piston 7 passes through the groove 15 to the through hole 16 and then to the through hole 16. Orifice 17 leading to is formed, and also
The step portion 18 forms a circumferential groove 19 having the overlapping surface 10 of the first member 8 as one side wall. In this state, the piston 7 is attached to the piston rod 2 by inserting the central holes 8a and 9a into the reduced diameter portion 2a formed at the lower end portion of the piston rod 2 and caulking the piston rod 2 to seal it in the circumferential groove 19. The ring 21 is attached. The seal ring 21 is mounted in the circumferential groove 19 only when the first member 8 and the second member 9 are attached.
It is possible to easily mount the seal ring 21 by mounting it in the step portion 18 in advance before the superposition of and.

In such a structure, the piston rod 2 is inserted into and removed from the cylinder 1 so that the piston rod 2 is attached to the cylinder 1.
A reaction force (gas reaction force) of the pressurized gas corresponding to the volume that penetrates into the inside is generated, and with the withdrawal operation of the piston rod 2, through the orifice 17 that extends from the through hole 14 through the groove 15 to the through hole 16. As a result, a damping force is obtained by the flow resistance of the pressurized gas that is displaced and flow between the chambers 1a and 1b. Therefore, by connecting the joint members 5 and 6 of the gas spring between the two members that make relative movement, the relative kinetic energy between these two members is absorbed by the gas reaction force and attenuated by the flow resistance of the orifice 17. 2 and 3, the arrow indicates the direction of the flow of the pressurized gas from the side of the through hole 14 to the side of the through hole 16 via the groove 15. Since the direction of this flow changes depending on the moving direction of the piston 7, it may flow in the direction opposite to the direction of the arrow, but this orifice 17 functions similarly in any direction.

Here, the orifice 17 is formed by the through holes 14 and 16 and the groove 15 as described above, and this forms the regular hexagonal convex portion 11 of the first member 8 into the second portion.
Since it is formed by fitting into the regular hexagonal recess 13 of the member 9, the through hole 1 passes through the groove 15 and the through hole 1.
The lengthwise dimension of the orifice 17 up to 6 is accurate.

The lengthwise dimension of the orifice 17 can be changed by shifting the fitting position of the regular hexagonal convex portion 11 and the concave portion 13 in the rotational direction. That is, the length of the orifice 17 in the longitudinal direction is longest when the through hole 14 of the first member is at the position A and the through hole 16 of the second member 9 is at the position B in FIG. Is 5L. By shifting the fitting position of the regular hexagonal convex portion 11 and the concave portion 13 in the rotational direction, the position of the through hole 16 of the second member 9 with respect to the through hole 14 of the first member 8 is changed from the B position to the C position, and the D position. Position, E position, F
Can be moved to a position. Thereby, the length of the orifice 17 can be easily changed from 5L to 4L, 3L, 2L, and L. Further, by arranging the through hole 14 of the first member 8 and the through hole 16 of the second member 9 concentrically at the position A, the shortest orifice length can be obtained.

Therefore, by fitting the regular hexagonal convex portion 11 of the first member 8 into the regular hexagonal concave portion 13 of the second member 9, there is no dimensional variation in the longitudinal direction of the orifice 17 and a stable orifice is provided. The length is obtained. Further, by shifting the fitting position of the regular hexagonal convex portion 11 and the concave portion 13 in the rotational direction, the size of the orifice 17 in the longitudinal direction can be easily changed.

Further, by providing the peripheral groove 19 on the outer periphery of the polymerized member and attaching the seal ring 21 thereto, the leakage of the working fluid around the orifice 17 can be advantageously prevented.

Furthermore, since the side surface of the circumferential groove 19 is constituted by the superposing surface 10 of the first member 8, the circumferential groove 1
9 can be easily formed, and the seal ring 21 accommodated in the circumferential groove 19 can be preliminarily attached to the step portion 18, so that the seal ring 21 can be easily attached.

Although the embodiment has been described above with reference to the drawings, the specific structure is not limited to this embodiment,
Modifications can be made without departing from the spirit of the invention. For example, the convex portion 11 of the first member 8 and the concave portion 13 of the second member 9 that fits into the convex portion 11 are described as an example in which the shape is a regular hexagon, but other shapes such as a star shape may be used. The polygonal shape of the present invention needless to say need not have a pointed top, and also includes an elliptical shape.

[0027]

As described above in detail, according to the present invention, the plate-shaped first member having the convex portion having the polygonal outer periphery is provided with the concave portion fitted to the convex portion of the first member. The plate-shaped second member provided with the first member or the second member is formed with upper and lower through-holes, and one of the through-holes is formed on the overlapping surface with the other member. Forming a substantially C-shaped groove in which the ends of the two communicate with each other,
By forming the upper and lower through-holes opening facing the groove, there is no variation in the dimension of the orifice in the longitudinal direction,
A stable orifice length is obtained.

Further, since the convex portion of the first member and the concave portion of the second member fitted to the convex portion are regular polygonal shapes, the fitting position of the convex portion 11 and the concave portion 13 is shifted in the rotational direction. Thus, the size of the orifice in the longitudinal direction can be easily changed.

Further, by providing a circumferential groove on the outer circumference of the superposed first member and second member and accommodating the seal ring in the circumferential groove, it is possible to advantageously prevent the leakage of the working fluid before and after the orifice.

Further, by forming the side surface of the circumferential groove by the superposing surface of either one of the first member and the second member, the circumferential groove can be easily formed and the circumferential groove can be sealed. The ring can be attached easily.

[Brief description of drawings]

FIG. 1 is a sectional view of a gas spring to which an orifice structure of the present invention is applied.

FIG. 2 is a cross-sectional view showing an enlarged main part of FIG.

FIG. 3 is an explanatory view showing a first member and a second member in a disassembled state.

FIG. 4 is a drawing for explaining changes in the dimension of the orifice in the longitudinal direction.

[Explanation of symbols]

 8 1st member 9 2nd member 10 Stacking surface 11 Convex part 13 Recessed part 14,16 Through hole 15 Groove 17 Orifice 19 Circumferential groove 21 Seal ring

Claims (4)

[Claims] 1. A plate-shaped first member having a convex portion with a polygonal outer periphery is superposed on a plate-shaped second member having a concave portion that fits into the convex portion of the first member, Upper and lower through holes are formed in either one of the first member and the second member, and a substantially C-shaped groove whose one end communicates with the through hole is formed in the overlapping surface with the other member. On the other hand, an orifice structure characterized in that upper and lower through holes that open toward the groove are formed in either of the other members. 2. The orifice structure according to claim 1, wherein the convex portion of the first member and the concave portion of the second member fitted into the convex portion have a regular polygonal shape. 3. The orifice structure according to claim 1, wherein a circumferential groove is provided on the outer circumference of the polymerized first member and second member, and a seal ring is housed in the circumferential groove. . 4. The side surface of the circumferential groove is the first member or the second member.
The orifice structure according to claim 3, wherein the orifice structure is formed by a superposed surface of one of the members.