JP6731841B2 - Axial spring - Google Patents

Description

The present invention relates to a shaft spring suitable for large construction machines, large ships, especially railroad vehicles, and more specifically, a main shaft, an outer cylinder arranged in a state of surrounding the main shaft when viewed from the axial direction of the main shaft, and a plurality of outer cylinders. An elastic portion interposed between the main shaft and the outer cylinder in a state where the elastic material layer and one or more hard material walls are alternately laminated in the radial inward and outward directions with respect to the shaft center. The present invention relates to a shaft spring.

In a railcar, for example, this type of shaft spring is interposed between the bogie frame and the axle-side member in order to absorb and mitigate the snake's behavior and the shock of vertical movement. That is, the shaft spring as an example of the shaft box supporting device is such that the two hard material walls and the three rubber layers are concentric with each other between the main shaft and the outer cylinder arranged around the main shaft, and in the radial direction. Many of them have a structure in which they are alternately laminated.

As for the tendency of axle springs for railway vehicles, it is desirable that the elastic layer has a soft spring constant in consideration of ride comfort, but consider the withstand load when a large weight is applied, such as when the vehicle is over capacity. It is desirable that the spring constant is hard. In order to satisfy such conflicting requirements, conventionally, as disclosed in Patent Document 1 (see FIGS. 3 and 6) and Patent Document 2, the outer peripheral surface of the main shaft, the elastic layer, and the inner peripheral surface of the outer cylinder are disclosed. It was an inclined type axial spring in which the surfaces were tilted in the same direction.

By adopting the inclined type, a so-called progressive characteristic that the spring constant increases as the cushion stroke increases, a so-called progressive characteristic can be obtained when the cushion stroke is small, and a good riding feeling can be obtained due to the soft spring constant, and the cushion stroke is large. Occasionally, a shaft spring was realized that exerts tension even with a large load due to a hard spring constant.

However, in order to further improve the riding comfort of the vehicle, there is a demand for lower vertical rigidity, that is, lower spring constant. In the inclined type axial spring, first, it is possible to decrease the spring constant by making the angle of inclination with respect to the vertical axis thereof gentle (standing), but if so, the maximum load resistance will also decrease. It's not convenient. Therefore, it is conceivable that the angle of inclination is made gentler and the maximum load resistance is secured while the elastic portion is made large, but this means is inconvenient because the shaft spring itself becomes large.

JP, 2014-073726, A JP, 2005-169313, A

An object of the present invention is to provide a shaft spring which can improve the ride comfort without lowering the maximum load resistance by reasonably softening the spring constant at the initial stage or the first half of the cushion stroke by further improving the structure.

The invention according to claim 1 includes a main shaft 1, an outer cylinder 2 arranged in a state of surrounding the main shaft 1 when viewed from the direction of the axis P of the main shaft 1, and a plurality of elastic material layers 4a, 4b, 4c. Or, in a state where a plurality of hard material walls 5a and 5b are alternately laminated in the radial inward and outward directions with respect to the axis P, an elastic portion 3 interposed between the main shaft 1 and the outer cylinder 2, In a shaft spring having
The outer peripheral surface 1a of the main shaft 1 and the inner peripheral surface 2a of the outer cylinder 2 are formed into conical surfaces inclined at the same first angle θ1 with respect to the axis P, and the hard material walls 5a and 5b are formed. The second angle θ2 inclined with respect to the axis P is set to be smaller than the first angle θ1.

The invention according to claim 2 provides the shaft spring according to claim 1,
The outer cylinder 2 is arranged to be closer to the tapered side of the outer peripheral surface 1a in the direction of the axis P with respect to the main shaft 1.

The invention according to claim 3 is the shaft spring according to claim 1 or 2, wherein
The elastic portion 3 includes three elastic material layers 4a, 4b and 4c inside and outside and two hard material walls 5a and 5b inside and outside, and the second angle θ2 and the outside of the inner hard material wall 5a. Each of the second angles θ2 of the hard material wall 5b is set to an angle smaller than the first angle θ1.

The invention according to claim 4 is the axial spring according to any one of claims 1 to 3,
The range in which the second angle θ2 is smaller than the first angle θ1 is set to 1.5 to 7.5 degrees.

The invention according to claim 5 is the shaft spring according to any one of claims 1 to 4,
The outer peripheral surface 1a includes a tapered front end surface 9 having a third angle θ3 larger than the first angle θ1 and a tapered proximal end surface 10 having a fourth angle θ4 smaller than the first angle θ1. And the average angle of the outer peripheral surface 1a is set to the first angle θ1.

According to the invention of claim 1, in the elastic portion having the laminated rubber structure, the inclination angle of the hard material wall sandwiched by the elastic material layers is made smaller than the inclination angle of the outer peripheral surface of the main shaft or the inner peripheral surface of the outer cylinder. Therefore, the degree of increase in the elastic displacement of the elastic part with respect to the load acting on the shaft spring is compared with the conventional one in which the inclination angle of the hard material wall is equal to the inclination angle of the outer peripheral surface of the spindle or the inner peripheral surface of the outer cylinder. Can be loosened. Since the inclination angles of the outer peripheral surface of the main shaft and the inner peripheral surface of the outer cylinder are the same as the conventional ones, the elastic deformation amount at the maximum load can be kept unchanged.
As a result, it is possible to provide a shaft spring in which the spring constant can be reasonably softened in the early stage of the cushion stroke or in the first half by further structural improvement, and the riding comfort can be improved without reducing the maximum load resistance.

According to a second aspect of the present invention, the outer cylinder is a shaft spring that is biased toward the tapered side of the outer peripheral surface of the main shaft in the axial direction with respect to the main shaft. With the axial spring provided with the elastic material layer and the two hard material walls inside and outside, the function and effect of the invention of claim 1 can be obtained more clearly.

According to the fourth aspect of the invention, the softening of the spring constant is set within an appropriate range, and the effect of the first aspect of the invention can be appropriately obtained. That is, if the range of the second angle θ2 smaller than the first angle θ1 is less than 1.5 degrees, the effect of softening the spring constant can hardly be expected, and if it exceeds 7.5 degrees, the spring constant is softened. Because it will be excessive.

According to the invention of claim 5, the conical outer peripheral surface of the main shaft is inclined in three steps, for example, the angle of the tip end is larger and the angle of the base end is smaller than the middle part. Even in such a case, the average angle thereof may be the same as that of the inner peripheral surface of the outer cylinder. Therefore, there is an advantage that the shape variations of the spindle can be enriched.

The top view of the axial spring by Embodiment 1. Sectional drawing which cut|disconnected the axial spring of FIG. 1 by "front-axis center P-right". Diagram showing the relationship graph between load and displacement The top view of the axial spring by Embodiment 2. Sectional drawing which cut|disconnected the axial spring of FIG. 4 by "front-axis center P-right".

Hereinafter, an embodiment of a shaft spring according to the present invention will be described as a railcar shaft spring with reference to the drawings.

[Embodiment 1]
As shown in FIGS. 1 and 2, a railcar shaft spring (hereinafter, simply referred to as shaft spring) A has a main shaft 1 and a longitudinal shaft center that is the same as (or may be substantially the same as) the main shaft 1. The outer cylinder 2 having P and the elastic portion 3 interposed between the main shaft 1 and the outer cylinder 2 are configured. The elastic portion 3 has a laminated rubber structure in which three elastic layers 4 and two intermediate hard cylinders 5 are alternately laminated radially inward and outward with the axis P being concentric (or almost concentric). , Between the main shaft 1 and the outer cylinder 2.

Here, in FIG. 1 (FIG. 4), the direction of a line segment that connects the punched holes 6 and 7 formed in the elastic layer 4 and the axis P to the left and right, and the pair formed at the lower end of the main shaft 1 The direction connecting the screw holes 1g and 1g is defined as front and rear. Then, in FIG. 2 (FIG. 5), with respect to the spindle 1 having the axis P, the tapered side from the shape of the spindle 1 is defined as the upper side, and the original expansion side (anti-converged side) is defined as the lower side.

As shown in FIGS. 1 and 2, the main shaft 1 is made of metal, and includes a conical upper portion 1A having an inclined outer peripheral surface 1a formed of an upper conical surface, and a large outer peripheral surface 1b having a maximum diameter. It is formed in a tubular shaft having a flange portion 1B having a lower outer diameter of the conical upper portion 1A and a lower straight body portion 1C having a small outer peripheral surface 1c having a small diameter and continuing to the lower side of the flange portion 1B. There is. The inclined outer peripheral surface 1a is inclined with respect to the axis P at a first angle θ1.

A hollow portion 1d having an upper end opening centering on the axis P is formed in the cone upper portion 1A, and the hollow portion 1d is extended to a vertically intermediate position of the lower straight body portion 1C. In the lower straight body portion 1C, there are formed small diameter vertical holes 1f having an axis P and opening at the lower end, and screw holes 1g, 1g formed on both sides of the small diameter vertical holes 1f. ing. The small-diameter vertical hole 1f and the screw holes 1g, 1g are opened in the funnel-shaped bottom surface 1e of the hollow portion 1d.

As shown in FIGS. 1 and 2, the outer cylinder 2 is made of metal, and has a slanted inner peripheral surface 2a formed of a downwardly-spreading conical surface, and a fitting inner peripheral surface continuing to the upper side of the slanted inner peripheral surface 2a. It has a surface 2b and an annular upper end surface 2c, and is formed into a tubular member having a vertical cross-section of a V shape. The outer cylinder 2 having the shaft center P is arranged closer to the upper side (the tapered side) with respect to the main shaft 1. That is, the outer cylinder 2 is moved upward so that the height level of the upper end of the main shaft 1 and the height level of the lower end of the outer cylinder 2 are substantially the same.

The inclination angle of the inclined inner peripheral surface 2a with respect to the axis P is set to the same first angle θ1 as that of the inclined outer peripheral surface 1a of the main shaft 1. That is, the inclined inner peripheral surface 2a and the inclined outer peripheral surface 1a are parallel to each other. The first angle θ1 is set to, for example, 10 degrees (or 10 degrees ±5 degrees), but may be another angle.
In FIG. 2, the auxiliary line a of the inclined outer peripheral surface 1a and the auxiliary line b of the inclined inner peripheral surface 2a are indicated by arrow marks to be parallel to each other.

As shown in FIGS. 1 and 2, the elastic portion 3 is an annular elastic layer 4 composed of three rubber layers (an example of an elastic material layer) 4a, 4b, 4c, and two annular rings made of metal or sheet metal. (Example of hard material wall) By interposing intermediate hard cylinders 5 made up of 5a and 5b in the radial inward and outward directions with respect to the axis P, they are interposed between the main shaft 1 and the outer cylinder 2. It is configured. The elastic layer 4 has an inner rubber layer 4a, a middle rubber layer 4b, and an outer rubber layer 4c from the inside in the radial direction. The inner rubber layer 4a has a thin film portion 4h that covers most of the upper surface (not shown) of the main shaft 1 from the radially outer side. The upper intermediate rigid cylinder 5 has an inner annular ring 5a and an outer annular ring 5b from the inside in the radial direction.

The elastic layer 4 and the intermediate hard cylinder 5 are inclined with respect to the axis P in the same direction as the inclined outer peripheral surface 1a of the main shaft 1 and the inclined inner peripheral surface 2a of the outer cylinder 2. The second angle θ2 that is inclined with respect to the axis P of the inner and outer annular wheels 5a and 5b is set to be smaller than the first angle θ1.
The second angle θ2 is set to 7.5 degrees when the first angle θ1 is 10 degrees, for example. In addition, (θ1-1.5 degrees)≧θ2≧(θ1-7.5 degrees), preferably (θ1-2.5 degrees)≧θ2≧(θ1-4.5 degrees), or other angles (Θ1>θ2) may be used.
In FIG. 2, the auxiliary line c of the inner annular ring 5a and the auxiliary line d of the outer annular ring 5b are indicated by double arrow marks to be parallel to each other.

The inner rubber layer 4a, the middle rubber layer 4b, and the outer rubber layer 4c have the same thickness (or substantially the same thickness) at the lower end portions (thickness in the radial direction). In FIG. 2, assuming that a line segment connecting the uppermost recessed portions on the lower end surfaces of the rubber layers 4a to 4c is an auxiliary line e, the widths of the rubber layers 4a to 4c on the auxiliary line e are the same or It is configured to be almost the same.

Since the two annular wheels 5a, 5b are inclined at an upright angle with respect to the inclined outer peripheral surface 1a and the inclined inner peripheral surface 2a, the thickness of the upper end portion of the outer rubber layer 4c <the thickness of the upper end portion of the middle rubber layer 4b <inner The thickness of the upper end portion of the rubber layer 4a is set. Further, the inner annular ring 5a is moved to the upper side (the tapered side) with respect to the main shaft 1, the outer annular ring 5b is moved to the upper side (the tapered side) with respect to the inner annular ring 5a, and the outer cylinder 2 is It is moved to the upper side (the tapered side) with respect to the outer annular ring 5b.

As shown in FIGS. 1 and 2, each of the outer rubber layer 4c and the middle rubber layer 4b has a pair of holes 6 and 7 arranged in the left-right direction in a vertically penetrating state. As shown in FIG. 1, when the widthwise ends (circumferential ends with respect to the axis P) of the outer and inner holes 6, 7 are connected and auxiliary lines f and g passing through the axis P are drawn, The width angles of the holes 6 and 7 are aligned at the same sixth angle θ6. The one auxiliary line g also passes through the centers of the pair of mounting screw portions 8 of the outer cylinder 2. The sixth angle θ6 is divided into equal front and rear angles. Each of the vent holes 6 and 7 has a width close to the radial width of the rubber layers 4c and 4b, leaving the rubber film 4g in the radial direction, in order to prevent rusting of the outer cylinder 2 and the intermediate hard cylinders 5 and 5. doing.

When a load is applied to the outer cylinder 2, the elastic portion 3 elastically deforms and suspends in a direction in which the outer cylinder 2 is lowered with respect to the main shaft 1. Since the elastic portion 3 sandwiched between the inclined outer peripheral surface 1a and the inclined inner peripheral surface 2a is subjected to a compressive load in addition to a shear load, the spring of the elastic portion 3 increases as the load in the axial center P direction increases. A non-linear characteristic in which the constant increases, that is, a so-called progressive characteristic can be obtained.

Since the two annular wheels 5a, 5b are set at an angle upright from the inclined outer peripheral surface 1a and the inclined inner peripheral surface 2a, when a load in a direction in which the outer cylinder 2 and the main shaft 1 approach each other in the axial center P direction, Compared with the elastic portion of the conventional structure (the two annular wheels 5a, 5b and the inclined outer peripheral surface 1a and the inclined inner peripheral surface 2a are all at the same angle), the maximum load condition as the elastic portion 3 is not changed, It is possible to moderately increase the spring constant of the elastic portion 3 as a whole.

The elastic layer 4 is elastically displaced by both the shear resistance and the compression resistance against a load in the direction of the axis P, but the middle rubber layer 4b has the conventional structure (the inclination angle θ2 of the annular wheels 5a and 5b). Has a greater proportion of shear resistance than that of the inclined inner circumferential surface 2a), and the spring constant increases as the load increases, that is, the progressive characteristic becomes gentle. The inner rubber layer 4a and the outer rubber layer 4c are also affected by the fact that the inclination angle (θ2) on one side is raised, so that the progressive characteristics become gentler than those of the conventional structure, although not as much as the middle rubber layer 4b. Since the inner and outer inclination angles (θ1) of the elastic portion 3 are the same as the conventional one, the progressive characteristic becomes larger than the conventional one when the load increases in the latter half of the stroke or near the limit. Therefore, the maximum displacement amount of the elastic portion 3 at the time of maximum load can be kept the same as the conventional one.

FIG. 3 shows an example of a load-displacement amount graph showing the relationship between the displacement amount of the elastic portion 3 and the load in the axial center P direction of the shaft spring. Line (a) shows a conventional axial spring in which the inclination angles of the annular wheels 5a and 5b are the same as those of the inclined outer peripheral surface 1a and the inclined inner peripheral surface 2a, and the line (b) shows the load of the axial spring A according to the present application. -The graph of the amount of displacement is shown. From the graph of FIG. 3, the conventional shaft spring and the shaft spring of the first embodiment have the same displacement amount at the maximum load, but the displacement amount at a certain load is larger in the shaft spring of the first embodiment. That is, it can be seen that the spring constant is small.

[Embodiment 2]
The shaft spring A may have the structure shown in FIGS. 4 and 5. The axial spring A of the second embodiment is the same as the axial spring A of the first embodiment except that the shape of the main shaft 1 and the circumferential lengths (θ7) of the holes 6, 7 are different, and The same reference numerals are given and the explanation is omitted. The outer peripheral surface 1a of the main shaft 1 and the inner peripheral surface 2a of the outer cylinder 2 are formed to have conical surfaces (9, 11, 2a) inclined in the same direction with respect to the axis P.

As shown in FIGS. 4 and 5, the main shaft 1 has a tapered tip surface 9 having a third angle θ3 larger than the first angle θ1 and a tip having a fourth angle θ4 smaller than the first angle θ1. It has a tapered proximal end surface 10 and a tapered intermediate surface 11 having a fifth angle θ5 which is slightly smaller than the first angle θ1, and has an inclined outer peripheral surface 1a having a plurality of steps. The average angle of the three inclined outer peripheral surfaces 1a is set to be the same as or substantially the same as the first angle θ1.

That is, the arranging direction of the elastic portion 3 formed over the main shaft 1 and the outer cylinder 2 (extending direction in the radial direction with respect to the axis P) is indicated by an arrow Z, and the elastic layer on the tapered front end surface 9 is shown. 4 is w9, the width length of the elastic layer 4 at the tapered proximal end face 10 to the arrow Z is w10, and the width length of the elastic layer 4 at the tapered intermediate face 11 to the arrow Z is w11. In such a case, the equation 1 is expressed as θ3×w9+θ4×w10+θ5×w11≈θ1×(w9+w10+w11).

The arrangement direction Z of the elastic portion 3 is defined by an angle with respect to an axis P of an upper line segment connecting the upper surfaces of the three rubber layers 4a, 4b, 4c radially inward and outward, and an underline connecting the lower surfaces radially inward and outward. It is an average angle with respect to the axis P of the minute.
The upper line segment averages the line segments connecting the lowest recessed points on the upper surfaces of the three rubber layers 4a, 4b, 4c, or the lowest recessed points on the inner and outer ends of each upper surface. It can be defined as a line segment connecting the virtual locations.
The underlined line is a line segment that connects the uppermost recessed portions on the lower surfaces of the three rubber layers 4a, 4b, 4c (see auxiliary line e in FIG. 2), or the inner and outer ends of each lower surface. Can be defined as a line segment connecting averaged virtual points).
Then, as shown in FIG. 5, the substantial thickness of the elastic layer 4 integrated with each of the surfaces 9, 10, 11 of the outer peripheral surface 1a is defined as the width length w9, w10, w11 with respect to the arrow Z. ing.

Further, in the case of the axial spring A of FIG. 5, since θ1<θ3, θ1>θ4, θ1>θ5, the formula 1 is represented by the formula 2: (θ3-θ1)×w9≈(θ1-θ4)×w10+(θ1 It can also be expressed as −θ5)×w11. For example, when θ1=10 degrees, θ3=33.5 degrees, θ4=0 degrees, θ5=7.5 degrees, w9=6, w10=11, w11=12, (33.5-10)×6. =141, (10-0)×11=110, and (10-7.5)×12=30, so 141≈140(110+30).

The width lengths w9, w10, w11 of the elastic layer 4 are substantial width lengths corresponding to the outer peripheral surfaces 9, 10, 11 in consideration of the inclination of the elastic portion 3. That is, the three inclined outer peripheral surfaces 9, 10, 11 forming the inclined outer peripheral surface 1a of the main shaft 1 are configured such that their arithmetic average angles are equal to or substantially equal to θ1.
The inclination angle of the tapered intermediate surface 10 with respect to the axis P is θ1, and the surfaces inclined with respect to the first angle θ1 are the tapered front end surface 9 (θ3) and the tapered base end surface 10 (θ4). ) And the inclined outer peripheral surface 1a which is only two.

[Another embodiment]
The degree of displacement (amount of displacement) of the outer cylinder 2 with respect to the main shaft 1 in the direction of the axis P may be other than those shown in FIGS. A shaft spring having two elastic layers 4 and one intermediate hard cylinder 5 or a structure having four or more elastic layers 4 and three or more intermediate hard cylinders 5 is possible.

DESCRIPTION OF SYMBOLS 1 main shaft 1a outer peripheral surface 2 outer cylinder 2a inner peripheral surface 3 elastic part 4 elastic layers 4a to 4c elastic material layer 5 intermediate hard cylinders 5a, 5b hard material wall 9 constricted front end surface 10 constricted proximal end surface P axis center θ1 First angle θ2 Second angle θ3 Third angle θ4 Fourth angle

Claims (5)

Spindle and
An outer cylinder arranged in a state of surrounding the main shaft in the axial direction of the main shaft,
In a state in which a plurality of elastic material layers and one or a plurality of hard material walls are alternately laminated in the radial inner and outer directions with respect to the axis, an elastic portion interposed between the main shaft and the outer cylinder,
A shaft spring having:
An outer peripheral surface of the main shaft and an inner peripheral surface of the outer cylinder are formed into conical surfaces inclined at the same first angle with respect to the shaft center, and are inclined with respect to the shaft center of the hard material wall. A shaft spring in which two angles are set to be smaller than the first angle. The shaft spring according to claim 1, wherein the outer cylinder is arranged closer to the tapered side of the outer peripheral surface in the direction of the axis with respect to the main shaft. The elastic part includes three elastic material layers inside and outside and two hard material walls inside and outside, and both the second angle of the inner hard material wall and the second angle of the outer hard material wall. The shaft spring according to claim 1, wherein the shaft spring is set to an angle smaller than the first angle. The axial spring according to claim 1, wherein a range of the second angle smaller than the first angle is set to 1.5 to 7.5 degrees. The outer peripheral surface has a tapered distal end surface having a third angle larger than the first angle and a tapered proximal end surface having a fourth angle smaller than the first angle. The axial spring according to any one of claims 1 to 4, wherein an average angle is set to the first angle.

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