JP6918406B2 - Leaf springs for railroad car bogies and bogies for railroad cars - Google Patents

Description

The present invention relates to a leaf spring for a railroad vehicle bogie and a bogie for a railroad vehicle.

As disclosed in Patent Document 1, leaf springs extending in the longitudinal direction of the vehicle are provided on the bogie frame, both ends of the leaf springs in the longitudinal direction of the vehicle are supported by axle boxes, and the bogie is provided by the central portion of the leaf springs in the longitudinal direction of the vehicle. Bogies for rolling stock that support the cross beams of the frame are known.

As an example, a leaf spring is configured by arranging a core layer between an upper layer and a lower layer made of FRP (fiber reinforced plastic). Further, as an example, the upper layer and the lower layer have a UD layer in which continuous fibers are oriented with the vehicle longitudinal direction as a single orientation direction. By using such a leaf spring, the side beam can be omitted to reduce the weight of the bogie frame, and the bogie assembly work can be simplified.

International Publication No. 2013/038763

The leaf spring is required to have excellent strength against a load in the vertical direction as its basic performance, but there is a possibility that a torsional load may be applied when the trolley is caught by a crane or the like. Further, in the leaf spring, when the crack is generated in the core layer so as to extend in the vertical direction, the crack may extend to the upper layer or the lower layer, the performance of the leaf spring may be deteriorated, and the life may be shortened.

Therefore, a first object of the present invention is to provide a leaf spring for a railroad vehicle bogie, which has excellent strength against a load in the vertical direction as a basic performance and also has a high strength against a torsional load.

Further, the present invention is to prevent deterioration of the performance and shortening of the life of a leaf spring for a railroad vehicle bogie in which a core layer is arranged between an upper layer and a lower layer made of FRP due to a crack generated in the core layer. Is the second purpose.

The leaf spring for a railroad vehicle bogie according to one aspect of the present invention is a leaf spring for a railroad vehicle bogie having at least one long FRP structure, and the FRP structure simply has a longitudinal direction of the leaf spring. A single orientation direction is a plurality of main UD sheets in which continuous fibers are oriented as one orientation direction, and a direction in which the continuous fibers are inclined at an angle in the range of 5 ° or more and 10 ° or less in the width direction of the leaf spring with respect to the longitudinal direction. With respect to a main UD sheet laminate in which a predetermined number of main UD sheets are laminated in the vertical direction among the plurality of main UD sheets, the sub The UD sheets are laminated in the leaf thickness direction of the leaf spring.

According to the above configuration, a predetermined number of long main UD sheets in which continuous fibers are oriented with the longitudinal direction of the leaf spring as a single orientation direction are laminated in the vertical direction by a main UD sheet laminate in the vertical direction. Excellent strength against load is obtained as basic performance. Further, a secondary UD sheet in which continuous fibers are oriented with a direction in which the leaf spring is inclined at an angle of 5 ° or more and 10 ° or less in the width direction of the leaf spring as a single orientation direction is provided as a leaf spring with respect to the main UD sheet laminate. By laminating in the plate thickness direction, high strength can be obtained even with a torsional load.

Further, the leaf spring for a railroad vehicle trolley according to another aspect of the present invention is a leaf spring for a railroad vehicle trolley having a pair of long FRP structures, and is a core layer and the leaf spring of the core layer. The upper layer, which is one of the pair of FRP structures, and the lower layer, which is laminated on the other side of the core layer in the plate thickness direction, are laminated on one side in the plate thickness direction. The upper layer and the lower layer include a UD layer in which continuous fibers are oriented with the longitudinal direction of the leaf spring as a single orientation direction, and the leaf spring in the UD layer on the core layer side of the UD layer. It has a blocking layer laminated in the plate thickness direction, and the blocking layer is inclined in an angle in the range of 40 ° or more and 50 ° or less on one side in the width direction of the leaf spring with respect to the longitudinal direction. The first continuous fiber is oriented, and the second continuous fiber is oriented in a direction in which the leaf spring is inclined at an angle in the range of 40 ° or more and 50 ° or less on the other side of the width direction of the leaf spring with respect to the longitudinal direction.

According to the above configuration, in the upper layer and the lower layer, the continuous fibers of the UD layer and the first continuous fibers and the second continuous fibers of the blocking layer can be crossed at a sufficient angle in the range of 40 ° or more and 50 ° or less. can. Therefore, when cracks occur in the vertical direction in the core layer, the cracks propagate in the vertical direction through the gaps between the continuous fibers of the UD layer, so that the leaf spring plate is formed on the UD layer on the core layer side of the UD layer. It can be blocked in advance in the blocking layer laminated in the thick direction.

According to the present invention, it is possible to provide a leaf spring for a railroad vehicle bogie, which has excellent strength against a load in the vertical direction as a basic performance and also has a high strength against a torsional load.

Further, according to the present invention, in a leaf spring for a railroad vehicle bogie in which a core layer is arranged between an upper layer and a lower layer made of FRP, it is possible to prevent deterioration of leaf spring performance and shortening of life due to cracks generated in the core layer. can.

It is a side view of the railroad vehicle bogie according to the embodiment. It is a perspective view of the leaf spring of FIG. It is an exploded view of the leaf spring of FIG. It is a vertical cross-sectional view seen from the longitudinal direction of the leaf spring of FIG. It is a figure which shows the state at the time of manufacturing of the upper layer of FIG. It is a perspective view which shows the prepreg laminated body which is pressurized and heated under reduced pressure.

Hereinafter, embodiments will be described with reference to the drawings.

FIG. 1 is a side view of the railroad vehicle bogie 1 according to the embodiment. As shown in FIG. 1, the railroad vehicle bogie 1 includes a bogie frame 3 that supports the vehicle body 50 of the railroad vehicle via an air spring 2 that serves as a secondary suspension. The bogie frame 3 includes cross beams 4 extending in the vehicle width direction to support the vehicle body 50, but does not include side beams extending in the vehicle longitudinal direction in the front-rear direction from both ends of the cross beams 4 in the vehicle width direction.

The air spring 2 is installed on the upper surface of the cross beam 4. A pair of axles 5 are arranged on both sides of the cross beam 4 in the vehicle longitudinal direction. Wheels 6 are fixed on both sides of the axle 5 in the vehicle width direction. Further, on both sides of the axle 5 in the vehicle width direction, a bearing 7 for rotatably supporting the axle 5 and a pair of axle boxes 8 for accommodating each of the bearings 7 are provided. Both ends of the cross beam 4 in the vehicle width direction are connected to a pair of axle boxes 8 by an axle beam type connecting mechanism 9.

A leaf spring 10 is bridged between the cross beam 4 and the axle box 8. The leaf spring 10 is arranged so as to extend in the longitudinal direction of the vehicle, and supports the cross beam 4 in a state where both ends 10c in the longitudinal direction of the vehicle are supported by the pair of axle boxes 8. The leaf spring 10 elastically supports both ends of the cross beam 4 in the vehicle width direction from below at the central portion 10a in the longitudinal direction. As a result, the leaf spring 10 has both the function of the primary suspension and the function of the conventional side beam.

In the present embodiment, a contact member 11 having an arc-shaped lower surface 11a when viewed from the vehicle width direction is provided below both ends of the cross beam 4 in the vehicle width direction, and the contact member 11 is centered in the longitudinal direction of the leaf spring 10. It is placed on the portion 10a from above and is in free contact with the central portion 10a. That is, the contact member 11 is in contact with the upper surface of the leaf spring 10 by a downward load due to gravity from the cross beam 4 without fixing the leaf spring 10 in the vertical direction.

A support member 12 is attached to the upper end of the axle box 8. Both ends 10c of the leaf spring 10 in the longitudinal direction are supported from below by the axle box 8 via the support member 12. Both ends 10c of the leaf spring 10 in the longitudinal direction are placed on the support member 12 from above and are in free contact with the upper surface of the support member 12 by a downward load from the leaf spring 10. As a result, both ends 10c of the leaf spring 10 in the longitudinal direction are supported by the pair of axle boxes 8 without being fixed to the pair of axle boxes 8.

FIG. 2 is a perspective view of the leaf spring 10 of FIG. As shown in FIGS. 1 and 2, of the leaf springs 10, the extending portion 10b located between the longitudinal central portion 10a and the longitudinal both end portions 10c is located at the longitudinal central portion 10a in a side view. The central portion 10a in the longitudinal direction of the leaf spring 10 is located below the both end portions 10c in the longitudinal direction of the leaf spring 10. That is, the leaf spring 10 is formed in a bow shape that is convex downward in the plate thickness (Z) direction of the leaf spring 10 as a whole when viewed from the side. Further, the leaf spring 10 is formed so that the wall thickness gradually increases from both end portions 10c in the longitudinal direction toward the center portion in the longitudinal direction.

FIG. 3 is an exploded view of the leaf spring 10 of FIG. The leaf spring 10 includes at least one (pair in this embodiment) long FRP structure. As shown in FIG. 3, specifically, the leaf spring 10 includes a core layer 17, an upper layer 15 which is one of a pair of FRP structures, and a lower layer 16 which is the other of the pair of FRP structures.

The core layer 17 extends in the longitudinal direction of the leaf spring 10. As an example, the core layer 17 is arranged at a position where at least a part thereof overlaps with the neutral axis of the leaf spring 10 in the side view. The core layer 17 has a laminated structure in which a plurality of layers 24 (here, a GFRP layer) extending in the longitudinal direction of the leaf spring 10 are laminated in the width (Y) direction of the leaf spring 10 (see FIG. 4).

In the present embodiment, the thickness (Z) direction dimension of the core layer 17 decreases from the center in the longitudinal direction toward both ends. As an example, the minimum thickness direction dimension of the core layer 17 is larger than the thickness direction dimension of the lower layer 16 and smaller than the thickness direction dimension of the upper layer 15. Further, the maximum thickness direction dimension of the core layer 17 is larger than the thickness direction dimension of the upper layer 15, and here, it is larger than three times the thickness direction dimension of the upper layer 15.

The upper layer 15 is laminated on one side (here, the upper side) of the leaf spring 10 of the core layer 17 in the plate thickness direction. The lower layer 16 is laminated on the other side (here, the lower side) of the core layer 17 in the plate thickness direction. The upper layer 15 and the lower layer 16 extend in the longitudinal direction of the leaf spring 10. In the present embodiment, the upper layer 15, the lower layer 16, and the core layer 17 continuously extend from one end to the other end in the longitudinal direction of the leaf spring 10.

The dimensions of the upper layer 15 and the lower layer 16 in the thickness direction are constant as an example. The thickness direction dimension of the upper layer 15 is larger than the thickness direction dimension of the lower layer 16. As an example, in the present embodiment, the thickness direction dimension of the upper layer 15 is larger than twice the thickness direction dimension of the lower layer 16. Further, the thickness direction dimension of the upper layer 15 and the lower layer 16 is smaller than the width direction dimension of the leaf spring 10.

The upper layer 15 is adhered to the upper surface of the core layer 17 by the adhesive layer 18, and the lower layer 16 is adhered to the lower surface of the core layer 17 by the adhesive layer 18. The adhesive layer 18 is made of an adhesive. The adhesive layer 18 contains a known adhesive. The adhesive contained in the adhesive layer 18 may be an acrylic adhesive, a polyurethane adhesive, or a reaction-curing resin adhesive such as a silicon resin adhesive, in addition to the epoxy adhesive.

The FRP structure included in the leaf spring 10 is made of carbon fiber reinforced plastic (CFRP) in this embodiment, but is not limited thereto. Other FRP structures included in the leaf spring 10 are glass fiber reinforced plastic (GFRP), glass fiber reinforced plastic (GMT), aramid fiber reinforced plastic (AFRP), boron fiber reinforced plastic (BFRP), and polyethylene fiber reinforced plastic (DFRP). ), Zylon (registered trademark) reinforced plastic (ZFRP) and the like. When CFRP is used, the carbon fiber as the continuous fiber (reinforcing fiber) may be either PAN-based or pitch-based.

When the upper layer 15 and the lower layer 16 are composed of an FRP structure, the materials of the continuous fibers included in the upper layer 15 and the lower layer 16 may be the same or different.

FIG. 4 is a vertical cross-sectional view of the leaf spring 10 as viewed from the longitudinal direction. FIG. 4 shows a partial cross section of each of the upper layer 15, the adhesive layer 18, and the core layer 17. The plurality of layers 24 in the core layer 17 are adhered with an adhesive. As shown in FIG. 4, an adhesive layer 19 is formed between the adjacent layers 24. The adhesive layer 19 extends in the longitudinal direction and the vertical direction of the leaf spring 10.

The core layer 17 may be integrally molded without using an adhesive. In this case, the core layer 17 does not have the adhesive layer 19.

The upper layer 15 and the lower layer 16 have a plurality of main UD sheets 20 and at least one sub UD sheet 21. The UD sheet referred to here refers to a fiber sheet in which continuous fibers functioning as reinforcing fibers in an FRP structure are oriented with substantially a predetermined direction as a single orientation direction.

In the main UD sheet 20, continuous fibers are oriented with the longitudinal direction of the leaf spring 10 as a single orientation direction. In the secondary UD sheet 21, continuous fibers are oriented with a direction in which the secondary UD sheet 21 is inclined at an angle in the range of 5 ° or more and 10 ° or less in the width direction of the leaf spring 10 with respect to the longitudinal direction of the leaf spring 10 as a single orientation direction. .. In the present embodiment, the at least one sub-UD sheet 21 described above includes a plurality of sub-UD sheets 21.

The cut surface F1 of the continuous fiber of the main UD sheet 20 is located on the longitudinal end surface of the main UD sheet 20, and the cut surface F2 of the continuous fiber of the sub UD sheet 21 is located on the widthwise side surface of the sub UD sheet 21. (See Fig. 5).

Inside each of the UD sheets 20 and 21, a plurality of continuous fibers may be bundled by auxiliary fibers. In this case, the mass ratio of the auxiliary fiber to the continuous fiber in the FRP structure is less than 20% as an example.

As shown in FIG. 4, the upper layer 15 and the lower layer 16 have at least one (plurality in this embodiment) main UD sheet laminate 22. The main UD sheet laminated body 22 is configured by laminating a predetermined number of main UD sheets 20 out of a plurality of main UD sheets 20 in the vertical direction. The predetermined number referred to here is set to a value in the range of several to several tens of sheets as an example, but is not limited to this.

In the leaf spring 10, the sub UD sheet 21 is laminated on the main UD sheet laminated body 22 in the plate thickness direction of the leaf spring 10. At least a pair of sub UD sheets 21 among the plurality of sub UD sheets 21 are arranged so as to sandwich the main UD sheet laminate 22 in the plate thickness direction of the leaf spring 10. In the upper layer 15 and the lower layer 16 of the present embodiment, the plurality of main UD sheet laminates 22 and the plurality of sub UD sheets 21 are alternately arranged in the plate thickness direction of the leaf spring 10.

The number of the main UD sheet laminates 22 included in the upper layer 15 and the lower layer 16 can be appropriately set, but can be set to a value in the range of several or more and several tens or less, for example. In the present embodiment, the upper layer 15 includes a dozen or more main UD sheet laminates 22, and the lower layer 16 includes several main UD sheet laminates 22. That is, the number of main UD sheet laminates 22 included in the upper layer is larger than the number of main UD sheet laminates 22 included in the lower layer 16.

In the leaf spring 10, the pair of sub UD sheets 21 may not be arranged so as to sandwich the main UD sheet laminate 22 in the plate thickness direction of the leaf spring 10. For example, even if at least one sub UD sheet 21 is laminated on the side opposite to the core layer 17 side of the main UD sheet laminated body 22 located farthest from the core layer 17 in the plate thickness direction of the leaf spring 10. good. Further, a plurality of sub UD sheets 21 may be continuously laminated on the main UD sheet laminated body 22 in the plate thickness direction of the leaf spring 10.

In each of the upper layer 15 and the lower layer 16, the total thickness direction dimension of the portion where the plurality of main UD sheets 20 are arranged is the total thickness direction dimension of the portion where at least one sub UD sheet 21 is arranged in the upper layer 15 and the lower layer 16. Is set larger than.

The plurality of sub-UD sheets 21 of the present embodiment include a first sub-UD sheet 21a and a second sub-UD sheet 21b. The first sub-UD sheet 21a has continuous fibers having a single orientation direction in which the first sub-UD sheet 21a is inclined at an angle in the range of 5 ° or more and 10 ° or less on one side in the width direction of the leaf spring 10 with respect to the longitudinal direction of the leaf spring 10. Oriented. The second secondary UD sheet 21b has continuous fibers having a single orientation direction in which the second sub-UD sheet 21b is inclined toward the other side in the width direction of the leaf spring 10 at an angle in the range of 5 ° or more and 10 ° or less with respect to the longitudinal direction of the leaf spring 10. Oriented.

In other words, the continuous fibers of the first secondary UD sheet 21a are counterclockwise from one end side to the other end side in the longitudinal direction of the leaf spring 10 when viewed from the normal direction of the first secondary UD sheet 21a. It is oriented in a direction of inclination at an angle in the range of 5 ° or more and 10 ° or less with respect to the longitudinal direction of 10.

Further, the continuous fibers of the second secondary UD sheet 21b are the longitudinal lengths of the leaf spring 10 clockwise from one end side to the other end side in the longitudinal direction of the leaf spring 10 when viewed from the normal direction of the second secondary UD sheet 21b. It is oriented in a direction of inclination at an angle in the range of 5 ° or more and 10 ° or less with respect to the direction. In the present embodiment, the plurality of sub-UD sheets 21 include the same number of the first sub-UD sheet 21a and the second sub-UD sheet 21b.

Each of the upper layer 15 and the lower layer 16 has a main UD layer 26, a sub UD layer 27, and a blocking layer 28. The main UD layer 26 is a main layer constituting the upper layer 15 and the lower layer 16. The main UD layer 26 is an FRP layer in which continuous fibers are oriented with the longitudinal direction of the leaf spring 10 as a single orientation direction. In the present embodiment, the main UD sheet laminate 22 is arranged and configured in the resin. There is.

The sub UD layer 27 is a layer laminated on the main UD layer 26 in the plate thickness direction of the leaf spring 10. The secondary UD layer 27 is an FRP layer in which continuous fibers are oriented with a single orientation direction in which the secondary UD layer 27 is inclined at an angle in the range of 5 ° or more and 10 ° or less in the width direction of the leaf spring 10 with respect to the longitudinal direction of the leaf spring 10. In the present embodiment, the sub UD sheet 21 is arranged in the resin.

The upper layer 15 and the lower layer 16 have a total portion of the plurality of main UD layers 26 as a main structure and a total portion of the plurality of sub UD layers 27 as a substructure. As a result, the leaf spring 10 has strength against a load in the vertical direction as a basic performance and also has high strength against a torsional load.

When a crack occurs in the core layer 17 in the plate thickness direction of the leaf spring 10, the blocking layer 28 blocks the crack from extending to the upper layer 15 or the lower layer 16. The blocking layer 28 is laminated on the main UD layer 26 on the core layer 17 side of the main UD layer 26 in the plate thickness direction of the leaf spring 10.

The blocking layer 28 is an FRP layer and includes a first continuous fiber and a second continuous fiber. In the barrier layer 28, the first continuous fiber is oriented in a direction in which the leaf spring 10 is inclined at an angle in the range of 40 ° or more and 50 ° or less on one side in the width direction of the leaf spring 10 with respect to the longitudinal direction of the leaf spring 10, and the leaf spring 10 is oriented. The second continuous fiber is oriented in a direction in which the leaf spring 10 is inclined at an angle in the range of 40 ° or more and 50 ° or less on the other side in the width direction with respect to the longitudinal direction of the leaf spring 10. The first continuous fiber and the second continuous fiber function as reinforcing fibers.

In other words, the first continuous fiber is in the range of 40 ° or more and 50 ° or less counterclockwise from one end side to the other end side in the longitudinal direction of the leaf spring 10 when viewed from the normal direction of the barrier layer 28. It is oriented in a direction that inclines at one angle. The first angle is 45 ° as an example.

Further, the second continuous fiber is formed at a second angle in the range of 40 ° or more and 50 ° or less clockwise from one end side to the other end side in the longitudinal direction of the leaf spring 10 when viewed from the normal direction of the barrier layer 28. It is oriented in the direction of inclination. The second angle is 45 ° as an example.

Since the first continuous fiber and the second continuous fiber of the blocking layer 28 are oriented in the direction of inclining at such an angle, a sufficient range of 40 ° or more and 50 ° or less with respect to the continuous fiber of the main UD layer 26 is sufficient. It intersects at various angles.

The blocking layer 28 of the present embodiment has a woven structure composed of first continuous fibers and second continuous fibers. The blocking layer 28 of the present embodiment is configured by arranging at least one (here, two) woven fiber sheets 23 having the woven structure in the resin. The woven fabric referred to here has a known woven fabric structure such as a plain woven fabric, a twill woven fabric, or a red woven fabric.

The blocking layer 28 does not have to have the woven fiber sheet 23. In this case, the blocking layer 28 may have a first blocking UD sheet containing the first continuous fiber and a second blocking UD sheet containing the second continuous fiber.

That is, in the blocking layer 28, the first continuous fiber is counterclockwise with respect to the longitudinal direction of the leaf spring 10 from one end side to the other end side in the longitudinal direction of the leaf spring 10 when viewed from the normal direction of the blocking layer 28. The first blocking UD sheet, which is oriented with the direction inclined at the first angle as a single orientation direction, and the leaf spring 10 from one end side to the other end side in the longitudinal direction when viewed from the normal direction of the blocking layer 28. Further, it may have a second blocking UD sheet in which the second continuous fiber is oriented clockwise at a second angle with respect to the longitudinal direction of the leaf spring 10 as a single orientation direction.

Here, the first angle and the second angle may be the same or different from each other. When the first angle and the second angle are the same, the first angle and the second angle may be, for example, 40 °, 45 °, or 50 °. When the first angle and the second angle are different from each other, for example, the first angle is either 40 °, 45 °, or 50 °, and the second angle is 40 °, 45 °, or 50. The angle of ° may be different from the first angle.

Further, the blocking layer 28 of the present embodiment is arranged at a portion of the upper layer 15 and the lower layer 16 closest to the core layer 17. The blocking layer 28 may be provided by at least one of the upper layer 15 and the lower layer 16.

At the time of manufacturing the upper layer 15 and the lower layer 16, a plurality of prepregs (FRP sheets) are laminated in the plate thickness direction of the leaf spring 10, and each time a predetermined number of prepregs are laminated, the prepreg laminated body 150 (see FIG. 6) is laminated. Pressurize and heat under reduced pressure. As an example, FIG. 5 is a diagram showing a state of the upper layer 15 of FIG. 2 at the time of manufacturing. As shown in FIG. 5, the upper layer 15 is composed of a plurality of prepregs laminated in the plate thickness direction of the leaf spring 10. The plurality of prepregs includes a plurality of main prepregs 30, at least one (plurality in this embodiment) sub-prepregs 31, and at least one blocking prepreg 32.

The main prepreg 30 is configured by impregnating the main UD sheet 20 with a resin. The sub-prepreg 31 is configured by impregnating the sub-UD sheet 21 with a resin. The sub-prepreg 31 has a first sub-prepreg 31a including a first sub-UD sheet 21a and a second sub-prepreg 31b including a second sub-UD sheet 21b. The blocking prepreg 32 is configured by impregnating the woven fiber sheet 23 with a resin. The resin impregnated in the sheets 20, 21, and 23 is an epoxy resin, but may be another resin, for example, a thermosetting resin such as polyimide, phenol, bismaleimide, polyimide, or vinyl ester. good.

The pair of first sub-prepregs 31a and second sub-prepregs 31b are arranged by sandwiching a main prepreg laminate in which a predetermined number of main prepregs 30 are laminated in the plate thickness direction of the leaf spring 10 in the plate thickness direction of the leaf spring 10. There is. In the present embodiment, the first sub-prepreg 31a and the second sub-prepreg 31b are alternately arranged with the main prepreg laminates sandwiched in the plate thickness direction of the leaf spring 10. At least one of the first sub-prepreg 31a and the second sub-prepreg 31b may be continuously arranged in the plate thickness direction of the leaf spring 10.

At the time of manufacturing the upper layer 15 and the lower layer 16, the main prepreg 30 and the sub prepreg 31 are laminated on the blocking prepreg 32 in a state where the blocking prepreg 32 is arranged on the most core layer 17 side of the upper layer 15 and the lower layer 16. The plurality of prepregs 30 to 32 are integrated by being pressurized and heated under reduced pressure.

The lower layer 16 is manufactured by the same method as the upper layer 15, but the number of the main prepreg 30 and the sub prepreg 31 is smaller than that of the upper layer 15. Further, as a method of pressurizing and heating a plurality of prepregs under reduced pressure, for example, a vacuum back method can be exemplified, but the method is not limited to this, and for example, an autoclave method may be used.

FIG. 6 is a perspective view showing a prepreg laminate 150 that is pressurized and heated under reduced pressure. Generally, in a prepreg laminate, some air may be mixed between adjacent prepregs. At least a part of this air is discharged along the orientation direction of the continuous fibers when each prepreg is pressurized and heated under reduced pressure. Here, the air mixed in both ends in the longitudinal direction of the prepreg laminate is easily discharged because the discharge path is relatively short, but the air mixed in the center in the longitudinal direction of the prepreg laminate has a relatively long discharge path. Therefore, it is difficult to be discharged.

As shown in FIG. 6, on the other hand, in the present embodiment, the cut surface F1 of the continuous fiber of the main UD sheet 20 is located at the end face in the longitudinal direction of the main UD sheet 20, and the cut surface of the continuous fiber of the sub UD sheet 21 is located. F2 is located on the side surface in the width direction of the sub UD sheet 21. Therefore, the fiber cross sections of the UD sheets 20 and 21 are arranged on both end faces in the longitudinal direction and both end faces in the width direction of the prepreg laminate 150.

As a result, the air mixed in the center of the prepreg laminated body 150 in the longitudinal direction moves along the discharge path along the orientation direction of the continuous fibers of the secondary UD sheet 21, and is easily discharged from the side surface in the width direction of the secondary UD sheet 21. .. The air discharged from the prepreg laminated body 150 includes not only the air mixed between the adjacent prepregs but also the air mixed in each prepreg.

In this way, when the prepreg laminate 150 is pressurized and heated under reduced pressure, air is efficiently discharged from the inside of the prepreg laminate 150 along the orientation direction of the continuous fibers of the UD sheets 20 and 21. Therefore, in the FRP structure of the leaf spring 10, it is possible to suppress the occurrence of internal defects due to the mixing of air, suppress the decrease in the yield at the time of manufacturing the leaf spring 10, and suppress the increase in the production cost.

Further, by arranging the plurality of main UD sheets 20 and the plurality of sub UD sheets 21 in the prepreg laminated body 150, it is possible to provide air discharge paths along a plurality of different directions, and the prepreg laminated body 150 can be provided with air discharge paths. The effect of discharging air from the inside can be further enhanced.

In the prepreg laminate 150, in order to obtain a good effect of discharging air from the inside of the prepreg laminate 150 by the UD sheets 20 and 21 as described above, at least one of the sheets 20 and 21 is included in the prepreg laminate 150. It is desirable to pressurize and heat the prepreg laminate 150 under reduced pressure while being contained one by one. As described above, the upper layer 15 and the lower layer 16 are manufactured by laminating a preset number of prepregs 30 to 32 and pressurizing and heating them under reduced pressure.

In the present embodiment, an example in which the upper layer 15 and the lower layer 16 are manufactured by using a plurality of prepregs 30 to 32 is shown, but the manufacturing method of the upper layer 15 and the lower layer 16 is not limited to this. Other manufacturing methods for the upper layer 15 and the lower layer 16 include, for example, a resin injection molding method (RIM) such as a resin transfer molding method (RTM) and a vacuum assisted resin transfer molding method (VARTM). Further, the manufacturing methods of the upper layer 15 and the lower layer 16 may be different from each other.

Here, in the case of manufacturing a leaf spring having an FRP structure, in order to efficiently obtain the strength against a load in the vertical direction in the leaf spring, only continuous fibers having the longitudinal direction of the leaf spring as a single orientation direction are reinforced fibers. However, when a torsional load is applied to the leaf spring, damage such as cracks may occur in the leaf spring.

As a countermeasure, in order to improve the strength of the leaf spring against the torsional load, it is conceivable to manufacture an FRP structure containing continuous fibers oriented in multiple directions as reinforcing fibers. In this case, the load in the vertical direction of the leaf spring is considered. It becomes difficult to design the leaf spring efficiently, and the weight of the leaf spring may increase and the production cost may increase.

On the other hand, according to the leaf spring 10 of the present embodiment, a predetermined number of long main UD sheets 20 in which continuous fibers are oriented with the longitudinal direction of the leaf spring 10 as a single orientation direction are laminated in the vertical direction. Due to the main UD sheet laminate 22, excellent strength against a load in the vertical direction can be obtained as a basic performance.

Further, the secondary UD sheet 21 in which the continuous fibers are oriented with the direction of inclination in the width direction of the leaf spring 10 at an angle in the range of 5 ° or more and 10 ° or less as a single orientation direction is provided with respect to the main UD sheet laminate 22. By laminating the leaf springs 10 in the plate thickness direction, high strength can be obtained even with respect to a torsional load. Specifically, the secondary UD sheet 21 reinforces the strength of the leaf spring 10 in the width direction, and suppresses the generation and expansion of cracks in the leaf spring 10 in the width direction.

Further, in each of the upper layer 15 and the lower layer 16, the total thickness direction dimension of the portion where the plurality of main UD sheets 20 are arranged is the total thickness of the portion where at least one sub UD sheet 21 is arranged in the upper layer 15 and the lower layer 16. Since it is larger than the directional dimension, it is possible to easily secure the strength against the torsional load while ensuring the high strength against the load in the vertical direction as the basic performance of the leaf spring 10.

Further, since at least a pair of sub UD sheets 21 among the plurality of sub UD sheets 21 sandwich the main UD sheet laminate 22 in the plate thickness direction, the main UD sheet 20 and the sub UD sheet 21 are combined with each other in the leaf spring 10. By adjusting the stacking order in the vertical direction, it is possible to easily adjust the balance of strength with respect to the load in the vertical direction and the torsional load.

Further, since the plurality of sub UD sheets 21 include both the first sub UD sheet 21a and the second sub UD sheet 21b in the same number, the leaf spring 10 is twisted in the circumferential direction perpendicular to the longitudinal direction of the leaf spring 10. Can be easily prevented.

Further, the cut surface F1 of the continuous fiber of the main UD sheet 20 is located on the longitudinal end surface of the main UD sheet 20, and the cut surface F2 of the continuous fiber of the sub UD sheet 21 is located on the side surface in the width direction of the sub UD sheet 21. Therefore, when the leaf spring 10 is manufactured, air can be efficiently discharged from the inside of the laminated structure of each of the UD sheets 20 and 21 along the orientation direction of the continuous fibers, and the air remains to cause an internal defect in the FRP structure. It can be reduced.

Further, at least one FRP structure in the leaf spring 10 includes at least one of the upper layer 15 laminated on one side of the core layer 17 in the plate thickness direction and the lower layer 16 laminated on the other side of the core layer 17 in the plate thickness direction. Therefore, in the leaf spring 10 including the upper layer 15, the lower layer 16, and the core layer 17, it is possible to obtain a high strength against a torsional load while having a high strength against a load in the vertical direction as a basic performance.

Further, in the core layer 17 of the present embodiment, among the plurality of layers 24, cracks such as delamination occur in the vertical direction (leaf spring 10) in the layer 24 and in the adhesive layer 19 between the adjacent layers 24. It is conceivable that it may occur so as to extend in the plate thickness direction of. Further, for example, even in the core layer 17 which does not have the adhesive layer 19, such as the core layer 17 which is integrally formed by laminating a plurality of layers 24 and pressurizing and heating, cracks are vertically generated from the inside of the layer 24. It may occur so as to extend in the direction.

Here, according to the leaf spring 10 of the present embodiment, in the upper layer 15 and the lower layer 16, the continuous fibers of the main UD layer 26 and the first continuous fibers and the second continuous fibers of the blocking layer 28 are 40 ° or more 50. Can be crossed at a sufficient angle in the range below °.

Therefore, when cracks occur in the core layer 17 in the vertical direction, the cracks propagate in the vertical direction through the gaps between the continuous fibers of the main UD layer 26 mainly on the core layer 17 side of the main UD layer 26. The blocking layer 28 laminated on the UD layer 26 in the plate thickness direction of the leaf spring 10 can block the UD layer 26 in advance. Therefore, it is prevented that the crack generated in the core layer 17 extends to the upper layer 15 or the lower layer 16 to deteriorate the performance of the leaf spring 10 and shorten the life of the leaf spring 10.

Further, regardless of the structure of the core layer 17, cracks may occur in the vertical direction between the core layer 17 and the blocking layer 28. In this case as well, the blocking layer 28 prevents cracks generated between the core layer 17 and the blocking layer 28 from extending to the upper layer 15 or the lower layer 16.

At least one of the upper layer 15 and the lower layer 16 has the main UD sheet laminate 22 as the first main UD sheet laminate, and a plurality of second main UD sheets different from the first main UD sheet laminate. It may have a laminated body. The second main UD sheet laminate is formed by laminating a plurality of main UD sheets 20 in the plate thickness direction of the leaf spring 10. The number of main UD sheets 20 included in each second main UD sheet laminate is different.

In the plate thickness direction of the leaf spring 10, each second main UD sheet laminate is arranged so as to sandwich at least one sub UD sheet 21. When a plurality of second main UD sheet laminates are arranged on the leaf spring 10, for example, as the plurality of second main UD sheet laminates are moved away from the core layer 17 in the plate thickness direction of the leaf spring 10, the second main UD It can be arranged so that the number of main UD sheets 20 included in the sheet laminate is reduced.

By using such a plurality of second main UD sheet laminates in combination with respect to the first main UD sheet laminate (main UD sheet laminate 22) and the sub UD sheet 21, the load and twist in the vertical direction can be obtained. The strength balance of the leaf spring 10 with respect to the load can be finely adjusted.

The present invention is not limited to the above-described embodiment, and its configuration can be changed, added, or deleted without departing from the spirit of the present invention.

1 Railcar bogie 4 Cross beam 5 Axle 7 Bearing 8 Axle box 10 Leaf spring 10c Leaf spring vehicle longitudinal end 15 Upper layer 16 Lower layer 17 Core layer 20 Main UD sheet 21 Sub UD sheet 21a 1st sub UD sheet 21b 2nd sub UD sheet 22 Main UD sheet laminate 26 Main UD layer (UD layer)
28 Blocking layer 50 Body

Claims (13)

A leaf spring for a railroad vehicle bogie having at least one long FRP structure.
The FRP structure is
A plurality of main UD sheets in which continuous fibers are oriented with the longitudinal direction of the leaf spring as a single orientation direction, and
It has at least one sub-UD sheet in which continuous fibers are oriented with a direction in which the leaf spring is inclined at an angle of 5 ° or more and 10 ° or less with respect to the longitudinal direction as a single orientation direction. ,
A railroad vehicle in which a predetermined number of main UD sheets are laminated in the vertical direction among the plurality of main UD sheets, and the sub UD sheets are laminated in the thickness direction of the leaf spring. Leaf spring for bogie. The first aspect of the FRP structure, wherein the total thickness dimension of the portion where the plurality of main UD sheets are arranged is larger than the total thickness dimension of the portion where the at least one sub UD sheet is arranged in the FRP structure. Leaf springs for railroad vehicle bogies. The at least one sub-UD sheet includes a plurality of the sub-UD sheets.
The leaf spring for a railcar bogie according to claim 1 or 2, wherein at least one pair of sub-UD sheets among the plurality of sub-UD sheets sandwiches the main UD sheet laminate in the plate thickness direction. The plurality of sub-UD sheets are the first sub-UD in which continuous fibers are oriented with a single orientation direction in which the plurality of sub-UD sheets are inclined at an angle in the range of 5 ° or more and 10 ° or less on one side in the width direction with respect to the longitudinal direction. Both the sheet and the second secondary UD sheet in which the continuous fibers are oriented with a single orientation direction in which the sheet is inclined at an angle in the range of 5 ° or more and 10 ° or less on the other side in the width direction with respect to the longitudinal direction. The leaf spring for a railroad vehicle bogie according to claim 3, which includes the same number of springs. The cut surface of the continuous fiber of the main UD sheet is located on the longitudinal end surface of the main UD sheet, and the cut surface of the continuous fiber of the sub UD sheet is located on the widthwise side surface of the sub UD sheet. The leaf spring for a railroad vehicle bogie according to any one of claims 1 to 4. With more core layer
The at least one FRP structure is at least one of an upper layer laminated on one side of the core layer in the plate thickness direction and a lower layer laminated on the other side of the core layer in the plate thickness direction. The leaf spring for a railcar bogie according to any one of 1 to 5. At least one of the upper layer and the lower layer has a blocking layer arranged in a portion closest to the core layer.
The railroad vehicle bogie according to claim 6, wherein the blocking layer contains continuous fibers oriented in a direction of inclining at an angle in the range of 40 ° or more and 50 ° or less in the width direction of the leaf spring with respect to the longitudinal direction. Leaf spring. A leaf spring for a railroad vehicle bogie equipped with a pair of long FRP structures.
With the core layer
The upper layer of the core layer, which is laminated on one side of the leaf spring in the plate thickness direction and is one of the pair of FRP structures,
A lower layer, which is laminated on the other side of the core layer in the plate thickness direction and is the other of the pair of FRP structures, is provided.
The upper layer and the lower layer are a UD layer in which continuous fibers are oriented with the longitudinal direction of the leaf spring as a single orientation direction, and the thickness of the leaf spring on the UD layer on the core layer side of the UD layer. It has a barrier layer laminated in the direction,
In the blocking layer, the first continuous fiber is oriented in a direction in which the leaf spring is inclined at an angle in the range of 40 ° or more and 50 ° or less on one side in the width direction of the leaf spring with respect to the longitudinal direction, and is oriented with respect to the longitudinal direction. A leaf spring for a railroad vehicle bogie, in which the second continuous fiber is oriented in a direction in which the second continuous fiber is inclined in a direction of inclining at an angle in the range of 40 ° or more and 50 ° or less on the other side in the width direction of the leaf spring. The leaf spring for a railroad vehicle bogie according to claim 8, wherein the core layer has a laminated structure in which a plurality of layers extending in the longitudinal direction are laminated in the width direction. The leaf spring for a railroad vehicle bogie according to claim 8 or 9, wherein the blocking layer has a woven structure composed of the first continuous fiber and the second continuous fiber. The leaf spring for a railcar bogie according to any one of claims 8 to 10, wherein the blocking layer is arranged at a portion of at least one of the upper layer and the lower layer closest to the core layer. A cross beam that extends in the width direction and supports the body of the railway vehicle,
A pair of axle boxes each containing bearings rotatably supporting the axles arranged on both sides of the cross beam in the longitudinal direction of the vehicle, and
The leaf spring for a railroad vehicle bogie according to any one of claims 1 to 11 is provided.
The railroad vehicle bogie is arranged so as to extend in the vehicle longitudinal direction, and the cross beams are supported in a state where both ends in the vehicle longitudinal direction are supported by the pair of axle boxes. .. The railroad vehicle bogie according to claim 12, wherein both ends of the leaf spring for the railroad vehicle bogie are supported without being fixed to the pair of axle boxes.

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