JP7017391B2 - Shaft spring and its manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a shaft spring which is suitably used for a vehicle, particularly a railroad vehicle.

For example, in a railroad vehicle, a shaft spring interposed between a bogie frame and an axle side member is used in order to alleviate an impact during vertical movement. As a specific configuration of the shaft spring, as shown in Patent Document 1, a plurality of rubber layers and one or more hard partition walls are formed between a shaft core (spindle) and an outer cylinder having the same shaft center. It is known that an elastic portion of a laminated rubber structure in which a (intermediate hard cylinder) is concentrically laminated with an axial center and alternately laminated in the inner and outer diameter directions is interposed.

As a method for manufacturing the above-mentioned shaft spring, as shown in FIGS. 3 and 4 of Patent Document 1, a spindle 1, an outer cylinder 2 and a hard partition wall 5 are set in a mold, the mold is closed, and then the mold is not in the mold. A method of injecting vulcanized rubber and vulcanizing and molding the rubber layer 4 is known.

Japanese Unexamined Patent Publication No. 2011-127627

By the way, the height from the bogie frame to the car body varies from vehicle to vehicle. Therefore, even if the required spring constants of the elastic portions are the same, shaft springs having different heights may be required. To change the height of the shaft spring, a method of changing the height of the shaft core can be considered. However, the method described in Patent Document 1 has a problem that a new mold is required to manufacture a shaft spring using shaft cores having different heights, and the manufacturing cost is high.

Therefore, an object of the present invention is to make it possible to manufacture a plurality of shaft springs having different heights by using one mold.

In order to solve the above problems, as one aspect of the present invention, a shaft core, an outer cylinder, and an elastic layer interposed between the shaft core and the outer cylinder are provided, and the shaft core includes a shaft portion and a shaft portion. A method for manufacturing a shaft spring having a lower shaft portion and a flange portion formed between the shaft portion and the lower shaft portion, wherein an annular groove into which the flange portion can be fitted is formed on an inner peripheral surface. The annular groove is formed at a plurality of different types of shaft cores having different heights of the shaft portion by using a nested spacer and a mold capable of accommodating the shaft core to which the spacer is mounted. By combining the spacers of the above and making the height from the spacer to the top of the shaft portion constant with the spacer attached to the shaft core, a plurality of shafts having different heights in one mold. It is characterized in that the spring can be formed.

A convex portion is formed on either the outer peripheral surface of the flange portion of the shaft core or the inner peripheral surface of the annular groove of the spacer, and a concave portion that can be engaged with the convex portion is formed on the other, and the convex portion and the concave portion are formed. The forming position of the shaft core differs depending on the type of the shaft core, and the spacer may be mounted on the shaft core only when the combination of the shaft core and the spacer is appropriate.

A concave portion may be formed on the outer peripheral surface of the flange portion of the shaft core, and a convex portion may be formed on the inner peripheral surface of the annular groove of the spacer. Further, as the concave portion, the entire peripheral groove may be formed on the outer peripheral surface of the flange portion of the shaft core, and the convex portion may be formed on the inner peripheral surface in the annular groove of the spacer. Further, the convex portion may be formed for each spacer piece constituting the spacer.

A shaft spring manufactured by using a shaft core having a groove formed on the outer peripheral surface of the flange portion as a recess is an elastic layer interposed between the shaft core, the outer cylinder, and the shaft core and the outer cylinder. The shaft core has a shaft portion, a shaft lower portion, and a flange portion formed between the shaft portion and the shaft lower portion, and the height of the shaft portion is different for each type of shaft core. The entire peripheral groove for identification may be formed at different positions on the outer peripheral surface of the flange portion.

According to the method for manufacturing a shaft spring according to one aspect of the present invention, a cylindrical nested spacer having an annular groove into which a flange portion of the shaft core can be fitted is formed on the inner peripheral surface, and the spacer is provided. Using a mold that can accommodate the mounted shaft core, a plurality of spacers having different forming positions of the annular grooves are combined with each of a plurality of types of shaft cores having different heights of the shaft portion, and the spacers are mounted on the shaft core. In this state, the height from the spacer to the top of the shaft portion is made constant, so that it is possible to form a plurality of shaft springs having different heights with one mold.

Sectional drawing which shows the shaft spring which concerns on this invention Front view of shaft cores with different heights in this embodiment Sectional drawing which shows the shaft spring molding die of this embodiment Partial cross-sectional view showing the state where the spacer is attached to the shaft core A plan view showing a state in which both the spacer and the nest for forming are divided. Sectional view of FIG. A partial cross-sectional view showing a state in which a spacer is attached to a shaft core having a height different from that of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, a shaft spring for a railroad vehicle will be described. FIG. 1 is a cross-sectional view showing a shaft spring according to the present invention, FIG. 2 is a front view in which shaft cores having different heights in the present embodiment are arranged, and FIG. 3 is a shaft spring molding of the present embodiment. FIG. 4 is a cross-sectional view showing a metal mold, and FIG. 4 is a partial cross-sectional view showing a state in which a spacer is attached to a shaft core.

As shown in FIG. 1, the shaft spring according to the present invention includes a shaft core 1, an outer cylinder 2, and an elastic layer 3 interposed between the shaft core 1 and the outer cylinder 2. The elastic layer 3 has a laminated rubber structure in which a rubber layer 4 and an intermediate hard cylinder 5 are alternately laminated. The intermediate hard cylinder 5 is made of metal and is formed in a conical cylinder shape. The shaft core 1, the rubber layer 4, the intermediate hard cylinder 5, and the outer cylinder 2 all have the same shaft center P. In the figure, the arrow X indicates a vertical direction, X1 indicates an upward direction, and X2 indicates a downward direction.

The shaft core 1 is made of metal and has a hollow cylindrical shape. The shaft core 1 includes a shaft portion 6 and a flange portion 8 formed between the shaft lower portion 7 and the shaft portion 6 and the shaft lower portion 7. An all-circumferential groove 9 is formed on the outer peripheral surface of the flange portion 8.

In the present embodiment, as the shaft core 1, a plurality of shaft cores having different heights of the shaft portion 6 are used. FIG. 2 is a front view showing two types of shaft cores 1A and 1B having different heights of the shaft portion 6 arranged side by side. As shown in the figure, the shaft cores 1A and 1B have the same shape as the shaft lower portion 7 and the flange portion 8 (however, the positions where the all-circumferential grooves 9 are formed are different), and the height of the shaft portion 6 above the flange portion 8 is high. Is different. More specifically, the shaft portion 6 is composed of a conical cylinder portion 10 and a straight cylinder portion 11 interposed between the conical cylinder portion 10 and the flange portion 8. For convenience, the common names in the figures are given the same reference numerals.

The conical cylinder portions 10 of the shaft cores 1A and 1B have the same shape, and the heights of the straight cylinder portions 11 are different. The rubber layer 4 is vulcanized and adhered to the conical cylinder portion 10. As a result, even if the heights of the shaft portions 6 of the shaft cores 1A and 1B are different, the shape of the elastic portion 3 is the same, the spring constant of the elastic portion 3 is constant, and only the height of the shaft portion 6 is different. Can be obtained.

Regarding a method of manufacturing a shaft spring with one molding die using shaft cores having different heights of the shaft portion 6, first, a case where a shaft core 1A having a high shaft portion 6 height is used will be described. FIG. 3 is a cross-sectional view of a shaft spring forming mold used in the present invention, showing a state in which a shaft spring is formed in the mold. The shaft spring forming mold includes a main mold 21, a bottom mold 22, and a lid mold 23. The main mold 21 has a substantially columnar appearance, and a space for accommodating a shaft spring is formed inside.

The lid type 23 includes an injection type 23a and an injection receiving type 23b. The injection type 23a is provided so as to be movable up and down in the injection receiving type 23b, raises the injection type 23a, and supplies unvulcanized rubber to the space formed between the injection type 23a and the injection receiving type 23b, and is an injection type. By lowering the 23a, unvulcanized rubber can be injected into the main mold 21 from a plurality of injection ports 24 provided at the bottom of the injection receiving mold 23b.

When molding a shaft spring using the molding die having the above configuration, as shown in FIG. 4, a cylinder having an annular groove 25 formed on the inner peripheral surface to fit the flange portion 8 of the shaft core 1A. The nested spacer 26 is mounted on the flange portion 8 of the shaft core 1A. The spacer 26 is composed of two semi-cylindrical spacer pieces 26a and 26a.

A convex portion 27 is formed on the inner peripheral surface of the annular groove 25 of the spacer 26. At least one convex portion 27 is formed on each spacer piece 26a. In the present embodiment, the convex portions 27 are formed one by one on the nuclear spacer piece 26a. The convex portion 27 is formed in the annular groove 25 at the left and right center positions of the spacer piece 26a at a height corresponding to the all-circumferential groove 9 formed on the outer peripheral surface of the flange portion 8. When the spacer 26 is mounted on the flange portion 8 of the shaft core, the convex portion 27 enters the all-circumferential groove 9, and the spacer 24 is properly mounted on the shaft core 1A.

By forming the convex portion 27 at the center position on the left and right of the spacer piece 26a, when the spacer piece 26a is attached to the flange portion 8, the combination of the spacer 26 and the shaft core 1A is improper, and the convex portion 27 is convex. Even when the portion 27 comes into contact with the outer peripheral surface of the flange portion 8, since it contacts in a direction orthogonal to the outer peripheral surface of the flange portion 8, damage to the convex portion 27 can be suppressed.

A spacer holding portion 28 into which the spacer 26 can be fitted is formed in the central portion of the main mold 21. Specifically, a concave shaft lower receiving portion into which the shaft lower portion 7 can be fitted is formed in the center of the bottom of the main mold 21, and the shaft lower portion is concentric with the shaft lower receiving portion via a step portion on the upper side thereof. A concave portion of the large diameter is formed from the receiving portion, and the spacer holding portion 28 is formed by the stepped portion and the concave portion. The shaft core 1A to which the spacer 26 is mounted is positioned by fitting the spacer 26 into the spacer holding portion 28 in the main mold 21. After that, a molding insert 29 for molding the lower end portion of the rubber layer 4 of the innermost layer of the elastic portion 3 is placed on the spacer 26. The molding insert 29 has a tubular shape and is composed of semi-cylindrical nesting pieces 29a and 29a.

FIG. 5 is a plan view showing a state in which the spacer 26 and the molding insert 29 are both divided, and FIG. 6 is a cross-sectional view thereof. As shown in the figure, the spacer 26 and the molding insert 29 are combined to form an inverted conical cylinder. The spacer holding portion 28 has a tapered surface corresponding to this inverted conical cylinder, and when the spacer 26 and the molding insert 29 are fitted into the spacer holding portion 28, the contact surface between the spacer pieces 26a and 26a and the contact surface between the spacer pieces 26a and 26a are formed. The contact surfaces of the molding inserts 29a and 29a are in close contact with each other, and the unvulcanized rubber does not enter between the contact surfaces.

After the molding insert 29 is set in the main mold 21, the intermediate hard cylinder 5 and the outer cylinder 2 are set in the main mold 21. After that, the injection receiving mold 23b is fitted to the main mold 21 and closed. The steps up to this point are performed with the mold heated. After confirming that the mold has a predetermined temperature, unvulcanized rubber is supplied to the space (injection pod) between the injection mold 23a and the injection receiving mold 23b in the raised state, and the injection mold 23a is lowered. Unvulcanized rubber is injected into the main mold 21 and vulcanized.

After the molding is completed, the lid mold 23 is raised to open the mold, and the shaft spring with the spacer 26 and the molding insert 29 attached is taken out. After opening the spacer 26 to the left and right and removing it from the flange portion 8, the molding insert 29 is pulled down and opened to the left and right to be removed from the shaft spring.

Next, a method of manufacturing a shaft spring using the molding die when the shaft core 1B having a low shaft portion 6 height is used will be described. As shown in FIG. 7, it is the same as in FIG. 4 in that a cylindrical nested spacer 26 having an annular groove 25 formed on the inner peripheral surface into which the flange portion 8 of the shaft core 1B can be fitted is used. .. For each part of the spacer 26, the same reference numerals are given to the names common to those in FIG. 4 for convenience.

In FIGS. 7 and 4, the outer shape of the spacer 26 is the same, but the position where the annular groove 25 is formed in the spacer 26 is different. That is, in the shaft core 1B, the height of the straight cylinder portion 11 is formed lower than the height of the straight cylinder portion 11 of the shaft core 1A, and the position of the annular groove 25 in the spacer 26 is set to the shaft core 1A by the amount of the lower height. It is formed at a position higher than the spacer 26 used. As a result, the height from the spacer 26 to the top of the shaft portion of the shaft core 1B becomes constant with the spacer 26 attached, and it is possible to form a plurality of shaft springs having different heights with one mold. Become.

In FIG. 7, a convex portion 27 is formed on the outer peripheral surface of the flange portion 8 of the shaft core 1B and on the inner peripheral surface of the annular groove 25 of the spacer 26 corresponding to the all-circumferential groove 9. Is the same as in FIG. However, the position of forming the all-circumferential groove 9 is different between the shaft core 1A and the shaft core 1B, and the position of the convex portion formed on the spacer 26 is also different accordingly.

Specifically, in the shaft core 1A, the all-around groove 9 is formed at a high position in the flange portion 8, and in the shaft core 1B, the all-around groove 9 is formed at a low position in the flange portion 8. That is, the formation positions of the all-circumferential grooves 9 in the flange portion 8 are different on the vertical direction X (the axial center P direction).

Therefore, when the shaft core 1B and the spacer 26 in FIG. 7 are combined, the spacer 26 can be mounted on the shaft core 1B, while the spacer 26 can be mounted on the flange portion 8 of the shaft core 1A (see FIG. 4). ) Is attached to the shaft core 1B, the convex portion of the spacer 26 comes into contact with the outer peripheral surface of the flange portion 8 of the shaft core 1B. It can be avoided. This makes it possible to prevent molding defects and damage to the mold caused by incorporating the shaft core 1 and the spacer 26 into the mold while the combination is improper.

The shaft spring of the present invention thus obtained includes a shaft core 1, an outer cylinder 2, and an elastic layer 3 interposed between the shaft core 1 and the outer cylinder 2, and the shaft core 1 is a shaft core 1. Flange for each type of shaft core 1A and 1B having a shaft portion 6, a shaft lower portion 7, and a flange portion 8 formed between the shaft portion 6 and the shaft portion 7 and having different heights of the shaft portion 6. All-around grooves 9 for identification are formed at different positions on the outer peripheral surface of the portion 8. In addition, in order to improve the distinctiveness, it is possible to apply different coloring to each of the circumferential grooves 9.

Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention. For example, in the present embodiment, in order to determine the suitability of the combination of the shaft core and the spacer, an all-circumferential groove is formed on the outer peripheral surface of the flange portion of the shaft core, but the present invention is not limited to this, and a convex portion is engaged. A compatible recess may be formed. In this case, the shaft core and the spacer may be marked for alignment. Further, a convex portion may be formed on the flange portion and a concave portion may be formed on the spacer.

The constituent elements disclosed in the present embodiment and the above-described modifications can be combined with each other, and by combining them, new technical features can be formed.

1 Shaft core 2 Outer cylinder 3 Elastic layer 4 Rubber layer 5 Intermediate hard cylinder 6 Shaft part 7 Shaft lower part 8 Flange part 9 All-around groove 10 Conical cylinder part 11 Straight cylinder part 21 Main type 22 Bottom type 23 Lid type 23a Injection type 23b Injection Receiving type 24 Injection port 25 Circular groove 26 Spacer 27 Convex part 28 Spacer holding part 29 Insertion for molding

Claims (6)

A shaft core, an outer cylinder, and an elastic layer interposed between the shaft core and the outer cylinder are provided, and the shaft core is formed between the shaft portion, the shaft lower portion, and the shaft portion and the shaft lower portion. A method for manufacturing a shaft spring having a flange portion, which is a method of manufacturing a shaft spring, in which a cylindrical nested spacer having an annular groove into which the flange portion can be fitted is formed on an inner peripheral surface, and a shaft on which the spacer is mounted. Using a mold capable of accommodating the core, a plurality of spacers having different positions of forming the annular groove are combined with each of a plurality of types of shaft cores having different heights of the shaft portion, and the spacers are mounted on the shaft core. By making the height from the spacer to the top of the shaft portion constant in this state, it is possible to form a plurality of shaft springs having different heights with one mold. Production method. A convex portion is formed on either the outer peripheral surface of the flange portion of the shaft core or the inner peripheral surface of the annular groove of the spacer, and a concave portion that can be engaged with the convex portion is formed on the other, and the convex portion and the concave portion are formed. The shaft according to claim 1, wherein the formation position of the shaft is different for each type of the shaft core, and the spacer can be mounted on the shaft core only when the combination of the shaft core and the spacer is appropriate. How to make a spring. The method for manufacturing a shaft spring according to claim 2, wherein a concave portion is formed on the outer peripheral surface of the flange portion of the shaft core, and a convex portion is formed on the inner peripheral surface of the annular groove of the spacer. 2 . The method for manufacturing a shaft spring according to the description. The method for manufacturing a shaft spring according to any one of claims 2 to 4, wherein the convex portion is formed for each spacer piece constituting the spacer. A shaft core, an outer cylinder, and an elastic layer interposed between the shaft core and the outer cylinder are provided, and the shaft core is formed between the shaft portion, the shaft lower portion, and the shaft portion and the shaft lower portion. A shaft spring having a flange portion is characterized in that an all-around groove for identification is formed at a different position on the outer peripheral surface of the flange portion for each type of shaft core having a different height of the shaft portion. Shaft spring.

Images