Patent Description:
Patent Document <NUM> discloses a union bolt. The union bolt of Patent Document <NUM> includes a head portion, and a shaft portion provided at a lower end of the head portion and provided with an external thread groove on an outer peripheral surface thereof. The shaft portion includes a vertical hole provided inside the shaft portion and through which the fluid flows in a direction substantially along an axial direction, and a lateral hole provided substantially orthogonal to the axial direction so that the vertical hole can communicate with an outside.

In the union bolt of Patent Document <NUM>, in order to increase tightening axial force, for example, it is conceivable to decrease an inner diameter of the vertical hole. However, when the inner diameter of the vertical hole is decreased, a dimension of a portion of the shaft portion where the lateral hole is formed increases, and it may be difficult to shape the lateral hole having a small diameter by press working.

An object of the present disclosure is to provide a banjo bolt in which a lateral hole having a small diameter can be formed by press working while a decrease in fastening axial force is suppressed.

A banjo bolt according to one aspect of the present disclosure includes.

According to the banjo bolt of the above aspect, it is possible to form a lateral hole having a small diameter by press working while a decrease in fastening axial force is suppressed.

Hereinafter, an example of the present disclosure will be described with reference to the accompanying drawings. Note that the following description is merely exemplary in nature, and is not intended to limit the present disclosure, its application, or its use. Furthermore, the drawings are schematic, and ratios of dimensions and the like do not necessarily match actual ones.

As shown in <FIG>, a banjo bolt (also referred to as union bolt) <NUM> according to one embodiment of the present disclosure includes a head portion <NUM> and a cylindrical shaft portion <NUM>. The banjo bolt <NUM> is made of, for example, carbon steel, alloy steel, boron steel, stainless steel, aluminum, or the like. The shaft portion <NUM> has, for example, a substantially cylindrical shape and extends along a first direction (for example, in the Z direction,).

As illustrated in <FIG>, the head portion <NUM> includes, for example, a screw head <NUM> having a substantially hexagonal columnar shape and a flange <NUM>, and is provided at one end of the shaft portion <NUM> in the first direction Z. The screw head <NUM> is located farther from the other end of the shaft portion <NUM> in the first direction Z than the flange <NUM>. The flange <NUM> has, for example, a substantially annular shape and is located around a center line CL extending in the first direction Z of the shaft portion <NUM>.

As illustrated in <FIG>, the shaft portion <NUM> has, for example, a substantially cylindrical shape, and internally includes a vertical hole <NUM> extending along the first direction Z. The vertical hole <NUM> has, for example, a substantially circular shape, extends from the head portion <NUM> to the other end of the shaft portion <NUM> in the first direction Z, and is connected to an opening <NUM> provided at the other end of the shaft portion <NUM> in the first direction Z. The vertical hole <NUM> is shaped in the shaft portion <NUM> by, for example, cold casting. The shape of the vertical hole <NUM> is not limited to a substantially circular shape, and may be any other shape.

As illustrated in <FIG>, the shaft portion <NUM> includes at least one groove portion <NUM> and a lateral hole <NUM> provided in a bottom portion <NUM> of the groove portion <NUM>. The groove portion <NUM> is provided on the inner surface of the vertical hole <NUM>, more specifically, on a peripheral wall portion <NUM> of the shaft portion <NUM> constituting the inner surface of the vertical hole <NUM>. In the present embodiment, as an example, the shaft portion <NUM> includes two groove portions <NUM> and two lateral holes <NUM> located symmetrically with respect to the center line CL extending in the first direction Z of the vertical hole <NUM>.

Each groove portion <NUM> extends along the first direction Z and is recessed in a second direction (for example, in the X direction) intersecting the first direction and in a direction away from the center line CL. As an example, each groove portion <NUM> includes a cross section intersecting the center line CL, the cross section being substantially uniform from one end to the other end in the first direction Z. In the present embodiment, one lateral hole <NUM> is provided in only one of the two groove portions <NUM>.

A portion constituting the bottom portion <NUM> of each groove portion <NUM> in the peripheral wall portion <NUM> of the shaft portion <NUM> is defined as a thin portion <NUM>, and a portion other than the thin portion <NUM> in the peripheral wall portion <NUM> of the shaft portion <NUM> is defined as a thick portion <NUM>. In the present embodiment, the ratio of a thickness of the thin portion <NUM> to a thickness of the thick portion <NUM> (for example, W3/W4) is preferably larger than zero and smaller than <NUM>. The thin portion <NUM> and the thick portion <NUM> are alternately positioned in the circumferential direction with respect to the center line CL. The thicknesses of the thin portion <NUM> and the thick portion <NUM> are dimensions of the peripheral wall portion <NUM> in a direction intersecting the first direction Z (in the present embodiment, in the radial direction with respect to the center line CL).

The lateral hole <NUM> extends through the peripheral wall portion <NUM> of the shaft portion <NUM> in the second direction to connect the vertical hole <NUM> and an outside of the shaft portion <NUM>. The lateral hole <NUM> has, for example, a substantially circular shape, and is provided at an arbitrary position of the bottom portion <NUM> of the groove portion <NUM>. The lateral hole <NUM> is formed in the shaft portion <NUM> by, for example, press working. The shape of the lateral hole <NUM> is not limited to a substantially circular shape, and may be any other shape.

When viewed along the first direction Z, a dimension in the circumferential direction with respect to the center line CL of the bottom portion <NUM> of the groove portion <NUM> is defined as W1, and a dimension in the circumferential direction with respect to the center line CL of the lateral hole <NUM> is defined as W2. In the present embodiment, a ratio (= W1/W2) of the lateral hole <NUM> to the bottom portion <NUM> of the groove portion <NUM> when viewed along the first direction Z is larger than zero and equal to or smaller than <NUM>.

As illustrated in <FIG>, the shaft portion <NUM> includes an external threaded portion <NUM> located at the other end in the first direction Z. The external threaded portion <NUM> is provided on an outer surface around the center line CL of the shaft portion <NUM>.

The banjo bolt <NUM> can exhibit the following advantageous effects.

The banjo bolt <NUM> includes the head portion <NUM> and the shaft portion <NUM> including the vertical hole <NUM> extending along the first direction Z. The head portion <NUM> is connected to one end of the shaft portion <NUM> in the first direction Z. The opening <NUM> connected to the vertical hole <NUM> is provided at the other end of the shaft portion <NUM> in the first direction Z. The shaft portion <NUM> includes at least one groove portion <NUM> and the lateral hole <NUM>. The at least one groove portion <NUM> is provided on the inner surface of the vertical hole <NUM>, extends in the first direction Z, and is recessed in the second direction intersecting the first direction Z and in a direction away from the center line CL extending in the first direction Z of the vertical hole <NUM>. The lateral hole <NUM> is provided in the bottom portion <NUM> of the groove portion <NUM> and extends in the second direction to connect the vertical hole <NUM> and the outside of the shaft portion <NUM>. With such a configuration, since only the portion where the lateral hole <NUM> is formed in the thickness of the peripheral wall portion <NUM> of the shaft portion <NUM> is thin, it is possible to realize the banjo bolt <NUM> in which a lateral hole having a small diameter can be formed by press working while a decrease in fastening axial force (in other words, surface pressure) is suppressed.

In general, when the lateral hole <NUM> is formed by press working, a piercing punch is used. For example, when the lateral hole <NUM> is formed in the thick portion <NUM> of the peripheral wall portion <NUM>, a processing load necessary for processing the lateral hole <NUM> increases as compared with the case where the lateral hole <NUM> is formed in the thin portion <NUM>. When the processing load exceeds material strength of the piercing punch, the piercing punch is broken (= exceeds processing limit), and thus the following disadvantages may occur. Since the banjo bolt <NUM> can be formed by press working, occurrence of such a disadvantage can be avoided.

The groove portion <NUM> includes a cross section intersecting the center line CL, the cross section being substantially uniform from one end to the other end in the first direction Z. With such a configuration, the banjo bolt <NUM> having uniform fastening axial force can be realized.

Assuming that a portion constituting the bottom portion <NUM> of the groove portion <NUM> of the shaft portion <NUM> is the thin portion <NUM> and a portion other than the thin portion <NUM> of the shaft portion <NUM> is the thick portion <NUM>, a ratio of a thickness of the thin portion <NUM> to a thickness of the thick portion <NUM> is larger than zero and smaller than <NUM>. With such a configuration, it is possible to more reliably realize the banjo bolt <NUM> in which a lateral hole having a small diameter can be formed by press working while a decrease in fastening axial force is suppressed.

A ratio of the lateral hole <NUM> to the bottom portion <NUM> of the groove portion <NUM> when viewed along the first direction Z is larger than zero and equal to or smaller than <NUM>. With such a configuration, it is possible to more reliably realize the banjo bolt <NUM> in which a lateral hole having a small diameter can be formed by press working while a decrease in fastening axial force is suppressed.

The shaft portion <NUM> has a plurality of groove portions <NUM>, and the plurality of groove portions <NUM> are located symmetrically with respect to the center line CL. With such a configuration, a plurality of lateral holes <NUM> can be formed in the shaft portion <NUM>.

The banjo bolt <NUM> may be configured as follows.

The shaft portion <NUM> only needs to include at least one groove portion <NUM>. For example, as illustrated in <FIG>, one groove portion <NUM> may be provided in the shaft portion <NUM>. As illustrated in <FIG>, two groove portions <NUM> may be provided in the shaft portion <NUM>. Although not illustrated, three or more grooves portions <NUM> may be provided in the shaft portion <NUM>.

The shaft portion <NUM> only needs to include at least one lateral hole <NUM>. For example, as illustrated in <FIG>, one lateral hole <NUM> may be provided in each of the plurality of groove portions <NUM>. Although not illustrated, a plurality of lateral holes <NUM> may be provided in one groove portion223.

The head portion <NUM> may adopt any shape and configuration. For example, the shape of the screw head <NUM> is not limited to a substantially hexagonal prism, and may be a hexalobular, twelve-point, triple square, or the like. As illustrated in <FIG>, the head portion <NUM> may have a configuration in which the flange <NUM> is omitted.

Various embodiments of the present disclosure have been described above in detail with reference to the drawings. Finally, various aspects of the present disclosure will be described.

A banjo bolt according to a first aspect of the present disclosure includes.

In a banjo bolt according to a second aspect of the present disclosure, the groove portion includes a cross section intersecting the center line, the cross section being substantially uniform from one end to the other end in the first direction.

According to a banjo bolt of a third aspect of the present disclosure, in the banjo bolt of the first aspect or the second aspect, assuming that a portion constituting a bottom portion of the groove portion of the shaft portion is a thin portion, and that a portion other than the thin portion of the shaft portion is a thick portion, a ratio of a thickness of the thin portion to a thickness of the thick portion is larger than zero and smaller than <NUM>.

According to the banjo bolt <NUM> of a fourth aspect of the present disclosure is, in the banjo bolt according to any one of the first to third aspects, a ratio of the lateral hole to the bottom portion of the groove portion when viewed along the first direction is larger than zero and equal to or smaller than <NUM>.

According to the banjo bolt <NUM> of a fifth aspect of the present disclosure, in the banjo bolt according to any one of the first to fourth aspects, the shaft portion includes a plurality of the groove portions, and the plurality of the groove portions are located symmetrically with respect to the center line.

By appropriately combining arbitrary embodiments or modifications among the various embodiments or modifications described above, it is possible to achieve the effects of the respective embodiments. In addition, combinations of embodiments, combinations of examples, or combinations of embodiments and examples are possible, and combinations of features in different embodiments or examples are also possible.

Claim 1:
A banjo bolt (<NUM>), comprising:
a head portion (<NUM>); and
a cylindrical shaft portion (<NUM>) including a vertical hole (<NUM>), the vertical hole extending in a first direction and being provided inside the shaft portion, wherein
the head portion is connected to a first end of the shaft portion in the first direction,
an opening (<NUM>) connected to the vertical hole is provided at a second end of the shaft portion in the first direction, and
the shaft portion includes
at least one groove portion (<NUM>) provided on an inner surface of the vertical hole, the groove portion extending along the first direction, and being recessed in a second direction intersecting the first direction and in a direction away from a center line of the vertical hole extending in the first direction, and
a lateral hole (<NUM>) provided in a bottom portion (<NUM>) of the groove portion, the lateral hole extending in the second direction and connecting the vertical hole and an outside of the shaft portion.