PROPULSION DEVICE SUPPORT MECHANISM

Description

This application is based upon and claims the benefit of priority to Japanese Patent Application No. 2024-107883, filed on Jul. 4, 2024, the entire content of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a propulsion device support mechanism whose posture is changed by forward and backward movement of a rod.

BACKGROUND ART

A hull and a propulsion device of the hull are coupled by a support member that supports the propulsion device. When the support member swings relative to the hull by forward and backward movement of a rod, a posture of the propulsion device is changed. A related technique regarding such a propulsion device support mechanism is disclosed in JP2020-124996A

A propulsion device support mechanism disclosed in JP2020-124996A includes a support member that is attached to a hull to be swingable about a swing shaft and supports a propulsion device. The support member includes a receiving portion that receives a top end portion of a rod.

SUMMARY OF INVENTION

The receiving portion that receives the rod is worn when the rod repeatedly moves forward and backward, and thus there is room for improvement.

Aspects of the present disclosure relates to providing a propulsion device support mechanism including a highly durable support member.

According to an aspect of the present disclosure, there is provided a A propulsion device support mechanism including:

• • a support member configured to support a propulsion device of a hull such that the propulsion device is swingable relative to the hull by forward and backward movement of a rod, in which
  • the support member includes a receiving portion that receives a top end portion of the rod,
  • the receiving portion has a convex surface protruding toward the top end portion of the rod, and
  • the convex surface has a uniform shape regardless of a position in a direction along a shaft of the support member such that the top end portion of the rod and the convex surface are in line contact.

According to another aspect of the present disclosure, there is provided a propulsion device support mechanism including:

• • a support member configured to support a propulsion device of a hull such that the propulsion device is swingable relative to the hull by forward and backward movement of a rod, in which
  • the support member is provided with a swingable receiving member that receives a top end portion of the rod, and
  • the top end portion of the rod and the receiving member are in surface contact with each other.

According to aspect of the present disclosure, a propulsion device support mechanism including a highly durable support member may be provided.

BRIEF DESCRIPTION OF DRAWINGS

Exemplary embodiment(s) of the present invention will be described in detail based on the following figures, wherein:

FIG. 1A illustrates a configuration around a stern of a hull in a propulsion device support mechanism according to Embodiment 1;

FIG. 1B illustrates a propulsion device whose posture is changed by a trim mechanism;

FIG. 2 is an enlarged view of a portion surrounded by a line 2 in FIG. 1A;

FIG. 3 illustrates a method for fixing a receiving member to a support member;

FIG. 4 illustrates the support member that swings by forward and backward movement of a rod of a trim device;

FIG. 5 illustrates a shape of a convex surface of a receiving portion when viewed from a direction along a shaft of the support member;

FIG. 6 illustrates a shape of a convex surface of a receiving portion in a propulsion device support mechanism according to Embodiment 2; and

FIG. 7 illustrates a support member and a receiving member in a propulsion device support mechanism according to Embodiment 3.

DESCRIPTION OF EMBODIMENTS

Embodiments will be described with reference to the attached drawings. The embodiments described herein are not intended to particularly limit the present disclosure. Elements constituting the embodiments can be appropriately combined. In addition, the same reference numerals are given to members and portions having the same functions, and redundant description will be appropriately omitted or simplified.

Embodiment 1

(Propulsion Device 13, Support Member 20)

Reference is made to FIG. 1A. A propulsion device support mechanism 10 according to Embodiment 1 will be described. A hull 11 includes, on a rear side, a propeller 12 driven by an engine, and is provided with a propulsion device 13 that propels the hull 11. The propulsion device 13 is supported by a support member 20. The support member 20 is swingable about a shaft 29 provided on an upper end portion of a stern 11a of the hull 11.

(Hydraulic Cylinder Device 15)

The propulsion device 13 supported by the support member 20 can have a posture changed by a hydraulic cylinder device 15. The hydraulic cylinder device 15 can be adjusted by a trim device 16 that raises the propulsion device 13 from a water surface and a tilt device 30 that adjusts an angle of the propeller 12 located underwater. FIG. 1B illustrates the propulsion device 13 whose posture is changed by the tilt device 30.

(Rod 40)

Reference is made to FIG. 2. The tilt device 30 includes a cylinder 31 including therein a piston movable by hydraulic oil, a rod 40 fixed to the piston and movable forward and backward relative to the cylinder 31, and a rod guide 32 blocking an end portion of the cylinder 31 and capable of guiding the rod 40 to move forward and backward.

(Top End Member 42 (Top End Portion) of Rod 40)

A top end member 42 (top end portion of the rod 40) is screwed and fixed to an end portion 41 of the rod 40 on a forward-moving side. The top end member 42 has a planar rod flat surface portion 43 facing the forward-moving side. The rod 40 and the top end member 42 may be integrated.

(Receiving Member 50, Receiving Portion 51)

Reference is made to FIGS. 2 and 3. A receiving member 50, which receives the rod 40 moving forward from the cylinder 31, is fixed to the support member 20. The receiving member 50 is a single solid member. The receiving member 50 has a substantially D-shaped (semi columnar) cross section, and includes a receiving portion 51 with which the rod 40 comes into contact, and a fixing portion 61 that is integrated with the receiving portion 51 and fixes the receiving portion 51 to the support member 20. The receiving portion 51 may be integrated with the support member 20.

(Convex Surface 52)

The receiving portion 51 has a convex surface 52 protruding toward the rod flat surface portion 43. The convex surface 52 is a curved surface having a shape bulging toward the rod flat surface portion 43. The convex surface 52 is uniform regardless of a position in a direction (see arrow (1) in FIG. 3) along the shaft 29 (see FIGS. 1A and 1B) that is a swing center of the support member 20.

Reference is made to FIGS. 4 and 5. The convex surface 52 includes a backward-moving contact portion 53 that comes into line contact with the rod flat surface portion 43 when the rod 40 moves backward most, and a forward-moving contact portion 54 that comes into line contact with the rod flat surface portion 43 when the rod 40 moves forward most. As the rod 40 moves forward and backward, the convex surface 52 slides relative to the rod flat surface portion 43. A slide range A1 of the convex surface 52 is between the backward-moving contact portion 53 and the forward-moving contact portion 54.

Reference is made to FIG. 5. The convex surface 52 has a shape whose radius of curvature gradually changes. The convex surface 52 has a maximum radius of curvature R1 at a top end 52a thereof. The top end 52a (maximum curvature portion 52a having the maximum radius of curvature R1) is included in the slide range A1 of the convex surface 52 relative to the rod flat surface portion 43. The curved surface shape of the convex surface 52 is not limited to a shape having a changing radius of curvature and may be a shape having a constant radius of curvature as long as the curved surface shape is located inside a semicircle S having a width L of the convex surface 52 as a diameter.

(Base Portion 21 of Support Member 20)

Reference is made to FIGS. 2 and 3. The support member 20 has a base portion 21 that fixes the fixing portion 61. The base portion 21 is a plate-shaped portion having a prescribed thickness, and has a through hole 22 through which the fixing portion 61 can pass.

(Fixing of Receiving Member 50)

The fixing portion 61 is, for example, a columnar portion, and is formed with a male thread 61a on an outer peripheral surface thereof. The fixing portion 61 passing through the through hole 22 is fastened by a female screw member 62 having a female thread 62a that can be fastened to the male thread 61a. The base portion 21 may be provided with a recess, and the angular fixing portion 61 may be press-fitted into the recess.

(Receiving Portion Support Portion 24, Supported Portion 55)

The base portion 21 has a planar receiving portion support portion 24 that faces the rod 40 and supports the receiving portion 51. The receiving portion 51 includes a planar supported portion 55 that faces a side opposite to the convex surface 52 and is supported by the receiving portion support portion 24. The supported portion 55 has a rectangular outer shape. The supported portion 55 and the receiving portion support portion 24 are in surface contact with each other.

(Restriction of Rotation of Receiving Portion 51)

The receiving portion 51 has a first side surface 58 and a second side surface 59 located on two sides of the convex surface 52 and facing opposite directions. When the receiving member 50 is fixed to the support member 20, the first side surface 58 and the second side surface 59 face the direction along the shaft 29 of the support member 20 (see arrow (1)). The receiving portion support portion 24 of the support member 20 is provided with a stopper 26 that restricts rotation of the receiving member 50. The stopper 26 has a contact surface 27 that can be brought into surface contact with the first side surface 58 of the receiving member 50 when the receiving member 50 attempts to rotate relative to the support member 20.

Embodiment 2

Reference is made to FIG. 6. A propulsion device support mechanism 10A according to Embodiment 2 will be described. Compared with Embodiment 1, only a shape of a receiving portion 71 is different. Description of the other configurations will be omitted.

When a line passing through a center of a convex surface 72 of the receiving portion 71 in a width L direction is defined as a center line C, a top end 72a of the convex surface 72 and a maximum curvature portion 75, which is a portion having a largest radius of curvature R2, are located in positions deviated from the center line C (the center line C is located between the top end 72a of the convex surface 72 and the maximum curvature portion 75).

The convex surface 72 includes a backward-moving contact portion 73 that comes into line contact with the rod flat surface portion 43 when the rod 40 moves backward most, and a forward-moving contact portion 74 that comes into line contact with the rod flat surface portion 43 when the rod 40 moves forward most. A slide range A2 of the convex surface 72 is between the backward-moving contact portion 73 and the forward-moving contact portion 74. The maximum curvature portion 75 is included in the slide range A2. The top end 72a may be within the slide range A2.

Embodiment 3

Reference is made to FIG. 7. A propulsion device support mechanism 10B according to Embodiment 3 will be described. A support member 90 is provided with a receiving member 80 that receives the rod flat surface portion 43. The receiving member 80 is swingable about a shaft 92 provided on a base portion 91 of the support member 90. The receiving member 80 includes an arm portion 81 having a shaft hole 81a through which the shaft 92 passes, and a receiving portion 82 that is provided at an end portion of the arm portion 81 on a radially outer side and receives the rod flat surface portion 43.

The receiving portion 82 has a planar receiving portion flat surface portion 83. The rod flat surface portion 43 and the receiving portion flat surface portion 83 are in surface contact. The receiving portion 82 is swingable about the shaft 92. For this reason, when the rod 40 moves forward and backward, the receiving portion flat surface portion 83 slides relative to the rod flat surface portion 43 while maintaining the surface contact with the rod flat surface portion 43.

Effects of Embodiments

Reference is made to 2. 1 to 3. According to a first aspect, the propulsion device support mechanism 10 includes:

• • the support member 20 configured to support the propulsion device 13 of the hull 11 such that the propulsion device 13 is swingable relative to the hull 11 by forward and backward movement of the rod 40, wherein
  • the support member 20 includes the receiving portion 51 that receives the top end member 42 (top end portion) of the rod 40,
  • the receiving portion 51 has the convex surface 52 protruding toward the top end member 42 of the rod 40, and
  • the convex surface 52 has a uniform shape regardless of a position in a direction along the shaft 29 of the support member 20, and thereby the top end member 42 of the rod 40 and the convex surface 52 are in line contact.

Compared with a configuration in which a flat surface and a sphere are in point contact, wear of the receiving portion 51 can be reduced since a contact area increases in line contact. It is possible to provide the propulsion device support mechanism 10 including the highly durable support member 20.

According to a second aspect, in the propulsion device support mechanism 10 in the first aspect,

• • when viewed from the direction along the shaft 29 of the support member 20, the convex surface 52 is a curved surface having a shape bulging toward the top end member 42 of the rod 40, and the top end member 42 includes the flat rod flat surface portion 43. A combination of the convex surface 52 which is a curved surface and the rod flat surface portion 43 which is a flat surface implements line contact. Accordingly, contact surface pressure can be reduced, and load-bearing capacity of the receiving portion 51 is improved.

Reference is made to FIGS. 2 and 3. According to a third aspect, in the propulsion device support mechanism in the first or second aspect,

• • the receiving portion 51 is restricted from rotating relative to the support member 20.

It is possible to prevent a load from concentrating on a part of the receiving portion 51. When the convex surface 52 of the receiving portion 51 having a D-shaped (semi columnar shaped) cross section is inclined relative to the rod flat surface portion 43 having a D-shaped cross section and a flat shape, a load is concentrated on a part of the convex surface 52 of the receiving portion 51. By restricting the rotation, the contact between the convex surface 52 and the rod flat surface portion 43 can be stabilized. A configuration for restricting the rotation of the receiving portion 51 is not limited to the stopper 26. For example, the receiving portion support portion 24 and the supported portion 55 may be provided with uneven portions that are fitted to each other.

Reference is made to FIG. 5. According to a fourth aspect, in the propulsion device support mechanism 10 in any one of the first to third aspects, of the convex surface 52, the maximum curvature portion 52a, which is a portion having a largest radius of curvature R1, is included in a range A1 in which the convex surface 52 slides relative to the rod flat surface portion 43. That is, a portion of the convex surface 52 that is relatively close to a flat surface comes into contact with the rod flat surface portion 43.

By adopting the convex surface 52 having a changing radius of curvature, an input direction of a load to the rod 40 is controlled. Specifically, when the support member 20 of the propulsion device 13 swings, a deviation of a contact position between the rod 40 and the receiving portion 51 has a larger contact range around the top end portion relative to the swing angle in a case of a larger radius of curvature of the convex surface 52 (the convex surface 52 being close to a flat surface) than in a case of the semicircle S having the width L of the convex surface 52 as a diameter, and the convex surface 52 can be brought into contact with the rod 40 on a relatively central side of the rod flat surface portion 43. Accordingly, a load on the rod 40 in a curving direction can be reduced. The convex surface 72 of the receiving portion 71 according to Embodiment 2 illustrated in FIG. 6 has the same effect.

Reference is made to FIG. 3. According to a fifth aspect, in the propulsion device support mechanism 10 in any one of the first to fourth aspects, the propulsion device support mechanism 10 includes the fixing portion 61 that is integrated with the receiving portion 51 and fixes the receiving portion 51 to the support member 20, the fixing portion 61 is formed with the male thread 61a, and the receiving portion 51 is fixed to the support member 20 by the female screw member 62 having the female thread 62a configured to be fastened to the male thread 61a. By forming the male thread 61a on a part of the receiving member 50 including the receiving portion 51 and preparing the female screw member 62, the receiving portion 51 can be easily fixed to the support member 20.

Reference is made to FIGS. 2 and 3. According to a sixth aspect, in the propulsion device support mechanism 10 in any one of the first to fifth aspects, the support member 20 includes the receiving portion support portion 24 that faces the rod 40 and supports the receiving portion 51, the receiving portion 51 includes the supported portion 55 supported by the receiving portion support portion 24, and the supported portion 55 and the receiving portion support portion 24 are in surface contact with each other.

Since the support member 20 receives a force applied from the rod 40 as a surface, the receiving portion 51 and the support member 20 are highly durable.

According to a seventh aspect, in the propulsion device support mechanism 10 in any one of the first to sixth aspects, the propulsion device support mechanism 10 includes a solid single member (receiving member 50) in which the receiving portion 51 and the fixing portion 61 that fixes the receiving portion 51 to the support member 20 are integrated.

The receiving member 50 is highly durable.

Reference is made to FIGS. 1A, 1B and 7. According to an eighth aspect, the propulsion device support mechanism 10B includes

• • the support member 90 configured to support the propulsion device 13 of the hull 11 such that the propulsion device 13 is swingable relative to the hull 11 by forward and backward movement of the rod 40,
  • the support member 90 is provided with the swingable receiving member 80 that receives the top end member 42 (top end portion) of the rod 40, and
  • the top end member 42 of the rod 40 and the receiving member 80 are in surface contact with each other. Since both the top end member 42 of the rod 40 and the receiving member 80 have flat surfaces, it is possible to provide the propulsion device support mechanism 10B including the highly durable support member 90.