Tilt device for marine propulsion unit

A tilt device for a marine propulsion unit in which a cylinder device is interposed between a stern bracket fixed to a boat body and a swivel bracket which supports a propulsion unit, the cylinder device is divided into a first tilt chamber closer to a side in which a piston rod is accommodated and a second tilt chamber closer to a side in which the piston rod is not accommodated by means of a piston fixed to a piston rod, and the tilt device includes a shock blow valve which makes it possible to expand the piston rod by sending oil in the first tilt chamber to the second tilt chamber through a communication hole formed in the piston which is opened and closed with a constant set pressure, wherein

• the shock blow valve comprises a disk valve fixed to a valve seat surface of the piston, the valve seat surface is provided with a seal member surrounding a communication hole which opens at the valve seat surface, and the disk valve is tightly connected to the seal member;
• the piston includes a plurality of communication holes, the tilt device further comprises a single seal member which collectively surrounds all of the communication holes;
• a holding groove of the seal member is formed in the valve seat surface of the piston, and the seal member is adhered to the holding groove;
• the holding groove formed in the valve seat surface of the piston auxiliary includes a flowing groove for inject-forming the seal member.

A tilt device for a marine propulsion unit in which a cylinder device is interposed between a stern bracket fixed to a boat body and a swivel bracket which supports a propulsion unit, the cylinder device is divided into a first tilt chamber closer to a side in which a piston rod is accommodated and a second tilt chamber closer to a side in which the piston rod is not accommodated by means of a piston fixed to a piston rod, and the tilt device includes a shock blow valve which makes it possible to expand the piston rod by sending oil in the first tilt chamber to the second tilt chamber through a communication hole formed in the piston which is opened and closed with a constant set pressure, wherein

• the shock blow valve comprises a disk valve fixed to a valve seat surface of the piston, the valve seat surface is provided with a seal member surrounding a communication hole which opens at the valve seat surface, and the disk valve is tightly connected to the seal member,
• the piston includes a plurality of communication holes, the tilt device further comprises a plurality of seal members each of which surrounds each of the communication holes;
• a holding groove of the seal member is formed in the valve seat surface of the piston, and the seal member is adhered to the holding groove;
• the holding groove formed in the valve seat surface of the piston auxiliary includes a flowing groove for inject-forming the seal member.