JP2667670B2 - Cylinder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cylinder used as a member for positioning and supporting various devices. (Prior Art) As a cylinder for positioning and supporting various devices, there is, for example, a tilt damper of a boat outboard motor. In this system, an orifice and a relief valve are provided between the oil chamber on the rod extension side and the oil chamber on the compression side in the cylinder, and when the outboard motor collides with an obstacle or the like, it is reduced via the relief valve. The outboard motor floats from the water surface by releasing the oil on the side to the extension side and freeing the rod. When the outboard motor is set from the propulsion position or the propulsion position to the floating position when the outboard motor is pushed downward or upward, the oil in both oil chambers enters and exits through the orifices. It is easily set (see Japanese Patent Publication No. 59-5480). (Problems to be Solved by the Invention) However, in such a conventional example, the outboard motor can be set at the propulsion position and the floating position, but both oil chambers of the cylinder communicate with each other through the orifice. Therefore, it is not possible to set the outboard motor at a desired angle in accordance with the water depth or the like. Further, when the conventional example is applied to a device other than the outboard motor, it is impossible to apply the device to a device that is to be held at an arbitrary intermediate position. An object of the present invention is to solve such a problem. (Means for Solving the Problems) The present invention defines a rod extension-side oil chamber and a rod-reduction-side oil chamber by slidably housing a piston having a rod connected to a cylinder body, while providing hydraulic oil. A relief valve that has an accumulator that pressurizes the oil, opens the accumulator chamber of the accumulator to the rod compression oil chamber, and opens the accumulator chamber to the rod expansion oil chamber when the hydraulic oil pressure in the oil chamber is equal to or higher than a set value. And a lever for forcibly opening and closing the relief valve is provided. (Operation) When the relief valve is opened by the lever, the accumulator, the oil chamber on the rod contraction side, and the oil chamber on the rod extension side all communicate with each other, so that the rod moves to the extension side or the contraction side according to the external force applied. . At this time, the oil chamber of the accumulator acts on the rod extension side as an assist force according to the piston pressure receiving area difference. When the relief valve is closed by the lever after moving the rod to an arbitrary position, the oil chamber on the rod extension side is shut off from the pressure accumulation chamber and the oil chamber on the rod compression side by the relief valve, and the oil pressure in the pressure accumulation chamber is reduced. Since the rod acts on the oil chamber on the contraction side of the rod, the rod is locked at an arbitrary position in the compression direction by the set pressure of the relief valve, and is held in the extension direction by the oil pressure of the accumulator. When an overload (impact force) is applied to the rod extension side in this state, the rod is released while compressing the contraction side oil chamber, and at the same time, the hydraulic oil pushed from the contraction side oil chamber into the pressure accumulating chamber is released. Overload is absorbed by the resulting compression spring characteristics of the accumulator. After this release, the rod automatically returns to the initial position due to the pressure difference between the negative pressure generated in the expansion oil chamber and the hydraulic oil returning from the accumulator to the original compression oil chamber. When overload is applied to the rod compression side, the rod releases while compressing the expansion oil chamber.In this case, the hydraulic oil in the expansion oil chamber pushes the relief valve open and flows into the accumulator chamber. At this time, the overload is absorbed even on the compression side due to the resistance force received by the relief valve and the compression spring characteristics of the accumulator. (Embodiment) FIG. 1 is a sectional view showing an embodiment of the present invention, wherein 1 is a cylinder body, 2 is a piston which can slide freely in the cylinder body 1,
3 is a rod connected to the piston 2. An oil chamber 4 on the rod compression side and an oil chamber 5 on the rod extension side are defined in the cylinder body 1 via the piston 2.
Ports 6 and 7 are formed in 4 and 5, respectively. Then, an accumulator 9 in which a predetermined gas pressure is filled in the internal gas chamber 8 is provided, and a pressure accumulating chamber 11 separated from the gas chamber 8 by a free piston 10 is provided through a port 12, a pipe 13, and the port 6. The rod compression side oil chamber 4 communicates with the rod compression side oil chamber 4. The accumulator 11 is provided with a relief valve 14, a port 15 and a pipe 16.
And the port 7 is connected to the rod extension side oil chamber 5. The relief valve 14 is provided in a passage 17 between the pressure accumulating chamber 11 and the port 15.
And a spring 19 for urging the valve body 18 in the closing direction. When the oil pressure in the rod extension side oil chamber 5 exceeds a set value, the valve body 18 is moved to the spring 19 and the pressure accumulating chamber. 11
The valve is opened from the seat portion 20 of the passage 17 against the pressure on the side. 21 is a spring retainer. On the other hand, a push rod 22 is provided in front of the valve element 18 so that the relief valve 14 can be opened and closed from the outside, and a lever 24 provided with a grip portion 23 at the shaft end of the bush rod 22 is attached. The push rod 22 is screwed and supported coaxially with the valve body 18 via the base 25 of the accumulator 9.
When the push rod 22 is depressed by rotating in a predetermined direction, the relief valve 14 is forcibly opened. Reference numeral 26 denotes a snap ring for preventing the push rod 22 from coming off, and reference numerals 27 to 31 denote seals. In such a configuration, when the lever 24 is rotated in a predetermined direction from the illustrated state and the push rod 22 is pushed in, the relief valve 14 is opened, and the pressure accumulator chamber 11, the rod compression oil chamber 4, and the rod extension side of the accumulator 9 are opened. All the oil chambers 5 are in communication. Therefore, when an external force is applied between the rod 3 and the cylinder body 1, the rod 3 moves toward the extension side or the contraction side depending on the direction of the external force. At this time, the pressure in the pressure accumulating chamber 11 acts on the rod extension side due to the difference in the effective pressure receiving area of the piston 2. obtain. Then, after moving the rod 3 to an arbitrary position,
When the push rod 22 is returned to the original position by rotating the pump 24 in the original direction, the relief valve 14 is closed, and the rod extension side oil chamber 5 is isolated from the pressure accumulation chamber 11 and the rod compression side oil chamber 4. For this reason, the rod 3 is locked in the compression direction by the set pressure of the relief valve 14, while the pressure in the pressure accumulation chamber 11 is applied to the rod compression side oil chamber 4, so that the rod 3 is held by the pressure in the pressure accumulation chamber 11 in the extension direction. It will be in the state of being. Thereby, the rod 3 is fixed at an arbitrary position. Therefore, when used for an outboard motor, the outboard motor can be set at a desired angle, and when used for each device other than the outboard motor, each device must be set at an arbitrary position. Is possible. On the other hand, if an overload (impact force) is applied to the rod extension side in a state where the rod 3 is fixed (used state), the impact causes the rod 3 to release and the rod compression side oil chamber 4 is compressed. Since the rod compression oil chamber 4 and the pressure accumulating chamber 11 are always open, the hydraulic oil in the oil chamber 4 enters the pressure accumulating chamber 11. The hydraulic oil entering the accumulator 11 causes the accumulator 9
Is compressed, and the overload on the extension side is absorbed and reduced by the action of the compression spring. After the overload is removed, the rod-extension-side oil chamber 5 has a negative pressure due to the displacement of the piston 2, whereas the rod-compression-side oil chamber 4 has the pressure-accumulation chamber 11 of the accumulator 9.
High pressure acts on the rod compression side oil chamber 4
The rod 3 is automatically returned to the original position before the impact while pushing the hydraulic oil from 11. When an overload is applied to the rod contraction side, the rod 3 is released while compressing the rod extension side oil chamber 5. In this case, the hydraulic oil in the rod extension side oil chamber 5 pushes the relief valve 14. Open and enter the accumulator chamber 11 (and the rod compression side oil chamber 4). Therefore, a resistance force is generated when the hydraulic oil in the oil chamber 5 passes through the relief valve 14, and the overload on the compression side is absorbed and mitigated by the resistance force and the compression spring characteristics of the accumulator 9 accompanying the inflow of the hydraulic oil. It During the release operation to the contraction side, the extension side oil chamber 5
Hydraulic fluid remains flowing out to the pressure accumulating chamber 11 side, so that the rod 3 does not automatically return. FIG. 2 shows another embodiment of the present invention.
Is formed in a pipe shape, and the accumulator 33 is integrally formed inside the rod 32. The gas chamber 34 and the accumulator chamber 35 of the accumulator 33 are separated by a free piston or the like, but may not be separated as shown in the figure depending on the mounting direction of the cylinder. The accumulator 33 of the accumulator 33 has a piston
It is connected to a rod contraction side oil chamber 39 via a hole 38 formed in a connecting portion 37 between the rod 36 and the rod 32, and to a rod extension side oil chamber 41 via a relief valve 40 provided inside the piston 36. On the other hand, a check valve 42 is provided in the relief valve 40, and a push rod 43 is disposed coaxially with the check valve 42 so as to penetrate the rod 32. The push rod 43 is formed such that the rear end portion 44 thereof projects somewhat from the front end portion 45 of the rod 32, and a lever 47 whose one end is supported by a pin 46 is arranged opposite to this, and the lever 47 is a cylinder. When pulled toward the main body 48, the check valve 42 is opened via the push rod 43. Reference numeral 49 denotes a spring retainer, which also serves to support the push rod 43. Therefore, when the rod 32 is set at an arbitrary position, the lever 47 may be operated in the same manner as in the above-described embodiment, and the same operation as in the above-described embodiment can be obtained even when overloading after setting. If the accumulator 33 is integrally formed on the cylinder side as described above, the structure becomes compact, and the assemblability is improved. (Effects of the Invention) As described above, according to the present invention, the accumulator accumulator chamber is opened to the rod compression side oil chamber, and the accumulator chamber is also set to the rod extension side oil chamber so that the pressure of the hydraulic oil in the oil chamber is the set value. In addition to connecting via a relief valve that opens at the above time, and a lever that forcibly opens and closes this relief valve is provided, so that the rod can be set at any position and it can be set on either the extension side or the contraction side. An overload can be absorbed and a cylinder suitable as a positioning and supporting member can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view showing another embodiment of the present invention. 1 ... cylinder body, 2 ... piston, 3 ... rod,
4 ... Rod compression side oil chamber, 5 ... Rod extension side oil chamber, 9 ...
Accumulator, 11 ... Pressure accumulator, 14 ... Relief valve,
24 Lever, 32 Rod, 33 Accumulator, 35 Accumulator, 36 Piston, 39 Rod compression side oil chamber, 40 Relief valve, 41 Rod expansion side oil chamber, 47…
…lever.

Claims (1)

(57) [Claims] A piston with a rod connected to the cylinder body is slidably housed to define a rod extension side oil chamber and a rod contraction side oil chamber, while an accumulator for pressurizing hydraulic oil is provided. Opening the compression side oil chamber, the pressure accumulation chamber is connected to the rod expansion side oil chamber via a relief valve that opens when the pressure of the hydraulic oil in the oil chamber is equal to or higher than a set value, and the relief valve is forcibly opened. A cylinder provided with a lever for opening and closing.