JPS6213807A - Fluid pressure cylinder device - Google Patents

Abstract

PURPOSE:To obtain a cylinder device capable of retaining members safely even if oil pressure falls suddenly by bringing the first piston into contact with the second piston having a given buffering pressure when the first piston is excessively slidably moved by an external force in lieu of a rod. CONSTITUTION:The first piston 14 connected by a rod 16 is housed in a cylinder body 11, and an oil pressure supply pipe 20 is communicated with a cylinder chamber 12 on the rod side. On the other hand, at the lower stroke end of the first piston 14, the second piston 15 is arranged, and a drain passage is communicated with a cylinder chamber 13 thereunder via a relief valve 21. When the oil pressure in the oil pressure supply pipe 20 falls suddenly to move the rod 16 downward, the first piston 14 comes in contact with the second piston 15, thus the rod 16 can be retained at the set pressure of the relief valve.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a fluid pressure cylinder device, and in particular a fluid pressure cylinder used as a horizontal holding device when moving or launching a long structure such as an immersed pipe. It is related to the device.

(Prior Art) There is a device shown in FIG. 3 as a horizontal holding device for this type of long structure. This device attaches each existing cylinder 1 consisting of a plurality to a portal crane (not shown), etc., and suspends each part of the immersed pipe 4 in the longitudinal direction with a wire 3 tightly attached to the rod 2 of each cylinder 1. At the same time, fluid pressure is supplied into the cylinder chamber of each cylinder 1 via the communication pipe 5 to urge the piston in the direction of pulling up the submerged pipe 4.

(Problems to be Solved by the Invention) However, according to the above-mentioned conventional technology, when, for example, a part of the communication pipe 5 is damaged and the fluid pressure that biases the piston is reduced, the cylinder that bottoms out first Excessive force may be applied to the gantry crane and the immersed pipe 4, causing danger to workers. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve these drawbacks and provide a fluid pressure cylinder device that can be stably maintained even if a portion of the communication pipe is damaged.

(Means for Solving the Problems) The gist of the present invention is that when the first piston is excessively slid due to an external force applied to the rod, the rod comes into contact with the first piston to counteract this. A hydraulic cylinder device with a second biased piston.

(Example) Examples of the present invention will be described below based on the drawings. 1st
The figure shows the configuration of a fluid pressure cylinder device 10, in which a cylinder main body 11 includes first cylinder chambers 1 that communicate with each other.
2 and a second cylinder chamber 13 are provided. A first piston 14 is located within the first cylinder chamber 12).
A second piston 15 is mounted in the second cylinder chamber 13 so as to be movable. A rod 16 connected at one end to the first piston 14 is connected to the second piston 14.
The other end extends through the cylinder chamber 13 and protrudes from the cylinder main body 11, and the other end has a fastening part 1 such as a wire.
7 is formed. The second piston 15 is slidably wound around the middle portion of the rod 16. Note that the outer circumference of the first piston 14 and the second piston 15
Seal members are provided at each sliding portion such as the inner and outer peripheries of the cylinder body 11 and the opening edge from which the rod 16 of the cylinder main body 11 projects.

Further, the cylinder main body 11 is provided with a first port 18 and a second port 19, and the first port 18 is connected to another fluid pressure cylinder via a communication pipe 20. At the same time, a fluid pressure P1 that biases the first piston 14 in the direction of separating it from the second piston 15 is supplied to the first cylinder chamber 12 by a fluid pressure source (not shown) common to each fluid pressure cylinder. . Further, the second port 19 is connected to a relief valve 21, and the fluid pressure P2 that urges the second piston 15 toward the first piston 14 is transferred to the second cylinder chamber 1.
Supply to 3.

The fluid pressure P1 is normally set to a constant pressure that can resist the external force that tries to pull down the rod 16, and the fluid pressure P2 is larger than the fluid pressure P1, so that the first piston 14 pulled down by the excessive external force When the piston 15 comes into contact with the piston 15, the pressure is set at a constant pressure that can at least counteract the bottoming out.

Next, the operation of the horizontal holding device for an immersed pipe, which is constructed by arranging the above-mentioned fluid pressure cylinder devices 10 in parallel, will be explained based on FIG. 2. FIG. 2(a) shows each part of the immersed pipe 22 in each fluid pressure cylinder device 10a.

10b and 10c are suspended by the tension parts 17a, 17b, and 17c provided at the ends of the rods 16a, 16b, and 16C, and the first cylinder chamber 12 has a common fluid. Pressure P1a, P1b, p1
c is supplied. If the part 20a of the communication pipe 20 is damaged as shown in FIG. 14b
counteracts with the set pressure P2b of the relief valve 21b to prevent the first piston 14b from descending. Each fluid pressure cylinder device 10a follows the fluid pressure cylinder device 10b,
The pistons 14a and 14C of the 10C multi-cylinder 1 descend one after another as shown in FIG. 2(C), and the relief valves 21a and 21
C opposes each piston 14a and 14C with set pressures P2a and P2C, respectively, and prevents the pistons 14a and 14C from descending, so that the submerged pipe 22 is stably maintained in a horizontal state without bottoming out. Thereafter, as shown in FIG. 2(d), the damaged part 20a of the communication pipe 20 is repaired, and each fluid pressure cylinder device 10a,
10b, 10c second ports 19a, 19b,
19c from the second fluid pressure source 23.
The second piston 1 is supplied with a larger fluid pressure P3.
5a, 15b, 15C as the second cylinder chamber 13a,
Raise and return to the upper ends of 13b and 13c. The fluid pressure source 24 then connects each port 18a, 18b, 18c.
Constant fluid pressures Pa, Pb, and Plc are supplied from the pistons 14a, 14b, and 14c, respectively, to raise and return the first pistons 14a, 14b, and 14c to predetermined positions.

(Effects of the Invention) As is clear from the above embodiments, the fluid cylinder device of the present invention can prevent the piston from sliding due to excessive external force. When used in equipment that is suspended and held horizontally, it is possible to stably hold the load even if the communication pipe is damaged, and there is no risk of damaging the gate crane or submerged pipe or posing a danger to workers. This is useful as a safety mechanism to prevent this.

[Brief explanation of the drawing]

The drawings all show embodiments of the present invention; Fig. 1 is a configuration diagram of a fluid pressure cylinder device, Fig. 2 is an explanatory diagram of the operation of a horizontal holding device for a long structure using the same device, and Fig. 3 is a horizontal holding device according to a conventional example. FIG. 3 is a side view of the holding device. [Explanation of symbols] 10...Fluid pressure cylinder device 11...Cylinder body 12...First cylinder chamber 13...Second cylinder chamber 14...First piston chamber 15...・Second piston chamber 16...rod 17...tight part 18...
・First port 19...Second port 20...Communication pipe 21...Relief valve 22...Immersed pipe

Claims (1)

[Claims] First and second cylinder chambers communicating with each other are provided in the cylinder, a first piston is slidably mounted in the first cylinder chamber, and a rod is connected at one end to the first piston. The end extends through the second cylinder chamber and protrudes to the outside, and the outer periphery of the rod has a part inside the second cylinder that opposes the first piston when it slides excessively. A second piston is wound around the cylinder, and a first piston is provided with fluid pressure from outside so as to urge the first piston in a direction to separate it from the second piston. A fluid pressure cylinder device comprising: a port; and a second port for supplying fluid pressure from the outside so as to urge the second piston toward the first piston.