JP4100647B2 - Oil damper - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an industrial oil damper that cushions a suspended load suspended from a container crane or an overhead crane, and in particular, when the suspended load performs a pendulum motion, the oil damper is locked to absorb the potential energy of the suspended load. The present invention relates to an improvement of a uniflow type oil damper that suppresses vibration.
[0002]
[Prior art]
Conventionally, this type of oil damper OD mainly comprises inner and outer cylinders 1 and 2 and front and rear lids 3 and 4 as shown in FIG. 3, and is surrounded by inner and outer cylinders 1 and 2 and front and rear lids 3 and 4. A reservoir chamber R is formed, and a piston 7 fastened to a piston rod 6 is slidably fitted into the inner cylinder 1 to define oil chambers Ra and Rb. 1 slidably protrudes from the front lid 3 through an oil seal 9, a seal member 10, and a bearing member 11 provided on the front lid 3.
[0003]
The rear cover 4 provided at one end of the inner cylinder 1 is provided with a check valve CH1 that allows only oil flow in one direction from the reservoir chamber R to the oil chamber Rb, and the piston 7 has a passage 7a provided in the piston 7. A check valve CH2 that allows only one-way oil flow from the oil chamber Rb to the oil chamber Ra is provided.
[0004]
The front lid 3 is provided with a port p1 communicating with the oil chamber Ra, and the rear lid 4 is provided with a port p2 communicating with the reservoir chamber R and the oil chamber Rb via the check valve CH2. A logic valve V3 and a pilot valve V4 that generate a damping force are disposed in a pipe line t1 that connects p1 and the port p2.
[0005]
In the logic valve V4, a valve body v biased by a spring f is inserted, and on the primary side, pressure is introduced into the pilot chamber pr from a port p1 through a throttle r provided in the valve body v. The secondary side is connected to the pipe line t1, and the pilot chamber pr is connected to the pilot valve V4.
[0006]
The pilot valve V4 is an electromagnetic two-port two-position switching valve. The back pressure in the pilot chamber pr of the logic valve V3 is communicated with or cut off from the low-pressure side reservoir chamber R to open and close the logic valve V3.
[0007]
And when the suspended load performs a pendulum motion, the pilot valve V4 is remotely operated to shut off the logic valve V3, the oil damper OD is locked, the potential energy of the suspended load is absorbed, and the vibration is suppressed. There is something.
[0008]
[Problems to be solved by the invention]
However, in the oil damper of the above conventional example, when the logic valve is opened and closed, the self-pressure generated on the back surface of the valve body is set as the pilot pressure, and is opened and closed by releasing to the low pressure side through the pilot valve. In particular, when the logic valve is closed, the pilot chamber pressure rises poorly due to the restriction provided in the valve body, and a delay in response occurs until the valve closes. There was a problem that could not be demonstrated.
[0009]
Therefore, the present invention was created in view of the above-described circumstances, and the object of the invention is to configure a pilot operated switching valve without using a logic valve for switching the damping force. By providing an oil damper that uses the high pressure accumulated in the oil damper as a pilot pressure to speed up the switching response of the valve when the valve opens, and that the valve returns to its own when the valve is closed. is there.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the means of the first invention comprises: A reservoir chamber is defined between the outer cylinder and the inner cylinder, and a rod-side oil chamber and an anti-rod-side oil chamber are defined in the inner cylinder by a piston slidably inserted into the inner cylinder. In a uniflow type oil damper in which a main valve that generates a damping force is disposed in a conduit that communicates with each oil chamber so as to be freely opened and closed, the main valve includes a spring that urges the main valve in a closing direction, A pilot valve that guides the pilot pressure against the spring, and the main valve is opened using the pressure accumulated in the rod-side oil chamber and the non-rod-side oil chamber as a pilot pressure. The main valve is closed by returning by the spring .
[0011]
In the second invention, the main valve is a pilot operated 2-port 2-position switching valve.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS.
In this case, the above-mentioned names and symbols are used for the same configuration as the conventional example.
As shown in FIG. 1, the basic structure of the oil damper OD according to this embodiment is that a reservoir chamber R is defined between the outer cylinder 2 and the inner cylinder 1 and is slidable in the inner cylinder 1. The inserted piston 7 defines a rod-side oil chamber Ra and an anti-rod-side oil chamber Rb in the inner cylinder 1, and generates a damping force in a pipe t1 that communicates the oil chambers Ra and Rb. This is a uniflow type oil damper in which the valve V2 is arranged to be freely opened and closed.
In the present invention, the main valve V2 includes a spring S that urges the main valve V2 in the closing direction and a pilot valve V1 that guides a pilot pressure against the spring S, and the rod-side oil chamber Ra. The main valve V2 is opened using the pressure accumulated in the anti-rod side oil chamber Rb as a pilot pressure, and when the pressure decreases, the main valve V2 is closed by being returned by the spring S.
This will be described in more detail below.
[0013]
As shown in FIG. 1, an oil damper (hereinafter referred to as a damper) OD according to this embodiment mainly comprises inner and outer cylinders 1 and 2, front and rear lids 3 and 4 and the like. The reservoirs R are concentrically supported and coupled by the bodies 3 and 4, and are surrounded by the inner and outer cylinders 1 and 2 and the front and rear lids 3 and 4.
[0014]
Further, a piston 7 fastened to the piston rod 6 is sealed in the inner cylinder 1 by a seal member 8 and is slidably inserted to partition oil chambers Ra and Rb.
[0015]
The piston rod 6 protrudes slidably from the front lid 3 through an oil seal 9, a seal member 10, and a bearing member 11 provided on the front lid 3.
[0016]
The piston 7 is provided with a check valve CH <b> 2 that allows only a one-way oil flow from the oil chamber Rb to the oil chamber Ra in a passage 7 a provided in the piston 7.
[0017]
The rear cover 4 on one end side of the inner cylinder 1 is provided with a check CH1 that allows only an oil flow from the reservoir chamber R to the oil chamber Rb through the passage 4a.
[0018]
The front lid 3 is provided with a port p1 that communicates with the oil chamber Ra via the passage 3a, and the rear lid 4 is provided with a port p2 that communicates with the reservoir chamber R and the oil chamber Rb via the check valve CH1. A main valve V2 and a pilot valve V1 that generate a damping force are disposed in a pipe line t1 that connects the port p1 and the port p2.
[0019]
The main valve V2 is a pilot operated 2-port (a, b) 2-position (A, B) type switching valve. The port a and the port b are blocked at the position A, and the port a and the port b at the position B. Is communicated with.
[0020]
The primary side port a of the main valve V2 communicates with a port p1 provided in the front lid 3 via a pipe line t2, and the secondary side port b is connected to the low pressure side pipe line t1 so as to oppose the spring S. The pressure Pa in the oil chamber Ra is connected to the pilot valve V1 as a pilot pressure.
[0021]
The pilot valve V1 is an electromagnetic 3-port (c, d, e) 2-position (C, D) switching valve. At the position C, the port c and the ports d, e are blocked, and the port d and the port e are In the position of D, port c and port d communicate with each other, and port e is blocked.
[0022]
The primary side port c of the pilot valve V1 communicates with the port p1 provided in the front lid 3 via the pipe line t3, the secondary side port d is connected to the pilot of the main valve V2 via the pipe line t4, and the port e is It is connected to the port p2 via the low-pressure side pipe t1, and is remotely operated by an electromagnetic force that opposes the spring s.
[0023]
Next, the operation will be described.
[0024]
If the pilot valve V1 is OFF and the pilot valve V1 is in the C position, the pilot pressure introduced into the main valve V2 is lower than the pipe t4 and the ports d and e of the pilot valve V1. The main valve V2 is urged by the spring S to be in the A position, shuts off the ports a and b, and locks the damper OD.
[0025]
Therefore, when the damper OD is in a locked state and the piston rod 6 of the damper OD receives a load and a pressure Pa is generated in the oil chamber Ra, the pilot valve V1 is turned on and the pilot valve V1 is moved from the C position to the D position. When the pressure Pa is introduced as pilot pressure to the main valve V2 from the ports c and d of the pilot valve V1 through the pipe line t4, the main valve V2 is moved to the spring position as shown in FIG. Switched from the A position to the B position against S, the pressure Pa in the oil chamber Ra of the damper OD is secondary through the port p1, the pipe t2, the ports a and b of the main valve V2, and the pipe t1. The damper OD changes from the locked state to the free state while the damping chamber OD escapes while generating a damping force.
[0026]
When the pressure Pa as the pilot pressure introduced into the main valve V2 decreases and becomes smaller than the spring force of the spring S of the main valve V2, the main valve V2 moves from the switching position D to the position C of the pilot valve V1. Regardless of the operation delay, the spring force of the spring S returns the position B to the position A, and as shown in FIG. 2B, the ports a and b are closed, and the damper OD is again locked.
[0027]
In this way, the valve that generates the damping force disposed in the pipe line t1 that communicates the oil chambers Ra and Rb is constituted by the pilot valve V1 and the main valve V2, and the high pressure Pa in the oil chamber Ra is set to the pilot valve V1. When the main valve V2 is opened and the main valve V2 is opened, the pressure Pa in the oil chamber Ra accumulated in the damper OD is used as a pilot pressure. When the main valve V2 is closed, the main valve V2 is returned by the self-spring S of the main valve V2. Since the main valve V2 is opened and closed, and the pipe line t1 communicating with the oil chambers Ra and Rb is communicated and cut off, the pressure Pa generated in the oil chamber Ra is used as a pilot pressure when the main valve V2 is opened. The damper OD is switched from the locked state to the free state, and when closed, the damper OD is returned by the spring force of the self spring S of the main valve V2, and the switching position D of the pilot valve V1 The damper OD regardless of the operation delay of the al position C a faster switching response to the lock state from the free state, absorbs the potential energy of the suspended load, it is possible to suppress vibration.
[0028]
In addition, since the main valve V2 and pilot operated 2-port (a, b) 2-position (A, B) type switching valve are used, a commercially available switching valve can be used without any special specification. Is available at a low cost and can be reduced in cost.
[0029]
【The invention's effect】
According to the first invention, the reservoir chamber is defined between the outer cylinder and the inner cylinder, and the rod-side oil chamber and the anti-rod are placed in the inner cylinder by the piston slidably inserted into the inner cylinder. A uniflow type oil damper that defines a side oil chamber and in which a main valve that generates a damping force is disposed in a pipe line that communicates with each oil chamber so as to be openable and closable. And a pilot valve that guides the pilot pressure against the spring, and the main valve is operated using the pressure accumulated in the rod side oil chamber and the anti-rod side oil chamber as a pilot pressure. open, because the pressure is allowed to return by the spring when the decreased to close the main valve, the switching of the oil damper regardless of the operation delay of the switching position of the pilot valve from the free state to the lock state For example a faster response, for example, when used in industrial oil damper for buffering the suspended load that hung on a crane, absorbs potential energy of the suspended load, there is an effect that it is possible to suppress the vibration.
[0030]
According to the second invention, the portion corresponding to the valve that generates the damping force is made the main valve and the pilot operated 2 port (a, b) 2 position (A, B) type switching valve. Since a commercially available switching valve can be used without any change, it can respond quickly to changes in specifications and can be obtained at low cost, thereby reducing costs.
[Brief description of the drawings]
FIG. 1 is a front sectional view of an oil damper illustrating an embodiment of the present invention.
2 (a) is an explanatory view for explaining a main valve opening operation of the oil damper in FIG. 1; FIG.
(B) It is explanatory drawing explaining the close time of the main valve in the oil damper in FIG. 1 similarly.
FIG. 3 is a front sectional view showing an oil damper according to a conventional example.
[Explanation of symbols]
1 Inner cylinder 2 Outer cylinder 3 Front lid 3a, 4a, 7a Passage 4 Rear lid 6 Piston rod 7 Piston 8, 10 Seal member 9 Oil seal 11 Bearing member A, B Main valve position C, D Pilot valve position CH1, CH2 Check valve OD Oil damper Pa Pressure Ra in oil chamber Ra, Rb Oil chamber R Reservoir chamber S Main valve spring V1 Pilot valve V2 Main valve a, b Main valve port c, d, e Pilot valve port p1 Front Port p2 provided on the lid Port s provided on the rear lid Spring t1 to t4 of the pilot valve Pipe line

Claims (2)

 A reservoir chamber is defined between the outer cylinder and the inner cylinder, and a rod-side oil chamber and an anti-rod-side oil chamber are defined in the inner cylinder by a piston slidably inserted into the inner cylinder. In a uniflow type oil damper in which a main valve that generates a damping force is disposed in a conduit that communicates with each oil chamber so as to be freely opened and closed, the main valve includes a spring that biases the main valve in a closing direction, A pilot valve that guides the pilot pressure against the spring, and the main valve is opened using the pressure accumulated in the rod-side oil chamber and the non-rod-side oil chamber as a pilot pressure. An oil damper that is returned by the spring and closes the main valve.  The oil damper according to claim 1, wherein the main valve is a pilot operated two-port two-position switching valve.

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