JPH044307A - Hydraulic cylinder circuit - Google Patents

Abstract

PURPOSE:To prevent deterioration of oil and facilitate replacement of the oil by providing a bypass circuit, which connects two ports situating on the head side and on the rod side, respectively, of a hydraulic cylinder, and providing a valve, which closes and opens the said circuit, to the bypass circuit, thereby making the oil within the piping circulate. CONSTITUTION:A bypass circuit 10 is provided to pipes 7, 8 at the places near a head-side port and a rod-side port, respectively, of a lock cylinder 1, and a solenoid-type closing valve 11 is provided to the circuit 10. Usually, the bypass circuit 10 is closed, and the expansion and contraction of the cylinder 1 is controlled by a control valve 2. When the oil within the pipe is to be circulated, the bypass circuit 10 is opened, while the control valve 2 is set at the working position. Since the oil within the pipe thus circulates through the pipes 7, 8 via the bypass circuit 10, deterioration of the oil can be restricted, and moreover the oil can be kept clean by means of a filter 13 within a hydraulic unit 4. When a tank 6 in the unit 4 is renewed, the pipe for the tank is connected to a tank for drainage, and when the bypass circuit 10 is opened, dirty oil is discharged into the drain tank, and fresh oil is introduced into the pipe passage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydraulic cylinder circuit used in a branching device of a floating railway.

[Conventional technology]

The prior art will be explained by taking as an example a hydraulic cylinder circuit used in a branching device of a floating railway.

First, an overview of a branching device in a floating railway will be explained with reference to FIG.

A is the main guideway line, B is the guideway side line, and the floating vehicle C passes along the guideway main line A during normal travel, and uses the branch line when stopping at an intermediate station or evacuating to wait for a following vehicle to pass. Pass through the road and enter guideway side track B.

The branch line is constructed by connecting a plurality of branch girders d... with pins in the vehicle traveling direction between a branch line starting point S and a branch line ending point E. This branch track is switched between a straight line state when the guideway is running on the main line and a curved state when the guideway is running on the side track as shown in the figure, using the starting point S side as a fulcrum. A and a terminal branch girder d□ are connected to the guideway side line B in a curved state, respectively.

Each branch digit d1. d... are each supported on the upper surface of the support girder R via a truck and a rail (not shown), and are moved between the straight line state and the curved state as described above by the movement of this truck. In addition, each branch girder d,, d... is provided with side guide rails (not shown) on the upper surfaces of the left and right side walls to allow the vehicle C to move smoothly along the branch line using guide tires when not floating. ) is provided.

Such a branching device includes a truck drive cylinder for moving each of the trucks, a jack cylinder for adjusting each side guide rail into a curved shape when the branch line is curved,
Each branch digit d1. Numerous hydraulic cylinders, such as lock cylinders for fixing and unfixing d... to the guideway road surface, connection cylinders for connecting the terminal branch girder d□ to the guideway main line A or guideway side line B, etc. is used.

A conventional hydraulic circuit for driving a cylinder in this branching device is shown in FIG. 6, taking the case of a lock cylinder as an example.

Lock cylinders are installed on both the left and right sides of each branch girder, and these are separated by separate control valves (
Expansion and contraction (locking, unlocking) is controlled by the electromagnetic switching valve) 2... 3 are these control valves 2...
4 is a hydraulic unit equipped with a hydraulic pump 5 and a tank 6, etc., 7 and 8 are piping on both the head side and rod side connecting this hydraulic unit 4 and the lock cylinder, and 9 is other piping. Distribution piping for the cylinder circuit, 13 is a filter.

[Problem to be solved by the invention]

In such a hydraulic cylinder circuit, the pipe length (the length of the pipes 7 and 8) is about ten meters one way, and the amount of oil moved by the operation of the cylinder is small. Therefore, the oil in the cylinder and its surrounding piping only moves in and out of the cylinder 1 every time the cylinder is pushed or pulled, that is, reciprocates over a fixed short section, so this part is not replaced at all.

In this way, if the oil in the cylinder and surrounding piping remains stagnant forever, the oil in this area will deteriorate. Furthermore, since this cylinder and its surrounding piping are outdoors and exposed to high temperatures in the summer and low temperatures in the winter, the oil is particularly susceptible to deterioration, and there is also a risk of moisture separation and the intrusion of foreign matter.

However, in the past, no means had been taken to actively circulate the oil in these pipes, so the lubricating function was lost due to deterioration of the oil, damage to the seals, etc. occurred, and the operation of the cylinder was interrupted. In other words, there was a risk that the fixing/unfixing operation of the branch line would be disrupted.

On the other hand, in order to control the quality of the oil, especially the viscosity, it is necessary to change the oil periodically or depending on the season.

However, in the conventional circuit, although it is possible to change the oil in the hydraulic unit 4, replacing the oil in the pipe lines requires removing the oil from many cylinders and pipes 7 and 8, and having to replace the oil with new oil. It has become extremely difficult to bleed air out of the air.

This made it difficult to control the quality of the oil, which led to problems with the reliability of the shilling operation.

Such problems occur not only in the lock cylinder circuit but also in other cylinder circuits in the branching device. In particular, floating railway branching devices require (I) rapid switching operations in seconds, so reliability of cylinder operation (including constant speed) is important; (II) extremely large number of Because it is controlled by the combined operation of the cylinders, malfunction of one cylinder cannot be tolerated. Therefore, oil quality control (prevention of air and dirt entrapment and deterioration of quality, and maintenance of speed) is necessary. viscosity management) has become important, and an early solution to the above problem has been awaited.

SUMMARY OF THE INVENTION The present invention provides a hydraulic cylinder circuit that actively circulates oil within a pipe line to suppress oil deterioration and facilitates oil exchange.

[Means to solve the problem]

The present invention provides a hydraulic cylinder circuit in which a hydraulic cylinder is connected to a pump and a tank via a control valve, in which a bypass circuit is provided that short-circuits both the head side and rod side ports of the hydraulic cylinder, and the bypass circuit has the following features: A valve is provided to open and close the circuit (Claim 1).

Further, the invention of claim 2 is the structure of claim 1, in which the hydraulic cylinder is provided with bypass ports on both sides separately from both the head side and rod side ports, and a bypass circuit is provided between the both side bypass ports. It is something.

Furthermore, the invention according to claim 3 is based on the configuration according to claim 1 or 2, and further includes a throttle valve provided in the bypass circuit in series with a valve that opens and closes the circuit.

Further, the invention according to claim 4 is the configuration according to claim 3, in which a variable throttle valve is used as the throttle valve.

[Effect]

With the above configuration, oil in the pipe can be circulated through the bypass circuit by opening the valve periodically or at an appropriate time and operating the pump.

Furthermore, when changing the oil in the pipeline, old oil can be easily drained and new oil introduced through the bypass circuit, as described above.

Therefore, the quality control of the oil in the pipe line becomes easy, and the reliability of cylinder operation can be increased.

Claim 2 further includes a hydraulic cylinder provided with a bypass port.
According to this structure, the oil in the cylinder can be circulated or exchanged through the path circuit, so that the efficiency of circulation and exchange can be improved. In addition, by heating or cooling the hydraulic oil in the tank to maintain a constant temperature in response to changes in outside temperature, fresh hydraulic oil with the required viscosity is constantly supplied to the cylinder, ensuring constant operating speed. It becomes possible to maintain

On the other hand, according to the configuration of claim 3 in which a throttle valve is provided in the bypass circuit, the temperature of the circulating oil can be increased by generating heat by the throttling action of the throttle valve, so that there is no need to rely on temperature control of the hydraulic oil in the tank. It is possible to control oil temperature using a bypass circuit and adjust the viscosity of the oil.

Therefore, the viscosity of oil can be maintained at an appropriate level, especially in cylinder circuits used under various temperature conditions depending on the season or region, such as hydraulic cylinder circuits used in branching devices of floating railways.

Further, according to the fourth aspect of the invention, in which a variable throttle valve is used as the throttle valve, the oil temperature (viscosity) can be controlled efficiently.

〔Example〕

Embodiments of the present invention will be described with reference to FIGS. 1 to 4.

First Embodiment (See Figures 1 and 2) In accordance with the conventional explanation, this embodiment is applied to a drive circuit for a lock cylinder for fixing a branch girder in a branching device of a floating railway. .

To explain only the differences from the prior art (Fig. 6), both the head side and rod side ports P1. A bypass circuit 10 is provided between both the head side and rod side pipes 7 and 8 at a position extremely close to P2.

This bypass circuit 10 is provided with an electromagnetic on-off valve 11,
The bypass circuit 10 is opened and closed by this electromagnetic on-off valve 11 (
conduction and cutoff).

The bypass circuit 10 is in the closed state shown in the figure during normal circuit use. In this state, the cylinder circuit has the same configuration as the conventional circuit shown in FIG. 5, and the control valve 2 controls the expansion and contraction of the cylinder 1.

On the other hand, when it is desired to circulate the oil in the pipe, the control valve 2 is set to any operating position with the bypass circuit 10 open.

In this way, the oil in the pipes circulates within the pipes 7 and 8 on both sides through the bypass circuit 10. Therefore, by performing this circulation periodically or at an appropriate time by checking the oil condition, deterioration of the oil in the pipes can be suppressed, and the filtration action of the filter 13 in the hydraulic unit 4 can suppress the oil in the pipes. can be kept clean.

Although the oil in the cylinder 1 does not move during this circulation, the oil in the cylinder is eventually replaced by repeating the circulation.

In addition, if you want to replace the oil in the pipeline with one of the appropriate viscosity depending on seasonal changes, or if you want to replace it with a new one depending on the lifespan, for example, you can replace the tank 6 of the hydraulic unit 4 with a new one. After replacement and with a drain tank connected to the tank piping of the same unit 4, the bypass circuit 10 may be opened in the same manner as during the circulation described above, and the oil may be allowed to flow through this bypass circuit 10. In this way, new oil is introduced into the pipe while old oil is drained into the drain tank.

Note that when changing the oil in a cylinder circuit, it is normally necessary to carry out strict air bleeding after the oil change, and in devices such as this type of branching device that have a large number of cylinders, These operations require a considerable amount of time and money.

On the other hand, according to this cylinder circuit, the oil can be replaced extremely easily and quickly as described above.

In this way, the oil in the pipe can be circulated and the oil can be easily replaced, so that the quality (viscosity, etc.) of the oil in the pipe can be maintained at an appropriate level. Therefore, it is possible to prevent malfunction of the cylinder 1 due to oil deterioration or inappropriate viscosity, etc., and to improve the reliability of cylinder operation.

Second embodiment (see Figure 3) Only the differences from the first embodiment will be explained.

In the second embodiment, on the head side and rod side of the cylinder 1, both the head side and rod side ports P1. P2
Both the head side and rod side bypass ports P3. P4 is provided, and a bypass circuit 10 is provided between the bypass ports P3+P4 on both sides.

According to this configuration, during oil circulation and oil exchange, oil passes through both the head side and rod side oil chambers in the cylinder 1.
That is, since both chambers within the cylinder serve as oil circulation and exchange channels, the oil within the cylinder can be exchanged at the same time.

In addition, by heating or cooling the hydraulic oil in the tank to maintain a constant temperature in response to changes in outside temperature, fresh hydraulic oil with the required viscosity is constantly supplied to the cylinder, resulting in a constant operating speed. It becomes possible to maintain sex.

Third embodiment (see FIG. 4) In the third embodiment, based on the configuration of the first embodiment or the second embodiment, a variable throttle valve 12 is provided in the bypass circuit 10 in series with the on-off valve 11, The variable throttle valve 12 is configured to adjust the amount of oil passing through the bypass circuit 10.

According to this configuration, the oil temperature can be controlled by the oil squeezing (heat generation) action, so that the viscosity of the oil can be maintained at an appropriate level, for example, by circulating the oil and raising the temperature in cold weather.

Moreover, since the degree of throttling can be freely adjusted using the variable throttle valve 12, the oil temperature can be controlled quickly and accurately in accordance with the ambient temperature, etc.

Incidentally, in each of the above embodiments, a cylinder circuit used in a branching device of a floating railway was used as an example of an object to which the present invention can be most effectively applied, but the present invention has a similar problem. It can be applied to all cylinder circuits.

Further, regarding the invention of claim 3, a fixed throttle valve may be used as the throttle valve.

〔Effect of the invention〕

As described above, according to the present invention, a bypass circuit opened and closed by a valve is provided in a state where both the head side and rod side ports of the hydraulic cylinder are short-circuited. It is possible to circulate the oil in the passage. Therefore, it is possible to prevent oil deterioration caused by oil stagnation.

Furthermore, similar to the above-mentioned circulation function, old oil can be discharged and new oil introduced through the bypass circuit, making it easy to replace the oil according to the lifespan of the oil or seasonal changes.

These points make it easier to control the quality of the oil and improve the reliability of cylinder operation.

Claim 2 further includes a hydraulic cylinder provided with a bypass port.
According to this configuration, the oil in the cylinder can also be circulated or exchanged through the bypass circuit, so that the efficiency of circulation and exchange can be improved. This oil circulation mechanism also applies to systems that control the viscosity of the hydraulic oil to maintain a constant oil temperature, or speed, by heating or cooling the hydraulic oil in the tank in response to changes in outside temperature. works extremely effectively.

Furthermore, according to the structure of claim 3 in which the bypass circuit is provided with a throttle valve, the temperature of the circulating oil can be increased by generating heat by the throttling action of the throttle valve. It is possible to adjust the viscosity of the oil.

Further, according to the fourth aspect of the invention, in which a variable throttle valve is used as the throttle valve, the oil temperature (viscosity) can be controlled efficiently.

[Brief explanation of drawings]

Fig. 1 is a hydraulic cylinder circuit diagram showing a first embodiment of the present invention, Fig. 2 is a partially enlarged view of Fig. 1, and Fig. 3 is a hydraulic cylinder circuit diagram showing a first embodiment of the present invention.
Embodiment, FIG. 4 is a view corresponding to FIG. 2 showing the third embodiment, and FIG. 5 is a schematic perspective view for explaining the outline of a branching device for a floating railway as an example to which the present invention is applied. 6 are conventional hydraulic cylinder circuit diagrams. 1... Hydraulic cylinder, 2... Control valve,
3... Valve stand, 4... Hydraulic unit, 5...
...Pump, 6...Tank, 7,8...Both head side and rod side piping, 9...Distribution piping for other cylinder circuits, 10...Bypass circuit, 11...Same bypass circuit Valve for opening and closing, 12... Variable throttle valve, 13
···filter.

Claims (1)

[Claims] 1. A hydraulic cylinder circuit in which a hydraulic cylinder is connected to a pump and a tank via a control valve,
A hydraulic cylinder circuit characterized in that a bypass circuit is provided to short-circuit both the head side and rod side ports of the hydraulic cylinder, and the bypass circuit is provided with a valve that opens and closes the circuit. 2. The hydraulic cylinder circuit according to claim 1, wherein the hydraulic cylinder is provided with both side bypass ports in addition to both the head side and rod side ports, and a bypass circuit is provided between the both side bypass ports. 3. Claim 1 or 2, characterized in that the bypass circuit is provided with a throttle valve in series with a valve that opens and closes the bypass circuit.
Hydraulic cylinder circuit as described. 4. The hydraulic cylinder circuit according to claim 3, wherein the throttle valve is a variable throttle valve.