JPH06508424A - multistage hydraulic cylinder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] multistage hydraulic cylinder The multi-stage hydraulic cylinder of the present invention and the load #5 of this multi-stage land pressure cylinder This invention relates to a method of moving a load with different stroke lengths (back pressure) and different stroke lengths.

Multistage hydraulic cylinders for moving loads are known in principle.

However, do nested cylinders with a well-known structure based on a general concept have any drawbacks? Cylinder In addition to the structural length, space is also required for the required support structure. Furthermore, nested Siri All parts of the cylinder are capable of absorbing the amount generated by each cylinder stage. It must be configured accordingly. If the difference in force between individual cylinder stages is large, the input This characteristic of lever cylinders necessarily makes the cylinder design expensive. .

What is the problem of this invention? Have a small ma--as much as 71% as possible*-'r -Hold it! It is cheaper to manufacture than known types of multi-stage lifting cylinders and can be used for various load systems and Is it possible to move the load by changing the stroke length? By providing multi-stage hydraulic cylinders Ru.

This II solution is implemented as indicated in the I patent claims.

Thus, in response to this task, a high pressure can be generated with a short stroke length in the first stroke stage. A multi-stage hydraulic cylinder capable of This first stroke stage is a t hollow piston It is based on the well-known principle of a hollow cylinder, in which the load is supported on a hollow piston. Ru. According to the invention, this hollow piston has multiple pistons disposed inside it at the same time. It is configured to be a cylindrical tube of a lever type cylinder.

In the example, when pressure is applied to the connecting short pipe of the first stroke stage during the initial stroke motion, ? Move large loads. What is this load? Specific starting resistance (breakaway resistance) It consists of an increased physical load. After the short stroke within the kl stroke stage! Starting resistance is overcome and only the load is transferred at different stages of the stroke motion. Just let it happen. For this reason, stroke stages II and III are pressurized at the pressure medium connection. Ru. In the example, the piston of stage II+ moves to the load and takes it on. Ru. Stages II and III advance to finally move the load to its terminal position. .

For example, when a three-stage lifting cylinder is retracted or lowered, it receives only one lower back pressure or load. Each stage of such a hydraulic cylinder, which must then be returned to its desired end position, is 26.0}-ton weight hearth electrode after appropriate wear or burnout + IK furnace refractory In order to push the material out of the hearth lined with material and push it into the inside of the furnace chamber, it is raised and lowered in 1 and 3 steps. It can be used as a device in a DC arc furnace.

Peel off the hearth electrode that is stuck to the hearth and sintered and tamped! Only about 300am The pressure to be applied in the first stage of the three-stage device for the entire waiting tank is approximately 100 tons. There are times when it becomes. In the second and third stages, the stripped hearth S pole The unloading equipment, such as a crane, is used to pick it up and transport it to the storage area or repair shop in the I-Wani factory building. ? To lower it there + two internal lifting cylinders (stage II and rxt) approx. You can only lift 20001111.

The invention is explained in the drawings on the basis of an embodiment illustrating the principle. FIG. 3 is a sectional view of a three-stage lifting cylinder.

Figure 2 is Dan! Figure 3 is a cross-sectional view of the three-stage lifting cylinder in the advanced state. A sectional view of an elevating cylinder.

Figure 4 is 1! Figure 3 shows a three-stage lifting cylinder located below the hearth electrode of a flowing arc furnace.

The hydraulic cylinder shown in FIGS. 1 to 3 is a three-stage cylinder.

The first cylinder stage I includes a cylindrical tube (11) and a piston (2) inside. It is constructed as a hollow piston type cylinder with a hollow piston rod (3). Ru.

Two long stroke cylinders (4+6) are nested inside the hollow piston rod (3). It is placed as a driver.

Hollow piston rod (3)! Stroke limiter for pre-filled piston (4) of stage II (5) and insert the pre-prepared piston (4) into the nesting cylinder (6) for stage III. Travel restrictions for! (7) is included.

The cylindrical pipe (11 has a ν stage ■ ascending pressure medium connection port (8) and descending pressure medium connection port ( There are 9 stations. Pressure medium connections (10+11) for stages II and III are ■Bottom of hollow piston rod (3) (for lifting) and above of 9 hollow piston rod (3) It is located next to the area (for descent).

(I3) is a stationary support, and the cylinder of stage ■ can be supported on this support. Wear.

FIG. 1 shows the three-stage lifting cylinder in its advanced state.

In FIG. 2, the hollow piston rod (3) extends upward as a step (3).

Figure 3 shows the three-stage lifting cylinder in its fully extended state; Linda (416) has advanced to the stroke limit portion.

1 to 3, the present invention is used as a lifting cylinder for lifting and lowering a load (I2). The use of hydraulic cylinders is generally indicated. The device according to the invention basically Of course, it can also be used to move loads in other directions.

Figure 4 shows the use of a three-stage lifting device in a practical example! In other words, as stated in the preface of the detailed bud. This shows the use for volatilizing the hearth 1s pole from the hearth of a DC arc furnace.

The hearth electrode (14) is located in the hearth of the DC arc furnace and is replaced after wear or repaired. replaced with a new hearth electrode. placed around the hearth electrode under the furnace vessel and connected to the furnace from below. A multistage cylinder (16) pressed against the bottom plate (15) of the 11-pole floor (14) According to claim 5, nine hearth electrodes are located at the top of two hollow piston type cylinders (b2+3). Initially, it is acted upon by a pressure medium at a high back pressure (26 tons in weight of the hearth electrode). This is it so that the hearth electrode (14) is separated from its bond with the surrounding hearth refractory. It can be done. Next is the long stroke cylinder.

Lift the hearth electrode into the arc furnace vessel with low back pressure. Worn hearth electrode It can then be removed from the furnace using a gripping device.

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Claims (1)

[Claims] 1. In a multi-stage hydraulic cylinder that moves loads at various load rates and stroke lengths, One cylinder is configured as a hollow piston type cylinder (1, 2, 3), and its hollow At least one further long stroke cylinder (4) is arranged within the piston rod (3). , the hollow piston rod (3) is at the same time the cylindrical tube of the long stroke cylinder (4), Pressure medium connection ports (8, 9, 10, 11) for cylinder movement must be provided. A multi-stage hydraulic cylinder featuring: 2 The long stroke cylinder placed inside the hollow piston rod (3) is a multi-stage nested cylinder. Multi-stage hydraulic cylinder according to claim 1, characterized in that it is a cylinder (4, 6). . 3 Effective area of hollow piston type cylinder and effective area of one or more long stroke cylinders Claim 1 or 2, characterized in that the ratio to the area is from 2:1 to 50:1 at most. is the multistage hydraulic cylinder described in 2. 4. Movement of hollow piston type cylinders (1, 2, 3) and one or more long stroke series Separate pressure medium connections (8, 9, 10, 11) for the movement of the cylinders (4, 6) The multi-stage hydraulic pressure according to one of claims 1 to 3, characterized in that: Cylinder. 5. The multi-stage hydraulic cylinder according to claims 1 to 4 enables various load factors (back pressures) In the method of moving the load with different stroke lengths, the load (1 2), pressure medium is applied to the hollow piston type cylinders (1, 2, 3). and then move the load (12) with low back pressure. Load transfer, characterized in that a pressure medium acts on the stroke cylinders (4, 6) Method.