JPH0570724B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention uses bellows to efficiently perform seal-like expansion and contraction movements such as shaft movement and pipe movement, thereby smoothly and safely. This invention relates to a moving mechanism for moving.

(Prior art) A seal-like moving mechanism using a conventional bellows is
Bellows tubes were arranged in series to absorb the amount of expansion and contraction movement. As a result, inclusions tend to get into the bellows portion, and it is difficult to make the expansion and contraction movement work uniformly.In particular, large expansion and contraction movements require an extremely large space in the axial direction, which is a serious drawback. These make the telescopic movement and sealing condition unreliable over long periods of use.

In addition, although there is an axial movement mechanism in which multiple bellows pipes are simply arranged multiplexed at the same position and connected sequentially, in the bellows processing process of bellows pipes with different large and small diameters, the difference between the pipe wall thickness before processing and the bellows portion after processing is known. If the height and pitch of the peaks are the same, then the processing average wall thickness = wall thickness (bellows valley diameter/bellows average diameter) ^0.5 , i.e. tp = t (dr/dp) ^0.5 , calculate the wall thickness reduction due to processing of the pipe wall thickness. Therefore, the wall thickness of the bellows becomes thinner as the aperture becomes smaller, and becomes thicker as the aperture becomes larger, as tp ₁ < tp ₂ < tp ₃ . In this case, a load with an equal amount of movement corresponding to the resistance constant of the inner and outer bellows tubes is not applied, so smooth axial movement between each bellows tube cannot be obtained, and there is a problem that some bellows tubes are easily fatigued. .

Here, the resistance constant indicates the elastic force generated per unit length when the bellows is subjected to expansion and contraction.

(Problems to be Solved by the Invention) This invention aims to efficiently and reliably increase the telescopic movement in a seal-like moving mechanism using bellows of the same length. Rather, the problem in the prior art is solved by connecting the bellows in a multiple nested manner and by making the loads on the inner and outer bellows work in accordance with each resistance constant.

(Means for Solving the Problems) In order to achieve the above object, the present invention arranges bellows pipes having different diameters in a multiple nested manner by inserting connecting pipes between them, and the innermost and the outermost bellows pipes are arranged in a multiple nested manner. In a moving mechanism in which the moving end of each bellows pipe other than the opposing outer end of the outer bellows pipe is sequentially connected to a connecting end, bellows of the same height and pitch have different diameters. Due to the difference in the resistance constant due to the difference in wall thickness of the bellows part due to the aforementioned processing thickness reduction of the plurality of bellows pipes, the resistance constant of the bellows with respect to the amount of movement increases sequentially from the small diameter bellows pipe to the large diameter bellows pipe. Furthermore, a movement mechanism using multiple seal bellows is provided, which is characterized in that the movement amount of the load from the small diameter to the large diameter is shifted in one direction so that the amount of movement to be applied becomes smaller sequentially in accordance with the resistance constant of each. A movable wall that variably divides the cylinder chamber is fixed to the tip of a movable shaft inserted into the cylinder, and a fixed wall fixed to the cylinder mouth supports the movable shaft so that it can move forward and backward in the axial direction. The multiple bellows are inserted into the movable shaft in the cylinder chamber, and the opposing outer ends of the innermost and outermost bellows tubes are fixed to the movable wall and the fixed wall located toward each outer end, respectively. Then, pressure is applied alternately to the cylinder chamber, which is variably partitioned by a moving wall, to move the moving shaft forward and backward.
Alternatively, we propose a moving mechanism using multiple seal bellows, which is characterized by moving the moving shaft forward and backward in a sealed state by applying an external force to the moving shaft.

(Function) The inner and outer bellows pipes connected in a staggered manner expand and contract in the same direction via the connecting pipes,
A large amount of movement can be obtained.

By arranging and connecting bellows tubes inserted in a nested manner so that the amount of movement applied from the small diameter to the large diameter becomes smaller in sequence according to the resistance constant of each bellows tube, the load caused by external force can be reduced. can be made to extend in proportion to the resistance constant of each bellows tube whose moving resistance constant increases successively from the small diameter to the large diameter, so the resistance constant of each bellows tube can be fully utilized, and each other's resistance constant is Since the load is evenly absorbed in the polymerization region, there is no possibility that an unnecessarily large moving force will be applied to only some of the bellows pipes.

The moving and fixed walls of the multiple bellows apply a moving load commensurate with the resistance constant of each bellows tube,
It acts as a stable moving stress on the whole and smoothly changes the two chambers.

(Example) Next, a specific example of a moving mechanism using multiple seal bellows according to the present invention will be described with reference to the drawings.

FIG. 1 is a partially cutaway side view of a multiple bellows of a moving mechanism for carrying out the present invention. 1 is a multiple seal bellows, and three bellows parts having the same height and pitch and different diameters and resistance constants are shown in FIG. The bellows pipes 2, 3, and 4 are inserted into each other in a nested manner multiple times by inserting the connecting pipes 6 and 7, and the amount of movement of the bellows pipes 2, 3, and 4 is loaded from the small diameter side to the large diameter side. Each bellows tube 2, other than the mutually opposing outer ends 2a and 4a of the innermost bellows tube 2 and the outermost bellows tube 4, is regulated by shifting in one direction so as to be gradually smaller in accordance with the respective resistance constants. The movable plates 5, 5 are fixedly interposed to the movable ends 2b, 3a, 3b, 4b of the connecting pipes 6, 7, and the ends 6a, 6b,
7a and 7b are successively connected to each other alternately. Fig. 2 is a partially cutaway side view of the main part of the cylinder showing an axis movement mechanism using multiple bellows that embodies the present invention, and Fig. 3 is a partially cutaway side view of the same cylinder after the axis has moved. Supply/discharge ports 16, 17 and 1 respectively
A movable wall 10 is attached to the tip of a movable shaft 13 inserted into a bottomed cylinder 8 with a blind lid 9.
is fixed 10a, and the moving shaft 1 in this cylinder 8 is fixed.
3, three bellows tubes 2, 3, 4, floating plate 5,
5. Insert the multi-sealed bellows pipe 1 formed by connecting the connecting pipes 6 and 7 to form the innermost bellows pipe 2.
The outer end 2a of the outermost bellows tube 4 is firmly sealed to the movable wall 10, and the outer end 4a of the outermost bellows tube 4 is firmly sealed to the fixed wall 11 fixed to the mouth 8a of the cylinder 8, so that the movable shaft 13 is fixed to the bearing part. The interior of the cylinder 8 is divided into two variable chambers A and B by a movable wall 10. 15 is an O mounted on the periphery of the moving wall 10.
The ring ensures airtightness with the inner wall surface of the cylinder 8. 20, 21, 22, 23 are sheath tubes, and the movable wall 1
0 and the fixed wall 11 to guide the movement of the floating plates 5, 5 of each bellows pipe 2, 3, 4, and to restrict eccentric movement of the floating plates 5 during movement, thereby ensuring smooth operation. , has the effect of promoting light movement, and has projections 20 on the inner ends of some of the sheath tubes 20 and 22.
By providing a, 22a, the bellows pipe 3,
This is effective in preventing overwork of the bellows pipes 2, 3, and 4 by preventing the floating plates 5, 5 of No. 4 from extending and moving more than necessary.

FIG. 4 is an enlarged vertical sectional view of the main part of the cylinder showing another embodiment. In this moving mechanism, the cylinder 8
The chamber B is not provided with a supply/discharge port, and the retracting movement of the advanced moving shaft 13 is performed in a sealed manner by an external load applied to the moving shaft 13.

The moving mechanism according to the present invention is such that each bellows pipe 2, 3, 4 expands and contracts by dividing the pressure applied to the entire body by a multi-seal bellows 1 according to their respective resistance constants. When forming a thick bellows material pipe into a bellows pipe, the wall thickness of the bellows will be uniformly reduced due to processing, but if the depth and pitch of the peaks in the bellows cross section are the same, the diameter will be smaller. As you can see, the thickness reduction of the bellows increases gradually, and the resistance constant against the amount of movement decreases. Using this principle, the largest amount of divided movement is applied to the innermost bellows tube with the smallest diameter, and each bellows tube 2, 3, and 4 is divided by the resistance constant so that the amount of divided movement becomes smaller as the diameter increases. By sequentially regulating and arranging the bellows tubes, a load corresponding to the amount of movement corresponding to the resistance constant of each bellows tube 2, 3, and 4 is applied, so that the load is absorbed in the transition area where the resistance constant of each bellows tube overlaps with each other. In addition, smooth movement without steps can be obtained, and the bellows tube is effective in that it can withstand long-term use without easily cracking during expansion and contraction movement.

Based on this configuration, the operation of the moving mechanism of the present invention will be explained with reference to FIGS. 2 and 3.
Connecting pipes 6 and 7 are connected in a staggered manner in order to regulate the amount of _load movement of _{X 1 ,} By supplying gas, the valve of the outlet 19 of the chamber B on the fixed wall 11 side is opened, and each bellows pipe 2, 3, 4 is contracted, and the movable wall 10 is moved to the fixed wall 11.
By moving the entire load movement amount Y to the side, the bearing part 14
The moving shaft 13 supported by the moving shaft 13 is pushed outward, and the moving force of the moving shaft 13 is used to function as a predetermined action, and then the discharge port 19 of the chamber B on the fixed wall 11 side
The moving wall 10 is pushed back by supplying high pressure gas from the supply port 18 and opening the valve of the discharge port 17 on the blind lid 9 side.
The load transfer amounts X ₁ , X ₂ , and X ₃ of No. 3 and 4 are expanded and returned to normal. By sequentially repeating this expansion and contraction movement and moving the moving shaft 13 forward and backward, a predetermined action is achieved.

Although the above description has been made as one embodiment of the present invention, by using the moving mechanism using the multi-seal bellows 1 as a seal bellows for expansion joint pipes, valves, etc., desired effects can be achieved.

(Effects of the Invention) The present invention sequentially inserts and arranges a plurality of bellows pipes having different diameters in a nested manner so that the resistance constant of the bellows with respect to the amount of movement increases from a small diameter bellows pipe to a large diameter bellows pipe. The bellows pipes are arranged so that they are shifted in one direction so that the amount of movement applied to them gradually decreases from the small diameter to the large diameter according to the resistance constant of each bellows pipe, and the bellows is placed at the end of the connecting pipe inserted between the bellows pipes. It is characterized by a moving mechanism using multiple seal bellows, which are formed by alternately connecting the movable end portions of tubes, and each division is The amount of movement is utilized in space and combined three-dimensionally so that the movement force is evenly distributed in the same state.

Therefore, it is easy to greatly amplify the amount of movement by each bellows tube in a small three-dimensional space, and it is easy to make this type of seal-like movement mechanism short and compact without consuming a large space in the length direction. becomes.

In particular, by connecting the bellows tubes with their displacements shifted in the same direction according to their respective resistance constants, the load due to external force is applied to each bellows tube so that the displacement decreases from the small diameter to the large diameter. Since the resistance constant of each bellows tube is fully utilized in accordance with the resistance constant of Smooth movement with no steps can be obtained, and there is no risk of excessive movement force being applied to only a part of the bellows pipe, making it durable. Also, during movement, strict sealing performance and stable and smooth movement can be achieved throughout the pipe. It has the ability to expand and contract, and is durable enough to maintain its effectiveness even after long periods of use.

[Brief explanation of the drawing]

FIG. 1 is a partially cut-away side view of a multiple seal bellows showing a moving mechanism for carrying out the present invention, and FIG. 2 is a partially cut-away side view of a main part showing a shaft moving mechanism using the multiple seal bellows of this invention. 3 is a partially cutaway side view after the shaft has been moved, and FIG. 4 is an enlarged vertical cross-sectional view of the main parts of the shaft moving mechanism showing another embodiment. In the figure, 1 is a multi-seal bellows, 2, 3, 4 are bellows tubes, 2a, 4a are outer ends, 2b, 3a,
3b, 4b are moving ends, 5 is a floating plate, 6, 7 are connecting pipes, 6a, 6b, 7a, 7b are ends, 8 is a cylinder, 8a is a mouth part, 10 is a moving wall, 10a is a fixed part, 11 is a fixed wall, 12 is a fixed portion, 13 is a moving shaft, 14 is a bearing portion, 20, 21, 22, 23 are sheath tubes, 20a, 22a are protrusions, and A, B are cylinder chambers.

Claims (1)

[Scope of Claims] 1. A plurality of bellows pipes having different diameters are inserted and arranged in multiples with connecting pipes interposed between them, and each of the bellows pipes other than the opposing outer ends of the innermost and outermost bellows pipes is In a moving mechanism in which moving ends of bellows pipes are connected to connecting ends in turn, the bellows resistance constant with respect to the amount of movement is made to increase sequentially from small diameter bellows pipes to large diameter bellows pipes. A moving mechanism using multiple seal bellows, characterized in that the bellows are shifted in one direction so that the amount of movement applied to the diameter becomes smaller in sequence in accordance with the respective resistance constants. 2. The moving mechanism using a multi-seal bellows according to claim 1, wherein the bellows pipe is connected to the connecting pipe end with a floating plate fixedly interposed at each moving end. 3. The moving mechanism using multiple seal bellows according to claim 2, wherein the floating plate is guided by a sheath tube to restrict eccentric movement. 4. The movement mechanism using a multi-seal bellows according to claim 3, wherein the sheath tube is provided with a protrusion at the inner end on the outer end side of the smallest diameter bellows tube to limit extension of the bellows tube. 5 A movable wall is fixed to the tip of the movable shaft inserted into the cylinder, and a cylinder chamber is variably divided by being supported by a fixed wall fixed to the cylinder mouth, and the movable wall is fixed to the movable shaft inside the cylinder. A plurality of bellows pipes with different diameters are arranged such that the resistance constant of the bellows increases sequentially from a small diameter bellows pipe to a large diameter bellows pipe, and are inserted and arranged in multiples with connecting pipes interposed between them. The opposing outer ends of the innermost and outermost bellows tubes are connected to a moving wall and a fixed wall, so that the amount of movement applied to the pipes decreases from the small diameter to the large diameter in order according to the respective resistance constants. A moving mechanism using a multi-seal bellows, in which the moving ends of the other bellows pipes are alternately connected to the ends of the connecting pipes. 6. The moving mechanism using a multi-seal bellows according to claim 5, wherein the bellows pipe is connected to the connecting pipe end with a floating plate fixedly interposed at each moving end. 7. The moving mechanism using multiple seal bellows according to claim 6, wherein the movable wall and the fixed wall are arranged so that eccentric movement is restricted by guiding each movable plate by a sheath tube provided inside in the direction of movement. 8. The movement mechanism using multiple seal bellows according to claim 7, wherein the sheath tube is provided with a protrusion at each inner end on the outer end side of the smallest diameter bellows tube to limit extension of the bellows tube. .