JPS621708Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pneumatic operating device for vacuum shields and disconnectors. More specifically, in addition to improving the closing characteristics of a pneumatic operation device for a windshield cutter that uses double pistons of large and small sizes, the closing and cutting operations are performed using compressed air and a spring. It has improved shearing characteristics during shearing.

In the double piston type air operating device,
Since the internal piston provided on the operating rod, which has a movable contact at the tip, maintains contact between the fixed contact and the movable contact via a closing spring supported within the hollow external piston, in the unlikely event that the external piston part Even if the closing spring slightly moves in the cutting direction due to a drop in the compressed air pressure for closing and holding, the fixed contact and the movable contact can maintain proper contact with each other by the closing spring. However, in this double piston system, the outer piston mechanically collides directly with the shoulder of the inner piston to open the pole, so the piston needs to have great mechanical strength. Ta. Further, there was a drawback that operation noises were generated when the piston portion collided with each other.

In order to improve these drawbacks, the present applicant previously proposed an air operating device having the structure shown in FIG.
Referring to the figure, reference numeral 1 denotes an operating rod connected to a movable contact (not shown) of a vacuum valve in a vacuum shield and disconnector, and the operating rod 1 is inserted into a cylinder 2 so as to be vertically movable. The operating rod 1 is integrally provided with a piston portion 3, and the piston portion 3 slides via a seal member 7 against the wall surface of a hollow chamber 6 of the operating piston 5 housed in the chamber of the cylinder 2. It is freely configured.

The hollow chamber 6 forms a so-called cylinder chamber, and the operating rod 1 having the piston portion 3 is inserted into the hollow chamber 6. A spring 8 is mounted between the piston portion 3 and the lower surface of the hollow chamber 6 to constantly bias the operating rod 1 in the closing direction. 2
Reference numeral 2 designates a seat for the spring 8, which is screwed and fixed to the operating piston 5 and slidably fitted into the lower part 1' of the operating rod 1. A check valve 2 is installed on the catch seat 22.
A communication hole 21 having a diameter of 0 is provided.

Furthermore, after the movable contact connected to the operating rod 1 comes into contact with the fixed contact of the switch and the piston portion 3 stops moving, the operating piston 5 further moves.
A hollow portion 6a is formed between the operating piston 5 and the upper head portion 9. Further, the upper head portion 9 is provided with a communication hole 11 that communicates the hollow portion 6a formed between the piston portion 3 and the upper head portion 9 with the cylinder chamber 4.
A piston portion 12 configured to be slidable on the inner wall surface of the cylinder chamber 4 is provided at a proper location of the operating piston 5. Further, between the piston portion 12 and the upper surface of the cylinder 2, the operating piston A wedge spring 13 is loaded to constantly bias the spring 5 downward. Reference numeral 14 denotes a compressed air supply port, which supplies compressed air into the lower hollow chamber 4a of the cylinder chamber 4 to raise the operation piston 5 for a closing operation, and is connected to an air pump (not shown).

Reference numeral 15 denotes an exhaust valve that opens and closes the exhaust passage 16, and the exhaust valve 15 is connected via a rod 27 to a piston 29 provided in a cylinder chamber 28. 30 is a spring wound around the rod 27, and 31 is a pipe connected to the cylinder chamber 28. And piping 31
By supplying compressed air to the cylinder chamber 28 and moving the exhaust valve 15 to the left in FIG. 1 against the spring 30 to open the exhaust passage 16, the cylinder chamber 4
The compressed air in the lower hollow chamber 4a of the exhaust port 17
It is then exhausted.

Note that 18 is a buffer member in which a piston member 18b is lifted up by a spring 32 within the cylinder portion 18a. Then, when the operating rod 1 at the time of a breakage is lowered, the lower portion 1' of the rod hits the piston member 18b and a buffering effect is exerted. 19
is a communication hole that communicates the cylinder chamber 4 with the atmosphere.

Next, in the double piston type air operating device, the operating piston 5 is raised by compressed air from the supply port 14 while accumulating force in the blade spring 13 to perform a closing operation. At this time, the piston part 3
is pushed up by the spring 8, so the operating rod 1 is also lifted up following the operating piston 5, and
At this time, the charging operation is performed while sucking air from the cylinder chamber 4 into the hollow portion 6a through the communication hole 11. In other words, when the injection is completed, the first
As shown in the figure, a suitable amount of hollow section 6a is formed between the piston chamber 3 and the upper head section 9 of the operating rod 1.

In this way, after the movable contact comes into contact with the fixed contact and the piston part 3 stops moving, only the operating piston 5 is further overrun to form the hollow part 6a, so that in the unlikely event that the cylinder chamber 4 Even if the pressure of the compressed air in the lower hollow chamber 4a decreases and the operating piston 5 moves slightly downward, the movable contact integrated with the operating rod 1 is kept in pressure contact with the fixed contact by the elastic force of the spring 8. Since the hollow portion 6a exists, the pressure contact force of the contact portion can be maintained and a stable closing state can be maintained.

On the other hand, when the cooling is interrupted, compressed air passes from the arrangement 31 to the cylinder chamber 28, and the piston 29 and rod 2
7, the exhaust valve 15 is moved to the left in FIG.
7, the operating piston 5 is first lowered by the elastic force of the break spring 13, and the upper head portion 9 comes into contact with the piston portion 3. At this time, the hollow part 6a
The volume of the compressed air is reduced and the compressed air is exhausted from the communication hole 11 to the cylinder chamber 4. And the communication hole 11
By setting the cross-sectional area to an appropriate size, the upper head portion 9 will not suddenly collide with the piston portion 3 when the sheath cutting operation starts, and the piston 3 and the operating rod 1 will not be damaged. There is an advantage that there is no

However, the above configuration has the following problems.
That is, at the time of insertion, the piston part 3 of the operating rod 1 is pressed by the spring 8 and is in contact with the upper head part 9, and the operating piston 5 and the operating rod rise almost together, and after the contact touch, the piston part 3 stops rising, and only the operating piston 5 rises to form the hollow portion 6a. At this time, the air flowing into the hollow part 6a is limited by the size of the cross-sectional area of the communication hole 11, so the inside of the hollow part 6a becomes negative pressure, and the stopped piston part 3 is pulled by the operating piston 5 and moves further. As a result, the following problems occur. That is, the pressing force due to large air pressure acting on the operating piston 5 acts on the contact portion after the contact is touched, and the contact portion may be damaged or
Alternatively, there is a risk that the heated contact portions may be welded. For this reason, after the contact touch, the negative pressure in the hollow part 6a is quickly released and the piston part 3
It is necessary that the operating piston 5 does not move along with the operating piston 5.

The present invention solves the above problems, and the embodiment shown in FIG. 2 will be described below.

In the present invention, as shown in the figure, a small-diameter communication hole 11 is provided in the upper head portion 9 of the operating piston 5, as in the conventional case, and a communication hole 11 with a larger diameter than the communication hole 11 is provided in another position, and in the opposite direction. A communication hole 24 having a stop valve 23 is provided. The check valve 23 opens when the operating piston 5 further rises after the piston portion 3 stops rising due to the contact touch, allowing air to smoothly flow from the cylinder chamber 4 into the hollow portion 6a. In other words, the hollow portion 6a has not only the small diameter communication hole 11 but also the large diameter communication hole 24.
Since a large amount of air also flows in from the hollow portion 6a, the pressure in the hollow portion 6a does not become negative as in the case shown in FIG. Note that 25 is a ball valve, and 26 is a seat having a ventilation hole. According to this embodiment, when the shrinkage is interrupted, the operating rod 5 is lowered and the check valve 2 is
5 is closed, the volume of the hollow part 6 is reduced.
The compressed air inside a escapes only through the communication hole 11. As a result, during a power outage, the upper head portion 9 does not collide with the piston portion 3 of the operating rod 1, as in the conventional case, and there is no risk of damage to the piston portion 3 or the upper head portion 9. On the other hand, when only the operating piston 5 rises after the piston part 3 is stopped by the contact touch during closing, the check valve 25 opens as described above and air smoothly flows into the hollow part 6a. Operation piston 5 and break spring 1
Return to the input position while accumulating power of 3.

According to the present invention, there are the following effects.

When the cylinder is cut off, the compressed air in the hollow part 6a formed between the upper head part and the piston part is gradually discharged into the cylinder chamber 4 through the small diameter communication hole, so that the upper head part collides with the piston part. There is no risk of damage to the piston section or the upper head section. As a result, a material with weak strength can be used as the piston member, so instead of steel, it can be replaced with aluminum or the like, and a thinner material can be used, making the structure more compact. It can also eliminate impact noise. On the other hand, after the contact is touched at the time of closing, the check valve 23 automatically opens and a large amount of air flows into the hollow part 6a in a short time, so that the piston part 3, which has stopped moving at a predetermined position, is transferred to the operating piston 5. Therefore, there is no further tension, and therefore, it is possible to eliminate the possibility that a strong pressing force will be applied to the fixed contact and the movable contact after the contact is touched, and the contact portion will be damaged or welded.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional example of a double piston type air operating device, and FIG. 2 is a sectional view of an air operating device according to the present invention. 1...Operating rod, 2...Cylinder, 3...
Piston part, 4... Cylinder chamber, 5... Operation piston, 6... Hollow chamber, 6a... Hollow part, 8...
Spring, 9... Upper piston part, 10... Empty part,
11...Communication hole, 13...Shipping spring, 23...
Check valve, 24...communication hole.

Claims (1)

[Claims for Utility Model Registration] An operating rod 1 connected to a movable contact of a switch is movably provided in a cylinder 2 having a cylinder chamber 4, and a piston portion 3 provided on the operating rod 1.
is slidably provided in the hollow chamber 6 of the operation piston 5 installed in the cylinder chamber 4, and
A spring 8 for biasing the operating rod 1 in the closing direction is provided between the spring seat 22 provided at the end of the operating piston 5 and the piston portion 3, and the operating piston 5 is After the movable contact comes into contact with the fixed contact of the switch and the piston part 3 stops moving, the operation piston 5 further moves and the upper A hollow part 6a is formed between the head part 9 and the piston part 3, and passes through the upper head part 9 of the operating piston 5, so that a hollow part 6a is formed between the upper head part 9 and the operating piston 5. In the pneumatic operating device for a cylinder disconnector, which is provided with a small-diameter communication hole 11 that communicates the formed hollow part 6a with the cylinder chamber 4, the communication hole 24, which has a larger diameter than the communication hole 11, is provided in the upper head part. 9, and the communication hole 24 is provided with a check valve 23 so that the communication hole 24 is closed by the air pressure flowing from the hollow part 6a to the cylinder chamber 4. Operating device.