JPH0626721Y2 - accumulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an accumulator, and more particularly to an accumulator provided with a rod for detecting the position of a piston in a piston type accumulator.

[Problems to be solved in conventional technology]

Generally, the piston type accumulator is constructed as shown in FIGS. 6 and 7.

That is, in FIG. 6, one end of the cylinder 21 is screwed to close a top cover 23 having a screw hole 22 in the center, and a recess 24 is formed inside the top cover 23. 25 is movably arranged.

Then, the other end of the cylinder 21 is closed by screwing a bottom cover 27 having a hole 26 formed in the central portion thereof in the same manner as the one end, and the rod cover 28 is fitted into the screw hole 22 of the top cover 23. This rod cover 2 is screwed on
8, a rod 30 is urged by a spring 29 in a direction to be retracted into the recess 24 of the piston 25.
A magnet 31 is arranged at an end of the rod 30 located inside the rod cover 28, while a detection member 32 operated by the magnet 31 is arranged outside the rod cover 28. Is provided.

Incidentally, 33 is a seal member, and 34 is a gas valve.

Then, in the accumulator configured as described above, first, gas (generally N ₂ gas) is sealed inside the cylinder 21 between the top cover 23 and the piston 25 via the gas valve 34. On the other hand, on the other hand, a fluid such as oil flows in from the hole 26 of the bottom cover 27.

The piston 25 is displaced in the left-right direction according to the fluid pressure relative to the enclosed gas pressure,
When the pressure of the enclosed gas is appropriate, the piston 25 moves without contacting the rod 30.

Further, when the pressure of the enclosed gas becomes low, or when an excessive fluid pressure acts, the piston 25 moves leftward and comes into contact with the rod 30, and the rod 30 is pressed by the piston 25. It moves against or in accordance with the biasing force of the spring 29.

Therefore, when the rod 30 is moved by the piston 25, the magnet 3 provided at the end of the rod 30
By 1, the detection member 32 emits a signal, and it is possible to know from this signal that the piston 25 has approached the end portion on the side where the rod 30 is provided.

However, in the conventional accumulator as described above, the length of the rod 30 must be formed in consideration of the moving distance of the piston 25 when the filling pressure becomes 0. In order not to damage 30, if the distance l ₂ between the end of the rod 30 and the gas valve 34, the moving distance of the piston 25, that is, the stroke of the rod 30 is l ₁ , and the contact length of the spring 29 is x, then l ₂
> L ₁ + x must be set, and there is a problem that the entire length becomes long and the size becomes large.

As a means for solving the above problems, the one shown in FIG. 7 was devised.

Here, the same members as those shown in FIG. 6 are designated by the same reference numerals, and detailed description thereof will be omitted.
The first stage rod 35 is movable in a stepwise manner against or in accordance with a spring 29 disposed between the rod cover 28 and the rod cover 28 as shown in FIG. The eye rod 36 is adapted to move against or in accordance with the spring 37 disposed between the eye rod 36 and the first stage rod 35.

That is, when the piston 25 moves to the left due to the fluid pressure, first, first, the rod 35 of the first stage is
However, in the state where the second-stage rod 36 is not immersed therein, the rod 36 is moved to the left against the biasing force of the spring 26. Then, at the end of the movement, the second stage rod 36 moves against the biasing force of the spring 37 provided between the second stage rod 36 and the first stage rod 35.

Therefore, compared to the above, the length l ₂ of the rod cover 28 is shortened to shorten the entire length, which makes it possible to reduce the size of the entire rod cover 28. There is a problem that galling occurs between the rod 35 and the rod 36 of the second stage, the piston cannot be moved smoothly, and the rod becomes expensive.

The present invention solves the above-mentioned problems of the conventional ones, and an object thereof is to provide an accumulator which can shorten the rod cover and thereby make the whole compact.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention has a piston, one end of which is in communication with a flow path, wherein a piston having a recess on a side surface opposite to the flow path is movably disposed inside the cylinder. A rod cover provided at the other end, the rod cover communicating with the inside of the cylinder and having a rod that is urged by a spring therein and projects into the cylinder;
A detection means for detecting the movement of the rod when it moves and providing a signal is provided, gas is enclosed in the cylinder on the other end side of the piston, and the piston is brought into contact with or separated from the tip of the rod. It is possible and at the time of contact with the rod, a regulating member for regulating the rod from entering the inside of the recess is provided, and when the rod exerts a predetermined biasing force by the spring, The tip portion of the piston is configured to enter the concave portion of the piston against the restriction member.

[Action]

This invention adopts the above means, and when the piston moves against the enclosed pressure when the fluid pressure changes, a part of the moving amount of the rod is stopped by the rod when the rod stops. On the other hand, the piston moves and enters into the recess to support the piston, thereby reducing the movement amount of the rod.

〔Example〕

 An embodiment of the present invention shown in the drawings will be described below.

FIG. 1 shows an accumulator according to the present invention, in which a top cover 3 having a screw hole 2 at its center is screwed to one end of a cylinder 1 to close it.
A recess 4 is formed inside the cylinder 1 on the side of the top cover 3 and projects into the recess 4.
In addition, a pair of leaf springs 15, 15 that are restricting members and are spaced apart from each other at a distance narrower than the diameter of a rod to be described later are provided movably with the piston 5 fixed with screws 16, 16. .

Then, the other end of the cylinder 1 is screwed and closed by a bottom cover 7 having a hole 6 formed in the central portion similarly to the one end, and the rod cover 8 is attached to the screw hole 2 of the top cover 3.
The rod cover 8 of the rod 10 is screwed into the rod cover 8 and the rod 10 is urged by the spring 9 in the direction in which the rod 5 is retracted into the recess 4 of the piston 5. A magnet 11 is arranged at an end portion located inside the magnet, while a detection member 1 operated by the magnet 11 is provided outside the rod cover 8.
2 are provided.

In addition, 13 is a seal member and 14 is a gas valve.

Next, the operation of the above will be described.

First, gas (generally N ₂ gas) is sealed inside the cylinder 1 between the top cover 3 and the piston 5 through the gas valve 14, while the oil is filled in the hole 6 of the bottom cover 7. A fluid such as the above flows in. And
With respect to the enclosed gas pressure, the piston 5 is configured to be displaced in the left-right direction according to the magnitude of the fluid pressure introduced into the cylinder 1 through the hole 6, and the enclosed gas pressure is At a proper time, the piston 5 is displaced without coming into contact with the rod 10.

Further, when the pressure of the enclosed gas becomes low, or when the excessive fluid pressure acts to move the piston 5 to the left, the leaf spring 1 is larger than the diameter of the rod 10.
The distance between 5, 15 is narrower, and both leaf springs 15, 15
By the fact that the force compressing said spring 9 is less than the force required to insert rod 10 in between,
While compressing the spring 9, the rod 10 moves the piston 5
Move to the left with.

Therefore, when the rod 10 is moved by the piston 5, the magnet 11 provided at the end of the rod 10 is moved.
Thus, the detection member 12 emits a signal, and this signal makes it possible to know that the piston 5 has approached the end on the rod 10 side.

Then, after the spring 9 is compressed and brought into close contact, the rod 10 is allowed to move into the recess 4 through the space between the leaf springs 15, 15 to allow the piston 5 to move to the left. It will be.

Therefore, since the concave portion 4 of the piston 5 bears a part of the movement of the conventional rod, the moving distance of the rod 10 can be shortened, and therefore the length of the rod cover 8 can be shortened. is there.

That is, the distance l between the end of the rod 10 and the gas valve 14
₂ , the moving distance of the piston 5, that is, the rod 10
Stroke is l ₁ , the contact length of spring 9 is x, piston 5
If the depth of the concave portion 4 is l ₃ , then l ₂ > l ₁ + x−l ₃
Therefore, the required length of the rod cover can be shortened.

FIGS. 4 and 5 show the accumulator according to the present invention and the one used in another embodiment. The other members are the same as those in the above-mentioned embodiment, so the description thereof will be omitted. In this case, while the leaf springs 15 and 15 were used as the restricting members in the above-described embodiment, the rubber sheet 19 having the hole 18 provided with the slit 17 in the four directions at the center was used. The recessed portion 4 of the piston 5 is covered with the seat 19, and even in the case of such a configuration, the spring 9 is compressed and contracted at the initial stage of the movement of the piston 5, so that the rod 10 is integrally formed. Move, spring 9
If the maximum biasing force acts due to the shrinkage of the piston 5, the rod 10 then enters the inside of the rubber sheet 19 to allow the piston 5 to move, which is the same as in the above embodiment. Similarly, the length of the rod cover can be shortened.

[Effect of device]

As described above, according to this invention, the piston is provided with the concave portion, and the piston is provided with the regulating member for regulating the entry of the rod into the concave portion. Since the rod is responsible for approaching the piston, the moving distance of the rod can be shortened, and the length of the rod cover can be shortened and the overall size can be reduced. Is to have.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an accumulator according to the present invention, FIGS. 2 and 3 show a piston and a leaf spring used in the one shown in FIG. 1, FIG. 2 is a side view, and FIG. Longitudinal sectional views, FIGS. 4 and 5 show other parts of a piston and a leaf spring, FIG. 4 is a side view, FIG. 5 is a longitudinal sectional view, and FIGS. 6 and 7 show conventional accumulators. FIG. 1, 21 ... Cylinder 2, 22 ... Screw hole, 6, 18, 26 ... Hole 3, 23 ... Top cover 4, 24 ... Recess 5,25 ... Piston 7, 27 ... Bottom cover 8, 28 ... Rod cover 9, 29, 37 ... Spring 10, 30, 35, 36 ... Rod 11, 31 ... Magnet 12, 32 ... Detection member 13, 33 ... Seal member 14, 34 ... Gas valve 15 ...... Leaf spring 16 …… Screw 17 …… Slit 19 …… Rubber sheet l ₁ …… Rod stroke l ₂ …… Distance between rod and gas valve l ₃ …… Piston recess 4 depth x …… Spring Adhesion length

Claims (1)

[Scope of utility model registration request] 1. A piston (5) having a recess (4) formed on a side surface opposite to the flow path is movably disposed inside a cylinder (1) having one end communicating with the flow path, The other end of the cylinder (1) is communicated with the inside of the cylinder (1) and is urged by a spring (9) inside the cylinder (1).
A rod cover (8) having a rod (10) protruding inward, and a detection means (12) provided on the rod cover (8) for detecting the movement of the rod (10) and issuing a signal. Gas is enclosed in the cylinder (1) on the other end side of the piston (5) so that the piston (5) can come into contact with and separate from the tip end portion of the rod (10), A restricting member (15, 19) for restricting the rod (10) from entering the inside of the recess (4) at the time of contact with the rod (10) is arranged,
0) is such that, when a predetermined biasing force is applied by the spring (9), the tip portion of the spring (9) enters the recess (4) of the piston (5) against the restriction members (15, 19). Accumulator characterized by.