JPS6132221Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water pressure control valve in which valve bodies are combined in multiple stages.

The valve body combination of the water pressure control valve includes:
There are three types: 1-tier, 2-tier, and 3-tier. 20-40
In the case of a low pressure circuit of Kg/cm ² , there is no particular problem with a single-stage valve, but in the case of a 70Kg/cm ² pressure circuit such as the drive circuit of a hydraulic press.
In the case of a high-pressure circuit exceeding 1, the valve body receives high liquid pressure from the liquid inlet side when the valve is closed, and a 1-stage valve requires a large external force when opening the valve, so a 2-stage valve,
A three-stage valve is used. FIG. 1 schematically shows the structure of this type of water pressure control valve as a two-stage valve.

Inside the box 5, two communicating upper and lower liquid chambers 8 and 10 are provided, with a liquid inlet port 9 opening in the upper liquid chamber 8 and a liquid outlet port 11 opening in the lower liquid chamber 10, respectively. A second-stage valve body 12 from the upper liquid chamber 8 is fitted into the orifice 13, and a first-stage valve body 15 is assembled therein. 1st stage valve body 1
The spindle 4 fixed to the box 5 is pushed downward by a spring 38 in the case 37 at the upper part of the box 5, and is connected to a two-stage lifting cylinder 39 at the lower part of the box 5.

The valve is closed by lowering the lifting cylinder 39 and lowering the valve bodies 12, 15 to the lower limit positions shown in the figure.

When opening the valve, first, the lifting cylinder 39 is operated in the first stage, and the first stage valve body 1 is opened.
Slightly increase 5. As mentioned above, in high-pressure circuits such as hydraulic press drive circuits, when the valve is closed, the valve body receives a large force in the closing direction from the liquid from the liquid inlet port 9, and a large external force is required to open the valve. As a general rule, in the case of this valve, the diameter of the first stage valve body 15 is small and the pressure it receives is not so great, so the first stage valve body 15 can be pushed up with a relatively small force. .

When the first stage valve body 15 is lifted up, the lifting cylinder 39 is caused to perform the second stage operation, and the second stage valve body 12 is pushed up together with the first stage valve body 15 to open the liquid inlet port. The liquid from 9 is routed through orifice 13 to liquid outlet port 11. In this case, when the first stage valve body 15 rises, the upper and lower liquid chambers 8 and 10 communicate with each other, and the difference in hydraulic pressure between the upper and lower liquid chambers 8 and 10 becomes small or disappears. A large force is no longer required when pushing up the valve, and the external force when opening the valve can be kept small as a whole. This is the operating principle of two-stage and three-stage water pressure control valves.

However, in reality, the second stage valve body 12 is tightly and watertightly fitted to the valve seat 6 (see Fig. 2).
The force required to push it up is not small. for example,
In the case of a drive circuit for a hydraulic press used to manufacture punched pipes, it takes 600~
It is said to require a force of 800 kg. If such a large force is required, in the conventional valve body push-up method, when pushing up the valve body, the portion of the spindle 4 below the valve body may be deformed, and buckling breakage may occur in this portion.

In addition, this type of water pressure control valve relies only on the spring 38 to provide a holding force in the valve closing direction when the valve is opened, so if the hydraulic pressure balance between the upper and lower liquid chambers 8 and 10 is disrupted, Even if the lifting cylinder 39 performs a downward movement, the valve bodies 12,1
5 may not lower, and in extreme cases the valve bodies 12, 15 may even rise.

This invention solves all of the above problems by changing the valve body from the conventional push-up method to a pull-up method, and also reduces the number of spindle shaft seals by half from the conventional two to one, resulting in a larger structure. The present invention provides a multi-stage water pressure control valve whose width is simplified.

Hereinafter, the valve of the present invention will be explained in detail based on the embodiment shown in FIG.

This water pressure control valve consists of a valve part 1 and a cylinder part 2 above the valve part 1, which are connected by a connecting tube 3, and one spindle 4 passes through the center part. This spindle 4 is also the spindle rod of the cylinder part 2. Note that the valve section 1 and the cylinder section 2 are shown disassembled in the drawings due to space limitations.

Starting from the valve section 1, a valve seat 6 is inserted into a box 5 whose bottom is closed, leaving a space at the bottom, and the connecting tube 3 is screwed above it through a shaft sealing section 7. The space around the valve seat 6 is an upper liquid section 8 and has a liquid inlet port 9, and the space below is a lower liquid chamber 10 and has a liquid outlet port 11.

A second stage valve body 12 is inserted into the inside of the valve seat 6 in a watertight manner and movable up and down, and its lower end is fitted into the orifice 13 at the lower limit position. 2nd stage valve body 1
2 is provided with one orifice 14, and the first stage valve body 15 combined with the second stage valve body 12 fits into this orifice 14 at its lower end at the lower limit position.
This first stage valve body 15 is fixed to the lower end of the spindle 4 from below.

Reference numeral 16 designates a locking nut for the first stage valve body 15, which is screwed into the second stage valve body 12 from above with a slight gap G between it and the valve body 15.

The upper liquid chamber 8 and the internal space 8' of the valve seat 6 are always in communication through the through hole 17, and this internal space 8'
The through hole 18 provided in the locking nut 16 also provides constant communication between the valve body 12 and the internal space of the second stage valve body 12 .
The upper liquid chamber 8 and the lower liquid chamber 10 are directly connected through a through hole 19 provided in the valve seat 6 when the second stage valve body 12 is raised.

The shaft sealing portion 7 is fitted into the piston nut 20 from below with a packing adapter 21 and a packing 2.
2. It has a structure in which the bushes 23 are stacked one on top of the other in order and a nut 24 is screwed in from above.

The packing 22 is also interposed between the shaft seal 7 and the valve seat 6, and between the valve seat 6 and the box 5, in addition to the shaft seal 7.

Next, the cylinder part 2 will be described. The cylinder tube 25 has a lower part sealed with water by the connecting tube 3, has a second piston 27 and a spindle 4 inside, and has an upper part connected to the piston nut 4.
It has a water-tight structure due to zero.

The first piston 26 is provided below the second piston 27 and is movable relative to the second piston 27 . Above and below the first piston 26 are oil chambers 28,
29, and the oil chambers 28, 29 are provided with oil inlet/outlet ports 30, 31. The stroke S ₁ of the first piston 26 corresponds to the first stage valve body 1 in the valve section 1.
5 and the locking nut 16.

The second piston 27 is fixed to the spindle 4, the cylinder tube 25, and the first piston 26
and is movable relative to the piston nut 40. Between the second piston 27 and the piston nut 40 is an upper oil chamber 3 provided with an oil inlet/outlet port 33.
2 is provided, and the lower oil chamber is also used as the upper oil chamber 28 of the first piston 26. It is assumed that the stroke S ₂ of the second piston 27 is the sum of the vertical movement amount of the second-stage valve body 12 in the valve portion 1 and the gap amount G.

34 and 35 connect the second piston 27 to the spindle 4
tube and lock nut for fastening to the
36 is Patsukin.

To explain the operation of the water pressure control valve with the above configuration, the valve is closed by the cylinder part 2.
At this time, oil is supplied to the upper oil chamber 32 of the second piston 27 from the oil inlet/outlet port 33, and the second piston 2
7 to the lower limit position shown in the figure.

That is, when the second piston 27 descends to the lower limit position, the first stage valve body 15 at the lower end of the spindle 4 fixed to the second piston 27 moves to the second stage valve body 1.
2 to the lower limit position, and orifices 13 and 14
The upper and lower liquid chambers 8 and 10 are completely separated.

To open the valve, first open the cylinder part 2.
, oil is put into the lower oil chamber 29 of the first piston 26 from the oil inlet/outlet port 31, and the first piston 26
Increase S ₁ .

This rise of the first piston 26 causes the second piston 27 to rise by S ₁ , and pulls up the first stage valve body 15 at the lower end of the spindle 4 fixed to the second piston 27 (S ₁ ≈G ₁ ). As a result, the second stage valve body 1
2 opens, and the upper liquid chamber 8 communicates with the lower liquid chamber 10 via the through hole 17, the internal space 8', the through hole 18, and the orifice 14, and the liquid pressure difference between the upper and lower liquid chambers 8 and 10 is reduced. disappears.

When the first piston 26 finishes rising, the second piston 26, which also serves as the upper oil chamber of the first piston 26, remains in this state.
An oil inlet/outlet port 3 is provided in the lower oil chamber 28 of the piston 27.
Add oil from 0 and move the second piston 27 further (S ₂ −
S ₁ ) Raise.

Due to this rise of the second piston 27, the first stage valve body 15 at the lower end of the spindle 4 further rises (S ₂ S ₁ ).
The second stage valve body 12 is pulled up by the same amount. the result,
The orifice 13 provided on the valve seat 6 opens,
The liquid flows from the liquid inlet port 9 to the upper liquid chamber 8 and through hole 1.
9, the liquid is sent directly to the liquid outlet port 11 via the orifice 13 and the lower liquid chamber 10. In other words, the valve is opened.

In the water pressure control valve of the present invention, a cylinder with multi-stage operation corresponding to the number of stages of the valve body is attached to the end in the direction of movement of the valve body when the valve is opened, and the piston rod of the cylinder is used as the spindle of the first stage valve body to control the valve body. The spindle is fixed in a cantilevered manner from the direction of body movement, and when the valve is opened, the valve body is pulled up rather than pushed up, so even if a large force is required to open the valve, the spindle is held straight, reducing buckling and breakage. can be reliably prevented from the root cause.

Moreover, by making the valve body as described above, the part 41 (see FIG. 1) of the spindle ahead of the valve body disappears, and as a result, the shaft sealing part 42 of the spindle,
42' of 42' (see Figure 1) disappears, the length of the spindle becomes smaller, and the retaining spring 38 of the valve body (see Figure 1) disappears, resulting in a larger width of the valve structure. Simplification is achieved.

Furthermore, in the water pressure control valve of the present invention,
Since the valve body is fixed at the stop position of the cylinder when the valve is closed, the valve body does not float up during this period, and stable valve opening and closing operations are guaranteed.

In this specification, a two-stage water pressure control valve has been described in detail, but it goes without saying that the present invention is effective for a three-stage valve.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the conventional structure of a water pressure control valve in which valve bodies are combined in multiple stages, and Fig. 2 is a vertical sectional side view showing the structure of an example of a multi-stage water pressure control valve in which the present invention is implemented. It is. In the figure, 1: Valve part, 2: Cylinder part, 3:
Connection tube, 4: Spindle (piston rod), 5: Box, 6: Valve seat, 7: Shaft seal, 8, 10: Liquid chamber, 12, 15: Valve body, 1
3, 14: Orifice, 16: Locking nut, 2
5: Cylinder tube, 26, 27: Piston, 28, 29, 32: Oil chamber, 38: Spring, 39: Lifting cylinder, 40: Piston nut.

Claims (1)

[Scope of utility model registration request] In a water pressure control valve in which valve bodies are assembled in multiple stages and other valve bodies follow the first stage valve body to open and close the valve, there is a mark at the end of the valve body movement direction when the valve is opened, depending on the number of stages of the valve body. 1. A water pressure control valve characterized in that a cylinder with multi-stage operation is attached thereto, and a piston rod tip of the cylinder is fixed to the first stage valve body as a spindle.