JPH018724Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a spool valve that can introduce compressed air into a pneumatic circuit and discharge the air as necessary. When introducing compressed air, without injecting high pressure air,
It will be provided gradually.

[Conventional technology]

In pneumatic circuits, the compressed air in the circuit is exhausted during inspection and adjustment, and to prevent equipment from malfunctioning due to air leakage after work is completed.
Therefore, when the valve is fully opened and air pressure is introduced into the circuit again at the start of work, the secondary circuit, which is at almost atmospheric pressure, is rapidly pressurized, the cylinder attached to the end of the circuit is activated rapidly, and the piston rod is There is a risk that the product may fly out and have an adverse effect on other equipment for which preparations have not been completed in advance, or pose a danger to the human body.

This is because the back pressure has disappeared in both chambers of the piston, so when air pressure is introduced into one chamber, the piston moves rapidly until the air in the other chamber is compressed, so the speed adjustment is necessary. Unable to do so, the piston goes out of control.

Conventionally, when reintroducing air pressure after the residual pressure has been discharged, air pressure is gradually introduced using a manually operated valve to prevent the cylinder from running out of control. but,
Since air pressure is introduced while adjusting the speed, it takes time and effort to operate the valve and is inconvenient to handle.

In order to solve such problems,
As described in Publication No. 126107, a configuration is proposed that includes a pilot valve and a main valve, supplies compressed air from the pilot valve and check valve to an air cylinder, etc., and opens the main valve after reaching a predetermined pressure. has been done.

[Problem that the invention attempts to solve]

However, in such a configuration, compressed air is supplied to the air cylinder etc. after the main valve body moves to the neutral position, so it takes time to start supplying compressed air to the air cylinder etc., resulting in poor responsiveness. bad. Furthermore, since the compressed air that flows in from the input port is throttled by the throttle valve before being supplied to the main valve element drive section, the responsiveness further deteriorates. Furthermore, since the operation of the main valve body and check valve must be adjusted only by the amount of restriction by the throttle valve, the pressure is unstable and the reliability of adjustment is poor. When controlling multiple air cylinders, the pressure of each air cylinder will be uneven due to the load. In this case, the operation of the check valve will become unstable, and as a result, the operation of the main valve element will also be affected. Becomes unstable.

The technical problem of this invention is to solve these problems, to be able to supply compressed air to air cylinders etc. simultaneously with the operation of the pilot switching valve, to be able to control and adjust each part accurately, and to provide a stable system. The goal is to create pressure.

[Means for solving problems]

In a spool valve, a spool is built into a body in which an output port, an input port, and a discharge port are arranged on the side, and the output port is switched between an input port and a discharge port by the movement of the spool. A small valve hole _V4 communicating with the input port is provided on the sliding surface between the input port and the output port. When switching the spool from the discharge position to the supply position, this small valve hole V ₄
The spool is moved to two stages: an intermediate position where the input port and the output port communicate with each other via the spool, and a fully open supply position where the input port and the output port communicate with each other. That is, at one end of the spool in the moving direction, there is provided a pressing means for moving the spool from the supply position to the discharge position. At the other end of the moving direction,
The piston 14 is pressurized by a switching valve and drives the spool against the pressure means. It also includes a delay means and a spool pressurizing circuit for sucking and discharging compressed air at the end of the spool. In addition, a small valve hole communicating with the input port and a valve hole opened subsequent to the small valve hole are provided on the surface of the main body where the spool contacts slidingly between the input port and the output port, so that the direction of movement of the spool is adjusted. One end is provided with a pressing means for moving the spool from the supply position to the discharge position,
A spool pressurizing circuit including a piston pressurized by the switching valve and a delay means is disposed at the other end.

[Effect]

Therefore, when the driving force of the piston and spool is removed, the spool is moved to the discharge position by the elastic pressure means, the output port and the discharge port communicate with each other, and the compressed air on the circuit side is discharged.

When the piston and spool are driven, the piston operates first because the spool drive side is equipped with a delay means by the throttle valve side. When the piston operates, the spool is moved to an intermediate position against the elastic force of the elastic pressure means, and the output port is communicated with the small valve hole _V4 communicating with the input port. For this reason,
The controlled fluid gradually flows into the output port. Next, after a certain period of time has elapsed due to the delay means, only the spool is activated and moves from the intermediate position to the supply position, the input port and output port are in communication and are fully open, supplying a large amount of compressed air to the circuit side. .

〔Example〕

Next, how the spool valve according to the present invention is actually implemented will be explained using examples. 1A and 1B are a sectional view and a bottom view of the spool valve according to the present invention with the spool in the discharge position, FIG. 2 a sectional view with the spool in the intermediate position, and FIG. 3 a sectional view with the spool in the supply position. A sleeve 2 is inserted into the main body 1 of the spool valve, and a spool 3 is built into the sleeve 2. Inside the main body 1, there is an input port P ₁
Output port P ₂ and discharge port P ₃ are opened, and input port P ₁ , output port P ₂ and discharge port P ₃ are formed in an annular groove C ₁ which contacts the outer periphery of sleeve 2.
Connected to C ₂ and C ₃ . In sleeve 2,
Valve holes V ₁ , V ₂ and V ₃ are bored at positions corresponding to these annular grooves C ₁ , C ₂ and C ₃ . Also,
The sleeve 2 between the valve holes _V1 and _V2 has a small valve hole _V4 .
is open. This small valve hole _V4 communicates with an annular groove _C1 that communicates with the input port _P1 . The contact surfaces between the main body 1 and the sleeve 2 other than the annular grooves C ₁ to _{C 3} are sealed by O-rings 4, 4, . . . .

A cap 5 is fixed to the end of the main body 1 in the spool movement direction on the input port _P1 side. A return spring 7 consisting of a compression spring is interposed between the threaded sleeve 6 screwed into the cap 5 and the spool 3, and presses the spool 3 in the direction of movement toward the discharge port _P3 . By this return spring 7, the spool ₃ is moved to the left end discharge position as _shown in FIG _. Exhaust port _P3 communicates and compressed air on the circuit side is exhausted. The spring force of the return spring 7 can be adjusted by loosening the fixing nut 9 and rotating the screw sleeve 6.

On the other hand, a piston chamber 10 is provided at the end of the main body 1 in the spool movement direction on the discharge port _P3 side. This piston chamber 10 is formed in a flanged sleeve 11 inserted into the main body 1,
A flange 12 of the sleeve 11 separates the piston chamber 10 from the spool chamber 13. A piston rod 15 of a piston 14 housed in the piston chamber 10 is slidably inserted into an axial hole 16 formed at the left end of the spool 3 through the flange 12. When the spool 3 is at the left end discharge position, the piston 14 is pushed by the piston rod 15 and positioned at the left end of the piston chamber 10. Further, the space between the main body 1 and the flanged sleeve 11 is sealed by an O-ring 17, and the space between the flange 12 and the piston rod 15 is sealed by a packing 18, respectively.

Compressed air is supplied and discharged from the input port P ₁ to the piston chamber 10 by a pilot switching valve 20 attached to a head cover 19 . The head cover 19 includes a secondary port 21 that communicates between the switching valve 20 and the piston chamber 10, and an introduction port 2 that communicates between the switching valve 20 and the introduction path 22 from the input port _P1 .
3 are open each. The compressed air in the secondary port 21 is then transferred to a communication path 2 provided in the main body 1.
4, it is also supplied to and discharged from the spool chamber 13 at the left end of the sleeve 2 via the throttle valve 25.

Now, when the secondary port 21 is opened to the atmosphere by the pilot switching valve 20 and the introduction port 23 is shut off, the compressed air in the piston chamber 10 and spool chamber 13 is discharged. Therefore, the spool 3 is moved by the return spring 7 to the discharge position as shown in _{FIG .}
Output port P ₂ and exhaust port P ₃ are communicated via, and compressed air from the circuit side is discharged.

Next, when the pilot switching valve 20 is switched to connect the secondary port 21 and the introduction port 23,
Compressed air is supplied to the piston chamber 10 from the input port P ₁ via the introduction path 22 . Secondary side port 2
The compressed air supplied from 1 to the piston chamber 10 is
Furthermore, it is gradually supplied to the spool chamber 13 from the communication path 24 via the throttle valve 25. Therefore, the spool 3 moves to the right in FIG. 1, but there is a difference in pressure receiving area between the piston 14 and the spool 3.
Since the difference in the amount of compressed air supplied by the throttle valve and the elastic force of the return spring 7 act on the spool 3, the spool 3 moves to the right by the piston stroke l ₁ mainly due to the pressing force of the piston 14. It is moved and stopped at an intermediate position as shown in FIG. In this intermediate position, the input port P ₁ and the output port P ₂ are communicated through the small diameter portion 8 of the spool 3 through the valve hole V ₂ and the small valve hole V ₄ , and compressed air is delivered to the small valve hole on the output port P ₂ side. Gradually fed from V ₄ .

Even while spool 3 is stopped at the intermediate position,
Compressed air in the secondary port 21 gradually flows into the spool chamber 13 via the throttle valve 25. After a certain period of time has elapsed and the pressure in the spool chamber 13 increases enough to exceed the elastic force of the return spring 7, only the spool 3 is moved to the right by a stroke _l2 in FIG. 2 from the intermediate position to the supply position. . In the supply position, as shown in FIG. 3, the valve hole V ₁ , small valve hole V ₄ and valve hole V ₂ are aligned with the small diameter portion 8 of the spool 3, and the input port P ₁ and the output port P ₂ are in communication. Furthermore, the valve becomes fully open.

In this way, in the intermediate position the output port P ₂
After gradually supplying compressed air to the circuit side and increasing the air pressure on the circuit side, the spool 3 is automatically moved to the supply position and fully opened, making it safe to reintroduce air pressure and easy to handle. Become.

Moreover, the transition time from the intermediate position shown in FIG. 2 to the fully open supply position shown in FIG. By this,
In addition, the time difference between the piston 14 and the spool 3 driven by air pressure can be adjusted by adjusting the opening degree of the throttle valve 25.

FIG. 4 shows the throttle valve 2 provided in the communication passage 24.
FIG. 5 is a partial sectional view showing another embodiment of the delay means. Switch the pilot switching valve 20 to open the piston chamber 10 and spool chamber 13 to the atmosphere,
When the spool 3 is returned to the discharge position shown in FIG. 1, it can be returned quickly by providing a check valve 26 that allows flow only from the spool chamber 13 to the secondary port 21 side.

FIG. 5 is a partial sectional view showing another embodiment of the pressure means. In this embodiment, the return spring 7 is interposed between the spool 3 and the cap 5,
The force of compression remains constant. Separately from the return spring 7, a spool delay spring 30 is provided which is guided by a spring guide 28 of the pressure regulating screw 27, has one end fixed to the pressure regulating screw 27, and has a free end 29 at the other end. This free end 29 is arranged near the right end of the spool 3 at an intermediate position.
Therefore, only the elastic force of the return spring 7 acts on the spool 3 from the discharge position to the intermediate position, and the elastic force of the spool delay spring 30 is further applied from the intermediate position to the supply position. Therefore, the spool 3 is always moved with constant air pressure from the discharge position to the intermediate position, and by adjusting the elastic force of the spool delay spring 30, it is possible to reliably set only the transition time from the intermediate position to the supply position. .

As described above, according to the present invention, when the residual pressure in the pneumatic circuit is discharged and the pneumatic pressure is reintroduced, at first,
Compressed air is gradually introduced into the output port side from the small valve hole V ₄ , and then the spool is moved to the fully open supply position, preventing a large amount of compressed air from suddenly flowing from the input port to the output port. Therefore, dangers such as cylinder runaway can be avoided. Moreover, since the spool is automatically shifted to the fully open state by two driving means (spool driving by a piston and independent movement of the spool) that operate with a time difference, handling operations are facilitated.

[Effect of idea]

As described above, according to the present invention, when introducing air pressure again after discharging the residual pressure in the pneumatic circuit, the air pressure is initially introduced gradually from the small valve hole V ₄ at the intermediate position. Since the spool immediately moves to the intermediate position, the controlled fluid can be supplied to the air cylinder etc. simultaneously with the operation of the pilot switching valve 20, resulting in excellent responsiveness. After the controlled fluid is gradually supplied to the air cylinder or the like in this way, the spool moves to the fully open supply position, making it possible to prevent a large amount of compressed air from rapidly flowing from the input port to the output port. Further, since the operations of the piston 14 and the spool 3 can be adjusted by the spring pressure of the return spring 7 and the throttle valve 25, the adjustments can be made accurately and with high precision. When driving multiple air cylinders, etc.,
The input port and output port are in communication through the small valve hole _V4 from the start of the supply of controlled fluid, and there is no check valve, so even if pressure variations occur between each air cylinder, operation will continue. is never unstable.

[Brief explanation of the drawing]

The figure shows an embodiment of the spool valve according to the invention,
Figure 1 A and B are cross-sectional views and bottom views with the spool in the ejection position, Figure 2 is a cross-sectional view with the spool in the intermediate position, Figure 3 is a cross-sectional view with the spool in the supply position, and Figure 4 shows different delay means. FIG. 5 is a partial sectional view showing another embodiment of the pressure means. In the figure, 1 is the main body, 3 is the spool, 7 is the return spring, 8 is the small diameter part, 10 is the piston chamber,
13 is a spool chamber, 14 is a piston, 20 is a pilot switching valve, 21 is a secondary side port, 23 is an introduction port, 25 is a throttle valve, _P1 is an input port, _P2 is an output port, _P3 is a discharge port, V ₁ , V ₂ , and V ₃ are valve holes, and V ₄ is a small valve hole communicating with the input port P ₁ .

Claims (1)

[Scope of Claim for Utility Model Registration] A spool valve in which a spool is built into a main body in which an output port, an input port, and a discharge port are arranged on the side, and the output port is switched between an input port and a discharge port by movement of the spool, A small valve hole communicating with the input port and a valve hole opened subsequent to the small valve hole are provided on the surface of the main body where the spool between the input port and the output port slides, and at one end in the moving direction of the spool. By providing a pressure means for moving the spool from a supply position to a discharge position, and arranging a spool pressurizing circuit having a piston pressurized by the switching valve and a delay means at the other end, A spool valve characterized in that the spool is moved in two stages from a discharge position to a supply position.