JPS62468Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pilot-operated switching valve that uses pilot fluid to move a main spool in the axial direction to selectively communicate flow paths.

Conventionally, this type of pilot operated switching valve has a sixth
As shown in the figure, the main spool 36, which has a pilot chamber 37 formed at its end and which switches and communicates the flow paths, is slidably fitted into the fitting hole 34 of the main valve body 33, and then attached to the main valve body 33. A supply passage P' for supplying pilot fluid from the pilot chamber 37 into the fitting hole 39 of the pilot valve body 38, and a discharge passage for connecting to the low pressure side.
A pilot spool 40 that communicates with the pilot chamber 37 is slidably fitted into the fitting hole 39, and an annular groove 41 that communicates with the pilot chamber 37 is formed by recessing the inner peripheral surface of the fitting hole 39. The inflow passage P' and the discharge passage R' are connected to the communication hole 42 and the communication hole 43 with a gap between them.
They are each opened through the openings. In the illustrated state, the electromagnetic device 44 is in a de-energized state, and the return spring 45
The pilot spool 40 is moved to the right operating position by the spring force, and the left end outer periphery of the switching control section 46 is located above the opening of the annular groove 41, communicating between the pilot chamber 37 and the discharge passage R', and the switching control section 46 is moved to the right operating position. Section 46
The outer peripheral portion of the right end fits into the fitting hole 39 to block the supply path P'. When the electromagnetic device 44 is energized from the state shown in the figure, the pilot spool 40 is moved to the left operating position by the attraction force of the electromagnetic device 44 against the spring force of the return spring 45, and the right end outer periphery of the switching control section 46 opens the annular groove 41. Pilot compartment 3 located above
7 and the supply path P', and the switching control section 4
The left end outer periphery of 6 fits into the fitting hole 39 and the discharge path is formed.
R' is shut off, and the main spool 36 is connected to the pilot chamber 3.
It moves to the left due to the acting force caused by the pilot fluid supplied to 7. In this state, when the electromagnetic device 44 is de-energized, the pilot spool 40 is operated to return to the illustrated position by the spring force of the return spring 45, and the pilot chamber 37 is switched to the non-outlet path R', and the main spool 36 is moved by the spring force of the spring. Pilot room 37
While discharging the pilot fluid to the discharge path R', it moves to the right and returns to the position shown.

However, the small electromagnetic device 44 and the return spring 4
5, the axial movement amount between the left and right operating positions of the pilot spool 40 is set short so as to obtain quick switching communication between the pilot chamber supply path and the discharge path, and the pilot chamber 37 and the supply path P At the left operating position of the pilot spool 40, which communicates between
In order to obtain good prevention of leakage of pilot fluid to R', the axial fitting amount of the outer periphery of the switching control part 46 of the pilot spool 40 that fits into the fitting hole 39 in the left operating position is set long. In the right operating position of the pilot spool 40, which communicates between the pilot chamber 37 and the discharge path R' and blocks the supply path P', the axial opening amount formed between the switching control part 46 and the annular groove 41 becomes small, and the pilot Foreign matter such as iron powder mixed in the pilot fluid discharged from the chamber 37 to the discharge passage R' is removed from the pilot chamber 37 and the discharge passage.
Since the pressure difference between R' is small, the opening is clogged and the pilot spool 40 malfunctions in the axial direction. To solve this problem, pilot spool 4
Switching control part 46 and annular groove 41 in the right operating position of 0
If the amount of the axial opening formed between the two is increased, the amount of axial operation of the pilot spool 40 must be increased by the increased amount of the axial opening, making it impossible to control the rapid switching of the pilot fluid. There were some drawbacks, such as it disappearing.

The present invention was devised in view of these drawbacks, and the axial movement amount of the pilot spool is made the same as that of the conventional valve, without impairing the operating function of the conventional valve, and the pilot fluid formed between the switching control part and the annular groove is The present invention provides a pilot operated switching valve which allows the axial opening amount for discharge to be easily increased.

Therefore, in the present invention, the main spool that switches and communicates the flow paths is slidably inserted into the fitting hole of the main valve body, and the pilot fluid is freely applied to the end of the main spool to the end surface of the main spool. A pilot spool that forms a chamber and connects the pilot chamber to a supply path for supplying pilot fluid and a discharge path that connects to the low pressure side can be freely slid into the fitting hole of the pilot valve body attached to the main valve body. The pilot spool is inserted into the fitting hole into which the pilot spool is fitted, and the inner peripheral surface of the fitting hole is recessed to form an annular groove communicating with the pilot chamber. The pilot spool is operated in the axial direction by an electromagnetic device and a return spring, and the pilot spool communicates between the pilot chamber and the supply channel in one operating position to block the discharge channel and operates in the other position. A switching control part is provided to communicate between the pilot chamber and the discharge passage and cut off the supply passage at the position, and the switching control part of the pilot spool, which cuts off communication between the pilot chamber and the discharge passage, is always fitted into the fitting hole. At the same time, a plurality of notches are provided by recessing a portion of the outer circumferential surface of the outer circumferential part that fits into the fitting hole, and the notches are formed at one operating position of the pilot spool by forming an annular groove on the inner circumferential surface of the fitting hole. The opening to the annular groove is closed and opens to the annular groove at the other operating position of the pilot spool, providing communication between the pilot chamber and the discharge passage.

In such a structure of the present invention, when the pilot spool is axially operated to one operating position, the switching control section closes the openings of the plurality of notches to the annular groove by the inner circumferential surface of the fitting hole and closes the openings between the pilot chamber and the supply path. to communicate and cut off the discharge path. Further, when the pilot spool is axially operated to the other operating position, the plurality of notches in the switching control section open into the annular groove to communicate between the pilot chamber and the discharge passage and to interrupt the supply passage. During axial operation of the pilot spool, the switching control section of the pilot spool, which has multiple notches, is always fitted into the fitting hole, so when the pilot spool is operated to one operating position, the switching control section The outer periphery other than the partial outer periphery with the notches can be largely fitted into the fitting hole in the circumferential direction, and the amount of axial fitting between the partial outer periphery with multiple notches and the fitting hole can be increased. With a small amount, leakage of pilot fluid from the pilot chamber to the discharge passage can be effectively prevented. Therefore, the amount of axial operation of the pilot spool is the same as that of conventional valves, and the amount of axial engagement between the notched outer circumferential surface and the fitting hole is minimized. When the operating position is activated, the axial opening amount of the notch into the annular groove can be increased, and good axial operation of the pilot spool can be obtained.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In Figures 1 to 3, 1 is a main body having a supply passage P for supplying pressure fluid, load passages A and B connected to the fluid actuator side, and discharge passages R ₁ and R ₂ connected to the low pressure side. The valve body has a fitting hole 3 that communicates with each flow path and forms large diameter holes 2A and 2B at both ends. A supply channel that branches from the supply channel P and supplies a part of the pressure fluid as a pilot fluid.
PA, PB and discharge passages RA and RB branching from discharge passages R ₁ and R ₂ are opened and communicated with each other. 4 is a main spool that is slidably inserted into the fitting hole 3, and is provided so as to control the flow direction of the fluid by switching communication between each of the flow paths P, A, B, _R1 , and _R2 . . 5 and 6 are screwed onto the end of the main valve body 1 to form a large diameter hole 2.
These are plugs and electromagnetic devices that seal and close A and 2B. Reference numeral 7 denotes a flow path member inserted into the large diameter hole 2A to form a pilot chamber 8A between it and the main spool 4, and between the inner surface of the large diameter hole 2A and the spring receiver 9 that abuts the main spool 4. is pressed toward the stopper 5 side by a spring 10 interposed in the
It communicates with the discharge flow path _R1 via RA. Reference numeral 11 denotes a pilot valve body which is inserted into the large diameter hole 2B to form a pilot chamber 8B between it and the main spool 4, and a spring 1 interposed between it and the inner surface of the large diameter hole 2B.
The pilot valve main body 11 has a bottom wall 13 inside and forms a fitting hole 14 that opens outward in the axial direction of the main valve main body 1. A communication hole 1 that communicates with the pilot chamber 8B is formed by recessing the inner peripheral surface of the annular groove 15.
6, and a communication hole 17 communicating with the inlet passage PB and a communication hole 18 communicating with the discharge passage RB are provided at intervals in the axial direction of the annular groove 15, respectively. Reference numeral 19 designates a pilot spool that is slidably inserted into the fitting hole 14 of the pilot valve body 11 and has the same working area at both ends, and is recessed inward from one end on the bottom wall 13 side to house the return spring 20. A hole 21 is provided, and both ends are communicated with each other by a communication hole 22 to balance the pressure, and an annular switching groove 23 is provided on the outer periphery so as to constantly communicate with the communication hole 17.
is formed. The switching control section 24 is formed to be longer than the axial width of the annular groove formed in the fitting hole 14 so that the pilot spool 19 is actuated in the axial direction so that the left end thereof is always fitted into the fitting hole 14. A plurality of notches 25 are provided at the left end outer circumferential portion by recessing a portion of the outer circumferential surface at intervals in the circumferential direction to balance the pressure. A plurality of notches 25 open into the annular groove 15 in the right operating position of the pilot spool 19 as shown in the upper half of FIG. The opening to the annular groove 15 is formed so as to be closed by the inner peripheral surface. 26 is the fixed core 2 of the electromagnetic device 6
This is an operating member that is slidably inserted into the pilot spool 19 and applies a suction force acting on the movable iron core 28 to the pilot spool 19.

Next, the operation of this configuration will be explained.

In FIG. 1, the electromagnetic device 6 is in a non-energized state, and the pilot spool 19 is biased by the spring force of the return spring 20 to be located at the right operating end position as shown in the upper half of FIG. The pilot chamber 8B is opened to the groove 15, and the pilot chamber 8B is opened to the communication hole 16 and the annular groove 1.
5. It communicates with the discharge passage RB through the notch 25, the storage hole 21, the communication holes 22 and 18, and becomes low pressure, and the main spool 4 is biased by the spring 10 and connects the supply passage P and the load passage at the right working end. B, the load flow path A and the discharge flow path _R1 are communicated with each other.

Now, when the electromagnetic device 6 is energized, a suction force acting on the movable iron core 28 is applied to the pilot spool 19 via the operating member 29, and the spring force of the return spring 20 is applied to the left operating end position as shown in the lower half of FIG. The switching groove 23 opens into the annular groove 15 and communicates between the communication holes 16 and 17, and the notch 2
The opening of No. 5 to the annular groove 15 is closed by the inner circumferential surface of the fitting hole 14, thereby blocking communication between the communication holes 16 and 18.
Then, the pilot fluid flows into the pilot chamber 8B from the supply channel P, flows through the supply channel PB, and the communication holes 16 and 17, and is controlled according to the axial movement of the pilot spool 19, and the main spool 4 acts on the end surface. Due to the acting force of the pilot fluid, spring 1
It operates to the left against a spring force of 0 to perform switching communication between each flow path. The fluid in the pilot chamber 8A is discharged from the discharge path RA.
is discharged into the flow discharge channel _R1 .

Furthermore, when the electromagnetic device 6 is de-energized, the pilot spool 19 is urged by the spring force of the return spring 20 and returns to the original position shown in the upper half of FIG. 2 while pressing the operating member 26 and the movable core 28. Then, a notch 25 is opened in the annular groove 15 and the switching groove 23 is closed.
The main spool 4 is discharged to a low pressure, and the spring 10
It is returned to its original position by the spring force _of
of fluid is inhaled.

In such an axial operation of the pilot spool 19, the switching control section 24 of the pilot spool 19, which has a plurality of notches 25, is always connected to the fitting hole 14.
, the pilot spool 19 is moved to the left operating position and the pilot chamber 8B and supply path are
When the discharge path RB is communicated with PB and the discharge path RB is blocked, the outer circumferential part other than the partial outer circumferential surface of the switching control part 24 provided with the plurality of notches 25 is largely fitted into the fitting hole 14 in the circumferential direction. By minimizing the amount of axial fitting between the partial outer circumferential surface provided with a plurality of notches 25 and the fitting hole 14, leakage of pilot fluid from the pilot chamber 8B to the discharge path RB can be effectively prevented. Therefore, the amount of axial operation of the pilot spool 19 is the same as that of the conventional valve, and the amount of axial engagement between the partial outer peripheral surface where the notch 25 is provided and the fitting hole 14 is slightly reduced.
The pilot spool 19 is moved to the right operating position to connect the pilot chamber 8B and the discharge passage RB to the supply passage.
The axial opening amount of the notch 25 into the annular groove 15 when shutting off the PB can be increased, the influence of foreign matter such as iron powder mixed in the pilot fluid can be reduced, and a good shaft of the pilot spool 19 can be achieved. Directional actuation is obtained. Also, pilot spool 19
Since the switching control part 24 is always fitted into the fitting hole 14, it is well fitted and held in the fitting hole 14, and light and quick axial operation can be obtained by a small electromagnetic device with a small suction force. . Furthermore, by appropriately changing the number of notches or the amount and width of the recess from the outer circumferential surface of the switching control section 24, the discharge flow rate of the pilot fluid can be adjusted, and the optimum operation control of the main spool 4 can be easily obtained. can.

4 and 5 show other embodiments. In FIG. 4, notches 29 and 30 are provided at both ends of the switching control section 24 of the pilot spool 19, and the pilot fluid in the pilot chamber is inflowed and discharged through the notches. FIG. 5 shows a pilot valve main body 32 attached to the end face of a main valve main body 31 so as to obtain the same effect as described above.

In this way, the present invention slidably fits the main spool that switches and communicates the flow paths into the fitting hole of the main valve body, and allows the pilot fluid to freely act on the end of the main spool to the end face of the main spool. form the pilot chamber,
A pilot spool that connects the pilot chamber to a supply path that supplies pilot fluid and a discharge path that connects to the low pressure side is slidably inserted into the fitting hole of the pilot valve body attached to the main valve body. ,
The inner circumferential surface of the fitting hole into which the pilot spool is inserted is recessed to form an annular groove communicating with the pilot chamber, and a supply passage is provided inside the fitting hole with a space in the axial direction from the annular groove of the fitting hole. The pilot spool is operated in the axial direction by an electromagnetic device and a return spring, and in one operating position it communicates between the pilot chamber and the supply channel and blocks the discharge channel, and in the other operating position it communicates with the pilot chamber and the supply channel. A switching control part is provided to communicate between the passages and cut off the supply passage, and a switching control part of the pilot spool that disconnects communication between the pilot chamber and the discharge passage is formed so as to always fit with the fitting hole, A plurality of notches are provided by recessing a portion of the outer circumferential surface of the fitting hole, and the opening to the annular groove is closed by the inner circumferential surface of the fitting hole when the notches are formed at one operating position of the pilot spool. By opening into the annular groove at the other operating position of the pilot spool and providing communication between the pilot chamber and the discharge passage,
The axial movement amount between the two operating positions of the pilot spool is the same as that of conventional valves, and the axial opening amount into the annular groove of the notch at the other operating position of the pilot spool can be increased, resulting in a good flow from the pilot chamber to the discharge path. This provides excellent pilot fluid leakage prevention. Furthermore, since the axial opening amount for discharging the pilot fluid can be increased, the influence of foreign matter such as iron powder mixed in the pilot fluid can be reduced, and good inward movement of the pilot spool can be obtained. Moreover, since the switching control part of the pilot spool is always fitted into the fitting hole, it is well fitted and held in the fitting hole, and a small electromagnetic device with a small suction force allows light and quick axial movement. can get. Furthermore, by appropriately changing the number of notches or the amount and width of the recess from the outer circumferential surface of the switching control part, the discharge flow rate of the pilot fluid can be adjusted and the optimum operation control of the main spool can be easily obtained. It has characteristics.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a pilot operated switching valve showing an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the main part of the pilot valve section, and Fig. 3 is a sectional view taken along the line - in Fig. 2. , Figures 4 and 5 are other embodiment diagrams, and Figure 6
The figure is a diagram of a conventional example. 1... Main valve body, 4... Main spool, 11...
Pilot valve body, 15... Annular groove, 19... Pilot spool, 24... Switching control section, 25,
29, 30... Notch.

Claims (1)

[Scope of utility model registration request] A main spool that switches and communicates the flow paths is slidably inserted into the fitting hole of the main valve body, and a pilot chamber is formed at the end of the main spool so that the pilot fluid can be freely applied to the end face of the main spool. A pilot spool is slidably inserted into the fitting hole of the pilot valve body attached to the main body, which connects the pilot chamber to a supply path for supplying pilot fluid and a discharge path connecting to the low pressure side. The inner circumferential surface of the fitting hole into which the spool is inserted is recessed to form an annular groove that communicates with the pilot chamber, and a supply path and discharge are provided inside the fitting hole with a gap in the axial direction from the annular groove of the fitting hole. The pilot spool is axially actuated by an electromagnetic device and a return spring, and in one operating position it communicates between the pilot chamber and the supply channel and blocks the discharge channel, and in the other operating position it connects the pilot chamber and the discharge channel. A switching control section of the pilot spool is provided to communicate between the pilot chamber and the discharge channel and cut off the supply path, and a switching control section of the pilot spool that disconnects communication between the pilot chamber and the discharge channel is formed so as to always fit into the fitting hole and A plurality of notches are provided by recessing a portion of the outer circumferential surface of the outer periphery to be fitted, and the opening to the annular groove is closed by the inner circumferential surface of the fitting hole when the notches are formed at one operating position of the pilot spool. A pilot operation switching valve that opens into an annular groove at the other operating position of the spool and communicates between the pilot chamber and the discharge passage.