JPH0337069B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spool position control device that moves a spool at high speed following an input member.

[Conventional technology]

Conventionally, as this type of spool position control device, there has been one shown in FIG. 11, for example.

To explain this simply, a spool 2 is housed in the valve body 1 and is biased in the valve closing direction by a spring 3. Inside the spool 2, a passage having an orifice 4 is connected to the input port 5 and the back of the spool. A passage 9 is provided to communicate with the pressure chamber 6 and further has a conical opening 8 communicating between the back pressure chamber 6 and the outlet port 7.

This spool 2 forms an orifice 11 between it and the tip of the input rod 10.
follow. That is, when the input rod 10 is pushed to the right in the figure, the orifice 11 is closed and the pressure in the back pressure chamber 6 is increased, and the right edge of the spool 2 is brought into close contact with the seat part 12 as shown in the figure, and the inlet port 5 is closed. and the outlet port 7 is closed.

When the input rod 10 is moved to the left, the spool 2 follows and moves to the left, and the seat part 1
Open the flow path away from 2.

[Problem that the invention seeks to solve]

However, in such a conventional spool position control device, the input rod 10 has a simple rod shape and protrudes outward from the back pressure chamber 6, so the pressure at the outlet port 7 acts on the cross-sectional area of the input rod 10. Was.

Therefore, in order to make the spool 2 track at extremely high speeds, it is necessary to significantly enlarge the diameter of the input rod 10 as well as the opening 8 and the passage 9, while the outlet port 7 is connected to an external load device. In this case, a large ejection force will be applied to the input rod 10. Therefore, there was a problem in that a large input control device was required.

The object of the present invention is to solve these problems of the conventional device.

[Means for solving problems]

Therefore, in the high-speed spool position control device according to the present invention, the input rod of the spool position control device as described above is slidably inserted into the sliding hole of the valve body, and its tip is projected into the back pressure chamber of the spool. An orifice is formed between the valve body and the opening of the spool, while an operating rod is provided at the rear end to protrude outside the valve body, and an oil chamber is formed between the sliding hole and the input rod. The input rod is provided with a passageway for introducing the pressure of the back pressure chamber side opening of the spool into the oil chamber.

[Effect]

By guiding the pressure at the back pressure chamber side opening of the spool through the passage provided with the input rod in the oil chamber, the force in the ejection direction due to the pressure at the outlet port acting on the input rod is balanced, and the operating rod can be operated with a small operating force. It becomes possible to control the spool position at high speed.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a sectional view showing a first embodiment of the invention.

Valve body 20 of this high-speed spool position control device
The spool 21 housed inside has a poppet shape, and a cylindrical V-cut 2 is formed at the tip of the spool 21 between the inlet port 22 and the outlet port 23.
1a controls the opening of the channel. This spool 21
is biased by a spring 25 provided in the back pressure chamber 24 in a direction to close the opening of the flow path.

Then, the pressure of the inlet port 22 is applied to one surface 21b of this spool 21 (the tapered surface on the right side in the figure), and the back pressure chamber 2 to which the other surface is exposed
4, a passage 27 is formed in the valve body 20 through which pilot oil flows from the inlet port 22 through the orifice 26, and a passage 21c is formed in the spool 21 along its central axis to communicate the back pressure chamber 24 with the outlet port 23. is formed. The opening of this passage 21c on the back pressure chamber 24 side is a conical opening 21d.

On the other hand, the input rod 28 is slidably inserted into a sliding hole 29 formed in the valve body 20.
The tip thereof is projected into the back pressure chamber 24 and an orifice 30 is formed between it and the opening 21d of the spool 21. It flows out to the outlet port 23 through the inner passage 21c.

Further, at the rear end of the input rod 28, an operating rod 31 that protrudes to the outside of the valve body 20 is provided integrally with the input rod 28, as shown in FIG. Then, the sliding hole 29 and the input rod 28
An oil chamber 32 is formed between the two.

Furthermore, a large diameter passage 2 is inserted along the central axis of the input rod 28 from the distal end surface (the right end surface in the figure).
8a, and a pair of small passages 28b, 2 are provided on both sides of the operating rod 31 from the rear end surface (left end surface in FIG. 1).
8b is bored to communicate with the passage 28a, and the spool 2 is inserted into the oil chamber 32 through the passages 28a and 28b.
It is configured to guide the pressure of the opening 21d of No. 1.

The operating principle of _this embodiment is the same as that of the conventional example shown in FIG. Since a large amount can be discharged, it is possible to make the spool 21 follow the displacement of the input rod 28 at high speed.

In addition, the member protruding outward is a thin operating rod 31, and its protruding force is due to the outlet port pressure applied to the cross-sectional area of diameter _D2 .
Even if the diameter of the input rod 28 is made sufficiently large, it can be reduced to a small value.

According to this embodiment, the force relationship of the input rod 28 is such that the pressure in the oil chamber 32 is equal to the pressure in the passage 21c of the spool 21.
Even if the pressure at the outlet port 23 is high, it is almost balanced, and the ejection force is only applied to the operating rod 31 (diameter D ₂ ).

Therefore, the operating rod 31 can be displaced with a small operating force, and the position of the spool 21 can be controlled at high speed.

FIG. 3 shows a second embodiment of the present invention, in which the same parts as in FIG. 1 are given the same reference numerals, and their explanation will be omitted.

In this embodiment, the pilot oil pressure source 33
The pilot oil is supplied to the orifice 2 from the pilot oil pressure supply port 34 formed in the valve body 20.
6 into the back pressure chamber 24.

In addition, the input rod 38 is integrally provided with an operating rod 31 in substantially the same way as the input rod 28 of the first embodiment, forming passages 38a and 38b, but has a large diameter at the rear end where the oil chamber 32 is formed. A portion 38c is provided, and an oil chamber 35 formed by the difference between its diameter D ₃ and the diameter D ₁ of the main body including the tip portion is connected to a tank port 36 that communicates with the tank 37 .

The diameter D ₃ of this large diameter portion is (π/4)・D ₂ ² ≧ <
(π/4)·(D ₃ ² −D ₁ ² ) is determined as appropriate. In other words, the large diameter portion 38c is thicker than the main body by the radial cross-sectional area of the operating rod 31 D ₂ ² =
In the case of D ₃ ² -D ₁ ² , the forces acting on the input rod 38 are balanced and the operating force may be extremely small.
In addition, in the case of D ₂ ² <D ₃ ² −D ₁ ² , the input rod 3
8 is always drawn inward, and when the external operation pulling force is removed, the input rod itself is drawn in, and the spool 21, which is the main valve, also moves to the right, closing the flow path between the inlet port 22 and the outlet port 23. .

There are various types of external operating means, such as an electromagnetic actuator and a hydraulic system, but the illustrated example uses a proportional solenoid 39 with a position sensor, and in this case, highly accurate control is possible.

FIG. 4 shows a third embodiment of the present invention, in which the same parts as in FIGS. 1 and 3 are denoted by the same reference numerals, and their explanation will be omitted.

In this embodiment, a spool 41 having a substantially equal area is used, and the back pressure chamber 24 is communicated with the outlet port 43 through a T-shaped passage 41c formed inside the spool 41. Note that the arrangement of the inlet port 42 and the outlet port 43 is reversed from that in the first and second embodiments.

Further, in this embodiment, a shuttle valve 44 is provided,
Normally, pilot oil is supplied from the inlet port 42 through the passage 45, but another pilot oil pressure source 3 is supplied.
Pilot oil can also be supplied from 3 through a pilot oil pressure supply port 46. That is, external pilot operation is possible.

Further, the input rod 48 has passages 48a, 48b and a large diameter portion 48c, similar to the input rod 38 of the second embodiment, but also has a tip portion 48d.
is formed to be thicker (diameter D ₄ ) than the main body (diameter D ₁ ).

Therefore, the pressure of the back pressure chamber 24 acts on the area formed by the difference between the diameters D ₄ and D ₁ .
An inward pulling force acts.

On the contrary, the tip is made thinner than the main body (D ₄ < D ₁ )
In this case, a protruding force to the left in the figure acts. These relationships are determined by taking fluid forces into consideration. Also,
The diameter D 3 of the large diameter portion _48c is determined by adding fluid force to the relationship (π/4) (D ₃ ² −D ₄ ² )=(π/4) D ₂ ² .

FIG. 5 shows a fourth embodiment of the present invention;
Components similar to those in FIG. 3, FIG. 3, and FIG. 4 are designated by the same reference numerals, and their description will be omitted.

In this embodiment as well, a spool 51 having a substantially equal area is used, but the back pressure chamber 24 is communicated with the outlet port 43 through an L-shaped passage 51c formed inside the spool 51.

Also, this spool 51 has an orifice 51d.
A passage 51e is formed, and this passage 5
Pilot oil is made to flow into the back pressure chamber 24 from the inlet port 42 through 1e.

Furthermore, a solenoid valve 52 and an orifice 5 are also provided externally.
3 is inserted, and connected to ports 55 and 56 formed in the body 20, so that pilot oil can also flow from the inlet port 42 into the back pressure chamber 24 through this path. It consists of

The operating rod 31 can be operated with high precision by a proportional solenoid 39 equipped with a position sensor.

By the way, the purpose of this invention is to enable high-speed movement of the spool in one direction with a small operating force.
Moving the spool in the other direction is not considered, so
Generally, a small pilot flow rate determined by the orifice diameter is sufficient. However, if it is desired to control movement in the other direction at high speed, it is sufficient to increase the pilot flow rate by increasing the orifice diameter only during the spool movement.

This fourth embodiment is used in such cases.

FIG. 6 shows a fifth embodiment of the present invention, in which the same parts as in FIG. 3 are given the same reference numerals, and their explanation will be omitted.

The spool 61 in this embodiment is poppet-shaped, and like the spool 21 of FIGS.
Although it has a cut 61a and a tapered surface 61b, the opening 61d on the back pressure chamber 24 side of the passage 61c that communicates the back pressure chamber 24 with the outlet port 23 is slightly larger than the diameter D ₁ of the tip of the input rod 38. It is formed as a recessed step with a large diameter.

Also, this spool 61 has an orifice 61.
A passage 61f having a diameter of 1.e is formed, and pilot oil is made to flow into the back pressure chamber 24 from the inlet port 22 through this passage 61f.

By the way, the spool is controlled to follow the input rod, but if the input rod is moved at an extremely high speed, the spool will move with a certain degree of positional delay, and it is conceivable that the input rod and spool will eventually collide.

In this embodiment, the orifice 60 is formed by the tip of the input rod 38 and the opening 61d of the spool 61.
The spool 61 is formed in a two-stage constriction shape, and before the spool 61 collides with the input rod 38 at high speed, a cushioning action is performed to decelerate the spool 61, and position tracking is performed thereafter.

7 is an enlarged view of the main part of FIG. 6, and FIG. 8 is a speed diagram thereof. For example, if the input rod 38 momentarily moves to the position shown in the upper side of FIG. 7, the spool 61 The pressure oil in the back pressure chamber 24 is discharged into the passage 61c as shown by the arrow A, and the spool 61 moves at high speed in the direction of the arrow B due to the discharge flow rate.

Then, the corner a of the spool 61 is connected to the input rod 3.
As the corner d of 8 is approached, the area becomes rapidly closed. Thereafter, as the tapered part b and then the cylindrical part c successively cover the corner part d, the speed is further reduced, and finally the opening degree x corresponding to the orifice 60 is reached, as shown on the lower side of FIG. The position is determined by

In addition, as shown in FIG. 7a, the input rod 38
When the gap between the outer diameter of the input rod 38 and the cylindrical surface c of the spool 61 is reduced to create a tight fit, the spool 61 will fit into the tip corner d of the input rod 38.
and a forming orifice 6 formed by a tapered portion b.
0' is set to an amount commensurate with the orifice 60.

In this case, the tip of the input rod 38 and the cylindrical surface part c
There is a considerable distance from the bottom of the plane, so there is no risk of collision. Furthermore, by providing a notch or the like at the tip of the input rod 38, it is possible to further slow down the speed change during positioning.

FIG. 9 is an enlarged sectional view of essential parts showing only the orifice forming portion of the sixth embodiment of the present invention.

In this embodiment, the back pressure chamber side opening 71d of the passage 71c formed in the spool 71 is formed into a conical shape, and the tip 78d of the input rod 78 is made thinner than the main body and formed into a stepped shape. The opening 71d of the spool 71 is made into a tapered surface.
An orifice 70 is formed between the
It has the same cushioning effect as the fifth embodiment described above.

According to these fifth and sixth embodiments, even if the spool is followed and moved at an extremely high speed, the input rod and the spool will not collide and be damaged.

FIG. 10 shows a seventh embodiment of the present invention, in which the first
Components similar to those in the figures and FIG. 4 are designated by the same reference numerals.

This embodiment is an example in which the spool drive and the switching line by the spool are separated, and the spool 8
1 has an inlet port 82 and an outlet port 83 on its outer periphery.
A passage 81c formed along the central axis has a land portion 81a that opens and closes the main flow path between the tank 37 and a tapered surface 81b that receives the pilot oil pressure from the pilot oil pressure supply port 84.
The tank port 85 is connected to the tank port 85.

According to this embodiment, various flow path switching is possible depending on the shape of the land portion 81a of the spool 81.

〔Effect of the invention〕

As described above, the high-speed spool position control device according to the present invention can move the spool at extremely high speed while following the position of the one-way input rod.

Moreover, the operating force of the input rod can be extremely small, and the operating force can be reduced to zero or in the direction of protrusion or retraction.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing a first embodiment of the invention, FIG. 2 is a perspective view of the main parts of the input rod as seen from the rear end side, and FIG. 3 is a second embodiment of the invention. FIG. 4 is a longitudinal sectional view showing a third embodiment of the invention, FIG. 5 is a longitudinal sectional view showing a fourth embodiment of the invention, and FIG. 6 is a longitudinal sectional view showing a fifth embodiment of the invention. 7 is an enlarged explanatory view of the main part of Fig. 6, Fig. 7a is an enlarged explanatory view of the main part showing a slightly different example of the same part as Fig. 7, and Fig. 8 is the same FIG. 9 is an enlarged cross-sectional view of a main part of a sixth embodiment of the present invention, and FIG. 10 is a longitudinal cross-sectional view of a seventh embodiment of the present invention. FIG. 11 is a longitudinal sectional view showing an example of a conventional spool position control device. 20... Valve body, 21, 41, 51, 61,
71, 81... Spool, 22, 42, 82...
Inlet port, 23, 43, 83... Outlet port,
24... Back pressure chamber, 25... Spring, 26, 51
d, 53, 61e... Orifice, 28, 38,
48, 78...Input rod, 29...Sliding hole, 3
0,60,70...Forming orifice, 31...Operation rod, 32,35...Oil chamber, 34,46,8
4...Pilot oil pressure supply port, 39...Proportional solenoid with position sensor.

Claims (1)

[Scope of Claims] 1. A spool that continuously adjusts the opening degree depending on the position between an inlet port and an outlet port formed in a valve body, and an input rod that controls the position of the spool, the spool The pressure of the inlet port or the pilot hydraulic pressure supply port is applied to one side of the spool, and the other side is exposed to the back pressure chamber in which the spool is housed. The spool is provided with a passage that opens into the back pressure chamber and communicates with the outlet port or the tank port, and the pilot oil flowing into the back pressure chamber from the orifice is passed through the opening of the passage. In the spool position control device, the spool position control device is configured to cause the spool to flow from between the input rod and the tip end of the input rod to the outlet port or the tank port, and controls the position of the spool by following the input rod. It is slidably inserted into the sliding hole of the valve body, and its tip protrudes into the back pressure chamber, and the tip and the opening of the spool form an orifice. An operating rod is provided that protrudes from the outside of the valve body, an oil chamber is formed between the sliding hole and the input rod, and a passage is provided in the input rod for guiding the pressure of the opening of the spool to the oil chamber. A high-speed spool position control device characterized by: 2. The high-speed spool position control device according to claim 1, wherein the input rod has a tip diameter _D4 that is larger than a diameter _D1 of the main body that fits into the sliding hole. 3. The high-speed spool position control device according to claim 1, wherein the input rod has a tip diameter _D4 that is smaller than a diameter _D1 of the main body that fits into the sliding hole. 4. The high-speed spool position control device according to claim 1, wherein the input rod has a tip diameter _D4 equal to a diameter _D1 of the main body fitted into the sliding hole. 5. The input rod has a large diameter portion between the main body and the operating rod, which is thicker than the diameter _D4 of the main body,
The pressure led to the oil chamber is applied to the area formed by the difference between the diameter D ₃ of the large diameter portion and the diameter D ₂ of the operating rod, while the difference in diameter between the large diameter portion and the main body portion The high-speed spool position control device according to any one of claims 2 to 4, characterized in that an oil chamber formed by a tank port is connected to a tank port. 6 The shape of the tip of the input rod and the opening of the spool should be adjusted so that the opening amount of the orifice formed by the two mentioned above becomes the regular opening amount when the two approach each other until they reach the proper relative position. The high-speed spool position control device according to any one of claims 1 to 5, characterized in that the spool position control device is configured to gradually or stepwise reduce the spool position. 7. The high-speed spool position control device according to any one of claims 1 to 6, wherein the spool is a substantially equal area spool. 8. The high-speed spool position control device according to any one of claims 1 to 6, wherein the spool is a poppet-shaped spool. 9. High-speed spool position control according to any one of claims 1 to 8, wherein the spool is biased in one direction by a spring provided in the back pressure chamber. Device.