JP3224266B2 - Operating valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an operation valve whose output can be controlled in accordance with the operation amount of an operation lever.

2. Description of the Related Art The conventional example shown in FIG. 3 incorporates four valve mechanisms in the body 1, but only two valve mechanisms appear at the sectional position in FIG. However, since the configuration of each of these valve mechanisms is the same, the following description will be given with the same reference numerals given to common components of the two valve mechanisms shown in the drawings.

[0002] A body 1 has a spring chamber 2 and a plunger insertion hole 3 formed in series. A guide member 4 is fixed to the upper end of the spring chamber 2, and a push rod 5 is slidably inserted into the guide member 4. The push rod 5 is provided with a spring guide 5a, and the spring guide 5a is located in the spring chamber 2. Spring guide 5a thus configured
, A pair of spring receivers 6 and 7 are slidably provided, and a spring 8 is interposed between the spring receivers 6 and 7. When the spring receivers 6 and 7 are at the positions shown in the drawing by the action of the spring 8, the push rod 5 projects from the guide member 4 by the maximum amount.

[0003] A plunger 9 is inserted into the plunger insertion hole 3.
Is slidably inserted. The upper end of the plunger 9 is projected into the spring chamber 2 and the cylindrical member 10 is fixed to the projected portion. The cylindrical member 10 is brought into contact with the lower spring receiver 7 and
The tip of the spring guide 5a can enter the inside. Further, a weak spring 11 is also interposed between the upper end flange 10a of the cylindrical member 10 and the bottom of the spring chamber 2. The plunger 9 thus configured has a port 12
Is formed. This port 12 is always in communication with an output port 14 that is continuous with the plunger insertion hole 3 through a through hole 13 formed along the axis of the plunger 9.

When the plunger 9 is in the normal position shown in the figure, the port 12 is displaced from the pump port 15 formed in the body 1 and the communication is cut off. In the figure, reference numeral 16 denotes an operation lever, whose lower end is rotatably mounted on the body 1 side, and whose flange 17 pushes the push rod 5 in accordance with the rotation direction of the operation lever 16. Now, when the operation lever 16 is rotated clockwise in the drawing, the right push rod 5 is
Is pushed in against. Accordingly, the plunger 9 also moves so that the port 12 and the pump port 15 are wrapped, and the discharge oil of the pump P flows out of the output port 14 through the hole 13. Output port 1 at this time
The pressure on the fourth side is determined by the amount of wrap between the port 12 and the pump port 15 and the flow rate flowing therethrough.

In the plunger 9, the insertion hole 3
Are inserted into a large-diameter portion 9a and a small-diameter portion 9b, and the lower end of the small-diameter portion 9b faces the output port 14 as a main pressure receiving surface 18. The boundary between the large-diameter portion 9a and the small-diameter portion 9b is defined as a sub-pressure receiving surface 19, which faces the pilot chamber 20. This pilot room 20
, A pilot pressure is guided from a pilot port 21 formed in the body 1.

When the operating lever 16 is rotated clockwise as described above, the spring 8 is deflected while pushing the right push rod 5, and the plunger 9 is pushed down. When the plunger 9 moves in this manner, the port 12 and the pump port 15 overlap, and the discharge oil of the pump P flows out of the output port 14. The pressure of the output port 14 at this time acts on the main pressure receiving surface 18 to push up the plunger 9 against the spring 8. Therefore, the plunger 9 stops at a position where the pressure on the output port 14 side acting on the main pressure receiving surface 18 and the spring force of the spring 8 bent by the pressing force of the push rod 5 are balanced. The lap amount is determined. In other words, the pressure proportional to the operation amount of the operation lever 16 is
Output can be made from the output port 14.

The output port 1 is connected to the pilot chamber 20.
When the pilot pressure irrelevant to the side 4 is introduced, the auxiliary pressure receiving surface 19
Since this pilot pressure acts on the plunger 9, the force for pushing up the plunger 9 increases in combination with the pressure action on the main pressure receiving surface 18 side. Therefore, even when the operation lever 16 is rotated by the same angle, the pressure P _i output from the output port 14 is different between when the pilot pressure is introduced into the pilot chamber 20 and when it is not. FIG. 4 shows the output characteristics. 4 shows the characteristics when the pilot pressure is not acting on the sub-pressure receiving surface 19 and the straight line b shows the characteristics when the pilot pressure is acting. As is apparent from this figure, when the pilot pressure is applied, the pressure P _i in the output port 14 is relatively lower than the spring force f of the spring 8, that is, the operation amount of the operation lever 16. I understand. Then, it can be seen that the characteristic change from the straight line a to b at this time is such that the straight line b moves in parallel by the pressure of the pilot chamber 20.

[0008]

In the conventional operating valve as described above, when pressure is applied to the pilot chamber 20, the straight lines a and b move in parallel, so that it is apparent from FIG. However, there is a problem that the effective operation range is narrowed. An object of the present invention is to provide an operation valve that changes control characteristics without narrowing an effective operation range.

[0009]

According to the present invention, a plurality of plungers are slidably provided on a body, and a spring is interposed between the plunger and a push rod whose tip projects from the body. The other end faces the output port of the body, and the opening of the pump port of the body is controlled in accordance with the amount of movement of the plunger. By rotating the plunger while pushing the push rod, the plunger is moved, and while the spring force of the spring acting on the plunger and the pressure on the output port side are balanced,
It is based on an operating valve that controls the opening of the pump port. While assuming the above-described operation valve, the plunger is formed with a main pressure receiving surface on which the pressure on the output port acts and a sub-pressure receiving surface on which the pressure of the pilot chamber communicated with the output port acts. Is characterized in that a control valve for connecting or disconnecting the output port and the pilot chamber is provided.

[0010]

Since the present invention is constructed as described above, if the control valve is closed, the pressure on the output port acts only on the main pressure receiving surface. However, when the control valve is opened, the pressure on the output port side is guided to the pilot chamber and acts on the sub-pressure receiving surface. The pilot pressure acting on the sub-pressure receiving surface is equal to the pressure acting on the main pressure-receiving surface, and is variable. Therefore, when the pilot pressure is acting and when it is not acting, only the gain is different. , Does not affect the operation range.

[0011]

According to the operating valve of the present invention, the control characteristics can be changed without affecting the operating range, so that a wide range of control is possible. Therefore, various controls can be performed on the actuator or the like that is the object of pressure control according to the environmental conditions.

[0012]

The embodiment shown in FIG. 1 is different from the prior art in that the pilot chamber 20 is communicated with the output port 14 and a control valve V is provided in the communicating process. The same is true. Therefore, the same components as those in the related art will be described using the same reference numerals, and details thereof will be omitted. The control valve V includes a spool 23 inserted into a spool hole 22 of the body 1 and a solenoid 24 for moving the spool 23 as main components. The spool 23 applies a spring force of a spring 25 to one end thereof, and the spool 23
The other end is always in contact with the rod 26 of the soleinoid 24.

[0013] The land 23 is attached to the spool 23 in this manner.
An annular groove 23c is formed between a and 23b. The passage 27 that communicates with the output port 14 and the passage 28 that communicates with the pilot chamber 20 communicate with each other or are interrupted depending on the position of the spool 23.
That is, in the illustrated state where the solenoid 24 is excited and the spool 23 is pressed against the spring 25, the passage 27 is closed by the land 23a, so that the communication between the output port 14 and the pilot chamber 20 is cut off. When the solenoid 24 is de-energized, the spool 23
With the force of 5, it moves downward in the drawing. Therefore, both passages 2
7 and 28 communicate with each other through the annular groove 23c, and the output port 14 and the pilot chamber 20 also communicate with each other.

Next, the operation of this embodiment will be described. Now, the solenoid 24 of the control valve V is excited and the spool 2
3, the communication between the output port 14 and the pilot chamber 20 is cut off, and the pilot chamber 20 is opened to the tank through the passage 30. By operating the operating lever 16 in this state, the spool 23 at a position where the acting force of the pressure P _i of the spring force f and the output port 14 side at that time are balanced
Stops and the substantial opening of the pump port 15 is controlled. The line a in FIG. 2 shows the control characteristics at this time. Next, when the solenoid 24 of the control valve V is de-energized and the spool 23 is moved downward in the drawing, the passage 30
The communication with the tank at the pressure chamber is interrupted and the output port 14 is connected to the pilot chamber 2 via the passage 27 → the annular groove 23c → the passage 28.
Communicate with 0. Therefore, the pressure on the output port 14 side is guided to the pilot chamber 20, which also acts on the auxiliary pressure receiving surface 19. Since the pilot pressure guided to the pilot chamber 20 changes according to the operation amount of the operation lever 16 and the pressure on the output port 14 side, the control characteristic at that time is as shown in FIG.
As shown by the straight line b.

Since the pilot pressure in the pilot chamber 20 changes as described above, only the slope of the straight line b changes with respect to the straight line a. Therefore, in this embodiment, there is no characteristic change such that the straight lines a and b move in parallel as in the related art. Therefore, according to this embodiment, the effective operation range of the operation lever does not become narrow.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a graph showing control characteristics.

FIG. 3 is a sectional view of a conventional operation valve.

FIG. 4 is a graph showing a conventional control characteristic.

[Code] 1 Body 5 Push rod 8 Compression spring 9 Plunger 14 Output port 15 Pump port 16 Operating lever 18 Main pressure receiving surface 19 Secondary pressure receiving surface 20 Spring chamber V Control valve 27 Passage 28 Passage

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F15B 13/042 F16K 31/44

Claims (1)

(57) [Claims] A plurality of plungers are slidably provided on a body, and a spring is interposed between the plungers and a push rod having a tip protruding from the body, while the other end of the plungers is connected to an output port of the body. Side, and the opening of the pump port of the body is controlled in accordance with the amount of movement of the plunger. The operating valve for controlling the opening degree of the pump port while pushing the rod to deflect the spring to move the plunger and balance the spring force of the spring acting on the plunger and the pressure on the output port side, wherein the plunger Is the main pressure receiving surface on which the pressure at the output port acts, and the pressure of the pilot chamber connected to the output port. A control valve is provided in the flow path process for communicating the output port with the pilot chamber while forming a sub-pressure receiving surface on which the output port operates, and for communicating or shutting off the communication between the output port and the pilot chamber. Operating valve characterized by the following.