KR102083517B1 - Spool for flow control valve and a flow control valve using the spool - Google Patents

Abstract

The present invention relates to a flow control valve. The purpose of the present invention is to provide a flow control valve capable of preventing a leakage loss. According to an embodiment of the present invention, a spool of the flow control valve includes: a cylindrical spool body; a first land unit and a second land unit, which are individually formed at both ends of the spool body and have the diameter larger than the diameter of the spool body; and a third land unit formed between the first land unit and the second land unit in the spool body, and having a diameter becoming increased from the first land unit toward the second land unit. A first flow path is connected to a first space between the first land unit and the third land unit, and a second flow path is connected to a second space between the second land unit and the third land unit. When the spool moves toward the first land unit, an inclined side of the third land unit closes a gap between the first space and the second space. When the spool moves toward the second land unit, the first space and the second space are connected.

Description

Spool for flow control valve and flow control valve having same {Spool for flow control valve and a flow control valve using the spool}

The present invention relates to a spool used for a flow control valve and a flow control valve having the spool, and more particularly, to have a novel configuration to eliminate the leakage flow rate and to mitigate the impact due to the rapid flow increase when opening the valve. And a flow control valve having the same.

In general, industrial equipment such as excavators, cranes, forklifts, etc. have hydraulic actuators, such as cylinders for driving the equipment, such hydraulic actuators have a plurality of flow control valves for controlling the working fluid.

1 shows a conventional general flow control valve for driving a cylinder 30. The flow control valve includes a spool 20 that can be reciprocated from side to side within the valve housing 10. The spool 20 is composed of a plurality of land portions 21, 22, 23, 24 having a larger diameter than the plurality of spool bodies 25. When the spool 20 moves a predetermined distance to the left in the illustrated flow control valve, the first flow path 11 and the fifth flow path 15 are opened, and the fluid supplied from the pump 40 is the first flow path 11, The cylinder 30 is supplied to the cylinder 30 through the first internal space S1 and the third flow path 13, and the fluid in the cylinder 30 is the fourth flow path 14, the second internal space S2, and the fifth fluid. Return to the fluid storage tank 15 through the flow path (15). Also, if the spool 20 moves to the right, the fluid is supplied to the cylinder 30 through the second flow path 12 and the fluid of the cylinder 30 returns to the tank 15 through the fifth flow path 15. .

As described above, the conventional flow control valve has an advantage in that the fluid can be controlled in both directions, but there is a problem in that energy loss (pressure loss) and fluid leakage loss occur. For example, even when the spool 20 is opened finely to control the cylinder 30, a large pressure is applied to the internal space S1 or S2, but heat is generated because the flow rate is small as compared with high pressure. That is, high-pressure fluid energy is lost as heat. In addition, no matter how precise the machining, there is a micrometer-sized gap between the valve housing 10 and the spool 20, so there is a problem that fluid leaks through the gap even when the valve is turned off.

Patent Document 1: Korean Patent Publication No. 2009-0028216 (published March 18, 2009) Patent Document 2: Korean Patent Publication No. 1996-0001513 (published January 25, 1996)

The present invention has been made to solve the above problems, and an object of the present invention is to provide a flow control valve that prevents leakage loss by zeroing the amount of fluid leakage between the valve housing and the spool.

It is another object of the present invention to provide a flow control valve that solves the problem that the equipment is impacted due to rapid fluid inflow during valve opening, thereby improving valve responsiveness and equipment operability.

According to an embodiment of the present invention, a cylindrical inner space and a first flow path and a second flow path so as to slide in the longitudinal direction of the cylindrical shape in the valve housing and the valve housing formed on the side of the inner space; A flow control valve having a spool disposed therein, the spool comprising: a cylindrical spool body; First and second land portions each having a diameter larger than that of the spool body and formed at both ends of the spool body; And a third land portion formed between the first land portion and the second land portion in the spool body, the third land portion having a diameter gradually increasing from the first land portion to the second land portion. The first passage communicates with the first space between the first land portion and the third land portion, the second flow passage communicates with the second space between the second land portion and the third land portion, and the spool is in the first land portion direction. Move to the third land portion is inclined side closed between the first space and the second space, and when the spool moves in the direction of the second land portion is configured to communicate with the first space and the second space Start the flow control valve.

According to one embodiment of the present invention, a spool for a flow control valve, comprising: a cylindrical spool body; First and second land portions each having a diameter larger than that of the spool body and formed at both ends of the spool body; And a third land portion formed between the first land portion and the second land portion in the spool body, the diameter of which is gradually increased from the cylindrical portion having a diameter smaller than the first land portion and the cylindrical portion toward the second land portion. And a third land portion formed of an expansion portion, wherein the diameter expansion portion of the third land portion is disposed between the first land portion and the third land portion of the inner space when the spool is disposed in the inner space of the flow control valve. Disclosed is a spool for a flow control valve, configured to open and close a first space and a second space between the second land portion and the third land portion of the inner space.

According to an embodiment of the present invention, a cylindrical inner space and a first flow path and a second flow path so as to slide in the longitudinal direction of the cylindrical shape in the valve housing and the valve housing formed on the side of the inner space; A flow control valve having a spool disposed therein, the spool comprising: a cylindrical spool body; First and second land portions each having a diameter larger than that of the spool body and formed at both ends of the spool body; And a third land portion formed between the first land portion and the second land portion in the spool body, the diameter of the cylindrical portion having a smaller diameter than the first land portion and the diameter gradually increasing toward the second land portion from the cylindrical portion. And a third land portion formed of an expansion portion, wherein the first flow passage communicates with a first space between the first land portion and the third land portion, and the second flow passage is connected to the second land portion and the third land. Communicating with the second space between the portions, and when the spool moves in the direction of the first land portion, the inclined side of the diameter expansion portion of the third land portion closes between the first space and the second space and the spool is connected to the second space. Disclosed is a flow control valve configured to communicate with a first space and a second space as it moves in a land direction.

According to an embodiment of the present invention, a valve block having first to fourth flow control valves for driving a hydraulic actuator, wherein a first valve and a second valve of the first to fourth flow control valves are connected in series. And a third valve and a fourth valve are connected in series, a contact between the first valve and the second valve is connected to a piston head side space of the hydraulic actuator, and a contact between the third valve and the fourth valve is the hydraulic type. The valve block is connected to the piston rod side space of the actuator, wherein each of the first to fourth valves is constituted by the above-described flow control valve.

In addition, when the piston rod of the hydraulic actuator is projected at this time, by opening the first valve and the third valve and closing the second valve and the fourth valve, the fluid supplied to the valve block through the first valve through the piston Injecting into the head side space and returning the fluid in the piston rod side space to the fluid tank through the third valve, and retracting the piston rod, the first valve and the third valve is closed and the second valve and the fourth valve By opening, the fluid supplied to the valve block can be injected into the piston rod side space through the fourth valve and the fluid in the piston head side space can be returned to the fluid tank through the second valve.

According to an embodiment of the present invention, the land portion of the spool is configured to increase in diameter, and the inclined side of the land portion is configured to open and close the space inside the valve housing, so that the leakage of fluid between the valve housing and the spool is zero. Has the effect of eliminating losses.

According to one embodiment of the invention, the land portion of the spool consists of a cylindrical portion having a diameter slightly smaller than the inner diameter of the valve housing and a diameter expansion portion gradually increasing in diameter and forming at least one notch in the cylindrical portion when opening the valve Sudden fluid ingress can have the effect of preventing shock to the equipment and improving valve responsiveness and equipment operability.

1 illustrates a conventional valve for driving a cylinder;
2 and 3 are views illustrating a valve block composed of a flow control valve according to an embodiment of the present invention;
4 illustrates a control valve with a spool according to one embodiment;
5 is a view for explaining a flow rate change according to the spool displacement of the control valve of FIG.
6 illustrates a control valve with a spool according to an alternative embodiment;
7 is an enlarged cross-sectional view of a portion of the spool of the control valve of FIG. 6;
8 is an enlarged perspective view of a portion of a spool;
9 and 10 are views for explaining the flow rate change according to the spool displacement of the control valve of FIG.
11 illustrates a spool according to an alternative embodiment.

The above objects, other objects, features and advantages of the present invention will be readily understood through the following preferred embodiments associated with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the invention to those skilled in the art.

In the drawings of the present specification, the length, thickness, width, etc. of the components may be exaggerated for the effective description of the technical content.

In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, the words "comprise" and / or "comprising" do not exclude the presence or addition of one or more other elements.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In describing the specific embodiments below, various specific details are set forth in order to explain the invention in more detail and aid in understanding. However, one of ordinary skill in the art can understand that the present invention can be used without these various specific details. In some cases, it is mentioned in advance that parts of the invention which are commonly known in the description and which are not highly related to the invention are not described in order to avoid confusion in describing the invention.

2 and 3 show a valve block composed of a flow control valve according to an embodiment of the present invention. 2, the valve block according to an embodiment may be composed of four flow control valves (V1, V2, V3, V4) and these four flow control valves (V1, V2, V3, V4) It can be set to drive a hydraulic actuator such as the cylinder 30.

The cylinder 30 is composed of a piston assembly composed of a piston head Ph and a piston rod Pr, and two flow paths of the valve block are respectively located in the space A on the piston head Ph side and the piston rod Pr side. It is in communication with the space (B) of the, it is possible to reciprocate the piston assembly (in the drawing) up and down by supplying fluid to one of the two spaces.

For example, when the valve block is controlled to open the first valve V1 and the third valve V3 and close the second valve V2 and the fourth valve V4 as shown in FIG. 2, the pump 40 controls the valve. Fluid introduced into the block passes through the first valve V1 to the piston head side space A of the cylinder 30, and the piston assembly is lifted upward by the hydraulic pressure of the injected fluid. At this time, the fluid filled in the piston rod side space B passes through the third valve V3 and returns to the fluid tank 50.

3 shows a state when the piston assembly of the cylinder 30 coupled to the valve block of FIG. 2 is lowered. When the valve block is controlled to close the first valve V1 and the third valve V3 and open the second valve V2 and the fourth valve V4 as shown in FIG. 3, the fluid is pumped by the pump 40. Is injected into the piston rod side space B of the cylinder 30 through the fourth valve V4, and the piston assembly is lowered down by the hydraulic pressure of the injected fluid. The filled fluid passes through the second valve V2 and returns to the fluid tank 50.

As such, although the operation modes of moving the piston assembly of the cylinder 30 up and down using the valve block are illustrated in FIGS. 2 and 3 respectively, the valve block may operate in various various modes. For example, in FIGS. 2 and 3, only the case where the first valve V1 injects the fluid supplied from the pump 40 into the piston head side space A or closes the valve V1 is shown. The fluid discharged from the head side space A may be controlled to pass through the first valve V1.

A flow control valve according to an embodiment will now be described with reference to FIG. 4.

4, a flow control valve according to an embodiment includes a valve housing 100 and a spool 200 disposed in the valve housing 100.

The valve housing 100 has an inner cylindrical shape having a substantially cylindrical shape, and a first flow path 111 and a second flow path 112 are formed on the side of the inner space. In the illustrated embodiment, the first flow passage 111 may be connected to a pump 40 for supplying a fluid and the second flow passage 112 may be connected to a cylinder 30 applied to a load of, for example, an excavator. Alternatively, the first flow path 111 may be connected to the cylinder 30 and the second flow path 112 may be connected to the pump 40.

The illustrated flow control valve corresponds to each of the valves V1, V2, V3, V4 of the valve block of FIG. 2, and, for example, corresponds to the second valve V2 or the third valve V3. 111 may be connected to the storage tank 50 and the second flow path 112 may be configured to be connected to the cylinder 30. On the contrary, the first flow path 111 may be connected to the cylinder 30 and the second flow path 112 may be connected to the storage tank 50. ) May be connected to the storage tank (50).

The spool 200 is disposed in the valve housing 100 and is configured to slide reciprocally a predetermined distance in the longitudinal direction of the cylindrical inner space of the valve housing 100. For example, a spring 118 is interposed between the right end of the spool 200 and the inner surface of the valve housing 100, and although not illustrated, a pilot part may be installed at the left end of the spool 200. . The pilot portion has a piston (not shown) which moves left and right (on the drawing) by a solenoid coil or fluid, which can slide the left end side of the spool 200 to slide the spool 200 to the right. Since the operation control of the spool 200 by the pilot part is well known, a detailed description thereof will be omitted.

In the illustrated embodiment, the spool 200 includes a cylindrical spool body 201 having a predetermined diameter and first to third land portions 210, 220, and 230 which are larger than the spool body and are spaced apart from each other. can do. The spool body 201 and the first to third land portions 210, 220, 230 may be manufactured integrally, and in alternative embodiments, the body 201 and the land portions 210, 220, 230 may be separately manufactured and then combined.

In the illustrated embodiment, the first land portion 210 and the second land portion 220 are formed at both ends of the spool body 201, and the third land portion 230 is formed of the first land portion 210 and the first land portion 210. It is formed between two land portions 220.

The first flow path 111 of the valve housing 100 is positioned between the first land portion 210 and the third land portion 230 of the spool 200, and thus, the first land portion of the inner space of the valve housing 100 is located. The first space S1 and the first flow path 111 between the 210 and the third land part 230 communicate with each other. The second flow path 112 of the valve housing 100 is positioned between the third land portion 230 and the second land portion 220 of the spool 200, and thus, a third land of the inner space of the valve housing 100 is located. The second space S2 between the part 230 and the second land part 220 communicates with the second flow path 112.

The first land part 210 and the second land part 220 serve to guide the reciprocation of the spool 200. That is, while the spool 200 reciprocates in the inner space of the valve housing 100, the spool 200 guides the movement of the spool 200 such that the spool 200 does not deviate from the central axis of the inner space of the valve housing 100. To this end, in one embodiment, the diameter of the first land portion 210 may be configured to be equal to the inner diameter of the first space S1. In addition, the diameter of the second land portion 220 is configured to be the same as the inner diameter of the space in contact with the second land portion 220 in the second space (S2).

The third land portion 230 is configured to gradually increase in diameter from the first land portion 210 toward the second land portion 220 side (ie, toward the right side in the drawing). The maximum diameter of the third land portion 230 is larger than the diameter of the first land portion 210 or the inner diameter of the first space S1 surrounding the first land portion 210. In addition, the maximum diameter of the third land portion 230 is the same as or smaller than the inner diameter of the second space (S2).

As the spool 200 reciprocates from side to side, the third land part 230 of the spool 200 may open and close between the first flow path 111 and the second flow path 112. That is, when the spool 200 moves to the left side (that is, in the direction of the first land portion 210), one point P1 (hereinafter referred to as 'first point') on the inclined side surface of the third land portion 230 is The first flow path 111 and the first channel are blocked while the first space S1 and the second space S2 are blocked while being in contact with the edge Pe of the step portion separating the first space S1 and the second space S2. When the two flow paths 112 are closed and the spool 200 moves to the right (ie, in the direction of the second land part 220), the point P1 and the valve housing 100 of the inclined surface of the third land part 230 are moved. As the edge Pe of the inner space falls, the first flow path 111 and the second flow path 112 communicate with each other.

According to this configuration, the inclined side surface of the third land portion 230 blocks the first space S1 and the second space S2 while contacting the stepped edge Pe of the internal space of the valve housing 100. The amount of fluid leakage between the spaces S1 and S2 can be made zero.

5 is a view showing a flow rate change according to the spool displacement of the control valve of Figure 4, Figure 5 (a) is a point P1 of the third land portion 230 is in contact with the stepped corner Pe The first space S1 and the second space S2 are in a closed state, and FIG. 5B illustrates a state in which the spool 200 is moved to the right and has a left end point P2 of the third land portion 230. ) (Also referred to as 'second point') when it reaches the edge of the stepped part (Pe). 5C illustrates a change in flow rate between the first space S1 and the second space S2 according to the movement of the spool 200 in the right direction.

As shown in the drawing, when the point P1 of the inclined side surface of the third land portion 230 is in contact with the stepped edge Pe, the third land portion 230 is formed in the first and second spaces S1 and S2. The flow between the two spaces is zero because it is blocking the gap between them. As the spool 200 gradually moves to the right, the two spaces S1 and S2 gradually communicate with each other, until the spool 200 moves from (a) to (b) of FIG. 5 (that is, the third land). The sloped side of the third land portion 230 passes through the stepped edge Pe until the left end of the portion 230 (ie, the second point P2) reaches the stepped edge Pe. Therefore, the cross section communicating between the two spaces S1 and S2 is not large, and the cross section communicating between the two spaces S1 and S2 increases after the point (b) of FIG. 5. Therefore, as shown schematically in FIG. 5C, the flow rate increases immediately after the first point P1 of the third land portion is separated from the stepped edge Pe, and the second point P2 is the stepped edge Pe. As the flow rate passes through, the flow rate change characteristics are greatly increased.

6-8, a flow control valve according to an alternative embodiment will now be described. 6 is a schematic cross-sectional view of a control valve with a spool 300 according to an alternative embodiment, FIG. 7 is an enlarged cross-sectional view of a portion of the spool 300 of the control valve of FIG. 6, and FIG. 8 is a spool 300. An enlarged perspective view of a portion of the.

Referring to the drawings, a flow control valve according to an alternative embodiment includes a valve housing 100 and a spool 300 disposed within the valve housing 100. The valve housing 100 of FIG. 6 has the same or similar configuration and function as the valve housing 100 of FIG. 4, and thus a detailed description thereof will be omitted.

The spool 300 is disposed in the valve housing 100 and is configured to slide reciprocally a predetermined distance in the longitudinal direction of the cylindrical inner space of the valve housing 100. Springs 118 and / or pilot portions (not shown) may be disposed on both end sides of the spool 300 for the reciprocating motion of the spool 300. Since the configuration is well known in the art, description thereof will be omitted. .

In the illustrated embodiment, the spool 300 may include a cylindrical spool body 301 having a predetermined diameter and first to third land portions 310, 320, and 330 that have a larger diameter than the spool body and are spaced apart from each other. . The spool body 301 and the first to third land portions 310, 320, 330 may be manufactured integrally, and in alternative embodiments, the body 301 and the land portions 310, 320, 330 may be manufactured separately and then combined.

The first land part 310 and the second land part 320 are formed at both ends of the spool body 301, respectively, and the third land part 330 is the first land part 310 and the second land part 320. Formed between).

The first flow path 111 of the valve housing 100 is positioned between the first land portion 310 and the third land portion 330, and the first land portion 310 and the third land of the inner space of the valve housing 100 are located. The first space S1 and the first flow path 111 between the portions 330 communicate with each other. The second flow path 112 of the valve housing 100 is positioned between the third land portion 330 and the second land portion 320, and the third land portion 330 and the third land portion 330 of the inner space of the valve housing 100 are positioned. The second space S2 between the two land portions 320 communicates with the second flow path 112. In an embodiment, the diameter of the first land portion 310 may be configured to be equal to the inner diameter of the first space S1, and the diameter of the second land portion 320 may be the second land in the second space S2. It may be configured to be the same as the inner diameter of the space in contact with the part 320.

The third land part 330 may include a cylindrical part 331 which maintains a constant diameter and a diameter expanding part 332 which gradually increases in diameter. The cylindrical portion 331 is formed on the left side of the second land portion 330, that is, closer to the first land portion 310, and has a predetermined predetermined diameter.

The diameter of the cylindrical portion 331 is larger than the diameter of the spool body 301 and smaller than the inner diameter of the first space S1, and thus, the distance d between the cylindrical portion 331 and the inner diameter of the first space S1. This exists. This interval d serves to prevent a sudden increase in the flow rate between the two spaces S1, S2. In a preferred embodiment this spacing d may be from several to several hundred micrometers and may vary depending on the specific embodiment such as the size of the valve. In one embodiment, the ratio of the inner diameter of the valve housing 100 in contact with the first land portion 310 and the spacing d may be designed to be between about 100: 0.3 and 100: 0.5. For example, when the inner diameter of the valve housing 100 is 25mm, the interval d may be set to 0.1mm.

Cylindrical portion 331 may include one or more notches 335. As illustrated in FIGS. 7 and 8, the notch 335 may be formed on the surface of the cylindrical portion 331, but may be formed at the edge of the cylindrical portion 331 facing the first land portion 310.

The number of notches 335 formed in the cylindrical portion 331 is not limited. For example, two may be formed at 180 degree intervals based on the central axis of the spool 300 as shown, or alternatively, four may be formed at 90 degree intervals. Further, the length (length in the left and right directions in FIG. 7) and the depth (length in the vertical direction in FIG. 7) of each notch may be formed differently for each notch.

The diameter extension part 332 has a shape in which the diameter gradually increases from the cylindrical part 331 toward the second land part 320 side (ie, toward the right side in the drawing). The maximum diameter of the diameter expansion part 332 is larger than the diameter of the first land part 310 or the inner diameter of the first space S1 surrounding the first land part 310, and the inner diameter of the second space S2. Equal or less

For convenience of description, the main point of the third land part 330 will be defined with reference to FIG. 7. In FIG. 7, a point of contacting the edge Pe of the stepped portion of the inner space of the valve housing 100 among the inclined side surfaces of the inclined extension part 332 is called a first point P1, and The point where the inclined surface ends, that is, the connection point between the cylindrical portion 331 and the inclined extension portion 332 is called a second point P2. The end of the notch 335 of the cylindrical portion 331 is called the third point P3, and the left end of the third land portion 330, that is, the left end of the cylindrical portion 331 is the fourth point P4. This will be called.

As the spool 300 moves left and right, the third land part 330 of the spool 300 opens and closes between the first flow path 111 and the second flow path 112. That is, when the spool 300 moves to the left side (that is, in the direction of the first land part 310), the first point P1 of the inclined side surface of the inclined extension part 332 of the third land part 330 becomes the first point. The first space S1 and the second space S2 are blocked between the first space S1 and the second space S2 while contacting the edge Pe of the step portion that separates the space S1 and the second space S2. When 112 is closed and the spool 300 moves to the right (ie, in the direction of the second land portion 320), the first point P1 and the valve housing 100 of the inclined surface of the third land portion 330 are closed. As the stepped edge Pe of the inner space falls, the first flow path 111 and the second flow path 112 communicate with each other.

9 and 10 are views for explaining a change in flow rate according to the displacement of the spool of the control valve of FIG. 6, FIG. 9 shows the spool 300 gradually moving to the right in the drawing, and FIG. The flow rate change with the movement of) is shown schematically.

FIG. 9A illustrates a state in which the first space P1 of the third land portion 330 is in close contact with the stepped corner Pe, and thus the first space S1 and the second space S2 are blocked. 9 (b) is a state in which the spool 300 is moved to the right so that the second point P2 of the third land portion 330 is located at the stepped corner Pe, and FIG. 3 when the third point P3 of the land portion 330 reaches the edge Pe of the stepped portion, and FIG. 9D illustrates a fourth point P4 of the third land portion 330. It shows the state when it came to the secondary corner Pe.

In FIG. 9A, since the third land part 330 is in close contact with the stepped edge Pe and blocks between the two spaces S1 and S2, the flow rate is zero. Since the distance d between the cylindrical portion 331 of the third land portion 330 and the inner surface of the first space S1 is very fine between several to several hundred micrometers, the spool 300 is shown in FIG. The cross-section communicating with the spaces S1 and S2 gradually increases while passing through the (c) state, and also steps between the third point P3 and the fourth point P4 of the third land portion 330. Since the fluid passage area increases only by the cross-sectional area by the part 335, the two spaces S1 and S2 during the movement of the spool 300 from (a) to (d) of FIG. 9 as shown in the flow rate change graph of FIG. The flow rate passing through) does not increase rapidly, but shows a gradually changing flow rate step by step.

Therefore, compared to the embodiment of Figure 4, the embodiment of Figure 6 can reduce the impact applied to the cylinder 30 when switching the valve on / off, and also because the flow rate increases nearly linear with the movement of the spool 300 It has the effect of improving valve responsiveness and equipment operability.

11 shows an alternative embodiment of the third land portion 330 of the spool 300. In FIG. 11A, the third land portion 330 includes a cylindrical portion 331 and a diameter expanding portion 332 and includes one or more stepped notches 336 in the cylindrical portion 331. The stepped notch 336 is a step in which the bottom surface of the notch 336 is stepped, and the bottom distance of each step of the notch 336 from the central axis of the spool 300 is different. In FIG. 11B, the third land portion 330 includes a notch portion 337 formed in a triangular cross section in the cylindrical portion 331. In other words, the notch 337 has a triangular shape when viewed from the side of the spool 300.

According to the embodiment of FIG. 11 as described above, when the spool 300 slides toward the second land part 320, the area of communication between the two spaces S1 and S2 due to the notches 336 and 337 is gradually increased. Accordingly, the flow rate change increases stepwise or more gently than shown in Fig. 10, which further reduces the impact on the apparatus and further improves valve response and equipment operability.

As will be appreciated by those skilled in the art to which the present invention pertains, various modifications and variations are possible from the description of this specification. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below but also by the equivalents of the claims.

100: valve housing
200, 300: Spool
201, 301: spool body
210, 220, 230, 310, 320, 330: Land part
331: cylindrical portion
332 diameter expansion part
335, 336, 337: notch

Claims (15)

delete delete delete Spooler for flow control valve,
A cylindrical spool body 301;
A first land portion 310 and a second land portion 320 formed at both ends of the spool body and having a diameter larger than that of the spool body; And
A third land portion 330 formed between the first land portion and the second land portion in the spool body, the cylindrical portion 331 having a smaller diameter than the first land portion and the second land portion in the cylindrical portion 331. And a third land portion 330 made up of a diameter expanding portion 332 having a maximum diameter larger than the diameter of the first land portion and gradually increasing toward the side.
When the spool is disposed in the internal space of the flow control valve, the diameter-expanded portion 332 of the third land portion is the first between the first land portion 310 and the third land portion 330 of the internal space. It is configured to open and close between the space (S1) and the second space (S2) between the second land portion 320 and the third land portion 330 of the internal space,
At least one notch 335 is formed at an edge of the cylindrical portion 331 facing the first land portion side,
The diameter of the cylindrical portion 331 is smaller than the inner diameter of the valve housing 100 surrounding the cylindrical portion 331, and between the inner diameter of the valve housing 100 and the cylindrical portion 331 and the inner diameter By setting the ratio of the interval d to a value between 100: 0.3 and 100: 0.5, the two spaces S1 and S2 when the spool opens between the first space S1 and the second space S2 Spool for flow control valve, characterized in that configured to prevent a sudden increase in flow rate. delete The method of claim 4, wherein
The diameter of the first land portion 310 is the same as the inner diameter of the first space (S1), the maximum diameter of the diameter expansion portion 332 is characterized in that the flow rate, characterized in that less than or equal to the inner diameter of the second space (S2) Spool for control valve. delete The method of claim 4, wherein
And the notch (335) is formed stepwise so as to have a plurality of notched surfaces having different distances from the central axis of the spool. It has a cylindrical inner space and the first flow path 111 and the second flow path 112 so as to slide in the longitudinal direction of the cylindrical shape in the valve housing 100 and the valve housing formed on the side of the inner space. A flow control valve having a spool 300 disposed therein, wherein the spool 300 includes:
A cylindrical spool body 301;
A first land portion 310 and a second land portion 320 formed at both ends of the spool body and having a diameter larger than that of the spool body; And
A third land portion 330 formed between the first land portion and the second land portion in the spool body, the cylindrical portion 331 having a smaller diameter than the first land portion and the second land portion in the cylindrical portion 331. And a third land portion 330 made up of a diameter expanding portion 332 having a maximum diameter larger than the diameter of the first land portion and gradually increasing toward the side.
The first flow path 111 communicates with the first space S1 between the first land part 310 and the third land part 330, and the second flow path 112 is connected to the second land part 320. And the second space S2 between the third land part 330,
When the spool moves in the direction of the first land portion, the inclined side surface of the diameter expansion portion of the third land portion 330 closes between the first space S1 and the second space S2, and the spool is connected to the second land portion. The first space (S1) and the second space (S2) is configured to communicate with each other in the direction of the land portion,
At least one notch 335 is formed at an edge of the cylindrical portion 331 facing the first land portion side,
The diameter of the cylindrical portion 331 is smaller than the inner diameter of the valve housing 100 surrounding the cylindrical portion 331, and between the inner diameter of the valve housing 100 and the cylindrical portion 331 and the inner diameter By setting the ratio of the interval d to a value between 100: 0.3 and 100: 0.5, the two spaces S1 and S2 when the spool communicates between the first space S1 and the second space S2. Flow control valve, characterized in that configured to prevent a sudden increase in flow between. The method of claim 9,
The diameter of the first land portion is equal to the diameter of the first space (S1), the maximum diameter of the diameter expansion portion (332) is the flow rate control valve, characterized in that the second space (S2) is equal to or smaller than the inner diameter. The method of claim 10,
The flow control valve, characterized in that the interval (d) is several to several hundred micrometers. delete The method of claim 9,
And the notch (335) is formed stepwise so as to have a plurality of notch surfaces having different distances from the central axis of the spool. A valve block having first to fourth flow control valves for driving a hydraulic actuator,
Among the first to fourth flow control valves, a first valve V1 and a second valve V2 are connected in series, and a third valve V3 and a fourth valve V4 are connected in series.
The contact point between the first valve V1 and the second valve V2 is connected to the piston head side space A of the hydraulic actuator, and the contact point between the third valve V3 and the fourth valve V4 is Connected to the piston rod side space B of the hydraulic actuator,
Each of the first to fourth valves comprises a flow control valve of any one of claims 9 to 11 and 13, characterized in that the valve block. delete

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