KR102149963B1 - Spool with improved workability and precise controllability and a flow control valve using the spool - Google Patents

Abstract

According to an embodiment of the present invention, a valve body having a cylindrical inner space, the first flow path 111 and the second flow path 112 formed on the side of the inner space, and the length of the cylindrical shape in the valve body A flow control valve having a spool 300 disposed to be slid in a direction, the spool 300 comprising: a spool rod 301 having a first end and a second end having a cylindrical shape; A first land portion 310 having a larger diameter than the spool rod and formed close to the first end portion; A second land portion 320 having a larger diameter than the first land portion and spaced apart from the second end portion; And a third land portion 330 having a multi-diameter formed between the first land portion and the second land portion, wherein the third land portion 330 moves from the first end side to the second end side. Disclosed is a flow control valve comprising a small diameter portion 331, an inclined portion 332, and a large diameter portion 333 formed in sequence.

Description

Spool with improved workability and precise controllability and a flow control valve using the spool}

The present invention relates to a spool used in a flow control valve and a flow control valve having the spool, and more particularly, to a spool having improved processing ease and control precision, 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, and such hydraulic actuators are provided with a plurality of flow control valves for controlling working fluid.

1 shows a conventional general flow control valve for driving the cylinder 70. In the flow control valve, a sleeve 20 is attached to the inside of the valve housing 10 and a spool 30 reciprocating left and right is inserted in the inner space of the sleeve 20. The spool 30 is composed of a spool rod 31 corresponding to the body of the spool and a plurality of land portions 32 and 33 having a larger diameter than the spool rod 31.

When the valve is opened, for example, when the spool 30 slides to the right by a piston (not shown) in the pilot part, the first flow path 11 and the second flow path 12 are opened, and the fluid supplied from the tank 60 Is supplied to the cylinder 70 through the first and second flow paths 11 and 12. When the valve is closed, when the piston of the pilot part returns to the left, the spool 30 slides to the left by the elastic force of the spring 17 to return to the original position.

However, in such a conventional valve, even when the spool 30 is slightly opened, a large amount of fluid flows through the gap between the second land part 33 and the sleeve 20, so that the amount of fluid change when the valve is turned on/off becomes rapid. There is a problem that valve control is not easy.

In addition, when manufacturing a valve, the more the area where the spool 30 and the inner space of the valve are in contact, the more difficult it is to manufacture.In the case of a conventional valve, the left and/or right ends of the plurality of land portions 32 and 33 and the spool rod 31 Since the spool 30 and the inner space of the valve are in contact with at least 3 or 4 places on the back, precision processing within a few micrometers is required to process the spool while maintaining the straightness and parallelism at all of these 3 or 4 places. The processing cost has risen.

Moreover, since it is very difficult to directly process the valve body with such precision, a separate sleeve 20 has been processed. That is, the valve was manufactured by processing the sleeve 20, which is relatively easy to process compared to the valve housing 10, and fastening it inside the valve housing 10 and inserting the spool 30 into the inner space of the sleeve 20. As a result, there is a problem that the valve volume and cost increase because parts are added.

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

The present invention is to solve the above problems, and provides a spool that prevents an impact on equipment due to a sudden change in fluid when the valve is turned on/off, and improves valve responsiveness and equipment operability, and a flow control valve having the same. do.

According to an embodiment of the present invention, the number of areas in which the spool and the inner surface of the valve body are in contact is minimized to improve the processing ease of the valve body and the spool, and by eliminating the need for a sleeve, the valve volume and manufacturing cost can be reduced. It provides a spool and a flow control valve having the same.

In addition, according to an embodiment of the present invention, by configuring a spool-spring integrated spool in which a spring is attached to a spool, a spool capable of preventing the spring from being incorrectly fastened when manufacturing a valve, and making all spools have the same force-displacement characteristics It provides a flow control valve having this.

According to an embodiment of the present invention, a valve body having a cylindrical inner space, the first flow path 111 and the second flow path 112 formed on the side of the inner space, and the length of the cylindrical shape in the valve body A flow control valve having a spool 300 disposed to be slid in a direction, the spool 300 comprising: a spool rod 301 having a first end and a second end having a cylindrical shape; A first land portion 310 having a larger diameter than the spool rod and formed close to the first end portion; A second land portion 320 having a larger diameter than the first land portion and spaced apart from the second end portion; And a third land portion 330 having a multi-diameter formed between the first land portion and the second land portion, wherein the third land portion 330 moves from the first end side to the second end side. A small diameter portion 331, an inclined portion 332, and a large diameter portion 333 formed in sequence are provided, and the small diameter portion 331 has a first diameter smaller than that of the first land portion, and the large diameter portion 333 ) Is larger than the first land portion, but has a second diameter equal to or smaller than the second land portion, and the inclined portion 332 is interposed between the small-diameter portion and the large-diameter portion to have a diameter from the first diameter to the second diameter. Is configured to increase gradually, and when the spool moves toward the first end, the inclined side surface of the inclined portion 332 of the third land portion contacts the first step portion of the inner space of the valve body, and the first space And the second space is closed, and the first space and the second space are in communication with each other when the spool moves toward the second end.

According to an embodiment of the present invention, there is provided a spool for a flow control valve, comprising: a spool rod 401 having a cylindrical shape and having a first end and a second end; A first land portion 410 having a larger diameter than the spool rod and formed at the first end portion; A second land portion 420 having a larger diameter than the first land portion and spaced apart from the second end portion; And a third land portion 430 having a multi-diameter formed between the first land portion and the second land portion, wherein the third land portion 430 moves from the first end side to the second end side. A small diameter portion 431, an inclined portion 432, and a large diameter portion 433 formed in sequence are provided, and the small diameter portion 431 has a first diameter smaller than that of the first land portion, and the large diameter portion 433 ) Is larger than the first land portion, but has a second diameter equal to or smaller than the second land portion, and the inclined portion 432 is interposed between the small-diameter portion and the large-diameter portion to have a diameter from the first diameter to the second diameter. Disclosed is a spool for a flow control valve, characterized in that it is configured to increase gradually.

According to an embodiment of the present invention, there is provided a flow control valve, comprising: a spool for the flow control valve; It has a cylindrical inner space for accommodating the spool, and includes a first flow path 211 and a second flow path 212 formed on the side of the internal space, and a through hole 213 formed in the direction toward the first end. Valve body 210; And a sliding block 220 disposed to be slidably fitted to the through hole 213.

According to an embodiment of the present invention, the land portion of the spool is composed of a cylindrical portion having a diameter smaller than the inner diameter of the valve body and a diameter expansion portion gradually increasing, and forming one or more notches in the cylindrical portion when the valve is opened. It may have the effect of preventing an impact on the equipment due to rapid fluid inflow and improving valve responsiveness and equipment operability.

According to an embodiment of the present invention, by minimizing the number of areas in which the spool and the inner surface of the valve body are in contact, the ease of processing when manufacturing the valve body and the spool is improved, and the need for a sleeve is eliminated to reduce the overall valve volume and manufacturing cost. It can have an effect.

According to an embodiment of the present invention, the spring is attached to the spool to make the spool integrally, so that when the spring is fastened, the operator can check the contraction degree or state of the spring and manufacture, so that all spools have the same force-displacement of the spring. It can be made to have characteristics.

1 is a view illustrating a conventional valve structure;
2 is a diagram illustrating a spool according to a first embodiment of the present invention and a flow control valve having the same;
3 is a view illustrating a spool according to a second embodiment of the present invention and a flow control valve having the same;
4 is a diagram illustrating a sliding block according to an embodiment;
5 and 6 are views for explaining a coupling structure between a spool and a spring according to an embodiment;
7 is a view for explaining the effect of the coupling structure between the spool and the spring according to an embodiment.

The above objects, other objects, features, and advantages of the present invention will be easily understood through the following preferred embodiments related to 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 disclosed content may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

In the drawings of the present specification, numerical values such as length, thickness, and width of components may be exaggerated for effective description of technical content.

In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used in the specification, "comprise" and/or "comprising" does not exclude the presence or addition of one or more other components.

Hereinafter, the present invention will be described in detail with reference to the drawings. In describing the specific embodiments below, various specific contents have been prepared to more specifically describe the invention and to aid understanding. However, readers who have knowledge in this field to the extent that they can understand the present invention can recognize that it can be used without these various specific contents. In some cases, it should be mentioned in advance that parts that are commonly known in describing the invention and are not significantly related to the invention are not described in order to avoid confusion in describing the invention.

2 shows a spool and a flow control valve having the same according to the first embodiment of the present invention.

Referring to the drawings, a flow control valve according to an embodiment includes a valve body 100 and a spool 300 disposed in the valve body 100.

In the illustrated embodiment, the valve body 100 is composed of a housing 110 and a sleeve 120 coupled to an inner surface of the housing 110, and slides while the spool 300 contacts the inner surface of the sleeve 120. I can. However, in an alternative embodiment, the sleeve 120 may be omitted, and in this case, the spool 300 is configured to slide while directly in contact with the inner surface of the housing 110.

The valve body 100 has a substantially cylindrical inner space, and a first flow path 111 and a second flow path 112 are formed on side surfaces of the internal space. In the illustrated embodiment, the first flow path 111 may be connected to the tank 60 for supplying fluid, and the second flow path 112 may be connected to a cylinder 70 applied to a load such as an excavator. Alternatively, the first flow path 111 may be connected to the cylinder 70 and the second flow path 112 may be connected to the tank 60.

The spool 300 is disposed within the valve body 100 and is configured to slide and reciprocate a predetermined distance in the longitudinal direction of the cylindrical inner space of the valve body 100. For example, a spring 117 is interposed between the right end of the spool 300 and the inner surface of the valve body 100, and although not shown in the drawing, a pilot part may be installed at the left end of the spool 300. have. The pilot unit includes a piston (not shown) that moves left and right (not shown) by a solenoid coil or fluid (in the drawing), and the piston pushes the left end side of the spool 300 to slide the spool 300 to the right. Alternatively, a high hydraulic pressure generated by the pilot portion may be applied to the left end of the spool 300 so that the spool 300 may slide to the right. The control of the operation of the spool 300 by the pilot portion and the spring 117 is a known technique, and thus a description thereof will be omitted.

In one embodiment, the valve body 100 includes one or more internal flow paths so that the fluid filled in the inner space of the valve body 100 does not interfere with the left and right sliding movement of the spool 300. For example, in the illustrated embodiment, the fluid in the area S2 between the first end side of the spool rod 301 and the first land part 310 and the area S4 between the second end side and the second land part 320 The inner flow path 115 is formed in the valve housing 110 so that the fluid filled in) can move freely, and the through holes 121 and 122 communicating with the internal flow path 115 are also formed in the sleeve 120.

In the illustrated embodiment, the spool 300 has a larger diameter than the cylinder-shaped spool rod 301 and the spool rod 301 of a predetermined diameter, and includes first to third land portions 310, 320 and 330 spaced apart from each other. can do. The spool rod 301 and the first to third land portions 310, 320, and 330 may be manufactured integrally, and in an alternative embodiment, the spool rod 301 and the land portions 310, 320 and 330 may be individually manufactured and then combined. .

The spool rod 301 may have a cylinder shape as a body portion of the spool 300. The spool rod 301 may have a constant diameter over the entire length and may have two or more diameters.

In one embodiment, a first land portion 310 and a second land portion 320 are formed on the left and right sides of the spool rod 301, respectively. The first land portion 310 is formed close to the first end (left end in the drawing) of the spool rod 301 and has a larger diameter than the spool rod 301. The second land portion 320 is formed on a side close to the second end (right end in the drawing) of the spool rod 301 and has a larger diameter than the spool rod 301.

Each of the first land part 310 and the second land part 320 is the same as the inner diameter of the valve body 100 surrounding each of them, so that the first and second land parts 310 and 320 In a state in close contact with the inner surface, the spool 300 may slide in the longitudinal direction.

The third land portion 330 is formed between the first land portion 310 and the second land portion 320. When the spool 300 is inserted into the valve body 100, the first flow path 111 of the valve body 100 is located between the first land part 310 and the third land part 330 as shown, The second flow path 112 of the valve body 100 is positioned between the third land part 330 and the second land part 320. Therefore, the first flow path 111 communicates with the space S3 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 third land part. It communicates with the space between the parts 330.

In one embodiment, the third land portion 330 is a multi-diameter land portion. In the illustrated embodiment, the third land portion 330 has a small diameter portion 331, an inclined portion 332 formed sequentially from the first end side to the second end side (ie, from left to right in the drawing), and It includes a large diameter portion 333.

The small-diameter portion 331 has a first diameter smaller than the first land portion 310, and the large-diameter portion 333 is larger than the first land portion 310, but has a second diameter equal to or smaller than the second land portion 320 Have. The inclined portion 332 is interposed between the small-diameter portion 331 and the large-diameter portion 333 so that the diameter gradually increases from the first diameter to the second diameter.

The diameter of the small-diameter portion 331 (that is, the first diameter) is larger than the diameter of the spool rod 301 but is slightly smaller than the diameter of the inner surface of the valve body 100 surrounding the small-diameter portion 331. That is, the small diameter portion 331 does not contact the inner surface of the sleeve 120 surrounding it, and a predetermined gap exists between the small diameter portion 331 and the inner surface of the sleeve 120 surrounding the small diameter portion 331. This interval serves to prevent a rapid increase in the flow rate between the two flow paths when the two flow paths 111 and 112 communicate with each other by the movement of the spool 300. This interval may vary depending on the size of the entire valve or the size of the spool 300, and may be between several micrometers and hundreds of micrometers. In one embodiment, for example, when the inner diameter of the sleeve 120 surrounding the small-diameter portion 331 is 26 mm, this interval may be set to 0.1 mm.

The small diameter portion 331 may include one or more notches 335. The notch 335 may be formed on the surface of the small diameter portion 331 and may be formed at the edge of the small diameter portion 331 facing the first land portion 310. The notch 335 may further prevent a rapid increase in the flow rate between the two flow paths 111 and 112.

The inclined portion 332 is integrally extended in the direction toward the second end of the small diameter portion 331. The inclined portion 332 is configured to have an inclined surface by gradually increasing in diameter from the small-diameter portion 331 toward the large-diameter portion 333. In the direction toward the second end of the inclined portion 332, a large diameter portion 333 is integrally formed to extend. The large diameter portion 333 has a second diameter larger than the diameter of the first land portion 310. In one embodiment, the large diameter portion 333 and the second land portion 320 may have the same diameter.

Since the large-diameter portion 333 has a larger diameter than the small-diameter portion 331, the inner inner diameter of the sleeve 120 surrounding the large-diameter portion 333 is also larger than the inner inner diameter surrounding the small-diameter portion 331, and thus as shown The sleeve 120 is also provided with a stepped portion.

With this configuration, the inclined portion 332 comes into close contact with or away from the step portion of the sleeve 120 due to the sliding movement of the spool 300, thereby performing a valve opening/closing operation. That is, when the spool 300 moves to the left, the inclined surface of the inclined portion 332 contacts the stepped portion of the sleeve 120 and the first flow path 111 and the second flow path 112 are closed, and the spool 300 is closed. When moving to the right, the inclined surface of the inclined portion 332 is separated from the stepped portion of the sleeve 120 so that the first flow path 111 and the second flow path 112 communicate.

At this time, according to the configuration of the present invention, it is possible to prevent rapid fluctuations in the flow rate when switching the opening/closing of the first flow path 111 and the second flow path 112. That is, the spacing between the small diameter portion 331 of the third land portion 330 and the inner diameter of the sleeve 120 surrounding the same is designed to be very fine in several to several hundred micrometers, and a notch 335 is formed in the small diameter portion 331. By forming, while moving in the right direction of the spool 300, the flow rate passing between the two flow paths 111 and 112 does not increase rapidly, but exhibits a flow rate change characteristic that gradually increases gradually. Therefore, compared to the prior art, there is an advantage of improving valve responsiveness and equipment operability and reducing the impact applied to the cylinder 70 when the valve is switched on/off.

3 shows a spool according to a second embodiment of the present invention and a flow control valve having the same.

Referring to the drawings, the flow control valve according to the second embodiment includes a valve body 210 and a spool 400 disposed in an inner space of the valve body 100.

In the illustrated second embodiment, a separate sleeve (eg, 120 in FIG. 2) is not required in the valve body 210, and the spool 400 may be placed in direct contact with the valve body 210. However, a sleeve may be coupled within the valve body 210 in an alternative embodiment.

The valve body 210 has a substantially cylindrical inner space, and a first flow path 211 and a second flow path 212 are formed on side surfaces of the internal space. In one embodiment, the first flow path 211 may be connected to the tank 60 supplying the fluid, and the second flow path 212 may be connected to the cylinder 70 applied to a load such as an excavator.

A through hole 213 communicating with the outside is formed on the side of the first end (left end in the drawing) of the valve body 210, and a sliding block 220 is inserted in the through hole 213 in a slidable state. have. A cover member 230 is coupled to the left side of the through hole 213 to surround the through hole 213 and seal it from the outside. A pilot portion (not shown) may be coupled to the left side of the cover member 230, for example. The piston (not shown) of the pilot part passes through the through hole 231 of the cover member 230 to push the sliding member 220 and the sliding member 220 pushes the spool 400 to move the spool 400 to the right. Can be slid.

The spool 400 is cylindrical in shape and has a larger diameter than the spool rod 401 and the spool rod 401 having a first end (left end in the drawing) and a second end (right end in the drawing), and are spaced apart from each other. First to third land portions 410, 420, and 430 may be provided.

The first land portion 410 is formed at the first end of the spool rod 401 and has a larger diameter than the spool rod 401. The second land portion 420 is formed on a side close to the second end of the spool rod 401 and has a larger diameter than the spool rod 401. Each of the first land portion 410 and the second land portion 420 is the same as the inner diameter of the valve body 210 that surrounds them, and thus the first and second land portions 410 and 420 are In a state in close contact with the inner surface, the spool 400 may slide in the longitudinal direction.

The third land portion 430 is formed between the first land portion 410 and the second land portion 420. When the spool 400 is inserted into the valve body 210, the first flow path 211 of the valve body 210 is located between the first land part 410 and the third land part 430 and the third land part The second flow path 212 of the valve body 210 is positioned between the 430 and the second land part 420.

In one embodiment, the third land portion 430 is a multi-diameter land portion. In the illustrated embodiment, the third land portion 430 includes a small diameter portion 431, an inclined portion 432, and a large diameter portion 433 sequentially formed from the first end side to the second end side. Since the configuration has the same or similar configuration to the third land portion 330 shown in FIG. 2, the third land portion 430 will be briefly described below.

The diameter of the small-diameter portion 431 (ie, the first diameter) is larger than the diameter of the spool rod 401, but is slightly smaller than the diameter of the inner surface of the valve body 210 surrounding the small-diameter portion 431. Accordingly, a predetermined gap is formed between the surface of the small diameter portion 431 and the inner surface of the valve body 210 surrounding the small diameter portion 431, and the gap may be, for example, between several to several hundreds of micrometers. In addition, the small diameter portion 431 may include one or more notches 435. The notch 435 may be formed at a corner of the small diameter portion 431 facing the first land portion 410.

An inclined portion 432 and a large-diameter portion 433 are sequentially formed from the small-diameter portion 431 toward the second end. The inclined portion 432 has an inclined surface whose diameter gradually increases from the small-diameter portion 431 to the large-diameter portion 433. The large-diameter portion 433 has a second diameter larger than the diameter of the first land portion 410, and in an embodiment, the large-diameter portion 433 and the second land portion 420 may have the same diameter.

A step portion is formed on the inner surface of the valve body 210 surrounding the inclined portion 432 of the third land portion 430, and the inclined portion 432 is moved to the step portion by sliding movement of the spool 400. The valve is opened or closed (on/off) by being in close contact or falling from the step. At this time, a minute gap of several to several hundred micrometers is formed between the small diameter portion 431 and the inner surface of the valve body 210 surrounding it, and at least one notch 435 is formed on the surface of the small diameter portion 431 , When the valve is turned on/off due to the movement of the spool 400, the flow rate between the two flow paths 211 and 212 may not increase or decrease rapidly, but may gradually increase and decrease, and the valve response and equipment operability may be improved compared to the prior art.

Meanwhile, in the illustrated embodiment, the spool rod 401 includes a first through passage 405 and a second through passage 406 therein. The first through passage 405 is a passage passing in the longitudinal direction from the first end of the spool rod 401 to the second end, and the second through passage 406 is a second land portion 420 of the spool rod 401 It is a flow path passing through in the radial direction of the spool rod 401 at a position between) and the second end. The first through passage 405 and the second through passage 406 are in communication with each other. Therefore, in the inner space of the valve body 210, the first and second land portions 410 and 420 of the spool rod 401 and the regions S2, S4 and S5 partitioned by the first and second ends are all in communication. do.

In addition, when the spool 400 moves left and right, one or more flow paths 215 are formed in the valve body 210 to discharge the fluid in the inner space of the valve body 210 to the outside or to inflow the external fluid into the inner space. In the illustrated embodiment, the flow path 215 is formed in the inner region S4 of the valve body 210 surrounding the second land portion 420 of the spool rod 401 and the second end side. That is, one end of the flow path 215 communicates with this region S4 and the other end is connected to a fluid tank storing, for example, a fluid. This region S4 also communicates with the first and second through passages 405 and 406 formed in the spool rod 401. Therefore, since the fluid in the divided regions S2, S4, S5 inside the valve body 210 can move freely, these regions S2, S4, and the valve body 210 when the spool 400 slides left and right. The spool 400 can move without obstruction of the fluid filled in S5).

The sliding block 220 will be described with reference to FIG. 4. 4(a) and 4(b) are perspective views of the sliding block 220 according to an exemplary embodiment viewed from different angles, respectively.

The sliding block 220 is slidably fitted into the through hole 213 of the valve body 210 and has the same cross-sectional shape as the cross-section of the through hole 213. For example, when the through hole 213 has a circular cross section, the sliding block 220 has a cylindrical shape with a circular cross section as shown in FIG. 4.

A side surface of the sliding block 220 may include one or more grooves 223 formed along the circumference of the side surface. Fluid may be filled in the groove 223 while the sliding block 220 is inserted into the through hole 213, and when the sliding block 220 moves within the through hole 213, the fluid filled in the groove 223 It can serve as a lubrication.

Both end surfaces of the sliding block 220 are formed with grooves having a predetermined shape, respectively. For example, as shown in Fig. 4(a), a straight groove 225 is formed on the end surface of the left end of the sliding block 220, and the end surface of the right end as shown in Fig. 4(b) In the cross-shaped recessed portion 227 is formed. The shape of the concave portions 225 and 227 may vary according to specific embodiments.

The left groove portion 225 of the sliding block 220 serves to alleviate impact and noise when in contact with the piston of the pilot portion (not shown). In other words, since the fluid is always filled in the area (S1) surrounding the left end of the sliding block 220, the groove portion 225 is also filled with fluid, and thus the piston of the pilot portion pushes the spool 400 to the right. When it hits the left side of 220, the impact or noise may be reduced when the piston and the sliding block 220 collide due to the fluid in the groove part 225.

The right concave portion 227 of the sliding block 220 allows the fluid in the region S2 surrounding the right end of the sliding block 220 to freely enter and exit the first through passage 405 of the spool rod 401. do. If there is no groove part 227, when the piston of the pilot part pushes the sliding block 220 to the right and the sliding block 220 pushes the first land part 410 of the spool to move the spool 400 to the right Since the fluid in this area S2 cannot escape to other places, the spool 400 does not move smoothly. Conversely, even when the spool 400 moves to the left by the spring 460, if there is no groove 227, the fluid filled in this region S2 cannot escape, so that the spool 400 cannot move. Therefore, if the groove portion 227 is formed on the right end surface of the sliding block 220, the fluid in this region (S2) can freely enter and exit other regions through the first through passage 405 of the spool rod 401. Smooth movement of the spool 400 can be ensured.

According to the configuration of the spool 400 of the second embodiment described above, since only two places of the first land portion 410 and the second land portion 420 of the spool 400 contact the inner surface of the valve body 210 Ease of processing the spool 400 is greatly improved.

In general, in order to manufacture by coaxially aligning the spool 400 and the inner space of the valve body 210, the spool 400 must be precisely processed while maintaining the straightness and parallelism, and the spool 400 is at least 2 to 3 Since it has four lands, it is not easy to process while continuously changing the diameter along the length direction. Since the processing between the land portion of the spool and the inner surface of the valve body 210 must be processed within an error of several micrometers or less so that the fluid does not leak, the processing is more difficult as the number of places where the spool and the inner surface of the valve body contact each other. Conventionally, there were at least three or four or more areas where the spool and the inner surface of the valve body contact each other. For example, in the case of the conventional valve of FIG. 1, three spools 30 are in contact with the inner surface of the valve body at the left end region of the spool rod 31 and the first and second lands 32 and 33.

However, according to the second embodiment of the present invention, the left end side of the spool rod 401 is removed and separated into a separate sliding block 220, and the inclined portion 432 of the third land portion 430 and the valve body are Depending on whether the inner stepped portion is in close contact, the flow path is opened/closed, and the small diameter portion 431 and the large diameter portion 433 of the third land portion 430 do not come into contact with the inner surface of the valve body 210. Only the 410 and the second land portion 420 are configured to contact the inner surface of the valve body 210, and by this configuration, the ease of processing when manufacturing the valve body 210 and the spool 400 can be greatly improved. . Furthermore, due to the improved ease of processing, the need to use a sleeve (eg, 20 in FIG. 1) between the valve body 210 and the spool 400 is reduced, thereby reducing the overall valve volume and reducing manufacturing cost.

Now, a coupling structure of the spool rod 401 and the spring 460 according to an embodiment will be described with reference to FIGS. 5 and 6. 6 is an exploded perspective view of a right portion of the spool 400 according to an embodiment, and FIG. 7 is a side view.

Referring to the drawings, a spring 460 in which the spool 400 is fitted to the spool rod 401, ring members 440 and 450 disposed at both end sides of the spring 460, and a spool rod 401 It may include a spring support 470 coupled to the second end side of the.

The spring 460 is disposed by being fitted in the spool rod 401 between the second land portion 420 and the second end of the spool rod 401. The first ring member 440 is interposed between the second land portion 420 and the spring 460 and is fitted into the spool rod 401. Since the spring 460 may be supported by direct contact with the second land part 420, the first ring member 440 may be omitted in an alternative embodiment. The second ring member 450 is fitted in the spool rod 401 at a position between the spring 460 and the spring support 470 and is configured to be slidable along the spool rod 401.

The spring support 470 is coupled to the second end side of the spool rod 401 to support the spring 460. The diameter of the spring support 470 is larger than the diameter of the spool rod 401, and a step portion is formed between the spool rod 401 and the spring support 470. Accordingly, the movement of the second ring member 450 in the right direction may be limited by this step. As described with reference to Fig. 3, the spring support 470 includes a through passage 471 penetrating therein in the longitudinal direction. The through passage 471 is configured to be aligned coaxially with the first through passage 405 of the spool rod 401 to communicate with the first through passage 405.

Meanwhile, as shown in FIG. 3, a cover member 240 for sealing the inner space of the valve body 210 is attached to the right end of the valve body 210. In the illustrated embodiment, the cover member 240 may be coupled to the valve body 210 by screwing, or may be coupled to the valve body 210 by another coupling method in an alternative embodiment.

At this time, the second end-side diameter of the valve body 210 is larger than the inner diameter of the cover member 240, and thus a step portion is formed between the valve body 210 and the cover member 240. In addition, the diameter of the spring support 470 is the same as or less than the inner diameter of the inner surface of the cover member 240 is configured to be larger than the inner diameter of the second ring member 450 is the inner diameter of the cover member 240. According to this configuration, when the spool 400 is pushed in the direction toward the second end side (that is, to the right in Fig. 3) by, for example, a piston of the pilot part (not shown) to open the valve, the second ring member 450 ) Is supported by the stepped portion between the valve body 210 and the cover member 240 so that it can no longer move to the right, so as the spool 400 moves to the right, the spring 460 is formed on both ring members (440,450). ) Will contract. Thereafter, when the piston of the pilot part retreats to the left to close the valve, the spool 400 may move to the left again by the elastic force of the spring 460 and return to the original position.

7 shows the advantages of coupling the spring 460 to the spool 400 as described above.

In the conventional valve as shown in Fig. 1, the sleeve 20 is attached to the valve housing 10, the spool 30 is inserted into the inner space of the sleeve 20, and the spring 17 is attached to the spool rod 31 of the spool 30. The valve is manufactured by screwing the cover member 50 while being inserted into the valve.

However, when the cover member 50 is fastened to the valve body 10, the spring 17 is pressed and contracted to a certain extent so that the spring 17 elastically supports the spool 30. During fastening, the spring 17 may be bent or may not be accurately aligned with the spool rod 31, but the operator cannot see the state of the spring 17 with his own eyes, so he cannot check.

Ideally, the spring should have the same force-displacement characteristics when contracting and returning by applying force to the spring and returning. That is, as shown in Fig. 7(a), the spring must exhibit the same length displacement during the contraction process and the return process for the same force. However, in the case of manufacturing in the conventional method as above, since the spring is manufactured without knowing the degree of contraction or bending of the spring, the spring is manufactured in an incorrect state and has a different path when contracting and returning, for example, as shown in Fig. 7(b). There are many, and there is a problem that the force-displacement characteristics are different for each valve.

However, according to the present invention, the spring 460 is configured to manufacture the spool 400 in an integral type, so that when the spring 460 is inserted into the spool rod 401 and fastened with the cover member 470, the operator Since it can be manufactured by directly checking the contraction state of 460), the above conventional problems can be solved, and all spools can have the same force-displacement characteristics.

As described above, those of ordinary skill in the field to which the present invention belongs can understand that various modifications and variations are possible from the description of this specification. For example, in the above-described embodiment, it is shown that the spring-spool coupling structure of Figs. 5 and 6 is applied to the spool 400 of the second embodiment, but this spring-spool coupling structure is the spool 300 of the first embodiment. Of course, it can also be applied. Therefore, the scope of the present invention is limited to the described embodiments and should not be defined, and should be defined by the claims and equivalents to the claims to be described later.

100, 210: valve body
220: sliding block
300, 400: spool
301.401: spool rod
310, 320, 330, 410, 420, 430: land part
331, 431: small diameter part
332, 432: slope
333, 433: large diameter part
335, 435: notch

Claims (14)

A valve body having a cylindrical internal space and having a first flow path 111 and a second flow path 112 formed on the side of the internal space, and a spool arranged to slide in the longitudinal direction of the cylindrical shape within the valve body As a flow control valve having 300, the spool 300,
A spool rod 301 in the shape of a cylinder and having a first end and a second end;
A first land portion 310 having a larger diameter than the spool rod and formed close to the first end portion;
A second land portion 320 having a larger diameter than the first land portion and spaced apart from the second end portion; And
Including; a multi-diameter third land portion 330 formed between the first land portion and the second land portion,
The third land portion 330 includes a small diameter portion 331, an inclined portion 332, and a large diameter portion 333 sequentially formed from the first end side to the second end side,
The small-diameter portion 331 has a first diameter smaller than the first land portion, the large-diameter portion 333 has a second diameter larger than the first land portion but equal to or smaller than the second land portion, and the inclination The portion 332 is interposed between the small-diameter portion and the large-diameter portion and is configured to gradually increase in diameter from the first diameter to the second diameter. The method of claim 1, wherein the spool,
A spring (460) fitted into the spool rod between the second land portion and the second end portion;
A spring support 470 coupled to the second end of the spool rod; And
Including; a first ring member 450 of a ring shape that is fitted to the spool rod at a position between the spring 460 and the spring support portion 470 and is slidable,
When the spool moves in the direction toward the second end, the first ring member (450) is supported by a step portion of the inner space of the valve body so that the spring contracts. The method of claim 2,
The flow control valve further comprising a ring-shaped second ring (440) fitted to the spool rod at a position between the second land portion and the spring (460). As a spool for flow control valve,
A spool rod 401 in the shape of a cylinder and having a first end and a second end;
A first land portion 410 having a larger diameter than the spool rod and formed at the first end portion;
A second land portion 420 having a larger diameter than the first land portion and spaced apart from the second end portion; And
Including; a multi-diameter third land portion 430 formed between the first land portion and the second land portion,
The third land portion 430 includes a small diameter portion 431, an inclined portion 432, and a large diameter portion 433 sequentially formed from the first end side to the second end side,
The small diameter portion 431 has a first diameter smaller than the first land portion, and the large diameter portion 433 has a second diameter larger than the first land portion but equal to or smaller than the second land portion, and the inclination The portion 432 is interposed between the small-diameter portion and the large-diameter portion, and a spool for a flow control valve, characterized in that the diameter gradually increases from the first diameter to the second diameter. The method of claim 4,
When the spool is disposed in the inner space of the flow control valve, the inclined portion 432 of the third land portion is a first space between the first land portion 410 and the third land portion 430 of the inner space And a spool for a flow control valve configured to open and close a second space between the second land part 420 and the third land part 430 of the inner space. The method of claim 4, wherein the spool,
A first through passage 405 penetrating in the longitudinal direction from the first end of the spool rod 401 to the second end; And
A second through passage 406 that penetrates the spool rod in a radial direction at a position between the second land portion and the second end portion of the spool rod 401 and communicates with the first through passage 405; Flow control valve spool, characterized in that. The method of claim 4, wherein the spool,
A spring (460) fitted into the spool rod between the second land portion and the second end portion;
A spring support 470 coupled to the second end of the spool rod; And
Including; a first ring member 450 of a ring shape that is fitted to the spool rod at a position between the spring 460 and the spring support portion 470 and is slidable,
When the spool is disposed in the inner space of the flow control valve and the spool moves toward the second end, the first ring member 450 is supported by a step in the inner space of the flow control valve, so that the spring is Spool for flow control valve, characterized in that configured to retract. The method of claim 7,
A spool for a flow control valve, further comprising a ring-shaped second ring member (440) fitted to the spool rod at a position between the second land portion and the spring. The method of claim 7,
A first through passage 405 which passes through the spool from a first end to a second end of the spool rod 401 in a longitudinal direction; And a second through passage 406 that penetrates the spool rod in a radial direction at a position between the second land portion and the second end of the spool rod 401 and communicates with the first through passage 405. Including,
The spring support 470 passes through the spring support in a longitudinal direction and includes a third through passage 471 communicating with the first through passage 405. The method of claim 4,
A spool for a flow control valve, characterized in that at least one notch 435 is formed at a corner of the small diameter portion 431 facing the first end side. As a flow control valve,
The flow control valve spool according to any one of claims 4 to 10;
It has a cylindrical inner space for accommodating the spool, and includes a first flow path 211 and a second flow path 212 formed on the side of the internal space, and a through hole 213 formed in the direction toward the first end. Valve body 210; And
A flow control valve comprising: a sliding block 220 disposed to be slidably fitted in the through hole 213. The method of claim 11,
A pilot portion attached to the outside of the through hole 213 of the valve body 210;
The piston or hydraulic pressure of the pilot part pushes the sliding block 220, and the sliding block 220 pushes the first land part 410 of the spool, so that the spool slides in the direction toward the second end. Flow control valve. The method of claim 11,
A flow control valve, characterized in that at least one concave portion (227) is formed on an end surface of the first end of the sliding block (220) in contact with the first land portion (410) of the spool. The method of claim 13,
A flow control valve, characterized in that at least one concave portion (225) is formed on an end surface of the second end opposite to the first end of the sliding block (220).

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