KR20200065664A - Spool with improved workability and precise controllability and a flow control valve using the spool - Google Patents

Abstract

An embodiment of the present invention relates to a flow control valve which comprises: a valve main body having a cylindrical inner space and provided with a first flow path (111) and a second flow path (112) formed on a side surface of the inner space; and a spool (300) which is arranged to be slidable in a longitudinal direction of the cylindrical shape in the valve main body. Here, the spool (300) comprises: a spool rod (301) of a cylindrical shape, having a first end unit and a second end unit; a first land unit (310) which has a diameter greater than that of the spool rod and is formed to be close to the first end unit; a second land unit (320) which has a diameter greater than that of the first land unit and is formed after being spaced apart towards the second end unit; and a third land unit (330) of multiple diameters, which is formed between the first land unit and the second land unit. Here, the third land unit (330) is characterized by comprising a small diameter unit (331), an inclination unit (332) and a large diameter unit (333) which are sequentially formed from the first end unit towards the second end unit. Therefore, valve responsiveness can be increased.

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 provided with the spool, and more particularly, to a spool having improved processability and control precision and a flow control valve having the same.

In general, industrial equipment such as excavators, cranes, and forklifts have hydraulic actuators such as cylinders for driving equipment, and these hydraulic actuators include a plurality of flow control valves for controlling the 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 into 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.

In the case of opening the valve, when the spool 30 slides to the right by, for example, a piston (not shown) of the pilot portion, the first flow path 11 and the second flow path 12 are opened and 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 portion 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 only slightly open, a large amount of fluid flows through the gap between the second land part 33 and the sleeve 20. There is a problem that the valve control is not easy.

In addition, the more the area where the spool 30 and the inner space of the valve contact each other when manufacturing the valve, the more difficult it is to manufacture the spool. Since the spool 30 and the inner space of the valve contact at least 3 or 4 locations, such as 3 or 4 locations, precision processing within a few micrometer error is required to process the spool while maintaining straightness and parallelism. Processing cost increased.

Moreover, since it is very difficult to directly process the valve body with this precision, a separate sleeve 20 was conventionally processed. That is, the valve was manufactured by processing the sleeve 20 which is relatively easy to process compared to the valve housing 10, fastening the valve housing 10, and inserting the spool 30 into the inner space of the sleeve 20. This adds parts, which increases the valve volume and cost.

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

The present invention is to solve the above problems, and provides a spool for preventing shock from being applied to the equipment due to a sudden amount of fluid change when the valve is turned on/off, and improving valve responsiveness and equipment operability, and a flow control valve having the same do.

According to an embodiment of the present invention, it is possible to reduce the volume of the valve and reduce the manufacturing cost by improving the ease of processing the valve body and the spool by minimizing the number of areas where the inner surface of the spool and the valve body abut, and eliminating the need for a sleeve. An spool and a flow control valve having the same are provided.

In addition, according to an embodiment of the present invention, by constructing a spool-spring integral spool with a spring attached to the spool, a spool capable of preventing the spring from being incorrectly fastened during valve manufacturing and allowing all spools to have the same force-displacement characteristics It provides a flow control valve equipped with this.

According to an embodiment of the present invention, a valve body having a cylindrical inner space and a first flow path 111 and a second flow path 112 formed on a side surface of the inner space and the length of the cylindrical shape in the valve body A flow control valve having a spool (300) arranged to be slidable in a direction, wherein the spool (300) comprises 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; A second land part 320 having a larger diameter than the first land part and spaced apart in the second end side direction; And a multi-diameter third land part 330 formed between the first land part and the second land part, wherein the third land part 330 is in the direction from the first end side to the second end side. It is provided with a small diameter portion 331, a slope portion 332, and a large diameter portion 333 sequentially formed, the small diameter portion 331 has a first diameter smaller than the first land portion, the large diameter portion 333 ) Has a second diameter that is larger than or equal to the second land portion but smaller than or equal to the second land portion, and the inclined portion 332 is interposed between the small diameter portion and the large diameter portion to be the diameter from the first diameter to the second diameter. It is configured to gradually increase, and when the spool moves in the direction of the first end, the inclined side surface of the inclined portion 332 of the third land portion contacts the first step portion of the interior space of the valve body while the first space Disclosed is a flow control valve, which is configured to close between the second space and the first space and the second space to communicate when the spool moves toward the second end.

According to an embodiment of the present invention, as a spool for a flow control valve, the cylinder-shaped spool rod 401 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; A second land portion 420 having a larger diameter than the first land portion and being spaced apart in the second end side direction; And a multi-diameter third land part 430 formed between the first land part and the second land part, wherein the third land part 430 is in the direction from the first end side to the second end side. It is provided with a small diameter portion 431, a slope portion 432, and a large diameter portion 433 formed sequentially, the small diameter portion 431 has a first diameter smaller than the first land portion, the large diameter portion 433 ) Has a second diameter that is larger than or equal to the second land portion but smaller than or equal to 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 gradually increase.

According to an embodiment of the present invention, as a flow control valve, the spool for the flow control valve described above; It has a cylindrical inner space for accommodating the spool, and is provided with a first flow path 211 and a second flow path 212 formed on a side surface of the inner space and a through hole 213 formed in the first end side direction. Valve body 210; And a sliding block (220) slidably inserted into the through hole (213).

According to an embodiment of the present invention, when the valve is opened by forming a land portion of the spool as a cylindrical portion having a diameter smaller than the inner diameter of the valve body and a diameter-increasing diameter increasing portion and forming at least one notch portion in the cylindrical portion It can have an effect of preventing shock from being applied to the equipment due to the rapid flow of fluid and improving valve responsiveness and equipment operability.

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

According to one embodiment of the present invention, by attaching the spring to the spool and configured to manufacture the spool integrally, when the spring is fastened, the operator can check and produce the spring's contraction degree or state, so that all spools have the same force-displacement of the spring. It can have characteristics.

1 is a view for explaining a conventional valve structure,
Figure 2 is a view for explaining a spool and a flow control valve having the same according to the first embodiment of the present invention,
3 is a view for explaining a spool according to a second embodiment of the present invention and a flow control valve having the same,
4 is a view for explaining a sliding block according to an embodiment,
5 and 6 are views for explaining the coupling structure between the spool and the spring according to one embodiment,
7 is a view for explaining the effect of the coupling structure between the spool and the spring according to one 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 to ensure that the disclosed contents are thorough and complete and that the spirit of the present invention is 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 the present specification, the singular form also includes the plural form unless otherwise specified in the phrase. As used herein,'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 and understand the invention. However, a reader who has knowledge in this field to understand the present invention can recognize that it can be used without a variety of specific content. It should be noted that, in some cases, parts that are commonly known in describing the invention and that are not significantly related to the invention are not described in order to avoid confusion in describing the invention.

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

Referring to the drawings, the 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 the inner surface of the housing 110, and slides while the spool 300 is in contact with the inner surface of the sleeve 120. Can be. However, in an alternative embodiment, the sleeve 120 may be omitted, in which case the spool 300 is configured to slide while directly contacting the inner surface of the housing 110.

The valve body 100 has an approximately cylindrical inner space, and the first flow path 111 and the second flow path 112 are formed on the side surface of the interior space. In the illustrated embodiment, the first flow path 111 may be connected to a 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 be able to slide and reciprocate a predetermined distance in the longitudinal direction of the cylindrical interior 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 drawings, a pilot portion may be installed at the left end of the spool 300. have. The pilot portion has a piston (not shown) moving left and right (on the drawing) by a solenoid coil or fluid, and this piston can slide the spool 300 to the right by pushing the left end side of the spool 300. 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 slides to the right. The control of the operation of the spool 300 by the pilot portion and the spring 117 is a known technique, so 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 interior space of the valve body 100 does not interfere with the sliding movement of the spool 300 from side to side. For example, in the illustrated embodiment, the fluid in the region S2 between the first end side of the spool rod 301 and the first land portion 310 and the region S4 between the second end side and the second land portion 320. ) To allow the fluid filled in to move freely, the inner passage 115 is formed in the valve housing 110 and the through holes 121 and 122 communicating with the inner passage 115 are also formed in the sleeve 120.

In the illustrated embodiment, the spool 300 is provided with first to third land portions 310, 320, and 330 having a diameter greater than that of the cylinder-shaped spool rod 301 and a spool rod 301 having a predetermined diameter. can do. The spool rod 301 and the first to third land portions 310, 320, 330 may be integrally manufactured, and in alternative embodiments, the spool rod 301 and the land portions 310, 320, 330 may be separately manufactured and then combined. .

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

In one embodiment, the first land part 310 and the second land part 320 are formed on the left and right sides, respectively, at the center of the spool rod 301. 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 are of the valve body 100. The spool 300 can slide in the longitudinal direction in close contact with the inner surface.

The third land part 330 is formed between the first land part 310 and the second land part 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 portion 310 and the third land portion 330, and the second flow path 112 has the second land portion 320 and the third land. It communicates with the space between the parts 330.

In one embodiment, the third land part 330 is a multi-diameter land part. In the illustrated embodiment, the third land portion 330 is formed from the first end side to the second end side direction (ie, from left to right in the drawing), the small-diameter portion 331, the inclined portion 332, 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 is 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 and is configured to gradually increase in diameter 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 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 there is a predetermined gap between the small-diameter portion 331 and the inner surface of the sleeve 120 surrounding it. This gap serves to prevent a rapid increase in the flow rate between the two flow paths when the two flow paths 111 and 112 are communicated 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 several hundred 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 is formed on the surface of the small-diameter portion 331 but may be formed at the corner of the small-diameter portion 331 facing the first land portion 310 side. By the notch 335, it is possible to further prevent the rapid increase in the flow rate between the two flow paths 111 and 112.

The inclined portion 332 is integrally formed in the direction of the second end side 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 side. In the direction of the second end side of the inclined portion 332, the large diameter portion 333 is integrally formed. The large diameter portion 333 has a second diameter that is 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 A step portion is also formed in the sleeve 120.

By this configuration, the valve opening and closing operation is performed by sliding the spool 300 so that the inclined portion 332 is in close contact with the step portion of the sleeve 120 or falls from the step portion. That is, when the spool 300 moves to the left, the inclined surface of the inclined portion 332 comes into contact with the stepped portion of the sleeve 120 and is closed between the first flow path 111 and the second flow path 112 and the spool 300 is opened. When moving to the right, the inclined surface of the inclined portion 332 falls 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, when the opening/closing switching of the first flow path 111 and the second flow path 112 is possible, it is possible to prevent a rapid fluctuation of the flow rate. That is, the distance between the small diameter portion 331 of the third land portion 330 and the inner diameter of the sleeve 120 surrounding it is very finely designed in a few to hundreds of micrometers, and the notch 335 is provided in the small diameter portion 331. By forming, the flow rate passing through the two flow paths 111 and 112 while moving in the right direction of the spool 300 does not increase rapidly but gradually increases gradually. Therefore, there is an advantage of improving the valve responsiveness and equipment operability, and reducing the impact applied to the cylinder 70 when the valve is switched on/off as compared to the prior art.

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 second embodiment shown, a separate sleeve (eg, 120 of FIG. 2) is not required in the valve body 210 and the spool 400 can be disposed in direct contact with the valve body 210. However, in alternative embodiments, a sleeve may be coupled within the valve body 210.

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

A through hole 213 communicating with the outside is formed at a first end (left end in the drawing) side of the valve body 210, and a sliding block 220 is fitted in the slidable state in the through hole 213 have. A cover member 230 that surrounds the through-hole 213 and seals from the outside is coupled to the left side of the through-hole 213. 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 portion 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. You can slide.

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 surrounding them, so that the first and second land portions 410 and 420 of the valve body 210 The spool 400 can slide in the longitudinal direction in close contact with the inner surface.

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

In one embodiment, the third land part 430 is a multi-diameter land part. 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 in a direction from a first end side to a second end side. Since the configuration has the same or similar configuration to the third land portion 330 illustrated in FIG. 2, the third land portion 430 will be briefly described below.

The diameter of the small diameter portion 431 (that is, the first diameter) is larger than the diameter of the spool rod 401, but is 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 it, and this gap may be, for example, between several hundreds to hundreds of micrometers. Also, the small-diameter portion 431 may include one or more notches 435. The notch 435 may be formed at an edge of the small-diameter portion 431 facing the first land portion 410 side.

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

A stepped 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 stepped portion by sliding movement of the spool 400. The valve is opened/closed (on/off) by close contact or dropping from the stepped portion. At this time, a small gap of several to several hundreds of micrometers is formed between the small diameter portion 431 and the inner surface of the valve body 210 surrounding it, and one or more notches 435 are formed on the surface of the small diameter portion 431. , When the valve is turned on/off by the movement of the spool 400, the flow rate between the two flow paths 211 and 212 can be gradually increased and decreased gradually without increasing or decreasing rapidly, and may have improved valve responsiveness and equipment operability 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 flow passage penetrating longitudinally from the first end to the second end of the spool rod 401, and the second through passage 406 is the second land portion 420 of the spool rod 401. ) And the second end is a flow path penetrating in the radial direction of the spool rod 401. The first through passage 405 and the second through passage 406 communicate 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, one or more flow paths 215 are formed in the valve body 210 in order to discharge fluid in the interior space of the valve body 210 to the outside or to flow external fluid into the interior space when the spool 400 moves left and right. In the illustrated embodiment, the flow path 215 is formed in the inner region S4 of the valve body 210 surrounding between the second land portion 420 and the second end side of the spool rod 401. That is, one end of the flow path 215 communicates with this region S4 and the other end is connected to, for example, a fluid tank for storing 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 partitioned regions S2, S4, and S5 inside the valve body 210 can freely move, these regions S2, S4 of the valve body 210 when the left and right sliding movements of the spool 400 move. S5), the spool 400 can move without disturbing the fluid.

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 one embodiment, as viewed from different angles, respectively.

The sliding block 220 is slidably inserted 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 cross section of the through hole 213 is circular, as shown in FIG. 4, the sliding block 220 has a cylindrical shape with a circular cross section.

The side of the sliding block 220 may include one or more grooves 223 formed along the circumference of the side. When the sliding block 220 is fitted in the through hole 213, the groove 223 may be filled with fluid, and when the sliding block 220 moves within the through hole 213, the fluid filled in the groove 223 is filled. It can serve as a lubrication.

On the both end surfaces of the sliding block 220, recesses of a predetermined shape are respectively formed. For example, as shown in Fig. 4 (a), the end face of the left end of the sliding block 220 is formed with a slotted groove 225 in a straight shape, and the end face of the right end as shown in Fig. 4 (b). In the cross-shaped recess 227 is formed. The shape of the recesses 225 and 227 may vary depending on the specific embodiment.

The left recess 225 of the sliding block 220 serves to relieve shock and noise when in contact with the piston of the pilot portion (not shown). That is, since the fluid is always filled in the region S1 surrounding the left end of the sliding block 220, the groove portion 225 is also filled with fluid, so that the piston of the pilot portion slides the block to push the spool 400 to the right. When colliding with the left side of the 220, due to the fluid in the recess 225, impact or noise may be reduced when the piston and the sliding block 220 collide.

The right recess 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 227, when the piston of the pilot pushes the sliding block 220 to the right and the sliding block 220 pushes the first land portion 410 of the spool to move the spool 400 to the right. The spool 400 cannot move smoothly because the fluid in this area S2 cannot escape to another place. Conversely, even if the spool 400 moves to the left by the spring 460, the fluid filled in this area S2 cannot escape without the recess 227, so the spool 400 cannot move. Therefore, when the groove 227 is formed on the right end surface of the sliding block 220, the fluid in this area S2 can freely enter and exit the other area 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, 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. The ease of processing of the spool 400 is greatly improved.

In general, in order to manufacture the spool 400 and the valve body 210 by coaxially aligning the inner space, the spool 400 must be precisely processed while maintaining straightness and parallelism, and the spool 400 is at least two to three. Since it has a dog's land, it is not easy to process while continuously changing the diameter along the length direction. Since the land between the spool and the inner surface of the valve body 210 must be processed within an error of a few micrometers or less to prevent fluid from leaking, the more places the spool and the inner surface of the valve body contact, the more difficult the machining. Conventionally, there have been at least three or four areas where the spool and the inner side of the valve body contact. For example, in the case of the conventional valve of FIG. 1, there are three spools 30, that is, the left end region of the spool rod 31 and the first and second land portions 32 and 33 contact the inner surface of the valve body.

However, according to the second embodiment of the present invention, the left end side of the spool rod 401 is removed to separate it into a separate sliding block 220, and the inclined portion 432 of the third land portion 430 and the valve body The flow path is opened/closed depending on whether or not the inner stepped portion adheres, and the small land portion 431 and the large diameter portion 433 of the third land portion 430 do not contact the inner surface of the valve body 210, so that the first land portion Only the 410 and the second land part 420 are configured to contact the inner surface of the valve body 210, and the ease of processing can be greatly improved when the valve body 210 and the spool 400 are manufactured by such a configuration. . Moreover, the need to use a sleeve (for example, 20 in FIG. 1) between the valve body 210 and the spool 400 is reduced due to the improvement in the ease of processing, 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 portion of the right side 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 of the.

The spring 460 is interposed between the second land portion 420 and the second end of the spool rod 401 to be fitted to the spool rod 401. The first ring member 440 is interposed between the second land portion 420 and the spring 460 to fit the spool rod 401. Since the spring 460 may be directly supported by the second land portion 420, the first ring member 440 may be omitted in an alternative embodiment. The second ring member 450 is fitted to 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 is formed between the spool rod 401 and the spring support 470. Therefore, the movement in the right direction of the second ring member 450 may be limited by this step. As described with reference to Figure 3, the spring support 470 includes a through passage 471 penetrating therein in the longitudinal direction. The through passage 471 is arranged to be coaxially aligned with the first through passage 405 of the spool rod 401 and configured to communicate with the first through passage 405.

Meanwhile, as illustrated 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 other coupling methods in alternative embodiments.

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

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

In the conventional valve as shown in Figure 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 the spool rod 31 of the spool 30. The cover member 50 is fastened by screwing while being fitted into the valve.

However, when the cover member 50 is fastened to the valve body 10, the spring 17 is compressed to a certain extent by pressing the spring 17 so as to elastically support the spool 30. When tightening, the spring 17 may bend or may not be exactly aligned with the spool rod 31, but the operator cannot check the state of the spring 17 because it cannot be seen with the eye.

Ideally, the spring should have the same force-displacement characteristics upon contraction and return when it is contracted by force and then returned. That is, as shown in Fig. 7(a), the spring should exhibit the same length displacement in the contraction and return process of the spring for the same force. However, in the case of manufacturing in the conventional manner as described above, since the spring is manufactured in a wrong state because it is manufactured without knowing the degree of contraction or bending of the spring, for example, as shown in FIG. There are many problems with force-displacement characteristics for each valve.

However, according to the present invention, the spring 460 is configured to manufacture the spool 400 as an integral type, and when the spring 460 is inserted into the spool rod 401 and fastened with the cover member 470, the worker can use the spring ( Since the contraction state of 460) can be directly checked and manufactured, the conventional problems as described above can be solved, and all spools can have the same force-displacement characteristics.

As described above, those skilled in the art to which the present invention pertains can understand that various modifications and variations are possible from the description of this specification. For example, in the above-described embodiment, although the spring-spool coupling structure of FIGS. 5 and 6 is illustrated as being applied to the spool 400 of the second embodiment, such a spring-spool coupling structure is shown as the spool 300 of the first embodiment. Of course, it can be applied to. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the following claims, but also by the claims and equivalents.

100, 210: valve body
220: sliding block
300, 400: spool
301.401: Spool Road
310, 320, 330, 410, 420, 430: Land section
331, 431: Small diameter neck
332, 432: slope
333, 433: large diameter
335, 435: Notch

Claims (14)

A spool having a cylindrical interior space and having a first flow path 111 and a second flow path 112 slidable in a valve body formed on a side surface of the interior space and in the valve body in the longitudinal direction of the cylindrical shape As a flow control valve having a (300), the spool (300),
A spool rod 301 having a cylindrical shape 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;
A second land part 320 having a larger diameter than the first land part and spaced apart in the second end side direction; And
It includes; 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, a slope portion 332, and a large diameter portion 333 sequentially formed from the first end side to the second end side direction,
The small diameter portion 331 has a first diameter smaller than the first land portion, and the large diameter portion 333 has a second diameter larger than or equal to the second land portion but smaller than the first land portion, and the inclination Part 332 is interposed between the small-diameter portion and the large-diameter portion flow control valve, characterized in that 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 to the spool rod between the second land portion and the second end;
A spring support 470 coupled to the second end of the spool rod; And
It includes; a first ring 450 of a ring shape that is fitted to the spool rod at a position between the spring 460 and the spring support 470;
When the spool moves in the direction of the second end, the sliding ring 450 is supported by the second step portion of the space inside the valve body, so that the spring is configured to contract the flow control valve. According to claim 2,
And a second ring 440 having a ring shape 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 that is cylindrical and has 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;
A second land portion 420 having a larger diameter than the first land portion and being spaced apart in the second end side direction; And
It includes; 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, a slope portion 432, and a large diameter portion 433 sequentially formed in the direction 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 or equal to the second land portion but smaller than the first land portion, and the inclination The portion 432 is interposed between the small diameter portion and the large diameter portion spool for a flow control valve, characterized in that configured to gradually increase in diameter 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 the first space between the first land portion 410 and the third land portion 430 of the inner space. And a second space between the second land part 420 and the third land part 430 of the inner space. The method according to claim 4, wherein the spool,
A first through passage 405 penetrating longitudinally from the first end to the second end of the spool rod 401; And
And a second through passage 406 passing through the spool rod in the radial direction at a position between the second land portion and the second end of the spool rod 401 and communicating with the first through passage 405. Spool for a flow control valve, characterized in that. The method according to claim 4, wherein the spool,
A spring 460 fitted to the spool rod between the second land portion and the second end;
A spring support 470 coupled to the second end of the spool rod; And
It includes; 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 470;
When the spool moves in the direction of the second end, the first ring member 450 is supported by the second step portion of the space inside the valve body, so that the spring is configured to contract, so that the spool for the flow control valve. 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 through which the spool penetrates longitudinally from a first end to a second end of the spool rod 401; And a second through passage 406 penetrating 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 communicating with the first through passage 405. Including,
The spring support 470 is a spool for a flow control valve, characterized in that it comprises a third through flow passage (471) passing through the spring support in the longitudinal direction and communicating with the first through flow passage (405). The method of claim 4,
Spool for a flow control valve, characterized in that at least one notch (435) is formed at the edge of the small-diameter portion 431 toward the first end side. As a flow control valve,
The spool for the flow control valve according to any one of claims 4 to 10;
It has a cylindrical inner space for accommodating the spool, and is provided with a first flow path 211 and a second flow path 212 formed on a side surface of the inner space and a through hole 213 formed in the first end side direction. Valve body 210; And
And a sliding block (220) slidably inserted into 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;
It is characterized in that the piston or hydraulic pressure of the pilot portion pushes the sliding block 220 and the sliding block 220 pushes the first land portion 410 of the spool so that the spool slides toward the second end side. Flow control valve. The method of claim 11,
Flow control valve, characterized in that at least one groove portion 227 is formed on the 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,
Flow control valve, characterized in that at least one groove 225 is formed on the end surface of the second end opposite to the first end of the sliding block (220).

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