JP2020085088A - Solenoid valve, direction switching valve and construction machine - Google Patents

Abstract

To provide a solenoid valve capable of making a sleeve have a plurality of housing spaces with different diameters simply and highly accurately, and a direction switching valve and a construction machine comprising such a solenoid valve.SOLUTION: A solenoid valve 10 comprises a valve body part 11, a drive part 12, a spool 13, a sleeve body part 15, and a sleeve dividing part 16. The spool 13 has a large diameter part 23 and a small diameter part 24. The drive part 12 drives the spool 13. The sleeve body part 15 has a body housing space 25 in which a part of the spool 13 is located, and slidably supports the spool 13. The sleeve dividing part 16 is fixed between the valve body part 11 and the sleeve body part 15, has a dividing and housing space 26 in which the large diameter part 23 or the small diameter part 24 of the spool 13 is located, and slidably supports the spool 13.SELECTED DRAWING: Figure 1

Description

The present invention relates to a solenoid valve, a directional control valve and a construction machine.

2. Description of the Related Art In a hydraulic system, a solenoid valve having an excellent response speed is widely used as a valve body that controls the flow of pressure oil. In particular, in recent years, there has been an increasing demand for electrically driving hydraulic devices, and it is expected that the use of solenoid valves will continue to expand.

Patent Document 1 discloses an electromagnetic proportional valve, which is a type of electromagnetic valve. In this solenoid proportional valve, the spool is driven by the drive rod, the flow path configuration of the solenoid proportional valve is determined according to the position of the spool in the spool housing hole, and the flow of oil (pressure oil) in the solenoid proportional valve can be adjusted. it can.

JP, 2017-20541, A JP-A-08-170353

The spool of the solenoid valve has a large-diameter portion and a small-diameter portion having different outer diameters, and the area spreading in the radial direction perpendicular to the moving direction (that is, the axial direction) of the spool is different between the large-diameter portion and the small-diameter portion. .. Due to this area difference between the large diameter portion and the small diameter portion, the force that the spool receives from the pressure oil from one axial direction to the other and the force that the spool receives from the pressure oil from the other axial direction are Not the same. The force from such pressure oil that the spool receives, the force from the drive rod that the spool receives from one axial direction toward the other, and the force from the spring that the spool receives from the other axial direction toward the one side. The spools are arranged in a balanced position, and the flow path configuration of the solenoid valve is determined.

A sleeve that movably supports such a spool has a plurality of inner diameters corresponding to the large diameter portion and the small diameter portion of the spool. In the range in which the large diameter portion of the spool moves in the sleeve, there is a storage space having a relatively large diameter corresponding to the large diameter portion. Further, in the range in which only the small diameter portion of the spool moves in the sleeve, there is a storage space having a relatively small diameter corresponding to the small diameter portion. As described above, the sleeve has a plurality of accommodation spaces having different diameters corresponding to the large diameter portion and the small diameter portion of the spool.

Processing for forming a housing space having different diameters corresponding to the large diameter portion and the small diameter portion of the spool in a single sleeve requires high accuracy and is not easy. The difference between the outer diameter of the large diameter portion and the outer diameter of the small diameter portion of the actual spool is often about several millimeters (mm) to 0.1 millimeter. Therefore, when forming the accommodation spaces having different diameters in the sleeve, processing accuracy of about several millimeters to 0.1 millimeters is required. Further, in order to form a plurality of accommodating spaces having different diameters into a single sleeve while adjusting the relative positions thereof to a desired position, a very high processing accuracy is required. For example, a plurality of accommodation spaces having different diameters provided in the sleeve are required to be arranged so that their centers extending in the axial direction coincide with each other. Processing control is required.

The diameter of the accommodation space in the sleeve and the relative position between the accommodation spaces are factors that influence the characteristics of the solenoid valve (for example, the relationship between the current value applied to the drive unit and the pressure of the pressure oil output from the solenoid valve). Is. Therefore, in order to accurately realize the desired characteristics of the solenoid valve, high processing accuracy is required to form the housing spaces having different diameters in a single sleeve. However, such highly accurate processing requires strict processing control and is not easy. Further, when changing the characteristics of the solenoid valve, it is necessary to change the characteristics of the accommodation space (for example, the relative relationship of the diameters between the accommodation spaces) together with the characteristics of the spool. Therefore, in order to cope with various characteristics of the solenoid valve, a sleeve having a storage space corresponding to each characteristic is required. Therefore, as the number of required solenoid valve characteristics increases, the number of sleeves that need to be prepared increases. It is very burdensome to process and prepare a large number of sleeves having different characteristics.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique that allows a sleeve to have a plurality of housing spaces having different diameters easily and highly accurately in a solenoid valve. .. Alternatively, it is an object of the present invention to provide a technique that makes it possible to easily and flexibly realize a solenoid valve having various characteristics.

One aspect of the present invention includes a valve main body portion, a spool having a large diameter portion and a small diameter portion having different outer diameters, and a main body accommodating space in which a part of the spool is positioned, and slidably supporting the spool. The sleeve division which is fixed between the valve body and the valve body and the sleeve body, and which has the divided accommodation space in which the large diameter portion or the small diameter portion of the spool is located and slidably supports the spool. The present invention relates to an electromagnetic valve including a section and a drive section that drives a spool.

The divided storage space may be located closer to the drive unit than the main body storage space.

The spool is driven by the drive unit to move in the axial direction, and the sleeve main body has a portion that is radially formed on the side opposite to the drive unit via the spool and covers at least a part of the main body accommodation space. You may.

The sleeve dividing portion may slidably support the small diameter portion of the spool.

The sleeve dividing portion may slidably support the large diameter portion of the spool.

Another aspect of the present invention relates to a directional control valve including the above solenoid valve.

Another aspect of the present invention relates to a construction machine including the above-described directional control valve.

According to the present invention, in the solenoid valve, it is possible to easily and accurately provide the sleeve with a plurality of housing spaces having different diameters. Further, according to the present invention, it is possible to easily and flexibly realize a solenoid valve having various characteristics.

FIG. 1 is a sectional view showing a schematic configuration of a positive type solenoid valve. FIG. 2 is a sectional view showing a schematic configuration of a negative type solenoid valve. FIG. 3 is a diagram showing a specific example of a positive type solenoid valve (electromagnetic proportional valve), and is a diagram showing a cross section of the solenoid valve as viewed from the side. FIG. 4 is a view showing a specific example of a negative type solenoid valve (electromagnetic proportional valve), and is a view of a cross section of the solenoid valve as seen from the side. FIG. 5 is a sectional view showing an example of the directional control valve. FIG. 6 is an external view showing the outline of a typical configuration example of a hydraulic excavator.

Embodiments of the present invention will be described below with reference to the drawings.

There are positive type solenoid valves and negative type solenoid valves in solenoid valves (especially solenoid proportional valves). A solenoid valve whose output pressure oil pressure (that is, oil pressure) increases as the excitation current applied to the drive unit increases is classified as a positive type solenoid valve, and the output pressure oil pressure decreases. Is classified as a negative type solenoid valve.

The present invention is applicable to both positive type solenoid valves and negative type solenoid valves. Below, the schematic structure of a positive type solenoid valve and a negative type solenoid valve is demonstrated first, and the concrete structure example of a positive type solenoid valve and a negative type solenoid valve is demonstrated after that.

[Schematic structure of solenoid valve]
FIG. 1 is a cross-sectional view showing a schematic configuration of a positive type solenoid valve 10. FIG. 2 is a cross-sectional view showing a schematic configuration of the negative type solenoid valve 10. Each element shown in FIGS. 1 and 2 is conceptually illustrated, and the shape, size, etc. of each element are not limited to the shape, size, etc. shown in FIGS.

Each of the electromagnetic valves 10 shown in FIGS. 1 and 2 includes a valve body 11, a drive unit 12, a spool 13, and a sleeve 14.

The valve body 11 supports the drive unit 12, the spool 13 and the sleeve 14. In the solenoid valve 10 shown in FIGS. 1 and 2, the drive unit 12 is attached to the valve main body 11 via a connecting member (not shown). The sleeve 14 (particularly the sleeve body portion 15) is fixed to the valve body portion 11 by being sandwiched between a fastener 31 (for example, a C-shaped retaining ring) that acts as a stopper and the valve body portion 11. The spool 13 is slidably held by the sleeve 14 while being located in the accommodation space of the sleeve 14, and is supported by the valve body 11 via the sleeve 14. However, the valve body 11 may support the drive unit 12, the spool 13, and the sleeve 14 by another support mode.

The drive unit 12 is fixed to the valve body unit 11 and drives the spool 13. The illustrated drive unit 12 includes a solenoid unit 20 and a plunger (movable iron core) 21. The solenoid portion 20 and the plunger 21 are covered and surrounded by the housing portion of the valve body portion 11. The solenoid unit 20 is a magnetic force generation device that generates a magnetic force according to an applied current, and is composed of a solenoid coil. The position of the plunger 21 in the axial direction D1 is changed according to the current applied to the solenoid portion 20, and the movement amount of the plunger 21 from the solenoid portion 20 is changed. The plunger 21 is located on the central axis (not shown) of the solenoid valve 10 extending in the axial direction D1, and is provided so as to be reciprocally movable in the axial direction D1 under the influence of the magnetic force from the solenoid portion 20. Thus, the axial direction D1 corresponds to the direction in which the plunger 21 moves.

Plunger 21 acting as a drive rod may be configured by a single member or may be configured by combining a plurality of members. When the plunger 21 is composed of a single member, the plunger 21 affected by the magnetic force from the solenoid portion 20 can directly contact the spool 13. When the plunger 21 is composed of a plurality of members, the member that is directly affected by the magnetic force from the solenoid portion 20 and the member that contacts the spool 13 can be different. In this case, the member of the plunger 21 that comes into contact with the spool 13 can move to the spool 13 side by receiving a force from the member of the plunger 21 that is directly affected by the magnetic force from the solenoid portion 20. ..

The specific configurations of the solenoid unit 20 and the plunger 21 are not limited. The drive unit 12 may employ a method of operating the plunger 21 mainly by the magnetic force provided by the solenoid unit 20 (so-called pull-type drive method). The drive unit 12 may employ a method of operating the plunger 21 according to the balance between the magnetic force provided by the solenoid unit 20 and the physical force applied from the push bar (so-called push type drive method).

The current passed through the solenoid unit 20 is controlled by a control unit (not shown). The control unit is connected to an operation unit (for example, an operation lever unit, an operation panel, etc.) that is directly operated by an operator of a hydraulic device (for example, a working machine such as a construction machine) on which the solenoid valve 10 is mounted. The operation command signal corresponding to the state of the operation unit is input from the operation unit. The control unit controls the current flowing through the solenoid unit 20 according to an operation command signal input by the operator via the operation unit. In this way, the operation of the drive unit 12 (that is, the position of the plunger 21) is controlled by the control unit, and the drive unit 12 changes the structure of the flow path of the solenoid valve 10.

The spool 13 is located on the central axis (not shown) of the solenoid valve 10 extending in the axial direction D1, and is provided so as to be capable of reciprocating in the axial direction D1 depending on the magnitude of the force received from the plunger 21. The spool 13 has a large diameter portion 23 and a small diameter portion 24. The large diameter portion 23 and the small diameter portion 24 have different outer diameters in the radial direction D2 that is perpendicular to the axial direction D1. The large diameter portion 23 has a relatively large outer diameter, and the small diameter portion 24 is relatively large. Has a relatively small outer diameter. In the solenoid valve 10 shown in FIG. 1, the small diameter portion 24 is located closer to the drive portion 12 side (the upper side in the drawing) than the large diameter portion 23. On the other hand, in the solenoid valve 10 shown in FIG. 2, the large diameter portion 23 is located closer to the drive portion 12 side than the small diameter portion 24. The large diameter portion 23 and the small diameter portion 24 shown in FIGS. 1 and 2 are adjacent to each other in the axial direction D1, but the large diameter portion 23 and the small diameter portion 24 do not necessarily have to be adjacent to each other. The spool 13 may have three or more portions having different outer diameters, or the outer diameter may change at two or more locations in the axial direction D1.

The spool 13 has a first flow path C1 extending in the axial direction D1, and a second flow path C2 and a third flow path C3 extending in the radial direction D2. The first flow path C1 penetrates the spool 13 and exists over the entire large diameter portion 23 and the small diameter portion 24. The second flow path C2 and the third flow path C3 are connected to the first flow path C1 and open toward the sleeve 14 (particularly the sleeve body 15). In the solenoid valve 10 shown in FIG. 1, the second flow passage C2 and the third flow passage C3 are provided in the large diameter portion 23. In the solenoid valve 10 shown in FIG. 2, the second flow passage C2 and the third flow passage C3 are provided in the small diameter portion 24. The first flow path C1 is a flow path for mainly sending and receiving pressure oil to and from the actuator A. The second flow path C2 is a flow path for mainly discharging the pressure oil from the first flow path C1 toward the tank T. The third flow path C3 is a flow path for mainly supplying the pressure oil from the pump P to the first flow path C1.

The position of the spool 13 in the radial direction D2 is regulated by the sleeve 14. On the other hand, with respect to the axial direction D1, the spool 13 is movably provided in the axial direction D1 in a housing space (a main body housing space 25 and a split housing space 26 described later) of the sleeve 14. The spool 13 receives pressure oil supplied from the pump P to the electromagnetic valve 10, the plunger 21 of the drive unit 12, and the force in the axial direction D1 from the compression spring 17, and is arranged at a position where the forces received from these elements are balanced. It Depending on the position of the spool 13 in the sleeve 14, the flow path of the spool 13 (in particular, the second flow path C2 and the third flow path C3) and the flow path of the sleeve 14 (in particular, the fourth flow path of the sleeve body 15). The connection and non-connection with the flow path C4 and the fifth flow path C5) are switched, and the flow path configuration of the solenoid valve 10 is determined.

The sleeve 14 has a sleeve main body portion 15 and a sleeve division portion 16, and the sleeve main body portion 15 and the sleeve division portion 16 are respectively constituted by separate members.

The sleeve body 15 is fixed to the valve body 11. The sleeve body 15 shown in FIGS. 1 and 2 is hooked on a fastener 31 fixedly provided in the valve body 11. The sleeve body 15 has a body housing space 25 in which a part of the spool 13 is located, and slidably supports the spool 13.

In the solenoid valve 10 shown in FIG. 1, the large diameter portion 23 of the spool 13 is located in the main body accommodation space 25. The diameter of the main body housing space 25 in the radial direction D2 (hereinafter, also simply referred to as “diameter”) corresponds to the outer diameter of the large-diameter portion 23 in the radial direction D2 (hereinafter, also simply referred to as “outer diameter”). That is, the size of the diameter of the main body accommodation space 25 is exactly the same as or very close to the size of the outer diameter of the large diameter portion 23. For example, the diameter of the main body accommodation space 25 is slightly smaller than the outer diameter of the large diameter portion 23. May be large. Accordingly, the spool 13 can move in the axial direction D1 without the pressure oil basically flowing between the large diameter portion 23 and the sleeve body portion 15. As described above, the sleeve body portion 15 shown in FIG. 1 supports the large diameter portion 23, and the large diameter portion 23 slides in the axial direction D1 along the inner wall surface of the sleeve body portion 15 that defines the body housing space 25. You can

Although the main body housing space 25 shown in FIG. 1 has a diameter corresponding to the outer diameter of the large diameter portion 23, only a part of the main body housing space 25 including the moving range of the large diameter portion 23 is used. , May have a diameter corresponding to the outer diameter of the large diameter portion 23.

A part of the small diameter portion 24 of the spool 13 is also arranged in the main body accommodation space 25 shown in FIG. As described above, since the main body housing space 25 has a diameter corresponding to the large diameter portion 23 of the spool 13, there is a space (hereinafter, also referred to as “drain space”) between the small diameter portion 24 of the spool 13 and the sleeve main body portion 15. S) is formed. The drain space S is surrounded by the spool 13 and the sleeve 14, and is connected to the drain D via the sixth flow path C6 included in the sleeve body 15. Regardless of the drive position of the spool 13, the pressure oil in the drain space S is discharged to the drain D via the sixth flow path C6. Therefore, while the spool 13 is being driven in the axial direction D1 by the drive unit 12, the portion of the spool 13 that faces the drain space S (that is, the portion that defines the drain space S) basically receives the force from the pressure oil. It is zero. Since both the drain D and the tank T are elements that receive the pressure oil discharged from the solenoid valve 10, they may be provided separately from each other, or both the drain D and the tank T may be provided by a common element. May be configured.

On the other hand, in the solenoid valve 10 shown in FIG. 2, the small diameter portion 24 of the spool 13 is arranged in the main body accommodation space 25, and the sleeve main body portion 15 supports the small diameter portion 24. The small diameter portion 24 can slide in the axial direction D1 along the inner wall surface of the sleeve main body portion 15 that defines the main body accommodation space 25. The large-diameter portion 23 of the sleeve main body 15 is also partially arranged in the main body accommodation space 25 shown in FIG.

As described above, the main body accommodating space 25 shown in FIG. 2 includes the large diameter accommodating space 25a and the small diameter accommodating space 25b having different sizes (ie, diameters) in the radial direction D2. The diameter of the small diameter accommodation space 25b strictly corresponds to the outer diameter of the small diameter portion 24 of the spool 13. Therefore, basically, the pressure oil does not flow between the spool 13 (especially the small diameter portion 24) and the sleeve main body portion 15 in the small diameter accommodation space 25b, and the spool 13 can move in the axial direction D1. On the other hand, the diameter of the large-diameter storage space 25a may or may not correspond exactly to the outer diameter of the large-diameter portion 23 of the spool 13. The large-diameter storage space 25a may have a diameter such that the movement of the spool 13 in the axial direction D1 in the large-diameter storage space 25a is not hindered by the sleeve body portion 15, and is larger than the outer diameter of the large-diameter portion 23. Can have a diameter of

The sleeve body portion 15 shown in each of FIGS. 1 and 2 has a bottom portion 28 (that is, an extension portion) extending in the radial direction D2 on the side opposite to the drive portion 12 via the spool 13 in the axial direction D1. The bottom portion 28 formed in the radial direction D2 constitutes a portion that covers at least a part of the main body accommodation space 25. The bottom portion 28 shown in each of FIGS. 1 and 2 partially covers the main body housing space 25 and has a through hole 29. The bottom portion 28 functions as a seating portion for the compression spring 17, and also functions as a stopper that prevents the compression spring 17 and the spool 13 from falling off the sleeve body portion 15 in the axial direction D1. The through hole 29 functions as an actuator port, and when the solenoid valve 10 is attached to another device, the through hole 29 is connected to the port and the flow path of the other device. The diameter of the through hole 29 shown in FIG. 1 is smaller than the outer diameter of the large diameter portion 23 of the spool 13 and smaller than the size of the compression spring 17 in the radial direction D2 (particularly the outer diameter size). The diameter of the through hole 29 shown in FIG. 2 is smaller than the outer diameter of the small diameter portion 24 of the spool 13 and smaller than the size of the compression spring 17 in the radial direction D2 (particularly the outer diameter size).

The compression spring 17 is located in the seventh flow path C7 that is formed by the portion between the bottom portion 28 of the main body housing space 25 and the spool 13, is sandwiched by the bottom portion 28 and the spool 13, and is in the axial direction D1. It is compressed to. The size of the seventh flow path C7 in the axial direction D1 changes depending on the position of the spool 13 in the axial direction D1, and the force (elastic force) applied to the spool 13 from the compression spring 17 changes. The seventh flow path C7 is connected to the first flow path C1 and the through hole 29. Therefore, the pressure oil of the first flow path C1 is supplied to the actuator A via the seventh flow path C7 and the through hole 29, and the pressure oil of the actuator A is supplied to the actuator A via the through hole 29 and the seventh flow path C7. It is returned to the first flow path C1.

The sleeve dividing portion 16 is sandwiched between the valve body portion 11 and the sleeve body portion 15 in the axial direction D1, and is fixed between the valve body portion 11 and the sleeve body portion 15. The sleeve division 16 shown in each of FIGS. 1 and 2 is fixed to the sleeve body 15. The sleeve division portion 16 has a division accommodation space 26 formed by a through hole extending in the axial direction D1. The divided accommodating space 26 is located closer to the drive unit 12 than the main body accommodating space 25 and is connected to the main body accommodating space 25. The illustrated sleeve division portion 16 has a tubular shape having a ring-shaped cross section, and is fitted into a concave seating portion 15 a forming an end portion of the sleeve body portion 15. An O-ring R is arranged between the sleeve division 16 and the valve body 11. The O-ring R is sandwiched between the sleeve dividing portion 16 and the valve body portion 11 and compressed in the radial direction D2, and liquid-tightly seals between the sleeve dividing portion 16 and the valve body portion 11.

The diameter of the seating portion 15a may exactly correspond to the outer diameter of the sleeve dividing portion 16, but may not strictly correspond to it. When the diameter of the seat portion 15a corresponds exactly to the outer diameter of the sleeve split portion 16, the seat portion 15a determines the position of the sleeve split portion 16 in the radial direction D2. On the other hand, when the diameter of the seating portion 15 a does not correspond exactly to the outer diameter of the sleeve dividing portion 16, the O-ring R located between the valve body 11 and the sleeve dividing portion 16 is The position in the radial direction D2 is determined. In this way, the sleeve division portion 16 is arranged at a desired position by the sleeve body portion 15 (particularly the seat portion 15a) or the O-ring R, and is fixed to the valve body portion 11 and the sleeve body portion 15.

A part of the spool 13 (particularly the large diameter portion 23 or the small diameter portion 24) is located in the divided accommodation space 26. The diameter of the divided accommodation space 26 corresponds to the outer diameter of the large diameter portion 23 or the small diameter portion 24 of the spool 13 arranged in the divided accommodation space 26. Specifically, the diameter of the divided storage space 26 shown in FIG. 1 corresponds to the outer diameter of the small diameter portion 24 of the spool 13. The diameter of the divided accommodation space 26 shown in FIG. 2 corresponds to the outer diameter of the large diameter portion 23 of the spool 13. Therefore, the spool 13 can move in the axial direction D1 basically without the pressure oil flowing between the sleeve dividing portion 16 and the spool 13 in the divided housing space 26.

In this way, the sleeve dividing portion 16 supports the portion of the spool 13 arranged in the divided accommodating space 26 slidably in the axial direction D1. The small-diameter portion 24 of the spool 13 is partially arranged in the divided accommodating space 26 shown in FIG. 1, and the sleeve dividing portion 16 slidably supports the small-diameter portion 24 of the spool 13. On the other hand, the large-diameter portion 23 of the spool 13 is partially arranged in the divided accommodating space 26 shown in FIG. 2, and the sleeve dividing portion 16 slidably supports the large-diameter portion 23 of the spool 13.

By configuring the sleeve 14 by combining a plurality of members as described above, it is possible to realize a storage space that strictly corresponds to the outer diameter of each of the large diameter portion 23 and the small diameter portion 24 of the spool 13 by separate members. You can That is, the diameter of the main body accommodation space 25 formed in the sleeve main body portion 15 may exactly correspond to only the outer diameter of one of the large diameter portion 23 and the small diameter portion 24. Further, the diameter of the divided accommodating space 26 formed in the sleeve dividing portion 16 may exactly correspond to only the outer diameter of the other of the large diameter portion 23 and the small diameter portion 24. Therefore, compared with the case where the two accommodation spaces formed in a single sleeve are made to correspond exactly to the outer diameters of the large diameter portion 23 and the small diameter portion 24 of the spool 13, the accommodation space for the sleeve 14 is formed. Can be simplified.

For example, in the positive type solenoid valve 10 shown in FIG. 1, the main body accommodation space 25 of the sleeve main body portion 15 is made to correspond to the large diameter portion 23 of the spool 13, and the divided accommodation space 26 of the sleeve dividing portion 16 is changed to the small diameter portion 24. It suffices that they correspond to each other, and it is not necessary to form a step portion that is strictly aligned on the sleeve main body portion 15. Further, in the negative type solenoid valve 10 shown in FIG. 2, the main body accommodation space 25 (particularly the small diameter accommodation space 25b) of the sleeve main body portion 15 is made to correspond to the small diameter portion 24 of the spool 13, and the divided accommodation space 26 of the sleeve division portion 16 is provided. May correspond to the large diameter portion 23 of the spool 13. The sleeve body 15 shown in FIG. 2 has not only the small-diameter housing space 25b but also the large-diameter housing space 25a. However, the diameter of the large-diameter housing space 25a is not always strictly equal to the outer diameter of the large-diameter portion 23 of the spool 13. It does not have to correspond. Therefore, in order to form the large-diameter storage space 25a in the sleeve body 15, a high degree of processing accuracy is not always required. Similarly, the sleeve main body 15 shown in FIGS. 1 and 2 has the seating portion 15a, but as described above, the diameter of the seating portion 15a does not necessarily strictly correspond to the outer diameter of the sleeve dividing portion 16. Absent.

Further, in the solenoid valve 10 shown in FIGS. 1 and 2, the large diameter portion 23 and the small diameter portion 24 of the spool 13 are slidably supported by separate members (namely, the sleeve main body portion 15 and the sleeve dividing portion 16). Therefore, by changing the combination of the sleeve main body portion 15 and the sleeve dividing portion 16, it is possible to flexibly deal with various spools 13 having different relative relationships of the outer diameters of the large diameter portion 23 and the small diameter portion 24.

In particular, by using one of the sleeve body 15 and the sleeve division 16 in common, and changing only the other, the size ratio of the large diameter portion 23 and the small diameter portion 24 (especially the ratio of the areas spread in the radial direction D2). It is possible to deal with various spools 13 of different ). For example, it is possible to easily realize various electromagnetic valves 10 having different characteristics by changing only the sleeve dividing portion 16 (particularly the diameter of the divided accommodating space 26) while commonly using the sleeve main body portion 15. When the sleeve main body 15 is commonly used as described above, the solenoid valve 10 having desired characteristics can be quickly and easily prepared by preparing a plurality of sleeve divisions 16 corresponding to a plurality of assumed characteristics. It is possible to make Particularly, as in the solenoid valve 10 shown in FIGS. 1 and 2, by making the size of the sleeve dividing portion 16 smaller than the size of the sleeve main body portion 15, it is possible to reduce the labor required for processing the divided accommodation space 26. The storage space for the plurality of sleeve divisions 16 can be reduced.

In this way, by constructing the sleeve 14 by combining a plurality of members, it is possible to easily and flexibly realize the solenoid valve 10 having various characteristics, and to provide a dedicated single sleeve that requires high processing accuracy. No need to make and prepare.

Further, since the sleeve 14 (particularly the sleeve main body portion 15) integrally has the bottom portion 28 (extension portion) extending in the radial direction D2, it is not necessary to separately provide a lid member for preventing the compression spring 17 and the spool 13 from falling off. .. Therefore, it is not necessary to attach such a lid member to the sleeve 14, and the compression spring 17 and the spool 13 are simply inserted from one side into the main body accommodating space 25 of the sleeve main body portion 15. The compression spring 17 can be assembled properly. By thus forming the bottom portion 28 with a part of the sleeve main body portion 15, it is possible to reliably prevent the compression spring 17 and the spool 13 from falling off while simplifying the configuration of the sleeve 14, and the assembly is also easy.

If the sleeve 14 is not provided with the bottom portion 28 (extension portion), it is necessary to attach a lid member to the end portion of the sleeve 14 in order to prevent the compression spring 17 and the spool 13 from falling off. Such a lid member is securely attached to the sleeve 14 and cannot be easily removed from the sleeve body 15. However, there is a possibility that the lid member is loosely fixed to the sleeve 14 with the lapse of the use period, and the lid member receives a force from the compression spring 17. Therefore, the possibility that the lid member will fall off the sleeve 14 is very small, but not zero. On the other hand, in the solenoid valve 10 shown in FIGS. 1 and 2, the bottom portion 28 (extension portion) formed by a part of the sleeve body portion 15 substantially acts as a lid member, so that the compression spring 17 and the spool 13 are prevented from falling off. There is no concern.

[Detailed specific example of solenoid valve]
FIG. 3 is a diagram showing a specific example of the positive type solenoid valve (electromagnetic proportional valve) 10 and is a diagram showing a cross section of the solenoid valve as viewed from the side. In the solenoid valve 10 shown in FIG. 3, the same or similar elements as those of the solenoid valve 10 shown in FIG. 1 described above are denoted by the same reference numerals, and detailed description thereof will be omitted. Further, in order to reduce complexity, hatching showing a cross section is not shown in FIG.

The valve main body 11 shown in FIG. 3 has a main body mounting portion 41, a flange portion 42, and a housing portion 43. The body mounting portion 41, the flange portion 42, and the housing portion 43 are fixed to each other by fixing means (not shown).

The fastener 31 is fixedly attached to the main body attachment portion 41. The sleeve main body portion 15 is sandwiched by the main body attaching portion 41 and the fastener 31 in the axial direction D1 and is fixed to the main body attaching portion 41. The sleeve dividing portion 16 is sandwiched in the axial direction D1 by the body mounting portion 41 and the sleeve body portion 15, and is fixed to the body mounting portion 41. An O-ring R is provided between each of the sleeve main body portion 15 and the sleeve division portion 16 and the main body attachment portion 41. With the O ring R, each of the sleeve main body portion 15 and the sleeve division portion 16 and the main body attachment portion are attached. The part 41 and the part 41 are liquid-tightly sealed.

The flange portion 42 functions as a joint. When the solenoid valve 10 is attached to another device, the flange portion 42 is fixed to the other device via a fixture such as a screw. The housing part 43 surrounds the solenoid part 20 (not shown in FIG. 3) of the drive part 12.

The spool 13 has a large diameter portion 23 and a small diameter portion 24, and the small diameter portion 24 has a first small diameter portion 24a and a second small diameter portion 24b. The first small diameter portion 24a constitutes an end portion of the spool 13 on the drive portion 12 side, and the second small diameter portion 24b is located between the first small diameter portion 24a and the large diameter portion 23, and the second small diameter portion 24b of the second small diameter portion 24b. The outer diameter is smaller than the outer diameter of the first small diameter portion 24a. The outer diameter of the first small diameter portion 24a corresponds to the inner diameter of the sleeve divided portion 16 (that is, the diameter of the divided accommodation space 26), and at least a part of the first small diameter portion 24a is slidably supported by the sleeve divided portion 16. Has been done. Therefore, basically, the pressure oil does not flow between the sleeve division portion 16 and the spool 13 (particularly the first small diameter portion 24a) in the divided accommodation space 26, and the spool 13 can move in the axial direction D1.

The main body accommodation space 25 includes a plurality of spaces having different diameters (that is, sizes in the radial direction D2). The diameter of the space (hereinafter, also referred to as “large diameter support space 25c”) including at least a part of the movable range of the large diameter portion 23 of the spool 13 among the plurality of spaces forming the main body accommodation space 25 is , Corresponding to the outer diameter of the large diameter portion 23. Therefore, at least a part of the large diameter portion 23 is slidably supported by the sleeve body 15. In addition, the spool 13 can move in the axial direction D1 basically without pressure oil flowing between the sleeve body 15 and the spool 13 (particularly the large diameter portion 23) in the large diameter support space 25c.

A plurality of O-rings R are provided on the outer peripheral portion of the sleeve body 15. These O-rings R liquid-tightly seal between the solenoid valve 10 and another device when the solenoid valve 10 is attached to another device.

The basic structure of the other elements of the solenoid valve 10 shown in FIG. 3 is the same as the basic structure of the corresponding elements shown in FIG. The specific shape and size of each element forming the solenoid valve 10 shown in FIG. 3 is different from the specific shape and size of each element forming the solenoid valve 10 shown in FIG. However, most of the relative positional relationship between each element and the basic configuration of each element are common between the solenoid valve 10 shown in FIG. 3 and the solenoid valve 10 shown in FIG.

FIG. 4 is a view showing a specific example of the negative type solenoid valve (electromagnetic proportional valve) 10 and is a view of a cross section of the solenoid valve as seen from the side. In the solenoid valve 10 shown in FIG. 4, the same or similar elements as those of the solenoid valve 10 shown in FIG. 2 and the solenoid valve 10 shown in FIG. Detailed description is omitted. Further, in order to reduce complexity, hatching showing a cross section is not shown in FIG.

The valve body 11 shown in FIG. 4 has a body mounting portion 41, a flange portion 42, and a housing portion 43 that are similar to the valve body portion 11 shown in FIG.

The spool 13 shown in FIG. 4 has a large diameter portion 23 and a small diameter portion 24, and the small diameter portion 24 has a first small diameter portion 24a and a second small diameter portion 24b. The first small diameter portion 24a is located closer to the compression spring 17 side (that is, the bottom portion 28 side) than the large diameter portion 23 and the second small diameter portion 24b, and the second small diameter portion 24b is the large diameter portion 23 and the first small diameter portion. It is located between 24a. The outer diameter of the large diameter portion 23 corresponds to the inner diameter of the sleeve dividing portion 16 (that is, the diameter of the divided accommodation space 26), and at least a part of the large diameter portion 23 is slidably supported by the sleeve dividing portion 16. There is. Therefore, basically, the pressure oil does not flow between the sleeve division portion 16 and the spool 13 (particularly, the large diameter portion 23) in the divided accommodation space 26, and the spool 13 can move in the axial direction D1. The outer diameter of the second small diameter portion 24b is smaller than the outer diameter of the first small diameter portion 24a.

The main body accommodation space 25 includes a plurality of spaces having different sizes (that is, diameters) in the radial direction D2. The diameter of the space (hereinafter, also referred to as “small diameter support space 25d”) including at least a part of the movable range of the first small diameter portion 24a of the spool 13 among the plurality of spaces forming the main body housing space 25 is , Corresponding to the outer diameter of the first small diameter portion 24a. Therefore, at least a part of the first small diameter portion 24a is slidably supported by the sleeve main body portion 15. Further, in the small diameter support space 25d, basically, the pressure oil does not flow between the sleeve body 15 and the spool 13 (particularly the first small diameter portion 24a), and the spool 13 can move in the axial direction D1.

In the solenoid valve 10 shown in FIGS. 3 and 4 having the above-described configuration, the magnitude of the electric current applied to the solenoid portion 20 is controlled to adjust the position of the plunger 21 in the axial direction D1, and to adjust the axial direction of the spool 13 in the axial direction D1. The position can be changed. The connection state of the pump P and the tank T with respect to the first flow path C1 is changed according to the position of the spool 13, and is supplied to the actuator A from the first flow path C1 through the seventh flow path C7 and the through hole 29. The pressure of the pressure oil can be changed.

For example, the position of the spool 13 can be adjusted so that the third flow path C3 is connected to the fifth flow path C5 while blocking the second flow path C2 from the fourth flow path C4. In this case, the pressure oil is supplied from the pump P to the first flow path C1 via the fifth flow path C5 and the third flow path C3, and the pressure oil is not discharged from the first flow path C1 to the tank T. Therefore, the pressure of the pressure oil supplied from the first flow path C1 to the actuator A gradually rises, and the high pressure oil can be supplied to the actuator A. On the other hand, the position of the spool 13 can be adjusted so that the third flow path C3 is blocked from the fifth flow path C5 while connecting the second flow path C2 to the fourth flow path C4. In this case, the pressure oil is not supplied from the pump P to the first flow path C1, and the pressure oil in the first flow path C1 is discharged to the tank T via the second flow path C2 and the fourth flow path C4. Therefore, the pressure of the pressure oil supplied from the first flow path C1 to the actuator A gradually decreases and finally becomes zero.

[Application example]
The solenoid valve 10 described above can be mounted on various devices (for example, a hydraulic device). For example, the direction switching valve may include the solenoid valve 10 described above. Further, construction machines such as hydraulic excavators and other work machines may include a directional control valve including the solenoid valve 10 described above.

[Direction switching valve]
FIG. 5 is a sectional view showing an example of the direction switching valve 90. The directional control valve 90 shown in FIG. 5 has a known structure, and the specific configuration and operation of the directional control valve 90 shown in FIG. 5 can be easily understood by referring to, for example, Japanese Patent Application Laid-Open No. 08-170353. can do. Therefore, in this specification, detailed description of the directional control valve 90 shown in FIG. 5 is omitted.

In the directional control valve 90 shown in FIG. 5, according to the position of the directional control spool 91 in the spool hole 96 of the valve block 95 (that is, the position in the left-right direction in FIG. 5), the flow path of the valve block 95 (particularly the first load) The flow and flow direction of the hydraulic oil in the passage 92 and the second load passage 93) are changed. For example, changing the position of the direction switching spool 91 with respect to the valve block 95 in a state where the first load passage 92 and the second load passage 93 are connected to a common hydraulic device (for example, a hydraulic motor, a hydraulic piston, etc.). By this, not only can the supply and discharge of the hydraulic oil to the hydraulic device be switched, but the drive state of the hydraulic device can also be switched between forward drive and reverse drive.

The position of the direction switching spool 91 is determined by the balance of pilot pressure applied to both ends of the direction switching spool 91. A first pilot pressure introducing section 98 and a second pilot pressure introducing section 99 are attached to a valve block 95 of the illustrated directional control valve 90. Inside the first pilot pressure introducing portion 98, a drive elastic body 94 composed of a compression spring or the like is provided. The drive elastic body 94 is compressed by receiving a force from the first pilot pressure introducing portion 98 and the direction switching spool 91. The pressure of the pressure oil supplied to the first pilot pressure introducing portion 98 and the elastic force of the drive elastic body 94 are applied to one end (the right end in FIG. 5) of the direction switching spool 91. .. The pressure of the pressure oil supplied to the second pilot pressure introducing portion 99 is applied to the other end portion (the end portion on the left side in FIG. 5) of the direction switching spool 91.

Therefore, by attaching the above-mentioned solenoid valve 10 to at least one of the first pilot pressure introducing portion 98 and the second pilot pressure introducing portion 99 and electrically controlling the solenoid valve 10, the direction switching spool 91 is provided. It is possible to adjust the position of. That is, the pressure of the pressure oil supplied to the first pilot pressure introducing portion 98 and/or the second pilot pressure introducing portion 99 via the through hole 29 (actuator port) of the solenoid valve 10 is changed by the direction switching spool 91. By utilizing the pilot pressure for moving, the direction switching spool 91 can be arranged at a desired position in the spool hole 96. When the solenoid valve 10 is attached to only one of the first pilot pressure introducing portion 98 and the second pilot pressure introducing portion 99, the other introducing portion to which the solenoid valve 10 is not attached is provided with a normal pipe. It is possible to introduce pressure oil, which provides pilot pressure.

The directional switching valve that can mount the solenoid valve 10 described above is not limited to the directional switching valve 90 shown in FIG. Further, the solenoid valve 10 can be mounted on hydraulic equipment other than the direction switching valve and other equipment.

[Hydraulic excavator]
FIG. 6 is an external view schematically showing a typical configuration example of the hydraulic excavator 110. The hydraulic excavator 110 generally includes a lower frame 144 including a crawler, an upper frame 145 pivotally provided with respect to the lower frame 144, a boom 147 attached to the upper frame 145, and an arm 148 attached to the boom 147. , A bucket 149 attached to the arm 148. Hydraulic cylinders 167, 168, and 169 as actuators are boom, arm, and bucket hydraulic cylinders, and drive the boom 147, arm 148, and bucket 149, respectively. The rotation driving force from the turning motor 146 is transmitted to the upper frame 145 so that the turning motor 146 turns the upper frame 145. Further, the rotational driving force from the traveling motor 151 is transmitted to the crawlers of the lower frame 144 so that the traveling motor 151 drives the crawler and the hydraulic excavator 110 travels.

In this hydraulic excavator 110, for example, the direction switching including the solenoid valve 10 described above is provided at an appropriate position in an oil passage included in or connected to the hydraulic cylinders 167, 168, 169, the swing motor 146, and/or the traveling motor 151. The valve 90 may be installed.

The present invention is not limited to the above embodiments and modifications. For example, various modifications may be added to each element of the above-described embodiment and modification, or the embodiment and modification may be partially combined. Further, the effect produced by the present invention is not limited to the above-described effect, and a unique effect according to a specific configuration is exhibited.

10 solenoid valve, 11 valve body part, 12 drive part, 13 spool, 14 sleeve, 15 sleeve body part, 15a seating part, 16 sleeve dividing part, 17 compression spring, 20 solenoid part, 21 plunger, 23 large diameter part, 24 small diameter portion, 24a first small diameter portion, 24b second small diameter portion, 25 main body accommodation space, 25a large diameter accommodation space, 25b small diameter accommodation space, 25c large diameter support space, 25d small diameter support space, 26 split accommodation space, 28 bottom portion , 29 through holes, 31 fasteners, 41 main body mounting portion, 42 flange portion, 43 housing portion, 90 directional switching valve, 91 directional switching spool, 92 first load passage, 93 second load passage, 94 drive elastic body, 95 Valve block, 96 spool hole, 98 1st pilot pressure introducing part, 99 2nd pilot pressure introducing part, 110 hydraulic excavator, 144 lower frame, 145 upper frame, 146 swing motor, 147 boom, 148 arm, 149 bucket, 151 traveling Motor, 167 hydraulic cylinder, 168 hydraulic cylinder, 169 hydraulic cylinder, A actuator, C1 first flow path, C2 second flow path, C3 third flow path, C4 fourth flow path, C5 fifth flow path, C6 sixth Flow path, C7 7th flow path, D drain, D1 axial direction, D2 radial direction, P pump, R O ring, S drain space, T tank

Claims (7)

The valve body,
A spool having a large diameter portion and a small diameter portion whose outer diameters are different from each other,
A sleeve main body having a main body housing space in which a part of the spool is located, and slidably supporting the spool;
A sleeve dividing portion which is fixed between the valve body portion and the sleeve body portion, has a split accommodation space in which the large diameter portion or the small diameter portion of the spool is located, and which slidably supports the spool. When,
And a drive unit that drives the spool. The solenoid valve according to claim 1, wherein the divided accommodating space is located closer to the drive unit than the main body accommodating space. The spool is driven by the drive unit to move in the axial direction,
The solenoid valve according to claim 1 or 2, wherein the sleeve main body portion has a portion that is formed in the radial direction on the side opposite to the drive portion via the spool and covers at least a part of the main body accommodation space. The solenoid valve according to any one of claims 1 to 3, wherein the sleeve dividing portion slidably supports the small diameter portion of the spool. The solenoid valve according to any one of claims 1 to 3, wherein the sleeve dividing portion slidably supports the large diameter portion of the spool. A directional control valve comprising the solenoid valve according to claim 1. A construction machine comprising the directional control valve according to claim 6.

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