KR20210033921A - Valve and construction machine - Google Patents

Abstract

The present invention relating to a valve comprises: a container-shaped body unit having an outer circumferential surface and a central shaft formed in an axial line direction; a valve body provided to one end of the axial line direction of the body unit and having an end tapered unit of which a diameter gets smaller toward one side of the axial line direction; and a housing having a flow passage of fluid and a storage space storing the valve body. The housing comes in contact with the end tapered unit to block the flow passage and comes in contact with the outer circumferential surface of the body unit, thereby guiding the body unit in the axial line direction.

Description

Valve and construction machinery {VALVE AND CONSTRUCTION MACHINE}

The present invention relates to a valve and a construction machine.

Conventionally, a hydraulic crane is known as one type of construction machinery. A hydraulic crane is provided with a boom, a wire rope, a hook, etc. which operate with a hydraulic cylinder. The hydraulic crane is provided with a relief valve (overload prevention valve) that automatically opens the pressure when excessive pressure is generated due to supply or discharge of hydraulic oil to a hydraulic cylinder (see, for example, Patent Document 1). For example, in the relief valve described in Patent Document 1, a hollow threaded portion, a cylindrical body fitted with a threaded portion and having a guide hole, a seat member fitted to the tip of the cylindrical body, and a guide portion inserted into the guide hole of the cylindrical body And a poppet member having a poppet portion pressed against the sheet member.

Japanese Utility Model Registration No. 2535322 Gazette

However, when the cylinder body and the seat member provided by the valve are separate, there is a possibility that hydraulic oil may leak from the gap between the cylinder body and the seat member. Therefore, there is room for improvement in order to suppress leakage of hydraulic oil from the gap between the cylindrical body and the sheet member.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a valve and a construction machine capable of suppressing leakage of fluid from a housing.

As a means of solving the above problems, an aspect of the present invention has the following configuration.

(1) The valve according to the aspect of the present invention has an outer circumferential surface and is provided at one end in the axial direction, and has an outer circumferential surface and has a central axis along the axial direction. A valve body having a tapering end portion having a smaller diameter, a fluid flow path, and a housing having an accommodation space for accommodating the valve body, the housing block the flow path by contacting the tapering portion. And, by contacting the outer circumferential surface of the body portion to guide the body portion along the axial direction.

According to this configuration, since the same member (housing) has the function of blocking the flow path and the guiding function of the body portion, a gap through which fluid leaks is not formed in the housing as in the case where the cylindrical body and the seat member are separate. Therefore, according to this configuration, leakage of fluid from the housing can be suppressed.

The valve according to the configuration is easier to arrange the housing coaxially with the valve body compared to the case where the cylinder body and the seat member are separate parts. Therefore, the valve according to the configuration can reduce the frictional resistance of the valve body with respect to the housing, thereby reducing the hysteresis of the override characteristic. That is, according to this configuration, even if the flow rate of the fluid increases, the set pressure (for example, the pressure when the valve body opens the flow path) can be kept constant.

Compared with the case where the cylinder body and the seat member are separate parts, the valve according to the configuration can reduce the number of parts and reduce the cost.

According to this configuration, since the valve body has a tapering portion whose diameter decreases from one end in the axial direction toward one side in the axial direction, the tapering portion is positioned to protrude outward from the outer diameter of the body portion (valve Compared with the case where the sieve has a mushroom shape), complicated processing becomes unnecessary. That is, the valve according to the configuration is easy to simply integrate the body portion and the tapered portion, and is excellent in workability.

(2) In the valve according to the above (1), the valve body is provided at one end of the body portion in the axial direction, and the first pressure receiving surface receiving the pressure of the fluid, and the other end of the body portion in the axial direction It may have a second pressure-receiving surface that is provided and has an external shape smaller than that of the first pressure-receiving surface as viewed from the axial direction.

(3) In the valve according to the above (2), the valve body may include a valve body having the first pressure receiving surface and a piston having the second pressure receiving surface.

(4) In the valve according to (3), the piston may have a curved surface facing one end of the valve body in the axial direction.

(5) In the valve according to (3) above, the valve body has a concave portion on a side opposite to the first pressure receiving surface in the axial direction, and the piston faces the concave portion, and the axis of the valve body You may have a convex curved surface on one side of the direction.

(6) A valve according to an aspect of the present invention is a valve comprising a valve body, a valve body including a piston in contact with the valve body, and a housing having an accommodation space for accommodating the valve body, the valve body , A typical first body portion having an outer circumferential surface and a central axis along the axial direction, and the first body portion is provided at one end in the axial direction, and the end of which the diameter decreases toward one side of the axial direction is thin. A load portion and a first pressure receiving surface provided at one end of the first body portion in the axial direction to receive fluid pressure, and the piston has the same central axis as that of the first body portion, and the first body portion in the axial direction. 1 It has a first end facing the body part, a second end opposite to the first end, and is provided in a normal second body part smaller than the first body part, and the second end of the second body part. A second pressure receiving surface having an external shape smaller than that of the first pressure receiving surface as viewed from the axial direction, and a curved surface provided at the first end of the second body portion, the housing has a fluid flow path, and the end is The flow path is blocked by contacting the tapered portion, and the first body portion is guided along the axis by contacting the outer circumferential surface of the first body portion.

According to this configuration, since the same member (housing) has the function of blocking the flow path and the guiding function of the first body portion, a gap through which fluid leaks is not formed in the housing as in the case where the cylindrical body and the seat member are separate. Therefore, according to this configuration, leakage of fluid from the housing can be suppressed.

The valve according to the configuration is easier to arrange the housing coaxially with the valve body compared to the case where the cylinder body and the seat member are separate parts. Therefore, the valve according to the configuration can reduce the frictional resistance of the valve body with respect to the housing and reduce the hysteresis of the override characteristic. That is, according to this configuration, even if the flow rate of the fluid increases, the set pressure (for example, the pressure when the valve body opens the flow path) can be kept constant.

Compared with the case where the cylinder body and the seat member are separate parts, the valve according to the configuration can reduce the number of parts and reduce the cost.

According to this configuration, since the valve body has a tapering portion whose diameter decreases from one end in the axial direction toward one side in the axial direction, the tapering portion protrudes outward from the outer diameter of the first body portion. Compared with (when the valve body has a mushroom shape), complicated processing becomes unnecessary. That is, it is easy to simply integrate the first body portion and the tapered portion, and the workability is excellent.

According to this configuration, when the pressure of the fluid acts on the second pressure receiving surface, the force acts in the direction in which the valve body closes the flow path (hereinafter, also referred to as "valve closing direction"). Therefore, when a spring for generating a force in the valve closing direction is provided in the valve according to the configuration, the spring can be made small.

In the valve according to the configuration, the friction of the valve body against the guide member (a member that guides the valve body along the axis) compared to the case where the first pressure receiving surface and the second pressure receiving surface are provided on the same member (valve body). Resistance can be made small. Therefore, the valve according to the configuration can reduce the hysteresis of the override characteristic. That is, according to this configuration, even if the flow rate of the fluid increases, the set pressure (for example, the pressure when the valve body opens the flow path) can be kept constant.

Compared with the case where the piston has a sharp edge on the outer periphery of the end edge in contact with the valve body, the valve according to the configuration affects the movement along the axis of the piston even if it is slightly inclined with respect to the axis when the piston moves along the axis line. You can restrain yourself from causing you.

(7) A valve according to an aspect of the present invention is a valve comprising a valve body, a valve body including a piston in contact with the valve body, and a housing having an accommodation space for accommodating the valve body, the valve body , A typical first body portion having an outer circumferential surface and a central axis along the axial direction, and the first body portion is provided at one end in the axial direction, and the end of which the diameter decreases toward one side of the axial direction is thin. A load portion, a first pressure receiving surface provided at one end of the first body portion in the axial direction to receive fluid pressure, and a concave portion provided on a side opposite to the first pressure receiving surface in the axial direction, wherein the piston comprises: It has the same central axis as the first body part, a first end facing the first body part in the axial direction, and a second end opposite to the first end, and is smaller than the first body part. 2 A body portion, a second pressure receiving surface provided at the second end of the second body portion and having an external shape smaller than that of the first pressure receiving surface when viewed from the axial direction, and the first receiving surface of the second body portion facing the concave portion. The first body has a convex curved surface provided at an end, the housing has a fluid flow path, blocks the flow path by contacting the tapered end portion, and contacts the outer circumferential surface of the first body part along the axis. Guide wealth.

According to this configuration, since the same member (housing) has the function of blocking the flow path and the guiding function of the first body portion, a gap through which fluid leaks is not formed in the housing as in the case where the cylindrical body and the seat member are separate. Therefore, according to this configuration, leakage of fluid from the housing can be suppressed.

According to this configuration, it is easier to arrange the housing coaxially with the valve body compared to the case where the cylinder body and the seat member are separate parts. Therefore, the frictional resistance of the valve body with respect to the housing can be reduced, and the hysteresis of the override characteristic can be reduced. That is, the valve according to the configuration can maintain a constant set pressure (for example, the pressure when the valve body opens the flow path) even when the flow rate of the fluid increases.

According to this configuration, compared with the case where the cylindrical body and the sheet member are separate parts, the number of parts can be reduced and cost reduction can be achieved.

According to this configuration, since the valve body has an end taper portion whose diameter decreases from one end in the axial direction toward one side in the axial direction, when the end taper portion is positioned to protrude outward than the outer periphery of the first body portion (the valve body is Compared with the case of having a mushroom shape), complicated processing becomes unnecessary. That is, it is easy to simply integrate the first body portion and the tapering portion, and the workability is excellent.

According to this configuration, when the pressure of the fluid acts on the second pressure receiving surface, the force acts in the direction in which the valve body closes the flow path (hereinafter, also referred to as "valve closing direction"). Therefore, when a spring for generating a force in the valve closing direction is provided, the spring can be made small.

According to this configuration, compared to the case where the first pressure receiving surface and the second pressure receiving surface are provided on the same member (valve body), the frictional resistance of the valve body with respect to the guide member (a member that guides the valve body along the axis) is increased. You can make it small. Therefore, the hysteresis of the override characteristic can be reduced. That is, the valve according to the configuration can maintain a constant set pressure (for example, the pressure when the valve body opens the flow path) even when the flow rate of the fluid increases.

Compared with the case where the piston has a sharp edge on the outer periphery of the end edge in contact with the valve body, the valve according to the configuration affects the movement along the axis of the piston even if it is slightly inclined with respect to the axis when the piston moves along the axis line. You can restrain yourself from causing you.

In this configuration, even if the piston is slightly inclined with respect to the axis when the piston moves along the axis line, the tilting of the piston is absorbed by the concave portion and the convex curved surface rubbing against each other. Therefore, it is possible to suppress the influence of the movement along the axis of the piston.

(8) A construction machine according to an aspect of the present invention is provided with the valve according to any one of (1) to (7) above.

According to the present invention, it is possible to provide a valve and a construction machine capable of suppressing leakage of fluid from a housing.

1 is a schematic diagram of a construction machine according to a first embodiment.
2 is a cross-sectional view of an example of an installation state of a valve according to the first embodiment.
3 is a cross-sectional view of the valve of the first embodiment.
4 is an enlarged view of a main part of FIG. 3.
5 is an explanatory diagram of an example of the operation of the valve of the first embodiment.
6 is a cross-sectional view of a valve according to a second embodiment.
7 is a cross-sectional view of a valve according to a third embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, a hydraulic crane provided with a valve having a function of a relief valve (overload prevention valve) as a construction machine will be described as an example. In addition, in the drawings used for the following description, the scale of each member is appropriately changed in order to make each member a recognizable size.

[First embodiment]

[Construction machinery]

1 is a schematic diagram of a construction machine 1 according to a first embodiment.

For example, the construction machine 1 is a rough terrain crane (hydraulic crane). The construction machine 1 is provided with a turning body 2 and a traveling body 3. The turning body 2 is provided on the traveling body 3 so that it can turn. The revolving body 2 is provided with a hydraulic pump (fluid supply source) (not shown) for supplying hydraulic oil (fluid).

The revolving body 2 includes a cab 5 in which an operator can ride, a boom 6 connected to the upper part of the traveling body 3 so that one end can swing, and a side opposite to the traveling body 3 of the boom 6. A jib 7 with one end connected to the other end (tip) so that it can swing, and a hook installed through a wire rope 8 at the other end (tip) of the jib 7 opposite to the boom 6 (not shown) It is equipped with. For example, a hydraulic pump (not shown) is arranged in the cap 5. The cap 5, the boom 6, the jib 7 and the hook are driven by the hydraulic oil supplied from the hydraulic pump.

[valve]

2 is a cross-sectional view of an example of the installation state of the valve 20 according to the first embodiment. 3 is a cross-sectional view of the valve 20 according to the first embodiment.

As shown in FIG. 2, the valve 20 includes a valve body 21, a housing 22, a case 23, a spring 24 (elastic member), and an adjuster 25. For example, the valve 20 is connected to the valve body 10 having a plurality of passages 11 to 13.

[Valve body]

As shown in FIG. 3, the valve body 21 includes a valve body 30 and a piston 40 in contact with the valve body 30.

The valve body 30 has a normal first body portion 31 along the axis C1, and one end (first body portion 31) of the first body portion 31 in the axial direction (direction along the axis C). ), and a tapering end portion 32 that decreases in diameter toward one side in the axial direction while being provided at the first end) of the first body portion 31, and a first pressure receiving surface 33 provided at one end of the first body portion 31 in the axial direction. , And a protrusion 34 protruding from the first pressure receiving surface 33. The first body portion 31 has an outer circumferential surface and has a central axis along the axial direction.

The first body portion 31 has a cylindrical shape with an axis line C1 as a central axis. The first body portion 31 has a first communication hole 35 along the axis C1 and an orifice 36 smaller than the first communication hole 35. The first communication hole 35 and the orifice 36 communicate with each other. The first communication hole 35 is opened in the center of the other end surface (the other end, the second end of the first body 31) opposite to the first pressure receiving surface 33 of the first body part 31 have. The orifice 36 is open at the center of the protrusion 34 of the first body 31.

The tapered end portion 32 has an outermost end on the outer periphery of the first body portion 31, and gradually toward the protrusion 34 so as to have an innermost end radially inner than the outer periphery of the first body portion 31. It is inclined. As viewed from the axial direction, the tapering portion 32 has an annular shape with the outer circumference of the first body portion 31 as the outermost diameter and the circumference on the first pressure receiving surface 33 as the innermost diameter.

The first pressure receiving surface 33 is a surface receiving pressure of hydraulic oil. In the drawings, reference numeral 11 denotes a primary side passage provided in the valve body 10 (see FIG. 2). The first pressure receiving surface 33 receives primary pressure by hydraulic oil flowing through the primary side passage 11 in the direction of arrow K1 (see Fig. 5).

The protrusion 34 protrudes from the central portion of the first pressure receiving surface 33 toward one side in the axial direction (inside of the primary side passage 11 ). The protrusion 34 is coaxial with the first body portion 31 and has a cylindrical shape of a smaller diameter than the first body portion 31. For example, the protrusion 34 is integrally formed with the same member as the first body portion 31.

The piston 40 includes a second body part 41 provided separately from the first body part 31 and the other end of the second body part 41 in the axial direction (the first hydraulic pressure of the second body part 41 ). A second pressure receiving surface 42 (a second end opposite to the first end) provided on the side opposite to the side 33 and a curved angle 43 provided at the outer periphery of one end in the axial direction of the second body part 41 ) (Refer to FIG. 4), and a receiving concave portion 44 provided on one end surface of the second body portion 41 in the axial direction (the first end facing the first body portion 31), and a second body portion A flange 45 provided on the outer periphery of the other end in the axial direction of 41 is provided.

The second body part 41 has a cylindrical shape with the axis line C1 as a central axis. The second body portion 41 has a cylindrical shape smaller in diameter than the first body portion 31. The second body portion 41 is disposed coaxially with the first body portion 31. The 2nd body part 41 has a 2nd communication hole 46 along the axis line C1. The second communication hole 46 is the central portion of the receiving concave portion 44 in the second body portion 41 and the other end surface of the second body portion 41 (the second surface of the second body portion 41 ). ) Are opened in each of the central parts.

The second pressure receiving surface 42 has an external shape smaller than that of the first pressure receiving surface 33 when viewed from the axial direction. The second pressure receiving surface 42 has an area smaller than that of the first pressure receiving surface 33. In the drawing, the area of the first pressure receiving surface 33 is indicated by A1, and the area of the second pressure receiving surface 42 is indicated by A2 (A2<A1). The second pressure receiving surface 42 is a surface receiving pressure of hydraulic oil and a spring force of the spring 24. The second pressure receiving surface 42 receives pressure by hydraulic oil flowing through the second communication hole 46 in the direction of arrow K2 (see Fig. 5).

4 is an enlarged view of a main part of FIG. 3.

As shown in FIG. 4, the curved angle 43 is a curved angle provided on the outer periphery of the end edge in contact with the valve body 30 of the second body portion 41. The bend angle 43 is convex and curved outward so as to have an outermost end on the outer circumference of the second body part 41 and an innermost end radially inner than the outer circumference of the second body part 41. . As viewed from the axial direction, the curved angle 43 has an annular shape in which the outer circumference of the second body portion 41 is the outermost diameter, and the periphery of the end surface of the second body portion 41 is the innermost diameter.

As shown in FIG. 3, the accommodation concave part 44 is a concave part in the center part of the one end surface of the 2nd body part 41. As shown in FIG. The annular sealing member 28 is accommodated in the accommodation concave portion 44. The sealing member 28 is disposed between the other end surface of the first body portion 31 and the one end surface of the second body portion 41. One end surface of the second body part 41 is in contact with the other end surface of the first body part 31 in a compressed state of the sealing member 28.

The flange 45 protrudes outward in the radial direction from the outer periphery of the other end of the second body 41 (the outer periphery of the second surface of the second body 41). When viewed from the axial direction, the flange 45 has an annular shape larger than the outer diameter of the second body portion 41. The flange 45 is integrally formed with the same member as the second body part 41.

[housing]

The housing 22 has a cylindrical shape with the axis line C1 as a central axis. The housing 22 covers the valve body 30 from the outside in the radial direction. The housing 22 has an accommodation space 50 accommodating the valve body 30. The housing 22 has flow paths 51 and 52 for hydraulic oil. The housing 22 blocks the flow paths 51 and 52 by contacting the tapering portion 32. The housing 22 guides the first body portion 31 along the axis C1 by contacting the outer peripheral surface of the first body portion 31.

In the drawing, reference numeral 53 denotes a portion that contacts the tapered portion 32 when the housing 22 blocks the flow paths 51 and 52 (hereinafter, also referred to as ``retaining support wall''), and reference numeral 54 denotes the housing 22. A portion for guiding the first body portion 31 (hereinafter, also referred to as a “guide wall”) and reference numeral 55 denote an O-ring provided in a groove on the outer periphery of the housing 22, respectively.

The flow paths 51 and 52 can communicate with the inside of the housing 22 (receiving space 50) and the outside of the housing 22. The flow paths 51 and 52 open both side portions of the housing 22 in a direction perpendicular to the axis C1 (hereinafter, also referred to as "diameter direction"). A plurality of flow paths 51 and 52 are provided. The plurality of flow paths 51 and 52 are a first flow path 51 that opens one side of the housing 22 and a second flow path 52 that opens the other side of the housing 22. In the drawings, reference numerals 12 and 13 denote a secondary side passage provided in the valve body 10 (see FIG. 2). Each of the flow paths 51 and 52 communicates the primary side passage 11 and the secondary side passages 12 and 13 when the pressure of the primary side passage 11 exceeds a threshold (set pressure) (see FIG. 5 ). ).

The holding wall 53 is a part of the housing 22 near the primary side passage 11. The inner diameter of the holding wall 53 is smaller than the outer diameter of the first body portion 31. The holding wall 53 has a sheet edge 53a that contacts the tapering portion 32. The sheet frame 53a is a corner positioned at an end edge on the inner periphery of the holding wall 53 on the side opposite to the primary side passage 11. The sheet frame 53a faces the central portion in the oblique direction of the tapering portion 32.

The guide wall 54 is a part of the housing 22 on the opposite side to the primary side passage 11. The inner diameter of the guide wall 54 has substantially the same size as the outer diameter of the first body portion 31. The length of the guide wall 54 in the axial direction is longer than that of the holding wall 53. The guide wall 54 has a length that allows a toothed body portion of the valve body 30 in the axial direction. The guide wall 54 and the holding wall 53 are integrally formed by the same member.

[case]

The case 23 has a normal shape with the axis line C1 as a central axis. The case 23 has a screw 60 attached to the valve body 10 (see FIG. 2) and a case body 61 accommodating a spring 24. The screw 60 and the case body 61 are integrally formed by the same member. In the drawing, reference numeral 62 denotes an O-ring provided in a groove on the outer periphery of the screw 60.

The screw 60 has a normal protruding from one end surface of the case body 61 in the axial direction to one side in the axial direction. The screw 60 covers the guide wall 54 of the housing 22 from the outside in the radial direction. The guide wall 54 is provided on the inner periphery of the screw 60. In the drawing, reference numeral 63 denotes a discharge hole for discharging the hydraulic oil flowing between the guide wall 54 and the screw 60 out of the case 23.

When viewed from the axial direction, the case body 61 has an outer diameter larger than that of the screw 60. The case body 61 has a spring accommodation chamber 65 for accommodating the spring 24 and a second guide wall 66 for guiding the piston 40 along the axis C1.

The spring accommodating chamber 65 is in communication with the primary side passage 11 through the orifice 36, the first communication hole 35, and the second communication hole 46. When viewed from the axial direction, the spring accommodation chamber 65 is larger than the outer diameter of the piston 40 (the outer diameter of the flange 45).

The second guide wall 66 is a portion of the case body 61 near the screw 60. The inner diameter of the second guide wall 66 is substantially the same as the outer diameter of the second body portion 41. The length of the second guide wall 66 in the axial direction is shorter than that of the second body part 41. The second guide wall 66 has a length that allows a two body portion in the axial direction of the second body portion 41.

[spring]

The spring 24 elastically supports the valve body 21. The spring 24 is accommodated in the spring accommodating chamber 65. The spring 24 is disposed coaxially with the valve body 21. The spring 24 is elastically deformable in the axial direction. The spring 24 is disposed between the second pressure receiving surface 42 of the piston 40 and the inner bottom surface of the adjuster 25. The spring 24 makes the valve body 21 1 so as to block the primary side passage 11 and the passage (secondary side passages 12 and 13) by contacting the tapering portion 32 and the holding wall 53. It is always pressed toward the vehicle side passage 11. Hereinafter, the force by which the spring 24 presses the valve body 21 toward the primary side passage 11 is also referred to as a "spring force".

[Adjuster]

The adjuster 25 is provided on the other end surface of the case body 61 in the axial direction (a surface opposite to the surface of the case body 61 from which the valve body 30 protrudes). The adjuster 25 is a member for adjusting the spring force (set pressure of the relief valve) of the spring 24. The adjuster 25 has a tubular shape with a bottom coaxial with the case 23. The adjuster 25 is movable in the axial direction while being engaged with the screw of the inner circumference of the case body 61 by rotating the adjuster 25 itself around the axial line C1. In the drawing, reference numeral 70 denotes a screw provided on the outer periphery of the adjuster 25, and reference numeral 71 denotes a nut for fixing the adjuster 25 to the other side of the case body 61, respectively.

[Valve operation]

5 is an explanatory diagram of an example of the operation of the valve 20 according to the first embodiment. 5 shows a time when hydraulic oil is supplied from the primary side passage 11. In FIG. 5, the state in which the valve body 21 is connected to the primary side passage 11 and the secondary side passages 12, 13 is shown by a solid line, and the valve body 21 is the primary side passage 11 and 2 The state in which the vehicle side passages 12 and 13 are blocked is indicated by a double-dashed line.

As shown in Fig. 5, when hydraulic oil is supplied from the primary side passage 11, in the axial direction, the pressure direction received by the first pressure receiving surface 33 of the valve body 21 (valve body 30) ( Valve opening direction) (see arrow K1 in Fig. 5). At this time, a part of the hydraulic oil is passed through the orifice 36, the first communication hole 35, and the second communication hole 46 to the second pressure receiving surface 42 of the valve body 21 (piston 40). It works (see arrow K2 in the drawing). When a part of the hydraulic oil acts on the second pressure receiving surface 42, the piston 40 is pressed at a predetermined pressure in a direction opposite to the pressure received by the first pressure receiving surface 33 (valve closing direction).

At this time, the valve body 21 (the tapering portion 32) is the sum of the force acting on the second pressure receiving surface 42 by a part of the hydraulic oil and the spring force of the spring 24 (hereinafter also referred to as ``resulting force''). Is pressed against the seat edge 53a (refer to the valve body 21 shown in the double-dotted line). In the axial direction, when the first pressure-receiving surface 33 of the valve body 21 is pressed stronger than the resultant force, the valve body 21 resists the spring 24 and the adjuster 25 side (valve opening direction) Is displaced. That is, when hydraulic oil is supplied from the primary side passage 11, when the pressure acting on the first pressure receiving surface 33 exceeds the set pressure, the valve body 21 moves against the spring 24 and moves 1 The vehicle side passage 11 and the secondary side passages 12 and 13 are communicated (refer to the valve body 21 shown in solid line). Thereby, hydraulic oil flows from the primary side passage 11 toward the secondary side passages 12 and 13 (refer to arrow W1 in the drawing).

As described above, the valve 20 according to the present embodiment has one end in the axial direction of the normal first body portion 31 and the first body portion 31 along the axis line C1 in the axial direction. A valve body 30 having a first pressure receiving surface 33 provided on one end surface in the axial direction of the end tapering part 32 and the first body part 31 to receive the pressure of the hydraulic oil, and the axis line ( Along C1), it is provided at the other end (second end) in the axial direction of the normal second body part 41, which is smaller than the first body part 31, and the first pressure receiving surface as viewed from the axial direction. A valve body (21) having a second pressure receiving surface (42) having a smaller outer shape than (33) and a piston (40) having a curved angle (43) provided at one end in the axial direction of the second body part (41), It has the flow paths 51 and 52 of hydraulic oil, blocks the flow paths 51 and 52 by contacting the tapered end 32, and contacts the outer circumferential surface of the first body 31 to form a first along the axis C1. It has a housing (22) for guiding the body portion (31).

According to this configuration, since the same member (housing 22) has the blocking function of the flow paths 51 and 52 and the guiding function of the first body part 31, the hydraulic oil is The leaking gap is not formed in the housing 22. Accordingly, leakage of hydraulic oil from the housing 22 can be suppressed.

In addition, compared with the case where the cylinder body and the seat member are separate parts, the housing 22 is easier to arrange coaxially with the valve body 21. Therefore, the frictional resistance of the valve body 21 with respect to the housing 22 can be made small, and the hysteresis of the override characteristic can be reduced. That is, the valve 20 according to the present embodiment can maintain a constant set pressure (for example, the pressure when the valve body 21 opens the flow path) even if the flow rate of the hydraulic oil increases.

Moreover, compared with the case where the cylindrical body and the sheet member are separate parts, the number of parts can be reduced, and cost reduction can be achieved.

Further, since the valve body 21 has an end taper portion 32 whose diameter decreases from one end in the axial direction toward one side in the axial direction, the end taper portion 32 is larger than the outer diameter of the first body portion 31. Compared with the case where it protrudes outward (the case where the valve body 21 has a mushroom shape), complicated processing becomes unnecessary. That is, it is easy to simply integrate the first body portion 31 and the tapering portion 32, and the workability is excellent.

In addition, the valve body 21 is provided at one end in the axial direction of the first body portion 31 and receives the pressure of hydraulic oil, and the other end of the second body portion 41 in the axial direction ( The following effects are exhibited by having the second pressure receiving surface 42 provided in the second stage) and having a smaller external shape than the first pressure receiving surface 33.

When the pressure of the hydraulic oil acts on the second pressure receiving surface 42, a force acts in the valve closing direction. Therefore, the spring 24 for generating a force in the valve closing direction can be made small.

Further, the valve body 21 exhibits the following effects by providing the valve body 30 having the first pressure receiving surface 33 and the piston 40 having the second pressure receiving surface 42.

Compared to the case where the first pressure-receiving surface 33 and the second pressure-receiving surface 42 are provided on the same member (valve body 21), a guide member (to guide the valve body 21 along the axis C1) The frictional resistance of the valve body 21 with respect to the member) can be made small. Therefore, the valve 20 according to the present embodiment can reduce the hysteresis of the override characteristic.

Further, the piston 40 exhibits the following effects by having a bend angle 43 provided on the outer periphery of the end edge in contact with the valve body 30.

Compared with the case where the piston 40 has a sharp edge on the outer periphery of the end edge in contact with the valve body 30, even if the piston 40 is slightly inclined with respect to the axis line C1 when moving along the axis line C1, Influencing the movement along the axis C1 of the piston 40 can be suppressed.

The construction machine 1 according to the present embodiment is provided with the valve 20 described above.

According to this configuration, it is possible to provide the construction machine 1 capable of suppressing leakage of hydraulic oil.

In addition, the technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be added without departing from the spirit of the present invention.

For example, in the above-described embodiment, the construction machine 1 was described as an example of a hydraulic crane, but it is not limited to this. For example, you may apply this invention to construction machines other than hydraulic cranes, such as a hydraulic excavator.

In the above-described embodiment, an example in which the valve body 30 includes the protrusion 34 protruding from the first pressure receiving surface 33 has been described, but the present invention is not limited thereto. For example, the valve body 30 does not need to have the protrusion 34. That is, the first pressure receiving surface 33 may be a flat surface.

[Second Embodiment]

6 is a cross-sectional view of a valve 220 according to a second embodiment.

In the first embodiment described above, for example, the valve body 21 includes a valve body 30 having a first pressure receiving surface 33 and a piston 40 having a second pressure receiving surface 42. Although described, it is not limited to this. For example, as shown in FIG. 6, the valve body 221 is integrally formed with the first valve cylinder 230 having a first pressure receiving surface 33 and the first valve cylinder 230, You may be provided with the 2nd valve cylinder 240 which has the 2nd pressure-receiving surface 42. That is, the valve body 221 may be formed by a single member. In other words, the first valve cylinder 230 and the second valve cylinder 240 may be integrally formed with the same member. In Fig. 6, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

The valve 220 is a single valve body having a normal single body portion 231 along the axis C1 and a tapering portion 32 that decreases in diameter from one end in the axial direction toward one side in the axial direction ( 221). The valve body 221 has an orifice 36 and a communication hole 235 communicating with the orifice 36. The 2nd valve cylinder 240 has a columnar shape along the axis line C1. The 2nd valve cylinder 240 does not have a flange 45.

In the present embodiment, the valve body 221 is formed integrally with the first valve cylinder 230 having the first pressure receiving surface 33 and the first valve cylinder 230 to form the second pressure receiving surface 42. It has a second valve cylinder 240 having.

According to this configuration, since the valve body 221 is disposed across the guide wall 54 and the second guide wall 66, the valve body 221 is in a state in which the housing 22 is assembled to the valve body 221. And it becomes difficult to secure the coaxiality of the guide wall 54. Therefore, compared to the case where the first pressure-receiving surface 33 and the second pressure-receiving surface 42 are provided in separate members, the guide member (a member that guides the valve body 221 along the axis C1) The frictional resistance of the valve body 221 is increased. Therefore, the valve 220 of the second embodiment can make the override characteristic worse and increase its hysteresis. By the way, in a specific operation (for example, a undulation and prone operation in a crane), the relief valve which deliberately deteriorated the override characteristic may be adopted. Therefore, the configuration of the present embodiment is suitable for a relief valve used for such a specific operation.

[Third Embodiment]

7 is a cross-sectional view of a valve 320 according to a third embodiment.

In the above-described first embodiment, for example, the valve 20 includes a sealing member 28 disposed between the other end surface of the first body portion 31 and the one end surface of the second body portion 41. Although described, it is not limited to this. For example, as shown in FIG. 7, the valve 320 does not have to have the sealing member 28. In Fig. 7, the same reference numerals denote the same components as those of the first embodiment, and detailed descriptions thereof are omitted.

The valve body 330 has a concave portion 338 provided in a portion on the side opposite to the first pressure receiving surface 33 in the axial direction. The concave portion 338 has a hemispherical spherical bottom surface 338a. A first communication hole 335 is opened in the central portion of the spherical bottom surface 338a.

The piston 340 has a convex surface 348 that is convex on one side of the valve body 330 in the axial direction opposite to the concave portion 338. The convex surface 348 has a hemispherical spherical end surface 348a (curved surface) opposed to the spherical bottom surface 338a of the concave portion 338. A second communication hole 346 is opened in the central portion of the spherical end surface 348a. A gap 349 is formed between the outer circumferential surface of the convex surface 348 and the inner circumferential surface of the concave portion 338. The gap 349 has a size that allows tilting of the piston 340 with respect to the axis C1. The piston 340 does not have a flange 45.

In this embodiment, the valve body 330 has a concave portion 338 including a spherical bottom surface 338a on a side opposite to the first pressure receiving surface 33 in the axial direction, and the piston 340 is a concave portion It has a convex surface 348 including a convex spherical end surface 348a on one side of the valve body 330 in the axial direction opposite to 338.

According to this configuration, even if the piston 340 is slightly inclined with respect to the axis C1 when moving along the axis C1, the spherical bottom surface 338a of the concave portion 338 and the spherical end surface of the convex surface 348 The tilting of the piston 340 is absorbed as the 348a rub against each other. Therefore, it is possible to suppress an influence on the movement of the piston 340 along the axis C1.

In addition, it is possible to replace the constituent elements in the above-described embodiments with known constituent elements without departing from the spirit of the present invention. Moreover, you may combine each of the above-described modified examples.

1: hydraulic crane (construction machinery)
20: valve
21: valve body
22: housing
30: valve body
31: first body part (body part)
32: end taper
33: first water pressure surface
40: piston
41: second body portion (body portion)
42: second hydraulic surface
43: angle of curvature
51: 1st Euro (Euro)
52: 2nd Euro (Euro)
53: holding wall
54: guide wall
220: valve
221: single valve body (valve body)
231: single body part (body part)
320: valve
330: valve body
338: recess
338a: concept base
340: piston
348: convex surface
348a: spherical end face
C1: axis

Claims (8)

A valve body having an outer circumferential surface and having a central axis along the axial direction, and a tapering end portion provided at one end of the body portion in the axial direction and decreasing in diameter toward one side of the axial direction;
A housing having a fluid flow path and an accommodation space for accommodating the valve body
And,
The housing,
A valve that blocks the flow path by contacting the tapered end portion, and guides the body portion along the axial direction by contacting the outer circumferential surface of the body portion. The method of claim 1, wherein the valve body,
A first pressure receiving surface provided at one end of the body portion in the axial direction and receiving the pressure of the fluid,
A valve having a second pressure receiving surface provided at the other end of the body portion in the axial direction and having an external shape smaller than that of the first pressure receiving surface when viewed from the axial direction. The method of claim 2, wherein the valve body,
A valve body having the first pressure receiving surface,
A valve comprising a piston having the second pressure receiving surface. The valve according to claim 3, wherein the piston has a curved surface facing the other end of the valve body in the axial direction. The valve body according to claim 3, wherein the valve body has a concave portion on a side opposite to the first pressure receiving surface in the axial direction,
The piston has a convex curved surface on one side of the valve body in the axial direction facing the concave portion. A valve body including a valve body and a piston in contact with the valve body,
It is a valve having a housing having an accommodation space for accommodating the valve body,
The valve body,
A general first body portion having an outer circumferential surface and having a central axis along the axial direction,
An end tapering portion provided at one end of the first body portion in the axial direction and decreasing in diameter toward one side of the axial direction;
It has a first pressure receiving surface provided at one end in the axial direction of the first body portion to receive pressure of a fluid,
The piston,
The first body has the same central axis as the first body, a first end facing the first body in the axial direction, and a second end opposite to the first end, and the second body has a diameter of the first body A second body part smaller than the diameter of the part,
A second pressure receiving surface provided at the second end of the second body portion and having an external shape smaller than that of the first pressure receiving surface as viewed from the axial direction;
It has a curved surface provided at the first end of the second body part,
The housing,
A valve having a fluid flow path, blocking the flow path by contacting the tapered end portion, and guiding the first body portion along the axis by contacting the outer circumferential surface of the first body portion. A valve body including a valve body and a piston in contact with the valve body,
It is a valve having a housing having an accommodation space for accommodating the valve body,
The valve body,
A general first body portion having an outer circumferential surface and having a central axis along the axial direction,
An end tapering portion provided at one end of the first body portion in the axial direction and decreasing in diameter toward one side of the axial direction;
A first pressure receiving surface provided at one end of the first body portion in the axial direction and receiving fluid pressure,
It has a concave portion provided on a side opposite to the first pressure receiving surface in the axial direction,
The piston,
It has the same central axis as the first body part, a first end facing the first body part in the axial direction, and a second end opposite to the first end, and is smaller than the first body part. A second body part,
A second pressure receiving surface provided at the second end of the second body portion and having an external shape smaller than that of the first pressure receiving surface as viewed from the axial direction;
It has a convex curved surface provided at the first end of the second body portion facing the concave portion,
The housing,
A valve having a fluid flow path, blocking the flow path by contacting the tapered end portion, and guiding the first body portion along the axis by contacting the outer circumferential surface of the first body portion. A construction machine comprising the valve according to any one of claims 1 to 7.

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