CN111473011A - Flow control valve and working machine - Google Patents

Flow control valve and working machine Download PDF

Info

Publication number
CN111473011A
CN111473011A CN202010073712.1A CN202010073712A CN111473011A CN 111473011 A CN111473011 A CN 111473011A CN 202010073712 A CN202010073712 A CN 202010073712A CN 111473011 A CN111473011 A CN 111473011A
Authority
CN
China
Prior art keywords
valve
valve member
housing
control valve
flow rate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010073712.1A
Other languages
Chinese (zh)
Inventor
岩崎仁
后藤敬介
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nabtesco Corp
Original Assignee
Nabtesco Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nabtesco Corp filed Critical Nabtesco Corp
Publication of CN111473011A publication Critical patent/CN111473011A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/021—Valves for interconnecting the fluid chambers of an actuator
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K11/00—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves
    • F16K11/02—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit
    • F16K11/04—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only lift valves
    • F16K11/044—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only lift valves with movable valve members positioned between valve seats
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/001—Servomotor systems with fluidic control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K27/00—Construction of housing; Use of materials therefor
    • F16K27/02—Construction of housing; Use of materials therefor of lift valves
    • F16K27/0263—Construction of housing; Use of materials therefor of lift valves multiple way valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Valve Housings (AREA)
  • Details Of Valves (AREA)

Abstract

The invention provides a flow control valve and a working machine. A response delay is prevented from being generated in the flow control valve. In addition, the number of replacement parts when changing the function of the flow control valve is reduced. A flow control valve (20) is provided with a housing (30) having two ports (30a, 30b) and an internal space (S) having a shape with stepped portions (33, 38) and connected to the two ports (30a, 30b), and a valve structure (40) having: a throttle section (62) provided in a flow path connecting the two ports (30a, 30 b); a contact section (53) having a surface (53a) that is not parallel to the direction of movement and that can block the other flow path by contacting the step sections (33, 38); and a pressing member (70) that presses the contact portion (53) so that the contact portion can contact the step portions (33, 38) of the housing (30), wherein the valve structure (40) is movably housed in the internal space (S) of the housing (30).

Description

Flow control valve and working machine
Technical Field
The present invention relates to a flow rate control valve that controls the flow rate of a fluid flowing therethrough, and a work machine equipped with the flow rate control valve.
Background
Conventionally, in various fluid circuits, a flow rate control valve for controlling a flow rate of a fluid flowing through the fluid circuit is used. For example, in a working machine such as a construction vehicle driven by hydraulic pressure, a flow rate control valve for controlling the flow rate of oil flowing through a hydraulic circuit is used in the hydraulic circuit for supplying hydraulic oil to each hydraulic actuator of the working machine and in the hydraulic circuit for supplying pilot pressure for operating a hydraulic device such as a directional valve.
Japanese JPH08-312801a discloses a non-impact valve, which includes: an input port; an output port; a main body portion; a spool inserted into a fluid chamber inside the main body so as to be movable in a longitudinal direction; a 1 st spring that urges the spool toward the input port side; and a 2 nd spring that urges the spool toward the output port side. In this non-impact valve, when the pilot valve is set to the neutral position in order to stop the driving of the hydraulic actuator, the output of the pressure oil from the pilot valve is stopped, and the pressure on the input port side of the non-impact valve is abruptly reduced. Accordingly, the pressure oil flows from the output port into the output port side spool inner chamber in the fluid chamber, and flows into the input port side spool inner chamber through the throttle communication hole. At this time, a differential pressure is generated before and after the throttle communication hole, and the spool moves toward the input port. Thus, the opening formed by the 1 st communication hole communicating the input port side spool inner chamber and the 1 st annular groove is narrowed, and the flow of the pressure oil passing therethrough is restricted. When the pressure oil further flows, the spool stops at a position where the differential pressure between before and after the orifice communication hole and the biasing force of the 2 nd spring are balanced, the opening of the 1 st communication hole is adjusted, and the flow rate of the pressure oil from the output port side to the input port side is constant. Thus, even if the output of the pressure oil from the pilot valve is abruptly stopped, the speed of the return operation of the spool in the control valve can be slowed. Therefore, the impulsive operation of the pilot valve can be buffered.
In the reversing valve disclosed in japanese JPS55-107101a, two holes opened in the outer wall of the housing are provided, and a throttle valve with a check valve is fixed to each of the holes. The throttle valve with the check valve controls oil quantity in an inlet throttling mode and an outlet throttling mode respectively. The two holes are formed in the same shape and the same size, and the two throttle valves with the check valves can be replaced according to the use and the use condition. Therefore, the throttle valve with a check valve disclosed in jp ps55-107101a has an advantage that it can satisfy a wide range of applications and use conditions by having compatibility.
In the non-surge valve disclosed in jp h08-312801a, when pressure oil is output from the pilot valve in order to drive the hydraulic actuator, the pressure oil that flows into the non-surge valve via the input port flows into the input port side spool internal chamber via the communication path, the 1 st annular groove, and the 1 st communication hole of the spool, and further flows to the output port side via the orifice communication hole. When oil passes through the orifice communication hole, a differential pressure is generated before and after the orifice communication hole, and when the differential pressure is larger than the biasing force of the 1 st spring, the spool moves toward the output port against the biasing force of the 1 st spring. Thus, the 1 st annular groove and the 2 nd annular groove communicate with each other through the outer peripheral groove of the spool, and the pressure oil flows into the output port side spool core chamber through the 2 nd communication hole. At this time, the non-impact valve 1 is interposed between the pilot valve and the control valve, and the action of the control valve causes a delay in response. This delay in response acts to mitigate the impulsive action of the control valve. On the other hand, if such a delay in response occurs at the start of driving of the hydraulic actuator, there are problems as follows: the operator feels that the hydraulic actuator is slowly operated, and a sense of incongruity is generated.
Further, the throttle valve with a check valve for the meter-in system disclosed in jp ps55-107101a is completely different from the throttle valve with a check valve for the meter-out system in terms of component parts, and when the throttle valve with a check valve is replaced, the entire throttle valve with a check valve needs to be replaced with another throttle valve with a check valve. Therefore, the number of replacement parts increases, which causes a problem of an increase in manufacturing cost of the throttle valve with the check valve, and in labor and time for replacement.
Disclosure of Invention
The present invention has been made in view of such a point, and an object thereof is to prevent a response delay from occurring in a flow rate control valve. Further, the present invention aims to reduce the number of parts to be replaced when the function of the flow control valve is changed.
The flow control valve of the present invention includes:
a housing having: two ports; and an internal space having a shape of a stepped portion, connected to the two ports; and
a valve structure body having: a throttle portion provided in a flow path connecting the two ports; a contact portion having a surface not parallel to the moving direction and capable of blocking the other flow path by contacting the stepped portion; and a pressing member that presses the contact portion so that the contact portion can contact the stepped portion of the housing, wherein the valve structure is movably housed in the internal space of the housing.
In the flow control valve of the present invention, it is also possible,
the contact portion is formed in a valve member, the throttle portion is formed in another valve member, and the pressing member presses the valve member and the another valve member so as to be separated from each other.
In the flow control valve of the present invention, it is also possible,
the opening area of the opening of the flow path changes when the other valve member moves so as to approach the valve member.
In the flow control valve of the present invention, it is also possible,
the housing can house the valve structure even if the valve structure is reversed in the moving direction.
The flow control valve of the present invention includes:
a housing having two ports and an internal space connecting the two ports internally; and
a valve structure body having: a contact portion contactable with one port of the housing in the internal space of the housing; and a throttle portion disposed between the one port and the other port,
a flow path through a throttle portion is formed between the two ports in a state where the contact portion of the valve structure is in contact with the housing,
in a state where the contact portion of the valve structure is separated from the housing, a flow path bypassing the throttle portion is formed.
The flow control valve of the present invention includes:
a housing having: two ports; and an internal space having a shape of a 1 st step part and a 2 nd step part, connected to the two ports;
a 1 st valve member movably housed in the internal space of the housing, the first valve member including: a 1 st contact part having a surface not parallel to a moving direction and capable of contacting the 1 st step part; a central passage connecting one side and the other side of the 1 st contact part in the moving direction, the one side of the central passage being closed and the other side of the central passage being open; and an opening portion formed in a radial direction from the central passage on the one side of the 1 st contact portion;
a 2 nd valve member movably housed in the internal space of the housing, the 2 nd valve member including: a 2 nd contact portion contactable with the 2 nd step portion of the housing; a shaft portion that is integrally formed with the 2 nd contact portion and is movable in the axial direction in the central passage of the 1 st valve member; a hollow portion of which the one side in the moving direction of the shaft portion is open and the other side is closed; and a throttle portion formed in a radial direction from the hollow portion; and
a pressing member that separates the 1 st valve member and the 2 nd valve member.
The work machine of the present invention includes the flow rate control valve.
ADVANTAGEOUS EFFECTS OF INVENTION
According to the present invention, it is possible to prevent a response delay from occurring in the flow rate control valve. Further, according to the present invention, the number of replacement parts when changing the function of the flow rate control valve can be reduced.
Drawings
Fig. 1 is a diagram for explaining an embodiment of the present invention, and is a hydraulic circuit diagram showing an example of a hydraulic circuit of a working machine incorporating a flow control valve.
Fig. 2 is a hydraulic circuit diagram showing an example of the flow control valve.
Fig. 3 is a longitudinal sectional view showing an example of the flow rate control valve.
Fig. 4 is a perspective view showing the shape of the 2 nd contact portion of the 2 nd valve member of the flow rate control valve.
Fig. 5 is a diagram for explaining the operation of the flow control valve.
Fig. 6 is a diagram for explaining the operation of the flow control valve.
Fig. 7 is a longitudinal sectional view showing the flow rate control valve by turning over the valve structure.
Description of the reference numerals
10. A hydraulic circuit; 11. a hydraulic pump; 12. a hydraulic actuator; 13. a spool valve; 16. a pilot pump; 17. a remote control valve; 19. a tank; 20. a flow control valve; 30. a housing; 30a, port 1; 30b, 2 nd port; 31. 1, a first shell; 33. a 1 st step portion; 35. a 2 nd housing; 40. a valve structure; 50. a 1 st valve member; 51. a passage; 52. an opening part; 53. the 1 st contact part; 54. a central passageway; 60. a 2 nd valve member; 61. a shaft portion; 62. a throttle section; 63. a hollow portion; 64. an end portion; 65. the 2 nd contact part; 66. a notch portion; 70. a pressing member; A. a central axis; e1, No. 1 fluid pressure element; e2, 2 nd fluid pressure element; c1, 1 st pressure chamber; c2, 2 nd pressure chamber; s, an inner space.
Detailed Description
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, the scale, the vertical and horizontal size ratio, and the like are appropriately changed and enlarged with respect to the actual scale, the vertical and horizontal size ratio, and the like, for the sake of easy illustration and understanding.
In addition, terms used in the present specification, such as "parallel", "orthogonal" and "the same", terms for determining the degree of the geometrical and the shape thereof, and values of length and angle are not limited to strict meanings, and are interpreted to include ranges of degrees to which the same functions can be expected.
Fig. 1 to 7 are diagrams for explaining an embodiment of the present invention. In the present embodiment, an example in which the flow rate control valve 20 is used as a so-called non-impact valve in the hydraulic circuit 10 is described, but the use of the flow rate control valve 20 is not limited thereto, and the flow rate control valve can be used by being disposed at a position where the flow rate of the fluid is to be controlled in various fluid circuits. Fig. 1 is a hydraulic circuit diagram showing an example of a hydraulic circuit 10 of a working machine in which a flow rate control valve 20 is incorporated.
The hydraulic circuit 10 shown in fig. 1 includes: a spool 13 that controls the flow rate of the hydraulic oil discharged from the hydraulic pump 11 and directed to the hydraulic actuator 12; a remote control valve 17 that selects a flow path of pilot oil generated by the pilot pump 16; and a flow control valve (non-impact valve) 20 that controls the flow rate of the pilot oil flowing between the spool 13 and the remote control valve 17.
The spool valve 13 has a spool 14. The position of the spool 14 along the axial direction (the longitudinal direction, the left-right direction in fig. 1) is changed by the action of the pilot pressure, which is the pressure of the pilot oil generated by the pilot pump 16, and thereby the flow rate of the hydraulic oil discharged from the hydraulic pump 11 and heading toward the hydraulic actuator 12 is continuously changed. The pilot pump 16 is a hydraulic pump that discharges pilot oil having a constant pilot pressure at all times, and a gear pump is used as an example. In the illustrated example, when the pilot pressure does not act on any one of one end (right end in fig. 1) and the other end (left end in fig. 1) of the spool 14 in the axial direction, the spool 14 is positioned at the position closest to the one end side by the pressing force of the spring 15. When the pilot pressure acts on one end of the spool 14 via the flow path 101 and the spool 14 moves toward the other end side against the pressing force of the spring 15, the flow rate of the hydraulic oil discharged from the hydraulic pump 11 and heading toward the hydraulic actuator 12 increases. Further, when the pilot pressure acts on the other end of the spool 14 via the flow path 102 and the spool 14 moves toward one end side, the flow rate of the hydraulic oil decreases.
The remote control valve 17 has an operation lever 18 operated by an operator, and selects and connects a flow path of pilot oil generated by the pilot pump 16 from the flow path 101, the flow path 102, and the tank 19 in accordance with the operation of the operation lever 18. When the control lever 18 is in the neutral position, the remote control valve 17 communicates the pilot pump 16 and the tank 19. When the operation lever 18 is operated to the 1 st operation position, the remote control valve 17 causes the pilot pump 16 to communicate with the flow passage 101, and causes the flow passage 102 to communicate with the tank 19. When the operation lever 18 is operated to the 2 nd operation position different from the 1 st operation position, the remote control valve 17 causes the pilot pump 16 to communicate with the flow passage 102, and causes the flow passage 101 to communicate with the tank 19.
In the illustrated hydraulic circuit 10, when the operator does not operate the operation lever 18, the operation lever 18 of the remote control valve 17 is positioned at the neutral position, and the pilot oil generated by the pilot pump 16 is discharged to the tank 19 through the remote control valve 17. Thus, the pilot pressure does not act on either one end or the other end of the spool 14.
When the operation lever 18 is operated by the operator to the 1 st operation position, the pilot oil generated by the pilot pump 16 is directed to the spool 13 via the remote control valve 17 and the flow path 101, and the oil directed from the spool 13 to the remote control valve 17 via the flow path 102 is discharged to the tank 19. Thus, the pilot pressure acts on one end of the spool 14, and the spool 14 moves toward the other end side against the pressing force of the spring 15. Therefore, the flow rate of the hydraulic oil discharged from the hydraulic pump 11 toward the hydraulic actuator 12 increases, and the hydraulic actuator 12 is driven in one direction. For example, a hydraulic cylinder for driving a boom of a hydraulic excavator is extended, and the boom is operated.
When the operation lever 18 is operated by the operator to the 2 nd operation position, the pilot oil generated by the pilot pump 16 is directed to the spool 13 through the remote control valve 17 and the flow path 102, and the oil directed from the spool 13 to the remote control valve 17 through the flow path 101 is discharged to the tank 19. Thereby, the pilot pressure acts on the other end of the spool 14, and the spool 14 moves toward one end side. Therefore, the flow rate of the hydraulic oil discharged from the hydraulic pump 11 and directed to the hydraulic actuator 12 decreases, and the hydraulic actuator 12 is stopped.
In such a hydraulic circuit 10, there is a case where it is required that the movement of the spool 14 in one direction along the axial direction is performed rapidly and the movement in the other direction is performed slowly. For example, a front link mechanism (a boom, an arm, and a bucket) that is attached to a work machine such as a hydraulic excavator and driven by using a hydraulic circuit has a relatively large weight. In this case, if the front link mechanism is suddenly stopped after being operated by the hydraulic pressure, a shock is generated due to a large inertial force of the front link mechanism, and the entire work machine may greatly swing. Since the operator cannot perform the next operation until the swing is settled, the efficiency of the work using the work machine is lowered. Therefore, in the hydraulic circuit 10 shown in fig. 1, a flow rate control valve (non-impact valve) 20 is provided in the middle of a flow path 101 that communicates the remote control valve 17 with the spool 13.
Fig. 2 is a hydraulic circuit diagram for explaining an example of the flow control valve 20. In the illustrated example, the flow rate control valve 20 is disposed between the 1 st fluid pressure element E1 and the 2 nd fluid pressure element E2, and allows the fluid flowing from the 1 st fluid pressure element E1 to the 2 nd fluid pressure element E2 to flow rapidly and the fluid flowing from the 2 nd fluid pressure element E2 to the 1 st fluid pressure element E1 to flow slowly. When the flow rate control valve 20 is incorporated in the hydraulic circuit 10 shown in fig. 1, for example, the 1 st fluid pressure element E1 is the remote control valve 17, and the 2 nd fluid pressure element E2 is the spool 13. However, the present invention is not limited to this, and the 1 st fluid pressure element E1 and the 2 nd fluid pressure element E2 connected to the flow rate control valve 20 may be other fluid pressure elements, such as a hydraulic pressure element and a pneumatic pressure element.
The flow rate control valve 20 shown in fig. 2 includes a throttle portion 22, a control valve 24, and a check valve 28. Note that, in fig. 2, the throttle section 22, the control valve 24, the check valve 28, and the flow paths 103 and 104 are conceptually illustrated in terms of their functions.
The orifice 22 is provided in the middle of the flow path 103 that connects the 1 st fluid pressure element E1 and the 2 nd fluid pressure element E2, and restricts the flow rate of oil (fluid) flowing through the flow path 103 per unit time.
The control valve 24 controls the flow rate per unit time of the oil flowing through the flow path 103. The control valve 24 changes the cross-sectional area of the flow path 103 in accordance with the difference between the pressure of the oil at the position P1 of the throttle portion 22 on the 1 st fluid pressure element E1 side and the pressure of the oil at the position P2 of the throttle portion 22 on the 2 nd fluid pressure element E2 side in the flow path 103, thereby changing the flow rate of the oil flowing through the flow path 103 per unit time. In the illustrated example, when the pressure of the oil at the position P1 and the pressure of the oil at the position P2 are equal, the cross-sectional area of the flow passage 103 in the control valve 24 becomes maximum. In the present embodiment, the opening area of the opening 52 of the passage 51 of the 1 st valve member 50 described later is maximized. When the pressure of the oil at the position P2 is higher than the pressure of the oil at the position P1, the control valve 24 reduces the cross-sectional area of the flow path 103, thereby reducing the flow rate of the oil flowing through the flow path 103 per unit time. In the present embodiment, the opening 52 is partially closed by the end 64 of the 2 nd valve member 60 by the 2 nd valve member 60 moving to approach the 1 st valve member 50, which will be described later. Therefore, the control valve 24 functions as an additional throttle portion that restricts the flow rate per unit time of the oil flowing through the flow path 103. In particular, the control valve 24 functions as a variable throttle valve capable of continuously changing the cross-sectional area of the flow path 103.
A check valve 28 is provided in the middle of the flow path 104, and the flow path 104 branches from a position P3 on the 1 st fluid pressure element E1 side of the control valve 24 in the flow path 103, bypasses the throttle section 22 and the control valve 24, and merges with the flow path 103 at a position P4 on the 2 nd fluid pressure element E2 side of the throttle section 22. That is, the check valve 28 is provided in parallel with the throttle portion 22 and the control valve 24. In the present embodiment, the 1 st valve member 50 having the 1 st contact portion 53 described later functions as the check valve 28. The oil that has flowed into the check valve 28 from the position P3 through the flow path 104 flows toward the position P4 through the check valve 28. On the other hand, the flow of the oil flowing from the position P4 to the check valve 28 through the flow path 104 is blocked by the check valve 28 and cannot proceed to the position P3.
In the flow rate control valve 20 shown in fig. 2, the oil flowing from the 1 st fluid pressure element E1 to the 2 nd fluid pressure element E2 flows along the flow path 103 to the position P3. The check valve 28 allows the flow of oil from the position P3 toward the position P4 via the flow path 104. The throttle portion 22 and the control valve 24 also permit the flow of oil from the position P3 toward the position P4 via the flow path 103, the flow rate of which per unit time is restricted by the throttle portion 22. Therefore, the oil from the position P3 to the position P4 mainly flows through the flow path 104, i.e., through the check valve 28. Thereafter, the oil flows from the position P4 along the flow path 103 toward the 2 nd fluid pressure element E2.
The oil heading from the 2 nd fluid pressure element E2 to the 1 st fluid pressure element E1 is heading toward the position P4 along the flow path 103. Here, the check valve 28 does not allow the oil to flow from the position P4 toward the position P3 through the flow path 104. In this case, the oil from the position P4 toward the position P3 flows in the throttle portion 22. Here, the flow rate per unit time of the oil flowing through the throttle portion 22 is limited. Accordingly, a difference occurs between the pressure of the oil at the positions P2 and P4 of the throttle portion 22 on the 2 nd fluid pressure element E2 side and the pressure of the oil at the positions P1 and P3 of the throttle portion 22 on the 1 st fluid pressure element E1 side (control valve 24 side). Specifically, the pressure of the oil at positions P2, P4 is greater than the pressure of the oil at positions P1, P3. The pressure of the oil at the positions P2, P4 is introduced into the control valve 24. Thereby, the control valve 24 reduces the cross-sectional area of the flow path 103 to reduce the flow rate per unit time of the oil flowing through the flow path 103. At this time, the control valve 24 functions as an additional throttle unit, and restricts the flow rate per unit time of the oil flowing through the control valve 24. That is, the flow rate per unit time of the oil whose flow rate per unit time is restricted by the throttle portion 22 is further restricted by the control valve 24.
When the oil flows from the 1 st fluid pressure element E1 to the 2 nd fluid pressure element E2, the check valve 28 allows the oil to flow, and therefore the oil passes through the flow control valve 20 quickly. When the 1 st fluid pressure element E1 is the remote control valve 17 and the 2 nd fluid pressure element E2 is the spool 13, the pilot oil from the remote control valve 17 to the spool 13 passes through the flow control valve 20 and the spool 13 is rapidly operated. Therefore, the flow rate of the hydraulic oil discharged from the hydraulic pump 11 toward the hydraulic actuator 12 rapidly increases.
When the oil flows from the 2 nd fluid pressure element E2 to the 1 st fluid pressure element E1, the check valve 28 does not allow the oil to flow. Thus, the flow rate of oil per unit time is restricted by the throttle portion 22, and the flow rate per unit time is further restricted in the control valve 24. When the 1 st fluid pressure element E1 is the remote control valve 17 and the 2 nd fluid pressure element E2 is the spool 13, the flow rate of oil per unit time from the spool 13 to the remote control valve 17 is greatly restricted by the flow rate control valve 20. Thereby, the spool 13 operates at a slow speed. Therefore, the flow rate of the hydraulic oil discharged from the hydraulic pump 11 toward the hydraulic actuator 12 decreases at a slow rate.
In the example shown in fig. 1 and 2, when the hydraulic oil starts to be delivered to the hydraulic actuator 12, the flow rate of the hydraulic oil to the hydraulic actuator 12 can be rapidly increased. This can suppress occurrence of an operation delay in the hydraulic actuator 12 when the drive of the hydraulic actuator 12 is started. Therefore, when the driving of the hydraulic actuator 12 is started, it is possible to prevent the operator who operates the control lever 18 from feeling a sense of incongruity or from performing an unnecessary operation of the control lever 18 in order to further operate the hydraulic actuator 12.
On the other hand, when the supply of the hydraulic oil to the hydraulic actuator 12 is stopped, the flow rate of the hydraulic oil to the hydraulic actuator 12 can be decreased at a slow rate. This effectively suppresses sudden stop of the hydraulic actuator 12 and occurrence of shock in the work machine due to a large inertial force of the front link mechanism. Therefore, the entire work machine is prevented from greatly swinging, and the operator can quickly perform the next operation. That is, the work efficiency of the work machine can be effectively improved.
Next, an example of a specific structure of the flow rate control valve 20 according to the present embodiment will be described in detail with reference to fig. 3 and 4. Fig. 3 is a longitudinal sectional view showing an example of the flow rate control valve 20, and fig. 4 is a perspective view showing a shape of the 2 nd contact portion 65 of the 2 nd valve member 60 of the flow rate control valve 20.
In the example shown in fig. 3, the flow rate control valve 20 includes a housing 30 and a valve structure 40, and the housing 30 includes: two ports 30a, 30 b; and an internal space S having a shape of a stepped portion 33, 38 and connected to the two ports 30a, 30b, and the valve structure 40 is held in the housing 30. In particular, the housing 30 has: two ports 30a, 30 b; and an internal space S having a shape of the 1 st step portion 33 and the 2 nd step portion 38, connected to the two ports 30a, 30 b. The valve structure 40 includes: a throttle 62 provided in a 1 st flow path described later that connects the two ports 30a and 30 b; a 1 st contact portion 53 having a surface 53a not parallel to the moving direction and capable of blocking a 2 nd flow path described later by contacting with the step portions 33, 38 of the housing 30; and a pressing member 70 that presses the 1 st contact portion 53 so that the 1 st contact portion 53 can contact the step portions 33, 38 of the housing 30, and the valve structure 40 is movably housed in the internal space S of the housing 30. The valve structure 40 includes: a 1 st valve member (first valve member) 50 and a 2 nd valve member (second valve member) 60 movably housed in the housing 30; and a pressing member 70 disposed between the 1 st valve member 50 and the 2 nd valve member 60. In the illustrated example, the 1 st contact portion 53 is formed in the 1 st valve member 50, the throttle portion 62 is formed in the 2 nd valve member 60, and the pressing member 70 presses the 1 st valve member 50 and the 2 nd valve member 60 so as to separate the 1 st valve member 50 and the 2 nd valve member 60 from each other. Hereinafter, each constituent element of the flow rate control valve 20 will be described. In fig. 3, a direction along the central axis a of the flow control valve 20 is referred to as an axial direction da, a side of the outer member 90 (a lower side in fig. 3) with respect to the flow control valve 20 along the axial direction da is referred to as "one side", and a side opposite to the "one side" (an upper side in fig. 3) is referred to as "the other side". In the example shown in fig. 3, the flow rate control valve 20 communicates with the 1 st fluid pressure element E1 at one side portion thereof and communicates with the 2 nd fluid pressure element E2 at the other side portion thereof.
The housing 30 functions as a housing that defines an internal space S. The housing 30 has two ports, a 1 st port 30a and a 2 nd port 30 b. In the illustrated example, the housing 30 includes: a 1 st housing 31 having a 1 st port 30 a; and a 2 nd housing 35 having a 2 nd port 30b and coupled to the 1 st housing 31, the inner space S being defined by the 1 st housing 31 and the 2 nd housing 35. The housing 30 has stepped portions 33 and 38 to which the 1 st contact portion 53 comes into contact and separates with the movement of the valve structure 40. Thus, the housing 30 has: two ports 30a, 30 b; and an internal space S having a shape of a stepped portion 33, 38, connected to the two ports 30a, 30 b. The case 30 is formed by dividing the case 30 into the 1 st case 31 and the 2 nd case 35, and the case 30 can be easily manufactured. The housing 30 is formed with a 1 st screw portion 41, and the flow rate control valve 20 (housing 30) is attached to the outer member 90 by screwing the 1 st screw portion 41 to an outer screw portion 94 formed in a recess 92 of the outer member 90. The casing 30 has a substantially cylindrical (cylindrical) shape as a whole, and has a substantially circular shape when viewed along the axial direction da. The outer member 90 is part of any hydraulic device. The external member 90 is a member that communicates with the 1 st fluid pressure element E1 (remote control valve 17). In the illustrated example, the 1 st port 30a communicates with the 1 st fluid pressure element E1, and the 2 nd port 30b communicates with the 2 nd fluid pressure element E2.
The 1 st housing 31 has a small diameter portion 31a and a large diameter portion 31b located on the other side with respect to the small diameter portion 31 a. The small diameter portion 31a has a relatively small diameter with respect to the diameter of the large diameter portion 31 b. A 1 st screw portion 41 is formed on one side of the outer periphery of the small diameter portion 31 a. The 1 st screw part 41 is constituted by an external thread. The large diameter portion 31b has a relatively large diameter with respect to the diameter of the small diameter portion 31 a. The small diameter portion 31a and the large diameter portion 31b each have a substantially cylindrical shape.
A through hole 32 penetrating from one side to the other side is formed in the 1 st case 31. In the illustrated example, the through-hole 32 is formed by a combination of 3 holes (32a to 32c) having diameters different from each other so as to become larger in stages from one side to the other side. Among them, a hole having the smallest cross-sectional dimension (diameter) and opening at one end surface of the 1 st shell 31 is set as the small-diameter hole 32a, a hole having the largest diameter and opening at the other end surface of the 1 st shell 31 is set as the large-diameter hole 32c, and a hole having a diameter between the diameter of the small-diameter hole 32a and the diameter of the large-diameter hole 32c and located between the small-diameter hole 32a and the large-diameter hole 32c along the axial direction da is set as the medium-diameter hole 32 b. In the illustrated example, the small-diameter hole 32a constitutes the 1 st port 30 a. The holes 32a to 32c are arranged coaxially with each other. A 2 nd screw portion 42 is formed on the inner peripheral surface of the through hole 32. In particular, the 2 nd screw part 42 is formed on the inner peripheral surface of the large diameter hole 32 c. The 2 nd screw part 42 is constituted by an internal thread. The other end of the small-diameter hole 32a forms a 1 st step portion 33 that contacts a 1 st contact portion 53, which will be described later, of the 1 st valve member 50. The intermediate diameter hole 32b may be omitted. That is, the through hole 32 may have a small diameter hole 32a and a large diameter hole 32 c.
The 2 nd housing 35 is formed in a substantially cylindrical shape as a whole, and is attached to the 1 st housing 31 at one side portion thereof. A 3 rd screw part 43 is formed at one side portion of the outer circumference of the 2 nd housing 35, and a 4 th screw part 44 is formed at the other side portion of the outer circumference of the 2 nd housing 35. The 3 rd and 4 th screw parts 43 and 44 are each constituted by an external thread. In the illustrated example, one end of the 2 nd casing 35 is positioned in the through hole 32 (large diameter hole 32c) of the 1 st casing 31, and the 3 rd screw portion 43 of the 2 nd casing 35 is screwed to the 2 nd screw portion 42 of the 1 st casing 31, whereby the 2 nd casing 35 is attached to the 1 st casing 31.
A through hole 36 penetrating from one side to the other side is formed in the 2 nd housing 35. The through hole 36 is formed by a combination of two holes (36a, 36b) having different diameters from each other. Among them, a hole having a relatively small diameter on the other side is set as the small-diameter hole 36a, and a hole having a relatively large diameter on one side of the small-diameter hole 36a is set as the large-diameter hole 36 b. In the illustrated example, the small-diameter hole 36a constitutes the 2 nd port 30 b. One end of the small-diameter hole 36a is an opening 37 that opens into the large-diameter hole 36 b. The large-diameter hole 36b opens at an end surface of the 2 nd housing 35. A 2 nd step portion 38 is formed at the position closest to the other side of the large diameter hole 36b, and the 2 nd step portion 38 has a bearing surface for receiving a 2 nd contact portion 65, which will be described later, of the 2 nd valve member 60. The support surface is formed by a surface facing one side and orthogonal to the central axis a.
In the example shown in fig. 3, the valve structure 40 is disposed in the through hole 32 of the 1 st case 31 and the through hole 36 of the 2 nd case 35. That is, the 1 st valve member 50, the 2 nd valve member 60, and the pressing member 70 are disposed in the through holes 32 and 36. Thus, the valve structure 40 is disposed between the 1 st port 30a and the 2 nd port 30b of the housing 30. The internal space S is defined by the middle diameter hole 32b and the large diameter hole 32c of the 1 st case 31 and the large diameter hole 36b of the 2 nd case 35.
A seal member 75 is disposed between the 1 st case 31 and the 2 nd case 35. Further, a seal member 77 is disposed between the casing 30 and the exterior member 90, particularly between the 1 st casing 31 and the exterior member 90. The seal members 75 and 77 are formed of, for example, O-rings, and prevent oil from leaking between the 1 st casing 31 and the 2 nd casing 35 or between the casing 30 and the outer member 90.
The 1 st valve member (valve member) 50 is a member that: functions as the control valve 24 described with reference to fig. 2 in cooperation with the 2 nd valve member 60, and functions as the check valve 28 described with reference to fig. 2 in cooperation with the 1 st step portion 33 of the 1 st housing 31. In the example shown in fig. 3, the 1 st valve member 50 is configured by a combination of 3 portions (50a to 50c) having mutually different cross-sectional dimensions (diameters) so as to become larger in stages from one side to the other side. That is, the 1 st valve member 50 has: a small diameter portion 50a located at the most lateral position along the axial direction da and having the smallest diameter; a large diameter portion 50c located at the other side and having the largest diameter; and a middle diameter part 50b located between the small diameter part 50a and the large diameter part 50c and having a diameter between the diameter of the small diameter part 50a and the diameter of the large diameter part 50 c. The small diameter portion 50a, the intermediate diameter portion 50b, and the large diameter portion 50c each have a circular profile when viewed from the axial direction da. The large diameter portion 50c of the 1 st valve member 50 is movable in the axial direction da while contacting the inner circumferential surface of the large diameter hole 36b of the 2 nd housing 35 via an oil film.
The small diameter portion 50a has a substantially cylindrical shape with one side thereof closed. A plurality of passages 51 formed as through holes are provided in a side surface of the small diameter portion 50a extending in the axial direction da. The passage 51 has an opening 52 that opens into a central passage 54 described later. The opening 52 is formed on the side of the 1 st contact portion 53 described later in the radial direction from the central passage 54. In the illustrated example, the passage 51 communicates with the 1 st fluid pressure element E1 via the 1 st port 30a (small diameter hole 32a) of the 1 st housing 31, the recess 92 of the outer member 90, and the flow path 96.
A 1 st contact portion (contact portion) 53 is provided in a portion of the outer peripheral surface of the 1 st valve member 50 between the small diameter portion 50a and the medium diameter portion 50b, and the 1 st contact portion (contact portion) 53 has a seat surface that is not parallel to the axial direction da, which is the moving direction of the 1 st valve member 50. The seat surface extends in a direction inclined with respect to both the moving direction of the 1 st valve member 50 and a direction orthogonal to the moving direction. More specifically, the seat surface is formed by a part of a conical surface obtained by rotating a straight line passing through a point on the central axis a on the side of the intermediate diameter portion 50b and inclined with respect to the central axis a around the central axis a. The small diameter portion 50a and the middle diameter portion 50b of the 1 st valve member 50 are connected by a 1 st contact portion 53. The 1 st contact portion (contact portion) 53 is configured to be able to contact the 1 st port 30a of the housing 30 in the internal space S of the housing 30. As will be described later, even if the valve structure 40 is reversed in the moving direction of the 1 st valve member 50, the housing 30 of the flow rate control valve 20 can house the valve structure 40. In this case, the 1 st contact portion (contact portion) 53 is configured to be able to contact the 2 nd port 30b of the housing 30 in the internal space S of the housing 30. Therefore, the valve structure 40 includes: a 1 st contact portion 53 that is contactable with the one ports 30a, 30b of the housing 30 in the internal space S of the housing 30; and a throttle portion 62 disposed between the one ports 30a, 30b and the other ports 30b, 30 a.
When the 1 st valve member 50 moves to one side in the axial direction da and the 1 st contact portion 53 contacts the 1 st step portion 33 of the 1 st housing 31 over the entire circumference around the center axis a, the flow of oil between the outer circumference of the 1 st valve member 50 and the inner circumference of the through hole 32 of the 1 st housing 31, particularly between the 1 st contact portion 53 and the 1 st step portion 33, is inhibited. On the other hand, when the 1 st valve member 50 moves to the other side in the axial direction da and the 1 st contact portion 53 is separated from the 1 st stepped portion 33, the oil is allowed to flow between the outer periphery of the 1 st valve member 50 and the inner periphery of the through hole 32 of the 1 st housing 31.
The 1 st valve member 50 has a central passage 54 that holds a shaft portion 61, described later, of the 2 nd valve member 60. A large-diameter hole 55 that opens to the other side and a central passage 54 that opens to the large-diameter hole 55 are provided inside the 1 st valve member 50. The central passage 54 and the large-diameter hole 55 each have a circular-shaped profile as viewed in the axial direction da. The large-diameter hole 55 has a diameter larger than that of the central passage 54. In the illustrated example, the central passage 54 extends across the small diameter portion 50a and the medium diameter portion 50b along the central axis a, and the large diameter hole 55 extends along the central axis a inside the large diameter portion 50 c. In the illustrated example, the center passage 54 connects one side and the other side in the moving direction of the 1 st contact portion 53, one side of the center passage 54 is closed, and the other side of the center passage 54 is opened.
A hole 56 is formed in the large diameter portion 50c of the 1 st valve member 50 so as to extend from the outer peripheral surface of the large diameter portion 50c to the inner peripheral surface (large diameter hole 55). The cross-sectional area of the orifice 56 has an area that does not substantially limit the extent of the flow rate of oil per unit time. For example, the cross-sectional area of the hole 56 is preferably sufficiently larger than the cross-sectional area of a later-described throttle portion 62 of the 2 nd valve member 60. A 1 st support portion 57 is formed at a step portion connecting the central passage 54 and the large diameter hole 55, and the 1 st support portion 57 supports the pressing member 70 and receives the pressing force of the pressing member 70. The 1 st support portion 57 is formed of a surface orthogonal to the central axis a.
The 2 nd valve member (the other valve member) 60 has a shaft portion 61 and a 2 nd contact portion 65 located on the other side of the shaft portion 61. The shaft portion 61 is formed in a substantially cylindrical shape as a whole, and extends in the axial direction da. In the illustrated example, a central axis extending in the longitudinal direction of the shaft portion 61 coincides with the central axis a. That is, the central axis a may be said to be the central axis of the shaft portion 61. The shaft portion 61 is formed integrally with the 2 nd contact portion 65, and the shaft portion 61 is movable in the axial direction da in the central passage 54 of the 1 st valve member 50. A hollow portion 63 is formed inside the shaft portion 61. The hollow portion 63 is formed as a hole that is open on one side and closed on the other side. That is, one side of the hollow portion 63 in the moving direction of the shaft portion 61 is open, and the other side is closed. The hollow portion 63 extends along the axial direction da including the central axis a. A cross section of the hollow portion 63 orthogonal to the central axis a has a circular shape having mutually the same size at each position along the axial direction da. The 2 nd valve member 60 is movably held in the central passage 54 of the 1 st valve member 50. In particular, one end 64 (distal end of the shaft 61) of the 2 nd valve member 60 is held in the central passage 54. In other words, a part of the shaft portion 61 including the one end portion 64 is inserted into the central passage 54. Thereby, the 2 nd valve member 60 is movable in the axial direction da with respect to the 1 st valve member 50 toward the opening 52 of the passage 51 of the 1 st valve member 50 (toward one side) and away from the opening 52 (toward the other side). The opening 52 is partially closed by the end 64 in accordance with the movement of the 2 nd valve member 60. In addition, since the opening 52 is partially closed, the opening area of the opening 52 changes. Therefore, the opening area of the opening 52 of the oil flow path changes as the 2 nd valve member 60 moves closer to the 1 st valve member 50.
A throttle portion 62 communicating with the hollow portion 63 is formed in the shaft portion 61 of the 2 nd valve member 60. The throttle portion 62 is formed at a position exposed from the central passage 54 when the 2 nd valve member 60 is located at the most lateral position. That is, even when the 2 nd valve member 60 is located at any position within its movement range, the throttle portion 62 is always exposed from the central passage 54. In the illustrated example, the throttle portion 62 extends in a direction orthogonal to the central axis a. That is, the throttle portion 62 is formed radially from the hollow portion 63. A cross section of the throttle portion 62 orthogonal to the direction in which the throttle portion 62 extends has a circular shape, and has the same size as each other at each position along the direction in which the throttle portion 62 extends. Further, the choke portion 62 is not limited to this, and may extend in a direction inclined with respect to both the direction in which the central axis a extends (the axial direction da) and the direction orthogonal to the central axis a. The cross section of the throttle portion 62 may have different dimensions at positions along the direction in which the throttle portion 62 extends. For example, the cross section of the throttle portion 62 may have a smaller size than the cross section of the other range in a partial range along the direction in which the throttle portion 62 extends. The minimum cross-sectional area of the orifice 62 is set to a level that can limit the flow rate per unit time of the oil flowing through the orifice 62.
The inner space S of the housing 30 is divided by the 2 nd valve member 60 into a 1 st pressure chamber C1 including the hollow portion 63 and a 2 nd pressure chamber C2 communicating with the hollow portion 63 via the throttle portion 62. In the illustrated example, the 1 st pressure chamber C1 is a space inside the hollow portion 63 and the central passage 54, and the 2 nd pressure chamber C2 is a space outside the 2 nd valve member 60 in the internal space S. As described above, the opening 52 of the passage 51 opens into the central passage 54. Therefore, the opening 52 may be said to be opened in the 1 st pressure chamber C1. In the illustrated example, the 1 st pressure chamber C1 communicates with the 1 st port 30a (small diameter hole 32a) of the 1 st casing 31, the recess 92 of the outer member 90, and the flow path 96 via the opening 52.
The 2 nd contact portion 65 has an outer dimension larger than an outer dimension of the shaft portion 61 and an inner dimension of the central passage 54 when viewed in the axial direction da. Thus, the 2 nd contact portion 65 cannot enter the central passage 54. The 2 nd contact portion 65 has an outer dimension larger than the inner dimension of the small diameter hole 36a of the through hole 36 and smaller than the inner dimension of the large diameter hole 36b when viewed in the axial direction da. Therefore, the 2 nd contact portion 65 can enter the large diameter hole 36b, but cannot enter the small diameter hole 36 a. That is, when the 2 nd valve member 60 moves toward the other side, the 2 nd contact portion 65 contacts the 2 nd step portion 38 connecting the small diameter hole 36a and the large diameter hole 36b, and the 2 nd valve member 60 cannot move further toward the other side.
The surface of the 2 nd contact portion 65 facing one side includes a 2 nd support portion 67, and the 2 nd support portion 67 supports the pressing member 70 and receives the pressing force of the pressing member 70. In the illustrated example, the pressing member 70 is a coil spring, and is disposed between the 2 nd support portion 67 and the 1 st support portion 57 in a compressed state. Therefore, the pressing member 70 generates a pressing force in a direction in which the pressing member 70 extends, in other words, in a direction in which the 1 st valve member 50 and the 2 nd valve member 60 are separated from each other due to its elastic force. The coil spring constituting the pressing member 70 is disposed so as to surround the shaft portion 61. The pressing member 70 is not limited to a coil spring, and various members capable of generating a pressing force can be used.
As shown in fig. 4, the 2 nd contact portion 65 has a notch portion 66 in an outer peripheral portion. In the illustrated example, the 2 nd contact portion 65 has two cutout portions 66 so as to be symmetrical with respect to the central axis a. The notch 66 extends inward from the outer peripheral portion of the 2 nd contact portion 65 beyond the contour of the opening 37 of the small diameter hole 36a of the 2 nd housing 35 when viewed in the axial direction da. Thereby, a gap 81 is formed between the notch 66 and the opening 37. The gap 81 has an opening area that does not substantially limit the degree of the flow rate per unit time of the oil flowing through the gap 81. In the illustrated example, each cutout 66 is formed by partially removing the outer peripheral portion of the 2 nd contact portion 65 linearly as viewed from the axial direction da, but the specific shape of the cutout 66 is not limited thereto. For example, the notch 66 may be formed in a groove shape extending inward from the outer peripheral portion of the 2 nd contact portion 65. The 2 nd contact portion 65 may have 1 notch portion 66, or 3 or more notch portions 66. Instead of the notch 66, the 2 nd contact portion 65 may be provided with a through hole penetrating from one side to the other side, and the through hole may be a gap 81.
Next, the operation of the flow rate control valve 20 will be described with reference to fig. 3, 5, and 6.
When the remote control valve 17 is not operated and the pilot pressure from the pilot pump 16 does not act on the flow control valve 20, the pressure of the oil in the 1 st pressure chamber C1 is equal to the pressure of the oil in the 2 nd pressure chamber C2. As shown in fig. 3, the 1 st valve member 50 is located on the opposite side (one side) from the 2 nd valve member 60 due to the pressing force of the pressing member 70. At this time, the 1 st contact portion 53 of the 1 st valve member 50 is pressed against the 1 st step portion 33 of the 1 st housing 31. In addition, the 2 nd valve member 60 is positioned on the opposite side (the other side) from the 1 st valve member 50 by the pressing force of the pressing member 70. At this time, the 2 nd contact portion 65 of the 2 nd valve member 60 is pressed against the bearing surface of the 2 nd stepped portion 38 of the 2 nd housing 35. In the illustrated example, at this time, the opening portion 52 of the passage 51 is not closed by the end portion 64 of the 2 nd valve member 60, and the opening portion 52 has an opening area of a degree that does not substantially restrict the flow rate per unit time of the oil flowing through the opening portion 52.
In a state where the 1 st contact portion 53 of the 1 st valve member 50 is in contact with the housing 30 (the 1 st step portion 33), a 1 st flow path (flow path) including the throttle portion 62 is formed between the 1 st port 30a and the 2 nd port 30 b. Specifically, a 1 st flow path including the passage 51, the central passage 54, the hollow portion 63, the throttle portion 62, and the gap 81 is formed between the 1 st port 30a and the 2 nd port 30 b. Therefore, in a state where the 1 st contact portion 53 of the 1 st valve member 50 is in contact with the housing 30, the flow path (the 2 nd flow path, the other flow path) bypassing the throttle portion 62 is blocked, and the oil flowing between the 1 st port 30a and the 2 nd port 30b inevitably passes through the throttle portion 62.
When the control lever 18 of the remote control valve 17 is operated by the operator and the pilot pressure from the pilot pump 16 is applied to the flow rate control valve 20 via the 1 st fluid pressure element E1 (remote control valve 17), the pilot pressure is introduced into the 1 st pressure chamber C1 via the flow path 96, the recess 92, the 1 st port 30a (small-diameter hole 32a), and the passage 51. At this time, the throttle 62 restricts the flow rate per unit time of the oil flowing through the throttle 62. Thus, the pressure of the oil in the 1 st pressure chamber C1 is higher than the pressure of the oil in the 2 nd pressure chamber C2. Specifically, due to the flow rate restricting effect of the throttle 62, the rate of increase in the pressure of the oil in the 2 nd pressure chamber C2 is slower than the rate of increase in the pressure of the oil in the 1 st pressure chamber C1 and the 1 st port 30a, and a difference (pressure difference) is generated between the pressure of the oil in the 1 st pressure chamber C1 and the 1 st port 30a and the pressure of the oil in the 2 nd pressure chamber C2.
When the differential pressure exceeds a certain level, the force of the pressing member 70 that presses the 1 st valve member 50 toward the 2 nd valve member 60 (the other side) is larger than the force of the pressing member 50 that presses the 1 st valve member 50 toward the side opposite to the 2 nd valve member 60 (the one side), and the 1 st valve member 50 moves toward the 2 nd valve member 60. Thereby, the 1 st contact portion 53 of the 1 st valve member 50 is separated from the 1 st step portion 33 of the 1 st housing 31. At this time, the 1 st port 30a and the 2 nd pressure chamber C2 communicate via the gap 83 between the 1 st contact portion 53 and the 1 st step portion 33. Therefore, as shown in fig. 5, the oil flowing from the 1 st fluid pressure element E1 to the 1 st port 30a flows through the gap 83, the hole 56, the large diameter hole 55, the gap 81, and the 2 nd port 30b (the small diameter hole 36a) in this order toward the 2 nd fluid pressure element E2. Thereby, the 2 nd fluid pressure element E2 operates.
When the 1 st contact portion 53 of the 1 st valve member 50 is separated from the 1 st step portion 33 of the 1 st housing 31, the oil rapidly flows from the 1 st port 30a into the 2 nd pressure chamber C2 through the clearance 83, and a difference (differential pressure) between the pressure of the oil in the 1 st pressure chamber C1 and the 1 st port 30a and the pressure of the oil in the 2 nd pressure chamber C2 becomes small. As the differential pressure decreases, the force with which the 1 st valve member 50 is pushed toward the 2 nd valve member 60 side decreases, and the 1 st valve member 50 is pushed back toward the side opposite to the 2 nd valve member 60 by the pushing force of the pushing member 70. At this time, since the clearance 83 becomes small, a pressure difference is newly generated between the 1 st pressure chamber C1 and the 1 st port 30a and the 2 nd pressure chamber C2, whereby the 1 st valve member 50 is pushed toward the 2 nd valve member 60 side against the pressing force of the pressing member 70. Therefore, the 1 st valve member 50 is stopped at a position where the pressing force of the pressing member 70 that presses the 1 st valve member 50 to the side opposite to the 2 nd valve member 60 is balanced with the pressing force that presses the 1 st valve member 50 to the other side due to the pressure difference generated between the 1 st pressure chamber C1 and the 1 st port 30a and the 2 nd pressure chamber C2. Further, due to a slight variation in the differential pressure generated between the 1 st pressure chamber C1 and the 1 st port 30a and the 2 nd pressure chamber C2, the 1 st valve member 50 may not be completely stopped, and its position may vary slightly.
In a state where the 1 st contact portion 53 of the 1 st valve member 50 is separated from the housing 30 (the 1 st step portion 33), a 2 nd flow path (another flow path) bypassing the throttle portion 62 is formed between the 1 st port 30a and the 2 nd port 30 b. Specifically, a 2 nd flow path including the gap 83, the hole 56, the large-diameter hole 55, and the gap 81 is formed between the 1 st port 30a and the 2 nd port 30 b. Therefore, in a state where the 1 st contact portion 53 of the 1 st valve member 50 is separated from the housing 30, most of the oil flowing between the 1 st port 30a and the 2 nd port 30b flows without passing through the throttle portion 62. Also in this case, a part of the oil flowing between the 1 st port 30a and the 2 nd port 30b can pass through the throttle portion 62.
When the operation lever 18 of the remote control valve 17 is operated by the operator and the 1 st pressure chamber C1 and the 1 st port 30a communicate with the tank 19 via the recess 92, the flow path 96, and the 1 st fluid pressure element E1 (remote control valve 17), the differential pressure between the 1 st pressure chamber C1 and the 1 st port 30a and the 2 nd pressure chamber C2 sharply decreases. That is, the pressing force for pressing the 1 st valve member 50 toward the 2 nd valve member 60 side is abruptly reduced. Thereby, the 1 st valve member 50 is moved to the opposite side of the 2 nd valve member 60 by the pressing force of the pressing member 70, the 1 st contact portion 53 of the 1 st valve member 50 is pressed against the 1 st step portion 33 of the 1 st housing 31, and the gap 83 is closed. Therefore, the 1 st pressure chamber C1 and the 2 nd pressure chamber C2 communicate with each other only by the throttle portion 62. Thus, the pressure of the oil in the 2 nd pressure chamber C2 is higher than the pressure of the oil in the 1 st pressure chamber C1. Specifically, due to the flow rate restriction effect of the throttle 62, the speed of decrease in the pressure of the oil in the 2 nd pressure chamber C2 is slower than the speed of decrease in the pressure of the oil in the 1 st pressure chamber C1, and a difference (differential pressure) is generated between the pressure of the oil in the 1 st pressure chamber C1 and the pressure of the oil in the 2 nd pressure chamber C2. Due to the pressing force caused by the pressure difference, as shown in fig. 6, the 2 nd valve member 60 moves toward (one side of) the 1 st valve member 50 against the pressing force of the pressing member 70.
The 2 nd valve member 60 moves so as to approach the 1 st valve member 50, and the flow path including the throttle portion 62 is partially closed. Specifically, the opening 52 of the passage 51 is partially closed by the end 64 of the 2 nd valve member 60 with the movement of the 2 nd valve member 60. At this time, as the differential pressure between the 1 st pressure chamber C1 and the 2 nd pressure chamber C2 increases, the difference between the pressing force toward the 1 st valve member 50 side by the differential pressure and the pressing force toward the side opposite to the 1 st valve member 50 side by the pressing member 70 increases, the 2 nd valve member 60 moves to one side, the end portion 64 greatly closes the opening portion 52, and the opening area of the opening portion 52 decreases. When the opening area of the opening 52 is reduced, the flow rate per unit time of the oil flowing through the opening 52 is restricted. Therefore, the opening 52 partially closed by the end 64 of the 2 nd valve member 60 functions as an additional throttle portion to the throttle portion 62.
When the opening area of the opening 52 is smaller than the cross-sectional area (minimum cross-sectional area) of the orifice 62, the flow rate per unit time of the oil flowing through the opening 52 is greatly restricted by the opening 52, and the oil flows from the 2 nd pressure chamber C2 into the 1 st pressure chamber C1 via the orifice 62. Accordingly, the pressure of the oil in the 1 st pressure chamber C1 increases, and the pressure difference between the 1 st pressure chamber C1 and the 2 nd pressure chamber C2 decreases. Thus, the difference between the pressing force toward the 1 st valve member 50 side by the pressure difference and the pressing force toward the side opposite to the 1 st valve member 50 side by the pressing member 70 is reduced, the closed region of the opening portion 52 where the 2 nd valve member 60 moves to the side (the other side) opposite to the 1 st valve member 50 side and is closed by the end portion 64 of the 2 nd valve member 60 is reduced, and the opening area of the opening portion 52 is increased. Therefore, the opening 52 of the passage 51 is partially closed by the end portion 64, and thereby the 2 nd valve member 60 is stopped at a position where the pressing force of the 2 nd valve member 60 to the 1 st valve member 50 side by the pressure difference generated between the 1 st pressure chamber C1 and the 2 nd pressure chamber C2 is balanced with the pressing force of the pressing member 70 toward the side opposite to the 1 st valve member 50 side. Further, due to a slight variation in the differential pressure generated between the 1 st pressure chamber C1 and the 2 nd pressure chamber C2, the 2 nd valve member 60 may not be completely stopped, and the position thereof may vary slightly. In addition, the end portion 64 of the 2 nd valve member 60 may temporarily and completely close the opening 52 in the middle of its movement. Therefore, in the present specification, "the opening 52 is partially closed" also includes a case where the opening 52 is temporarily and completely closed.
In the example described with reference to fig. 3, 5, and 6, the throttle unit 62 functions as the throttle unit 22 in the example described with reference to fig. 2. The opening 52 and the end 64 of the 2 nd valve member 60 function as the control valve 24 in the example described with reference to fig. 2. The 1 st contact portion 53 of the 1 st valve member 50 and the 1 st step portion 33 of the 1 st housing 31 function as the check valve 28 in the example described with reference to fig. 2. Thus, the flow rate control valve 20 allows the flow rate of the oil from the 1 st port 30a to the 2 nd port 30b, that is, the flow rate of the oil from the 1 st fluid pressure element E1 to the 2 nd fluid pressure element E2 to increase rapidly. On the other hand, the flow control valve 20 prevents the flow rate of the oil from the 2 nd port 30b to the 1 st port 30a, that is, the flow rate of the oil from the 2 nd fluid pressure element E2 to the 1 st fluid pressure element E1 from rapidly increasing. Therefore, in the example described with reference to fig. 1, the flow rate control valve 20 has a function (no-shock function) of reducing the occurrence of a shock caused by a large inertia force of the front link mechanism due to the hydraulic actuator 12 driven by the oil discharged from the hydraulic pump 11 being suddenly stopped by rapidly moving the spool 14 toward one end (right end) side along the axial direction thereof.
In the present embodiment, as shown in fig. 7, even if the valve structure 40 is reversed in the moving direction of the 1 st valve member 50, the housing 30 of the flow rate control valve 20 can house the valve structure 40. In this case, the opening 37 of the small-diameter hole 36a of the 2 nd housing 35 constitutes the 1 st stepped portion 33. In the case where the 1 st valve member 50 and the 2 nd valve member 60 are arranged in an inverted manner, the flow rate control valve 20 allows the flow rate of the oil from the 2 nd port 30b to the 1 st port 30a, that is, the flow rate of the oil from the 2 nd fluid pressure element E2 to the 1 st fluid pressure element E1 to be rapidly increased, contrary to the example described with reference to fig. 3, 5, and 6. On the other hand, the flow control valve 20 prevents the flow rate of the oil from the 1 st port 30a to the 2 nd port 30b, that is, the flow rate of the oil from the 1 st fluid pressure element E1 to the 2 nd fluid pressure element E2 from rapidly increasing. Therefore, in the flow rate control valve 20 of the present embodiment, a flow rate control valve that performs a function different from the example described with reference to fig. 3, 5, and 6 can be obtained only by inverting the 1 st valve member 50 and the 2 nd valve member 60 in the moving direction of the 1 st valve member 50. In particular, in the flow rate control valve 20 of the present embodiment, it is possible to obtain a flow rate control valve that can exhibit a non-impact function in the direction opposite to the example described with reference to fig. 3, 5, and 6 only by inverting the 1 st valve member 50 and the 2 nd valve member 60 in the moving direction of the 1 st valve member 50.
Here, the width (outer diameter) of the small diameter portion 50a of the 1 st valve member 50 along the direction orthogonal to the central axis a is W1The width (outer diameter) of the intermediate diameter portion 50b is W2W represents the width (outer diameter and maximum width) of the 2 nd contact portion 65 of the 2 nd valve member 603The width (inner diameter) of the small-diameter hole 32a of the 1 st housing 31 is W4The width (inner diameter) of the small-diameter hole 36a of the 2 nd housing 35 is W5. In the present embodiment, the width W4And width W5Average specific width W1Large and specific width W2Is small. In addition, the width W4And width W5Average specific width W3Is small. Thus, even if the 1 st valve member 50 and the 2 nd valve member 60 are reversed in the moving direction of the 1 st valve member 50, a flow rate control valve that can exhibit a non-impact function can be obtained. When the 1 st valve member 50 and the 2 nd valve member 60 are reversed, the width W is set so as to obtain a flow rate control valve having the same characteristics as those of the flow rate control valve 20 before the reversal4And width W5Are set to the same size as each other. On the other hand, when the 1 st valve member 50 and the 2 nd valve member 60 are reversed, the width W can be set so as to obtain a flow rate control valve having a characteristic different from that of the flow rate control valve 20 before the reversal4And width W5Are set to different sizes.
The flow rate control valve 20 of the present invention includes: a housing 30 having two ports 30a, 30b and an internal space S in a shape having steps 33, 38, connected to the two ports 30a, 30 b; and a valve structure 40 having a throttling portion 62, a contact portion 53, and a pressing member 70, the throttling portion 62 being provided in a flow path connecting the two ports 30a, 30b, the contact portion 53 having a surface 53a not parallel to the moving direction and being capable of blocking the other flow path by coming into contact with the step portions 33, 38, the pressing member 70 pressing the contact portion 53 so that the contact portion 53 can come into contact with the step portions 33, 38 of the housing 30, and the valve structure 40 being movably housed in the internal space S of the housing 30.
The flow rate control valve 20 of the present invention includes: a housing 30 having two ports 30a and 30b and an internal space S connecting the two ports 30a and 30 b; and a valve structure 40 having a contact portion 53 and a throttle portion 62, the contact portion 53 being capable of contacting the one ports 30a, 30b of the housing 30 in the internal space S of the housing 30, the throttle portion 62 being disposed between the one ports 30a, 30b and the other ports 30b, 30a, a flow path passing through the throttle portion 62 being formed between the two ports 30a, 30b in a state where the contact portion 53 of the valve structure 40 is in contact with the housing 30, and a flow path bypassing the throttle portion 62 being formed in a state where the contact portion 53 of the valve structure 40 is separated from the housing 30.
The flow rate control valve 20 of the present invention includes: a housing 30 having two ports 30a, 30b and an internal space S, which is in a shape having a 1 st step portion 33 and a 2 nd step portion 38, connected to the two ports 30a, 30 b; a 1 st valve member 50 movably housed in the internal space S of the housing 30, and including a 1 st contact portion 53, a central passage 54, and an opening portion 52, the 1 st contact portion 53 having a surface 53a that is not parallel to the moving direction and being capable of contacting the 1 st step portion 33, the central passage 54 connecting one side and the other side of the 1 st contact portion 53 in the moving direction, the one side being closed, the other side being open, the opening portion 52 being formed in the radial direction from the central passage 54 on the one side of the 1 st contact portion 53; a 2 nd valve member 60 movably housed in the internal space S of the housing 30, and including a 2 nd contact portion 65, a shaft portion 61, a hollow portion 63, and a throttle portion 62, the 2 nd contact portion 65 being capable of contacting the 2 nd step portion 38 of the housing 30, the shaft portion 61 being formed integrally with the 2 nd contact portion 65 and being movable in the axial direction da in the central passage 54 of the 1 st valve member 50, one side of the hollow portion 63 in the moving direction of the shaft portion 61 being open, the other side being closed, the throttle portion 62 being formed in the radial direction from the hollow portion 63; and a pressing member 70 separating the 1 st valve member 50 and the 2 nd valve member 60.
The work machine of the present invention includes the flow rate control valve 20.
According to the flow rate control valve 20 and the working machine, the flow path including the throttle portion 62 and the flow path bypassing the throttle portion 62 can be switched between the state where the 1 st contact portion 53 of the valve member 50 is in contact with the housing 30 and the state where the 1 st contact portion 53 of the valve member 50 is separated from the housing 30. Therefore, different flow rate control functions can be provided to the flow rate control valve 20 in a state where the 1 st contact portion 53 of the valve member 50 is in contact with the housing 30 and in a state where the 1 st contact portion 53 of the valve member 50 is separated from the housing 30. In this case, since the 1 st contact portion 53 is separated from the housing 30, the flow path of the oil is instantaneously switched from the flow path including the throttle portion 62 to the flow path bypassing the throttle portion 62. Thus, it is possible to effectively prevent a response delay from being generated in the flow control valve 20. Further, by replacing at least a part of the valve structure 40 including the valve member 50, it is possible to further provide a different flow rate control function to the flow rate control valve 20 without replacing the housing 30. This can effectively reduce the number of replacement parts when changing the function of the flow control valve 20.
In the flow rate control valve 20 of the present invention, the contact portion 53 is formed in the valve member 50, the throttle portion 62 is formed in the other valve member 60, and the pressing member 70 presses the valve member 50 and the other valve member 60 so as to separate the valve member 50 and the other valve member 60 from each other.
In the flow rate control valve 20 of the present invention, the opening area of the opening 52 of the flow path changes when the other valve member 60 moves so as to approach the valve member 50.
According to the flow rate control valve 20, a portion of the flow path including the throttle portion 62, which is partially closed by the other valve member 60, can function as an additional throttle portion. Therefore, in the case where it is required to greatly restrict the flow rate per unit time of the fluid flowing in the fluid circuit, it is not necessary to provide the throttle portion having an extremely small sectional size. This makes it possible to easily manufacture the flow rate control valve 20 that exhibits a high flow rate control function. Further, since the portion partially closed by the other valve member 60 (in the present embodiment, the opening portion 52 of the passage 51) functions as a throttle portion whose opening area can be changed by partially closing the other valve member 60 (the end portion 64), it is not necessary to form the portion as a hole having an extremely small cross-sectional size.
When the fluid circuit is a hydraulic circuit, the flow rate of the oil flowing through the throttle portion per unit time is greatly affected by the temperature of the oil. At high temperatures, the viscosity of the oil is small, but at low temperatures, the viscosity of the oil becomes large. In general, since the viscosity of oil has a large temperature dependency, when a throttle portion having an extremely small cross-sectional size is used, the flow rate per unit time of oil flowing through the throttle portion becomes large and the flow rate restriction effect becomes small at a high temperature, while the flow rate per unit time of oil flowing through the throttle portion becomes extremely small and the flow rate control with high accuracy becomes difficult at a low temperature. In contrast, according to the flow rate control valve 20 of the present invention, since the orifice having a relatively large cross-sectional size can be used as the throttle portion 62, the flow rate of the oil flowing through the flow rate control valve 20 per unit time is suppressed from being affected by the temperature of the oil, and a highly accurate flow rate control is possible.
In the flow rate control valve 20 of the present invention, even if the valve structure 40 is reversed in the moving direction, the housing 30 can accommodate the valve structure 40.
According to the flow rate control valve 20, it is possible to obtain a flow rate control valve that performs different functions, particularly a non-impact function in the opposite direction, by merely inverting the valve member 50 and the other valve member 60 in the moving direction of the valve member 50. This can further effectively reduce the number of replacement parts when changing the function of the flow control valve 20.

Claims (7)

1. A flow rate control valve is provided with:
a housing having: two ports; and an internal space having a shape of a stepped portion, connected to the two ports; and
a valve structure body having: a throttle portion provided in a flow path connecting the two ports; a contact portion having a surface not parallel to the moving direction and capable of blocking the other flow path by contacting the stepped portion; and a pressing member that presses the contact portion so that the contact portion can contact the stepped portion of the housing, wherein the valve structure is movably housed in the internal space of the housing.
2. The flow control valve of claim 1,
the contact portion is formed in a valve member, the throttle portion is formed in another valve member, and the pressing member presses the valve member and the another valve member so as to be separated from each other.
3. The flow control valve of claim 1,
the opening area of the opening of the flow path changes when the other valve member moves so as to approach the valve member.
4. The flow control valve of claim 1,
the housing can house the valve structure even if the valve structure is reversed in the moving direction.
5. A flow rate control valve is provided with:
a housing having two ports and an internal space connecting the two ports internally; and
a valve structure body having: a contact portion contactable with one port of the housing in the internal space of the housing; and a throttle portion disposed between the one port and the other port,
a flow path through a throttle portion is formed between the two ports in a state where the contact portion of the valve structure is in contact with the housing,
in a state where the contact portion of the valve structure is separated from the housing, a flow path bypassing the throttle portion is formed.
6. A flow rate control valve is provided with:
a housing having: two ports; and an internal space having a shape of a 1 st step part and a 2 nd step part, connected to the two ports;
a 1 st valve member movably housed in the internal space of the housing, the first valve member including: a 1 st contact part having a surface not parallel to a moving direction and capable of contacting the 1 st step part; a central passage connecting one side and the other side of the 1 st contact part in the moving direction, the one side of the central passage being closed and the other side of the central passage being open; and an opening portion formed in a radial direction from the central passage on the one side of the 1 st contact portion;
a 2 nd valve member movably housed in the internal space of the housing, the 2 nd valve member including: a 2 nd contact portion contactable with the 2 nd step portion of the housing; a shaft portion that is integrally formed with the 2 nd contact portion and is movable in the axial direction in the central passage of the 1 st valve member; a hollow portion of which the one side in the moving direction of the shaft portion is open and the other side is closed; and a throttle portion formed in a radial direction from the hollow portion; and
a pressing member that separates the 1 st valve member and the 2 nd valve member.
7. A working machine comprising the flow control valve according to any one of claims 1 to 6.
CN202010073712.1A 2019-01-23 2020-01-22 Flow control valve and working machine Pending CN111473011A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2019-009525 2019-01-23
JP2019009525A JP7290946B2 (en) 2019-01-23 2019-01-23 Flow control valve and working machine

Publications (1)

Publication Number Publication Date
CN111473011A true CN111473011A (en) 2020-07-31

Family

ID=71747069

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010073712.1A Pending CN111473011A (en) 2019-01-23 2020-01-22 Flow control valve and working machine

Country Status (3)

Country Link
JP (1) JP7290946B2 (en)
KR (1) KR20200091813A (en)
CN (1) CN111473011A (en)

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53130527A (en) * 1978-02-06 1978-11-14 Kyokuto Kaihatsu Kogyo Co Pressure compensating flow quantity controlling valve with check valve
JPH0449688Y2 (en) * 1985-09-06 1992-11-24
JPH03105790U (en) * 1990-02-19 1991-11-01

Also Published As

Publication number Publication date
KR20200091813A (en) 2020-07-31
JP2020118219A (en) 2020-08-06
JP7290946B2 (en) 2023-06-14

Similar Documents

Publication Publication Date Title
US4860788A (en) Metering valve
JP5948260B2 (en) Fluid pressure control device
KR20140138695A (en) Fluid pressure control device
CN110998133B (en) Electric control valve for shock absorber
WO2021059614A1 (en) Flow control valve
JP5571350B2 (en) Hydraulic motor drive device
US10107309B2 (en) Load sensing valve device
US7243493B2 (en) Valve gradually communicating a pressure signal
JP4441386B2 (en) Flow switching type flow divider
JP2019056464A5 (en)
CN111473011A (en) Flow control valve and working machine
JP4994051B2 (en) Hydraulic control device
JP6857571B2 (en) Fluid pressure controller
KR20080077007A (en) Actuator control device
KR102342222B1 (en) Flow control valve and valve structure
JP4791823B2 (en) Hydraulic control valve used in load sensing type hydraulic control device
JP7360858B2 (en) Fluid control equipment and construction machinery
JP7336836B2 (en) Flow control valve and working machine
JP2011106606A (en) Hydraulic motor driving device
JP6836487B2 (en) Control valve
WO2021172098A1 (en) Fluid pressure drive unit
JP7499637B2 (en) Hydraulic motor control device
WO2023189986A1 (en) Flow rate control valve
JPH109415A (en) Control valve with flow control valve and control valve with pressure control valve
JP7397561B2 (en) valve device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination